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Biomedical subjects

G M Murphy

Publications and source records attributed to G M Murphy.

At least 253 records · Page 14Linked to original sources
PubMed1985

Volumetric asymmetry in the human striate cortex.

A sample of 31 serially sectioned human brains, in age from 33 weeks of gestation through 94 years, was examined for volumetric asymmetries in the striate cortex. The right striate cortex was found to be larger than the left in 24 of 31 cases. On the average, the right striate cortex was larger than the left by about 5%; this difference was statistically significant. Although past studies indicated that the posterior cerebrum is anatomically asymmetrical, no consistent pattern had been found, and no study had examined the actual volume of the striate cortex in the two hemispheres. The demonstration of asymmetries in the striate cortex is important because differences exist between the hemispheres in a wide range of perceptual and spatial skills related to vision. I suggest that the striate cortical asymmetry is related to the right hemisphere's superiority in visuospatial functioning.

Adolescent↗
PubMed1985

The human corpus striatum and dentate nucleus: volumetric analysis for hemispheric asymmetries, sex differences, and aging changes.

The corpus striatum and the dentate nucleus were examined for volumetric asymmetries, sex differences in volume, and for aging changes in volume in a sample of 27 human brains ranging in age from 281 days of gestation to 94 years of age. No statistically significant hemispheric asymmetries were found, and no sex differences in volume or in degree of hemispheric asymmetry were found. It was found that the volumes of the corpus striatum and the dentate nucleus decrease in relation to the volume of the whole hemisphere with aging, but the rate of decrease is different before than after sexual maturity. The significance of these findings is discussed in relation to lateralization of motor functioning, sex differences in the brain, and aging changes in the brain.

Adolescent↗
PubMed1985

Studies on the pathogenesis of bovine ephemeral fever in sentinel cattle. II. Haematological and biochemical data.

Twenty-two non-lactating dairy cattle from a sentinel herd previously described (St. George, 1985) were monitored daily during an outbreak of ephemeral fever. Nine developed clinical ephemeral fever between 25 December 1981 and 30 January 1982. There were no subclinical infections with bovine ephemeral fever virus in the group. There were, however, subclinical infections with CSIRO Village, Akabane, Aino, Tinaroo and Kimberley viruses as described by St. George et al. (1984). Six of the nine affected cattle showed a neutrophilia with a concurrent lymphopaenia on the day of pyrexia; however, the differential white cell profile had begun to change up to 24 h prior to leucocytosis. Serum carboxypeptidase values fell by 24 h following the febrile response. Plasma fibrinogen rose rapidly in all six cows. The peak concentration (15.6 +/- 2.70 g l-1) occurred 3 days after pyrexia with the highest individual increase being from 6.05 to 19.6 g l-1. Plasma fibrinogen levels remained elevated for at least 7 days. Serum calcium fell significantly during Day 1 of the disease, the mean decline being 0.22 +/- 0.08 mmol l-1. The greatest individual fall was from 2.33 to 1.92 mmol l-1. None of the affected cattle showed any compensatory change in serum magnesium. There was no change in the normal values of creatinine, urea, gamma-GT, AST and alkaline phosphatase. Bovine ephemeral fever virus was isolated from only four of the six cases, whereas specific antibody was detected in all cattle 3-4 days after recovery.

Animals↗
PubMed1985

Bile lipid secretion in obese and non-obese individuals with and without gallstones.

Biliary lipid secretion rates were measured in non-obese and obese individuals with and without cholesterol gallstones, using a steady-state, amino acid duodenal perfusion method. In addition, biliary lipid secretion rates were measured in five obese gallstone patients receiving high-dose chenodeoxycholic acid therapy (16-22 mg day-1 kg-1). Bile acid secretion rates in the non-obese patients with cholesterol gallstones (563 +/- SEM 70 mumol/h, n = 6) were significantly lower than in the non-obese controls (1078 +/- 210 mumol/h, n = 10, P less than 0.05), whereas cholesterol secretion rates were similar in the non-obese individuals with and without gallstones (51 +/- 7 and 42 +/- 4 mumol/h respectively). In the obese, both with and without gallstones, the major abnormality was hypersecretion of cholesterol (107 +/- 7 mumol/h, n = 7, and 81 +/- 15 mumol/h, n = 7, respectively). Both these values were significantly greater than those in the non-obese controls (P less than 0.01-0.02). Biliary cholesterol secretion rates correlated significantly with bile acid secretion rates but, for every mole of bile acid secreted, the obese secreted more cholesterol than the non-obese. Chenodeoxycholic acid treatment lowered biliary cholesterol saturation in obese gallstone patients by reducing biliary cholesterol secretion. These results suggest that there are two major types of defect in biliary lipid secretion in gallstone patients: reduced biliary bile acid secretion in non-obese gallstone patients and excessive biliary cholesterol secretion in the obese.

Adult↗
PubMed1985

Hormones and polyamines in intestinal and pancreatic adaptation.

