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Discs large (Dlg) was the first identified member of an increasingly important class of proteins called membrane-associated guanylate kinase homologs (MAGUKs), which are often concentrated at cell junctions and contain distinct peptide domains named PDZ1-3, SH3, HOOK, and GUK. Dlg is localized at and required for the formation of both septate junctions in epithelial cells and synaptic junctions in neurons. In the absence of Dlg, epithelia lose their organization and overgrow. We tested the functions of each domain of Dlg in vivo by constructing transgenic flies expressing altered forms of the protein. In the first set of experiments each domain was examined for its ability to correctly target an epitope-tagged Dlg to pre-existing septate junctions. Based on these results the Hook domain is necessary for localization of the protein to the cell membrane and the PDZ2 is required for restricting the protein to the septate junction. In the second set of experiments each domain was tested for its role in growth regulation and organization of epithelial structure. These results show that PDZ1 and GUK are apparently dispensable for function, PDZ2 and PDZ3 are required for growth regulation but not for epithelial structure, and SH3 and HOOK are essential for both aspects of function. The results demonstrate the functional modularity of Dlg and clarify the functions of individual MAGUK domains in regulating the structure and growth of epithelial tissue.

Patterning of the compound eye begins at the posterior edge of the eye imaginal disc and progresses anteriorly toward the disc margin. The advancing front of ommatidial differentiation is marked by the morphogenetic furrow (MF). Here we show by clonal analysis that Hedgehog (Hh), secreted from two distinct populations of cells has two distinct functions: It was well documented that Hh expression in the differentiating photoreceptor cells drives the morphogenetic furrow. Now we show that, in addition, Hh, secreted from cells at the posterior disc margin, is absolutely required for the initiation of patterning and predisposes ommatidial precursor cells to enter ommatidial assembly later. These two functions of Hh in eye patterning are similar to the biphasic requirement for Sonic Hh in patterning of the ventral neural tube in vertebrates. We show further that Hh induces ommatidial development in the absence of its secondary signals Wingless (Wg) and Dpp and that the primary function of Dpp in MF initiation is the repression of wg, which prevents ommatidial differentiation. Our results show that the regulatory relationships between Hh, Dpp, and Wg in the eye are similar to those found in other imaginal discs such as the leg disc despite obvious differences in their modes of development.

The Drosophila Ras1 gene is required for proper cell fate specification throughout development, and the loss-of-function phenotype of Ras1 suggests an additional role in cell proliferation or survival. A direct role for RAS1 in promoting cell proliferation, however, has not been established. We show that expression of an activated form of RAS1 (RAS1V12) during Drosophila imaginal disc development is sufficient to drive ectopic cell proliferation and hyperplastic tissue growth. In addition, expression of RAS1V12 induces widespread cell death in the imaginal discs, including cells not expressing the transgene, which results in ablation of adult structures. Loss-of-function mutations in the genes encoding RAF, MEK, MAPK and KSR dominantly suppress RAS1V12-induced cell proliferation. Furthermore, two RAS effector loop mutations (E37G and Y40C) that block the RAS-RAF interaction, also suppress RAS1V12-induced proliferation, consistent with a requirement for the MAPK cascade during the RAS1 mitogenic response. These two RAS effector loop mutants, however, retain some activity and can act synergistically with a MAPK gain-of-function mutation, suggesting that RAS1 may also act through signaling pathway(s) distinct from the MAPK cascade.

The mesoderm of Xenopus laevis arises through an inductive interaction in which signals from the vegetal hemisphere of the embryo act on overlying equatorial cells. One candidate for an endogenous mesoderm-inducing factor is activin, a member of the TGFbeta superfamily. Activin is of particular interest because it induces different mesodermal cell types in a concentration-dependent manner, suggesting that it acts as a morphogen. These concentration-dependent effects are exemplified by the response of Xbra, expression of which is induced in ectodermal tissue by low concentrations of activin but not by high concentrations. Xbra therefore offers an excellent paradigm for studying the way in which a morphogen gradient is interpreted in vertebrate embryos. In this paper we examine the trancriptional regulation of Xbra2, a pseudoallele of Xbra that shows an identical response to activin. Our results indicate that 381 bp 5' of the Xbra2 transcription start site are sufficient to confer responsiveness both to FGF and, in a concentration-dependent manner, to activin. We present evidence that the suppression of Xbra expression at high concentrations of activin is mediated by paired-type homeobox genes such as goosecoid, Mix.1, and Xotx2.

A mature inner ear is a complex labyrinth containing multiple sensory organs and nonsensory structures in a fixed configuration. Any perturbation in the structure of the labyrinth will undoubtedly lead to functional deficits. Therefore, it is important to understand molecularly how and when the position of each inner ear component is determined during development. To address this issue, each axis of the otocyst (embryonic day 2.5, E2.5, stage 16-17) was changed systematically at an age when axial information of the inner ear is predicted to be fixed based on gene expression patterns. Transplanted inner ears were analyzed at E4.5 for gene expression of BMP4 (bone morphogenetic protein), SOHo-1 (sensory organ homeobox-1), Otx1 (cognate of Drosophila orthodenticle gene), p75NGFR (nerve growth factor receptor) and Msx1 (muscle segment homeobox), or at E9 for their gross anatomy and sensory organ formation. Our results showed that axial specification in the chick inner ear occurs later than expected and patterning of sensory organs in the inner ear was first specified along the anterior/posterior (A/P) axis, followed by the dorsal/ventral (D/V) axis. Whereas the A/P axis of the sensory organs was fixed at the time of transplantation, the A/P axis for most non-sensory structures was not and was able to be re-specified according to the new axial information from the host. The D/V axis for the inner ear was not fixed at the time of transplantation. The asynchronous specification of the A/P and D/V axes of the chick inner ear suggests that sensory organ formation is a multi-step phenomenon, rather than a single inductive event.

DeltaEF1 is a DNA binding protein containing a homeodomain and two zinc finger clusters, and is regarded as a vertebrate homologue of zfh-1 (zinc finger homeodomain-containing factor-1) in Drosophila. In the developing embryo, deltaEF1 is expressed in the notochord, somites, limb, neural crest derivatives and a few restricted sites of the brain and spinal cord. To elucidate the regulatory function of deltaEF1 in mouse embryogenesis, we generated deltaEF1 null mutant (deltaEF1null(lacZ)) mice. The deltaEF1null(lacZ) homozygotes developed to term, but never survived postnatally. In addition to severe T cell deficiency of the thymus, the deltaEF1null(lacZ) homozygotes exhibited skeletal defects of various lineages. (1) Craniofacial abnormalities of neural crest origin: cleft palate, hyperplasia of Meckel's cartilage, dysplasia of nasal septum and shortened mandible. (2) Limb defects: shortening and broadening of long bones, fusion of carpal/tarsal bone and fusion of joints. (3) Fusion of ribs. (4) Sternum defects: split and asymmetric ossification pattern of the sternebrae associated with irregular sternocostal junctions. (5) Hypoplasia of intervertebral discs. These results indicate that deltaEF1 has an essential role in regulating development of these skeletal structures. Since the skeletal defects were not observed in deltaEF1deltaC727 mice, deltaEF1 bears distinct regulatory activities which are dependent on different domains of the molecule.

The inner ear develops from the otic vesicle, a one-cell-thick epithelium, which eventually transforms into highly complex structures including the sensory organs for balance (vestibulum) and hearing (cochlea). Several mouse inner ear mutations with hearing and balance defects have been described but for most the underlying genes have not been identified, for example, the genes controlling the development of the vestibular organs. Here, we report the inactivation of the homeobox gene, Nkx5-1, by homologous recombination in mice. This gene is expressed in vestibular structures throughout inner ear development. Mice carrying the Nkx5-1 null mutation exhibit behavioural abnormalities that resemble the typical hyperactivity and circling movements of the shaker/waltzer type mutants. The balance defect correlates with severe malformations of the vestibular organ in Nkx5-1(-/-) mutants, which fail to develop the semicircular canals. Nkx5-1 is the first ear-specific molecule identified to play a crucial role in the formation of the mammalian vestibular system.

Mutation of the Unc5h3 (formally known as rcm) gene has important consequences on neuronal migration during cerebellar development. Unc5h3 transcripts are expressed early (embryonic day 8.5) in the hindbrain region and later in the cerebellar primordia. In Unc5h3 mutant embryos, both the development and initial migration of Purkinje cell progenitors occur as in wild-type controls. The rhombic lip, from which granule cell precursors arise, also appears to form normally in mutants. However, at E13.5, an abnormal subpopulation of granule cell and Purkinje cell precursors becomes detectable in rostral areas of the Unc5h3 mutant brain stem. These ectopic cerebellar cells increase in number and continue moving in a rostral direction throughout the remainder of embryogenesis and early stages of postnatal development invading the lateral regions of the pontine area and eventually the inferior colliculus. Cell proliferation markers demonstrate the mitotic nature of these subpial ectopic granule neurons indicating the displacement of the rostral external germinal layer in mutant animals. Our data suggest that establishment of the rostral cerebellar boundary may rely on chemorepulsive signaling events that require UNC5H3 expressed by cerebellar neurons and extracellular ligands that are functionally related to the UNC5H3-binding, guidance molecule netrin1. Although the phenotype resulting from the Unc5h3 mutation is apparently limited to the formation of the cerebellum, additional sites of Unc5h3 expression are also found during development suggesting the compensatory function of other genes.

It has been reported that members of the fibroblast growth factor (FGF) family can induce additional limb formation in the flank of chick embryos. The phenotype of the ectopic limb depends on the somite level at which it forms: limbs in the anterior flank resemble wings, whereas those in the posterior flank resemble legs. Ectopic limbs located in the mid-flank appear chimeric, possessing characteristics of both wings and legs; feather buds are present in the anterior halves with scales and claws in the posterior halves. To study the mechanisms underlying the chimerism of these additional limbs, we cloned chick Tbx5 and Tbx4 to use as forelimb and hindlimb markers and examined their expression patterns in FGF-induced limb buds. We found that Tbx5 and Tbx4 were differentially expressed in the anterior and posterior halves of additional limb buds in the mid-flank, respectively, consistent with the chimeric patterns of the integument. A boundary of Tbx5/Tbx4 exists in all ectopic limbs, indicating that the additional limbs are essentially chimeric, although the degree of chimerism is dependent on the position. The boundary of Tbx5/Tbx4 expression is not fixed at a specific position within the interlimb region, but dependent upon where FGF was applied. Since the ectopic expression patterns of Tbx5/Tbx4 in the additional limbs are closely correlated with the patterns of their chimeric phenotypes, it is likely that Tbx5 and Tbx4 expression in the limb bud is involved in determination of the forelimb and hindlimb identities, respectively, in vertebrates.

Transcriptional silencing can reflect heritable, epigenetic inactivation of genes, either singly or in groups, during the life-time of an organism. This phenomenon is exemplified by parent-of-origin-specific inactivation events (genomic imprinting) for a subset of mammalian autosomal genes, such as H19. Very little is known, however, about the timing and mechanism(s) of silencing of the paternal H19 allele during mouse development. Using a novel in situ approach, we present evidence that the silencing of the paternal H19 allele is progressive in the trophectodermal lineage during early mouse development and generates variegated expression patterns. The silencing process apparently involves recruitment of histone deacetylases since the mosaic paternal-specific H19 expression reappears in trichostatin A-treated mouse conceptuses, undergoing in vitro organogenesis. Moreover, the paternal H19 alleles of PatDup.d7 placentas, in which a region encompassing the H19 locus of chromosome 7 is bipaternally derived, partially escape the silencing process and are expressed in a variegated manner. We suggest that allele-specific silencing of H19 share some common features with chromatin-mediated silencing in position-effect variegation.

The identity and developmental pattern of the four organ types constituting the flower is governed by three developmental functions, A, B and C, which are defined by homeotic genes and established in two adjacent whorls. In this report we morphologically and genetically characterise mutants of two genes, STYLOSA (STY) and FISTULATA (FIS) which control floral homeotic meristem- and organ-identity genes and developmental events in all floral whorls. The morphology of the reproductive organs in the first and second whorls of sty fis double mutant flowers indicate that the two genes are part of the mechanism to prevent ectopic expression of the C-function in the perianth of wild-type flowers. This is verified by the detection of the expansion of the expression domain of the class C gene PLENA (PLE) towards the perianth. Interestingly, in the second whorl of sty and fis mutants, spatial differences in stamenoid features and in the pattern of ectopic expression of the PLE gene were observed. This suggests that, with respect to the negative control of PLE, petals are composed of two regions, a lateral and a central one. Mutation in ple is epistatic to most of the sty/fis-related homeotic defects. PLE, however, is not the primary target of STY/FIS control, because dramatic reduction of expression of FIMBRIATA, meristem identity genes (FLORICAULA and SQUAMOSA) and of class B organ identity genes (GLOBOSA) occur before changes in the PLE expression pattern. We propose that STY/FIS are hierarchically high-ranking genes that control cadastral component(s) of the A-function. SQUAMOSA as a potential target of this control is discussed. Retarded growth of second whorl organs, subdivision of third whorl primordia and the failure to initiate them in sty/fis mutants may be mediated by the FIMBRIATA gene.

The divergent homeobox gene Hex exhibits three notable expression patterns during early mouse development. Initially Hex is expressed in the primitive endoderm of the implanting blastocyst but by 5.5 dpc its transcripts are present only in a small patch of visceral endoderm at the distal tip of the egg cylinder. Lineage analysis shows that these cells move unilaterally to assume an anterior position while continuing to express Hex. The primitive streak forms on the opposite side of the egg cylinder from this anterior Hex expression domain approximately 24 hours after the initial anterior movement of the distal visceral endoderm. Thus, Hex expression marks the earliest unequivocal molecular anteroposterior asymmetry in the mouse embryo and indicates that the anteroposterior axis of the embryo develops from conversion of a proximodistal asymmetry established in the primitive endoderm lineage. Subsequently, Hex is expressed in the earliest definitive endoderm to emerge from the streak and its expression within the gut strongly suggests that the ventral foregut is derived from the most anterior definitive endoderm and that the liver is probably the most anterior gut derivative. Hex is also an early marker of the thyroid primordium. Within the mesoderm, Hex is transiently expressed in the nascent blood islands of the visceral yolk sac and later in embryonic angioblasts and endocardium. Comparison with flk-1 (T. P. Yamaguchi et al., Development 118, 489-498, 1993) expression indicates that Hex is also an early marker of endothelial precursors but its expression in this progenitor population is much more transient than that of flk-1, being downregulated once endothelial cell differentiation commences.

Among the different sources of genetic parthenocarpy described in tomato, the mutation referred to as parthenocarpic fruit (pat) is of particular interest because of its strong expressivity and because it confers earlier ripening, higher fruit set and enhanced fruit quality. As a pleiotropic effect, pat flowers have aberrantly developing androecia and reduced male and female fertility. In this work we extend the early description of the pat phenotype by investigating the expression of parthenocarpy in three different environments and by using light and scanning electron microscopy to analyse the development of male and female floral organs. The degree of parthenocarpy was high in the three experimental environments and was characterised by a precocious initiation of ovary growth to pre-anthesis floral stages. Aberrations in anther development were evident at flower bud stages and resulted in shorter, irregular and teratoid organs. Ectopic production of carpel-like structures bearing external ovules was evident in the most severely altered androecia. Analysis of ovule development revealed that a fraction of pat ovules becomes aberrant from very early stages, having defective integument growth. Meiosis was irregular in aberrant ovules and megaspore or gamete production was severely hampered. The described pat syndrome suggests that parthenocarpy in this mutant could be a secondary effect of a gene controlling, at early stages, organ identity and development.

