text
stringlengths 1
13.2k
|
---|
In this prospective study, we have compared women undergoing laparoscopic cholecystectomy, laparoscopic gynaecological surgery and laparoscopic minor gynaecological procedures (diagnostic, tubal, ligation) (n = 10 in each group) to determine if lower abdominal laparoscopy results in less postoperative pulmonary dysfunction than upper abdominal laparoscopy. Pulmonary testing was performed before operation, and 3 and 6 h after operation, on the first and second days after surgery. After operation, a significant reduction in forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow rate occurred after laparoscopic cholecystectomy at each time. There were no significant changes after minor gynaecologic laparoscopy, whereas laparoscopic gynaecological surgery resulted in minor pulmonary dysfunction on the day of surgery only. We conclude that postoperative pulmonary function was less impaired after gynaecological laparoscopy than after laparoscopic cholecystectomy. This study suggests that the site of surgery is an important determinant of lung dysfunction after laparoscopy. |
Ten male volunteers received a 1-min i.v. infusion of a new water soluble steroid anaesthetic agent, ORG 21465. Individuals received doses ranging from 0.8 to 1.8 mg kg-1. All subjects experienced venous pain at the site of injection; those receiving 1.0 mg kg-1 or more became anaesthetized. There was no evidence of histamine release and apnoea did not occur. Excitatory phenomena were observed in all subjects and were dose related; no spikes were seen on the EEG. Pharmacokinetic analysis supported a three-compartment (non-weight-related) model with compartmental volumes V1, V2 and V3 of 4.31, 14.2 and 89.4 litre, respectively. Clearance from the central compartment V1 was 1.55 litre min-1. Inter-compartmental clearances Q1 and Q2 were 2.54 and 1.79 litre min-1. We found that ORG 21465 was an effective anaesthetic in humans. The relationship between sedation, anaesthesia and excitation requires further exploration. |
ORG 21465 has been found to possess anaesthetic properties in humans and its pharmacokinetics are known. We performed this study to confirm the characteristics associated with its administration and to define its pharmacodynamic profile, in particular to explore the relationship between sedation, anaesthesia, excitation and plasma drug concentrations. A water soluble preparation of ORG 21465 was administered to six male volunteers as a series of three 15-min computer-controlled, pharmacokinetic model-driven infusions targeting three exponentially increasing plasma concentrations: 0.5, 1 and 2 micrograms ml-1. The clinical characteristics of the resultant sedation and anaesthesia were observed. Plasma concentrations of ORG 21465 were measured during and for 500 min after the infusions and the EEG recorded. A sigmoid e-max effect compartment pharmacodynamic model was fitted to the plasma concentrations and an EEG derivative (spectral edge frequency (SEF)). Anaesthesia with ORG 21465 was associated with involuntary movements in all subjects. A steady state concentration of 1180 ng ml-1 depressed SEF by 50%, the Hill factor describing the sigmoid nature of the concentration-response curve was 1.42 and the equilibration rate constant of the biophase was 0.112 min-1. Anaesthesia with ORG 21465 was found to be unsatisfactory because of involuntary movements and slow equilibration with the biophase. |
A retrospective review over 6 yr of patients presenting to the hand clinic was performed to identify cases of postoperative brachial plexopathy (PBP) and to assess both prognosis and early indices of prognosis. Over this period (1989-1995), 22 patients were referred by the hospital's surgical departments to the hand clinic because of PBP. Eight cases followed open heart surgery (OHS) and 14 followed non-cardiac surgery (NCS). Median full recovery took 10 (range 4-16) weeks and 20 (8-50) weeks, respectively. Long-term follow-up revealed one OHS patient with residual tingling and three NCS patients with residual weakness. Brachial plexopathy after median sternotomy was characterized by a predominance of sensory complaint in the lower roots of the plexus. Injury after non-cardiac surgery was reflected by a predominance of motor deficit in the upper and middle roots. Brachial plexus injury after cardiac surgery carries an excellent prognosis for full functional recovery. Although the limited number of cases precludes statistical substantiation, the data suggest that the prognosis of PBP after non-cardiac surgery may be worse in males, diabetics, those with injury to all roots of the plexus and, when in addition to the motor deficit there is sensory loss and pain or dysaesthesia. At a 1 week "prognostic milestone", 79% of NCS patients with significant symptomatology enjoyed complete recovery although this took as long as 5 months to 1 yr in 50% of patients. At a 6-8 week "prognostic milestone", 50% of those who had not yet had improvement in the motor deficit suffered residual neurological deficit. All patients recovered to a significant extent even when recovery was not complete and none suffered from late deterioration or chronic pain. |
We conducted a prospective, randomized, double-blind study to compare analgesia obtained by wound infiltration using 29 ml of 0.25% bupivacaine alone, or with the addition of clonidine hydrochloride 150 micrograms. A third group received bupivacaine wound infiltration with clonidine 150 micrograms i.m. to control for the systemic effects caused by absorption of clonidine. We studied 46 adults undergoing elective inguinal hernia repair. The general anaesthetic technique, postoperative analgesia and wound infiltration technique were standardized. There was no difference in time to first analgesic request or to total analgesic consumption between the three groups during the 24-h study. Visual analogue scores (VAS) at rest and after coughing were noted over a 24-h period. The only difference was higher VAS scores at rest at 24 h in the control group who received i.m. clonidine. We conclude that for elective inguinal hernia repair, postoperative analgesia obtained by bupivacaine wound infiltration was not improved by the addition of clonidine 150 micrograms. |
Sixteen patients undergoing coronary revascularization requiring cardiopulmonary bypass received remifentanil 2 micrograms kg-1 or 5 micrograms kg-1 by infusion over 1 min after sternotomy but before commencing cardiopulmonary bypass, during hypothermic cardiopulmonary bypass and during cardiopulmonary bypass after rewarming. Hypothermic cardiopulmonary bypass reduced the clearance of remifentanil by an average of 20%, and this was attributed to the effect of temperature on blood and tissue esterase activity. Reductions in arterial pressure occurred with administration of both doses during normothermia only. |
In a prospective, randomized study, we have investigated the effects of two arbitrary pulse oximeter lower alarm limit (LAL) settings (90% = group 90, n = 320 and 85% = group 85, n = 327) on the incidence of hypoxaemia in the recovery room. In group 90, we calculated the theoretical effect of elimination of transient episodes of low pulse oximeter oxyhaemoglobin saturation (SpO2) by introducing a time delay between the onset of the alarm condition and triggering of the alarm. When only hypoxaemic episodes lasting more than 1 min were included, SpO2 < or = 90% occurred in 11% of patients in group 90 and in 20% in group 85 (relative risk (RR) 1.84, confidence interval (CI) 1.26-2.69; P < 0.01). Hypoxaemia < or = 85% occurred in 2% of patients in group 90 and in 6% in group 85 (RR 3.10, CI 1.32-7.28; P < 0.01). In group 90, 1007 alarms (33% false) occurred, whereas in group 85, 395 alarms (28% false) occurred. Introducing a theoretical delay of 15 s in group 90 between crossing the alarm threshold and triggering the alarm would have reduced the number of alarms by 60%. The results of the study suggest that decreasing the alarm limit in an attempt to reduce frequent false alarms may lead to an increase in more relevant episodes of hypoxaemia and setting the LAL at 85% cannot be recommended routinely. Introducing a 15 s delay in group 90 would reduce the number of alarms by the same amount as changing the LAL from 90% to 85%. |
We have studied 64 ASA I and II patients (aged 20-60 yr) to determine if nitrous oxide affects sevoflurane requirement for achieving 50% probability of no movement in response to verbal commands (MACawake). Patients were allocated randomly to one of four nitrous oxide concentration groups (0, 20, 40 and 60 vol.%). Patients in each group received sevoflurane at two different end-tidal concentrations according to a predetermined randomization table. After steady state sevoflurane and nitrous oxide concentrations had been maintained for at least 15 min, patients were assessed as being awake or asleep. The MACawake for sevoflurane was 0.63% and this was reduced significantly in a non-linear manner by increasing nitrous oxide concentration. A 50% reduction in MACawake was produced by a nitrous oxide concentration of 45%. The reduction in MACawake by nitrous oxide was non-linear; the interaction coefficient between nitrous oxide and sevoflurane being significantly less than zero (P = 0.0238), indicating that the reduction in MACawake by nitrous oxide was smaller than would be expected from simple additivity and that nitrous oxide antagonized the effects of sevoflurane in preventing response to verbal commands. |
We have examined cerebral pressure autoregulation while awake, and during 0.5 and 1.5 MAC of sevoflurane anaesthesia in 10 patients undergoing non-intracranial neurosurgical procedures. All patients received a standardized anaesthetic comprising premedication with temazepam 20 mg orally, a sleep dose of propofol, fentanyl 1 microgram kg-1 and vecuronium 0.1 mg kg-1. After tracheal intubation, the lungs were ventilated with a mixture of air and oxygen to mild hypocapnia. Routine monitors included ECG, continuous and intermittent non-invasive arterial pressure, pulse oximetry and end-tidal capnography. In addition, blood flow velocity (vmca) was measured by insonating the middle cerebral artery transtemporally using a 2-MHz transcranial Doppler probe. Cerebral pressure autoregulation was tested by increasing mean arterial pressure (MAP) by approximately 20 mm Hg using an infusion of phenylephrine and simultaneously recording vmca. The index of autoregulation (IOR) during each period of the study, calculated as the ratio of percentage change in estimated cerebral vascular resistance (CVRe = MAP/vmca) to percentage change in MAP, was compared using ANOVA. vmca during 0.5 and 1.5 MAC of sevoflurane anaesthesia was significantly lower than that while awake (mean 79 (SD 24), 54 (15) and 51 (12) cm s-1, respectively; P < 0.05). There was no significant change in vmca with the increase in MAP while awake, or during 0.5 or 1.5 MAC of sevoflurane anaesthesia and IOR was similar under the three conditions (0.82 (0.11), 0.83 (0.04) and 1.0 (0.03), respectively). We conclude that cerebral pressure autoregulation remained intact during sevoflurane anaesthesia in humans. |
We have investigated the effects of two techniques of clinical anaesthesia on human respiratory cilia by measuring cilia beat frequency of nasal tissue. In a randomized, controlled study, 13 patients undergoing either inhalation anaesthesia with isoflurane or total i.v. anaesthesia with propofol and alfentanil had nasal ciliated epithelial samples removed at the beginning and after 1 h of anaesthesia. Mean cilia beat frequency in the group anaesthetized with isoflurane changed significantly from 11.5 (95% confidence interval (CI) 10.7-12.2) Hz to 9.1 (8.1-10.1) Hz after anaesthesia whereas in the group anaesthetized with propofol and alfentanil there was a change from 11.5 (10.7-12.2) Hz to 11.0 (10.2-11.8) Hz (ns). The difference between the anaesthetic agents on cilia beat frequency was significant (MANOVA, P < 0.01). These data suggest that different anaesthetic agents may impair respiratory defence mechanisms to differing extents. |
The inhibitory effects of nitroglycerin (NTG) on platelet function and the mechanisms of inhibition have been studied in vitro, but not in vivo. Therefore, we have investigated the effects of NTG on platelet function in eight patients undergoing orthopaedic surgery. Simultaneous measurements of platelet aggregation and change in intracellular calcium concentrations were performed in Fura-2 loaded platelets using thrombin as a stimulator. Intraplatelet concentrations of cyclic 3',5'-guanine monophosphate (cGMP) were measured by radioimmunoassay, and the concentration of nitrite ion was also measured. Continuous i.v. infusion of NTG 4-8 micrograms kg-1 min-1 significantly inhibited platelet aggregation and the increase in intracellular Ca2+ concentration (first phase, mean 439.9 (SEM 68.7) vs 210.6 (38.7) nmol litre-1; second phase, 154.4 (19.8) vs 106.7 (18.0) nmol litre-1). The concentration of cGMP (from 0.633 (0.098) to 1.764 (0.578) pmol/10(9) platelets) and the concentration of nitrite ion (from 532.6 (17.6) to 724.4 (34.8) nmol litre-1) also increased significantly after infusion of NTG. The NTG concentration in plasma was of the order of 10(-8) mol litre-1. We have demonstrated that in vivo, NTG increased intraplatelet cGMP concentrations and inhibited platelet function; one mechanisms of this effect is likely to be related to nitric oxide liberation from NTG bioconversion. |
