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Biomedical subjects

C Nelson

Publications and source records attributed to C Nelson.

At least 181 records · Page 10Linked to original sources
PubMed1982

Effects of dietary cholesterol and fatty acids on plasma lipoproteins.

The effects of dietary cholesterol and fatty acids on low density and high density lipoproteins (LDL and HDL) were studied in 20 young men. After 2-3 wk of evaluations on ad lib. diets, basal diets, which consisted of 15% protein, 45% carbohydrates, 40% fat, and 300 mg/day of cholesterol, were given for 4-5 wk (Basal). The ratio of dietary polyunsaturated to saturated fatty acids (P/S) for different groups of subjects were 0.25, 0.4, 0.8, or 2.5. 750 and 1,500 mg/d of cholesterol were added to the basal diets as 3 and 6 eggs, respectively. Total cholesterol and LDL cholesterol were lower in all subjects on the basal diets than on the ad lib. diets. Addition of 750 mg cholesterol to the diet with P/S = 0.25-0.4 raised LDL cholesterol by 16 +/- 14 mg/dl to 115% of basal diet values (n = 11, P less than 0.01); 1,500 mg increased LDL cholesterol by 25 +/- 19 mg/dl to 125% (n = 9, P less than 0.01). On the diet with P/S = 0.8, 750 mg produced insignificant increases in LDL cholesterol, but 1,500 mg produced increases of 17 +/- 22 mg/dl to 115% of basal (n = 6, P less than 0.02). On the P/S = 2.5 diet, neither 750 nor 1,500 mg produced significant changes. Thus, both the cholesterol contents and P/S ratios of diets were important in determining LDL levels. The lipid and apoprotein compositions, flotation rates, molecular weights, and binding by cellular receptors of LDL were virtually unchanged by the addition of cholesterol to the diets high in saturated fat. These diets, therefore, caused an increase in the number of LDL particles of virtually unchanged physical and biological properties. On the diet with low P/S ratio, HDL2 rose, whereas this effect was absent on diets with high P/S ratios. The response of LDL to dietary manipulations is consonant with epidemiologic data relating diets high in cholesterol and saturated fat to atherogenesis. The response of HDL2, however, is opposite to that of its putative role as a negative risk factor. Further work is needed to clarify this interesting paradox.

Adult↗
PubMed1980

Improvements in hemoglobin AI determination by rapid cation-exchange chromatography.

The accuracy of many convenient methods for determining the proportion of hemoglobin AI to total hemoglobin by ion-exchange chromatography is in question because those methods have not been evaluated against a reference method. In addition, several if not all of these tests are influenced by laboratory temperature. We modified the chromatographic conditions usually used, to arrive at a method that gives results that agree well with those by the Trivelli method (N. Engl. J. Med. 284, 353, 1971) and is less influenced by ambient temperature than are results obtained with the commercially available Helena and Isolab kits. We accomplished this by lowering the pH of the fast-hemoglobin eluting buffer, with a corresponding adjustment in the ionic strength. We also use a larger elution volume, which assures more nearly complete elution of the hemoglobin A1 fraction. The final method (y) agreed being y = 0.98x + 0.63 r2 = 0.887. Average results from the Helena and Isolab methods were lower than with the reference method by 1.58 and 3.03% hemoglobin A1, respectively.

Chromatography, Ion Exchange↗
PubMed1977

Provocative testing for coronary arterial spasm: rationale, risk and clinical illustrations.

Two cases of Prinzmetal's variant angina are presented in which coronary spasm was documented by electrocardiographic evidence obtained in the coronary care unit during provocative testing with ergonovine maleate after the arteriographic demonstration of anatomically normal coronary arteries. The rationale and risks of provocative testing for spasm in patients with chest pain and anatomically normal coronary arteries are reviewed. The advantages of performing provocative testing in the coronary care unit after arteriography rather than in the catheterization laboratory during coronary arteriography are discussed.

Adult↗
PubMed1977

Labeling and recording orders for intravenous solutions: the concept of total amounts of ingredients.

A system of nomenclature for labeling and recording information on orders for parenteral solutions was developed using the concept of total amounts of ingredients. Compared with the traditional nomenclature, the new system is more useful for monitoring, is less ambiguous, saves time in recording and labeling, is easier to check, and is readily automated. An error study showed a significant decrease in "wrong solution" errors with the new system. No important problems occurred during the changeover from the traditional to the new nomenclature.

Computers↗
PubMed1976

Linking health needs and facility location: the HCPM's challenge.

How many people in your area have health needs? What are their needs? Are the right services reaching them? How should facilities be located so that their needs can be met? The author discusses how these questions often are addressed in a way that produces accurate answers + and offers some organized ways to find them.

Demography↗