We are investigating how Drosophila imaginal disc cells establish and maintain their appendage-specific determined states. We have previously shown that ectopic expression of wingless (wg) induces leg disc cells to activate expression of the wing marker Vestigial (Vg) and transdetermine to wing cells. Here we show that ectopic wg expression non-cell-autonomously induces Vg expression in leg discs and that activated Armadillo, a cytosolic transducer of the Wg signal, cell-autonomously induces Vg expression in leg discs, indicating that this Vg expression is directly activated by Wg signaling. We find that ubiquitous expression of wg in leg discs can induce only dorsal leg disc cells to express Vg and transdetermine to wing. Dorsal leg disc cells normally express high levels of decapentaplegic (dpp) and its downstream target, optomotor-blind (omb). We find that high levels of dpp expression, which are both necessary and sufficient for dorsal leg development, are required for wg-induced transdetermination. We show that dorsalization of ventral leg disc cells, through targeted expression of either dpp or omb, is sufficient to allow wg to induce Vg expression and wing fate. Thus, dpp and omb promote both dorsal leg cell fate as well as transdetermination-competent leg disc cells. Taken together, our results show that the Wg and Dpp signaling pathways cooperate to induce Vg expression and leg-towing transdetermination. We also show that a specific vg regulatory element, the vg boundary enhancer, is required for transdetermination. We propose that an interaction between Wg and Dpp signaling can explain why leg disc cells transdetermine to wing and that our results have implications for normal leg and wing development.

The aly, can, mia and sa genes of Drosophila are essential in males both for the G2-meiosis I transition and for onset of spermatid differentiation. Function of all four genes is required for transcription in primary spermatocytes of a suite of spermatid differentiation genes. aly is also required for transcription of the cell cycle control genes cyclin B and twine in primary spermatocytes. In contrast can, mia and sa are required for accumulation of twine protein but not twine transcript. We propose that the can, mia and sa gene products act together or in a pathway to turn on transcription of spermatid differentiation genes, and that aly acts upstream of can, mia and sa to regulate spermatid differentiation. We also propose that control of translation or protein stability regulates entry into the first meiotic division. We suggest that a gene or genes transcribed under the control of can, mia and sa allow(s) accumulation of twine protein, thus coordinating meiotic division with onset of spermatid differentiation.

In Arabidopsis thaliana, shoot redifferentiation and root redifferentiation can be induced at high frequency from hypocotyl and root explants by a two-step culture method. Tissues are precultured on callus-inducing medium and then transferred onto shoot-inducing medium for shoot redifferentiation or onto root-inducing medium for root redifferentiation. In an attempt to dissect these organogenic processes genetically, we characterized the responses in tissue culture of srd1, srd2 and srd3 mutants that were originally isolated as temperature-sensitive strains with defects in shoot redifferentiation (Yasutani, I., Ozawa, S., Nishida, T., Sugiyama, M. and Komamine, A. (1994) Plant Physiol. 105, 815-822). These mutants exhibited temperature sensitivity at different steps of organogenesis, which allowed the identification of three states associated with organogenic competence: IC (incompetent); CR (competent with respect to root redifferentiation); and CSR (competent with respect to shoot and root redifferentiation). Hypocotyl explants were shown to be in the IC state at the initiation of culture and to enter the CSR state, via the CR state, during preculture on callus-inducing medium, whereas root explants seemed to be in the CR state at the initiation of culture. The transition from IC to CR and that from CR to CSR appeared to require the functions of SRD2 and SRD3, respectively. It appears that explants in the CSR state redifferentiate shoots with the aid of the products of SRD1 and SRD2 when transplanted onto shoot-inducing medium. Histological examination of the srd mutants revealed that the function of SRD2 is required not only for organogenesis but also for the reinitiation of cell proliferation in hypocotyl explants during culture on callus-inducing medium. Linkage analysis using RFLP markers indicated that SRD1, SRD2, and SRD3 are located at the lower region, the central region, and the upper region of chromosome 1, respectively.

Early cleavages of the marine nematode Enoplus brevis are symmetrical and occur in synchrony. At the 2- to 16-cell stages, blastomeres are indistinguishable. The progeny of blastomeres was investigated by intracellular injections of fluorescent dyes and horse radish peroxidase. One blastomere of the 2-cell embryo gives rise to a compact group of cells occupying about half of an embryo. The border between labeled and unlabeled cells differs in each embryo dividing it to anterior-posterior, left-right or intermediate parts. At the 8-cell stage, one blastomere gives rise to only endoderm, whereas the other blastomeres produce progeny that form multiple cell types, including nerve, muscle and hypoderm cells, in various proportions. Thus the fates of the blastomeres of early E. brevis embryos, with the exception of the endoderm precursor, are not determined. The process of gastrulation in E. brevis is very similar to that in Caenorhabditis elegans and other nematodes. At the beginning of gastrulation, the 2-celled endoderm precursor lies on the surface of embryo and then sinks inwards. After labeling of cells on the ventral side (near endoderm precursor) at the beginning of gastrulation, their progeny differentiate predominantly into body muscles or pharyngeal cells of the first stage larva. Cells that are located more laterally give rise mainly to neurons. The dorsal blastomeres differentiated principally into hypoderm cells. Our study suggests that a precise cell lineage is not a necessary attribute of nematode development.

Previous investigations involving continuous blood pressure (BP) monitoring have shown an important alteration of the 24-hour BP profile in patients with obstructive sleep apnea syndrome (OSAS). We investigated the impact of REM sleep on the 24-hour BP cycle in 16 severe OSAS male patients (mean respiratory disturbance index = 66 +/- 16 events/hour of sleep), with hypertension (mean BP 162 +/- 21/105 +/- 11 mmHg World Health Organization (WHO) protocol). Two successive nights of polysomnography were performed, and arterial BP was monitored continuously during the second 24-hour period after brachial artery cannulation. During the daytime, subjects were kept awake and supine. At 3 p.m. BP was continuously monitored during quiet supine wakefulness for 20 minutes. Systolic, diastolic and mean BP and heart rate (HR) were analyzed and tabulated in mean values of 5 minute segments. Sleep/wake information were correlated with cardiovascular variables. Each uninterrupted REM sleep period was identified and comparison between the period of quiet supine wakefulness and REM sleep HR and BP values was performed. 8 OSAS patients presented a normal drop of the mean arterial BP during the nocturnal REM sleep periods compared to quiet supine wakefulness (mean value = -10.8 +/- 7.3 mmHg) ("dippers") while the other 8 subjects ("REM sleep non dippers"), revealed an elevated mean arterial BP during REM sleep (mean value = 18.9 +/- 10.9 mm Hg). The absence of the normal circadian BP dip seen during the nocturnal sleep period is considered as an indication of vascular risk. The REM sleep non dipping may play a role in this risk.

Acute renal failure is a serious problem following heart transplantation. In first uncontrolled clinical trials, Urodilatin revealed beneficial effects in the prophylaxis and therapy of acute renal failure following heart and liver transplantation. Here, we present the first randomized, placebo-controlled, double-blind study on 24 patients following heart transplantation to investigate whether prophylactic i.v. Urodilatin infusion can prevent acute renal failure requiring renal replacement therapy. Postoperative drug management was characterized by intravenous application of high furosemide, cyclosporine, and vancomycin doses. Urodilatin infusion was started postoperatively with a dose of 40 ng / kg bw / min for 6 days. 6 of the 12 patients in the Urodilatin group and 6 of the 12 patients in the placebo group had a stable diuresis (3 - 4 l / day) during the study period of 6 days. In contrast, the remaining 6 patients of each group developed oliguria / anuria and required subsequent hemofiltration / hemodialysis. Cumulative duration of hemofiltration (88 +/- 7.39 hours in the placebo treated patients versus 44 +/- 5.35 hours in the Urodilatin treated patients, p < 0. 05) as well as frequency of hemodialysis (3.0 +/- 0.49 times in the placebo group vs 1.2 +/- 0.29 times in the Urodilatin group, p < 0. 05) were significantly reduced using Urodilatin. Mean arterial blood pressure was stable during the Urodilatin infusion period and was not different to that observed in placebo patients. We conclude that Urodilatin does not reduce the incidence of acute renal failure and the subsequent requirement for hemofiltration / hemodialysis in our patient population, but seems to reduce the duration of hemofiltration and frequency of hemodialysis compared to the placebo group.

The arterial wall structure degenerates with increasing age, elastin fibers decrease while collagen increases. We investigated the elastic properties of the aorta and iliac arteries to determine the relationship between aging and arterial mechanics. The regional elasticity of the aorta and iliac arteries was determined at five different sites in 40 normotensive patients aged 32 to 78 years. A combined procedure for arterial blood pressure measurement and arterial cross-sectional area determination was employed to calculate the parameters of compliance and pulse wave velocity. The descending thoracic and abdominal aorta showed significant correlations between age and elasticity. No correlation was observed at the aortic bifurcation. A significant correlation between age and pulse wave velocity was apparent in the common iliac artery, whereas compliance showed no significant correlation to age. In the external iliac artery as well, no significant correlation between age and elasticity could be found. Arterial elasticity decreases with age, but this process does not progress uniformly at all sites of the arterial system. The difference in elasticity between these basic types of arteries diminishes throughout life. At the aortic bifurcation, mechanical aging seems to proceed faster than at unbifurcated arterial segments.

Both inhaled nitric oxide (NO) and inhaled prostacyclin have been shown to selectively decrease pulmonary hypertension of various origin. The aim of the present study was to assess the potential of the NO donor sodium nitroprusside (SNP) to elicit selective pulmonary vasodilation. SNP spontaneously liberates nitric oxide in the presence of reducing substances like cysteine or glutathione, ubiquitous in many different tissues. Inhaled as an aerosol in 3 healthy lambs presenting pulmonary hypertension induced by infusion of a thromboxane analogue, low concentrations of SNP (0.02-0.6 mg/ml) revealed no effect at all. In contrast, high concentrations of SNP (1.0-20.0 mg/ml) lowered pulmonary artery pressure in conjunction with systemic arterial hypotension, suggesting systemic resorption of SNP with subsequent release of its nitroso-group. Selective pulmonary vasodilation was never observed. In conclusion, the present results do not support a selective effect of inhaled SNP in the pulmonary circulation.

Two extracts of St. John s Wort were compared with respect to their action on in vivo monitored field potentials from four brain areas of the freely moving rat. Quantitative assessment of the drug action revealed a late onset (3 to 4 hours after oral application) and main effects on the frontal cortex. Changes consisted in electrical power alterations reminiscent of the action of antidepressive and/or analgesic drugs. Particular frequency bands affected first line were alpha1 and alpha2, which in some way are related to serotonergic and dopaminergic transmission. From this it is concluded that St. Johns Wort could be used for the indication of depression with predictable success. The extract labeled "K" turned out to be superior especially after repetitive application and could thus far be used for further studies.

Central pontine myelinolysis (CPM) is a rare syndrome generally linked to hyponatremia. Autopsy and imaging studies described demyelination in the central pons, in some cases combined with thalamic, internal capsular, hemispheric and cerebellar white matter lesions. The clinical syndrome and prognosis spans from asymptomatic patients displaying only imaging lesions to coma and death. Frequent findings are pyramidal tract and pseudobulbar signs. No effective treatment is known. Alcohol abuse is often associated. The imaging pattern of CPM is unique and generally accepted as diagnostic when other causes such as ischemia, multiple sclerosis, tumors, radiation, or pharmacological effects are ruled out. However, the exact mechanism of this selective process of demyelination remains obscure. The current major controversy concerns the role of therapeutic efforts of sodium level restoration in the etiology of CPM. We present a case of CPM where no hyponatremia was found. We hypothesize that (1) iatrogenic sodium restoration may not in all cases of CPM be the putative mechanism, (2) the clinical onset of CPM may in some patients represent a delayed response to an initially asymptomatic demyelination, and (3) normal admission sodium levels do not exclude the diagnosis of CPM.

Soluble cell adhesion molecules such as sICAM-1 in serum and other biological fluids are suggested as being useful diagnostic parameters for a variety of diseases. Since increased concentrations during diseases are frequently less pronounced compared to other parameters, we tested whether it would be necessary to align the time of blood collection during the course of a clinical trial. In the 9 volunteers of our trial we found a statistically significant effect at the point in time of blood collection and corresponding serum concentrations of sICAM-1 (p < 0.01). The deviation of the concentrations at a certain time from the daily mean in each individual was seen to be as high as 15%. Our data suggest that daytime variations of serum sICAM-1 concentrations should be taken into consideration when longitudinal observations are planned.

We used a new approach called panhandle polymerase chain reaction (PCR) to clone an MLL genomic translocation breakpoint in a case of acute lymphoblastic leukemia of infancy in which karyotype analysis was technically unsuccessful and did not show the translocation partner. Panhandle PCR amplified known MLL sequence 5' of the breakpoint and 3' sequence from the unknown partner gene from a DNA template with an intrastrand loop schematically shaped like a pan with a handle. The 7-kb panhandle PCR product contained the translocation breakpoint in MLL intron 8. The partner DNA included unique nonrepetitive sequences, Alu and mammalian apparent LTR-retrotransposon (MaLR) repetitive sequences, and a region of homology to expressed sequence tags. MaLR sequences have not been found before near leukemia-associated translocation breakpoints. The nonrepetitive sequences were not homologous to known partner genes of MLL. Screening of somatic cell hybrid and radiation hybrid lines by PCR and fluorescence in situ hybridization analysis of normal metaphase chromosomes mapped the partner DNA to chromosome band 4q21. Reverse transcriptase-PCR identified an MLL-AF-4 chimeric mRNA, indicating that panhandle PCR identified a fusion of MLL with a previously uncharacterized AF-4 intronic sequence. Panhandle PCR facilitates cloning translocation breakpoints and identifying unknown partner genes.

p300, which was originally cloned as a nuclear binding target of the adenovirus E1A oncoprotein, forms a family with cyclic-AMP response element binding protein (CREB)-binding protein (CBP). p300/CBP are considered to be transcriptional coactivators that connect the basal transcriptional machinery to various DNA-binding transcriptional factors. p300/CBP are implicated in both cell differentiation and regulation of cell-cycle. We identify here that the p300 gene is fused to the MLL gene and that in-frame MLL-p300 fusion protein is generated in acute myeloid leukemia (AML) with t(11; 22)(q23; q13). These findings suggest that the basis for the leukemogenesis of t(11; 22)-AML is the inability of p300 to regulate cell-cycle and cell differentiation after fusion with MLL.