Transoesophageal echocardiography is a sensitive monitor for intraoperative myocardial ischaemia. Colour kinesis is a new technology for echocardiographic assessment of regional wall motion based on acoustic quantification. We have examined the feasibility and accuracy of quantitative segmental analysis of colour kinesis images to provide objective evaluation of systolic regional wall motion during the perioperative period using transoesophageal echocardiography (TOE). Two-dimensional echocardiograms were obtained in the transgastric short-axis and long-axis views in 60 patients with coronary artery disease undergoing noncardiac surgery. End-systolic colour overlays superimposed on the grey scale images were obtained with colour kinesis to colour encode left ventricular endocardial motion throughout systole. These colour-encoded images were divided into segments and compared with corresponding conventional two-dimensional images. Six hundred of a potential 720 left ventricular wall segments were of sufficient resolution for grading by experts; they diagnosed wall motion abnormalities in 61 of these segments by a conventional method. In comparing the conventional TOE method with colour kinesis, there were 60 true positives, 482 true negatives, 57 false positives and 1 false negative result. This yielded a sensitivity of 98%, specificity of 89%, positive predictive value of 51% and negative predictive value of 100%. Translational and rotational movement of the heart and papillary muscle interference were common problems accounting for false positive diagnoses. We conclude that colour kinesis provides a basis for objective and on-line evaluation of left ventricular regional wall motion which is a sensitive but non-specific method. It may be a useful aid for the less experienced because it can potentially direct the anaesthetist's attention towards specific segments. |
We quantified the total variability (reproducibility) and the within-patient but between repeat anaesthetics variability (repeatability) in measures which are used to judge the predictive performance of our physiological model. We studied 14 patients who received enflurane closed-circuit anaesthesia on two occasions. The end-tidal concentrations measured and those predicted served to calculate the predictive performance measures of the model: root mean squared error (rmse = total error), bias (systematic error) and scatter (error around the bias). The overall results were: rmse 15 (7)%, bias 0 (14)% and scatter 9 (3)% (grand mean (total SD)). The within-patient SD values were smaller for the rmse (4%) and bias (10%), but not for scatter (3%). The repeat rmse values and biases were linked to the first results. This implies that these performance measures depended partly on the patient. As there was no association between the personal performance measures and age, sex, body weight, body surface area or body mass index, these characteristics cannot be used to further tune the model. |
We describe a six-compartment physiological model of the kinetics and dynamics of induction of anaesthesia with propofol in sheep. It includes a faithful description of initial bolus kinetics caused by accurate representations of the inter-relationships between initial vascular mixing, lung kinetics and cardiac output, the use of the brain as the target organ for propofol anaesthesia (two-compartment sub-model with slight membrane limitation), a description of the effects of propofol-induced changes in cerebral blood flow and a combined description of systemic kinetics as two tissue pools. Variables for the model were estimated from an extensive in vivo data set using hybrid modelling. Propofol was characterized by rapid transit through the lungs, but a slower transit time though the brain, leading to significant delay between arterial blood concentrations and cerebral effects. |
The determinants of induction of anaesthesia with propofol, and their implications for dose requirements, were analysed using a physiological model of the process, validated previously using sheep data. The maximum depth of anaesthesia occurred 2-3 min after cessation of injection. Injection over 2 min minimized the induction dose. More rapid injection (< 1 min) did not significantly hasten induction, but increased dose requirements and produced large peak arterial concentrations, potentially risking increased hypotension. Cardiac output and cerebral blood flow were important determinants of the induction process. Increased cardiac output decreased the duration of anaesthesia, while increased cerebral blood flow increased the depth but not duration of anaesthesia. The influence on dose requirements of propofol of factors such as anxiety, hyperventilation, age and co-induction with other drugs may be interpreted in terms of their effect on cardiac output and cerebral blood flow. |
We have investigated the influence of a cold water bolus (CWB) injection on overestimation of cardiac output (CO) in low CO states in anaesthetized dogs. CO was measured using three methods: (1) thermodilution (TD), (2) electromagnetic (EM) flow meter placed on the pulmonary artery and (3) transoesophageal echo-Doppler (OD) placed on the descending aorta. Measurements of CO were obtained before (steady state) and after induction of a low CO state with thiopentone 5 mg kg-1 i.v. After CWB injection, mean CO measured by EM and OD increased by 26% and 27%, respectively (P < 0.05) during steady state, and by 85% and 75% (P < 0.05) during the low CO state. This transient increase was produced by an increase in stroke volume, while heart rate did not change. Frank Starling's law may explain this variation by a sudden increase in preload produced by CWB injection. These results indicate that thermodilution overestimated CO during low CO states when CWB injection was used. |
We have investigated the effect of temperature on the blood-gas solubility of desflurane, sevoflurane, enflurane and halothane. Blood was equilibrated with gas mixtures of known composition in open cuvette or closed flask tonometers over a temperature range of 29-39 degrees C, and the concentration of each anaesthetic in blood was measured at 37 degrees C by repeated headspace analysis using a gas chromatograph. Solubility increased by 5.4% of the solubility at 37 degrees C for each degree that equilibration temperature was reduced. This result was true for all anaesthetics in all blood samples, and is in keeping with results for other volatile anaesthetics. |
We have examined the binding of the local anaesthetic agent [3H]amethocaine to rat cerebrocortical membranes. All studies were performed in Tris buffer 50 mmol litre-1 at pH 7.4. Bound and free radioligand were separated by rapid vacuum filtration. [3H]Amethocaine binding at room temperature was dose-dependent and saturable, with mean Kd and Bmax values of 153 (SEM 18) nmol litre-1 and 9.4 (1.6) pmol/mg protein, respectively. [3H]Amethocaine binding was displaced in a dose-dependent manner (pIC50) by unlabelled amethocaine (6.89), procaine (5.20), lignocaine (3.46) and prilocaine (2.81). Ropivacaine and bupivacaine did not produce 50% displacement at the highest concentrations used (10(-4) and 10(-3) mol litre-1, respectively). We examined the nature of the binding site further with a range of ion channel antagonists (nifedipine, verapamil, diltiazem, omega-conotoxin, tetrodotoxin, tetraethylammonium and 4-aminopyridine) and ion channel coupled receptor ligands (L-glutamate, MK801, GABA, glycine and nicotine). With the exception of tetraethylammonium (pIC50 3.07) and 4-aminopyridine (pIC50 3.68), all non-anaesthetic agents failed to displace [3H]amethocaine. Collectively our data suggest that it is unlikely that there is a single target site for all local anaesthetic agents. |
We have examined the effect of nitrous oxide on spontaneous sympathetic activity and A delta- and C-fibre mediated somatosympathetic reflexes in renal nerves, evoked by supramaximal electrical stimulation of radial nerves in anaesthetized, paralysed dogs undergoing mechanical ventilation. In six preparations, nitrous oxide was administered at end-tidal concentrations of 10%, 30%, 50% and 70%, each for 20 min. Spontaneous renal sympathetic activity increased significantly to 147.8% and 151.2% of control values with 50% and 70% nitrous oxide, respectively (P < 0.05), but there were no significant changes in A delta and C reflexes. We conclude that the large increase in spontaneous sympathetic activity was dissociated from somatosympathetic reflexes which remained unchanged at these concentrations of nitrous oxide. |
We studied the efficacy of granisetron, a selective 5-hydroxytryptamine type-3 receptor antagonist, in preventing postoperative nausea and vomiting (PONV) after middle ear surgery. In a randomized, double-blind, placebo-controlled study, 60 ASA I patients received placebo (saline) or granisetron 40 micrograms kg-1 i.v. immediately before induction of anaesthesia (n = 30 in each group). A standard general anaesthetic technique was used. During the first 24 h after anaesthesia, the incidence of PONV in patients who had received granisetron was lower than in those who had received placebo (17% vs 63%; P < 0.05). There were no clinically important adverse effects in either group. We conclude that granisetron, given before anaesthesia, reduced the incidence of PONV after middle ear surgery. |
We have compared the effects of pethidine, alfentanil and placebo in the treatment of post-anaesthetic shivering. Ninety patients who shivered after routine surgery were allocated randomly to receive normal saline (n = 30), alfentanil 250 micrograms (n = 30) or pethidine 25 mg (n = 30). After 10 min, 26 patients had stopped shivering in the pethidine group which was significantly more than the incidence in the two other groups (placebo = 7; alfentanil = 12) (P < 0.0002). Alfentanil was not significantly different from normal saline in affecting shivering. We conclude that alfentanil 250 micrograms was not effective in the treatment of post-anaesthetic shivering. |
The Bair Hugger system is a new and highly effective active patient warming system which produces a layer of warm air between the patient and the warming system. We report an instance of marked softening and distortion of a polyvinyl chloride tracheal tube caused by this layer. We also present laboratory data indicating that this is a likely problem under routine theatre conditions, with suggestions for prevention. |
BACKGROUND Penicillin skin testing has been limited by the lack of commercially available penicilloate and penilloate reagents. OBJECTIVE This project was proposed to produce a stable, well-characterized supply of penicilloate and penilloate for intrastate use by our health maintenance organization and to document clinical safety and efficacy. METHODS An improved method of extraction for penicilloate and penilloate, which changed the solvents used during recrystallization, was developed. With these newly prepared reagents, penicillin skin testing was performed on 348 subjects. Skin testing was immediately followed by an oral challenge of 250 mg of amoxicillin in 215 of 288 (75%) subjects displaying a negative response to a battery of penicillin skin tests. RESULTS Nuclear magnetic resonance and mass spectrometry of the newly produced penicilloate and penilloate showed no evidence of organic contamination. Penicillin skin testing resulted in 17.2% (60 of 348) positive test results, with 20% of the subjects with positive results only responding to the newly produced minor determinants. The rate of mild adverse reactions to penicillin skin testing was 1.1% (4 of 348). The rate of mild acute adverse reactions was 5.1% (11 of 215), and the delayed reaction rate was 0.9% (2 of 215) with the amoxicillin challenge. CONCLUSIONS This improved penicillin minor determinant extraction method allows for the reproducible production of very pure preparations of penicilloate and penilloate. Large-scale penicillin skin testing, followed by amoxicillin challenge if results are negative is feasible in a large group model health maintenance organization operating within a single state with the use of internally produced penicilloate and penilloate and commercially available penicillin, amoxicillin, and penicilloyl polylysine. |
BACKGROUND Many nasal corticosteroids with different potencies and formulations are available, but they have all been proven safe and effective. The clinical relevance, if any, of these differences is not yet completely established. OBJECTIVE We sought to compare the efficacy, safety, and patients' acceptance of triamcinolone acetonide aerosol spray and fluticasone propionate aqueous solution in the treatment of spring allergic rhinitis. METHODS After a drug-free baseline evaluation, patients with rhinitis were randomized to receive either a triamcinolone aerosol spray of 110 microg in each nostril once daily (n = 117) or a fluticasone solution spray of 100 microg in each nostril once daily (n = 116) in a single-blind, parallel-group study. The Rhinitis Index Score (sum of scores of symptoms on a scale from 0 to 3) was evaluated daily, in the morning before drug administration, for 21 days. The efficacy of each treatment was assessed by the mean reduction from baseline in the Rhinitis Index Score and in individual symptom scores. Patients' acceptance of the study drugs was also monitored by a daily questionnaire. RESULTS Reductions of the Rhinitis Index Score (mean +/- SEM) were 4.20 +/- 0.21 and 4.60 +/- 0.21 for triamcinolone and fluticasone, respectively (p = 0.23). There were no statistically significant differences between the drugs in the reduction of any of the individual symptoms. Patients expressed statistically significant differences between the drugs regarding acceptance; different properties of the aerosol and the solution were appreciated differently. CONCLUSIONS This study shows that triamcinolone acetonide aerosol and fluticasone propionate solution sprays are both clinically equally effective, safe, and well tolerated for the treatment of spring pollen allergic rhinitis. |
BACKGROUND The minimum dose of food protein to which subjects with food allergy have reacted in double-blind, placebo-controlled food challenges is between 50 and 100 mg. However, subjects with peanut allergy often report severe reactions after minimal contact with peanuts, even through intact skin. OBJECTIVE We sought to determine whether adults previously proven by challenge to be allergic to peanut react to very low doses of peanut protein. METHODS We used a randomized, double-blind, placebo-controlled food challenge of 14 subjects allergic to peanuts with doses of peanut ranging from 10 microg to 50 mg, administered in the form of a commercially available peanut flour. RESULTS One subject had a systemic reaction to 5 mg of peanut protein, and two subjects had mild objective reactions to 2 mg and 50 mg of peanut protein, respectively. Five subjects had mild subjective reactions (1 to 5 mg and 4 to 50 mg). All subjects with convincing objective reactions had short-lived subjective reactions to preceding doses, as low as 100 microg in two cases. Five subjects did not react to any dose up to 50 mg. CONCLUSION Even in a group of well-characterized, highly sensitive subjects with peanut allergy, the threshold dose of peanut protein varies. As little as 100 microg of peanut protein provokes symptoms in some subjects with peanut allergy. |
