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Biomedical subjects

D L Coleman

Publications and source records attributed to D L Coleman.

At least 163 records · Page 9Linked to original sources

Alteration of islet cell populations in spontaneously diabetic mice.

Endocrine-cell populations in the islets of Langerhans of mutant mice with a severe hypoinsulinemic diabetes (ob/ob or db/db on the C57BL/KsJ background) or with a mild hyperinsulinemic diabetes (ob/ob or db/db on the C57BL/6J background) were studied quantitatively by immunofluorescence and morphometry. In severely diabetic mice, islets presented a reduced proportion of insulin containing cells but increased glucagon-, somatostatin-, and pancreatic polypeptide (PP)-containing cells, as compared with islets of control (+/+) mice. An inverse change was observed in islets of mildly diabetic mice: islets were hypertrophic and composed mostly of insulin-containing cells, with decreased proportions of glucagon-, somatostatin-, and PP-containing cells. In both types of diabetic syndromes, the changes in cell populations induced a qualitative alteration of cellular interrelationships in the affected islets.

Animals↗

Genetic control of glucokinase activity in mice.

Inbred strains of mice were surveyed for liver glucokinase activity. Mice of all strains studied could be distributed into three groups with high, intermediate, and low levels of enzyme activity. Genetic analysis using crosses and backcrosses with prototype high (C3H/HeJ) and low (RF/J) strains revealed that glucokinase activity was controlled by a single gene. The name "glucokinase" and gene symbol Gk are suggested for this gene. The Gka allele designates the strain with high glucokinase activity, while Gkb represents the allele in the strain with the low enzyme activity. The interaction of fasting and diabetes on the activity of glucokinase in these two strains is described.

Animals↗

Plasma corticosterone concentrations in diabetic (db) mice.

Plasma corticosterone concentrations in diabetic (db) mice maintained on two different inbred backgrounds were found to be elevated significantly when compared to normal controls. These data are similar to that reported with the phenotypically similar obese (ob) mouse. These results suggest that the hyperadrenolcorticism is not related to the primary gene action of either gene but rather is a consequence of the development of the obesity-diabetes syndromes.

Animals↗

Laboratory animals exhibiting obesity and diabetes syndromes.

Spontaneous hyperglycemia, hyperinsulinemia and obesity are common features for at least one period of the lifetime in some strains of mice. Both genetic and environmental factors are involved in the pathogenesis of the diabetes-like syndrome, making these strains excellent models for studies in both obesity and diabetes-like states. The metabolic peculiarities can be due to a dominant gene, as for the yellow obese, or a single recessive gene, as in the obese and the diabetes mouse; or they can be of polygenic origin, as for the KK and the NZO mouse. However, the severity of the metabolic disorder is due to the interaction of the mutant genes iwth modifiers in the bat genes themselves. Studies on the pathophysiology and biochemistry of these animals have revealed interstrain differences, different patterns of development of the metabolic disorder, and different degrees of severity of the diabetes-like syndrome. Although the primary causes of the syndrome remain unclear in some strains, an involvement of hypothalamic feeding centers has been implicated.

Adipose Tissue↗

Platelet retention by albuminated glass and polystyrene beads.

Ex vivo platelet retention by albuminated glass and polystyrene beads has been evaluated as a function of flow rate, bead surface area, blood exposure time and albumin treatment. The stability of the albumin coatings as well as scanning electron microscopy of the various surfaces before and after blood exposure has also been included. Results indicate that platelet retention is sensitive to changes in the above parameters and that albumin pretreatment of different substrates can decrease platelet retention. This decrease is substrate dependent in that platelet retention is different for the albuminated glass and polystyrene substrates. Chemical analysis of the substrate materials by X-ray photoelectron spectroscopy (XPS) as well as bulk chemical analysis is also reported.

Animals↗

Stability of frozen solutions of cefazolin sodium.

The stability of frozen solutions of cefazolin sodium was investigated in nine commonly used diluents at concentrations of 1 g with 2.5 ml, 500 mg with 100 ml and 10 g with 45 ml in both glass and polyvinylchloride plastic containers. The diluents were: Water for Injection USP; 0.9% Sodium Chloride Injection USP; 5% Dextrose Injection USP (D5W); D5W with 0.02% sodium bicarbonate; D5W in Lactated Ringer's Injection USP; Lactated Ringer's Injection USP; Ionosol B in D5W; Normasol M in D5W; and Plasmalyte in D5W. Frozen cefazolin sodium solutions, containing Water for Injection USP, 5% Dextrose Inection USP or 0.9% Sodium Chloride Injection USP as the diluents, retained more than 90% of labeled potency for up to 26 weeks when frozen within one hour after reconstitution and held at -10 C or -20 C. Frozen cefazolin sodium solutions, made with other diluents, were stable for up to four weeks when frozen within one hour after reconstitution and held at -10 C.

Animals↗