Chronic graft-versus-host disease (GVHD) is likely caused by donor T lymphocytes. Because unmodified blood stem cell grafts contain one log more T lymphocytes than unmodified marrow grafts, we evaluated the incidence of chronic GVHD in previously reported 37 blood stem cell recipients and 37 computer-matched historical control marrow recipients (Bensinger et al, Blood 88:2794, 1996). All patients have been followed until death, relapse, or occurrence of chronic GVHD or for a minimum of 2 years. In a univariable proportional hazards regression model, the relative risk of developing clinical chronic GVHD (includes clinical limited and clinical extensive disease) by 2 years posttransplant among the peripheral blood stem cell recipients compared with the marrow recipients was 2.22 (95% confidence interval, 1.04 to 4.74; P = .039). For clinical extensive chronic GVHD, the relative risk was 2.37 (95% confidence interval, 1.07 to 5. 29; P = .035). In multivariable analyses, considering also the covariables of patient age, patient cytomegalovirus serostatus, and donor cytomegalovirus serostatus, the relative risks of clinical chronic GVHD and clinical extensive chronic GVHD were also greater than 2 (P < .05). We conclude that the transplantation of unmanipulated filgrastim-mobilized blood stem cells may result in a relatively high incidence of chronic GVHD.

Chemotherapy produces extended remissions, and potential cures, in a small minority of patients with acute myeloid leukemia (AML). We explored whether potentially cured patients were at increased risk of subsequent invasive cancer and were able to return to work. Potentially cured patients were defined as those in first or second complete remission (CR) for at least 3 years based on hazard rates for recurrence or death in CR, which declined sharply after this time. Patients who received allogeneic marrow transplant were excluded. We used questionnaires, phone contact, and chart review to obtain information about subsequent cancer and work status. The number of patients who developed invasive cancer was compared with the number expected based on age, gender, and years of follow-up using the Connecticut Tumor Registry. A total of 215 patients met our criteria for potential cure: 203 in first CR and 12 in second CR (of 1,663 treated between 1965 and December, 1992). At a median of 9.2 years from first or second CR, 163 (76%) remain alive in CR. Fifteen patients developed 18 invasive cancers (expected number of patients, 8.8; observed/expected, 1.70; 95% CI, 0.96 to 2.84; P = . 06). Patients initially treated between 1973 to 1979, patients above the potentially cured cohort's median age of 40 years, and those who presented with abnormalities of chromosomes 5 and/or 7 were more likely to develop subsequent cancer, whereas the observed/expected ratio for younger patients was 1.05 (95% CI, 0.13 to 3.80; P = .56). Seventy-four percent of the patients who were working full-time and who were under age 50 at time of treatment for AML have been working full-time in the last 6 months. Only 17 of 56 patients who are currently not working cited physical limitation as the reason. Patients with potentially cured AML are likely to be able to return to work, and at least if younger do not, on average, have an increased risk of invasive cancer.

The safety and efficacy of filgrastim as an adjunct to acute myeloid leukemia (AML) induction and consolidation therapy was assessed in this prospective double-blind, randomized, placebo-controlled, multicenter trial. A total of 521 consecutive de novo AML patients aged 16 or more years were randomized to receive filgrastim (5 microg/kg/d subcutaneously) or placebo after standard induction as well as consolidation chemotherapy. Blinded study drug was given from 24 hours after chemotherapy until the absolute neutrophil count was >/=1.0 x 10(9)/L for 3 consecutive days. The overall complete remission rate was 68%. After a median follow-up of 24 months (range 5 to 40) the median disease-free survival was 10 months (95% confidence interval [CI], 8.7 to 10.8) and the median overall survival was 13 months (95%CI, 12.2 to 14.6). These did not differ between treatment groups. Patients receiving filgrastim experienced neutrophil recovery 5 days earlier after induction 1 than those receiving placebo (P < .0001). This was accompanied by reductions in the duration of fever (7 v 8.5 days; P = .009), parenteral antibiotic use (15 v 18.5 days; P = .0001), and hospitalization (20 v 25 days; P = .0001). Similar reductions were seen after induction 2 and the consolidation courses. There was a significant reduction in the number of patients requiring systemic antifungal therapy in the filgrastim group during induction treatment (34% v 43%; P = .04). In conclusion, filgrastim is safe in that it had no negative impact on the prognosis of the AML patients. In addition, it effectively reduced the duration of neutropenia, leading to significant clinical benefits by reducing the duration of fever; requirement for parenteral anti-infectives, specifically amphotericin B; and the duration of hospitalization.

To evaluate the usefulness of magnetic resonance imaging for the quantitative determination of hepatic iron, we examined 43 patients with thalassemia major and assessed the influence of pathologic changes in the liver on the precision of estimates of the hepatic iron concentration. Tissue signal intensities were measured from magnetic resonance T1-weighted images derived from gradient-echo (GE) pulse sequences and the ratio of the signal intensity of liver to muscle calculated. By excluding patients (n = 9) having a signal intensity ratio (SIR) less than or equal to 0.2, a linear relationship with hepatic iron was found and subsequent analyses were limited to these 34 patients. In 27 patients with hepatic fibrosis, an overall correlation of -0.848 was found between hepatic iron and SIR. By contrast, in the seven patients with no fibrosis, the correlation coefficient (-0.993) was significantly greater (P < .0001). Despite the differences in correlation, the regression line between hepatic iron and SIR for the patients with no fibrosis did not differ significantly with respect to either slope or intercept from that of the patients with fibrosis. Thus, the presence of fibrosis did not seem to affect the pattern of the relationship between hepatic iron and the SIR, but rather to increase the variability of the relationship. Clinically, the presence of fibrosis makes estimates of hepatic iron derived from magnetic resonance imaging so variable as to be of little practical use in the management of transfusional iron overload.

von Willebrand factor (vWF ) in the presence of botrocetin induces p72(syk) activation, assessed as its autophosphorylated level and in vitro kinase assays, the transient association of p72(syk) with p60(c-src), and the translocation of p60(c-src) and p54/58(lyn) to cytoskeletal fractions. Jararaca glycoprotein Ib-binding protein (GPIb-BP), which specifically binds to GPIb, abolished these phenomena, suggesting that they are mediated by the vWF-GPIb interaction. These tyrosine kinase-related events were not inhibited by GRGDS peptide (plus EGTA), indicating that GPIIb/IIIa is not involved in the observed responses. Shc, an adaptor protein, was also tyrosine phosphorylated by the botrocetin-vWF activation. When GPIb was immunoprecipitated with nonfunctional monoclonal antibodies (MoAbs) directed against GPIb, a kinase activity was found to associate with GPIb upon botrocetin-vWF activation. On the other hand, anti-GPIb MoAbs that inhibit the vWF-GPIb interaction did not coprecipitate a kinase activity. Because the recovery of GPIb did not differ significantly, it is suggested that the excessive presence of inhibitory anti-GPIb MoAb dissociated a kinase activity from GPIb. Phosphoamino acid analysis showed that the kinase activity was that of a tyrosine kinase. The identity of the tyrosine kinase and the mode of interaction with the cytoplasmic region of GPIb await to be determined. Our findings suggest that the tyrosine kinase associated with GPIb serves at a most proximal step in the signal transduction pathway involved in the vWF-GPIb-induced platelet activation, which leads to other tyrosine kinase-related intracellular signals.

A French kindred with autosomal dominant hereditary renal amyloidosis was found to have a novel mutation in the fibrinogen Aalpha-chain gene. In this kindred, renal disease appeared early in life and led to terminal renal failure at an early age. Renal transplantation resulted in rapid destruction of the allograft by amyloid deposition within 2 years. Amyloid fibril protein isolated from a transplanted kidney was found to contain a novel, hybrid peptide of 49 residues whose N-terminal 23 amino acids were identical to residues 499 to 521 of normal fibrinogen Aalpha-chain. The remainder of the peptide (26 residues) represented a completely new sequence for mammalian proteins. DNA sequencing documented that the new sequence was the result of a single nucleotide deletion at position 4897 of the fibrinogen Aalpha-chain gene that gives a frame-shift at codon 522 and premature termination at codon 548. The contributions toward fibrillogenesis of the two portions of the amyloid fibril protein, ie, N-terminal fibrinogen sequence and C-terminal novel sequence, are presently unknown. However, the early onset and rapid reoccurrence of amyloid in renal transplants is unlike the clinical course with other amyloid proteins having single amino acid substitutions that give hereditary renal amyloidosis. Liver transplantation to stop synthesis of this abnormal hepatic derived protein should be considered early in the course of the disease.

A 58-year-old man experienced episodes of fever, vomiting, and diarrhea over a 2-year period. The laboratory evaluation during these attacks consistently disclosed thrombocytopenia, leukopenia, and elevated liver enzymes. A liver biopsy performed at one of these attacks showed a typical picture of granulomatous hepatitis. In retrospect, all episodes seemed to be associated with the ingestion of quinine. Indeed, such a correlation was established by a challenge with quinine. By using flow cytometry, quinine-dependent IgG antibodies to platelets were detected in the patient serum. By a two-color flow cytometric assay, the patient serum was also found to hold quinine-dependent antibodies specific for neutrophils, T lymphocytes, and B lymphocytes. Moreover, serum absorbed with neutrophils in the presence of quinine continued to react with platelets, T lymphocytes, and B lymphocytes; serum that was absorbed with mononuclear cells continued to react with neutrophils and platelets. These experiments indicated that the antigen targets were different on platelets, neutrophils, and lymphocytes. Further, the patient serum in the presence of quinine immunoprecipitated surface-labeled platelet proteins with electrophoretic mobilities closely resembling those of glycoprotein (GP) Ib/IX and GPIIb/IIIa. By a modified monoclonal antibody-specific immobilization of platelet antigens assay, the patient serum in the presence of quinine reacted with platelet GPIb/IX and GPIIb/IIIa. Also, the patient serum in the presence of quinine immunoprecipitated an uncharacterized 15-kD double-band from surface-labeled granulocyte proteins. We conclude that our patient's thrombocytopenia, neutropenia, and lymphocytopenia were caused by quinine-dependent antibodies and that these antibodies recognized cell lineage-specific epitopes.

Microvascular endothelial cells (EC) have multiple functions in inflammatory responses, including the production of chemoattractants that enhance leukocyte transmigration into tissues. Chemotactic protein, 10 kD (CP-10), is an S100 protein with potent chemotactic activity for myeloid cells in vitro and in vivo and is expressed in neutrophils and lipopolysaccharide (LPS)-activated macrophages. We show here that CP-10 is induced in murine endothelioma cell lines (bEnd-3, sEnd-1, and tEnd-1) after activation with LPS and interleukin-1 (IL-1) but not tumor necrosis factor alpha (TNFalpha) or interferon gamma (IFNgamma). Induction was not mediated by endogenous release of IL-1 or TNFalpha and was not directly upregulated by phorbol myristate acetate, calcium ionophore, or vitamin D3. EC were exquisitely sensitive to IL-1 activation (3.4 U/mL) and CP-10 mRNA induction with IL-1 occurred earlier (8 hours) than with LPS (12 hours). Furthermore, some microvessels and capillaries in delayed-type hypersensitivity lesions expressed cytoplasmic CP-10. Responses to LPS and not IL-1 in vitro were regulated by the degree of cell confluence and by TNFalpha costimulation. The related MRP-14 mRNA had a different induction pattern. Monomeric and homodimeric CP-10 upregulated by activation was predominantly cell-associated. EC-derived CP-10 may contribute to amplification of inflammatory processes by enhancing leukocyte shape changes and transmigration in the microcirculation.

Recombinant adeno-associated viruses (rAAV) have been proposed to be gene transfer vehicles for hematopoietic stem cells with advantages over other virus-based systems due to their high titers and relative lack of dependence on cell cycle for target cell integration. We evaluated rAAV vector containing a LacZ reporter gene under the control of a cytomegalovirus (CMV) promoter in the context of primary human CD34+CD2- progenitor cells induced to undergo T-cell differentiation using an in vitro T-lymphopoiesis system. Target cells from either adult bone marrow or umbilical cord blood were efficiently transduced, and 71% to 79% CD2+ cells expressed a LacZ marker gene mRNA and produced LacZ-encoded protein after exposure to rAAV-CMV-LacZ. The impact of transgene expression on the differentiation of T cells was assessed by sequential quantitation of immunophenotypic subsets of virus-exposed cells and no alteration was noted compared with control. The durability of transgene expression was assessed and found to decay by day 35 with kinetics dependent on the multiplicity of infection. In addition, vector DNA was absent from CD4 or CD8 subselected CD3+ cells by DNA-polymerase chain reaction. These data suggest that rAAV vectors may result in robust transgene expression in primitive cells undergoing T-cell lineage commitment without toxicity or alteration in the pattern of T-cell differentiation. However, expression is transient and integration of the transgene unlikely. Recombinant AAV vectors are potentially valuable gene transfer tools for the genetic manipulation of events during T-cell ontogony but their potential in gene therapy strategies for diseases such as acquired immunodeficiency syndrome is limited.

The continual recirculation of lymphocytes between the blood, tissues, and lymph is essential for the coordination and dissemination of immune responses. We have compared the functional and phenotypic properties of lymphocytes isolated from blood and lymph, the two major migratory populations. Lymph-borne lymphocytes migrated readily into the lymphatic recirculation pathway, but greater than one third of all peripheral blood lymphocytes (PBLs) were excluded from the lymphatic circuit and showed an enhanced migration to the spleen. Phenotypic analysis showed that most non-recirculating PBLs were B cells. The migration competence of B cells correlated with the surface expression of CD21 and L-selectin; recirculating B cells expressed both of these molecules, whereas non-recirculating B cells lacked both antigens. These results establish that blood contains distinct pools of lymphocytes that differ in their recirculation competence. Clearly, blood sampling is not an efficient method to directly measure the status of the recirculating immune system, and implies important constraints and restrictions in the interpretation of experimental or clinical data that include phenotypic and quantitative analyses of blood lymphocytes.

Using fluorescence in situ hybridization (FISH) and probes located on 12p12.1 to 13.3, we studied the breakpoints of 23 patients who had various hematologic malignant diseases and who had 12p13-balanced translocations (21 patients), inversion (1 patient), or insertion (1 patient). Among them, 14 patients had breakpoints within YAC964c10, which contains the TEL (ETV6 ) gene and in 12 of these with balanced translocations or insertion, the FISH results suggested that TEL was involved. Two of the 14 patients, patients no. 13 and 14, had breakpoints in YAC 964C10 that were centromeric to TEL but telomeric to KIP1. In the other 9 patients whose breakpoints did not fall within the YAC, the breakpoints were found telomeric to the YAC in at least three different locations on distal 12p. These results indicated that TEL was involved in only half (12 of 23) of the patients with balanced 12p13 rearrangements and that there probably were several other breakpoint cluster regions on 12p13, suggesting that genes other than TEL were involved in these rearrangements.

Primary effusion lymphoma (PEL) represents a novel B-cell non-Hodgkin's lymphoma (NHL) type associated with Kaposi's sarcoma-associated herpesvirus infection and typically growing as lymphomatous effusions in the body cavities. The precise B-cell subset from which PEL originates as well as the biologic mechanisms responsible for its peculiar growth pattern are unclear. In this study, we have analyzed PEL for the expression status of CD138/syndecan-1, a molecule selectively associated with late stages of B-cell differentiation and implicated in cell-to-cell and cell-to-extracellular matrix interactions. PEL patient samples (n = 7) and cell lines (n = 5) were investigated by multiple approaches, including immunocytochemistry, flow cytometry, RNA analysis, and Western blot studies. For comparison, lymphomatous effusions other than PEL (n = 13) and tissue-based NHL (n = 103) were also tested. Expression of CD138/syndecan-1 associates at high frequency with PEL (5 of 7 patient samples and 5 of 5 cell lines), whereas it is consistently absent among other lymphomatous effusions (n = 13). The CD138/syndecan-1 isoform expressed by PEL has an average molecular weight of 420 kD, which is substantially different from that of CD138/syndecan-1 molecules generally expressed by plasma cells. These data, along with previous immunophenotypic evidence, unequivocally define that PEL cells represent a preterminal stage of B-cell differentiation and may bear implications for the peculiar growth pattern of this lymphoma.