BACKGROUND There is a paucity of published data on the clinical presentation and the nature of the allergens involved in hypersensitivity to mollusks. This study reports the clinical and immunologic findings in 38 patients with reported immediate and delayed adverse reactions to abalone (Haliotis midae, Class Gastropoda). METHODS Patients were recruited as part of a South African seafood allergy survey. Allergic symptoms were assessed by a self-administered questionnaire. A total of 38 patients with abalone sensitivity were recruited. Specific IgE responses to abalone and other mollusks were studied by using RAST and inhibition ELISAs. Skin prick tests and lymphocyte proliferation assays were also performed on several of the subjects. Allergenic components of Haliotis midae were identified with Western blotting. RESULTS Twenty five of the 38 patients in the study were first seen with immediate symptoms, and 13 had delayed reactions. Seventeen of the sera tested were RAST positive. Skin prick tests responses with abalone extract were positive in all subjects with positive RAST responses (n = 8) and in 6 of 13 subjects with negative RAST responses. Five of the subjects with positive RAST responses had positive results on Western blotting and demonstrated binding to two major allergens with molecular weights of 38 and 49 kd. The 49 kd IgE-binding protein has been designated as Hal-m-1. CONCLUSIONS Abalone allergens are heat-stable proteins with molecular weights of 38 and 49 kd, later designated as Hal-m-1 according to International Union of Immunological Societies allergen nomenclature regulation. Our studies indicate a clear clinical and immunologic heterogeneity in patients reactive to abalone. |
BACKGROUND Available methods for the measurement of airborne laboratory animal allergens are not standardized and are often insufficiently sensitive for measurements in laboratories or in undisturbed animal rooms. Although low, the levels may be clinically relevant, because many scientists not involved in cleaning out cages or handling animals have rodent allergies. OBJECTIVE The purpose of this study was to develop a sensitive monoclonal assay to determine airborne rat allergen and test it in the evaluation of a sliding curtain system installed in refurbished rat rooms, with perforated, transparent polycarbonate screens, behind which were the cage racks. METHODS Monoclonal antibodies were produced against male rat urine by immunization in mice and fusion with mouse cell line Sp2/0. A novel biotinylated phenol compound was synthesized for immunoassay signal amplification in conjunction with horseradish peroxidase. Air filter samples were collected at a rate of 2 L/min, and allergen content in the filter eluates was determined. RESULTS Two monoclonal antibodies were produced and used in a sandwich ELISA, which bound alpha2u-globulin (Rat n 1.02). The assay detection limit was 3.2 pg/ml, about tenfold increased sensitivity compared with the unamplified assay. Allergen levels were lower in rooms when curtains were closed (median, 0.2 ng/m3) than behind the curtains (0.9 ng/m3, p = 0.01) or if the curtains were open (0.9 ng/m3, p = 0.001). However, allergen levels during cage cleaning, when curtains were drawn apart, were high (18 ng/m3). CONCLUSION We have developed a method for measurement of airborne rat allergen that can be standardized, measures an important allergen, and is sufficiently sensitive to measure low allergen levels with personal samplers. |
BACKGROUND Birch tree pollen allergens are an important cause of early spring hay fever and allergic asthma. Pollen counts provide a guide for individuals with birch pollen allergy. However, birch pollen, because of its size, has a low probability of entering the lower airways to trigger asthma. Yet birch pollen allergens are known to be associated with respirable particles present in the atmosphere. OBJECTIVE We sought to determine the concentration of major allergen Bet v 1 in birch pollen and respirable particles in the atmosphere during the birch pollen season. METHODS We used a two-site monoclonal antibody-based assay (ELISA) to quantitate Bet v 1 in pollen extracts and high-volume air sampler filters collecting particles larger and smaller than 7.2 microm. RESULTS Bet v 1 (0.006 ng) is detectable per birch pollen grain, of which 0.004 ng is present in aqueous extracts (13.9% of soluble proteins). Atmospheric Bet v 1 concentrations are correlated with birch pollen counts. Heavy rainfall tended to wash out pollen and particles, indicated by a mean daily Bet v 1 concentration of 0.12 ng/m3 (20 pollen equivalents), but light rainfall produced a dramatic increase in allergen-loaded respirable particles with Bet v 1 concentrations of 1.2 ng/m3 (200 pollen equivalents). CONCLUSION These results highlight the different environmental risk factors for hay fever and allergic asthma in patients sensitized to Bet v 1. Light rainfall causes an increase in respirable particles; hence, this is an important risk factor for asthma. |
BACKGROUND Allergic asthma is increasing in black South Africans, a cohort with inherently high basal IgE levels. Atopy has been linked to an excess of the T helper 2 cytokines IL-4 and IL-5 relative to the T helper 1 cytokine interferon-gamma (IFN-gamma); however, most studies have utilized T cell clones. Studies on peripheral blood mononuclear cells (PBMC) have shown decreased IFN-gamma release in patients with atopic dermatitis. It is uncertain whether this finding extends to atopic asthma. OBJECTIVES To characterize cytokine release by mitogen-activated PBMC from Xhosa children and to investigate whether reduced IFN-gamma release is a feature of atopic asthma and whether there is a relationship between cytokine profiles and asthma severity. METHODS Cytokine release and proliferation of phytohemagglutinin-stimulated PBMC from 10 patients with severe asthma and 14 patients with moderate asthma (highly allergic to house dust mites) and 17 healthy controls was assessed. Total serum, allergen-specific, and Ascaris-specific IgE was measured. RESULTS Proliferation did not differ between the groups. The release of IFN-gamma was progressively decreased (and the IL-4/IFN-gamma ratio increased) in the groups with moderate or severe asthma. Tumor necrosis factor-alpha release was reduced, but IL-4, IL-5, and granulocyte-macrophage-colony stimulating factor release was unchanged. The presence of Ascaris-specific IgE did not influence the cytokine profiles. CONCLUSION Our study extends the findings observed for other atopic disorders and suggests that defective IFN-gamma release is a generalized feature of atopic diseases. This study-the first to investigate both severe and moderate asthma, with the groups having similar atopic profiles-indicates that the extent of the defect in IFN-gamma release might be related to asthma severity. |
BACKGROUND In allergic subjects with asthma, the migration of CD4+ T cells to the lungs in the hours after allergen exposure may contribute to allergic inflammation in the target organ. OBJECTIVE We studied allergen-specific T cells from the peripheral blood and lungs of allergic subjects with asthma at baseline and after allergen challenge. METHODS In each patient, blood samples were taken 10 minutes before and 24 hours after the inhalation of a major sensitizing allergen. In vitro proliferation of peripheral blood CD4+ T cells specific for the same allergen used in the in vivo challenge was assessed. In one patient two Dermatophagoides pteronyssinus-specific T-cell clones (TCCs) were derived from peripheral blood, and their T-cell receptors were sequenced to determine their clonotypic determinants on the beta chains. The T-cell receptor determinants of the allergen-specific TCCs were sought in blood and bronchoalveolar lavage samples taken from this patient. RESULTS We found that allergen inhalation is followed by a decrement in the specific proliferation of peripheral CD4+ T cells to the same allergen used for bronchial provocation. In one patient the clonotypic determinants of two allergen-specific TCCs diminished in the peripheral blood, whereas they were simultaneously expanded in the lower respiratory tract. CONCLUSION Our data suggest that allergen-specific T cells are recruited from the peripheral blood to the bronchial lumen after allergen challenge. |
BACKGROUND There are four species of fire ants found in the United States in addition to the most common, Solenopsis invicta. Reactions have been reported from stings of each of these species, but large numbers of insects and adequate amounts of venom for study are very difficult to obtain. METHODS Venom was obtained, the purified allergens were isolated, and the complete amino acid sequences were determined for two of the three allergens from S. richteri. Skin testing and RAST studies were performed on patients with reactions to native fire ant stings and analyzed in comparison with clinical history. RESULTS The structures of S. richteri allergens have a high degree of similarity to S. invicta allergens. The Sol 2 allergens are less related to each other than either the Sol 1 (phospholipase AB) or Sol 3 (antigen 5) allergens. Patients sensitized to native species of fire ants react primarily to the Sol 1 and Sol 3 allergens, whereas those originally sensitized to S. invicta also react significantly to the Sol 2 and Sol 4 allergens. Some patients are initially sensitized to S. invicta and have life-threatening reactions to stings of native species. The tropical fire ant, S. geminata, has become a serious problem in some areas of the Pacific and South Asia, especially Okinawa and Guam. CONCLUSIONS The venoms from all of the species of fire ants examined appear to be highly cross-reactive. S. invicta imported fire ant venom extracts are probably sufficient for diagnosis and may warrant a clinical trial for immunotherapy of allergic reactions to venoms of any of the other four species. |
BACKGROUND Recent studies have caused much controversy about the prevalence of IgE antibodies to Hev b 1 among health care workers (HCWs) and patients with spina bifida (SB) who are allergic to latex. This investigation was carried out to verify the results reported. METHOD Serum samples from 140 patients with SB as well as from 105 HCWs allergic to latex were tested by enzyme allergosorbest test (EAST) and EAST-inhibition assay to evaluate the rate and degree of sensitization to highly purified Hev b 1. RESULTS Eighty-one percent of patients with SB who were allergic to latex had IgE antibodies against Hev b 1. The prevalence of anti-Hev b 1 antibodies among HCWs allergic to latex was 52.3%. In 15 of 33 serum samples from patients with SB that were randomly tested, the IgE binding to commercial latex allergens could be completely inhibited by Hev b 1; in only six cases was the maximum inhibition of IgE binding to latex by Hev b 1 less than 50%. Testing two monoclonal anti-Hev b 1 antibodies with extracts of five brands of latex gloves revealed a predominant presence of Hev b 1 protein as a monomer or its aggregates. Molecular analysis of human leukocyte antigen-D region genes DRB and DQB1 suggested no statistically significant correlation between the human leukocyte antigen alleles tested and IgE responsiveness to Hev b 1. CONCLUSIONS Our results indicate that Hev b 1 not only makes significant contributions to the IgE binding to latex, but it is also the unique sensitizer in about 45% of patients with SB who are allergic to latex. |
Atopic dermatitis (AD) is a chronic skin disorder, characterized by infiltration of activated memory CD4+ T cells into skin. A model to study the onset of allergic inflammation in a patient with AD is the atopy patch test (APT), in which, by epicutaneous application of aeroallergen, an eczematous reaction is induced in 50% of sensitized patients with AD. Extravasation of T cells into skin is thought to be critically dependent on expression of the surface molecule cutaneous lymphocyte-associated antigen (CLA), which recognizes and binds its ligand E-selectin on endothelium. We studied the dynamics of expression of CLA and the gut homing receptor alphaE beta7 (HML-1) on T cells in the skin of patients with AD and in APT reactions and nickel and sodium lauryl sulfate patch test reactions by means of immunohistochemical double staining of skin biopsy specimens. The results show an increase in the number of CD3+ T cells in the lesional skin of patients with AD, APT reactions, and nickel and sodium lauryl sulfate patch test reactions as compared with nonlesional skin of the same patients and nonatopic individuals. In contrast, the percentages of CLA+ T cells in the lesional skin of patients with AD, in the APT reactions, and in sodium lauryl sulfate and nickel patch test reactions were decreased. In addition, we found a marked expression of alphaE beta7 by T cells present in skin, indicating a nonspecific influx of T cells during allergic skin inflammation. We propose that during allergic skin inflammation CLA expression is not a prerequisite for cutaneous T-cell infiltration. CLA expression may be important for T cells to extravasate from blood into skin during immune surveillance or for retention of allergen-specific T cells in skin. |
