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Biomedical subjects

C J Bailey

Publications and source records attributed to C J Bailey.

228 records · Page 13Linked to original sources
PubMed1969

The subunit structure of jack-bean urease.

1. Urease of specific activity 160-180 Sumner units/g. (Sumner, 1951) was purified from jack-bean meal. The preparation was pure on the basis of polyacryl-amide-gel electrophoresis and N-terminal studies. 2. By using both the 1-fluoro-2,4-dinitrobenzene method and the phenyl isothiocyanate method a single N-terminal methionine residue was found. 3. A single C-terminal sequence -Tyr-Leu-Phe was found by studies with carboxypeptidase A, carboxypeptidase B and hydrazinolysis. 4. N-Bromosuccinimide cleavage showed that five unique tryptophan sequences were present: Trp-Ala, Trp-Glu, Trp-Gly, Trp-Met and Trp-Arg. 5. Polyacrylamide-gel electrophoresis in sodium dodecyl sulphate showed that urease had a subunit molecular weight of 76000. 6. The yield of N- and C-terminal amino acids, the number of tryptic peptides and tryptophan sequences and the above polyacrylamide-gel electrophoretic measurement all suggest that urease contains a single structural subunit of molecular weight 75000.

Amino Acid Sequence↗
PubMedDate not supplied

Evaluation of traditional plant treatments for diabetes: studies in streptozotocin diabetic mice.

Seven plants and a herbal mixture used for traditional treatment of diabetes were studied in streptozotocin diabetic mice. The treatments were supplied as 6.25% by weight of the diet for 9 days. Consumption of diets containing bearberry (Arctostaphylos uva-ursi), golden seal (Hydrastis canadensis), mistletoe (Viscum album) and tarragon (Artemisia dracunculus) significantly reduced the hyperphagia and polydipsia associated with streptozotocin diabetes, but bayberry (Cinnamomum tamala), meadowsweet (Filipendula ulmaria), senna (Cassia occidentalis) and the herbal mixture did not alter these parameters. Bearberry, mistletoe and tarragon retarded the body weight loss but none of the eight treatments significantly altered plasma glucose or insulin concentrations. These studies suggest that bearberry, golden seal, mistletoe and tarragon may counter some of the symptoms of streptozotocin diabetes without, however, affecting glycemic control.

Animals↗
PubMedDate not supplied

Guar and gastric emptying in non-insulin dependent diabetes.

A gamma camera was used to measure gastric emptying in 10 non-insulin dependent diabetics and 10 control subjects and after a breakfast meal of porridge labelled with 113mIn. In the diabetics there was a more rapid early phase and a more prolonged later phase of gastric emptying compared with controls. Incorporation of 10 g guar with the meal prolonged the later phase of gastric emptying in controls. However, guar did not significantly alter gastric emptying in the diabetics, although postprandial plasma glucose concentrations were reduced. The study demonstrates abnormalities of both the early and later phases of gastric emptying in an unselected group of non-insulin dependent diabetics. Guar reduced plasma glucose concentrations without affecting gastric emptying in these patients.

Adult↗
PubMedDate not supplied

POMC-derived peptides in the neuromuscular system of streptozotocin-diabetic mice.

Immunoreactivity for beta-endorphin and alpha-MSH/ACTH was demonstrated in intramuscular nerves in soleus, extensor digitorum longus, and diaphragm muscles of normal and streptozotocin-diabetic mice. There was a higher incidence of immunoreactive nerves in the muscles of the diabetic mice. Specific binding for [125I]ACTH was detected in a proportion of the muscle fibers, using autoradiography. There were significantly more fibers with specific [125I]beta-endorphin sites and specific [125]ACTH sites in some muscles in the diabetic mice. The increased expression of POMC-derived peptides and their receptors in the neuromuscular system of streptozotocin-diabetic mice may indicate early neuropathic change.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Reversal of diabetes by syngeneic transplantation of a radiation-induced rat insulinoma.