Granulocyte-macrophage colony-stimulating factor (GM-CSF ) and tumor necrosis factor alpha (TNFalpha) have been implicated in the pathogenesis of the fatal childhood disease termed juvenile myelomonocytic leukemia (JMML). We used a severe combined immunodeficient/nonobese diabetic (SCID/NOD) mouse model of JMML and examined the effect of inhibiting these cytokines in vivo with the human GM-CSF antagonist and apoptotic agent E21R and the anti-TNFalpha monoclonal antibody (MoAb) cA2 on JMML cell growth and dissemination in vivo. We show here that JMML cells repopulated to high levels in the absence of exogeneous growth factors. Administration of E21R at the time of transplantation or 4 weeks after profoundly reduced JMML cell load in the mouse bone marrow. In contrast, MoAb cA2 had no effect on its own, but synergized with E21R in virtually eliminating JMML cells from the mouse bone marrow. In the spleen and peripheral blood, E21R eliminated JMML cells, while MoAb cA2 had no effect. Importantly, studies of mice engrafted simultaneously with cells from both normal donors and from JMML patients showed that E21R preferentially eliminated leukemic cells. This is the first time a specific GM-CSF inhibitor has been used in vivo, and the results suggest that GM-CSF plays a major role in the pathogenesis of JMML. E21R might offer a novel and specific approach for the treatment of this aggressive leukemia in man.

We previously reported that the abl promoter (Pa) undergoes de novo DNA methylation in the course of chronic myelocytic leukemia (CML). The clinical implications of this finding are the subject of the present study in which samples of CML patients, including a group treated with interferon alpha (IFNalpha) were surveyed. The methylation status of the abl promoter was monitored by polymerase chain reaction (PCR) amplification of the Pa region after digestion with several site-methylation sensitive restriction enzymes. Some 74% of the DNA samples from blood and marrow drawn in the chronic phase were nonmethylated, similar to control samples from non-CML patients. The remaining 26% were partially methylated in the abl Pa region. The latter samples were derived from patients who were indistinguishable from the others on the basis of clinical presentation. Methylated samples were mostly derived from patients known to have a disease of longer duration (26 months v 7.5 months, P = .01). Samples of 30 IFNalpha-treated patients were sequentially analyzed in the course of treatment. Fifteen patients with no evidence of Pa methylation before treatment remained methylation-free. The remainder, who displayed Pa methylation before treatment, reverted to the methylation-free status. The outcome is attributed to IFNalpha therapy, as the Pa methylation status was not reversed in any of the patients treated with hydroxyurea. Methylation of the abl promoter indicates a disease of long-standing, most likely associated with a higher probability of imminent blastic transformation. It appears to predict the outcome of IFNalpha therapy far better than the cytogenetic response.

The translocation t(12; 21)(p13; q22) is difficult to detect by classic cytogenetics. However, using fluorescence in situ hybridization (FISH) and by screening for the TEL/AML1 rearrangement by the polymerase chain reaction (PCR), it has been demonstrated to be the most frequent known structural chromosomal abnormality in childhood acute lymphoblastic leukemia (ALL). It is closely correlated with a B-cell precursor (BCP) phenotype and is considered a favorable prognostic factor. However, little is known about the incidence of the translocation in relapsed patients and the duration of complete remission (CR) in children expressing the TEL/AML1 fusion gene. We therefore examined 49 bone marrow samples from children with ALL at first or second relapse that were consecutively mailed to our laboratory to test for the presence of t(12; 21) using reverse transcriptase (RT)-PCR. The TEL/AML1 rearrangement could be identified in nine of 44 (20%) of the patients, a result similar to the reported incidence at diagnosis. Most of the TEL/AML1-positive children showed no adverse clinical features at diagnosis (eg, white blood cell [WBC] count <100 x 10(9)/L or age <10 years), and regarding these data, there were no differences versus children who were negative for the fusion gene. However, the period of remission was about 1 year longer in children expressing TEL/AML1 (P = .046), and the majority of relapses in this group appeared late (<2 years after diagnosis). Our findings therefore reinforce the urgent need for further prospective studies with a long follow-up period to determine the true prognostic significance of t(12; 21) and to avoid premature changes of treatment strategies.

Structural analysis of naturally processed peptides bound to the HLA class I and class II molecules of chronic myeloid leukemia (CML) blast cells was performed to characterize the antigen processing and autoantigen repertoire in this hematopoietic malignancy. Self-peptides derived from the carboxy-terminal end of the breakpoint cluster region (bcr) protein, as well as several differentiation stage- and tissue-specific self-antigens characteristic of early stages of myeloid differentiation, such as c-fes, c-pim, granulocyte-macrophage colony-stimulating factor receptor alpha chain, proteinase 3, and cathepsin G, were identified. A common characteristic of several of the high copy-number self-peptides identified in this study is the participation of their parent proteins in signal transduction or myeloid effector function. Because bcr-abl junctional peptides bind to a limited number of major histocompatibility complex (MHC) class I alleles, an effective peptide-based immunotherapy strategy for CML requires identification of further tumor-associated or tissue-specific peptide antigens binding to common MHC alleles such as HLA-A2. The differentiation stage- and tissue-specific MHC-bound peptides found in this study, as well as the naturally processed proteins from which they are derived, may represent autoantigens towards which T-cell responses may potentially be developed for immunotherapy of hematopoietic malignancies such as CML.

CGP 57148 is a compound of the 2-phenylaminopyrimidine class that selectively inhibits the tyrosine kinase activity of the ABL and the platelet-derived growth factor receptor (PDGFR) protein tyrosine kinases. We previously showed that CGP 57148 selectively kills p210BCR-ABL-expressing cells. To extend these observations, we evaluated the ability of CGP 57148 to inhibit other activated ABL tyrosine kinases, including p185BCR-ABL and TEL-ABL. In cell-based assays of ABL tyrosine phosphorylation, inhibition of ABL kinase activity was observed at concentrations similar to that reported for p210BCR-ABL. Consistent with the in vitro profile of this compound, the growth of cells expressing activated ABL protein tyrosine kinases was inhibited in the absence of exogenous growth factor. Growth inhibition was also observed with a p185BCR-ABL-positive acute lymphocytic leukemia (ALL) cell line generated from a Philadelphia chromosome-positive ALL patient. As CGP 57148 inhibits the PDGFR kinase, we also showed that cells expressing an activated PDGFR tyrosine kinase, TEL-PDGFR, are sensitive to this compound. Thus, this compound may be useful for the treatment of a variety of BCR-ABL-positive leukemias and for treatment of the subset of chronic myelomonocytic leukemia patients with a TEL-PDGFR fusion protein.

Tumor-derived DNA has been shown in various cell-free body fluids. In this study, soluble tumor-derived DNA was analyzed in serum and plasma samples of patients with B-cell malignancies. DNA was extracted from tumor cell specimens as well as serum and plasma samples collected from 110 patients with non-Hodgkin's lymphoma and acute B-precursor lymphoblastic leukemia and was subjected to polymerase chain reaction (PCR) analysis for rearranged immunoglobulin heavy chain DNA. In 54% of serum or plasma samples analyzed at different times before and during treatment, clonal DNA from a rearranged immunoglobulin heavy chain locus was detectable. When examined at diagnosis and before any treatment, clonotypic DNA was found in serum or plasma of 86% of the patients. Serum or plasma from patients with systemic or bulky disease was uniformly PCR positive, whereas clonotypic DNA was also recovered from the serum or plasma from the majority of patients with limited disease stages. Degradation of clonal DNA by nucleases in vitro was shown to be one cause of false-negative PCR results. This technical drawback can be relieved by adding a nuclease inhibitor like EDTA, ie, by using plasma instead of serum for PCR analysis. Treatment of patients with cytotoxic drugs was followed by rapid clearance of DNA from the peripheral blood, suggesting that soluble tumor-derived DNA might be associated with viable and proliferating tumor cells. Follow-up studies showed a close correlation of persisting soluble tumor-derived DNA with resistant disease or early relapse. In summary, these data suggest that tumor-derived DNA can be detected in serum or plasma of the majority of patients with B-cell malignancies and that testing of serum or plasma for tumor-associated DNA may be a novel parameter for monitoring response to treatment.

Mitochondrial iron overload in acquired idiopathic sideroblastic anemia (AISA) may be attributable to mutations of mitochondrial DNA (mtDNA), because these can cause respiratory chain dysfunction, thereby impairing reduction of ferric iron (Fe3+) to ferrous iron (Fe2+). The reduced form of iron is essential to the last step of mitochondrial heme biosynthesis. It is not yet understood to which part of the respiratory chain the reduction of ferric iron is linked. In two patients with AISA we identified point mutations of mtDNA affecting the same transmembrane helix within subunit I of cytochrome c oxidase (COX I; ie, complex IV of the respiratory chain). The mutations were detected by restriction fragment length polymorphism analysis and temperature gradient gel electrophoresis. One of the mutations involves a T --> C transition in nucleotide position 6742, causing an amino acid change from methionine to threonine. The other mutation is a T --> C transition at nt 6721, changing isoleucine to threonine. Both amino acids are highly conserved in a wide range of species. Both mutations are heteroplasmic, ie, they establish a mixture of normal and mutated mitochondrial genomes, which is typical of disorders of mtDNA. The mutations were present in bone marrow and whole blood samples, in isolated platelets, and in granulocytes, but appeared to be absent from T and B lymphocytes purified by immunomagnetic bead separation. They were not detected in buccal mucosa cells obtained by mouthwashes and in cultured skin fibroblasts examined in one of the patients. In both patients, this pattern of involvement suggests that the mtDNA mutation occurred in a self-renewing bone marrow stem cell with myeloid determination. Identification of two point mutations with very similar location suggests that cytochrome c oxidase plays an important role in the pathogenesis of AISA. COX may be the physiologic site of iron reduction and transport through the inner mitochondrial membrane.

Decomposition of hydrogen peroxide (H2O2 ) at physiological levels was studied in human erythrocytes by means of a recently developed sensitive H2O2 assay. The exponential decay of H2O2 in the presence of purified erythrocyte catalase was followed down to 10(-9) mol/L H2O2 at pH 7.4. H2O2 decomposition by purified erythrocyte glutathione peroxidase (GPO) could be directly observed down to 10(-7) mol/L H2O2 . No enzyme inhibition was observed at these low H2O2 concentrations. Catalase and GPO activities can be determined separately in a titrated mixture of purified enzymes, which simulates the conditions of H2O2 removal by the erythrocyte. Experiments with fresh human hemolysate allowed us to determine H2O2 decomposition by catalase and GPO using these enzymes in their original quantitative ratio. The different kinetics of these enzymes are shown: H2O2 decomposition by catalase depends linearly on H2O2 concentration, whereas that by GPO becomes saturated at concentrations above 10(-6) mol/L H2O2. Even at very low H2O2 concentrations GPO reaches only approximately 8% of the rate at which catalase simultaneously degrades H2O2. These data indicate an almost exclusive role for catalase in the removal of H2O2 in normal human erythrocytes.

The possibility that serum ferritin is a secreted protein and an acute phase reactant regulated by inflammatory hormones and iron was examined in a hepatic cell line that secretes plasma proteins. Differentiated rat hepatoma cells released albumin and ferritin into the medium, as determined by rocket immunoelectrophoresis and isolation of ferritin by standard procedures plus immunoaffinity chromatography, following labeling with radioactive amino acid. Administration of interleukin-1-beta (IL-1) or tumor necrosis factor-alpha (TNF) doubled the amounts of ferritin released into the medium over 24 and 48 hours. Together, the cytokines had more than an additive effect. Albumin secretion was diminished by IL-1, but not TNF. Iron, administered as an iron dextran complex or as a 1:1 chelate with nitrilotriacetate (Fe-NTA), also enhanced ferritin release, but had no effect on albumin. Intracellular ferritin concentrations did not change significantly with cytokine treatment, but increased in response to iron. With or without treatments, release of ferritin and albumin from cells into the medium was inhibited by brefeldin A, an inhibitor of Golgi function. The effect of each of the cytokines and of iron on ferritin and albumin was also blocked by dichlorofuranosylbenzimidazole (DRB), an inhibitor of transcription. The stimulatory effect of Fe-NTA on ferritin secretion was diminished by TNF, and this was partially counteracted by IL-1, indicating additional regulatory complexity. These results show for the first time that hepatic cells secrete ferritin, that this ferritin secretion is regulated by iron and inflammatory cytokines, and that the mechanisms of regulation differ from those for intracellular ferritin. The results would explain why serum ferritin increases in inflammation or when iron flux is enhanced.

We present a novel G1091 to A mutation in the human liver and red blood cell (RBC) pyruvate kinase (PK) gene causing severe hemolytic anemia. In two families, three children were severely PK-deficient compound heterozygotes exhibiting the G1091 to A mutation and a common G1529 to A mutation on the other allele. In one family, the mother, a G1091 to A heterozygote, later had a second baby with a new husband, also a G1091 to A carrier. The baby was homozygous for the G1091 to A mutation and died 6 weeks after birth from severe hemolysis. Both mutant alleles were expressed at the RNA level. The G1091 to A mutation results in the substitution of a conserved glycine by an aspartate in domain A of RBC PK, whereas the G1529 to A mutation leads to the substitution of a conserved arginine residue with glutamine in the C-domain. Molecular modelling of human RBC PK, based on the crystal structure of cat muscle PK, shows that both mutations are located outside the catalytic site at the interface of domains A and C. The mutations are likely to disrupt the critical conformation of the interface by introducing alternative salt bridges. In this way the Gly364 to Asp and Arg510 to Gln substitutions may cause PK deficiency by influencing the allosteric properties of the enzyme.

Hematopoietic growth factors allow dose escalation of chemotherapy. This approach may potentially reduce the quality and quantity of hematopoietic stem cells. The capacity of stem cells recovered after dose intensification to support myeloablative therapy is unknown. In patients with previously untreated advanced follicular lymphoma, trilineage hematopoietic engraftment was compared in two sequential trials of induction therapy (standard dose cyclophosphamide, doxorubicin, vincristine, prednisone [CHOP] without growth factors or dose intensification CHOP supported by granulocyte colony-stimulating factor [G-CSF ]) followed by identical myeloablative therapy and autologous stem cell support. Neutrophil, platelet, and red blood cell (RBC) engraftment were compared on days 100, 180, and 360 after stem cell reinfusion. Despite similar patient characteristics including reinfusion of comparable numbers of marrow mononuclear cells, after stem cell transplantation, a highly significant prolongation of neutrophil and platelet engraftment was seen in patients who received high dose CHOP and G-CSF in comparison to standard dose CHOP. These findings suggest that dose intensified chemotherapy and G-CSF recruited stem cells into a proliferative phase and that G-CSF allowed retreatment at a time when stem cells were susceptible to damage by cytotoxic therapy. Such inadequate hematologic engraftment after myeloablative therapy might be avoided by either shortening the time that growth factor support is administered, lengthening the interval between cycles, or attempting to repetitively harvest additional stem cells either from the marrow or peripheral blood. Therefore, intensification of chemotherapy with growth factor support must be used with caution if stem cells are to be used to support myeloablative therapy.