BACKGROUND X-linked agammaglobulinemia is typically a severe life-threatening disease characterized by the failure of B-cell differentiation and antibody production, which manifests in infancy and early childhood. Recently, we reported a novel mutation (Cys145-->STOP) in Bruton's tyrosine kinase in a 51-year-old man who was referred for evaluation because of chronic nasal congestion, recurrent sinusitis, sporadic pneumonia, and a family history suggestive of an X-linked immunodeficiency disease. He had not been treated with gammaglobulin. OBJECTIVE This study was performed to investigate the clinical and immunologic phenotypes of this patient's other affected male family members. METHODS A detailed family history and comprehensive review of medical records was carried out. Genetic mutation analysis of the gene encoding Bruton's tyrosine kinase was carried out in the proband's brother and nephew. RESULTS Clinically affected male family members exhibit marked phenotypic variation with manifestations ranging from extremely mild to severe recurrent infections. Immunologic evaluation revealed extreme variation in immunoglobulin levels, B-cell numbers, and functional antibody titers. Genetic analysis documented a novel mutation in the gene encoding Bruton's tyrosine kinase in the proband, his brother, and his nephew. CONCLUSIONS Despite their sharing the same genetic abnormality, extreme variation was noted in the immunologic findings and phenotypic expression of affected family members. This family study is extraordinary in that clinically affected male members who did not receive aggressive medical treatment died of the disease in childhood or survived into late adulthood. |
Recent advances in our understanding of the pathogenesis of human immunodeficiency virus (HIV) disease and the important role that viral load plays in the initial selection of antiretroviral therapy significantly alters our management of this disease. Guidelines from the British HIV Association, International AIDS Society-USA, and United States Public Health Service panels regarding the selection of appropriate antiretroviral therapy, and from the Centers for Disease Control and Prevention on prophylaxis for opportunistic infections, have recently been published. Despite tremendous advances in treating the disease and its related complications, a comprehensive, long-term disease management plan that includes recognition of patient concerns about quality of life is lacking. New approaches to managing HIV disease must now include strategies that address patient concerns about fatigue, gastrointestinal distress, malnutrition, and weight loss. Patients must become more involved in decisions about selection of specific drugs and drug regimens and must be consulted about their expectations and needs. We have made significant strides in the treatment of HIV disease. We can readily reduce the viral burden to virtually undetectable levels, and we must continue to develop even more potent and tolerable treatment regimens. We can make patients live longer. Helping patients live better quality lives deserves further study. |
A number of virologic and immunologic markers, including serum human immunodeficiency virus (HIV)-1 p24 antigen levels, quantitative HIV-1 microculture of plasma or peripheral blood mononuclear cells, and CD4 cell counts, have been used over the past decade to monitor progression of HIV infection. Although these markers are useful, they have not provided a reliable means of assessing prognosis at all stages of the disease or response to antiretroviral treatment. New molecular techniques are now available that measure viral load in HIV-infected patients by detecting and quantifying virion-associated RNA circulating in plasma. These plasma HIV-1 RNA levels appear to correlate with the clinical disease stage and reflect the response to antiretroviral treatment. Because recent studies have demonstrated that baseline plasma HIV-1 RNA levels and changes in these levels are predictive of clinical outcome, it is strongly recommended that these markers be measured routinely and used as a guide in the management of all patients with HIV disease. |
Patients with advanced human immunodeficiency virus (HIV) infection who are severely immunosuppressed develop a variety of opportunistic infections that have a significant impact on their well-being, quality of life, health-care costs, and survival. The risk for development of opportunistic infections depends on exposure to potential pathogens, the virulence of the pathogens, the degree of host immunity, and the use of antimicrobial prophylaxis. Many studies have confirmed the benefits of prophylaxis in severely immunosuppressed patients. Factors that affect the use of prophylaxis for prevention of opportunistic infections in HIV-infected patients include the prevalence and potential severity of the disease, ease of treatment if infection occurs, the cost-effectiveness of the prophylactic regimen, and the potential for increased survival, drug toxicity, drug interactions, and emergence of resistance with the regimen. The United States Public Health Service and the Infectious Diseases Society of America (USPHS/IDSA) have established disease-specific recommendations for use of prophylaxis for opportunistic infections in HIV-infected patients. These guidelines identify regimens that are strongly recommended as standards of care, regimens that should be seriously considered in selected patients, and regimens that are not routinely indicated but may be considered in selected patients. Although further study is needed, advances in antiretroviral therapy may have an important impact on the recommendations for prophylaxis and may eventually allow discontinuation of these regimens in patients who regain functional immunity. |
Multilineage hematopoietic defects occur in patients with human immunodeficiency virus (HIV) infection and affect therapy of the disease and of associated opportunistic infections and neoplasms. Anemia and neutropenia are common in HIV patients, and can occur as a result of HIV-related myelosuppression or complications or may be secondary effects of antiretroviral or other agents used in management of the disease. With the advent of combination drug therapy for the treatment of HIV infection and prophylaxis and treatment of infectious complications, myelosuppression is frequently encountered and may be treated with synthetic hematopoietic growth factors. Erythropoietin has been shown to increase mean hematocrit levels and to reduce transfusion requirements in anemic HIV-infected patients receiving zidovudine. Granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor have been shown to increase neutrophil counts in patients with AIDS-related bone marrow failure and those receiving zidovudine, interferon-alpha, or ganciclovir. Although recent research using interleukin-2 (IL-2) has shown that use of this cytokine in AIDS patients can lead to increases in CD4 cell counts that appear to be functional, further study is needed to determine whether cytokines can play a role other than palliation in HIV-infected patients. |
Malnutrition is common in human immunodeficiency virus (HIV) infection and plays an important role in morbidity and mortality. Malnutrition can affect hospitalizations, disease complications, quality of life, and survival, and has adverse clinical consequences that may be independent of CD4 lymphocyte count. There have been recent advances in knowledge concerning the pathogenesis of malnutrition and the nature of weight loss in HIV patients. The onset of body cell mass depletion may occur early in the infection and predate significant immune deficiency, implying that the virus itself may be involved. Hypogonadism, a common finding in HIV patients, is associated with body composition changes and is involved in body cell mass depletion. In addition, intestinal dysfunction and malabsorption contribute to weight loss in HIV patients. Several studies have evaluated the use of appetite stimulants, enteral and parenteral nutritional support, anabolic agents, and other agents in the management of weight loss and malnutrition in HIV patients. Results of a randomized trial comparing total parenteral nutrition (TPN) and an oral semi-elemental diet (SED) in AIDS patients with malabsorption indicate that the TPN group consumed more calories and gained more weight than the SED group, but the gain was due to increased body fat. The effect of nutritional support on malnutrition and weight loss in HIV patients and potential secondary benefits to quality of life, physical and mental performance, immune function, and disease progression require further study. |
Advances in the management of human immunodeficiency virus (HIV) disease, including the use of potent combination antiretroviral regimens, has greatly improved the outlook for patients with AIDS. Because HIV patients can now survive for extended periods, clinicians need to develop rational plans for long-term therapy that recognize the impact of such therapy on the patient. There are many similarities between cancer and HIV disease and an oncologic model can be used to design treatment plans for HIV. A successful plan for long-term management of HIV involves establishing the diagnosis and extent of disease; determining the concerns of the patient as they relate to specific life goals and quality-of-life issues; identifying antiretroviral regimens for initial therapy, salvage therapy, and terminal or experimental therapy; and implementing the plan using clear parameters to evaluate the response to therapy. Tremendous strides have been made in managing HIV disease. It is now time to advance our management of the patients' concerns. |
Crystallographic studies suggest a plausible divalent interaction between T-cell receptor (TCR) and MHC class II molecules. In addition, biochemical data suggest that these divalent MHC molecules are preformed at the membrane of the antigen-presenting cell. The tetramer model is based on these preformed tetrameric class II molecules that can be loaded with identical or different peptides in their two grooves. This enables divalent class II molecules to deliver two different messages to T cell: 1) a two-peptide message, in which the tetramer with two identical peptides is able to cross-link two TCRs triggering full activation of a T cell. At the thymic level we propose that this message induces negative selection; or 2) a one-peptide message: only one of the peptides loaded in the class II tetramer is able to interact with that TCR. This message would be involved in triggering partial activation phenomena in mature lymphocytes, whereas in thymocytes this message would mediate positive selection. Since high concentrations of a peptide would favor the load of tetramers with identical peptides, the tetramer could therefore be viewed as a quantitative-qualitative transducer that would trigger different responses depending on the concentration of antigenic peptides. |
Endothelial cells express a wide spectrum of surface molecules involved in multiple vascular functions. We quantitatively determined an extensive immunologic phenotype of endothelial cells through a large panel of antibodies directed against i) well-known endothelial molecules CD31, CD34, CD49b, e, f, CD51, CD54, CD55, CD62E and P, CD105, CD106, HLA class I and HLA class II; ii) molecules defined by monoclonal antibodies newly clustered during the 6th workshop of Human Leukocyte Differentiation Antigen (HLDA) CD109, CD140b, CD141, CD142, CD143, CD144, CDw145, CD146 and CD147; iii) molecules defined by unclustered monoclonal antibodies. The expression of these molecules was quantified on human umbilical vein endothelial cells (HUVEC) cultured in resting conditions and after stimulation with IL-1beta (10 U/ml), TNF-alpha (10 ng/ml) and phorbol myristate acetate (60 ng/ml). Some molecules were constitutively expressed, and others were negative, which served to determine the basal phenotype. After cell stimulation, the molecules showed weak or strong expression modulation, leading to the definition of an activated phenotype. Changes in the kinetics and the amplitude of expression served to characterize poorly defined molecules and may be useful to determine their physiologic role. Also, we compared the phenotypes of endothelial cell lines EA.hy 926 and ECV 304 to that of HUVEC to assess their reliability as an endothelial cell model. Each cell line displayed a specific repertoire of molecules expressed at different levels, which could have significant implications for cell line behavior as endothelial cells. |
The number of HLA class I molecules and the susceptibility to lysis mediated by natural killer (NK) cells were evaluated on cell targets obtained from confluent and sparsely plated cultures of both normal and tumor cell lines. Sparsely plated proliferating cells expressed high amounts of HLA class I molecules and were more resistant to NK cell-mediated lysis than confluent cells, which expressed low amounts of HLA class I antigens. This characteristic could be involved in the control of cancer progression and could also explain the wide variability of assays of lymphocyte-mediated cytotoxic activity. |
The immune phenotype of canine hematopoietic progenitor cells was studied by immunoseparation and culturing of separated cells. Two separation methods were used, the magnetic cell sorting system (MACS) and the fluorescence activated cell sorter (FACS). For separation rat anti dog antibodies Dog 13 and Dog 14 directed against Thy-1, and Dog 26 as well as cross-reactive mouse anti human antibodies IOT2a and 7.2 directed against MHC class II were used. Separated cell populations were cultured in semisolid agar before and after long-term culture on a pre-established irradiated stromal cell layer. After 28 days, adherent and nonadherent cells were harvested from long-term culture. The MACS system allowed separation of cells into positive and negative fractions. Long-term culture-initiating cells (LTC-IC) were found in both the Thy-1+ and the Thy-1- fraction, but the content of LTC-IC was higher in the Thy-1+ fraction. The MACS system did not allow separation of progenitor cells according to the expression of MHC class II antigen detected by Dog 26 and the cross-reactive antibodies IOT2a and 7.2. In contrast to the MACS system the FACS allowed separation of negative, low-positive and high-positive cell populations. Low-positive fractions were well defined for Thy-1 and less well defined for MHC class II. CFU before and after long-term culture were exclusively observed in the low positive fraction (Thy-1(lo+)). Using MHC class II antibody Dog 26 LTC-IC were found mainly in the negative and low positive fraction, and CFU were observed mainly in the low and high positive fraction. In conclusion pluripotent canine hematopoietic precursor cells are low positive for Thy-1 and for MHC class II. In this respect canine hematopoietic progenitor cells are comparable to those of mouse and man. |
