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Biomedical subjects

J Thornton

Publications and source records attributed to J Thornton.

At least 145 records · Page 8Linked to original sources
PubMed1981

The satiety effect of cholecystokinin: a progress report.

The satiety effect of cholecystokinin (CCK) that was first observed in rats has now been extended to chickens, rabbits, pigs, sheep, rhesus monkeys, lean mice, genetically obese mice and rats, neurologically obese rats, lean men and women, and obese men. The effect is specific and can be obtained in animals and humans without reports or signs of sickness. The mechanism of the effect is unknown, but the gastric vagal fibers are necessary for the effect. This has led to the hypothesis that the satiety effect is due to activation of vagal afferent fibers that inhibit the central control system of feeding by CCK acting directly on recently described vagal CCK receptors and/or indirectly through a gastric smooth muscle effect that vagal receptors are sensitive to.

Animals↗
PubMed1981

C-terminal octapeptide of cholecystokinin decreases food intake in man.

In comparison with a saline infusion, the infusion of the C-terminal octapeptide of cholecystokinin (4 ng/kg/min) decreased food intake by an average of 122 g in a group of 12 lean men without objective evidence of untoward side effects. Shapes of the cumulative intake curves under the two conditions were similar, but subjects ate less and stopped eating sooner when receiving octapeptide than when receiving saline. These results are consistent with the hypothesis that cholecystokinin is an endogenous signal for postprandial satiety. The results offer promise for the possible use of the octapeptide as an appetite suppressant.

Adult↗
PubMed1981

Quantitative studies of APUD cells in airways of rats. The effects of diethylnitrosamine and NO2.

A method of quantitating the airways amine precursor uptake decarboxylase (APUD) cells is proposed that relates these cells to total airway epithelial cells or airway length. In control rats, these values were 0.13 APUD cells/100 epithelial cells in the trachea, 0.03 in the large airways, and 0.02 in the small airways. In order to evaluate the ability of this method to determine changes in number of APUD cells, rats were exposed to diethylnitrosamine (DEN) and nitrogen dioxide (NO2), which have been reported to increase the number of airways APUD cells. The NO2 exposure was associated with a twofold increase in APUD cells of the trachea only without associated epithelial hyperplasia; DEN produced marked epithelial hyperplasia in the trachea and bronchi with a disproportionate increase in APUD cells in the bronchial epithelium only. The basis of this differential effect requires further study.

APUD Cells↗
PubMed1981

Benign disease of the anus, rectum and colon.

Benign diseases of the anus, rectum, and colon are common and in most instances simple to treat. However, there may be complications that are considered serious. The authors present examples of these diseases and emphasize pathological anatomy and practical surgical therapy.

Anus Diseases↗
PubMed1980

Histochemical properties of muscle fibres types and enzyme activities in skeletal muscles of Standardbred trotters of different ages.

Fibre characteristics and enzyme activities were determined for the gluteus, semitendinosus, vastus lateralis and triceps brachii muscles of 55 Standardbred trotters of different ages. Four fibre types (I, IIA, IIB, IIC) were demonstrated by histochemical staining of myofibrillar adenosine triphosphatase after preincubation at different pH values. Type II fibres predominated in all the muscles and the type IIA/IIB ratio was higher in horses over 5 years than in younger horses, except in the vastus in which the IIA/IIB ratio did not change with age. The vastus had the highest proportion of type IIA fibres and the semitendinosus the highest proportion of type IIB fibres. Histochemical demonstration of NADH dehydrogenase disclosed that almost 100 per cent of the type IIA and many of the type I and IIB fibres were medium-stained; the remaining type I fibres were darkly stained and the type IIB fibres lightly stained. In older horses more fibres were stained for NADH dehydrogenase. The activity of triosephosphate dehydrogenase decreased that that of 3-hydroxy-acyl-coA dehydrogenase and citrate synthase increased in all the muscles except the vastus with increasing age. The greatest increase in oxidative capacity occurred in the gluteus and triceps. Training, rather than age, was regarded as the factor inducing these changes. The results emphasise that histochemical data are only semiquantitative, and there are apparent discrepancies in the intensities of histochemical staining and the biochemical evaluation of various enzymes.