Phenotypic analysis of hematopoietic stem and progenitor cells (HSCs) has been an invaluable tool in defining the biology of stem cell populations. We have recently described the production of AC133, a monoclonal antibody (MoAb) that binds to a novel cell surface antigen present on a CD34(bright) subset of human HSCs. This antigen is a glycosylated protein with a molecular weight of 120 kD. Here, we report the molecular cloning of a cDNA encoding this antigen and show that it does not share homology with any previously described hematopoietic or other cell surface antigen(s). The AC133 polypeptide has a predicted size of 97 kD and contains five-transmembrane (5-TM) domains with an extracellular N-terminus and a cytoplasmic C-terminus. Whereas the expression of tetraspan (4-TM) and 7-TM molecules is well documented on mature and immature hematopoietic cells and leukocytes, this 5-TM type of structure containing two large (255-amino acid [aa] and 290-aa) extracellular loops is unique and does not share sequence homology with any known multi-TM family members. Expression of this protein appears limited to bone marrow in normal tissue by immunohistochemical staining; however, Northern analysis suggests that the mRNA transcript is present in a variety of tissues such as the kidney, pancreas, placenta, and fetal liver. The AC133 antigen is also expressed on subsets of CD34+ leukemias, suggesting that it may be an important early marker for HSCs, as well as the first described member of a new class of TM receptors.

Autosomal dominant hypophosphatemic rickets (ADHR) is an inherited disorder of isolated renal phosphate wasting, the pathogenesis of which is unknown. We performed a genome-wide linkage study in a large kindred to determine the chromosome location of the ADHR gene. Two-point LOD scores indicate that the gene is linked to the markers D12S314 [Z(theta) = 3.15 at theta = 0.0], vWf [Z(theta) = 5.32 at theta = 0.0], and CD4 [Z(theta) = 3.53 at theta = 0.0]. Moreover, multilocus analysis indicates that the ADHR gene locus is located on chromosome 12p13 in the 18-cM interval between the flanking markers D12S100 and D12S397. These data are the first to establish a chromosomal location for the ADHR locus and to provide a framework map to further localize the gene. Such studies will permit ultimate identification of the ADHR gene and provide further insight into phosphate homeostasis.

Complete interferon-gamma receptor 1 (IFNgammaR1) deficiency has been identified previously as a cause of fatal bacillus Calmette-Guérin (BCG) infection with lepromatoid granulomas, and of disseminated nontuberculous mycobacterial (NTM) infection in children who had not been inoculated with BCG. We report here a kindred with partial IFNgammaR1 deficiency: one child afflicted by disseminated BCG infection with tuberculoid granulomas, and a sibling, who had not been inoculated previously with BCG, with clinical tuberculosis. Both responded to antimicrobials and are currently well without prophylactic therapy. Impaired response to IFN-gamma was documented in B cells by signal transducer and activator of transcription 1 nuclear translocation, in fibroblasts by cell surface HLA class II induction, and in monocytes by cell surface CD64 induction and TNF-alpha secretion. Whereas cells from healthy children responded to even low IFN-gamma concentrations (10 IU/ml), and cells from a child with complete IFNgammaR1 deficiency did not respond to even high IFN-gamma concentrations (10,000 IU/ml), cells from the two siblings did not respond to low or intermediate concentrations, yet responded to high IFN-gamma concentrations. A homozygous missense IFNgR1 mutation was identified, and its pathogenic role was ascertained by molecular complementation. Thus, whereas complete IFNgammaR1 deficiency in previously identified kindreds caused fatal lepromatoid BCG infection and disseminated NTM infection, partial IFNgammaR1 deficiency in this kindred caused curable tuberculoid BCG infection and clinical tuberculosis.

Uncoupling protein-2 and -3 (UCP2 and UCP3) are mitochondrial proteins that show high sequence homology with the brown adipocyte-specific UCP1. UCP1 induces heat production by uncoupling respiration from ATP synthesis. UCP2 is widely expressed in human tissues, whereas UCP3 expression seems restricted to skeletal muscle, an important site of thermogenesis in humans. We have investigated the regulation of UCP2 and UCP3 gene expression in skeletal muscle and adipose tissue from lean and obese humans. UCP2 and -3 mRNA levels were not correlated with body mass index (BMI) in skeletal muscle, but a positive correlation (r = 0.55, P < 0.01, n = 22) was found between UCP2 mRNA level in adipose tissue and BMI. The effect of fasting was investigated in eight lean and six obese subjects maintained on a hypocaloric diet (1,045 kJ/d) for 5 d. Calorie restriction induced a similar 2-2.5-fold increase in UCP2 and -3 mRNA levels in lean and obese subjects. To study the effect of insulin on UCP gene expression, six lean and five obese subjects underwent a 3-h euglycemic hyperinsulinemic clamp. Insulin infusion did not modify UCP2 and -3 mRNA levels. In conclusion, the similar induction of gene expression observed during fasting in lean and obese subjects shows that there is no major alteration of UCP2 and -3 gene regulation in adipose tissue and skeletal muscle of obese subjects. The increase in UCP2 and -3 mRNA levels suggests a role for these proteins in the metabolic adaptation to fasting.

Basal cell carcinoma (BCC) is the most common skin cancer in humans, and although metastasis rarely occurs, the tumor cells are nevertheless able to invade and destroy the surrounding tissue. Intralesional injection of IFN-alpha has been found to be highly effective in inducing BCC regression by an unknown mechanism. We show that in untreated patients, BCC cells express CD95 ligand, but not the receptor, which may allow tumor expansion by averting the attack of activated CD95 receptor-positive lymphoid effector cells. The CD95 ligand of BCC cells is functional as CD95-positive cells incubated on BCC cryosections become apoptotic and are lysed. In IFN-alpha-treated patients BCC cells express not only CD95 ligand but also CD95 receptor, whereas the peritumoral infiltrate that mainly consists of CD4+ T cells predominantly contains CD95 receptor and only few CD95 ligand-positive cells. Thus, in treated patients BCC most likely regresses by committing suicide through apoptosis induction via CD95 receptor-CD95 ligand interaction.

Transgenic mice overexpressing a constitutively active human TGF-beta1 under control of the rat phosphoenolpyruvate carboxykinase regulatory sequences developed fibrosis of the liver, kidney, and adipose tissue, and exhibited a severe reduction in body fat. Expression of the transgene in hepatocytes resulted in increased collagen deposition, altered lobular organization, increased hepatocyte turnover, and in extreme cases, hemorrhage and thrombosis. Renal expression of the transgene was localized to the proximal tubule epithelium, and was associated with tubulointerstitial fibrosis, characterized by excessive collagen deposition and increased fibronectin and plasminogen activator inhibitor-1 immunoreactivity. Pronounced glomerulosclerosis was evident, and hydronephrosis developed with low penetrance. Expression of TGF-beta1 in white and brown adipose tissue resulted in a lipodystrophy-like syndrome. All white fat depots and brown fat pads were severely reduced in size, and exhibited prominent fibroplasia. This reduction in WAT was due to impaired adipose accretion. Introduction of the transgene into the ob/ob background suppressed the obesity characteristic of this mutation; however, transgenic mutant mice developed severe hepato- and splenomegaly. These studies strengthen the link between TGF-beta1 expression and fibrotic disease, and demonstrate the potency of TGF-beta1 in modulating mesenchymal cell differentiation in vivo.

Although bile acid transport by bile duct epithelial cells, or cholangiocytes, has been postulated, the details of this process remain unclear. Thus, we performed transport studies with [3H]taurocholate in confluent polarized monolayers of normal rat cholangiocytes (NRC). We observed unidirectional (i.e., apical to basolateral) Na+-dependent transcellular transport of [3H]taurocholate. Kinetic studies in purified vesicles derived from the apical domain of NRC disclosed saturable Na+-dependent uptake of [3H]taurocholate, with apparent Km and Vmax values of 209+/-45 microM and 1.23+/-0.14 nmol/mg/10 s, respectively. Reverse transcriptase PCR (RT-PCR) using degenerate primers for both the rat liver Na+-dependent taurocholate-cotransporting polypeptide and rat ileal apical Na+-dependent bile acid transporter, designated Ntcp and ASBT, respectively, revealed a 206-bp product in NRC whose sequence was identical to the ASBT. Northern blot analysis demonstrated that the size of the ASBT transcript was identical in NRC, freshly isolated cholangiocytes, and terminal ileum. In situ RT-PCR on normal rat liver showed that the message for ASBT was present only in cholangiocytes. Immunoblots using a well-characterized antibody for the ASBT demonstrated a 48-kD protein present only in apical membranes. Indirect immunohistochemistry revealed apical localization of ASBT in cholangiocytes in normal rat liver. The data provide direct evidence that conjugated bile acids are taken up at the apical domain of cholangiocytes via the ASBT, and are consistent with the notion that cholangiocyte physiology may be directly influenced by bile acids.

Irreversible exit from the cell cycle precludes the ability of cardiac muscle cells to increase cell number after infarction. Using adenoviral E1A, we previously demonstrated dual pocket protein- and p300-dependent pathways in neonatal rat cardiac myocytes, and have proven that E2F-1, which occupies the Rb pocket, suffices for these actions of E1A. By contrast, the susceptibility of adult ventricular cells to viral delivery of exogenous cell cycle regulators has not been tested, in vitro or in vivo. In cultured adult ventricular myocytes, adenoviral gene transfer of E2F-1 induced expression of proliferating cell nuclear antigen, cyclin-dependent protein kinase 4, cell division cycle 2 kinase, DNA synthesis, and apoptosis. In vivo, adenoviral delivery of E2F-1 by direct injection into myocardium induced DNA synthesis, shown by 5'-bromodeoxyuridine incorporation, and accumulation in G2/M, by image analysis of Feulgen-stained nuclei. In p53(-)/- mice, the prevalence of G1 exit was more than twofold greater; however, E2F-1 evoked apoptosis and rapid mortality comparably in both backgrounds. Thus, the differential effects of E2F-1 on G1 exit in wild-type versus p53-deficient mice illustrate the combinatorial power of viral gene delivery to genetically defined recipients: E2F-1 can override the G1/S checkpoint in postmitotic ventricular myocytes in vitro and in vivo, but leads to apoptosis even in p53(-)/- mice.

Obesity is associated with diabetes, and leptin is known to be elevated in obesity. To investigate whether leptin has a direct effect on insulin secretion, isolated rat and human islets and cultured insulinoma cells were studied. In all cases, mouse leptin inhibited insulin secretion at concentrations within the plasma range reported in humans. Insulin mRNA expression was also suppressed in the cultured cells and rat islets. The long form of the leptin receptor (OB-Rb) mRNA was present in the islets and insulinoma cell lines. To determine the significance of these findings in vivo, normal fed mice were injected with two doses of leptin. A significant decrease in plasma insulin and associated rise in glucose concentration were observed. Fasted normal and leptin receptor-deficient db/db mice showed no response to leptin. A dose of leptin, which mimicked that found in normal mice, was administered to leptin-deficient, hyperinsulinemic ob/ob mice. This caused a marked lowering of plasma insulin concentration and a doubling of plasma glucose. Thus, leptin has a powerful acute inhibitory effect on insulin secretion. These results suggest that the action of leptin may be one mechanism by which excess adipose tissue could acutely impair carbohydrate metabolism.

HIV infection is characterized by the reduction of the CD4+, CD45RA+, CD26+, and CD28+ lymphocyte subsets and of the in vitro production of IL-2, IL-4, and interferon-gamma; on the contrary, chemokine production is usually increased. These abnormalities are only partially restored by antiretroviral chemotherapy. Therapy with interleukin-2 has been proposed to restore the functions of the immune system, but the mechanisms by which IL-2 exerts its activities are unknown. The aim of this study was to define the effects of rIL-2 administration on CD4+, CD45RA+, CD45R0+, and CD26+ lymphocytes and on the in vitro production of IL-2, IL-4, IL-10, IFN-gamma, RANTES, and sCD30 in HIV+ patients. 10 HIV+ patients with CD4 cell counts between 200 and 500 cells/mm3 were treated with six cycles of subcutaneous recombinant IL-2 administration, in combination with zidovudine and didanosine. This therapeutic regimen resulted in a remarkable increase in the number of CD4+ cells and in the prolonged reduction of the levels of viremia. CD45R01 cells were expanded during the first cycle of therapy, while CD45RA+/CD26+ cells predominated after the third cycle. At this time, the in vitro production of IL-2, IL-4, IFN-gamma, and sCD30 were significantly upregulated. These results demonstrate that rIL-2 in HIV+ patients induces the reconstitution of the CD4/CD45RA lymphocytes subtype. This expanded cell population recovered the ability to produce in vitro IL-2, IL-4, and IFN-gamma. These effects may be beneficial to HIV+ patients by improving their immune response to microorganisms or vaccines.

Transgenic mice overexpressing the human growth hormone gene develop mammary carcinomas. Since human growth hormone gene can activate both the growth hormone receptor (GHR) and the prolactin (PRL) receptor (PRLR), it is not clear which receptor system is responsible for the malignant transformation. To clarify the receptor specificity, we created transgenic mice with two different genes: (a) transgenic mice overexpressing the bovine growth hormone (bGH) gene having high levels of bGH only activating the GHR and also high serum levels of IGF-I; and (b) transgenic mice overexpressing the rat PRL (rPRL) gene that have elevated levels of PRL (one line 150 ng/ml and one line 13 ng/ml) only binding to the PRLR and with normal IGF-I levels. When analyzed histologically, all of the PRL transgenic female mice developed mammary carcinomas at 11-15 mo of age. Only normal mammary tissue was observed among the bGH transgenic animals and the controls. Cell lines established from a tumor produced rPRL and expressed PRLR. In organ culture experiments, an auto/paracrine effect of rPRL was demonstrated. In conclusion, activation of the PRLR is sufficient for induction of mammary carcinomas in mice, while activation of the GHR is not sufficient for mammary tumor formation.

Endothelial cells initiate the inflammatory response by recruiting and activating leukocytes. IL-6 is not an agonist for this, but we found soluble IL-6 receptor alpha-subunit (IL-6Ralpha), with their constitutive IL-6 synthesis, stimulated endothelial cells to synthesize E-selectin, intracellular adhesion molecule-1, vascular cellular adhesion molecule-1, IL-6, and IL-8, and to bind neutrophils. Neutrophils express significant amounts of IL-6Ralpha and upon stimulation shed it: this material activates endothelial cells through a newly constituted IL-6 receptor. Retrograde signaling from PMN activated in the extravascular compartment to surrounding endothelial cells will recruit more and a wider variety of leukocytes. The limiting signal is a soluble receptor, not a cytokine.

