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C C Walden

Publications and source records attributed to C C Walden.

12 recordsLinked to original sources

Apolipoprotein E in hyperlipidemia.

PURPOSE: To review DNA analysis of apolipoprotein E used to assess patients with hyperlipidemia. DATA SOURCES AND STUDY SELECTION: 44 basic science studies of molecular analysis; 42 basic science studies of the biochemical, cellular biological, and molecular biological features of apolipoprotein E; and 29 clinical investigational studies, meta-analyses, and case series of patients with mutations in apolipoprotein E. DATA EXTRACTION: Methods of DNA analysis were reviewed, using specific examples in human disease, and the role of apolipoprotein E in normal and disordered lipoprotein metabolism was reviewed. Genetic analysis of apolipoprotein E in populations and particularly in persons with type III hyperlipoproteinemia is reviewed. DATA SYNTHESIS: In the general population, common DNA variants of apolipoprotein E are consistently associated with modest differences in plasma lipids and lipoproteins. Homozygosity for the E2 isoform of apolipoprotein E predisposes some patients to the development of type III hyperlipoproteinemia, a condition that involves an additional genetic or environmental factor for full clinical expression. Rare mutations of apolipoprotein E also cause hyperlipidemia. CONCLUSIONS: DNA variation of apolipoprotein E is one of several genetic and environmental factors that interact in a complex manner to affect plasma lipoproteins. DNA analysis of apolipoprotein E can be used in persons with hyperlipidemia to identify those with type III hyperlipoproteinemia and in relatives of affected persons to identify those who are predisposed.

Apolipoproteins E↗

Detection of a new apolipoprotein-E mutation in type III hyperlipidemia using deoxyribonucleic acid restriction isotyping.

While determining the apolipoprotein-E (apo-E) genotype of 22 patients with type III hyperlipidemia (HLP III) by restriction isotyping, we identified a new mutant form of apo-E by its unusual DNA restriction fragment length polymorphism pattern. DNA sequence analysis of a polymerase chain reaction-amplified portion of the proband's apo-E gene revealed the substitution of cysteine (TGC) for arginine (CGC) at position 136 in the mutant allele (designated R136C). Lipoproteins containing this mutant protein bound defectively to macrophages in vitro, confirming the contribution of R136C to the expression of HLP III in the proband. The proband's two siblings carried the mutant allele and were also heterozygous for E2. Each also had dysbetalipoproteinemia (indicated by the presence of beta-very low density lipoprotein), but neither was hyperlipidemic, attesting to the importance of other factors for the full expression of HLP III. The mutant allele appears to contribute to the inheritance of HLP III in a recessive fashion. Restriction isotyping facilitates the diagnosis of subjects with HLP III, aids in the identification of affected individuals through family screening, and can contribute to the discovery of new mutations that help explain the pathogenesis of HLP III.

Adult↗

Biosynthesis of pyocyanine by a paraffin hydrocarbon-oxidizing strain of Pseudomonas aeruginosa.

A paraffin-oxidizing bacterium, designated as Pseudomonas aeruginosa ATS-14, was isolated from soil samples obtained from the Athabasca "tar sands." This strain utilized kerosene as the only carbon source of energy and produced a high concentration of pyocyanine in the culture medium. Aromatic carbons were not attacked, but C(10) to C(17)n-alkanes were readily oxidized by the pseudomonad and formed pyocyanine. The highest yield of the pigment was obtained from hexadecane and heptadecane.

Alkanes↗