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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 721 records · Page 40Linked to original sources
PubMed1980

Simultaneous quantitation of chlormethiazole and two of its metabolites in blood and plasma by gas--liquid chromatography.

A simple and rapid gas chromatographic method for the quantitation of chlormethiazole and two of its pharmacologically active metabolites, 5-acetyl-4-methylthiazole and 5-(1-hydroxyethyl)-4-methylthiazole, in plasma and blood is described. The total analysis time is less than 20 min for a single sample. The method requires 50--500 microliter of plasma or 1 ml of blood. The compounds are detected with a nitrogen--phosphorus detector. An internal standard technique is used for the quantitation. Calibration data are linear over the range 32--2376 ng of chlormethiazole and a similar range of the metabolites in plasma. The method may be used for pharmacokinetic studies.

Adult↗
PubMed1980

Sorption of chlormethiazole by intravenous infusion giving sets.

The sorption of chlormethiazole by intravenous infusion giving sets was investigated. Average recoveries of chlormethiazole following 500 ml infusions were 78.5%, 82.2% and 71.2% for the IVAC Volume Infusion Set, Travenol Code AHC 2890 Blood Administration Set and the McGaw Metriset, respectively. The effluent concentration-time profile using set up procedures and infusion rates similar to those used clinically were followed. When compared to solutions flowing at an infusion rate of 75 and 150 ml/h, loss of chlormethiazole from solutions standing static in the infusion sets was higher while that of solutions flowing at a high rate of 999 ml/h was lower. The clinical and pharmacokinetic significance of these phenomena are discussed.

Adsorption↗
PubMed1980

Design of infusion regimens to achieve and maintain a predetermined plasma drug level range.

A method is proposed for the design of dosage regimens using two consecutive constant-rate intravenous infusions to rapidly achieve and maintain plasma drug levels within a predetermined range. By this method, the plasma level will rise to a predetermined maximum at the end of the loading infusion, decrease rapidly to a chosen fraction of the ultimate steady-state level, and then slowly rise to the steady-state level. The method may be particularly useful for drugs exhibiting extensive "multi-compartment" kinetics. Compared with other methods, this approach allows either or both a shorter loading infusion and a lower peak plasma level. Application of this method to clomethiazole therapy for the sedation of pregnant women at term is also discussed.

Anticonvulsants↗
PubMed1980

Expansion of services for medical students.

Increasing numbers of medical students and their rising expectations for services have often burdened the facilities of offices of student affairs. The successful utilization of professional counselors as well as personnel trained in financial aid and study skills counseling is discussed, as is a program which uses medical students as tutors and advisers of fellow students.

Counseling↗
PubMed1980

Acetylene reduction assay for nitrogenase activity: gas chromatographic determination of ethylene per sample in less than one minute.

Ammoniacal silver nitrate (10 mg/ml) was added to terminate acetylene reduction assays used to measure nitrogenase activity. Silver nitrate quantitatively precipitated acetylene as the carbide salt, but did not affect the ethylene formed. The vials containing ethylene can be analyzed gas chromatographically at the rate of about 13 samples in 10 min.

Journal Article↗
PubMed1980

The location of chronic gastric ulcer: a study of the relevance of ulcer size, age, sex, alcohol, analgesic intake and smoking.

Ulcer size, age, sex, alcohol and analgesic intake and cigarette consumption were studied in relation to the site of the ulcer in 215 patients with chronic gastric ulcer, of whom 96 were initial and 115 recurrent ulcers. Ulcer site was classified into upper (U), middle (M) and lower (L) thirds of the stomach, on X-ray films of air-contrast barium studies. The ulcers were situated in the upper third in 37 patients (17%), middle third in 90 patients (42%) and lower third in 88 patients (41%), i.e., significantly more in M and L compared to U (p less than 0.001). 135 ulcers were on the lesser curve (63%) with more in L and M compared to U (p less than 0.0005). Posterior wall ulcers accounted for 29.3%. Ulcers were smallest in L (mean 28.8 mm2) compared to those in M (mean 66.1 mm2) and U (mean 64.4 mm2) (p less than 0.001). Mean size overall was 49.0 mm. The mean age of the patients was 58.8 years with no significant differences in age between U, M and L (p greater than 0.9). The M/F ratio in the whole series was 0.6 which varied with ulcer site, being 0.3 in U (differing significantly from the whole series, p less than 0.05), 0.4 in M and 1.2 in L (significantly different from the whole series, p less than 0.01) and from U (p less than 0.01). Initial ulcers did not differ from recurrent ulcers except in women where initial ulcers were more common in M and L, whereas recurrent ulcers were more commin in U. The independent variables, namely, alcohol and analgesics (with the exception of smoking), were not determinants of ulcer site, size or position once the patients were segregated by sex. In men only, there were interactions between L and lesser curve site (p less than 0.004) and L and smoking (p less than 0.03).

