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Biomedical subjects

G Kay

Publications and source records attributed to G Kay.

At least 55 records · Page 3Linked to original sources
PubMed1989

Blood constituent responses of cattle to herding.

Blood was obtained over a period of 20 minutes by remote controlled procedures from cattle while they were herded. Samples were analysed for catecholamines, cortisol, haematocrit, total lipid, glucose and lactate. The results show that the response to a given stressor is specific and suggest that multiple stressors may not necessarily result in additive effects.

Animals↗
PubMed1987

Drug deprivation and reinforcement by diazepam in a dependent population.

Individuals who were using therapeutic doses (approximately 15 mg diazepam or its equivalent daily) of a benzodiazepine persistently and wished to attempt to stop were recruited into a study offering a medically supported outpatient behavioral treatment with a goal of abstinence. All subjects received the same behavioral treatment that emphasized the development of strategies for coping with abstinence and alternatives to benzodiazepines as a coping mechanism. The goal of abstinence was to be achieved within approximately 8 weeks by means of gradual tapering of the daily dose. Some subjects (Group D, n = 23) were randomly assigned to a condition in which their dose was to be tapered on a regime of active diazepam. Others (Group P, n = 19) were switched to placebo at the first treatment session and "tapered" from this pharmacologically inert substitute for diazepam. Supplies of tablets of each preparation were provided by the experimenters, and subjects were specifically requested to use only those tablets. The principal dependent variable was "supplementation", or use of a benzodiazepine other than that specifically authorized by the therapist. Supplementation was detected by measures of plasma benzodiazepine levels as compared to levels predicted if there had been strict compliance with the therapeutic regime. These comparisons were made by two expert judges who were blind to the subjects' experimental assignment. Self-report of supplementation was also obtained. Plasma level determinations indicated a significantly greater frequency of supplementation (84% versus 33% of subjects) for subjects in Group P.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Inhibition of sterol and DNA synthesis in peripheral blood lymphocytes by AY9944.

The effect of the inhibitor of cholesterol synthesis AY9944 on DNA synthesis was tested in phytohemagglutinin stimulated lymphocytes incubated in delipidated serum. AY9944 caused a decrease in cholesterol synthesis from [14C] acetate and an accummulation of [14C] 7-dehydrocholesterol. This inhibition of cholesterol synthesis resulted in an inhibition of DNA synthesis in a dose related manner. Inhibition could be partly reversed by added lipoprotein. Inhibition of DNA synthesis occurred if AY9944 was added at the early stages of blast transformation but not when the response was well established. These findings suggest that some endogenous cholesterol synthesis may be required for the complete phytohemagglutinin stimulation of lymphocytes.

Cholesterol↗
PubMed1982

Cross-reactions among carbonic anhydrases I, II, and III studied by binding tests and with monoclonal antibodies.

Cross-reactions among carbonic anhydrases (CAs) I, II, and III were studied using a variety of antisera: (1) a rabbit antiserum to bovine CA III, (2) mouse antisera to human CA I, CA II, and CA III; and (3) five monoclonal antibodies prepared by the hybridoma technique using splenocytes from a mouse immunized with human CAs I and II and bovine CA III. Cross-reactions between CAs were readily found by binding assays using these antisera. Human CA I, but not human CA II, inhibited the reaction of the rabbit anti-CA III with its homologous antigen. Mouse antisera to CA I or CA III bound the homologous I or II with nearly as great efficiency as the autologous isozyme and sometimes weakly bound CA III. Mouse antisera to CA III frequently bound CA I or II. These cross-reactions were confirmed by the first use of hybridoma-prepared, monoclonal antibodies to CAs. The mouse monoclonal antibodies to CA isozymes varied in the amount of cross-reactivity among I, III, and III: at one extreme, one monoclonal was highly specific for the autologous CA III; at the other extreme, one monoclonal weakly reacted with some examples of CSs I, II, and III.

Animals↗
PubMed1982

The pancreolauryl test. A method of assessing the combined functional efficacy of pancreatic esterase and bile salts in vivo?

The pancreolauryl test is marketed as a tubeless test of pancreatic function based on the specific splitting by pancreatic esterase of orally administered fluorescein dilaurate. We have evaluated the test in 50 patients, all of whom had at least one other pancreatic function test (secretin-pancreozymin, Lundh, BT PABA/14C index). The sensitivity of the pancreolauryl test was 75% if equivocal results (T/K 20-30) were excluded and 77% if the equivocal results were included amongst the abnormal results - figures which were similar to those obtained for the other three function tests. However, the specificity of the pancreolauryl test was 60% if equivocal results were excluded, decreasing to only 39% if equivocal results were considered to be abnormal. The false-positive tests chiefly occurred in patients who had previously undergone gastric or biliary by-pass, or vagotomy and cholecystectomy (BT PABA/14C test normal). These data, and the known dependence of esterase activity on bile salts, suggest that the pancreolauryl test assesses the combined functional efficacy of secreted esterase and bile salts. Despite the test's high sensitivity, its low specificity makes it unreliable as a test of pancreatic function per se. The pancreolauryl test may be particularly useful in evaluating patients with bile-pancreatic juice admixture problems.

Bile Acids and Salts↗
PubMed1981

Intestinal alkaline phosphatase in bile: evidence for an enterohepatic circulation.

