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Biomedical subjects

R D Ellefson

Publications and source records attributed to R D Ellefson.

At least 37 records · Page 2Linked to original sources
PubMed1982

Cholesterol excretion studies in familial hypercholesterolemic children and their normolipidemic siblings.

Twenty children ages 3 to 17 yr, eight with normal lipids and 12 with familial hypercholesterolemia were studied on a metabolic unit for 14 days to evaluate fecal bile acid and fecal neutral sterol excretion. The diet contained a moderately low cholesterol content, 180 to 200 mg/day. Stools were collected in three separate, 3-day pools. Fecal bile acids and fecal neutral sterols were measured using two stool markers and thin-layer, and gas-liquid chromatography techniques. Fecal neutral sterol and fecal bile acid excretion were the same for normal and familial hypercholesterolemic children on a mg/kg basis. Fecal neutral sterols in familial hypercholesterolemic children decreased with age, p less than 0.001; fecal bile acid excretion also appeared to decrease with age, but less significantly, p less than 0.07. Although the familial hypercholesterolemic children have significantly increased plasma and potentially elevated tissue or total body cholesterol, the excretion of fecal bile acids and fecal neutral sterols did not differ between familial hypercholesterolemic and normal children.

Adolescent↗
PubMed1982

Lipid synthesis in cutaneous xanthoma.

In vitro lipogenesis was studied on the xanthoma tissue from 6 patients with normal plasma lipids and 4 patients with hyperlipidemia. Xanthoma tissue was incubated at 37 degrees C for 6 hr in Krebs-Ringer phosphate buffer containing sodium [14C]acetate. The radioactivity of each lipid class was determined after extraction and separation of lipids. The incorporation of acetate into all major lipid groups was much greater in xanthoma tissue than in control normal-appearing skin. There was no difference in the incorporation pattern of 14C between xanthomas of patients with normal plasma lipids and those of hyperlipidemic patients. The data exemplify considerable in situ lipid synthesis of xanthoma tissue. Although the lipids in xanthomas of hyperlipidemic persons may be derived from plasma, the plasma origin of xanthoma lipids in normolipidemic persons remains to be confirmed, and the contribution of local lipogenesis cannot be ignored. The lipids in cutaneous xanthomas are most likely derived from a multiple input system.

Acetates↗
PubMed1981

Association of risk factor variables and coronary artery disease documented with angiography.

Stepwise linear discrimination was used to analyze risk factors in 431 consecutive patients who underwent coronary angiography to determine which variables were most closely associated with coronary artery disease. Twenty-one risk factors were considered: total plasma cholesterol and triglycerides; the cholesterol and triglyceride content of high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very low density lipoproteins (VLDL); and the percentage of total cholesterol and triglycerides in each fraction. Age, smoking history, family history, hypertension, diabetes mellitus and relative weight were also considered. Coronary artery disease was assessed using three standard grading scores. There were significant differences in risk factors between males and females. In males, LDL cholesterol and age were selected by multivariate analysis. In females, the ratio of HDL cholesterol to total cholesterol, as well as relative weight, family history, age and smoking were selected. The discriminating value of HDL cholesterol as the percentage of total cholesterol was significantly greater than that of HDL cholesterol itself. Despite highly significant associations between risk factors and the presence of coronary artery disease, the discrimination did not provide sufficient separation of the groups to give results that are useful diagnostically in individual patients.

Adult↗
PubMed1981

A prospective study of peripheral occlusive arterial disease in diabetes. III. Initial lipid and lipoprotein findings.

Lipid and lipoprotein findings are described in a group of 707 persons consisting of normal control subjects, patients with clinical peripheral occlusive arterial disease, patients with diabetes and no occlusive arterial disease, and diabetic patients with occlusive arterial disease. The mean serum triglycerides were elevated in all groups compared with the normal controls and varied, depending on the type and treatment of the diabetes and fasting plasma glucose concentration. Mean total serum cholesterol did not change among the groups. Unexpectedly, the mean level of low-density lipoprotein cholesterol was significantly lower in patients with diabetes who had no occlusive arterial disease than in normal subjects. The mean high-density lipoprotein cholesterol level was higher in normal-weight, insulin-treated diabetic patients than in obese diabetics regardless of their treatment. Disturbances in triglyceride metabolism and the related lipoproteins appear to characterize both diabetes and occlusive arterial disease, with the highest mean levels of serum triglycerides being found in subjects with both diabetes and occlusive arterial disease.

Aged↗
PubMed1981

Liquid-chromatographic analysis for urinary porphyrins.