The evidence for and against an enteropancreatic trophic axis is reviewed. Luminal nutrition is essential for the maintenance of normal intestinal mucosal, and exocrine pancreatic, structure and function. Exclusion of luminal nutrition leads to mucosal hypoplasia and hypofunction with similar changes in the pancreas. The trophic effect of luminal nutrition may be mediated through the release of regulatory peptides with endocrine or paracrine effects. Enteroglucagon is the strongest candidate for the role of 'enterotrophin' while cholecystokinin (CCK) markedly influences pancreatic growth. Thus, CCK not only stimulates exocrine pancreatic secretion but makes acinar cells divide and the pancreas grow. The cellular mechanisms whereby trophic peptides influence normal and adaptive growth are also discussed with emphasis on polyamines (putrescine, spermidine and spermine) and the key enzymes controlling their synthesis (ornithine decarboxylase; ODC) and degradation (diamine oxidase; DAO). When polyamine synthesis is blocked with the ODC inhibitor, difluoromethyl ornithine (DFMO), the adaptive intestinal hyperplasia of pancreatico-biliary diversion is either inhibited or completely prevented. A proposed sequence of events might be as follows: luminal nutrients, particularly long-chain fats, reach the ileum and colon and stimulate increased enteroglucagon release. Enteroglucagon binds to cell receptors and triggers an intracellular cascade involving ODC and the polyamines, which, in turn, stimulate RNA polymerase, DNA, RNA and protein synthesis, cell division, and adaptive tissue growth.

Adaptation, Physiological↗
PubMed1985

Late-onset erythropoietic protoporphyria with unusual cutaneous features.

A 68-year-old man with apparently light-exacerbated erythematous cutaneous plaques on his face and on the dorsa of his hands was found to have late-onset erythropoietic protoporphyria, diabetes mellitus, and hyperlipidemia. Extensive deposits of material that stained with periodic acid-Schiff were present in the lesional dermis. Monospecific antibody studies showed this material to be mainly type IV collagen. These findings strongly suggest that the lesions are a manifestation of erythropoietic protoporphyria. The late onset and asymptomatic unusual cutaneous lesions appear to be a new presentation of the disease.

Aged↗
PubMed1984

Serological and biochemical factors in bovine ephemeral fever.

Clinical signs of ephemeral fever, which were observed in individual cattle during two successive epidemics in 1973 and 1976, were related to biochemical, cellular and serological changes in the blood. The rise in peripheral blood neutrophil counts in samples collected from 12 sentinel cattle on a daily basis before, during and after natural disease in the two epidemics to mean peaks of 9.6-12.5 X 10(9) per litre, and fall in counts of lymphocytes to a trough of 5-7 X 10(9) per litre was found to occur on the same day as the fever peak. A fall in serum calcium levels from a normal mean of 2.55 mmol/l to 2.0 mmol/l occurred on the day clinical signs were most pronounced. Serum magnesium levels were affected to only a minor degree. Plasma fibrinogen rose from a normal mean of 5.0 milligrams to a peak of 18 milligrams on the second day of disease and fell towards normal in the week after recovery. Neutralizing antibodies to bovine ephemeral fever virus were detected up to 63 days prior to clinical disease, and the rise of antibody after recovery was secondary in pattern. Serological evidence of a prior infection with an antigenically related virus, Kimberley virus, was found in these animals. In more severe clinical cases of ephemeral fever serum calcium levels were as low as 1.95 mmol/l. Treatment of cattle showing clinical signs of the disease with phenylbutazone and calcium borogluconate was favourable.

Animals↗
PubMed1984

Autonomic function in cholinergic urticaria and atopic eczema.

Autonomic function in patients with cholinergic urticaria and atopic eczema was compared with that in patients with chronic idiopathic urticaria and non-atopic allergic contact dermatitis, respectively. Forty-nine patients were studied. The following specific tests of sympathetic and parasympathetic function were used to assess the integrity of autonomic control: pupillary reflex amplitude in response to pulsed light stimulation and response to topical arecoline hydrobromide (parasympathetic); the speed of pupillary dilatation following a large light reflex (sympathetic); pupillary resting diameter (sympathetic and parasympathetic); sweat gland response to forearm intradermal injection of acetylcholine chloride; and the effect of postural change and deep breathing on blood pressure and heart rate (sinus arrhythmia indicating parasympathetic function). No significant difference in autonomic function was found between the four groups of patients.

Acetylcholine↗
PubMed1984

Comparison of the effects of medium and long chain triglyceride containing liquid meals on gall bladder and small intestinal function in normal man.