Multiple clinical trials have shown the efficacy of adoptively transferred allogeneic antigen-specific T cells for the treatment of viral infections and relapsed hematologic malignancies. In contrast, the therapeutic potential of autologous antigen-specific T cells has yet to be established since it has been technically difficult to generate sufficient numbers of these T cells, ex vivo. A major obstacle to the success of this objective derives from our inability to simply and rapidly isolate and/or expand large numbers of highly efficient antigen presenting cells (APCs) for repetitive stimulations of antigen-specific T cells in vitro. We show that autologous CD40-activated B cells represent a readily available source of highly efficient APC that appear to have several important advantages over other APCs for ex vivo T cell expansion including: (a) methodological simplicity necessary to generate continuously large numbers of APCs from just 50 cm3 of peripheral blood without loss of APC function; (b) capacity to induce high peak T cell proliferation and interferon-gamma production without IL-10 production; (c) ease in cryopreservation; and (d) markedly reduced cost. We, therefore, contend that CD40-activated B cells are an alternative source of highly efficient APCs with which to generate antigen-specific T cells ex vivo for autologous adoptive immunotherapy.

Cytokines, in particular tumor necrosis factor-alpha (TNF-alpha), have significant effects on energy metabolism and appetite although their mechanisms of action are largely unknown. Here, we examined whether TNF-alpha modulates the production of leptin, the recently identified fat-specific energy balance hormone, in cultured adipocytes and in mice. TNF-alpha treatment of 3T3-L1 adipocytes resulted in rapid stimulation of leptin accumulation in the media, with a maximum effect at 6 h. This stimulation was insensitive to cycloheximide, a protein synthesis inhibitor, but was completely inhibited by the secretion inhibitor brefeldin A, indicating a posttranslational effect. Treatment of mice with TNF-alpha also caused a similar increase in plasma leptin levels. Finally, in obese TNF-alpha-deficient mice, circulating leptin levels were significantly lower, whereas adipose tissue leptin was higher compared with obese wild-type animals. These data provide evidence that TNF-alpha can act directly on adipocytes to regulate the release of a preformed pool of leptin. Furthermore, they suggest that the elevated adipose tissue expression of TNF-alpha that occurs in obesity may contribute to obesity-related hyperleptinemia.

Mucin 1 (MUC1) is a large complex glycoprotein that is highly expressed in breast cancer, and as such could be a target for immunotherapy. In mice, human MUC1 is highly immunogenic, particularly when conjugated to mannan, where a high frequency of CD8(+) MHC-restricted cytotoxic T lymphocytes is induced, accompanied by tumor protection. On this basis, a clinical trial was performed in which 25 patients with advanced metastatic carcinoma of breast, colon, stomach, or rectum received mannan-MUC1 in increasing doses. After 4 to 8 injections, large amounts of IgG1 anti-MUC1 antibodies were produced in 13 out of 25 patients (with antibody titers by ELISA of 1/320-1/20,480). Most of the antibodies reacted to the epitopes STAPPAHG and PAPGSTAP. In addition, T cell proliferation was found in 4 out of 15 patients, and CTL responses were seen in 2 out of 10 patients. Mannan-MUC1 can immunize patients, particularly for antibody formation, and to a lesser extent, cellular responses. It remains to be seen whether such responses have antitumor activity.

The endothelium plays an important role in maintaining the vascular homeostasis by releasing vasodilator substances, including prostacyclin (PGI2), nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF). Although the former two substances have been investigated extensively, the importance of EDHF still remains unclear, especially in human arteries. Thus we tested our hypothesis that EDHF plays an important role in human arteries, particularly with reference to the effect of vessel size, its vasodilating mechanism, and the influences of risk factors for atherosclerosis. Isometric tension and membrane potentials were recorded in isolated human gastroepiploic arteries and distal microvessels (100-150 microm in diameter). The contribution of PGI2, NO, and EDHF to endothelium-dependent relaxations was analyzed by inhibitory effects of indomethacin, NG-nitro- L-arginine, and KCl, respectively. The nature of and hyperpolarizing mechanism by EDHF were examined by the inhibitory effects of inhibitors of cytochrome P450 pathway and of various K channels. The effects of atherosclerosis risk factors on EDHF-mediated relaxations were also analyzed. The results showed that (a) the contribution of EDHF to endothelium-dependent relaxations is significantly larger in microvessels than in large arteries; (b) the nature of EDHF may not be a product of cytochrome P450 pathway, while EDHF-induced hyperpolarization is partially mediated by calcium-activated K channels; and (c) aging and hypercholesterolemia significantly impair EDHF-mediated relaxations. These results demonstrate that EDHF also plays an important role in human arteries.

In cystic fibrosis (CF), defective function of the cystic fibrosis transmembrane conductance regulator (CFTR) in airway epithelial cells and submucosal glands results in chronic pulmonary infection with Pseudomonas aeruginosa. The pulmonary infection incites an intense host inflammatory response, causing progressive suppurative pulmonary disease. Mouse models of CF, however, fail to develop pulmonary disease spontaneously. We examined the effects of bronchopulmonary infection on mice homozygous for the S489X mutation of the CFTR gene using an animal model of chronic Pseudomonas endobronchial infection. Slurries of sterile agarose beads or beads containing a clinical isolate of mucoid P. aeruginosa were instilled in the right lung of normal or CF mice. The mortality of CF mice inoculated with Pseudomonas-laden beads was significantly higher than that of normal animals: 82% of infected CF mice, but only 23% of normal mice, died within 10 d of infection (P = 0.023). The concentration of inflammatory mediators, including TNF-alpha, murine macrophage inflammatory protein-2, and KC/N51, in bronchoalveolar lavage fluid in CF mice 3 d after infection and before any mortality, was markedly elevated compared with normal mice. This inflammatory response also correlated with weight loss observed in both CF and normal littermates after inoculation. Thus, this model may permit examination of the relationship of bacterial infections, inflammation, and the cellular and genetic defects in CF.

Vascular proliferative disorders are characterized by the proliferation of vascular smooth muscle cells (SMCs) and excessive extracellular matrix synthesis. We found that bone morphogenetic protein-2 (BMP-2) inhibited serum-stimulated increases in DNA synthesis and cell number of cultured rat arterial SMCs in a fashion quite different from that in the case of transforming growth factor-beta1 (TGF-beta1). In addition, TGF-beta1 stimulated collagen synthesis in SMCs, whereas BMP-2 did not. In an in vivo rat carotid artery balloon injury model, the adenovirus-mediated transfer of the BMP-2 gene inhibited injury-induced intimal hyperplasia. These results indicate that BMP-2 has the ability to inhibit SMC proliferation without stimulating extracellular matrix synthesis, and suggest the possibility of therapeutic application of BMP-2 for the prevention of vascular proliferative disorders.

Non-insulin-dependent diabetes mellitus (NIDDM) is caused by peripheral insulin resistance and impaired beta cell function. Phosphofructo-1-kinase (PFK1) is a rate-limiting enzyme in glycolysis, and its muscle subtype (PFK1-M) deficiency leads to the autosomal recessively inherited glycogenosis type VII Tarui's disease. It was evaluated whether PFK1-M deficiency leads to alterations in insulin action or secretion in humans. A core family of four members was evaluated for PFK1-M deficiency by DNA and enzyme-activity analyses. All members underwent oral and intravenous glucose tolerance tests (oGTT and ivGTT) and an insulin-sensitivity test (IST) using octreotide. Enzyme activity determinations in red blood cells showed that the father (46 yr, body mass index [BMI] 22. 4 kg/m2) and older son (19 yr, BMI 17.8 kg/m2) had a homozygous, while the mother (47 yr, BMI 28.4 kg/m2) and younger son (13 yr, BMI 16.5 kg/m2) had a heterozygous PFK1-M deficiency. DNA analyses revealed an exon 5 missense mutation causing missplicing of one allele in all four family members, and an exon 22 frameshift mutation of the other allele of the two homozygously affected individuals. The father showed impaired glucose tolerance, and the mother showed NIDDM. By ivGTT, both parents and the older son had decreased first-phase insulin secretion and a diminished glucose disappearance rate. The IST showed marked insulin resistance in both parents and the older, homozygous son, and moderate resistance in the younger son. PFK1-M deficiency causes impaired insulin secretion in response to glucose, demonstrating its participation in islet glucose metabolism, and peripheral insulin resistance. These combined metabolic sequelae of PFK-1 deficiency identify it as a candidate gene predisposing to NIDDM.

Vitamin C concentrations in the brain exceed those in blood by 10-fold. In both tissues, the vitamin is present primarily in the reduced form, ascorbic acid. We identified the chemical form of vitamin C that readily crosses the blood-brain barrier, and the mechanism of this process. Ascorbic acid was not able to cross the blood-brain barrier in our studies. In contrast, the oxidized form of vitamin C, dehydroascorbic acid (oxidized ascorbic acid), readily entered the brain and was retained in the brain tissue in the form of ascorbic acid. Transport of dehydroascorbic acid into the brain was inhibited by d-glucose, but not by l-glucose. The facilitative glucose transporter, GLUT1, is expressed on endothelial cells at the blood-brain barrier, and is responsible for glucose entry into the brain. This study provides evidence showing that GLUT1 also transports dehydroascorbic acid into the brain. The findings define the transport of dehydroascorbic acid by GLUT1 as a mechanism by which the brain acquires vitamin C, and point to the oxidation of ascorbic acid as a potentially important regulatory step in accumulation of the vitamin by the brain. These results have implications for increasing antioxidant potential in the central nervous system.

We investigated the mechanism by which inosine, a metabolite of adenosine that accumulates to > 1 mM levels in ischemic tissues, triggers mast cell degranulation. Inosine was found to do the following: (a) compete for [125I]N6-aminobenzyladenosine binding to recombinant rat A3 adenosine receptors (A3AR) with an IC50 of 25+/-6 microM; (b) not bind to A1 or A2A ARs; (c) bind to newly identified A3ARs in guinea pig lung (IC50 = 15+/-4 microM); (d) lower cyclic AMP in HEK-293 cells expressing rat A3ARs (ED50 = 12+/-5 microM); (e) stimulate RBL-2H3 rat mast-like cell degranulation (ED50 = 2.3+/-0.9 microM); and (f) cause mast cell-dependent constriction of hamster cheek pouch arterioles that is attenuated by A3AR blockade. Inosine differs from adenosine in not activating A2AARs that dilate vascular smooth muscle and inhibit mast cell degranulation. The A3 selectivity of inosine may explain why it elicits a monophasic arteriolar constrictor response distinct from the multiphasic dilator/constrictor response to adenosine. Nucleoside accumulation and an increase in the ratio of inosine to adenosine may provide a physiologic stimulus for mast cell degranulation in ischemic or inflamed tissues.

Systemic delivery of specific therapeutic proteins by a parenteral route of administration is a recognized practice in the management of several gene defects and acquired diseases. As an alternative to repetitive parenteral administration, gene therapy may provide a novel means for systemic delivery of therapeutic proteins while improving patient compliance and therapeutic efficacy. However, for gene therapy to be an efficacious and safe approach to the clinical management of such diseases, gene expression must be tightly regulated. These investigations demonstrate precise in vivo control of protein expression from cells that are engineered to secrete human growth hormone (hGH) in response to stimulation by rapamycin. The cells were implanted intramuscularly into nu/nu mice and stimulated by intravenous or oral administration of rapamycin. In vivo experiments demonstrate that the activity and pharmacokinetics of rapamycin determine the level of serum hGH that result from the engineered cells. In addition, responsiveness of the cells to rapamycin, number of cells implanted, hGH expression kinetics, and the pharmacokinetics of hGH itself, also influence the circulating levels of hGH after rapamycin stimulation. Controlled manipulation of several of these parameters, either independently or in combination, allows for precise regulation of circulating hGH concentration in vivo.

Fanconi anemia (FA) consists of a group of at least five autosomal recessive disorders that share both clinical (e.g., birth defects and hematopoietic failure) and cellular (e.g., sensitivity to cross-linking agents and predisposition to apoptosis) features with each other. However, a common pathogenetic link among these groups has not been established. To identify genetic pathways that are altered in FA and characterize shared molecular defects, we used mRNA differential display to isolate genes that have altered expression patterns in FA cells. Here, we report that the expression of an interferon-inducible gene, MxA, is highly upregulated in cells of FA complementation groups A, B, C, and D, but it is suppressed in FA group C cells complemented with wild-type FAC cDNA as well as in non-FA cells. A posttranscriptional mechanism rather than transcriptional induction appears to account for MxA overexpression. Forced expression of MxA in Hep3B cells enhances their sensitivity to mitomycin C and induces apoptosis, similar to the FA phenotype. Thus, MxA is a downstream target of FAC and is the first genetic marker to be identified among multiple FA complementation groups. These data suggest that FA subtypes converge onto a final common pathway, which is intimately related to the interferon signaling mechanism. Constitutive activity of this pathway may explain a number of the phenotypic features of FA, particularly the pathogenesis of bone marrow failure.

Re-epithelialization of skin wounds depends upon the migration of keratinocytes from the cut margins of the wound and is enhanced when human keratinocytes are covered with occlusive dressings that induce hypoxia. In this study, two independent migration assays were used to compare cellular motility on connective tissue components under normoxic or hypoxic conditions. Human keratinocytes apposed to collagens or fibronectin exhibited increased motility when subjected to hypoxic (0.2 or 2% oxygen) conditions compared with normoxic (9 or 20% oxygen) conditions. When compared with normoxic cells, hypoxic keratinocytes exhibited increased expression and redistribution of the lamellipodia-associated proteins (ezrin, radixin, and moesin). Furthermore, hypoxic keratinocytes demonstrated decreased secretion of laminin-5, a laminin isoform known to inhibit keratinocyte motility. Hypoxia did not alter the number of integrin receptors on the cell surface, but did induce enhanced secretion of the 92-kD type IV collagenase. These data demonstrate that hypoxia promotes human keratinocyte motility on connective tissue. Hypoxia-driven motility is associated with increased expression of lamellipodia proteins, increased expression of collagenase and decreased expression of laminin-5, the locomotion brake for keratinocytes.

Myocardial glucose use is regulated by competing substrates and hormonal influences. However, the interactions of these effectors on the metabolism of exogenous glucose and glucose derived from endogenous glycogen are not completely understood. In order to determine changes in exogenous glucose uptake, glucose oxidation, and glycogen enrichment, hearts were perfused with glucose (5 mM) either alone, or glucose plus insulin (40 microU/ml), glucose plus acetoacetate (5 mM), or glucose plus insulin and acetoacetate, using a three tracer (3H, 14C, and 13C) technique. Insulin-stimulated glucose uptake and lactate production in the absence of acetoacetate, while acetoacetate inhibited the uptake of glucose and the oxidation of both exogenous glucose and endogenous carbohydrate. Depending on the metabolic conditions, the contribution of glycogen to carbohydrate metabolism varied from 20-60%. The addition of acetoacetate or insulin increased the incorporation of exogenous glucose into glycogen twofold, and the combination of the two had additive effects on the incorporation of glucose into glycogen. In contrast, the glycogen content was similar for the three groups. The increased incorporation of glucose in glycogen without a significant change in the glycogen content in hearts perfused with glucose, acetoacetate, and insulin suggests increased glycogen turnover. We conclude that insulin and acetoacetate regulate the incorporation of glucose into glycogen as well as the relative contributions of exogenous glucose and endogenous carbohydrate to myocardial energy metabolism by different mechanisms.