Age Factors↗
PubMed1980

[Normal values of gastric acid secretion in Senegalese (author's transl)].

From a sample of 70 selected after gastric biopsies and who presented no gastroduodenal illness was proposed a table of reference of values of gastric acid secretion in Senegalese in their base state and after stimulation with a subcutaneous injection of 6 microgrammes per kilo of pentagastrine. The method of calculation is taken entirely from the one proposed by Bernier and colleagues (1973). The flow (or hourly volume) found in the sample are established in comparison with the thin mass and more precisely with the exchangeable potassium that was obtained in relation to the weight, age and sex. The comparison with European's secretion shows differences statistically significant for stimulated secretion. The hourly volume (average and standard deviation) are calculated for all subject in relation to the weight, age and sex.

Adolescent↗
PubMed1980

Chronic gastric ulcer and life events.

The purpose of this study was to define the frequency of stress preceding or during the course of chronic gastric ulcer (CGU). Stress was measured by the occurrence of 62 selected life events over 2 yr in two groups of CGU patients. One group (A) was studied for events during the 2 yr before their diagnosis (147 patients) and the second group (B) was studied for events occurring after diagnosis (73 patients). The ulcer groups were compared with community controls matched for age, sex, and social grade. Groups A and B did not differ in any significant way in their reported life events, indicating no temporal relationship between stressful life events and CGU. The combined ulcer groups, when compared with controls showed no differences in the number of events experienced or the associated scores for change and distress caused by the events. There was no difference in the order of the three most frequent events. Only the event "minor illness" was more frequent in controls on matched pairs analysis (P less than 0.05). The other 61 events showed no differences. When events were grouped into areas of activity, financial and legal events were reported by 38 patients and 23 controls (P less than 0.05). Significantly, few of these 38 patients were in the 60+ age range (P less than 0.02). Twenty-four patients reported no events, compared to 12 controls (P less than 0.05). Although there is no difference in the life events experienced by CGU patients and their controls, this assessment of stress has not taken account of the significance of the event as perceived by a particular individual, the ulcer patient perhaps reacting differently to stress and the ulcer being one result of this abnormal reaction. Consequently, the role of emotional stress remains open.

Adult↗
PubMed1980

Anterior dislocation of the hip and associated femoral-head fractures.

Fourteen of fifteen anterior dislocations of the hip, all fifteen being of the obturator variety, were treated initially by closed reduction. In thirteen of the patients fractures of the femoral head were noted, four being transchondral and nine of the indentation type. The fractures of the femoral head were definitely related to the outcome. Seven of the thirteen patients with fractures had fair or poor results, including all four with transchondral fractures and three of the six patients with indentation fractures that were more than four millimeters deep. Roentgenographic evidence of degenerative joint disease was present in ten of the thirteen patients with femoral-head fractures. The two patients without fracture had excellent results.

Adolescent↗
PubMed1980

[Should the pharmaceutical industry play an active part in pharmacosurveillance? (author's transl)].

The development of new drugs by pharmaceutical firms proceeds through different phases, i. e. pre-clinical studies and stage I, II and III clinical studies, which normally result in authorization to market. Once the drug is on the market, however, further research work is required to perfect its use and complete our knowledge of it. Stage IV clinical trials, which may be termed "pharmacosurveillance", fall as much as the previous ones within the responsibilities of the pharmaceutical industry, since reports on side-effects are collected and these may have practical applications. Thus, clinical research may be shifted towards possible new indications, or new pharmacological studies may be undertaken to elucidate the mechanism of some side-effects, develop them if they are beneficial, or find a way of preventing them if they are indesirable. With these considerations in mind, the authors have developed a protocol of pharmacosurveillance aimed at determining, through a preliminary in vitro study, the origin of some adverse reactions of anaesthetic drugs. Depending on the results of these studies, clinical applications are considered.

Anesthetics↗