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Biomedical subjects

G Wolfram

Publications and source records attributed to G Wolfram.

At least 127 records · Page 7Linked to original sources
PubMed1988

[Lysosomal enzyme activity of monocytes/macrophages following incubation with postprandial hyperlipemic serum and its significance for the development of atherosclerosis].

Lipid accumulation in macrophages is a prominent feature of the atherosclerotic lesion. Decreased lysosomal function of these cells might play an important role in the pathogenesis of the atherosclerotic foam cell. In this investigation six normal volunteers were fed a meal with a high fat content (68.9% energy, P/S ratio 0.13). The hyperlipidemic postprandial serum was incubated with monocyte derived macrophages. The enzyme activity of cathepsin B, acid cholesterylester-hydrolase and N-acetyl-beta-hydrolase decreased significantly in these cells. Thus, inadequate response in enzyme activity of lysosomal enzymes in case of fat overload might contribute to the development of the atherosclerotic foam cell.

Acetylglucosaminidase↗
PubMed1988

[Phospholipids as emulsifiers in fat emulsions--effect on phospholipids in the serum lipoprotein fraction d greater than 1.063].

Fat emulsions for parenteral nutrition contain phospholipids of different quantity and quality. They are substrates of lecithin-cholesterol-acyltransferase (LCAT). Two fat emulsions commonly used in parenteral nutrition with different emulsifiers (Intralipid 10%, emulsified with egg phospholipid, and Lipofundin S 10%, emulsified with soya phospholipid) were infused into six healthy volunteers. The products of the LCAT reaction were determined in serum lipoprotein fraction d greater than 1.063. Lecithin (16%) as well as lysolecithin (30%) increased by the same amount during a 4-h infusion of each fat emulsion. The concentrations of lecithin and lysolecithin were still within normal ranges after infusion. The percentage of linoleic acid in cholesterol esters in d greater than 1.063 fraction remained unchanged during infusion of soya phospholipids and decreased 5% during infusion of egg phospholipids. The results indicate an equal LCAT activation by both fat emulsions in man.

Adult↗
PubMed1988

Utilization of medium-chain triglycerides and octanoic acid by cultured human fibroblasts and lymphoblasts.

Cultured human fibroblasts and lymphoblasts were incubated with emulsions containing 14C-trioctanoin or 14C-tripalmitin. Both cell types were able to hydrolyse the medium-chain triglyceride but not the long-chain triglyceride to the corresponding fatty acids. At the end of a 3 days incubation period, 25-30% of the initial amount of 10 nmol/ml trioctanoin were present as triglyceride. The observed hydrolysis seems to be mediated by an esterase secreted into the culture medium, as was shown by the use of cell-conditioned medium. CO2 production from octanoic acid was below 2 nmol per mg protein and day, demonstrating that these cells have a low capacity to use this substrate for their energy metabolism.

Animals↗
PubMed1988

Evidence for a nonspecific factor interfering in the radioimmunoassay of somatoliberin-like immunoreactivity in human seminal plasma.

In the present study we investigated the nature of somatoliberin-like immunoreactivity in human seminal plasma. In unextracted seminal plasma, somatoliberin-like immunoreactivity represented 3.8 micrograms/l somatoliberin, with a dilution curve that ran almost completely parallel to that of synthetic somatoliberin standard. After extraction by adsorption on hydrophobic C 18 Sep-pak cartridges or immunoaffinity chromatography, no somatoliberin-like immunoreactivity in seminal plasma could be detected. After gel permeation chromatography on a Sephadex G-50 fine column, all somatoliberin-like immunoreactivity of unextracted seminal plasma was recovered at the void volume of the column. When equal volumes of unextracted seminal plasma and radioiodinated somatoliberin were coincubated for two days at 4 degrees C, gel chromatography revealed the disappearance of the normal [125I]somatoliberin peak, replaced by a new peak eluting shortly after the total volume of the column. When unextracted seminal plasma was heated at 90 degrees C for 10 min or submitted to ultrafiltration, the interfering factor was no longer detectable. Our data show that enzymic degradation of radioiodinated somatoliberin led to misleadingly high concentrations of somatoliberin-like immunoreactivity in seminal plasma. These phenomena should therefore be considered when performing radioimmunoassays of short chain peptides in biological fluids.

Chromatography, Affinity↗
PubMed1987

[Effects of equal amounts of linoleic acid in orally administered, polyunsaturated phospholipids or in safflower oil on blood lipoproteins].

The effects of polyenylphosphatidylcholine in a dosage of 10 g per day were compared with an equimolar amount of linoleic acid in 7 g safloroil per day in 8 healthy subjects for 3 weeks. The concentrations of cholesterol, triglycerides, phospholipids, apolipoproteins A-I, A-II and B were measured in serum, as well in VLDL, LDL, HDL, HDL2, HDL3 on the day before, after 2 and 3 weeks of application and 6 months after the experiment. The diet was controlled 10 days before and during the experiment using the dietary recall method. According to the dietary records there was an increase of fat supply during application of polyenylphosphatidylcholine inhibiting decrease of LDL cholesterol, which was observed with safloroil. Phospholipid concentrations increased significantly with polyenylphosphatidylcholine in VLDL. Apolipoprotein B in LDL was significantly decreased by both substances. Apolipoprotein A-I and A-II in HDL increased significantly with polyenylphosphatidylcholine. With safloroil this effect was limited to apolipoprotein A-I, but less impressive. The effects of both substances are comparable in the decrease of apolipoprotein B and probably cholesterol. A special effect of polyenylphosphatidylcholine was observed on phospholipids in VLDL and on apolipoprotein A-I and A-II in HDL.