Urinary porphyrins are separated, according to number of carboxyl groups, in a system consisting of a mu-Bondapak C18 stationary phase and a mobile phase of methanol and aqueous sodium phosphate (pH 3.5) in a linear gradient. The specimen is prepared simply by adjusting the pH of a 5-mL sample to 2.0 and removing solids by centrifugation. The eluted porphyrins are measured fluorometrically. Naturally occurring non-porphyrin fluorescent substances are eluted ahead of the porphyrins. Chromatography requires about 20 min, and a re-establishment of initial conditions requires an additional 15 min.

Adult↗
PubMed1980

Tissue lipids in hyperammonemic encephalopathies of childhood.

Cholesterol, triglyceride, free fatty acid, and phospholipid concentrations were measured in 33 brain, liver, and adipose tissue samples obtained from 17 children who died of an acute encephalopathy associated with liver dysfunction and hyperammonemia (hyperammonemic encephalopathy). Eleven patients had Reye's syndrome, three had acute "toxic" encephalopathy (without fatty liver), two had glycogen storage disease type 1, and one had congenital hyperammonemia type 2. Hepatic triglyceride concentrations were markedly increased in Reye's syndrome, but varied from normal to increased concentrations in other hyperammonemic encephalopathies. In contrast, the acute encephalopathy could not be differentiated on the basis of clinical, laboratory, or pathologic features and the brain lipid profiles were remarkably similar among all patients studied.

Adipose Tissue↗
PubMed1980

Removal of plasma lipoproteins from circulating blood with a heparin-agarose column.

A method is described for the removal of cholesterol fractions by means of intermittent extracorporeal plasma circulation through a column containing heparin-treated agarose in the presence of calcium. The system allows plasma perfusion in one column while simultaneously recharging another. In vitro testing demonstrated its efficiency, and in vivo testing of a normal dog proved its feasibility. In vitro testing revealed a mean removal of 22% of low-density and very low-density lipoproteins combined. Animal testing did not produce any abnormalities in clinically significant parameters.

Animals↗
PubMed1980

Day-to-day variability and analytic error in determinations of lipids in children.

In a pilot study, short-term (Monday, Wednesday, and Friday of the same week) variability of cholesterol and triglycerides in serum and in very low-density, low-density, and high-density lipoproteins were studied in 10 children aged 6 to 16. All of the subjects had normal levels of cholesterol and triglycerides. Analytic error was determined by blinded triplicate analyses of a fourth specimen from five of the same subjects. In the triglycerides, except for the smallest fraction (high-density), the differences from day to day in the same child were larger than the differences between children. The results indicate that single determinations of whole serum triglyceride carry limited significance since, within the week, the level may well change by a factor of two.

Adolescent↗
PubMed1980

Assay for erythrocyte uroporphyrinogen I synthase activity, with porphobilinogen as substrate.

We describe a convenient, economical procedure for measuring uroporphyrinogen I synthase (EC 4.3 1.8) activity in erythrocytes, the results of which can be used to diagnose acute intermittent porphyria, in either its latent or acute stage. By limiting the test reaction sequence to the conversion of porphobilinogen to porphyrins, we eliminated several disadvantages of alternative methods in which delta-aminolevulinate is used as substrate. The latter assay was inhibited by lead; our procedure was not. Our procedure also gave greater porphyrin synthesis with less substrate. Erythrocytes of healthy women presented a mean activity of 12.4 nmol of porphyrin formed per liter per second; erythrocytes of healthy men presented a mean activity of 11.0 nmol/L per second. The within-run coefficient of variation (CV) for our assay was 1.8%; the between-run CV was 3.1%.

Ammonia-Lyases↗
PubMed1980

The lipoprotein profile of chylous and nonchylous pleural effusions.

The lipoprotein electrophoregrams and the cholesterol and triglyceride levels of the pleural fluid were evaluated for patients with chylous pleural effusions, as defined by the presence of a distinctive band of chylomicrons on the lipoprotein electrophoregram, and in patients with nonchylous effusions of various causes. One hundred forty-one patients were studied during a 3-year period. The chylous effusions had strikingly higher triglyceride levels (median 249, range 49 to 2,270 mg/dl) than the nonchylous group (median 33, range 13 to 107 mg/dl); there were no significant differences in cholesterol or protein between the two groups. The gross description of the fluid was a poor indicator of its origin, being described as consistent with chyle in less than 50% of cases of chylous effusions. The triglyceride values distinguished chylous effusion from nonchylous effusion; values greater than 110 mg/dl are highly suggestive of a chylous effusion. Equivocal cases--triglyceride values between 50 and 110 mg/dl--required lipoprotein analysis. Pleural effusions of undetermined cause, regardless of gross appearance of the fluid, require that a screening triglyceride value be obtained to rule out a chylous effusion.

Cholesterol↗
PubMed1979

Sterol and bile acid metabolism during development. 3. Occurrence of neonatal hypercholesterolemia in guinea pig and its possible relation to bile acid pool.