The isoenzyme characteristics of alkaline phosphatase in human bile obtained from patients with gallstones have been determined by means of electrophoresis on polyacrylamide gel, both before and after preincubation with neuraminidase, and also by means of inhibition tests with heat, urea, and L-phenylalanine. Bile alkaline phosphatase is shown to be partly secreted by the liver cell, but partly derived from the small intestine. The presence of small-intestinal alkaline phosphatase in bile implies an enterohepatic circulation of this high molecular weight glycoprotein. The significance of this finding is discussed in relation to the mechanism whereby large protein molecules may pass across the plasma membrane of the liver cell.

Alkaline Phosphatase↗
PubMed1979

Testicular function in patients with spinal cord damage.

Vaying degrees of testicular dysfunction are found in men with traumatic spinal cord damage. Eighteen paraplegic men have been studied and the gonadotropin response to luteinizing hormone-releasing hormone (LRH) measured. Basal serum testosterone estimations were made and in eight of the patients testicular testosterone reserve was assessed by the testosterone response to human chorionic gonadotropin (HCG). Testicular biopsies were performed in seven cases. In three of these patients, the testicular biopsies were abnormal. Five of the patients had elevated Follicle stimulating hormone levels and abnormalities of Luteinizing hormone kinetics were found in the same five patients. There was no significant difference between the plasma testosterone levels of the paraplegic patients when compared to the control group. In all the patients tested, there was an adequate testosterone reserve, and this included the three patients with the abnormal testicular biopsies. No relationship was found between the level of cord lesion and any of the hormonal parameters measured. This study confirms the primary nature of the seminiferous tubular damage which occurs in some patients with paraplegia.

Adult↗
PubMed1979

The relationship between marrow iron stores, plasma ferritin concentrations and iron absorption.

The percentage absorption from a 3 mg dose of ferrous iron was measured in 50 subjects with iron stores that varied over a wide range. Iron status was assessed by a number of measurements, including the haemoglobin concentration, the plasma iron concentration, the total iron-binding capacity, the plasma ferritin concentration and the concentration of non-haem iron in the bone marrow. There were good inverse correlations between the log percentage iron absorption and both the log marrow non-haem iron concentration (r -0.94; P less than 0.001) and the log plasma ferritin concentration (r -0.78; P less than 0.001). In addition, there was a positive ferritin concentration (r +0.84; P less than 0.001). These results suggest that reticuloendothelial iron stores represent an important determinant of iron absorption and that their size can be guaged from the plasma ferritin concentration.

Anemia↗
PubMed1979

The effect of pentagastrin (I.C.I. 50, 123) on peptic secretion in man.

1. We have studied the peptic responses of the intact human stomach to stimulation by doses of pentagastrin which elicit a maximal acid response.2. In twelve patients an intramuscular injection of pentagastrin (6 mug/kg) was followed by a prompt increase in acid output which attained a peak value eight times higher than the basal value in the period 15-30 min after stimulation. The pattern of the peptic response was similar, but the peak output of pepsin was only three times the output in unstimulated juice.3. In ten subjects the acid and peptic responses to I.V. infusion of pentagastrin (1.2 mug/kg per hr) were studied using a gastric perfusion technique with (14)C-labelled polyethylene glycol as non-absorbable marker. In seven of these ten subjects the pH of duodenal contents exceeded 6, and less than 0.5 m-mole HCl per 15 min entered the duodenum throughout the tests. In this subgroup pentagastrin evoked a strong acid response but no peptic response.4. In three subjects the pH of duodenal juice was less than 5.5 at times when more than 1 m-mole HCl per 15 min entered the duodenum. The acid response to pentagastrin differed considerably in the three subjects, but in each individual the output of pepsin increased each time an excess of HCl entered the duodenum.5. Since pentagastrin infused in a dose which maximally stimulates acid did not significantly increase the output of pepsin provided no HCl entered the duodenum we conclude that pentagastrin does not stimulate the secretion of pepsin in man. The transient insignificant peptic response to pentagastrin infusions, and the small but significant response to bolus injections of pentagastrin, can be explained as a wash-out phenomenon.

Gastric Juice↗
PubMed1978

Oestrogen receptors in tumours of breast cancer patients.

Oestrogen receptors were measured in the cytoplasmic fraction of tumours from patients with breast cancer. Receptors were detected in 48% of patients, and 52% showed no receptors. A follow-up study of a small group of patients on hormone therapy is reported.

Breast Neoplasms↗
PubMed1978

Pancreatic enzymes in human duodenal juice--a comparison of responses in secretin pancreozymin and Lundh Borgström tests.

We have compared the concentrations and total outputs of trypsin, amylase, and lipase secreted into the duodenum during secretin pancreozymin and Lundh Borgström tests in order to assess the relative intensity of pancreatic stimulation provided by these means. The mean concentration of trypsin, and the mean 10 minute total output of trypsin, amylase, and lipase after the meal (though less than the peak post-prandial responses) were equal to the respective peak enzyme responses after intravenous injection of 2 Crick Harper Raper units per kg of secretin Boots; and after intravenous injection of 2 Crick Harper Raper units per kg of pancreozymin Boots.

Amylases↗