Howard A. Eder

Bio: Howard A. Eder is an academic researcher from Rockefeller University. The author has contributed to research in topics: Cholesterol & Lipoprotein. The author has an hindex of 18, co-authored 28 publications receiving 10636 citations.

The distribution and chemical composition of ultracentrifugally separated lipoproteins in human serum

Abstract: In the past few years several methods have been developed for the analysis of serum lipoproteins Lindgren, Elliott, and Gofman (1) have utilized the relatively low density of the lipoproteins to separate them from the other serum proteins by ultracentrifugal flotation Quantitation was subsequently performed by refractometric methods in the analytical ultracentrifuge Separations of lipoproteins have also been made by Cohn fractionation in cold ethanol, and the quantities of lipoprotein have been estimated from the lipid content of the fractions (2, 3) Widely used at the present time is the method of zone electrophoresis with quantitation either by staining (4) or by chemical analysis of eluates from the support

Plasma lipoprotein metabolism in perfused rat livers. ii. transfer of free and esterified cholesterol into the plasma

Abstract: When cholesterol was a dietary component (2% of the diet), it was dissolved in olive oil and fed for 5 to 7 days, except in the experiments described in Tables VI, VII, and VIII; in those, cholesterol was fed for 12 to 14 days in order to produce livers of very high lipid content. Liver perfusion. The technique of perfusion of Miller and associates (6, 7) was used. Mevalonic acid-2-C'4 was used as sterol precursor. In some experiments, 3.3 to 5.5 ,sc (0.7 to 1.2 mg) was added directly to the perfusing blood; one-third of the total was added at the start of the experiment, and the rest, by continuous injection during the perfusion (2 to 4 hours). In other experiments, designed to study the transfer of labeled cholesterol from liver to plasma, 11 ,uc of mevalonic acid-2-C"4 was given in two ip injections to the rats used as liver donors, at 16 hours and 3 hours before removal of their livers.

Serum lipoproteins and apolipoproteins in rats with streptozotocin-induced diabetes.

Abstract: The lipoproteins of rats fed a high sucrose diet and made diabetic by administration of 45 mg/kg of streptozotocin were studied. All lipoprotein classes were found to be present in increased concentrations. The apolipoprotein composition of the various lipoprotein fractions was studied by polyacrylamide-gel electrophoresis in the presence of 8 M urea, isoelectric focusing in the presence of 8 M urea, and sodium dodecyl sulfate gel electrophoresis in polyacrylamide gels. In the very low density lipoproteins (VLDL) of diabetic rats, there was a marked alteration in the relative amounts of C proteins by polyacrylamide-gel electrophoresis, and this was found by isoelectric focusing to be primarily a relative increase in C-III-3 apoprotein and a decrease in C-III-O. In addition, in the diabetic rats, the VLDL contained a protein of mol wt 46,000, the A-IV protein, which normally is only present in the high density lipoproteins. In the high density lipoproteins, (HDL) the same alterations in pattern of the C proteins seen in the VLDL were present. Furthermore, the arginine-rich and A-IV protein normally present in HDL could not be detected in the HDL, although the other apolipoproteins are present. Apolipoprotein concentrations were determined by quantitative immunoelectrophoresis. It was found that in the diabetic rats there was an increase in the total amount of apo-B in the plasma, with the increment divided proportionately between the VLDL and the low density lipoprotein (LDL). The total apo-C concentration of plasma increased minimally. The A-IV concentration of plasma increased by 27%; it decreased markedly in the HDL, but appeared in increased amounts in both VLDL and in the d greater than 1.21 fraction. The arginine-rich protein decreased by 63% in the plasma and decreased significantly in the HDL, but increased in VLDL, LDL, and in the d greater than 1.21 fraction. These alterations in apolipoprotein patterns in diabetic animals suggest that the apolipoproteins may play an important role in determining the concentration of various lipoprotein fractions, or may be the result of altered metabolism of the lipoproteins. These lipoproteins with altered apolipoprotein composition may have important biologic differences from normal lipoporteins. Nevertheless, the HDL, despite the fact that it is deficient in some of its major constituents, was unchanged in its cholesterol content.

Dietary treatment of hypertension. clinical and metabolic studies of patients on the rice-fruit diet

Abstract: This report is based on a study of six patients who were treated for hypertension by means of the rice-fruit diet of Kempner (1). During the six months of study with the patients in continuous residence on a metabolic ward observations were made to follow the evolution of both clinical and metabolic changes. The purpose of this study was the analysis of certain aspects of the necessity and the sufficiency of the rice-fruit program as applied to selected patients in a controlled environment. To this end evidence will be presented to demonstrate that objective clinical improvement actually occurred in these patients while they were under detailed metabolic observation. Whether the high incidence of clinical improvement observed was due to the selection of relatively young and uncomplicated hypertensive subjects or due to the detailed supervision of dietary intake or even whether the sheltered environment of a metabolic ward may have contributed to the favorable effects was not investigated. These considerations, although pertinent to the general problem of dietary treatment (2), are not directly relevant to the present issue of association between clinical and metabolic change.