We have investigated the antidiabetic action of troglitazone in aP2/DTA mice, whose white and brown fat was virtually eliminated by fat-specific expression of diphtheria toxin A chain. aP2/DTA mice had markedly suppressed serum leptin levels and were hyperphagic, but did not gain excess weight. aP2/DTA mice fed a control diet were hyperlipidemic, hyperglycemic, and had hyperinsulinemia indicative of insulin-resistant diabetes. Treatment with troglitazone alleviated the hyperglycemia, normalized the tolerance to intraperitoneally injected glucose, and significantly decreased elevated insulin levels. Troglitazone also markedly decreased the serum levels of cholesterol, triglycerides, and free fatty acids both in wild-type and aP2/DTA mice. The decrease in serum triglycerides in aP2/DTA mice was due to a marked reduction in VLDL- and LDL-associated triglyceride. In skeletal muscle, triglyceride levels were decreased in aP2/DTA mice compared with controls, but glycogen levels were increased. Troglitazone treatment decreased skeletal muscle, but not hepatic triglyceride and increased hepatic and muscle glycogen content in wild-type mice. Troglitazone decreased muscle glycogen content in aP2/DTA mice without affecting muscle triglyceride levels. The levels of peroxisomal proliferator-activated receptor gamma mRNA in liver increased slightly in aP2/DTA mice and were not changed by troglitazone treatment. The results demonstrate that insulin resistance and diabetes can occur in animals without significant adipose deposits. Furthermore, troglitazone can alter glucose and lipid metabolism independent of its effects on adipose tissue.

The intermediate filament vimentin might play a key role in vascular resistance to mechanical stress. We investigated the responses to pressure (tensile stress) and flow (shear stress) of mesenteric resistance arteries perfused in vitro from vimentin knockout mice. Arteries were isolated from homozygous (Vim-/-, n = 14) or heterozygous vimentin-null mice (Vim+/-, n = 5) and from wild-type littermates (Vim+/+, n = 9). Passive arterial diameter (175+/-15 micron in Vim+/+ at 100 mmHg) and myogenic tone were not affected by the absence of vimentin. Flow-induced (0-150 microl/min) dilation (e. g., 19+/-3 micron dilation at 150 mmHg in Vim+/+) was significantly attenuated in Vim-/- mice (13+/-2 micron dilation, P < 0.01). Acute blockade of nitric oxide synthesis (NG-nitro- L-arginine, 10 microM) significantly decreased flow-induced dilation in both groups, whereas acute blockade of prostaglandin synthesis (indomethacin, 10 microM) had no significant effect. Mean blood pressure, in vivo mesenteric blood flow and diameter, and mesenteric artery media thickness or media to lumen ratio were not affected by the absence of vimentin. Thus, the absence of vimentin decreased selectively the response of resistance arteries to flow, suggesting a role for vimentin in the mechanotransduction of shear stress.

The mechanisms that regulate vascular resistance in the liver are an area of active investigation. Previously, we have shown that nitric oxide (NO) modulates hepatic vascular tone in the normal rat liver. In this study, the production of NO is examined in further detail by isolating sinusoidal endothelial cells (SEC) from the rat liver. Endothelial NO synthase (eNOS) was present in SEC based on Western blotting and confocal immunofluorescence microscopy. Exposure of SEC to flow increased the release of NO. To investigate the relevance of these in vitro findings to the intact liver, we modified an in situ perfusion system to allow for direct measurement of NO release from the hepatic vasculature. NO was released from the hepatic vasculature in a time-dependent manner, and administration of N-monomethyl-L-arginine reduced NO release and increased portal pressure. Immunostaining of intact liver demonstrated eNOS localization to endothelial cells lining the hepatic sinusoids. These findings demonstrate that SEC in vitro and in vivo express eNOS and produce NO basally, and increase their production in response to flow. Additionally, an increase in portal pressure concomitant with the blockade of NO release directly demonstrates that endogenous endothelial-derived NO modulates portal pressure.

Detection of specific nuclear transcripts by fluorescence in situ hybridization (FISH) has constituted a major breakthrough in the study of the organization of transcription in the cell nucleus. Using the model of heat shock genes, we present an optimized procedure for nuclear transcripts that provides high efficiency for RNA detection and good preservation of cell morphology and nuclear texture. Using this procedure, we designed an original high-efficiency methodology combining FISH and fluorescence immunocytochemistry (FICC), which is used here for the simultaneous detection of heat-shock protein (hsp) nuclear transcripts and the specific heat-shock transcription factor 1 (HSF1). We show that the nuclear accumulation sites of HSF1 in heat-shocked cells do not correspond to the sites of transcription of the hsp70 gene.

Activin stimulates the synthesis and secretion of follicle-stimulating hormone (FSH). It inhibits the synthesis and release of growth hormone (GH). It acts on gonadotropes by stimulating the synthesis of gonadotropin-releasing hormone (GnRH) receptors. To test activin's effects on GnRH target cells, pituitary cells from diestrous or proestrous rats were exposed to media with and without 60 ng/ml activin for 24 hr and stimulated with biotinylated GnRH (Bio-GnRH). The populations were double-labeled for Bio-GnRH and/or luteinizing hormone-beta (LH-beta), FSH-beta, or GH antigens. In both diestrous and proestrous rats, activin stimulated more LH and FSH cells and increased the percentages of GnRH target cells. In diestrous rats, activin stimulated increases in the average area and density of Bio-GnRH label on target cells. In addition, more FSH, LH, and GH cells bound Bio-GnRH. The increment in binding by gonadotropes was not as great as that normally seen from diestrus to proestrus, suggesting that additional factors (such as estradiol) may be needed. These data suggest that activin plays an important role in the augmentation of Bio-GnRH target cells normally seen before ovulation. Its actions on GH cells may reflect a role in the transitory change from a somatotrope to a somatogonadotrope that is seen from diestrus to proestrus.

We examined the distribution of copper-zinc superoxide dismutase (CuZnSOD) in adult rat central nervous system by light and electron microscopic immunocytochemistry, using an affinity-purified polyclonal antibody. The enzyme appeared to be exclusively localized in neurons. No immunoreactivity was seen in non-neuronal cells. The staining intensity was variable, depending on the brain region and, within the same region, on the neuron type. Highly immunoreactive elements included cortical neurons evenly distributed in the different layers, hippocampal interneurons, neurons of the reticular thalamic nucleus, and Golgi, stellate, and basket cells of the cerebellar cortex. Other neurons, i.e., pyramidal cells of the neocortex and hippocampus, Purkinje and granule cells of the cerebellar cortex, and the majority of thalamic neurons, showed much weaker staining. In the spinal cord, intense CuZnSOD immunoreactivity was present in many neurons, including motor neurons. Pre-embedding immunoelectron microscopy of the neocortex, hippocampus, reticular thalamic nucleus, and cerebellar cortex showed cytosolic and nucleoplasmic labeling. Moreover, single membrane-limited immunoreactive organelles identified as peroxisomes were often found, even in neurons that appeared weakly stained at the light microscopic level. In double immunogold labeling experiments, particulate CuZnSOD immunoreactivity co-localized with catalase, a marker enzyme for peroxisomes, thus demonstrating that in neural tissue CuZnSOD is also present in peroxisomes.

Pro-thyrotropin-releasing hormone (pro-TRH) has been shown to be present throughout the central nervous system and in several peripheral tissues. In adrenals, TRH immunoreactivity has been reported but not characterized. We show here that two rat pro-TRH-derived peptides, TRH and prepro-TRH[160-169] (Ps4), were detected in extracts of rat adrenal glands by enzyme immunoassay. Endogenous TRH and Ps4 were purified by gel exclusion chromatography and reverse-phase HPLC. Structural identification of each peptide was achieved by chromatographic comparison with synthetic standards. By using the indirect immunofluorescence technique, TRH-immunoreactive cell bodies were found rather widely scattered outside the adrenal, in the brown adipose tissue in which the gland is embedded. These immunofluorescent cells have the typical appearance of mast cells and are metachromatic after histological staining with acidic Toluidine Blue. Our findings suggest that pro-TRH-derived peptides exist in rat mast cells.

Quantitation of antigen concentration in cell and tissue samples typically requires antigen extraction, which precludes antigen localization in the same sample. Similarly, antigen immunolocalization in fixed cells or tissue sections provides limited information about antigen concentration. We have developed a rapid and sensitive assay for simultaneous antigen localization and quantitation in cell and tissue samples that does not involve antigen extraction, radioactive materials, or image analysis. Fixed cells and/or tissue sections are used with antigen-specific enzyme-linked probes to generate soluble reaction products that are spectrophotometrically quantifiable and deposited reaction products that are microscopically localizable. The amount of soluble reaction product is dependent on several variables, including antigen concentration, probe specificity and sensitivity, sample size, and enzyme reaction time. These variables can be experimentally controlled so that soluble reaction product is proportional to antigen concentration in the sample. This assay was used in multiple applications including detection of Ki-67 nuclear antigen immunoreactivity in human brain tumors, in which it showed a clear relationship with visually determined Ki-67 cell labeling indexes. This assay, termed the Midwestern assay, should be applicable to a wide variety of antigens in both clinical and research samples.

Neuropeptide Y (NPY) and peptide YY (PYY) are structurally related peptides that are considered to mediate inhibitory actions on gastrointestinal motility, secretion, and blood flow. Several receptor subtypes for these peptides have been identified and the Y1, Y2, Y4/PP1, Y5, and Y5/PP2/Y2b receptors have been cloned. In this article we report the immunocytochemical localization of the Y1 receptor to myenteric and submucosal nerve cell bodies, endothelial cells, and scattered endocrine-like cells of rat intestinal tract. Moreover, double immunofluorescence demonstrates that subpopulations of the Y1 receptor-positive nerve cell bodies are immunopositive for NPY, vasoactive intestinal polypeptide, and nitric oxide synthase. In part, such co-localizations were made possible by use of peroxidase-mediated deposition of tyramide, which permitted use of antisera derived from the same species. Our observations suggest the existence of multiple neuronal, endothelial, and endocrine target sites for NPY and PYY and that some of the actions of these regulatory peptides can be mediated by vasoactive intestinal peptide and nitric oxide synthase.

Gene-specific probes labeled with fluorescein, Texas Red, and digoxigenin-11 dUTP (DIG) were used for RT in situ PCR hybridization to detect PIG-A gene (phosphatidylinositol glycan class A) transcripts. The PIG-A gene is responsible for biosynthesis of the glycosylphosphatidyl-inositol (GPI) anchor. Lack of GPI anchor expression due to mutations can cause an acquired clonal hematologic disorder called paroxysmal nocturnal hemoglobinuria (PNH). In this RT in situ PCR study, two types of labeling methods, a direct method (using fluorescein and Texas Red) and an indirect method (using DIG-11 dUTP) were compared. Both were successfully applied to detect and localize the PIG-A gene transcripts within single cells of the cell lines AA2, H9, and JY. Furthermore, similar results for sensitivity and reproducibility were obtained. Advantages and disadvantages of the different labeling techniques are discussed. In addition, peripheral blood mononuclear cells from PNH patients were also included in this study.

Immunohistochemical methods are widely used for diagnostic purposes in histopathology. However, the use of most monoclonal anti-leukocyte antibodies is limited to frozen tissues. Initially, it was believed that formalin fixation in particular, which is the gold standard for morphological tissue preservation, destroys most of the antigen binding sites. In recent years, protease digestion and the introduction of microwave techniques have significantly enhanced the sensitivity of immunohistochemical techniques, and a variety of hidden antigen sites in formalin-fixed tissue have been retrieved for initially unreactive antibodies. It therefore became clear that many of the leukocyte antigens are not irreversibly destroyed but are most probably masked during the fixation process. We developed a technique combining optimized pretreatment of formalin-fixed tissue with a dramatic enhancement of the immunohistochemical sensitivity and named it the ImmunoMax method. The ImmunoMax method proves that by optimizing the technique at the following three levels it is possible to detect formalin-sensitive leukocyte antigens: (a) standard fixation of the tissue; (b) sufficient antigen unmasking; and (c) increasing the substrate turnover by multiplication of binding sites with subsequent enhancement of the immunohistochemical reaction. Using this optimized ImmunoMax method, we were able to detect CD2, CD3, CD4, and CD5 with conventional monoclonal antibodies in formalin-fixed, paraffin-embedded tissue specimens of various lymphoid tissues.

In this immunocytochemical study, we used light and electron microscopic observations in combination with morphometry to analyze the processing of pro-opiomelanocortin (POMC) in melanotrope cells of the intermediate pituitary of Xenopus laevis adapted to either a white or a black background. An antiserum was raised against a synthetic peptide including the cleavage site between ACTH and beta-lipotropic hormone in Xenopus. Western blotting revealed that this antiserum recognizes only a 38-kD protein, the POMC prohormone, from extracts of Xenopus neurointermediate pituitary. Light immunocytochemistry showed differential immunostaining for anti-POMC compared to anti-alpha-MSH. Anti-POMC was predominantly found in the perinuclear region, whereas anti-alpha-MSH yielded staining throughout the cytoplasm. Immunogold double labeling revealed that electron-dense secretory granules (DGs) show high immunoreactivity for anti-POMC and low immunoreactivity for anti-alpha-MSH. Electron-lucent granules (LGs) are immunoreactive to anti-alpha-MSH only. Moderately electron-dense granules (MGs) revealed intermediate reactivity compared to DGs and LGs. Background light intensity has significant effects on the morphology and the immunoreactivity of the secretory granules. Black-adapted animals have 4.5 times as many DGs and MGs as white-adapted animals. In addition, the MGs in black animals show 42% more anti-alpha-MSH immunogold than the MGs in white animals. Together, these findings indicate that the three granule types represent subsequent stages in granule maturation. Adaptation to a black background stimulates the formation of young immature granules, while at the same time the processing rate during granule maturation increases.

The tumor suppressor maspin (mammary serpin) was originally identified as a component of human mammary epithelial cells that is downregulated as mammary tumor cells progress from the benign to the invasive and metastatic states. Maspin inhibits cellular invasion, motility, and proliferation, but its mechanism of action is currently unknown. Because the cellular machinery responsible for these processes is cytoplasmic, we have reexamined the tissue distribution and subcellular localization of maspin. We find that maspin, or a maspin-like protein, is present in many human organs, in which it localizes to epithelia. In cultured human mammary myoepithelial cells, maspin is predominantly a soluble cytoplasmic protein that associates with secretory vesicles and is present at the cell surface. In vitro assays show that the vesicle association is due to the existence of an uncleaved facultative secretion signal that allows small amounts of maspin to partition into the endoplasmic reticulum. These results demonstrate that maspin is more widespread than previously believed. The subcellular localization studies indicate that soluble intracellular and vesicle-associated maspin probably play an important role in controlling the invasion, motility, and proliferation of cells expressing it, whereas extracellular maspin may also regulate these processes in adjacent cells.

Paraffin embedding of tissue is generally perceived to dramatically reduce RNA detectability. As a consequence, in situ hybridization on paraffin-embedded tissue is largely confined to detection of high-copy RNA species (e.g., viral RNA) and/or to detection using typically more sensitive cDNA probes or riboprobes. In this study, several procedures for in situ hybridization on paraffin-embedded rat tissue using oligonucleotide probes complementary to cellular transcripts were developed and quantitatively compared. Certain pretreatments showed marked increases in sensitivity compared to untreated sections. Furthermore, through quantitative assessment using image analysis, sensitivity of optimal pretreatments was equal to that of routinely used fresh-frozen, postfixed tissue sections. The development of such techniques permitting in situ hybridization to be carried out on paraffin-embedded tissue allows a comparison of protein and mRNA distribution to be made in adjacent sections and provides the potential for double labeling by in situ hybridization and immunohistochemistry which may not be possible on post-fixed frozen sections.