We hypothesize that kidneys from non-secretor blood group A2 donors may be used for transplant into non-A recipients. In addition, we believe that organs from A2 donors may be used in non-A recipients where the anti-A titer is low. In order to reliably identify non-secretor A2 kidneys from cadaver donors, we have developed a rapid molecular method. The PCR-SSP-based method was developed to genotype ABO blood group and secretor status. Samples of known blood group ABO and Lewis phenotype determined by standard serological methods were used to appraise the method. A retrospective renal cadaver donor study was conducted to assess the potential of using A2 non-secretor organs for transplantation into non-A recipients. Phenotype frequencies of blood group A donors were 76% and 24% for A1 and A2 subgroups respectively, whereas 27% of the donor sample population were non-secretors. Three donors were identified as A2 non-secretors, and analysis was performed to theoretically place the organs by considering them as blood group O. These results coupled with a detailed analysis of HLA type and antibody status of our panel suggests that using A2 donors would be a useful adjunct to strategies for transplanting highly sensitized patients and redressing the donor-recipient imbalance in terms of blood group. |
Plasma levels of tumor necrosis factor (TNF) alpha are raised during acute rejection following organ transplantation. Variations in TNF alpha production have been found to be associated with the polymorphism of TNF microsatellite. Therefore, there is a possibility that a transplant recipient with some type of TNF microsatellite can be a high-risk patient of graft rejection. The purpose of this study was to examine whether TNF microsatellite polymorphism is related to acute allograft rejection. We investigated the relation of two microsatellites, TNFa and TNFd, to acute rejection after renal transplantation. Among 189 primary living-related renal transplantations from one haplotype-mismatched and one DRB1-mismatched donor, we analyzed TNF microsatellites of 163 patients whose DNA were available to this study. The frequency of the TNFa9 microsatellite allele was significantly higher in the rejection group compared to the rejection-free group. In contrast, the frequency of TNFd4 was significantly lower in the rejection group compared to the rejection-free group. TNFa9 and TNFd4 showed strong associations with HLA-B35 and B44, respectively. However, the TNF microsatellite locus was more closely related to acute rejection than HLA-B. It was suggested that the analysis of TNF microsatellite polymorphism can provide useful information in predicting prognosis after transplantation. |
Okinawan Japanese are well known for their longevity; the population rate of centenarians in Okinawa is about 3.8 times higher than that of the whole Japan, where the average life expectancies both among men and among women are the highest in the world. In this study, we analyzed HLA class II alleles of Okinawan centenarians by the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method for the purpose of clarifying the presence of primary genetic factors in the major histocompatibility complex (MHC) region associated with human longevity. DRB1*1401, DQB1*0503, DQA1*0101=0104 and DQA1*05 were significantly increased in the centenarians. The significant increase of HLA-DQB1*0503 and/or DQA1*0101=0104 in the centenarians can be explained by a linkage disequilibrium with DRB1*1401, or vice versa. Further, the tendency was observed toward increase with respect to DRB1*0101 and DRB1*1201. These data suggest that several alleles of the HLA-DRB1 and/or HLA-DQ genes are involved in human longevity. |
Several different lines of evidence have demonstrated that inherited susceptibility to rheumatoid arthritis (RA) is associated with the DRB1 genes encoding the HLA-DR4 and HLA-DR1 molecules. A contrasting hypothesis has recently been proposed, suggesting that, in general, the DRB1 locus is associated with protection to RA and that the RA-associated DRB1 alleles are not responsible for the primary disease association but merely permissive for the susceptibility conferred by the HLA-DQ alleles with which they are in linkage disequilibrium. We have performed a critical review of the literature on the HLA association in RA with special emphasis on studies in which both an HLA-DR and -DQ association has been investigated. Our analyses provide strong evidence against the hypothesis that HLA-DQ molecules play a major role in the general susceptibility to RA. Thus, the strongest association in rheumatoid arthritis is with DRB1 genes rather than DQB1 genes. |
Selective immunoglobulin A (IgA) deficiency, the most common form of primary immunodeficiency, is related to the HLA genes. Previous studies demonstrated associations with particular HLA-DR-DQ haplotypes and a neutral amino acid at position 57 of the DQbeta chain was implicated in the susceptibility to selective IgA deficiency. In this study we reanalyzed the reported findings by high-resolution DNA typing of the loci DRB1, DQB1 and DQA1. We compared the typing results of 74 IgA-deficient individuals, detected by screening of blood donors, with those taken from 111 healthy controls. Results confirmed a strong positive association with DRB1*0301, DQB1*02 and a negative association with DRB1*1501, DQB1*0602. Considering the molecular interactions between HLA class II alleles and the peptides bound we conclude that the amino acid at position 57 of the DQbeta chain may contribute to the susceptibility to selective IgA deficiency, but not determine it. An extended statistical analysis strengthened the hypothesis that selective IgA deficiency might be communicated by the distinct haplotype DRB1*0301, DQB1*02. |
Allele frequencies for HLA-A, B and F and 15 microsatellite markers located from 100 kb telomeric to HLA-A to 6 Mb telomeric have been determined in a group of 60 blood donors. Linkage disequilibrium analysis revealed significant haplotype associations even after correction for the number of comparisons made. The HLA-A1, B8 haplotype extends as far as D6S276 (6.0 Mb telomeric to HLA-A). It is important to realize that this common haplotype extends beyond the HLA region, especially when evaluating haplotype associations with particular disorders. |
We have established a practical method of complete high-resolution typing for all HLA-A alleles using the polymerase chain reaction (PCR)-restriction fragment-length polymorphism (RFLP) technique combined with allele group- and sequence-specific amplification. The second and third exons of the HLA-A gene, in which most allelic variations are observed, were separately amplified by PCRs with 3 and 4 group-specific primer pairs, respectively. Each PCR-amplified product was digested by allele-specific restriction endonucleases and then subjected to electrophoresis on a 10% polyacrylamide gel. In this way, 62 out of 79 HLA-A alleles could be discriminated by the RFLP patterns derived from the genetic polymorphism in the exon 2 and 3 domains. The remaining 17 alleles could be defined unequivocally by either PCR-RFLP analysis after exon 4 amplification or PCR analysis with sequence-specific primers (SSP). By this method, complete HELA-A genotyping for all homozygous and heterozygous combinations can be accomplished, establishing technically simple, economical and practical routine typing of the HLA-A gene, especially for small samples. |
HLA class II DRB1-DQA1-DQB1 haplotypic polymorphism was determined in 120 Liberian and 230 Gabonese individuals. In our study groups, the number of allelic variants observed for each locus was similar to that found in non-African populations. However, 39 novel haplotypes and several yet unrecognized DRB1-DQA1 and DQA1-DQB1 combinations were identified. The extent of HLA-haplotypic variability in Africans appears to result from the high degree of allele combinations rather than from allelic polymorphism. |
A new DRB3*02 allele (DRB3*0207) was detected in a female Luxembourg Caucasian blood donor by sequence-based typing. The new allele differs from DRB3*0202 by two substitutions in codon 57 resulting in an amino acid change from a charged aspartic acid to a neutral valine. This is the first example of a DRB3 allele pair differing only at codon 57. |
A rapid profiling and screening procedure is described for the comparative analysis of urinary organic acids among the groups of nonsmokers and smokers. The procedure involves solid-phase extraction of organic acids using Chromosorb P in normal-phase partition mode, with subsequent single-step conversion to tert.-butyldimethylsilyl derivatives, followed by direct gas chromatographic (GC) analysis on dual-capillary columns. A total of forty-two organic acids were positively identified by retention index (I) matching in urine samples (0.25 ml) from eleven nonsmokers and fifteen smokers studied. When the GC profiles were simplified to their corresponding organic acid I spectra in bar graphical form, characteristic patterns were obtained for each individual as well as for each average of nonsmoking and smoking groups. When stepwise discriminant analysis was performed on GC data after omitting hippuric acid, seven acids were selected as the variables most discriminating between smokers and nonsmokers. The star symbol plots drawn based on these discriminants were characteristic of each individual and group average, enabling to distinguish smokers from nonsmokers. And canonical plot produced by canonical discriminant analysis using the same variables as the data vectors displayed two separate clusters representing each group. |
A sarin-like organophosphorus agent, [bis(isopropyl methyl)phosphonate; BIMP], was synthesized. This agent has the same phosphonate group as sarin and also has the same anti-acetylcholinesterase activity potency as sarin. The ID50 and LD50 values of BIMP in mice after intravenous injection were 3.9 nM and 0.8 mg/kg, respectively. The AChE activities of their red blood cells and brains were dose-dependently reduced by intravenous BIMP. After preparation of experimental BIMP-exposed human red blood cells, BIMP-bound acetylcholinesterase (AChE) was solubilized from erythrocyte membranes, purified by immunoaffinity chromatography, digested with trypsin, and the sarin hydrolysis products bound to AChE were released by alkaline phosphatase digestion. The digested sarin hydrolysis products were subjected to trimethylsilyl (TMS) derivatization and detected by gas chromatography-mass spectrometry. Isopropyl methylphosphonic- and methylphosphonic acids, which are the sarin hydrolysis products, were detected in experimental BIMP-exposed human red blood cells. This new method, which enables sarin's hydrolysis products to be detected in BIMP-exposed erythrocytes, is a useful tool for studying sarin-poisoning victims. |
1-Nitropyrene (1-NP) has successfully been used as a marker for environmental monitoring of exposure to diesel exhaust. This study presents a sensitive and selective method for detection of Hb adducts after oral administration of a single dose 1-NP to rats, by measuring 1-aminopyrene (1-AP) after in vitro hydrolysis of the adducts. Released 1-AP was extracted with hexane and derivatized with heptafluorobutyric acid anhydride prior to GC-MS-MS analysis. Optimal conditions for the release of 1-AP were hydrolysis under nitrogen, in 1 M NaOH at 70 degrees C for 60 min. Analysis of a stock solution of Hb adducts of 1-NP utilizing these conditions showed to be reproducible over a period of several weeks with a coefficient of variance of 9.5%. The determination limit was 10-20 pg 1-AP per 70-90 mg globin. A study of the time course of Hb adduct formation showed a fast absorption and an early peak concentration of released 1-AP, approximately 39 pg 1-AP/mg globin at 3 h after exposure. After the maximum was reached, 1-AP concentrations decreased bi-phasically. Initially a fast decline was observed, followed by a slow decrease to 5.9+/-1.9 pg 1-AP/mg globin at 24 h after administration. |
The alkylchloroformate derivatisation and solid-phase microextraction of amphetamine and methamphetamine directly in urine samples prior to capillary gas chromatographic analysis is described. The alkylchloroformate reagent was added to the urine sample, which was adjusted to pH 10.8, and an internal standard was added. The resulting products were water-stable carbamates that were extracted without organic solvent. The polydimethylsiloxane coated fibre was inserted into the modified sample and agitated for 14 min. The fibre with the extracted derivatisation products was injected into the capillary gas chromatograph. The extracted carbamates were evaporated at 300 degrees C in the split-splitless injection port of the gas chromatograph, separated on a methylsilicone capillary column and detected by either a nitrogen-phosphorus detector or by mass spectrometry. The method was shown to be reproducible with a detection limit of 50 ng/ml of amphetamine and methamphetamine in urine. |
The potential of on-line combination of supported liquid membrane extraction and column liquid chromatography with a phenol oxidase-based biosensor as a selective detection unit has been investigated for the determination of phenols in human plasma. The phenols are selectively extracted into a porous PTFE (polytetraflouroethene) membrane impregnated with a water-immiscible organic solvent and further into an alkaline acceptor phase. Via an ion-exchange interface, the analytes are transferred to a reversed-phase column where they are separated and detected using the biosensor. No sample pretreatment before the extraction, except centrifugation, is made. Due to the high selectivity both in the extraction and in the detection steps and to the fact that the demands on the chromatographic separation are low, a quick separation using an eluent with a low concentration of organic modifier can be made, without affecting the biosensor response. Detection limits below the 50 microg/l level in blood plasma were obtained for the three model compounds, phenol, p-cresol and 4-chlorophenol. |