The distribution and chemical composition of ultracentrifugally separated lipoproteins in human serum

Abstract: In the past few years several methods have been developed for the analysis of serum lipoproteins Lindgren, Elliott, and Gofman (1) have utilized the relatively low density of the lipoproteins to separate them from the other serum proteins by ultracentrifugal flotation Quantitation was subsequently performed by refractometric methods in the analytical ultracentrifuge Separations of lipoproteins have also been made by Cohn fractionation in cold ethanol, and the quantities of lipoprotein have been estimated from the lipid content of the fractions (2, 3) Widely used at the present time is the method of zone electrophoresis with quantitation either by staining (4) or by chemical analysis of eluates from the support

Nile red: a selective fluorescent stain for intracellular lipid droplets.

Abstract: We report that the dye nile red, 9-diethylamino-5H-benzo[alpha]phenoxazine-5-one, is an excellent vital stain for the detection of intracellular lipid droplets by fluorescence microscopy and flow cytofluorometry. The specificity of the dye for lipid droplets was assessed on cultured aortic smooth muscle cells and on cultured peritoneal macrophages that were incubated with acetylated low density lipoprotein to induce cytoplasmic lipid overloading. Better selectivity for cytoplasmic lipid droplets was obtained when the cells were viewed for yellow-gold fluorescence (excitation, 450-500 nm; emission, greater than 528 nm) rather than red fluorescence (excitation, 515-560 nm; emission, greater than 590 nm). Nile red-stained, lipid droplet-filled macrophages exhibited greater fluorescence intensity than did nile red-stained control macrophages, and the two cell populations could be differentiated and analyzed by flow cytofluorometry. Such analyses could be performed with either yellow-gold or red fluorescence, but when few lipid droplets per cell were present, the yellow-gold fluorescence was more discriminating. Nile red exhibits properties of a near-ideal lysochrome. It is strongly fluorescent, but only in the presence of a hydrophobic environment. The dye is very soluble in the lipids it is intended to show, and it does not interact with any tissue constituent except by solution. Nile red can be applied to cells in an aqueous medium, and it does not dissolve the lipids it is supposed to reveal.

Spontaneous Hypercholesterolemia and Arterial Lesions in Mice Lacking Apolipoprotein E

Abstract: Apolipoprotein E (apoE) is a ligand for receptors that clear remnants of chylomicrons and very low density lipoproteins Lack of apoE is, therefore, expected to cause accumulation in plasma of cholesterol-rich remnants whose prolonged circulation should be atherogenic ApoE-deficient mice generated by gene targeting were used to test this hypothesis and to make a mouse model for spontaneous atherosclerosis The mutant mice had five times normal plasma cholesterol, and developed foam cell-rich depositions in their proximal aortas by age 3 months These spontaneous lesions progressed and caused severe occlusion of the coronary artery ostium by 8 months The severe yet viable phenotype of the mutants should make them valuable for investigating genetic and environmental factors that modify the atherogenic process

Waist circumference and abdominal sagittal diameter: Best simple anthropometric indexes of abdominal visceral adipose tissue accumulation and related cardiovascular risk in men and women

Abstract: The amount of abdominal visceral adipose tissue measured by computed tomography is a critical correlate of the potentially "atherogenic" metabolic disturbances associated with abdominal obesity. In this study conducted in samples of 81 men and 70 women, data are presented on the anthropometric correlates of abdominal visceral adipose tissue accumulation and related cardiovascular disease risk factors (triglyceride and high-density lipoprotein cholesterol levels, fasting and postglucose insulin and glucose levels). Results indicate that the waist circumference and the abdominal sagittal diameter are better correlates of abdominal visceral adipose tissue accumulation than the commonly used waist-to-hip ratio (WHR). In women, the waist circumference and the abdominal sagittal diameter also appeared more closely related to the metabolic variables than the WHR. When the samples were divided into quintiles of waist circumference, WHR or abdominal sagittal diameter, it was noted that increasing values of waist circumference and abdominal sagittal diameter were more consistently associated with increases in fasting and postglucose insulin levels than increasing values of WHR, especially in women. These findings suggest that the waist circumference or the abdominal sagittal diameter, rather than the WHR, should be used as indexes of abdominal visceral adipose tissue deposition and in the assessment of cardiovascular risk. It is suggested from these data that waist circumference values above approximately 100 cm, or abdominal sagittal diameter values > 25 cm are most likely to be associated with potentially "atherogenic" metabolic disturbances.