Biomedical subjects
V Thomas
Publications and source records attributed to V Thomas.
Diagnostic and therapeutic procedures with haptens and glycoproteins (antigens and antibodies) coupled covalently by specific sites to insoluble supports.
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[Opinions and behavior of asthmatic patients towards treatment using aerosols].
An ever increasing number of drugs prescribed in the treatment of asthma are presented as aerosols, so that patients may be requested to inhale many puffs every day. In this study, the opinion of asthmatic patients was sought and their behaviour towards aerosols during attacks and in long-term treatment was recorded by means of a questionnaire. The answers confirmed that asthmatics liked aerosols and found them usually effective, but 60% of these patients exceeded the stated dose, and if the drug failed to bring the expected relief, 30% waited 24 hours before calling for a doctor. In long-term treatments, 80% of the patients studied said that 10 puffs a day were a nuisance, and 12% were switched to another treatment for that reason. These results are very important. Doctors should reinforce the patients' education and limit the number of daily puffs they prescribe to obtain better compliance of asthmatics with their treatment.
Cumulative dose-response curves for assessing combined effects of salbutamol and ipratropium bromide in chronic asthma.
We investigated whether salbutamol (S) and ipratropium bromide (IB) exerted a true additive bronchodilator effect in asthma. In fifteen selected chronic asthmatics, individual cumulative dose-response curves to S and IB were performed on two separate days (linear regression of bronchodilator response (delta FEV1) between 20 and 80% of maximal response, versus log dose), and the dose of S equipotent to the IB dose giving the maximal bronchodilator effect (IBopt) was calculated by interpolation of each S curve. On two other days, each patient received IBopt or the equipotent S dose followed by an additional 400 micrograms S. On day 1 or 2, FEV1 reached 220 +/- 410 ml and 2410 +/- 380 ml (p less than 0.05) after the maximal dose of IB and S respectively. On day 3 or 4 after pretreatment by IB or S an additional 400 micrograms S gave a further increase, which was similar in both series (315 and 320 ml, respectively). FEV1 after combination treatment reached 238 +/- 350 ml and was not significantly different from the maximal effect of S (2440 +/- 290 ml). We conclude that S and IB exert a true pharmacological additive effect, since the combination effect is as great as the maximal effect of the most potent drug (S) and greater than the maximal effect of IB, and that the same additional dose of S gives the same increase after equipotent doses of S and IB.
Outcome of neonatal hyperbilirubinemia managed with exchange transfusion.
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Protein-bound polyamines in the plasma of mice grafted with the Lewis lung carcinoma.
Protein-bound polyamines were isolated from the plasma of mice using antipolyamine antibodies covalently linked to magnetic latex spheres. Their subsequent separation by polyacrylamide gel electrophoresis (PAGE) showed that in plasma from normal mice, 3 proteins (27, 55 and 82 kDa) carrying polyamines could be visualized, whereas in mice bearing the Lewis lung carcinoma at least 8 other proteins of higher molecular mass (5 of 94, 110, 130, 145 and 160 kDa, and 3 of greater than 170 kDa) had bound polyamines. These protein-bound polyamines could be detected from the first week after tumour graft; they increased during the second and third week but decreased thereafter. These proteins were not bound by immunolatex spheres preincubated with spermine bound to a protein-carrier insulin. Moreover, the appearance of these protein-bound polyamines was not a consequence of the inflammatory process since in mice infected with heat-inactivated Brucella abortus, with the exception of a 65 kDa protein, polyamines were bound to the same proteins found in normal mice. In mice grafted with the Lewis lung carcinoma the concomitant decrease in transglutaminase-mediated polyamine (e.g. putrescine) binding capacity of plasma proteins provides additional evidence for the presence in vivo of polyamines already bound to plasma proteins.
[Demonstration of polyamines bound to plasma proteins during tumor growth].
Using antipolyamine antibodies covalently bound to magnetic latex spheres, we have been able to isolate from the plasma of mice bearing the Lewis lung carcinoma, 8 proteins with bound polyamines. These proteins are not found in the plasma of healthy mice or in those suffering with chronic inflammatory infection.
Mucosal abnormalities of the upper gastrointestinal tract in patients with portal hypertension: a reappraisal.
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The fromberg-Verma (FV) silicone lens--a series of 75 cases.
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Foreign body in the lung for 45 years without symptoms.
Patients with foreign bodies in the bronchopulmonary tree seldom remain asymptomatic for long (Abdul Majid et al. 1976). We report here a patient who aspirated a 22 carat gold safety-pin at 10 years of age and who continues to be free of respiratory symptoms 45 years later.
Does exercise alter anaerobic threshold in coronary artery disease during beta blockade?