A reliable and sensitive method for the determination of triazolam in human muscle using gas chromatography-mass spectrometry (GC-MS) is described. The drug was extracted from decomposed human muscle using three-step liquid-liquid extraction and HPLC which was performed isocratically on a conventional ODS column with a mobile phase of 0.01 M phosphate buffer (pH 6.5)-acetonitrile (7:3). Estazolam was used as an internal standard. GC-MS analysis was performed on a DB-5 capillary column. Excellent linearity was obtained over the concentration range 1-200 ng/g. The lower limit of detection was approximately 0.5 ng/g. Forensic application of the present method was also described. |
A sequential achiral-chiral HPLC method has been developed for the stereospecific analysis of the two major urinary metabolites of ibuprofen, namely hydroxyibuprofen and carboxyibuprofen. Achiral analysis was carried out using a Partisil column (250x4.6 mm, 5 microm) and a mobile phase of hexane:ethanol (98.2:1.8, v/v) containing trifluoroacetic acid (TFA; 0.05%, v/v) at a flow-rate of 2.0 ml/min. The HPLC eluate containing the two metabolites was separately collected, evaporated under nitrogen and the residue dissolved in the mobile phase used for chiral chromatography. Chiral-phase analysis was carried out using a Chiralpak AD CSP (250x4.6 mm, 10 microm) with a mobile phase of hexane:ethanol (92:8, v/v) containing TFA (0.05%, v/v) at a flow-rate of 1.0 ml/min. In both assays the analytes were quantified by ultraviolet detection at a wavelength of 220 nm. Modification of the mobile-phase composition allowed the resolution of all six analytes in a single chromatographic run but with an increase in run time and consequent band broadening. The analytical method described allows the direct quantitation of the stereoisomers of both metabolites of ibuprofen in urine following the administration of therapeutic doses of the racemic drug to man. |
Since pharmacokinetics may play a significant role in furosemide (FSM) developmental ototoxicity, we developed an assay for the extraction and quantification of FSM in tissue and fluid from neonatal and adult rats. Rats from post-natal day (PND) 10, 30 and 50, were given an intravenous dose of FSM (35 mg/kg). Blood and tissues were analyzed by HPLC. FSM in serum, perilymph and liver was elevated in PND ten rats as was the body burden of FSM. Renal concentrations were higher in older rats. Altered clearance of FSM in developing rats may result in higher concentrations in the cochlea and ototoxicity. |
Enantiomers of warfarin and 7-hydroxywarfarin in human plasma and urine, respectively, were determined by high-performance liquid chromatography using a cellulose-derivative column with UV or fluorescent detection, and their absolute configuration was determined simultaneously by a circular dichroism spectropolarimeter connected in series. Enantiomers of warfarin and its major metabolites [i.e., (R)-6-hydroxywarfarin, (S)-7-hydroxywarfarin and (RS)-warfarin alcohol] were well resolved. The method was precise and sensitive: within- and between-day coefficients of variation were <9.6% for warfarin enantiomers in plasma and <7.1% for 7-hydroxywarfarin enantiomers in urine, respectively, and the lower detection limits were 20 ng/ml for (R)-warfarin, 40 ng/ml for (S)-warfarin, 2.5 ng/ml for (R)-7-hydroxywarfarin and 4.5 ng/ml for (S)-7-hydroxywarfarin in 0.5 ml of both plasma and urine. The ultrafiltration technique was used for determining unbound concentrations of warfarin enantiomers in plasma using [14C]warfarin enantiomers resolved by the present HPLC system. Clinical applicability of the method was evaluated by determining unbound concentrations of warfarin enantiomers in five consecutive plasma samples obtained from a patient exhibiting an unstable anticoagulant response to warfarin (4 mg/day, p.o.). Results indicated that the present method would be useful in clarifying factors responsible for a large intra- and inter-patient variability in warfarin effects with regard to unbound plasma enantiomer pharmacokinetics. |
A simple, reliable high-performance liquid chromatographic (HPLC) method has been developed and validated for the determination of noscapine in human plasma. Noscapine and the internal standard, papaverine were quantitatively extracted from plasma onto disposable extraction columns by means of an automated off-line solid-phase extraction system and were separated onto a reversed-phase column. The method was found to be precise and accurate within the range 7.2-270 ng/ml. No endogenous compounds interfered with the assay. |
The development of the ASTED (automated sequential trace enrichment of dialysates) system to prepare plasma samples prior to high-performance liquid chromatography (HPLC) of sildenafil and its demethylated metabolite (UK-103,320) is described. Investigations to elucidate potential pitfalls of the ASTED on-line sample preparation system prior to separation of the analytes by HPLC are presented. The procedure is shown to be selective for sildenafil and UK-103,320, and linear over the range 1.00-250 ng/ml. The intra-batch imprecision (C.V.) of the method at plasma analyte concentrations of 1.00, 5.00, 50.0 and 200 ng/ml was 11.2, 3.10, 1.50, and 1.30%, respectively, and the corresponding inter-batch imprecision was estimated to be 13.5, 7.09, 3.69, and 5.43%. At these plasma analyte concentrations the overall inaccuracy (% bias) of the procedure ranged from 3.6 to 8.4%. The method showed similar assay performance for the estimation of the metabolite, UK-103,320. The application of the assay to a pharmacokinetic investigation during a clinical study is presented. |
A new ion-pair HPLC method coupled with evaporative light-scattering detection (ELSD) for the simultaneous determination of clodronate and its partial esters has been developed. The simultaneous chromatographic separation was achieved on a reversed-phase C8 column with a gradient system and butylamine as an ion-pair reagent. This method provides good enough reproducibility and sensitivity for in vitro determinations of clodronate and its ester derivatives. The method is applied for hydrolysis studies of clodronate monoesters which have been described as possible prodrugs of clodronate. |
Iofratol is currently under evaluation as a potential X-ray contrast medium for angiography and myelography. An HPLC method for assaying iofratol in rat and human plasma and urine samples is described. The analysis is based on the reversed-phase chromatographic separation of iofratol and the internal standard (iopamidol) from the endogenous components of biological fluids, and detection by UV absorption at 242 nm. The selectivity of the method was satisfactory. The mean absolute recovery was greater than 90%. The precision and accuracy of the analytical methods were in the range 0.8-7.4 and -7.8 to +9.7%, respectively. The detection limits in plasma (0.1 ml) and urine (0.5 ml) were 0.1 and 0.4 microg (iofratol)/ml, respectively. The analyte was stable in the different biological matrices when stored at room temperature (20 degrees C) for at least 1 day, 4 degrees C for 1 month and -20 degrees C for 1 year. |
3,4-Dihydroxybenzylamine (DHBA) is commonly used as the internal standard in HPLC catecholamine assays. Sheep are frequently used in studies of cardiovascular physiology and in such studies measurement of catecholamines is important. The recovery of DHBA from sheep plasma is, however variable and poor. Therefore, we have developed a reliable and sensitive HPLC-ED method with alumina extraction for measurement of catecholamines in sheep plasma using deoxyepinephrine (epinine) as the internal standard. Separation was performed on a muBondapak C18 column (300x3.9 mm, 10 microm) with a mobile phase containing 2% acetonitrile and 98% buffer (0.05% sodium acetate-0.02% EDTA-0.013% sodium heptanesulfonate), pH 3.25. The extraction of epinine from water, human plasma, dog plasma and sheep plasma did not differ (p>0.05), but extraction of DHBA from sheep plasma was significantly impaired (p<0.0001). The R2 of regression curves (n=5) of norepinephrine (NE) (25.02 pg/ml-1.00 ng/ml) and epinephrine (E) (25.82 pg/ml-1.03 ng/ml), using epinine as internal standard were greater than 0.99. The intra- and inter-day coefficients of variation were 2.11-11.15 and 0.88-12.60% for NE and 1.12-10.91 and 2.88-12.60% for E, respectively. The detection limits for NE and E are 12 pg/ml. The technique described has the advantage that it allows the simultaneous determination of both endogenous and [3H]norepinephrine in sheep plasma using a sensitive and reproducible HPLC technique. |
A high-performance liquid chromatography method for the determination of thiamine diphosphate (vitamin B1) in erythrocytes is presented. The method is robust, accurate and reproducible and due to the use of acetylaneurine as an internal standard, offers advantages over previous methods. |
Smoking and other forms of nicotine consumption are among the most important risk factors for cardiovascular disease and cancer. Many of the cessation therapies require administration of nicotine. Accordingly, precision analysis for nicotine in plasma has become increasingly important. Several of the recently published methods require elaborate sample handling and/or processing. We report a simple, rapid and reliable gas chromatography method with a high sensitivity for determination of unchanged nicotine in plasma, which can be used in the processing and quantification of large series of nicotine samples, e.g., in clinical trials of nicotine-based smoking or tobacco cessation drug delivery systems. |
A high-performance liquid chromatographic assay for the oxidative metabolites of dihydrocodeine, nordihydrocodeine and dihydromorphine, formed in human liver microsomal incubations, is described. A simple solvent extraction followed by reversed-phase high-performance liquid chromatography with UV detection allows quantification of both metabolites in a single assay. Standard curve concentration ranges for dihydromorphine and nordihydrocodeine were 0.05-5 and 0.2-20 microM, respectively. Assay performance was assessed by intra- and inter-day accuracy and precision of quality control (QC) samples. The difference between the calculated and the actual concentration and the relative standard deviation were less than 15% at low QC concentrations and less than 10% at medium and high QC concentrations for both analytes. The method provides good precision, accuracy and sensitivity for use in kinetic studies of the oxidative metabolism of dihydrocodeine in human liver microsomes. |
A reversed-phase high-performance liquid chromatographic (HPLC) assay was developed to analyze capsaicin and zucapsaicin (civamide) in human serum at concentrations from 1 to 100 ng/ml. Human serum specimens were extracted twice with hexane-methyl tert.-butyl ether (1:1). The chromatographic separation was carried out on a C18 column at 40 degrees C using a mobile phase consisting of 40% acetonitrile in water with 5% tetrahydrofuran and 1% acetic acid. The concentration of the eluting compounds was monitored by a fluorescence detector with excitation at 270 nm and an emission cutoff of 300 nm. No interferences were observed from the extract of blank serum. The standard curves were linear in the detection range. The relative standard deviation of the assay was better than 8.4%. The limit of detection was 0.5 ng/ml. |
A simple liquid chromatographic method using amperometric detection was developed for the determination of naltrexone in human plasma. Prior to analysis, naltrexone and the internal standard (naloxone) were extracted from plasma samples using a 9:1 mixture of chloroform and isopropyl alcohol. The mobile phase comprised 0.1 M disodium hydrogen orthophosphate (pH 3.5) and acetonitrile (85.5:14.5, v/v). Analysis was run at a flow-rate of 0.8 ml/min with the detector operating under oxidative mode at an applied potential of +0.95 V. The method is specific and sensitive with a detection limit of approximately 1 ng/ml at a signal-to-noise ratio of 3:1. Mean recovery value of the extraction procedure was about 93%, while the within day and between day coefficient of variation and percent error values of the assay method were all less than 10%. The calibration curve was linear over a concentration range of 1.5-100 ng/ml. |
The expression of interleukin-1 alpha (IL-1 alpha) appears to be tightly regulated, as the levels of constitutive expression in normal cells is extremely low. In contrast to normal hematopoietic cells, human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines constitutively produce high levels of IL-1 alpha mRNA and secret this cytokine into the culture medium. IL-1-alpha mRNA is also expressed in fresh leukemic cells of adult T-cell leukemia/lymphoma (ATLL) patients. HTLV-I-induced IL-1 alpha might explain some symptoms observed in ATLL. In this regard, molecular dissection of the IL-1 alpha gene transcriptional regulation is of primary importance. In this review, the transcriptional regulation of IL-1 alpha gene expression and the possible role of the NF-kappaB pathway are discussed in the light of our current understanding of IL-1 alpha gene regulation by HTLV-I and HTLV-II Tax proteins, which are viral transcriptional transactivators. |
The transplantation of allogeneic peripheral blood progenitor cells (PBPC) provides complete and sustained hematopoietic and lymphopoietic engraftment. In healthy donors, large amounts of PBPC can be mobilized with hematopoietic growth factors. However, the high content of immunocompetent T-cells in apheresis products may expose recipients of allogeneic PBPC to an elevated risk of acute and chronic graft-versus-host disease. Thus, the use of appropriate T-cell reduction, but not depletion might reduce this risk. The hazards of graft rejection and a higher relapse rate can be avoided by maintaining a portion of the T-cells in the graft. The positive selection of CD34+ cells from peripheral blood preparations simultaneously provides an approximately 1000-fold reduction of T-cells. These purified CD34+ cells containing committed and pluripotent stem cells are suitable for allogeneic transplantation and can be used in the following instances: 1. As hematopoietic stem and progenitor cell transplantation instead of bone marrow cells, from HLA-identical family donors; 2. for increasing the stem cell numbers from HLA-mismatched or three HLA-loci different family donors in order to reduce the incidence of rejection but without increasing the T-cell number; 3. boosting of poor marrow graft function with stem cells from the same family donors; 4. transplantation from volunteer matched unrelated donors; 5. split transplantation of CD34+ and T-cells; 6. addition of ex vivo expanded CD34+ cells to blood cell or bone marrow transplantation; 7. generation of antigen specific immune effector cells and antigen presenting cells for cell therapy. |