Mast cells are difficult to purify from heterogeneous cell populations and to preserve, especially for pre-embedding immunostaining at the ultrastructural level. We have developed a technique that permits the isolation of a pure population of mast cells suitable for immunocytochemical studies. A rat mast cell-specific monoclonal antibody (MAb AA4) conjugated to tosylactivated Dynabeads 450 was used to immunomagnetically separate mast cells from rat bone marrow and peritoneal cell suspensions. Approximately 85% of the mast cells were recovered in the positive population that comprised virtually pure mast cells. After microwave fixation, morphological examination showed that the cells were intact and retained their ultrastructural detail. Mast cells in all stages of maturation were immunolabeled with a panel of antibodies after immunomagnetic separation. The combination of immunomagnetic separation followed by immunostaining should prove useful for the study of mast cell maturation and for the characterization of other specific cell types that are present in tissues in only limited numbers.

OBJECTIVE To define the metabolic profile of postmenopausal hormone replacement therapies when delivered through gels, patches, implants or other non-oral routes. Such information may be useful in the absence of reliable clinical data on the effects of these therapies on the risk of cardiovascular disease. DESIGN AND METHODS Selective literature review. PATIENTS Postmenopausal women. RESULTS Non-oral oestrogen therapies fail to invoke the hepatic response associated with oral therapy. Changes in hepatic protein synthesis are minimal and so plasma levels of binding globulins and other proteins tend to be normal. Many of the perturbations of the haemostatic system seen with oral therapy are avoided. In the absence of hepatic over-synthesis of apolipoproteins, plasma lipoprotein levels are unchanged or reduced. The direct effects of oestrogen on vascular function are apparent when the hormone is administered non-orally. CONCLUSIONS The net effect of non-oral estrogen therapies on the risk of cardiovascular disease is difficult to predict on the basis of current data. Some changes in plasma lipoprotein levels, such as the reduced fasting levels of triglycerides, would be considered desirable, but the cardioprotective increase in levels of high-density lipoproteins is absent. The differential effect on haemostasis markers is promising, but preliminary data relating to transdermal patches fail to support the idea that non-oral therapies will avoid the increased risk of venous thromboembolism associated with oral therapy. The ability of non-oral therapies to improve vascular function implies that they will offer postmenopausal women at least some of the cardiovascular protection seen with oral therapy.

OBJECTIVE To compare two doses of a transdermal oestradiol gel (Divigel/Sandrena) plus oral sequential medroxyprogesterone acetate (MPA) with oral oestradiol valerate plus oral sequential MPA (Divina/Dilena). DESIGN Two year, randomised, open-label, comparative study. SETTING Menopausal outpatient clinic in Helsinki. SUBJECTS Postmenopausal women with climacteric complaints or already using HRT. INTERVENTIONS (1) One gram gel containing 1 mg oestradiol for 3 months plus 20 mg oral MPA during the last 14 days; (2) 2 g gel containing 2 mg oestradiol for 21 days plus 10 mg oral MPA during the last 14 days; (3) 2 mg oestradiol valerate tablets for 3 weeks plus 10 mg oral MPA during the last 10 days. In all groups, each treatment period was followed by a 7-day medication-free interval. MAIN OUTCOME MEASURES Climacteric complaints, bleeding control, bone mineral density, biomarkers of bone metabolism, lipid profile, tolerability and safety. RESULTS With each preparation, climacteric complaints were significantly reduced and good bleeding control was obtained. In addition, maintenance of bone mineral density as well as a reduction of bone turnover was achieved in all groups. Lipid parameters showed no unfavourable changes. Continuation rates were similar in all groups with overall 74% of patients completing the first year, whereas 94% of patients who elected to continue completed the second year. Tolerability of the gel was good: only 1.7% of patients discontinued treatment due to skin irritation. CONCLUSIONS Transdermal oestradiol gel and oral oestradiol valerate tablets, used in combination with oral sequential MPA, are effective regimens of HRT in postmenopausal women. Transdermal oestradiol gel is an efficient, well-tolerated form of HRT.

OBJECTIVE To evaluate the effects of 1 g (1 mg oestradiol) transdermal oestradiol gel continuously combined with 10 mg medroxyprogesterone acetate orally 12 days either monthly or every third month on haemostasis variables. DESIGN An open, parallel stratified study. SETTING Sahlgrenska University Hospital, Göteborg, Sweden. PARTICIPANTS A total of 48 peri- and postmenopausal women less than 65 years of age participated in this study. Twenty-seven women, who had from 2 months to 3 years since their last period were included in group I. Twenty-one women, who were more than 3 years postmenopausal, comprised group II. MAIN OUTCOME MEASURES The following parameters were determined: von Willebrand factor antigen, factor VII antigen, fibrinogen, antithrombin, protein C, protein S, plasminogen activator inhibitor activity, tissue plasminogen activator antigen, prothrombin fragment 1 + 2, thrombin-antithrombin complex and platelets. RESULTS Both regimens decreased fibrinogen, factor VII antigen as well as antithrombin. CONCLUSIONS These changes were mainly 'in an anti-thrombotic direction'. The overall impression is that the transdermally administered oestrogen in combination with an oral progestogen induced favourable, although slight changes in the haemostatic system. The possible influence of these changes on the risk of cardiovascular disease remains yet to be studied.

OBJECTIVE To investigate changes in plasma lipid and lipoprotein levels induced by peroral oestrogen replacement and transdermal oestradiol gel therapy. DESIGN The effects of peroral oestradiol valerate tablets (2 mg) and placebo gel were compared with 1g transdermal oestradiol gel (1mg oestradiol) and placebo tablets in a randomised, double-blind, double-dummy study for 6 months. SETTING Department of Internal Medicine, University of Oulu and Oulu Deaconess Institute, Oulu, Finland. POPULATION Seventy-nine hysterectomised, postmenopausal women, 39 women in the peroral oestrogen group and 40 in the gel group. MAIN OUTCOME MEASURES Cholesterol and triglycerides in total plasma and in various lipoprotein fractions, and sex hormones. RESULTS In the peroral oestrogen group total and LDL cholesterol were decreased and HDL cholesterol and triglycerides were increased. In the oestradiol gel group plasma total, LDL and VLDL cholesterol and the ratio of LDL/HDL cholesterol were significantly decreased, but no change in HDL cholesterol and triglycerides was observed. Overall the decrease in LDL levels was correlated with the increase in oestrogen levels. CONCLUSIONS Both peroral and transdermal replacement therapy had beneficial effects on plasma lipids by lowering total and LDL cholesterol and LDL/HDL cholesterol ratio. These changes seem to be associated with changes in oestrogen levels.

Intestinal epithelial cells (i-EC), which move to the villus tips from the crypts, rapidly die by apoptosis at the villus tips and are perpetually renewed at the crypts. To determine whether the Fas antigen (Fas)/Fas ligand (FasL) system is involved in the mechanism leading to apoptosis of i-EC, we examined the expression of Fas and FasL on the i-EC and intestinal intraepithelial lymphocytes (i-IEL) in normal mice. A high level of Fas was expressed on both the i-EC and i-IEL, whereas FasL was expressed in the i-IEL, especially in high-density fraction upon separation (high-density i-IEL), but not in the i-EC. The high-density i-IEL exhibited cytotoxicity against not only Fas transfectant but also the i-EC, and the cytotoxicity was inhibited by addition of Fas-Fragment c chimeric fusion protein. Thus, a significant fraction of i-IEL, such as high-density i-IEL, may partly contribute to induction of apoptosis in the effete i-EC via Fas/FasL interaction.

Platelet-derived growth factor (PDGF) is synthesized and secreted by mesenchymal cells. We used immunohistochemistry and in situ hybridization to determine whether immunoreactivity for PDGF and PDGF receptor (PDGF-R) might be a prognostic indicator in lung carcinoma. We compared these results with those of immunohistochemistry for anti-proliferating cell nuclear antigen (anti-PCNA). Indirect immunohistochemistry and in situ hybridization were performed for PDGF B-chain, PDGF-R beta and PCNA antibodies, and PDGF B mRNA on frozen, paraffin-embedded sections of 92 surgically resected lung carcinomas (39 squamous cell carcinomas, 47 adenocarcinomas, 2 large-cell carcinomas, 2 adenosquamous carcinomas, and 2 double carcinomas). Clinicopathologic data (sex, age, stage, survival period, histologic type, and degree of cell differentiation) were evaluated using a statistical analysis system. PDGF reactivity was positive in tumor cell cytoplasm in some cases of squamous cell carcinoma (64%) and adenocarcinoma (55%) and in all cases of large-cell carcinoma, adenosquamous carcinoma, and double carcinoma. PDGF-R reactivity was detected only in tumor stroma. Positive PDGF staining was associated with a poor prognosis in patients with lung carcinoma, independent of age, sex, stage, and degree of cell differentiation (risk ratio = 2.53, p = 0.03). PDGF B mRNA was detected in 100% of PDGF-positive squamous cell carcinomas and in 85% of adenocarcinomas. There was no correlation between PDGF expression and PCNA index in lung carcinomas. Together, these results suggest that immunohistochemistry for PDGF B-chain may predict the outcome for lung carcinoma patients.

Fetal hamster lung explant was cultured in serum-free medium on gestational Day 11-2 days before the appearance of pulmonary neuroendocrine cells (PNEC)--and the development and differentiation of PNEC from immature fetal lung epithelium was examined through immunostaining for neural cell adhesion molecule (NCAM) to establish an in vitro system to study the mechanisms involved. PNEC were present in the main bronchus after 2 days of culture. Thereafter, NCAM-positive clusters of PNEC increased and were distributed from the large bronchus to the terminal bronchiole with a proximal-to-distal wave. To elucidate the role of NCAM in the fetal development of PNEC, whole fetal lung was cultured on gestational Day 11 with an anti-NCAM antibody. This antibody slightly inhibited the growth and branching morphogenesis of the lung and disturbed the formation of PNEC clusters. NCAM may function to form clusters of PNEC known as neuroepithelial bodies. We cultured fetal lung epithelial explant at gestational Day 11 after removing mesenchyme, including nerve tissue, with dispase digestion. Immunohistochemical staining for NCAM revealed that PNEC were induced in cultured fetal epithelium without mesenchymal tissue, but basement membrane Matrigel was necessary to maintain cultured epithelium. In conclusion, PNEC derive from immature airway epithelial cells. This organ culture system, therefore, is a useful experimental model and should facilitate further investigations of the development and differentiation of PNEC. Mesenchymal and neural tissues are not always necessary for the development of PNEC, but matrix substance and/or growth factors may be required to induce or maintain PNEC.

The cytoplasmic domain of integrin beta 4, which contains four type III fibronectin-like motifs, seems to be involved in the regulation of the assembly of hemidesmosomes (HD) and, therefore, in cell adhesion. An in-frame deletion of 17 amino acids in the second fibronectin type III repeat of integrin beta 4 (delta 17-beta 4) has been associated with junctional epidermolysis bullosa with pyloric atresia (PA-JEB), a genetic disease characterized by altered HD and disadhesion of the epidermis. To determine the effect of deletion delta 17-beta 4 on HD assembly, we have examined the expression and localization of the HD components in the skin and cultured keratinocytes of a patient with PA-JEB, which express the mutated integrin beta 4. Our results show that the mutated beta 4 subunit associates with integrin alpha 6, but the resulting heterodimer does not induce nucleation of the bullous pemphigoid antigens BP180 and BP230, and that of the inner plaque component plectin/HD1, into hemidesmosomal structures. The integrity of the cytoplasmic tail of integrin beta 4 seems to be essential to the targeting and stabilization of plectin/HD1 and BP180 in HD, because transfection of a recombinant wild-type B4 cDNA in the delta 17-beta 4 PA-JEB keratinocytes restores the synthesis of a functional alpha 6/beta 4 heterodimer, which promotes the polarization of plectin/HD1 and BP180, to the basal aspect of the cells. Because in the transfected keratinocytes the distribution of BP230 remains diffuse in the cytoplasm, we suggest that the interaction between plectin/HD1 and integrin alpha 6 beta 4, followed by the association with BP180, constitutes the first step in the nucleation of the HD.

Testis angiotensin-converting enzyme (testis ACE), an ACE isozyme that plays an important role in male fertility, is transcribed from a unique promotor active only in developing spermatids. In vitro analysis suggests the importance of a cyclic AMP response element (CRE)-like region within the testis ACE promoter, and similar DNA motifs are important in the expression of a variety of testis-specific genes. In the present study, we examined the effects of mutations in the CRE-like element on testis ACE promoter activity in vivo using transgenic mice. Disruption of this element reduced reporter gene expression to near background levels. In contrast, conversion of the CRE-like element to a consensus CRE-binding site resulted in high level expression of the reporter gene specifically in the testis. These experiments prove that the CRE-like element is essential for testis ACE promoter activity, although it does not appear to be responsible for its tissue specificity. These data provide insight into how a phenotypically differentiated tissue, ie, male gem cells, regulate tissue-specific gene expression.

Many patients with AIDS have a myelopathy characterized by vacuolization of spinal cord white matter. The biochemical and molecular changes underlying this myelin disturbance have not yet been characterized. Myelin basic protein (MBP) is potentially important because it is a key structural protein of myelin with roles in compaction and stabilization. In the present study, we describe the steady-state protein concentration of MBP in 46 patients with AIDS and 12 control subjects at autopsy. Patients with myelopathy exhibited no change in the abundance of the predominant 18.5- and 17.2-kd isoforms, but a 14-kd MBP-immunoreactive degradation fragment was increased significantly. MBP degradation correlated significantly with the severity of histopathologic changes, including neutral lipid deposition, the density of vacuolated fibers, and the number of ferritin-stained activated microglia. Alkaline gel electrophoresis of isolated MBP showed preferential loss of the least cationic isomer (C-8). The concentration of MBP RNA in slot blots was normal in cords exhibiting myelopathy, and the ratio of mRNA corresponding to the 18.5- and 17.2-kd MBP isoforms, measured using reverse transcriptase-PCR, was not altered. This study suggests that mononuclear phagocyte-mediated degradation of MBP may play a role in AIDS myelopathy, and the preferential loss of the C-8 component of MBP may have mechanistic implications.

Serum amyloid P component (SAP), a common component of all known types of amyloid fibrils, protects amyloid fibrils from proteolysis in vitro. It is therefore speculated to contribute to the deposition of amyloid fibrils in various types of amyloidoses. However, a role for SAP in amyloid deposition is not yet known. To investigate the relationship between SAP and amyloid deposition, we used gene targeting techniques to generate a unique strain of mice carrying a null mutation at the sap locus. The resultant SAP-deficient mice displayed no obvious phenotypic abnormalities. We asked whether experimental amyloid A (AA) amyloidosis could be induced in the SAP-deficient mice. The wild-type and SAP-deficient mice did not differ in their synthesis of serum amyloid A, the precursor protein of AA amyloid fibril, in response to acute inflammation. The induction of AA amyloidosis, however, was significantly retarded in the SAP-deficient mice relative to wild-type mice. Our experiments present, for the first time, compelling evidence that, although not essential in the deposition of AA amyloid, SAP significantly accelerates this reaction. Thus, SAP enhances the induction of murine amyloidosis and may play an important role in the pathogenesis of human amyloidoses, including Alzheimer's disease.