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Biomedical subjects

L Sampson

Publications and source records attributed to L Sampson.

44 records · Page 3Linked to original sources

The HLA B w4/w6 diallelic system in Graves' disease.

We studied the diallelic system HLA--Bw4/w6 in patients with Graves' disease and control subjects. Twenty-one out of the 22 patients with Graves' disease were found to be HLA--Bw6 positive and 16 of these were homozygous, contrasted with 28 and 9 out of 34 controls, respectively. HLA--Bw6 positivity results in a relative risk for Graves' disease of 3.27; homozygosity for that allele further increases the risk to 7.4. It is possible that the increased risk attached to HLA--Bw6 is secondary to the increase in HLA--B8 previously described in Graves' disease.

Alleles↗

Studies on gluconeogenesis, protein synthesis and cyclic AMP levels in isolated hepatocytes from alloxan diabetic rats.

Alloxan diabetic rats maintained on protamine zinc insulin for two weeks were used for these studies. Hepatocytes were isolated from these rats at various time intervals after withdrawal of insulin (0, 48, 72 and 96 hr). Gluconeogenesis with various concentrations of lactate and fructose was studied. Both lactate and fructose stimulated gluconeogenesis and showed progressive increases in glucose production up to 72 hr after the insulin withdrawal. Glucose production decreased at 96 hr. Protein synthesis in isolated hepatocytes from diabetic liver cells, as measured by the incorporation of radioactive isoleucine, valine and phenylalanine into protein, showed a decrease (5- to 6-fold) with time after insulin withdrawal. Glucagon (10(-6)M) alone increased cyclic AMP levels 10-fold in liver cells, in isolated cells from rats maintained on insulin (0 hr) or from rats withdrawn from insulin for 48 hr. The ability of glucagon to elevate cyclic AMP levels in isolated diabetic liver cells decreases 72 hr following insulin withdrawal.

Animals↗

Studies on gluconeogenesis and stimulation of glycogen and protein synthesis in isolated hepatocytes in alloxan diabetic, normal fed and fasted animals.

Hepatocytes were isolated by collagenase in vitro perfusion technique. Net glucose production in isolated hepatocytes obtained from fed, fasted and alloxan diabetic rats was studied. Net glucose production from alanine, pyruvate and fructose was increased by 2-5 fold in isolated hepatocytes obtained from fasted and alloxan diabetic rats. Similar increases in the incorporation of 14C-bicarbonate into glucose was also observed. Net glucose production in isolated hepatocytes was also compared to other in vitro preparations. Net glucose production was much higher (2-5 fold) in isolated hepatocytes than that reported previously for liver slices or perfused liver. Studies on glycogen and protein synthesis show a 2 fold stimulation in the incorporation of 1-14C-glucoase into glycogen and U-14C-leucine into protein by the addition of 100 muU of insulin to isolated hepatocytes.

Animals↗