The marginal zone of the B follicle represents a well-defined compartment of the B area. Its cellular composition is distinct from that of the follicle centre, from which it also differs in its functional role in the immune response. Several newly identified lymphoma entities, e.g. extranodal MALT type lymphoma, nodal monocytoid B-cell lymphoma and splenic marginal zone B-cell lymphoma, display in common a very peculiar organoid growth pattern reminiscent of the marginal zone. Moreover, their neoplastic components share morphologic and phenotypic similarities to the cellular components of the marginal zone. The clinical characteristics of these various marginal zone cell lymphomas may differ depending of the organ which is involved. Nevertheless, they all share common cytogenetic abnormalities suggesting a common pathogenesis. |
Since the initial report of adult T-cell leukemia (ATL) in 1976, a number of investigators have described the basic biologic aspects of this disease. However, the precise mechanism of leukemogenesis remains unclear. Primary ATL cells demonstrate autonomous and IL-2 responsive growth in vitro. The autonomous growth of the cells is thought to be mediated by IL-2 in an autocrine manner, at least in part. These growth activities are related inversely to survival, and may be useful prognostic determinants. The viral Tax protein stimulates IL-2 and IL-2 receptor alpha expression via nuclear transfer factor NF-kappaB induction. We showed that marked activation of the Tax-NF-kappaB pathway is seen only in acute-type ATL patients. Recent studies show that mutations of p16 and p53 are also found in acute and lymphoma-type ATL. These appear to be late events in ATL leukemogenesis. The relationship between activation of Tax-NF-kappaB pathway and mutations of p53 and p16 genes is unknown. A few other genetic events may be involved in earlier stages of the entire process of ATL leukemogenesis, leading to smoldering and chronic-type ATL. These gene mutations may be accumulated by Tax protein during the long process from the time of HTLV-I infection to the onset of ATL. |
The understanding of the biology of multiple myeloma has advanced significantly in the past few years. The identification of the pivotal role of Interleukin-6 (IL-6), the soluble IL-6 receptor (sIL-6R), and how the ligand receptor complex interacts with the signal transducer gp130 has provided new biological insights into plasma cell disorders. Some studies have suggested that sIL-6R levels may have prognostic significance in MM, however this is not a consistent finding. Here the biology and function of IL-6 and sIL-6R are reviewed and the clinical significance of sIL-6R discussed. |
Despite lack of cross-resistance with vincristine and a somewhat different toxicity spectrum, the semi-synthetic vinca alkaloid, vindesine, has not yet achieved its expected potential in the treatment of acute leukaemias. The ability of vindesine to induce remissions in vincristine-resistant and relapsed ALL is of particular interest for the development of potentially curative second-line regimens. Vindesine may also have a role in consolidation strategies for de novo ALL, although it will be difficult to demonstrate specific advantages for this agent as part of a multidrug treatment approach. In myeloid leukaemias, while vindesine appears to have a limited role in ANLL, it may be useful for the palliative treatment of CML blast crisis. In the future, new synergistic combinations, incorporating vindesine with for example, methotrexate or edatrexate, may be developed. |
The use of CSCT to judge suitability for DIT and AHSCT in patients with aggressive-histology lymphoma who recur after primary chemotherapy is a widespread practice that excludes many NHL patients from this potentially curative therapy. Surprisingly, little direct evidence exists to suggest that CSCT used in this way is a useful strategy. On the other hand, it is clear that many of these patients undergoing DIT and AHSCT will not be cured using any currently available strategy or technique, and a method to identify such patients would be most helpful. CSCT may or may not be the best way to do so. This is an important question, but currently there are insufficient data to give us a definitive answer. Clinical trials are needed to resolve the issue. If the utility of CSCT is not validated, it should be abandoned. If it is validated, however, we may begin to address ways in which CSCT may be given more effectively. |
We report a series of 37 cases of lymphoproliferative disorders with 3q27 structural chromosomal abnormalities. Breakpoints at 3q27, the site of the bcl-6 gene, appear in a broad range of B cell lymphoma histologies but are most frequently detected in follicular lymphomas lacking a t(14;18) and diffuse large cell lymphomas. The majority of 3q27 rearrangements result from translocations involving the immunoglobulin heavy or light chain genes, however, involvement of other partner chromosomes is also observed. Molecular rearrangement of bcl-6 is demonstrable in a subset of cases. Bcl-6 is a recently identified gene encoding a zinc-finger protein. It is normally expressed in germinal center B cells where it is believed to have a developmental or differentiation function. Transcriptional deregulation of bcl-6 through translocations, submicroscopic molecular rearrangements or point mutations may be responsible for this gene's putative lymphomagenic potential. |
The purpose of this paper is to report the clinical characteristics and treatment outcome following different therapeutic approaches in a large series of patients with primary low-grade MALT lymphoma of the stomach. A total of ninety-three patients (median age 63 years) were reviewed. The patients were treated by different modalities (local treatment alone, combined treatment, chemotherapy, antibiotics alone); seven patients refused any treatment. The antibiotic-treated group of patients was prospectively followed with regular endoscopic biopsies, and their responses were histologically evaluated. The 5-years projected overall survival is 82% (95% C.I.; 67%-91%) in the series as a whole. Second tumors were observed in 21.5% of the patients in this series (95% CI 14%v to 31%). There was no apparent difference in overall survival and event-free survival between patients who received different treatments. In the antibiotic-treated group histologic regression of MALT lymphoma was documented in 67% of patients (95% CI 51% to 80%). In conclusion the indolent nature of the disease justifies a conservative approach. The use of antibiotics as first-line therapy may avert or at least postpone the indication for surgical resection in the majority of patients. |
We reviewed 77 cases considered as lymphocytic lymphomas of intermediate differentiation or diffuse centrocytic lymphomas. Forty-five cases were diagnosed as mantle cell lymphoma (MCL). The architectural pattern was diffuse in 95%, 8 cases presented large blastoid cells and CD5 positivity was observed in 28/34 cases. Of 20 cases studied, 8 presented a t(11;14)(q13;q32). Patient characteristics were: median age 59 years, B symptoms in 38%, 87% stages III-IV, bone marrow involvement in 67% with peripheral leukemic cells in 24%. Forty-four patients were treated with chemotherapy and 7 received radiotherapy. The complete response (CR) rate was 58%. Of the 26 CR, 19 relapsed at a median of 15 months. Disease-free survival was 42% and overall survival was 73% at 3 years. In a univariate analysis, overall survival was related to liver and bone marrow involvement, the presence of peripheral lymphomatous cells and achieving a complete response. |
The protooncogene p56lck is considered to participate in malignant transformation of lymphoid cells. In order to evaluate the role of this tyrosine kinase in B cell neoplasias, we investigated the expression of p56lck by Western blot analysis. In 12/16 Burkitt's lymphoma derived cell lines, 3/3 lymphoblastoid cell lines, 1/6 Hodgkin's disease derived cell lines, and 10/10 freshly isolated chronic lymphocytic leukemia cells constitutive expression of the protein was detected. Protein tyrosine kinase assays detected a catalytic active form of p56lck in all p56lck expressing samples. Stimulation experiments of the different cell lines and primary tumour cells by the phorbol ester TPA and the B-cell specific stimulation with SAC/anti-IgM respectively indicated a change of the expression level in comparison with the unstimulated cells and, a higher molecular weight species of the protein tyrosine kinase p56lck was observed. This was probably due to hyperphosphorylation of p56lck. No correlation between an infection with the Epstein-Barr virus and the expression of p56lck was found in the cell lines used and in primary tumour cells. Inhibition of p56lck activity by the specific inhibitor 4-amino-6-hydroxyflavone revealed a decrease of proliferation of the T-cell line Jurkat, but not of the Burkitt's lymphoma cell lines. In the analysed cell lines we found a reduction of the kinase activity of p56lck of approximately 70%. These results suggest that lck may contribute to the maintenance of the transformation of the analysed B cell neoplasias but that lck does not support a model for an initial event in B cell transformation. |
Tumor cells, and particularly leukemic cells, can be considered as maturation-arrested cells which have escaped some normal control and continue to proliferate. This maturation arrest can be reversed by differentiation agents such as antitumor drugs currently used in conventional cytotoxic chemotherapy. In this respect, anthracyclines have been shown to trigger the differentiation of leukemic and solid tumor cells, but the molecular mechanisms by which such drugs lead to the differentiating phenotype are still poorly understood. Using human leukemic multipotent K562 cells, we have demonstrated that subtoxic concentrations of aclacinomycin (ACLA) and doxorubicin (DOX) preferentially stimulate the hemoglobinic pathway (globins and heme synthesis) and the expression of mRNAs of globins and of porphobilinogen deaminase (PBGD). However, our results indicate that both drugs exert this differentiating effect along distinct regulatory pathways. Indeed, only ACLA and not DOX induces the expression of erythropoietin receptor (EpoR) mRNAs and of membrane EpoR, as well as an overexpression of the erythroid transcription factors GATA-1 and NF-E2 known to play a central role in erythroid gene regulation. Similarly, using transfection assays, ACLA but not DOX activates the regulatory regions (promoters and enhancers) of GATA-1, EpoR, PBGD, epsilon- and gamma-globin genes. Finally, results of run-on assays indicate that ACLA induces an enhancement of the transcription rate of these erythroid genes whereas DOX preferentially increases stability of GATA-1, NF-E2 and PBGD mRNAs. In conclusion, ACLA mainly acts at the transcriptional level via specific activation of erythroid regulatory regions whereas DOX rather acts at the posttranscriptional level by increasing the half-lives of erythroid mRNAs. |
In this study, 54 patients with relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated in a phase II, multicentric trial with ifosfamide-mesna 1500 mg/m2 IV days 1-3, idarubicin 12 mg/m2 IV day 1 and etoposide 100 mg/m2 IV day 1-3 (MIZE). Overall response was 72%; complete response (CR) and partial response (PR) were 46% and 26% respectively. In Stage I-II pts CR was 59% and in Stage III-IV pts CR was 40.5%. Patients who relapsed from an initial CR had a 64% CR rate when treated with MIZE, in contrast to refractory disease's patients who only had 19% CR (p = 0.004). The group of pts that had an objective response (CR + PR) to front line therapy had a 2 year survival rate of 55% compared with none for refractory disease (p = 0.029) after salvage therapy. Median survival for the entire group was 17.5 months. Better survival was seen in pts who were asymptomatic with low levels of LDH, previous CR, non high-grade histology, and limited disease stage at relapse. Toxicity was mainly hematologic: 91.5% had neutropenia, (56.5% grade III-IV), and 9.5% died from infectious complications. Other clinical toxicities including cardiac toxicity were negligible. MIZE chemotherapy was effective in patients with relapsed and refractory lymphoma and showed limited clinical and cardiac toxicity. Myelosupression was the most frequent single toxicity. |
The human HMGI-C gene encoding a member of the high mobility group protein family normally is expressed only during embryonic/fetal development but in none of the adult tissues tested so far. Recently, the HMGI-C gene has attracted a lot of interest since its rearrangements seem to underlie the development of frequent benign mesenchymal tumors. We have therefore checked CD34 positive hematopoietic stem cells and their normal and malignant descendants for HMGI-C expression. CD34 positive stem cells from healthy donors and the leukemia samples tested were positive while all peripheral blood samples from healthy volunteers were negative. We have concluded that the expression of the HMGI-C gene in leukemia seems to be a secondary effect due to abnormal stem cell proliferation and might be a sensitive tumor marker for particular types of leukemia. |
Primary lymphomas arising in the adrenal gland are extremely rare. The presenting symptoms are nonspecific and may be related to lymphoma or to associated adrenal insufficiency. In this report we describe the case of a 61 year old woman with idiopathic thrombocytopenic purpura and primary bilateral non Hodgkin's lymphoma of the adrenals. |
