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Biomedical subjects

G Wolfram

Publications and source records attributed to G Wolfram.

At least 163 records · Page 9Linked to original sources
PubMed1984

Effect of different linoleic acid intakes on prostaglandin biosynthesis and kidney function in man.

Prostaglandin (PG) biosynthesis and kidney function was investigated in 24 adults (23 to 32 yr) during isocaloric formula diet periods, for 2 wk each, providing a linoleic acid supply of 0, 3, 3.5, 4, 6, 8, 13, 17, 18, or 20% of total energy intake. Total protein intake (15 energy %) was constant, as well as 5 g NaCl, 3 g KCl, and 0.6 g cholesterol per 2200 kcal formula diet. The amount of PG metabolites, PG-E, sodium, and creatinine in 24-h urine increased with augmented linoleic acid intake. Comparing a linoleic acid intake of 0 and 20 energy %, an increase of sodium (8%) and creatinine (16%) in 24-h urine was found on the 5th day of high linoleic acid supply. Coincidently a stimulated PG biosynthesis could be measured. Potassium, water, and PG-F excretion showed no relation to linoleic acid intake. It is concluded that linoleic acid in the diet stimulates PG-E biosynthesis in man, leading to effects in systems which control renal function, and may have clinical relevance for the sodium and potassium balance in man.

Adult↗
PubMed1983

[Essential fatty acids in the plasma of severely injured patients under parenteral feeding].

After a heavy injury there are characteristic changes of plasma lipids and lipoproteins. In 7 patients up to 40 days after major injury the fatty acids of cholesteryl esters, phospholipids and triglycerides in plasma under the influence of injury, parenteral nutrition with carbohydrates or fat, and protein-sparing therapy were determined by gas liquid chromatography. These patients' increased requirement for linoleic acid is further increased by up to more than 50 g per day by carbohydrate-rich parenteral nutrition, inhibiting lypolysis of linoleic acid from adipose tissue. Protein-sparing therapy without carbohydrates is not sufficient to cover the patients' increased requirement for linoleic acid. Thus, the early administration of fat emulsions in parenteral nutrition is recommended.

8,11,14-Eicosatrienoic Acid↗
PubMed1983

[Extracardiac atherosclerosis in patients with familial hypercholesterolemia].

Among 64 patients with familial hypercholesterolemia (FHC) confirmed by tissue culture of skin fibroblasts (3 homozygotes, 9 heterozygotes) 12 (3 homozygotes, 9 heterozygotes) had signs of atherosclerosis of the carotid arteries and of the peripheral arteries (extracardiac vasculature). 8 heterozygotes as well as the three homozygotes had coronary atherosclerosis. Three of the 12 patients with carotid artery disease suffered from clinical symptoms of cerebrovascular insufficiency. Only five patients with heterozygous FHC had symptomatic peripheral artery disease though 10 including the three homozygotes had signs of atherosclerosis of the abdominal aorta and its peripheral branches. It is concluded that patients with FHC develop generalized atherosclerosis but not always symptoms of peripheral artery disease. Risk factors other than hypercholesterolemia do not seem to contribute essentially to the development of atherosclerosis. It seems important to evaluate patients with FHC regularly for atherosclerosis of the carotid arteries which might be recognized earlier than coronary atherosclerosis.

Adolescent↗
PubMed1983

Regulation of lipogenic enzymes in human diploid fibroblasts by hormones.

The hormonal regulation of two regulatory enzymes of fatty acid synthesis acetyl-CoA carboxylase (EC 6.4.1.2) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49), has been investigated in human diploid fibroblasts. There was a 35% increase in acetyl-CoA carboxylase activity, 72 h following addition of 10 microU/ml insulin to the culture medium. Addition of 1 microgram/ml of 3,3'5-triiodothyronine for 72 h resulted in an increase in acetyl-CoA carboxylase activity to 166% of the controls. The simultaneous addition of 1 microgram/ml triiodothyronine and 10 mU/ml insulin caused the enzyme activity to rise to 240% of the controls. A dose-dependent reduction in acetyl-CoA carboxylase activity was brought about by 1 X 10(-4) to 1 X 10(-3) M dibutyryl cyclic AMP. The earliest effect of dibutyryl cyclic AMP was observed within 24 h. Glucose-6-phosphate dehydrogenase followed qualitatively the same pattern of response, whereas the constitutive enzyme, lactate dehydrogenase (EC 1.1.1.27), did not show significant changes in these experiments. The data demonstrate common features of hormonal regulation of lipogenesis in human fibroblasts with liver and adipose tissue and substantiate the growing evidence that thyroid hormones are of major importance for the regulation of this process.

Acetyl-CoA Carboxylase↗
PubMed1983

[Effect of natural isotope contents of nutrients on the background in 13C breath tests].

The long-term variation of the mean delta 13C-value of breath-CO2 of Europeans (base value -26%) was +/- 1% over a period of several months. However, the ingestion of products from corn, a C4-plant, caused remarkably higher shifts. In a fasted state and during rest a stability of the base value of +/- 0.3% could be attained for several hours. Longer fasting periods imply a shift of the CO2-delta-value due to the metabolism of body products. - By a change of the main energy source to corn products the delta 13C-base line could be shifted to -18% within one day. After this shift even the metabolism of products from C3-plants could be investigated. The degradation curve and the integral degradation of fats were largely dependent on the method of application, and the base value largely interfered with the results. The period of maximum disintegration for a naturally and uniformly labelled fat was different from that of an artificially labelled trilinoleate. The results shall be used for the adjustment and the correction of the base line in 13C-breath tests, especially with patients under parenteral nutrition.

Breath Tests↗
PubMed1983

Xeroradiographic determination of Achilles tendon thickness in familial hypercholesterolemia confirmed by tissue cultures.