The effect of propranolol on cardiac patients undergoing exercise training is reported to increase exercise tolerance and maximum oxygen uptake (VO2 max) but its effect on anaerobic threshold (AT) is unknown. It was the purpose of this study to determine the role of exercise training with propranolol on AT in patients with coronary artery disease (CAD). Eight men and one woman with significant (CAD) were selected for this study. Each patient completed a maximum treadmill stress test (MTST) following the Bruce protocol on propranolol 40-160 mg/day as a control study. Cardiorespiratory variables were measured at rest and at each stage of the treadmill test. These patients underwent an exercise training programme for 12-16 weeks on the same dose of propranolol. Training sessions were for a minimum of 30-40 minutes, 3 times a week, with training heart rate of 75%-85% of the pretraining peak heart rate. Training heart rate ranged from 98 to 128 beats/min. They were retested with a MTST after the training programme, on the same dose of propranolol. AT was calculated noninvasively by measuring respiratory variables every 30 seconds in relation to work increment. AT was identified by measuring the time course of VE, VCO2, VE/VO2, etc. in relation to incremental work. The mean values of VO2, O2P and % VO2 max at AT before and after training on propanolol were as follows: VO2 = 1.43 L/min +/- .25 and 1.86 L/min +/- .44, O2P = 14.35 +/- 2.40 and 18.73 +/- 4.00 ml/beat, % of VO2 max = 68.20 +/- 6.31 and 73.59 +/- 5.84. The mean changes of VO2 O2P, and % of VO2 max were + 0.43 L/min +/- 0.20 (P < .003), + 4.38 +/- 2.55 (P < .003) and +/- 5.07% +/- 4.84 (P < .001). After exercise training on propanolol, the mean peak exercise tolerance time and absolute VO2 max increased by 2.8 min (from 9.0 to 11.8 min) (P < .001) and 22.7% (P < .007), respectively. We conclude that the increase in anaerobic threshold in patients with coronary artery disease may be due to improvement in VO2 max, increased stroke volume, and peripheral O2 extraction.
Responses of cultured cardiac myocytes to lysosomotropic compounds and methylated amino acids.
Cardiac myocytes whose lysosomes had been pre-labelled with acridine orange were exposed to either L-amino acid methyl esters (L-leucine or methionine methyl ester) or to 'lysosomotropic' weak bases (chloroquine, methylamine, and NH4Cl) for 1 h. Both types of interventions dilated lysosomes equally and inhibited proteolysis to varying degrees. The weak bases produced no apparent alterations in the acridine orange staining, whereas the methylated amino acids induced a marked redistribution of the fluorescent dye from lysosomes into the myoplasm, suggesting that they may have provoked a change in lysosomal membrane permeability. A brief exposure to weak bases failed to enhance acid proteinase secretion into the culture medium but apparently inactivated cellular cathepsin B activity. In contrast, methylated amino acids induced no alterations in acid proteinase activity or the cellular distribution of the two proteolytic enzymes. Lastly, weak bases markedly elevated intralysosomal pH as measured with fluorescein dextran, while only modest rises were observed after amino acid methyl ester treatment. The present observations imply that amino acid methyl esters represent a new class of reagents with actions distinctly different from those of chloroquine and NH4Cl, and they may provide a unique and valuable means of studying secondary lysosomal function in cell culture.
Protein degradation and lysosomal proteinases in cultured fetal rabbit cardiac myocytes.
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A quantitative and qualitative study of the transglutaminase-mediated insertion of polyamines into plasma proteins from patients with bronchopulmonary cancer.
The transglutaminase-mediated incorporation of putrescine into proteins of plasma derived from 44 patients with histologically defined bronchopulmonary cancer was compared with that from an age-matched group of 18 patients hospitalized with non-malignant diseases. Two types of kinetic data were obtained over a range of putrescine concentrations 0.09 mM to 0.6 mM. Whereas the plasma from all the patients of the control group showed linear kinetics, that from only 24 patients of the cancer group showed linear kinetics. The remaining 20 showed kinetics typical of inhibition by excess substrate. PAGE analysis of [14C] putrescine-bound plasma proteins showed around 15 different bands. Among these putrescine-binding proteins, we identified, with the help of corresponding specific antisera, four protease inhibitors: alpha 2-macroglobulin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and antithrombin III.
The toxic effects of triorganotin(IV) compounds on the culicine mosquito, Aedes aegypti (L).
The structure-activity relationships of 25 triorganotin(IV) compounds were studied using the 4th instar A. aegypti larvae of the susceptible Liverpool Red-eye strain. The LC50 values of these compounds were compared with those of Malathion, DDT and Temephos. Maximal activities were obtained with tritolyltin chloride and its complexes with triphenyl-phosphine oxide and pyridine N-oxide, dimethyloctyltin- and diethyloctyltin acetates and tributyltin sucrose phthalate. A limited number of the triorganotin compounds was also tested with observed high activity against the 4th instar larvae of a local DDT-tolerant strain and against the 2nd instar larvae and adults of the susceptible strain. Delayed effect studies with both 2nd and 4th instar larvae showed high post-treatment mortality for the latter and, among the range of active compounds, the methyl- and aryltin compounds, in particular, were also found to exhibit high residual activities (100% kill) in laboratory tests conducted up to 10 weeks.
The esophageal obturator airway. A review.
The esophageal obturator airway (EOA) has been considered a beneficial ventilatory technique for use in cardiopulmonary resuscitation (CPR). At present, seven studies in the literature compare the EOA with other means of ventilation in humans; only one is an actual field study of its effectiveness. We reviewed the available literature dealing with the device to define clearly its role in the ventilatory treatment of patients who require CPR. There appears to be no current evidence of the EOA's effectiveness for ventilation in prehospital cardiac arrest, and fatal complications have been reported with its use. The use of the EOA to replace endotracheal intubation in airway management is not substantiated in the literature.
Duodenal ileus--report of five cases.
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