We investigated the effects of medium (MCT) and long (LCT) chain triglyceride test meals on gall bladder contraction (using ultrasonography) and small intestinal bile acid concentrations and ileal flow rates (using intubation techniques) in normal individuals. Comparing the effects of ingesting medium chain triglyceride and long chain triglyceride meals, the gall bladder volume was reduced by 23.4 +/- 33.6% and 59.0 +/- 17.1% respectively (mean +/- SD, p less than 0.01, n = 13), the jejunal bile acid concentrations increased significantly only after the ingestion of long chain triglyceride (p less than 0.05, n = 5), while the volume of the postprandial jejunal contents was not significantly different (540 +/- 150, 522 +/- 169 ml, medium chain triglyceride vs long chain triglyceride, p = 0.2, n = 5). The postprandial colonic inflow was 48.5 +/- 12.5 and 123.4 +/- 35.2 ml/h (medium chain triglyceride vs long chain triglyceride, p less than 0.01, n = 5). Thus medium chain triglyceride, compared with long chain triglyceride, produces a smaller input of bile acids into the small intestine and a smaller volume of fluid delivered to the colon. These observations may be relevant to the beneficial effects of medium chain triglyceride substitution for long chain triglyceride in the treatment of diarrhoea in patients with small intestinal disease.

Adult↗
PubMed1984

Colorimetric enzymatic measurement of serum total 3 alpha-hydroxy bile acid concentrations without extraction.

A new method for the simpler colorimetric assay of serum total 3 alpha-hydroxy bile acid concentrations without prior extraction has been investigated. The lowest concentration that could be reliably measured was 3 mumol/l and the results obtained were in agreement with those obtained using extraction and the spectrofluorimetric enzymatic assay (y = 1.007x - 1.86, r = 0.99, n = 36). Results for 20 normal sera collected after an overnight fast were 6.2 +/- 5.1 mumol/l (mean +/- SD) and in 20 normal plasma randomly collected were 4.9 +/- 4.2 mumol/l. This new assay is comparable in specificity and sensitivity to the older spectrofluorimetric enzymatic assays and convenient for routine use.

3-Hydroxysteroid Dehydrogenases↗
PubMed1984

Influence of gallstones and ursodeoxycholic acid therapy on gallbladder emptying.

Altered gallbladder motility could predispose to, or result from, gallstone formation and could also explain the alleged relief of biliary colic seen during bile acid therapy. Therefore, in 14 controls, 25 patients with radiolucent gallstones, and 14 patients with radiopaque gallstones, we used two techniques to measure gallbladder contraction--radionuclide imaging and real-time ultrasound--in response to one of two stimuli--a Lundh meal or intravenous cholecystokinin-octapeptide. Using the radionuclide technique, postprandial gallbladder emptying (t1/2) was prolonged (p less than 0.01) both in patients with radiopaque (26.7 +/- 3.1 min, mean +/- SEM) and radiolucent (21.7 +/- 3.1) gallstones when compared with controls (10.2 +/- 1.5). In patients with radiolucent stones, the t1/2 of gallbladder emptying became further prolonged (p less than 0.05) after 1 mo of therapy with 8-10 mg/kg body wt X day of ursodeoxycholic acid, to 32.1 +/- 4.4 min. A similar pattern of results was seen after cholecystokinin-octapeptide and also with real-time ultrasound. Thus, after both stimuli and using two independent techniques, gallbladder contraction was reduced in patients with gallstones. The slower and less complete gallbladder emptying with ursotherapy might explain the reduction in biliary colic noted during treatment.

Adult↗
PubMed1983

Persisting cholinergic erythema: a variant of cholinergic urticaria.

A new variant of cholinergic urticaria is described. Four patients each had a similar persistent macular skin rash distributed maximally over the upper limbs and upper trunk. Though the rash was persistent, individual macules were of short duration but new macules continually appeared at adjacent sites. Exercise and hot baths exacerbated pruritus and provoked lesions in previously unaffected areas. Topically applied benzoyl scopolamine blocked the appearance of the lesions after challenge. Tests of cholinergic function were normal, apart from an exaggerated pupillary response to arecoline in one patient.

Acetylcholine↗
PubMed1983

Effect of colonic perfusion with sulfated and nonsulfated bile acids on mucosal structure and function in the rat.

A single-pass perfusion system was used in conscious restrained rats to measure changes in water and electrolyte transport and in protein and deoxyribonucleic acid output after perfusing 5-15-mM solutions of sulfated or nonsulfated bile acids through the colon. Perfusion with 5 mM nonsulfated deoxycholic acid or chenodeoxycholic acid changed net water and sodium absorption to net secretion, provoked marked increases in protein and DNA output into the perfusion effluent, and caused microscopic mucosal damage. In contrast, perfusion with 5 and 15 mM sulfated deoxycholic acid or with 5 mM sulfated chenodeoxycholic acid had no effect on water and electrolyte transport and caused only modest changes in protein and DNA output. To see whether or not sulfated bile acid could prevent the effect of its nonsulfated parent compound on colonic structure and function, perfusion with a mixture of 5 mM nonsulfated and 10 mM sulfated deoxycholic acid was performed. This produced net secretion of water and sodium together with less marked increases of protein and deoxyribonucleic acid output and less pronounced microscopic mucosal damage than was seen after 5 mM nonsulfated deoxycholic acid alone. Finally, 5 mM nonsulfated cholic acid had no effect on water or sodium transport, but 5 mM sulfated cholic acid, with one alpha-hydroxyl group masked and two alpha-hydroxyl groups "exposed," reduced water transport. These results suggest that sulfation prevents the cathartic effect of alpha-dihydroxyl bile acids in the colon.

Animals↗