Search PubMed⌕ Search

Biomedical subjects

G Wolfram

Publications and source records attributed to G Wolfram.

At least 109 records · Page 6Linked to original sources
PubMed1990

Effect of triiodothyronine on triglyceride synthesis in human fibroblasts in different types of hypertriglyceridemia.

Fibroblasts from 12 normotriglyceridemic subjects and 30 hypertriglyceridemic patients and family members were used to investigate triglyceride synthesis and the influence of triiodothyronine on it. The monolayers were incubated for 72 hours with and without the thyroid hormone, followed by incorporation studies of radiolabeled acetic acid or palmitic acid into the cellular triglyceride fraction. Triiodothyronine had no influence on triglyceride synthesis of normal cell lines and of cells derived from patients with secondary hypertriglyceridemia, whereas fibroblasts from endogenous type IV patients showed higher rates of triglyceride synthesis under identical conditions. Values for type IV were in the range of 134% to 466% of the hormone-free control incubations. In cultures derived from patients with familial combined hyperlipidemia, no stimulation by triiodothyronine was observed: values were in the range of 64% to 144% of the hormone-free controls. Three out of four lines with type V gave "normal" values and are supposed to represent secondary hypertriglyceridemia, whereas one line may express endogenous type IV. The evidence obtained in vitro with cultured cells indicates different metabolic defects in endogenous type IV and familial combined hyperlipidemia; it also shows the biochemically heterogenous nature of the disease "hypertriglyceridemia."

Acetates↗
PubMed1990

Association of DNA-haplotypes in the human LDL-receptor gene with normal serum cholesterol levels.

For the low density lipoprotein receptor (LDLR), many mutations have been characterized which identify this gene as one with an important role in lipid metabolism in patients with familial hypercholesterolemia (FH). Genetic heterogeneity at this locus raises the possibility that the LDLR may also contribute to variation in cholesterol levels in the normocholesterolemic population. We have determined genotypes at the LDLR locus using restriction fragment length polymorphisms (RFLPs) detected with the enzymes StuI, ApalI, PvuII and NcoI in 324 normocholesterolemic individuals from Germany. A significant association (p less than 0.01) was detected between the cutting site for the PvuII RFLP and lower cholesterol levels, and variation associated with this polymorphism explains 3% of the sample variance in cholesterol levels. In family studies we have determined four-RFLP haplotypes of 148 independent LDLR genes and have observed 9 haplotypes in the population. Three of these haplotypes containing the cutting site for PvuII are associated with a reduction in plasma LDL-cholesterol levels. Phylogenetic analysis indicates that these three haplotypes are related by evolutionary history, and this suggests that a single functionally important sequence change in the LDLR explains our observations. Our data confirm other reports and strongly suggest that the LDLR locus may be one of those genes involved in determining serum cholesterol levels in the normal population.

Adult↗
PubMed1990

Presence of growth hormone-releasing hormone-like immunoreactivity in human tumors: characterization of immunological and biological properties.

The distribution and physical and biological properties of GH-releasing hormone-like immunoreactivity (GHRH-IR) in human tissues and tumors was investigated using a specific GHRH RIA, gel chromatography, immunoaffinity chromatography, and bioassay with cultured rat anterior pituitary cells. Variable concentrations of GHRH-IR, ranging from 1.4-39.0 ng/g wet wt, were found in normal liver, lung, placenta, and pancreas. In the latter tissue, however, a different chromatographic profile and a marked decrease in GHRH-IR after immunoaffinity occurred, suggesting that GHRH-IR in pancreatic extracts is not native GHRH. In all tumors examined (n = 35) GHRH-IR could be detected, and four tumors (three carcinoids and one jejunal carcinoma) contained a very high amount of GHRH-IR (greater than 1000 ng/g wet wt). Affinity chromatography of tumor extracts led to a significant loss (greater than 50%) of GHRH-IR in nine tumors. The four tumors containing large amounts of GHRH-IR were obtained from two patients with active acromegaly and two patients who had no clinical evidence of acromegaly. Using antibodies with different specificities for GHRH-(1-44) and GHRH shortened at the C-terminus, varying concentrations of GHRH-(1-44) in these tumors were found, ranging from 10-87% of the total GHRH-IR. The biological activity of GHRH in the four tumor extracts was similar to that of synthetic GHRH alone or GHRH added to control tissue subjected to extraction. These results demonstrate the presence of GHRH-IR in the majority of normal tissues and tumors, which, though they may produce large amounts of biologically active GHRH, do not always lead to acromegaly.

Adolescent↗
PubMed1990

[Position of sugar in nutrition].

Carbohydrates are an indispensible component in the nutrition of humans, because certain tissues depend on glucose. Together with the carbohydrate-containing foodstuffs also essential nutrient and dietary fiber should be added, since, besides a general overconsumption in the FRG, risk groups such as pregnant women and elderly people can suffer from a biochemical measurable deficiency of certain vitamins and trace elements. Only in its processed form in several foodstuffs sugar promotes the supply of essential nutrients. These foodstuffs must be judged by their nutrient density, in which the level of dietary fiber is mostly too low.

