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Biomedical subjects

B F Main

Publications and source records attributed to B F Main.

3 recordsLinked to original sources
PubMed1993

Response of cholesterol synthesis to cholesterol feeding in men with different apolipoprotein E genotypes.

To investigate the influence of dietary cholesterol level and apolipoprotein (apo) E polymorphism on cholesterol synthesis, seven apo E2/- and six apo E4/- normolipidemic subjects consumed self-selected diets containing low cholesterol ([LC] 250 mg/d) and high cholesterol ([HC] 800 mg/d) levels for approximately 20 days. On day 20, subjects were given 0.7 g deuterium oxide (D2O)/kg body water followed by maintenance doses. Cholesterol synthesis was measured as the uptake rate of D into plasma free cholesterol over 24 hours. Serum total cholesterol levels were higher (P < .05) in the apo E4/- versus apo E2/- group over both dietary periods. No influence of dietary cholesterol content on serum levels was observed, nor was there an effect of apo E genotype or dietary cholesterol level on cholesterogenesis. However, a genotype-independent association was observed between both cholesterogenesis (P < .001) and the increase in cholesterogenesis (P = .05) with the change in serum total cholesterol level subsequent to high-cholesterol feeding. These findings suggest that (1) apo E genotype is not associated with cholesterol synthesis rate in subjects on self-selected diets, and (2) hyporesponders to a dietary cholesterol challenge display higher synthetic rates than hyperresponders. The observation of lower cholesterol synthesis in individuals with the largest increases in serum cholesterol level after a dietary cholesterol challenge suggests a passive rather than dominant role of cholesterol synthesis in regulating serum levels.

Adult↗
PubMed1991

Apolipoprotein E genotyping using the polymerase chain reaction and allele-specific oligonucleotide primers.

A method for apolipoprotein (apo) E genotyping was developed using the polymerase chain reaction (PCR) with allele-specific oligonucleotide primers (ASP). Synthetic oligonucleotides with base-pair mismatches at the 3' terminus were used as primers to amplify the apoE gene in subjects previously phenotyped using isoelectric focusing (IEF). Complementary primer-allele combinations were specifically amplified by PCR, together with a control pair of primers specific to the human prothrombin gene. Identification of genotype by PCR using ASP was consistent with the phenotypes that were determined by IEF for 14 healthy normolipidemic subjects. These results were achieved using DNA isolated from buccal epithelial cells obtained from a mouthwash or DNA extracted from leukocytes. Genotype identification required analysis of the PCR products on an ethidium-stained agarose gel, yielding results 3 h after DNA extraction. In comparison with other current methods, PCR using ASP is suggested as a rapid and simple noninvasive technique for determining population apoE allelic distribution.

Alleles↗