The growth and metabolic effects of a radiation-induced rat insulinoma were examined after subcutaneous subscapular transplantation into normal and streptozotocin diabetic NEDH rats. Streptozotocin diabetic rats exhibited hyperglycaemia, hypoinsulinaemia, impaired glucose tolerance without an insulin response, polyuria, polydipsia, hyperphagia and weight loss. Transplantation of tumour fragments gradually improved the physical and metabolic state over the following 3 weeks. Coincident with a progressive rise in plasma insulin between 10 and 17 days, the diabetic rats gained weight and reduced their food intake. The rats remained hyperglycaemic during this time, but developed hypoglycaemia with marked hyperinsulinaemia by 24 days. Furthermore, plasma glucose and insulin concentrations were not increased by an intraperitoneal glucose challenge, indicating greatly accelerated glucose clearance. Both the streptozotocin-treated and normal insulinoma-bearing rats incurred a fatal hypoglycaemic coma by 28-33 days after transplantation. Final body weights, tumour weights and concentrations of glucose and insulin were similar in the two groups. This study demonstrates reversal of streptozotocin diabetes by insulinoma transplantation. The hyperglycaemia and the accompanying diabetic environment did not modify tumour growth and development.

Adenoma, Islet Cell↗
PubMedDate not supplied

Localization of the gene for familial adenomatous polyposis on chromosome 5.

Colorectal cancer is the second most common cancer in the United Kingdom and other developed countries in the West. Although it is usually not familial, there is a rare dominantly inherited susceptibility to colon cancer, familial adenomatous polyposis (FAP; also often previously called familial polyposis coli). During adolescence affected individuals develop from a few hundred to over a thousand adenomatous polyps in their large bowel. These are sufficiently likely to give rise to adenocarcinomas to make prophylactic removal of the colon usual in diagnosed FAP individuals. Adenomas may occur elsewhere in the gastrointestinal tract and the condition is often associated with other extracolonic lesions, such as epidermoid cysts, jaw osteomata and fibrous desmoid tumours. Adenomata have been suggested to be precancerous states for most colorectal tumours. Knudson has suggested that the mutation for a dominantly inherited cancer susceptibility may be the first step in a recessive change in the tumour cells, and that the same gene may be involved in both familial and non-familial cases of a given tumour. Following up a case report of an interstitial deletion of chromosome 5 in a mentally retarded individual with multiple developmental abnormalities and FAP, we have now shown that the FAP gene is on chromosome 5, most probably near bands 5q21-q22.

Adenocarcinoma↗
PubMedDate not supplied

Metformin potentiates the antigluconeogenic action of insulin.

The interaction of metformin and insulin in the control of hepatic gluconeogenesis was examined in isolated hepatocytes from 48h starved rats using lactate (10(-2) mol/l) with pyruvate (10(-3) mol/l) as substrate. During 1 h incubations in the absence of added insulin, 10(-2) and 10(-3) mol/l metformin reduced gluconeogenesis by 65% and 59% respectively, but lower concentrations of metformin were not effective. Insulin alone (10(-6)-10(-8) mol/l) reduced (37%-16%) gluconeogenesis. The effect of insulin was enhanced (further reductions of 11%-24%) by 5 x 10(-4) mol/l metformin, although this concentration of metformin was not effective in the absence of insulin. At lower insulin concentrations (10(-9) and 10(-10) mol/l) which did not significantly affect gluconeogenesis alone, 5 x 10(-4) mol/l metformin decreased gluconeogenesis (32% and 28% respectively). At 10(-10) mol/l insulin, metformin concentrations of 10(-3)-10(-7) mol/l decreased gluconeogenesis by 60-20%. The results suggest that therapeutic concentrations of metformin may act synergistically with physiological concentrations of insulin to suppress hepatic gluconeogenesis.

Animals↗