Age Factors↗
PubMed1990

[Is sugar involved in the development of cardiovascular diseases?].

The hypothesis that sugar promotes the development of coronary diseases could not be confirmed by several epidemiological studies. But sugar can, through its high energy density in sugar-containing foodstuffs, indirectly lead to obesity and diabetes, and to early arteriosclerosis. A sugar- or carbohydrate-rich diet leads, in healthy persons, to a short-term hypertriglyceridemia which disappears after a short time following the adaptation of the metabolism. Certain people with a hereditary disposition toward metabolic disturbances also react, after a longer exposure to higher sugar consumption, with a rise of the triglycerides in plasma.

Coronary Artery Disease↗
PubMed1990

[Socio-demographic characteristics of participants in natural family planning introductory courses. Final report of a pilot study].

Participants in courses of natural family planning methods were questioned regarding sociodemographic characteristics, previously and last used family planning methods and their motivation for course attendance. The method used most often previously was the 'pill' (47.6%), natural family planning came next with 35.8%. Among the methods used last, natural family planning dominated with 38%, followed by the pill (27.1%). The main motives given by both men and women for attending the course were 'quest for an alternative method' (36.1%), 'considerations about health' (31.4%).

Adult↗
PubMed1989

[Medium-chain triglycerides--useful energy carriers in parenteral nutrition].

The use of medium-chain triglycerides (MCT) in lipid malabsorption and lipoproteinlipase deficiency is well established. It is known from experiments in animals and humans that after parenteral administration MCT are rapidly hydrolyzed by lipoprotein lipase in plasma. The liberated medium-chain fatty acids are taken up independently of carnitine by mitochondria and oxidized to CO2 in extrahepatic tissues more rapidly than long-chain fatty acids. Medium-chain fatty acids are ketogenic, and consequently both medium-chain fatty acids and ketones are carnitine-independent energy carriers for different tissues. By simultaneously infusing glucose the risk of ketoacidosis can be minimizes. MCT in parenteral nutrition is a substrate which provides high-density energy without problems regarding osmolality or renal losses and with less interference to the reticulohistiocytes of the immune system. On the basis of these metabolic and functional properties MCT represent a valuable additional energy source in total parenteral nutrition.

Energy Metabolism↗
PubMed1989

Four DNA polymorphisms in the LDL-receptor gene and their use in diagnosis of familial hypercholesterolemia.

To examine the potential usefulness of restriction fragment length polymorphisms (RFLPs) for diagnosis of familial hypercholesterolemia (FH), we determined the genotype of FH patients and their relatives for the Apa1I, NcoI, PvuII and StuI RFLP of the LDL-receptor gene in a sample of German patients attending the Lipid Clinic in Munich. There was no significant difference in the relative allele frequency between the group of FH patients and controls for any of the four polymorphisms. Using linkage analysis, we could determine the four-RFLP haplotypes of 39 defective and 90 normal LDL-receptor genes in 38 FH families. In our sample, defective LDL-receptor genes occur on 6 different chromosomes determined by the four RFLPs. This suggests that at least 6 different genetic defects may cause FH in this sample. RFLPs of the LDL-receptor gene cannot be used to detect FH in individuals; however, appropriate diagnosis can be carried out in more than 90% of families using linkage analysis and these RFLPs.

Gene Frequency↗
PubMed1989

[Distribution and elimination of medium- and long-chain fatty acids of a fat emulsion in lipoproteins of severely injured patients following bolus injection].

A fat emulsion containing 20% fat as medium chain triglycerides (MCT) and long chain triglycerides (LCT) (1:1) was injected as a bolus in an amount of 0.2g fat per kg body weight to six patients, three to five days after a serious injury. Triglyceride concentrations increased within two min in lipoprotein fractions d less than 0.95 g/ml (Chylomicrons), d less than 1.006 g/ml (VLDL), d less than 1.063 g/ml (LDL) and d less than 1.21 g/ml (HDL). Sixty minutes after injection triglyceride concentrations had again reached preexperimental values in all lipoprotein fractions. Cholesterol values did not change. According to the composition of the fat emulsion, linoleic acid content increased in triglycerides of all lipoprotein fractions, whereas octanoic and decanoic acid did so only in triglyceride-rich lipoproteins (d less than 1.006). Half-life values of elimination of octanoic acid (3.3 min) and decanoic acid (3.9 min) in triglycerides of lipoprotein fraction d less than 1.006 were nearly half as short as that of long chain fatty acids (linoleic acid, 6.4 min; oleic acid, 6.5 min; palmitic acid, 7.5 min). Thus in contrast to LCT, MCT are only found in triglyceride-rich lipoproteins (d less than 1.006) and are also eliminated more rapidly.

Fat Emulsions, Intravenous↗
PubMed1989

Effects of acarbose on serum lipoproteins in healthy individuals during prolonged administration of a fiber-free formula diet.

