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D S Fredrickson

Publications and source records attributed to D S Fredrickson.

At least 109 records · Page 6Linked to original sources
PubMed1969

A comparison of heritable abnormal lipoprotein patterns as defined by two different techniques.

Eight plasma lipoprotein patterns currently employed in attempts to identify different forms of familial dyslipoproteinemia have been compared by two methods. The first (NIH method) is based on paper electrophoretic patterns produced by the four lipoprotein classes obtained by paper electrophoresis in albuminated buffer, coupled with the measurement of the total cholesterol of three of these lipoprotein classes and ascertainment of abnormal flotation of beta-migrating lipoproteins. The second (Donner method) is based on lipoprotein patterns obtained in the analytical ultracentrifuge, adapted for computer analysis and complemented by chemical determination of the concentration of chylomicrons (lipoproteins of S(f) degrees > 400). Pooled samples representing patients with five types of familial hyperlipoproteinemia and three different forms of inherited lipoprotein dificiency were separately analyzed. For six of the eight pools, both methods provided a distinctive lipoprotein pattern in terms of changes in one or more variables. For the remaining two pools, type IV hyperlipoproteinemia and the heterozygote for Tangier disease, both methods provided identical but not unique patterns. The results indicate that lipoprotein analyses obtained by either method may be used interconvertibly in further genetic and other clinical studies.

Abdomen↗
PubMed1969

Lipid abnormalities in foam cell reticulosis of mice, an analogue of human sphingomyelin lipidosis.

The lipid changes in the inheritable foam cell reticulosis of mice discovered by Lyons, Hulse, and Rowe have been reexamined. The major abnormality in thymuses from homozygous-abnormal animals has been identified as an increase in the concentration (per milligram of protein) of sphingomyelin and cholesterol. This increase is associated with normal sphingomyelin-cleaving activity. The lipid compositions of the liver and spleen in the homozygous-abnormal animal and of the thymus in the heterozygous-abnormal mouse are normal. The disorder appears to be chemically analogous to those forms of human sphingomyelin lipidosis (Niemann-Pick disease) that are not accompanied by a decrease in tissue sphingomyelinase.

Animals↗
PubMed1969

Evidence for separate monoglyceride hydrolase and triglyceride lipase in post-heparin human plasma.

Post-heparin plasma contains an enzyme or enzymes with both triglyceride lipase (TGL) and monoglyceride hydrolase (MGH) activities. A simple and reproducible radioactive assay for measurement of MGH activity was developed and used, with a previously reported assay for TGL, to study lipolysis in plasma. After the injection of heparin, enzymatic activity against both tri- and monoglycerides appeared and disappeared from plasma at approximately the same rates. However, in contrast to TGL activity, MGH activity was: (a) much greater, (b) considerably less heat-sensitive, (c) unaffected by three inhibitors (NaCl, protamine, and pyrophosphate), (d) not influenced by radical changes in fat and carbohydrate content of the diet, and (e) normal in familial Type I hyperlipoproteinemia. The dichotomy between MGH and TGL activities in patients with genetic deficiency of TGL constitutes strong evidence that these are two different enzymes. The findings further indicate that when post-heparin lipolytic activity is measured for the purpose of detecting TGL deficiency, it may be necessary to perform the assay with a substrate free from partial glycerides.

Diet↗