Twenty-three patients with familial hypercholesterolemia (FHC) confirmed by tissue cultures of skin fibroblasts (2 homozygotes, 21 heterozygotes) and 3 patients with sporadic hypercholesterolemia were evaluated for Achilles tendon (AT) thickness by xeroradiography. Both homozygotes had thick ATs and coronary heart disease (CHD), 20 heterozygotes had thick ATs, but only 8 of them had CHD. One heterozygote had a small AT value, but CHD for a long time. The 3 patients with sporadic hypercholesterolemia, one with CHD, had small AT. There was no correlation between serum cholesterol concentration and AT thickness, between age and AT thickness, nor between AT thickness and CHD.

Achilles Tendon↗
PubMed1983

Hormonal regulation of lipogenesis in human diploid fibroblasts from normal subjects and from patients with familial hypertriglyceridaemia.

Lipogenesis has been investigated in diploid fibroblasts derived from patients with familial hypertriglyceridaemia (FHT) and compared with cells from healthy persons. There was no difference in acetyl-CoA carboxylase activity in both cell types. Incorporation of [2-14C]-acetate into triglyceride fatty acids was slightly increased (34%) by the FHT lines. Addition of triiodothyronine caused a marked rise in [2-14C]-acetate incorporation by the FHT lines whereas the normal lines exhibited only control values. Maximal rise in [2-14C]-acetate incorporation was obtained with 5 micrograms/ml for 72 h. Under these conditions, acetate incorporation by the FHT lines was 220% of the controls, compared with 94% by the normal lines. Measurements of acetyl-CoA carboxylase specific activity supported the results obtained with measurements of acetate incorporation into triglyceride fatty acids. Individual FHT lines differ much in their quantitative answer to thyroid hormones, although the described effects were obtained with all eight lines under study. Insulin increased acetyl-CoA carboxylase activity and incorporation of [2-14C]-acetate in lipids in both cell types, but with no difference between normal and FHT lines. The results seem to reflect a higher lipogenic capacity of the hypertriglyceridaemic fibroblasts compared with normal cells.

Acetates↗
PubMed1983

[Clearance and utilization of infused fat emulsions].

Fat emulsions are an important source of energy for parenteral nutrition. The utilization of fat emulsions can be differentiated in elimination and oxidation. Biphasic elimination curves are observed, indicating zero order kinetics for removal at high substrate concentrations and first order kinetics at low substrate concentrations. During elimination from plasma apolipoproteins are transferred to the artificial fat particles. The elimination rate is determined by the composition of the fat particles, the nutritional status and the illness of the patient. The oxidation of the infused fatty acids is not strongly correlated with elimination. For clinical purposes the elimination is a suitable parameter for utilization.

Apolipoproteins↗
PubMed1983

[Current status of parenteral feeding with fat emulsions. Clinical experiences with infected patients].

In sepsis the utilization of endogenous and administered fuel sources is sometimes impaired. The precise origin of this metabolic failure is currently unknown. In long term and severe septic processes an increased peripheral energy deficit appears accompanied by a drastically augmented muscle protein catabolism. Branched chain amino acids released by this protein breakdown, at least temporarily, meet the energy needs of the muscles. Ketone bodies as energy source for the muscle are not available because their production is diminished in sepsis. The question of whether or not fat emulsions can be administered to septic patients still remains unanswered, although some recent investigations have demonstrated that fat is utilized and oxidized by septic patients. Results from our patients indicate that a marked reduction of cholesterin ester quotient, an increase of total and VLDL triglycerides and a severe reduction of HLDL Cholesterin are particularly characteristic changes in lipid metabolism during sepsis. The proportional decrease of the linoleic acid levels in cholesterol esters of plasma observed in septic patients was even more pronounced followed severe injury. Together with others we believe that parenteral fat application is not contraindicated in sepsis. The decision to infuse fat emulsions depends more on the metabolic situation of a patient than on a specific diagnosis; in other words, a sufficient peripheral oxygen supply, the level of the serum triglycerides and the reaction of the blood glucose concentration to an intravenously administered fat emulsion are, among others, the decisive factors.

Adult↗
PubMed1982

Prostaglandin formation in man during intake of different amounts of linoleic acid in formula diets.

Prostaglandin formation in healthy female volunteers was investigated during intake of different amounts of linoleic acid in liquid formula diets (LFD). The average amounts of the metabolites convertible to tetranorprostanedioic acid (TNPDA) were 123 +/- 5.2 (x +/- SEM), 175 +/- 7.0 and 352 +/- 10.8 microgram/day, during 2-week periods with a linoleic acid supply of 0, 4 or 20% of energy, respectively. The day-by-day variations in prostaglandin formation were less than the changes observed due to different amounts of linoleic acid. High linoleic acid intake was followed by an increase of TNPDA in the urine after 3-4 days, which was more pronounced when the linoleic acid intake during the period before had been low. In all persons, the highest amount of TNPDA, 411 +/- 13.2 microgram/day, was found between days 5 and 10 of high linoleic acid intake. From day 11 through day 14 an average of 372 +/- 14.3 microgram/day was found and the values were lower in 5 of 6 persons as compared to the values found between days 5 and 10. At the end of the experiment with LFD providing a linoleic acid supply of 0, 4 or 20% of energy, the percentage of cholesteryl linoleate in plasma increased (35 +/- 1.8, 48 +/- 1.0, 63 +/- 0.6) while those of cholesterylarachidonate decreased (14 +/- 1.0, 10 +/- 0.6, 8 +/- 0.6). During the periods without linoleic acid intake the TNPDA excretion was lowest in all persons. A reduction in linoleic acid supply resulted in a decrease of urinary TNPDA within 1 day.

Adult↗