The effects of the disaccharidase inhibitor acarbose on serum lipoprotein lipid concentrations were investigated in healthy subjects during prolonged feeding of a fiber-free formula diet. Acarbose was shown to decrease cholesterol and fasting triglyceride concentrations, whereas the postprandial increment of triglycerides was not diminished. The response of fasting triglycerides to acarbose treatment appeared to be related to dietary fat intake, but not to the drug-induced reduction of postprandial glucose and insulin concentrations. Both the triglyceride and the cholesterol lowering efficacy were less pronounced with a higher amount of saturated fat than with a lower intake of fat mainly composed of polyunsaturated fatty acids. The decrease in total cholesterol was shown to be a consequence of a significant reduction in low density lipoprotein (LDL) cholesterol. Since high density lipoprotein (HDL) cholesterol concentrations remained unaltered, the ratio of HDL/LDL cholesterol changed in a beneficial way.

Acarbose↗
PubMed1989

[Variability and circadian rhythms of maintenance energy expenditure in adult humans].

Using indirect calorimetry the energy expenditure of healthy subjects was investigated as complete 24-hour balance measurements. The respective data were evaluated with regard to level, variation and normalizing of heat production (HP) and maintenance requirement. Diets were composed of customary ingredients and the intake of energy maintained constant slightly below maintenance requirement during the 14-day experimental period. Faeces and urine were collected for the final 7 days. Exchange of oxygen and carbon dioxide was measured during the last 48 h while the subjects stayed in an open-circuit respiration chamber, furnished like a small living-room. The daily energy balance averaged -0.38 MJ (+/- 0.73). For data evaluation the HP of each subject was corrected to zero energy balance, assuming a calorigenic effect of 10% for mixed diets. The resulting energy requirement of metabolizable energy for maintenance at energy equilibrium amounted to 136 (+/- 17) MJ/kg body weight and 383 (+/- 45) kJ/(kg body weight)0.75, respectively. Scaling the body weight to the 3/4 power diminished slightly the coefficient of variation. The observed total variance of the HP was mainly contributed by the subjects per se (94%), whereas only a small amount was related to day-to-day variability (6%; measurement noise and intraindividual variability). In terms of coefficient of variation the respective values were 11.5 and 2.8%. Comparable assessments with sows showed nearly the same results on animal variance and day-to-day variability. The daily time pattern of HP showed two maxima and two minima. In the morning and evening the HP exceeded the average 24 h value by 19 and 14%, respectively. During afternoon a value of 11% was observed. However, after midnight HP fell 31% under the daily mean. The relation between daily minimum and maximum was 1.7:1. During night the subject standard deviation was 8.6% compared to about 12% in the daytime. It is concluded that the total experimental error observed generally in whole-body indirect calorimetry studies is mostly attributable to subject variability. Furthermore, the variation of energy expenditure may account for deviations up to 10% or more between individual requirement and recommendations for predicting energy requirements.

Adult↗
PubMed1989

[Nutrition survey of adults using a 7-day protocol--a pilot study in the Augsburg MONICA project].

During the MONICA-project nutrition as one factor for the development of coronary heart disease is examinated. The individual intake of total energy, of fat-including saturated and unsaturated fatty acids-and of alcohol should be determined. This pilot study was done before the first cohort study within the MONICA-project Augsburg. The nutritional data were collected from february to march 1984 with the 7-day-dairy-record-method. 65 of totally 112 received records were suitable for evaluation by the computer program KALI (version 2.1.4). The 35 male persons had an average energy intake of 2.677 kcal/day. The average daily energy intake of the 30 female persons decreased with age. The main energy source for all persons is fat. Five women and eight men have an average intake of more than 500 mg cholesterol/day. Estimations of the intake of fatty acids were not possible, because of the specification of the computer program. Carbohydrates supply about 36% in men and 40% in women of the total energy, protein about 13% and 16% respectively. Men are drinking about 44 g alcohol/day. This is distinctly more than women do. Womens daily intake of vitamin B1, vitamin B6 and iron was lower than the recommendations of the German Nutrition Society. It's the same with vitamin B6 for men.

Adult↗
PubMed1988

Reduction of Lp(a) by different methods of plasma exchange.

Lipoprotein(a) has been shown to be an independent risk factor for atherosclerosis. The effect of different forms of plasmapheresis therapy on the removal of Lp(a) is examined. Plasmapheresis is successfully administered in a small number of hypercholesteremic patients who fail to respond to conventional therapy. Comparison of four different methods of plasma exchange (albumin substitution, anti-apoB antibody column, LDL precipitation, filtration) reveals significant differences in effectiveness in the ability to lower plasma Lp(a): plasma exchange with albumin und LDL precipitation seem to be the most effective, plasma filtration the least.

Adolescent↗
PubMed1988

Unusual but reversible hepatic lesions following long-term treatment with pyridylcarbinol for familial hypercholesterolemia.

We report two cases of unusual hepatic lesions following years of monotherapy with pyridylcarbinol (timespan) in a daily dose of 1.35 to 1.5 g for familial hypercholesterolemia. Mild elevations of liver enzymes correlated to a large tumor-like mass in the gallbladder region in one case and nodular changes in the whole liver (diagnosed by ultrasound) similar to metastatic lesions. After discontinuation of pyridylcarbinol the changes in the liver regressed markedly in both cases.

Adult↗