Search PubMed⌕ Search

Biomedical subjects

M C Sheppard

Publications and source records attributed to M C Sheppard.

228 records · Page 13Linked to original sources
PubMed1980

Substance P release from rat hypothalamus and spinal cord.

A specific and sensitive radioimmunoassay for substance P has been developed to study the release of immunoreactive substance P from incubated rat hypothalamus and rat spinal cord in vitro. Release was significantly increased in the presence of two depolarizing stimuli (56 mM KCl and 75 microM veratrine) and was calcium-dependent. The released immunoreactive material diluted in parallel with synthetic substance P and showed close identity on Sephadex chromatography. A neuromodulator role for the peptide in the central nervous system is suggested.

Animals↗
PubMed1980

Tissue and serum somatostatin-like immunoreactivity in lean and obese Zucker rats.

Tissue and serum somatostatin levels were measured in genetically lean and obese Zucker rats. Immunoreactive somatostatin content was decreased in three central nervous system regions (hypothalamus, septum and preoptic area and thalamus) of obese rats but was increased in cerebral cortex. No differences were observed in antral or colonic somatostatin content but obese animals had significantly elevated pancreatic levels. Portal vein somatostatin-like immunoreactivity in contrast was significantly lower in obese rats. The widespread alterations in tissue and serum somatostatin-like immunoreactivity suggest either a diffuse abnormality of somatostatin physiology or a response to a generalised feature of the obese hyperinsulinaemic state.

Animals↗
PubMed1979

Ultracentrifugation evidence for a somatostatin-binding protein in serum.

Using a technique of high speed centrifugation of serum and a well validated immunoassay for the measurement of serum somatostatin-like immunoreactivity, we have demonstrated that somatostatin, unlike other peptide hormones, appears to sediment with large molecular weight proteins. When synthetic somatostatin of increasing concentration was incubated with serum prior to ultracentrifugation, a linear plot of concentration of somatostatin added against concentration sedimenting (or apparently bound to protein) revealed an association curve. These data provide further evidence for the existence of a serum-binding protein for somatostatin.

Adult↗
PubMed1977

Clinical picture of peptic ulceration diagnosed endoscopically.

Clinical features and laboratory data are presented for 100 patients with benign gastric ulceration and 150 patients with duodenal ulceration confirmed endoscopically in a district general hospital unit. Abdominal pain was the commonest indication for endoscopy, but one third of examinations were performed for acute gastrointestinal haemorrhage. Although the patients were selected by referral for endoscopy their clinical presentation, age, and sex distribution were similar to those reported in previous general surveys. There were no clinical features which clearly distinguished gastric from duodenal ulceration. However, of those with gastric ulceration younger patients more often had distal ulcers and presented with pain, while elderly subjects tended to have high lesser curve involvement and presented with haemorrhage. Moreover, all females presenting with haemorrhage were aged over 50 years, while 6% of males bleeding from gastric ulceration and 40% of males bleeding from duodenal ulceration were under this age. Anaemia when present, except in two premenopausal females, indicated either a recent acute gastrointestinal haemorrhage or a coexistent second diagnosis.

Adolescent↗
PubMedDate not supplied

Thyroid hormone receptor expression in the "sick euthyroid" syndrome.

To explore the hypothesis that alteration of T3 receptor expression may be an important mechanism controlling the tissue effects of thyroid hormones in the "sick euthyroid" syndrome, specific triiodothyronine (T3) receptor mRNAs were measured in tissues from normal subjects and from patients with liver disease, chronic renal failure, or with multiple organ failure on an intensive care unit (ICU). In all patient groups circulating free thyroxine and free T3 were reduced, while thyroid stimulating hormone remained normal. In patients with liver or renal disease, there were significant increases in levels of both alpha and beta T3 receptor mRNAs in peripheral mononuclear cells (PMNCs); in ICU patients there was a significant increase in beta mRNA. In patients with liver disease increases in T3 receptor mRNAs were not confined to PMNCs but were also found in liver biopsy specimens when levels were compared with those in normal donor liver. After liver transplantation, receptor mRNAs in PMNCs were similar to those in controls; likewise beta mRNA was similar in liver tissue to normal liver. There was, however, persistent elevation in alpha receptor mRNA. Increases in T3 receptor expression in non-thyroidal illness may be responsible for the maintenance of euthyroidism in the face of reduced levels of circulating thyroid hormones.

Adolescent↗
PubMedDate not supplied

The effect on mortality of low-dose insulin therapy for diabetic ketoacidosis.

The presentation, treatment, and outcome in 353 episodes of diabetic ketoacidosis have been examined to assess the effect of low-dose insulin therapy on mortality. There were 19 deaths during the period of study, with a mortality rate of 4.4% for patients treated with infrequent large doses of soluble insulin and 4.6% for patients treated with frequent intramuscular injections or continuous infusion of insulin. We conclude that in a center which practices an intensive care approach to the management of diabetic ketoacidosis, the use of a low-dose insulin regimen has not altered mortality.

Adolescent↗
PubMedDate not supplied

Differential growth response to oestrogen of premalignant and malignant colonic cell lines.

Epidemiological and experimental evidence support a role for sex steroid hormones in colorectal cancer. The aims of this study were to determine expression of oestrogen receptor in adenoma derived and carcinoma derived colonic epithelial cell lines, and to determine the in vitro effect of beta oestradiol on growth. Between 0.5-1.5 fmol/mg protein of oestrogen receptor was expressed in the colonic cell lines studied. mRNA for oestrogen receptor was also expressed. An adenoma derived cell line, AA/C1, demonstrated an increase in growth rate in response to beta oestradiol. The effect was density dependent. The cell line AA/C1/SB10, a chemically transformed derivative of AA/C1, did not respond to beta oestradiol. Adenoma derived and carcinoma derived colonic cell lines express oestrogen receptor. Oestrogen may have a trophic action in vivo on premalignant colonic epithelium.

Breast Neoplasms↗