The relationship of the changes in plasma cholesterol to bile acid pool was studied in the newborn guinea pig. Plasma cholesterol reached the maximum on the fifth day and gradually declined to adult levels. The cholesterol concentration in the high density lipoproteins (HDL) was higher in the newborn guinea pig than in the adult. Plasma triglycerides peaked on the third day and decreased markedly. The bile acid pool increased progressively after birth with a 13-fold increase at 5 days of age. While the hepatic triglycerides decreased sharply in the newborn guinea pig, hepatic cholesterol increased in the first 5 days and then decreased to adult levels. This study has described the occurrence of "neonatal hypercholesterolemia" in the guinea pig and its possible relationship to the low level of bile acid synthesis.

Aging↗
PubMed1979

Comparative effectiveness of dextrothyroxine and levothyroxine in correcting hypothyroidism and lowering blood lipid levels in hypothyroid patients.

Data reported here establish that treatment regimens of 4 mg dextrothyroxine and 0.15 mg levothyroxine in hypothyroid subjects produce similar degrees of lowering of serum TSH, cholesterol, triglycerides, and phospholipid levels and equal stimulation of metabolic rate. The Murphy-Pattee total T4 determination applied to blood samples drawn 24 h after the last dose of dextrothyroxine can be used to assess adequacy of treatment. Correction of hypothyroidism requires high serum levels of dextrothyroxine than of levothyroxine. Serum T3 levels increase in patients treated with dextrothyroxine. In the treatment of hypothyroidism, the cholesterol-lowering and metabolic rate-stimulating effects of dextrothyroxine do not appear to be dissociated. Further studies are needed to determine whether such an effect can be demonstrated in euthyroid hypercholesterolemic subjects with doses established herein as equivalent in terms of the stimulating effect on metabolic rate.

Basal Metabolism↗
PubMed1978

Combined deficiency of glucose-6-phosphatase and fructose-1, 6-diphosphatase. Studies of glucagon secretion and fuel utilization.

An adult woman with hypoglycemia, hyperlactatemia, hyperuricemia, hypertriglyceridemia, hyperketonemia and inability to make new glucose from galactose, fructose, glycerol and alanine was found to have no hepatic glucose-6-phosphatase and deficient fructose-1,6-diphosphatase. Nonautonomous hyperglucagonemia was demonstrated and shown to contribute to the hyperlactatemia and hyperketonemia. A paradoxic hyperlactatemic response to glucose and galactose was observed. Studies of substrate utilization showed prompt adaptation to changes in dietary supply of energy which probably accounted for her never having experienced symptoms of hypoglycemia.

Adult↗
PubMed1978

False-positive rubella hemagglutination-inhibition (HAI) titers in neonates and children with conjugated hyperbilirubinemia.

Two neonates, one with extrahepatic biliary atresia and one with cystic fibrosis, and a 9-year-old child with atresia of the common bile duct had conjugated hyperbilirubinemia and elevated rubella HAI titers when kaolin pretreatment of serum was used. A beta-lipoprotein fraction of the serum that is frequently found in association with biliary obstruction was shown to be the probable source of the rubella HAI inhibitor. This beta-lipoprotein was not removed by standard kaolin treatment of serum, but was removed almost completely by dextran sulfate--calcium chloride treatment. In the presence of conjugated hyperbilirubinemia, routine kaolin pretreatment of serum is an inadequate measure for the removal of interfering substances, as false-positive rubella HAI results are obtained consistently.

Antibodies, Viral↗
PubMed1978

Lipoprotein cholesterol in the serum of children, as determined independently by two different methods.

We separately evaluated split specimens of serum for lipoprotein cholesterol in 38 five- to 14-year-old children, by the heparin/Ca2+ precipitation method and the ultracentrifugation/dextran sulfate precipitation method. Statistical analysis of the results indicated an excellent agreement (especially in beta- and alpha-lipoprotein cholesterol values) between results by the two methods. The percentage of alpha-lipoprotein cholesterol (mean +/- SD: 38.6 +/- 5.0) in children further confirmed the earlier observations that cholesterol derived from alpha-lipoprotein in children constitutes a relatively greater part of the serum total cholesterol than is true of adults.

Adolescent↗
PubMed1978

Cholesterol and triglycerides in serum lipoproteins of young persons in Rochester, Minnesota.

Cholesterol and triglyceride levels in whole sera and in the major lipoprotein fractions are presented for 2,421 children and youths in Rochester, Minnesota, ranging in age from 6 to 18 years. This cross-sectional study revealed subtle changes associated with puberty and the occurrence of certain additional sex-specific changes related to age. Hyperlipoproteinemia was detected in 101 youngsters; those cases exemplified types IIa (61 cases), IIb (5 cases), III (5 cases), and IV (30 cases). One case of type V hyperlipoproteinemia was observed in a second and comparable population sample of 1,245 young persons.

Adolescent↗