Adenosine Triphosphatases↗
PubMed1980

Health status of cable splicers with low-level exposure to lead: results of a clinical survey.

The results of a cross-sectional clinical field survey of 90 telephone cable splicers are presented. Despite the rare occurrence of clinically overt lead poisoning among cable splicers, the observed prevalence of symptoms was 29% for lead-associated central nervous system symptoms and 21% for gastrointestinal symptoms. These two groups of symptoms were directly related to zinc protoporphyrin (ZPP) levels but no relationship was found between them and blood lead concentrations. Only 5% of the workers had significantly elevated blood lead levels (greater than 40 microgram/100ml). Because of the intermittent lead exposure encountered in this trade, individuals were identified with "normal" blood lead levels associated with "elevated" zinc protoporphyrin concentrations, indicating the difference in biological significance between exposure-(blood lead) and biological-response tests (ZPP). Suggestion is made that both types of diagnostic tests be utilized in the medical surveillance of lead-exposured workers.

Adult↗
PubMed1979

Decrease in vital capacity in PCB-exposed workers in a capacitor manufacturing facility.

Pulmonary function was evaluated in 243 workers exposed to PCB in the manufacture of capacitors. Mean employment was greater than 15 years. Thirty-four of the workers (14%) were found to have a reduced Forced Vital Capacity (FVC less than 80% of Morris' predicted). Of the 34 with reduced FVC, 27 (80%) demonstrated a restrictive pattern of impairment (FEV1/FVC greater than 0.7). Only one of these 27 workers had an abnormal chest roentgenogram (greater than or equal to 1/0 by ILO UC Classification of Radiographs of Pneumoconioses). These findings are of interest in view of recent experimental data indicating the accumulation of PCBs and PCB metabolites in lung tissue (Brandt and Jansson). Restrictive spirometric impairment with no radiographic change is unusual in occupational exposure.

Adult↗
PubMed1979

Visual evoked potentials and the visuogram in multiple sclerosis.

Visual evoked potential (VEP) latency to a sinusoidal grating pattern was measured in each eye of 103 patients with multiple sclerosis (MS) and compared with results in a control group of 56 patients hospitalized for other neurological conditions. Of the 50 patients classified as having definite MS, 90% showed prolonged latency (over 131 msec) in one or both eyes. In each eye of 24 of the MS patients, psychophysical measurement of the detectability of grating patterns was obtained. This test was abnormal in 11 of 13 patients with definite MS, 3 of 4 with probable MS, and 5 of 7 with possible MS. There was no concordance between prolonged VEP latency and visual impairment as revealed by the psychophysical test. Apparently pathways determining VEP latency and spatial contrast detection may be unequally affected in MS.

Evoked Potentials↗
PubMed1978

Current status of skin substitutes.

In the current state of the art, viable human allograft is the best skin prosthesis available, but it leaves much to be desired. Characteristics of skin substitutes can be defined and measured, resulting in the rational approach to design and testing of synthetic skin substitutes. Thin silicone polymer and modified plastic membranes, collagen films, and adherent methacrylate polymer applied by a spray technique (Hydron) are the most promising materials at present.

Adhesiveness↗
PubMed1977

Evaluation of a psychiatric clerkship by videotape.

The authors used a videotape-based objective examination ingeneral psychiatry to assess the clinical competence of medical students who had completed their third-year clerkship. The test has been shown to be a reliable, valid measure of clinical competence. Subjective faculty grading related positively to test scores. Students on one ward had significantly lower overall test scores, with particularly low scores on clinical judgement questions. However, faculty grades for these students were not significantly different. This suggests that the faculty was unable to assess the relative efficacy of its own teaching. The test can provide objective assessment of student clinical competence and is a means of program evaluation.

Clinical Competence↗