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Biomedical subjects

J Stocks

Publications and source records attributed to J Stocks.

At least 127 records · Page 7Linked to original sources

DNA polymorphisms at the lipoprotein lipase gene: associations in normal and hypertriglyceridaemic subjects.

Lipoprotein lipase is a rate determining enzyme for the removal of triglyceride-rich lipoproteins from the blood stream. We examined whether genetic variation at the lipoprotein lipase gene locus was related to the fasting plasma level of triglycerides in both a normal and hypertriglyceridaemic population. Two restriction fragment length polymorphisms revealed by the enzymes PvuII and HindIII generated alleles designated H1, 17.5 kb;H2, 8.7 kb;P1, 7.0 kb;P2, 4.4 and 2.5 kb, respectively. These were studied in 46 Caucasian hypertriglyceridaemic subjects in comparison with 86 normolipidaemic controls. The respective allelic frequencies were H1 0.211, H2 0.789 and H1 0.414, H2 0.586 (p less than 0.01). Similar differences in allelic frequencies were found in a smaller group of Japanese hypertriglyceridaemic subjects (n = 29) compared to Japanese controls (n = 41, p less than 0.01). Ninety-three healthy Caucasians were genotyped for both polymorphic sites to relate to levels of plasma triglyceride. We found that individuals with genotype P1P1 had fasting triglyceride levels of 0.96 +/- 0.31 mmol/l (n = 20) compared to genotype P2P2 with levels of 1.31 +/- 0.66 mmol/l (n = 30, p less than 0.02); heterozygous subjects (P1P2) had intermediate levels of plasma triglyceride (1.15 +/- 0.46 mmol/l, n = 43). The HindIII alleles were not significantly associated with variation in levels of plasma triglyceride, cholesterol, or HDL-cholesterol. We conclude that DNA variations at, or around, the lipoprotein lipase gene may constitute genetic determinants for both the population variation in plasma triglyceride levels as well as for the common metabolic disorder of primary hypertriglyceridaemia.

DNA↗

Total respiratory compliance during anaesthesia in infants and young children.

The multiple occlusion technique was used to study the effects of paralysis on ventilatory mechanics during anaesthesia. Total respiratory compliance (Crs) was measured during spontaneous breathing and following neuromuscular block with controlled ventilation in 23 infants. There was marked variation in response to paralysis: some infants demonstrated no change in Crs between the two states; others had values of Crs which were significantly higher during paralysis with controlled ventilation than during spontaneous breathing. A possible cause of these differences may be the type of controlled ventilation given during paralysis, with tidal volume directly influencing values of Crs obtained. The results of this study suggest that values of Crs obtained during spontaneous breathing and paralysis should not be used interchangeably until further studies have been performed to assess factors influencing Crs during controlled ventilation.

Anesthesia, General↗

A DNA polymorphism of the apolipoprotein C-III gene in extracoronary atherosclerosis.

1. A genetic polymorphism of apolipoprotein (apo) C-III was studied in 49 Caucasian patients with extracoronary atherosclerosis demonstrated by angiography. 2. Twelve patients (24%) possessed an uncommon allelic variant of the apo A-I/C-III gene cluster compared with two (4%) in 50 healthy controls (P less than 0.01). 3. Of 27 patients with carotid atherosclerosis, 22% had the uncommon genotype (P less than 0.02), and in aorto-femoral atherosclerosis (n = 22) 27% possessed the uncommon variant (P less than 0.01). 4. When normotriglyceridaemic subgroups (n = 32) with arterial disease were studied the difference in genotype frequencies persisted, 22% having the uncommon allele (P less than 0.01), suggesting that such genetic variants have effects independent of circulating levels of plasma lipids.

Alleles↗

Hypertriglyceridaemia and diabetes mellitus: cause or effect?

Two patients with hypertriglyceridaemia which was diagnosed several years before the onset of diabetes are described. In the first case a 54-year-old man presented with hypertriglyceridaemia and normal glucose tolerance. After 4 years he developed severe hypertriglyceridaemia (22 mmol/l) which was first ascribed to poor compliance but soon afterwards diabetes was diagnosed and good blood glucose control minimized the hypertriglyceridaemia. The second patient, a female, aged 27 years, with the polycystic ovarian syndrome, presented with eruptive xanthoma after several years of mild hyperlipidaemia. There was severe hyperlipidaemia (triglyceride 140 mmol/l, cholesterol 42 mmol/l) which required urgent plasmapheresis. Diabetes was diagnosed and treated with insulin at this time but the patient was taking the oral contraceptive pill and also had a deficiency of apolipoprotein CII.

Adult↗

DNA polymorphisms of the insulin receptor gene in Japanese subjects with non-insulin-dependent diabetes mellitus.

Genotypes identified by two restriction fragment length polymorphisms (RFLPs) of the insulin receptor gene (IRG) with the restriction endonuclease Sst-1 were determined in a Japanese group comprising 51 patients with non-insulin-dependent diabetes mellitus (NIDDM) and 50 control subjects. Southern hybridization using a probe for the beta subunit of the human IRG identifies 4 alleles, termed S1(+) (5.3 kb), S1(-) (5.8 kb), S2(+) (7.0 and 2.4 kb) and S2(-) (9.4 kb). The frequencies of genotypes possessing the S1(-) allele in Japanese controls and Japanese NIDDM patients were 0.11 and 0.16, respectively. Unlike the previously reported association of the S1(-) allele with NIDDM found in Caucasians there was no significant difference in the frequency of the S1(-) allele between non-diabetic and NIDDM Japanese patients. There was a significant difference in the frequency of the S2(+) allele between Caucasian control subjects (0.14) and Japanese controls (0.0) and NIDDM patients (0.02).

Asian People↗

DNA polymorphic patterns and haplotype arrangements of the apo A-1, apo C-III, apo A-IV gene cluster in different ethnic groups.

The allelic frequency of five different restriction fragment length polymorphisms (RFLPs) in the A-1, C-III, A-IV gene region has been determined in Caucasians, Negroes, Indian Asians, and Japanese. The polymorphic sites are with Taq-1 at the 5' end of the A-1 gene, with Msp-1 in the third intron of the A-1 gene, with Pst-1 in the intergenic sequence between the A-1 and C-III genes, with Sst-1 in the 3' non-coding region of the C-III gene, and with Pvu-II in the third intron of the C-III gene. The alleles identified by three of the RFLPs showed large differences in frequency amongst the races, especially between Caucasians and non-Caucasians. Alleles of the Msp-1 polymorphism and Sst-1 polymorphism, which were rare in Caucasians (frequencies 0.03 and 0.01), were more common in Japanese (frequencies 0.37 and 0.35), Indian Asians (frequencies 0.37 and 0.26), and Negroes (frequencies 0.31 and 0.31). In contrast with a Pvu-II polymorphism one allele was rare in Japanese and in Indian Asians (frequency 0.01) but more common in Caucasians (frequency 0.11). Linkage disequilibrium was evident between some of the alleles and a total of seven haplotypes were identified among the different races.

Alleles↗