We present the case of a two-year-old child with an atypical presentation of chronic myeloid leukemia. At diagnosis, he showed clinical and biological features of juvenile chronic myeloid leukemia (CML). However, eosinophilia was observed in blood and bone marrow. The bone marrow karyotype did not demonstrate the Philadelphia chromosome but BCR-ABL rearrangement was shown to be present by reverse transcriptase polymerase chain reaction (RT-PCR) analysis and confirmed by fluorescent in situ hybridization (FISH) analysis. Discussion centres on the differentiation between juvenile CML and childhood chronic myelogenous Leukemia and the importance of carrying out RT PCR for all juvenile CML cases. |
Acute myeloid leukemia (AML) is infrequent in patients with human immunodeficiency virus (HIV) infection. Among AML, acute promyelocytic leukemia (APL) has been rarely described in such patients, with only one case being published. We report a 30 years-old intravenous drug abuser HIV-infected male with APL who attained complete clinical, morphological, and molecular remission after differentiation therapy with all-trans-retinoic acid (ATRA) followed by intensive chemotherapy. The results of treatment in this patient and in other AML published cases suggest that therapy for AML should not be modified because of HIV infection if patients have an adequate performance status. |
A woman with Philadelphia chromosome-positive c-ALL with +8 and i17q in addition underwent an unpurged blood stem cell autograft after 200mg/m2 melphalan in first relapse. Maintenance therapy with 6-mercatopurine was started following the autograft. Moderate pancytopenia developed after 4 months, and myelodysplasia (refractory anemia) was diagnosed which rapidly evolved into AML. The cytogenetic findings remained unchanged. She also developed CNS disease, but the blasts in the cerebrospinal fluid were lymphoid in character on immunophenotyping. She then received palliative treatment until death. The remarkable features here are the evolution into myelodysplasia and AML with retention of the original complex karyotype, and subsequent coexistence of lymphoid disease in the CNS and myeloid disease systemically. It is possible that the lineage switch and development of myelodysplasia in this case may have been secondary to treatment, but persistence of the original cytogenetic clone makes this unlikely. This may have been the result of some unusual effect of the treatment on the original clone, or expansion of a small unidentified myeloid clone present originally which gained a proliferative advantage due to the ALL-type treatment. This case confirms the aggressive and polymorphic nature of Ph+ ALL which may be the result of origin from an early progenitor cell (stem cell disease). |
An unusual case of bullous pyoderma gangrenosum in a patient with myelodysplastic syndrome during treatment with granulocyte colony-stimulating factor (G-CSF) is reported. The possible relationship between G-CSF therapy and pyoderma gangrenosum, as well as the beneficial effect of cyclosporin A therapy, is discussed. |
The current public debate on nicotine concentrates on the abuse potential of nicotine per se. However, little is known about the interaction of nicotine with other drugs of well-established abuse liability such as cocaine. Indeed, cigarette smoking increases the intake of cocaine and other drugs of abuse. In order to test if these epidemiological data are reflected in a neurochemical correlate of the reinforcing effects of drugs of abuse, i.e., dopamine overflow in the nucleus accumbens, in vivo brain microdialysis was used to examine the effects of nicotine and cocaine either alone or in combination in freely moving rats. Furthermore, the effects of the nicotine + cocaine combination were compared to another drug combination of high abuse potential, i.e., heroin + cocaine ('speedball'). Both nicotine + cocaine as well as heroin + cocaine stimulated nucleus accumbens dopamine overflow in an additive manner. Repeated intermittent administration of nicotine did not significantly alter the effects of a subsequent challenge with the nicotine + cocaine combination. These data suggest that the clinical-epidemiological findings on either drug combination are reflected in a stimulatory interaction on nucleus accumbens dopamine overflow that is additive. No significant tolerance seems to develop to this effect of nicotine. These neurochemical findings support behavioral data suggesting that the reinforcing effects of cocaine and heroin are additive and predict that nicotine will enhance the reinforcing effects of cocaine. |
The formalin test, an experimental model of injury-induced central sensitisation, was used. The antinociceptive interaction between intrathecal morphine and clonidine was evaluated based on the inhibition of the phase 1 and 2 of the formalin response, induced by both drugs, given alone or in combinations with fixed dose ratios. Morphine and clonidine, at doses not affecting motor performance, produced dose-dependent inhibition in the formalin test, with similar ID50 values in phase 1 and 2; 0.66 and 0.45 nmol and 4.1 and 3.5 nmol, respectively. Isobolographic analysis revealed a significant synergy. The combination ID50 was found to be significantly lower than the respective theoretical additive ID50 for both fixed dose ratios (1:3 and 1:10) in both phases of the formalin test. The similar total dose fraction of the additive ID50 in phase 1 and 2 indicates the same magnitude of synergy and may suggest that the mechanisms of the spinal clonidine-morphine synergy do not differ significantly between both phases of the formalin test. |
The effect of neurosteroids on the development of morphine tolerance and dependence was examined in mice. Development of tolerance to the antinociceptive effect of morphine sulfate (10 mg/kg, twice daily for 9 days) was measured in the tail-flick test and dependence was assessed from naloxone (2 mg/kg)-precipitated withdrawal jumps on day 10 of testing. Concomitant chronic administration of neurosteroids, allopregnanolone (0.5 mg/kg), pregnenolone sulfate (2 and 5 mg/kg) or dehydroepiandrosterone sulfate (2 and 5 mg/kg), followed by morphine (10 mg/kg) prevented the development of tolerance to the antinociceptive effect of morphine and suppressed the naloxone-precipitated withdrawal jumps. In contrast, dehydroepiandrosterone acetate (5 mg/kg) failed to modulate the morphine tolerance and dependence. The inhibitory effect was also seen upon concomitant administration of a neurosteroid precursor, progesterone (1-10 mg/kg), and a mitochondrial diazepam binding inhibitor receptor agonist, 4'-chlordiazepam (0.25-1 mg/kg), while an adrenocorticosteroid, hydrocortisone (1 and 10 mg/kg), failed to do so. However, acute treatment with these neurosteroids was not associated with any decrease in withdrawal jumping behavior in morphine-dependent mice. Neurosteroids themselves, at doses employed in the study, did not exert any effects on antinociception. These results support a role for neurosteroids in the development of tolerance to and dependence on morphine and suggest the potential utility of specific neuroactive steroids in its treatment. |
Clocinnamox is a long-lasting, nonequilibrium, mu-opioid receptor antagonist in mice and monkeys. The present studies examined the in vivo and ex vivo effects of clocinnamox in rats. Under control conditions, morphine dose-dependently increased tail-withdrawal latencies from 50 degrees C water, with a mean ED50 of 7.3 +/- 1.1 mg/kg. Clocinnamox antagonized the antinociceptive effects of morphine. 1.0 mg/kg clocinnamox displaced the morphine dose-response curve 4-fold to the right of the control curve and 10 mg/kg clocinnamox eliminated morphine's antinociceptive effects at doses up to 1000 mg/kg for at least seven days. There was a gradual recovery of the antinociceptive response to morphine; however, the morphine dose-response curve did not return to its original position by five weeks after 10 mg/kg clocinnamox. Whole brain membranes were prepared from separate groups of rats for determination of binding parameters of [3H][D-Ala2, N-Me-Phe4,Gly5-ol]-enkephalin (DAMGO). Clocinnamox dose-dependently decreased [3H]DAMGO binding ex vivo and the decreased binding was a result of changes in Bmax. The control Bmax for [3H]DAMGO was 234 +/- 8 fmol/mg protein; in membranes prepared from rats pretreated with 10 mg/kg clocinnamox, the Bmax value for [3H]DAMGO was 54 +/- 2 fmol/mg protein. The Bmax values for [3H]DAMGO binding after an injection of 10 mg/kg clocinnamox returned towards control values gradually, four weeks after clocinnamox the Bmax was 178 +/- 10 fmol/mg protein. These results suggest that clocinnamox is a long-lasting, nonequilibrium mu-opioid receptor antagonist in rats. |
Since the cardiovascular effects of cholecystokinin (CCK) seem to particularly involve the A ('peripheral') subtype of CCK (CCK[A]) receptor, we examined the actions of two novel, highly selective CCK(A) receptor antagonists, PD140548 (N-alpha-methyl-N[(tricyclo[3.3.1.1(3,7)]dec-2-yloxy)carbony l]-L-tryptophyl]-D-3-(phenylmethyl)-beta-alanine) and SR 27897B (1-[[2-(4-(2-chlorophenyl)thiazol-2-yl)aminocarbonyl]acetic acid) on CCK-induced alterations in blood pressure and heart rate, and on the baroreceptor reflex in the conscious, instrumented rat. CCK (2 microg, i.v.) produced a pressor response and biphasic effects on heart rate involving an initial bradycardia followed by a pronounced tachycardia. Administration of PD140548 (10 mg/kg, i.v.) and SR 27897B (0.6 mg/kg, i.v.) significantly inhibited the pressor effects of CCK (35 and 47%, respectively), whilst reversing the bradycardic responses to a tachycardia. The CCK(A) receptor antagonists had different effects on the baroreceptor heart rate reflex since only PD140548 caused a significant increase in the gain or sensitivity of the reflex. This effect of PD140548 on gain is likely to occur via a central mechanism and may reflect the increased lipophilicity of PD140548 relative to SR 27897B. Overall, these investigations provide new evidence for the involvement of the CCK(A) receptor in cardiovascular regulation. |
Acadesine, an adenosine regulating agent, attenuates the adverse effects of ischaemia on ventricular function in animals. This study examined its influence on pacing-induced ischaemia in 47 patients undergoing coronary angiography. After 15 min of recovery from control pacing, an infusion of acadesine (5, 10, 20, 50 mg/kg i.v.) was commenced and after a further 15 min the protocol was repeated with the infusion continued. At higher doses, minor beneficial effects on ejection fraction and myocardial lactate metabolism were observed. Haemodynamics were unaffected. Systemic lactate rose in relation to acadesine, up to 60% (P < 0.001 versus placebo). The data may indicate that acadesine stimulates anaerobic glycolysis in man. |
Avid Na+ retention is a hallmark of liver cirrhosis. The aim of this study was to investigate whether and how bradykinin is involved in Na+ retention in rats with CCl4-induced liver cirrhosis. To this end the bradykinin B2 receptor antagonist Icatibant (HOE 140) was used. On one hand, bradykinin has a renal natriuretic action. On the other hand, bradykinin is a potent mediator of both vasodilation and microvascular leakage. Both vascular mechanisms, which are reported for cirrhosis, could cause vascular underfilling and Na+ retention by activating the renin-angiotensin-aldosterone system. Icatibant normalised Na+ retention and reduced the hyperactivity of the renin-angiotensin-aldosterone system, suggesting a bradykinin-induced vascular disturbance. Icatibant had no significant effect on the mild hypotension which developed with CCl4 treatment. However, there was indirect evidence for enhanced microvascular leakage that was strongly inhibited by Icatibant. Our experimental results demonstrate that bradykinin is a key mediator of Na+ retention in liver cirrhosis and suggest that a bradykinin-induced increase in microvascular leakage is mainly responsible. |
The effects of novel nitric oxide (NO)-releasing oxatriazole derivatives GEA 3162 and GEA 3175 were studied on cell proliferation and cGMP synthesis in human peripheral blood mononuclear cells stimulated with a lectin mitogen concanavalin A. GEA 3162 (1-30 microM) and GEA 3175 (3-30 microM) inhibited mononuclear cell proliferation in a dose-dependent manner being more potent than the earlier known NO-donor S-nitroso-N-acetylpenicillamine. The inhibitory action was more pronounced when submaximally stimulating concentrations of concanavalin A (0.1 and 1 microg/ml) were used and no inhibition was seen when concanavalin A concentrations were increased up to 10 microg/ml. The antiproliferative concentrations of GEA 3162, GEA 3175 and S-nitroso-N-acetylpenicillamine induced a rapid and transient increase in cGMP production in mononuclear cells cultured in the presence of concanavalin A. Both the antiproliferative action and the increased cGMP production were attenuated when red blood cells were added into the cultures indicating that NO is responsible for both of these actions. An analogue of cGMP, 8-bromo-cGMP (0.1-3 mM) reduced concanavalin A-induced proliferation in a dose-dependent manner suggesting that cGMP may be involved in the antiproliferative action of NO-donors. NO-releasing compounds have immunosuppressive actions which offer therapeutic possibilities and should be kept in mind as potential adverse events when these compounds are used in other indications. |
Molecular modelling and site-directed mutagenesis were used to identify eleven amino acid residues which may be involved in antagonist binding of the human tachykinin NK1 receptor. Recombinant receptors were expressed in mammalian cells using the Semliki Forest virus system. Wild type and mutant receptors showed similar expression levels in BHK and CHO cells, verified by metabolic labelling. Binding affinities were determined for a variety of tachykinin NK1 receptor antagonists in SFV-infected CHO cells. The binding affinity for GR203040, CP 99,994 and CP 96,345 was significantly reduced by mutant Q165A. The mutant F268A significantly reduced the affinity for GR203040 and CP 99,994 and the mutant H197A had reduced affinity for CP 96,345. All antagonists seemed to bind in a similar region of the receptor, but do not all rely on the same binding site interactions. Functional coupling to G-proteins was assayed by intracellular Ca2+ release in SFV-infected CHO cells. The wild type receptor and all mutants except A162L and F268A responded to substance P stimulation. |