Administration, Oral↗
PubMed1987

[Decrease of serum lipoproteins and increase in apolipoproteins A-I and A-II following oral administration of multiple unsaturated phospholipids. Observations on the effect of nutrition on the results].

Polyenylphosphatidylcholine was given orally in a dosage of 10 g per day to 10 healthy subjects for 4 weeks. The concentrations of cholesterol, triglycerides, phospholipids, apolipoproteins AI, AII, and B were measured in serum, as were very low density lipoproteins, low density lipoproteins, and high density lipoproteins every 3 h on the day before and after the 4 weeks of application. The diet was controlled 10 days before and during the experiment using the dietary recall method. The evaluation of the diet records showed that 5 subjects had increased and 5 subjects had decreased their fat consumption in exchange for carbohydrates during the experiment. Nevertheless body weight remained constant within +/- 1 kg. Cholesterol in serum and low density lipoprotein decreased, but the differences were not statistically significant. In spite of dietary changes apolipoprotein AI and AII in high density lipoproteins increased significantly. We conclude that the influence of drugs on serum lipids can only be evaluated in conjunction with reliable control of the diet.

Administration, Oral↗
PubMed1987

Alteration of oral carbohydrate tolerance during administration of a fiber-free formula diet.

Fiber-free formula diets are widely used for medical and experimental purposes. In healthy individuals no major changes of fasting blood glucose have been reported, whereas oral glucose tolerance tests indicate a deterioration of carbohydrate tolerance following ingestion of liquid diets containing certain sugars. We examined carbohydrate tolerance in normal subjects during prolonged administration of a fiber-free semisolid diet containing polysaccharides instead of sugars. In the first experiment, diet A (55% starch, 40% highly polyunsaturated fat, P/S 5.4, 15% protein) served as the sole source of energy for 4 weeks. During this time a progressive deterioration of carbohydrate tolerance was observed, indicated by a gradual increase of the postprandial glycemic response (area under the curve) from -316 to +3874 mg/dl X min without significant alteration of postprandial serum insulin concentrations. For the second study, nutrient relations of the diet were modified (diet B: 45% starch, 40% saturated fat, P/S 0.3, 15% protein). The changes of carbohydrate tolerance during 1 week of feeding diet B were similar to those seen in the first experiment. However, follow-up observations during a subsequent pharmacological trial showed that the changes of postprandial blood glucose curves were reversed within 2 weeks. This was associated with an enhanced serum insulin response. The reason for the different durations of the metabolic effects of diets A and B are not obvious from our data. The time course may have been influenced by the different nutrient intake. Fasting blood glucose concentrations were not sensitive enough to detect the deterioration of carbohydrate tolerance.

Adult↗
PubMed1987

Atherosclerosis of the carotid arteries documented by duplex scan as a predictor of coronary artery disease in familial hyperlipidemias.

The degree of atherosclerotic plaques in the carotid arteries was evaluated in 85 patients with familial hypercholesterolemia and in 43 patients with familial combined hyperlipidemia by means of Duplex scan which recognizes early atherosclerosis. In patients older than 40 years carotid atherosclerosis of moderate degree was associated with coronary heart disease in 90% of cases. The extent of elevated cholesterol, age, cigarette smoking, and hypertension determined the degree of carotid atherosclerosis.

Adolescent↗
PubMed1987

[Determination of purine compounds and purine bases in food].

The total purine content and the content of RNA, DNA, nucleotides, nucleosides and free purine bases has been determined in commercial raw food. After hydrolysing food samples with acid, the total purine content is enzymatically determined as uric acid. For the determination of the nucleic acid content, a method is chosen that allows for the analysis of the composition of nucleic acids. The amount of purine bound in nucleic acids and of purine bound in nucleotides, nucleosides and free bases is very different. The content of nucleic acids is especially high in the innards of veal, pork and beef. In these samples the quantity of purine bound in nucleotides, nucleosides and bases is very small. In trout and herring, however, more purine is bound in RNA and DNA. The same is true of roe, pork and beef muscle. Peas and beans have the lowest total purine content of all the samples examined.

Animals↗
PubMed1987

[Total purine content in selected foods].

For the dietary treatment of hyperuricemia and gout, it is necessary to know the total purine content of food. A new method determining the purine content enzymatically, as uric acid, allows routine analysis. Many foods of animal and plant origin were brought in usual or alternative stores and analysed.

Food Analysis↗
PubMed1987

[Effect of cooking on the purine content of foods].

The total purine content and the content of purines bound in RNA and DNA was determined in selected food (veal meat, pork meat, pork liver, pork spleen, soja meat). Raw and boiled food samples were analysed. During preparation of food the total purine content is changed by losses of water or of purines into cooking water. Simultaneously, a great part of nucleic acids is hydrolysed.

Animals↗
PubMed1987

[Effect of DNA and RNA in foods on serum uric acid concentration in the human].

Nutritional experiments with formula diets show, that DNA taken orally raises the serum uric acid concentration only half as much as does the same quantity of RNA. In evaluating the suitability of foods used in the diet of patients with gout, however, food is only judged by its total purine-N content. In commercially available raw food the total purine content was determined enzymatically as uric acid. In the same samples the content of RNA, DNA, nucleotides, nucleosides and bases was determined. Eight healthy persons took part in a nutritional experiment, which began with a diet low in purines. During the first phase of the experiment, the participants ate 150 g veal-liver in addition to the low purine diet; in the second phase, they ate 80 g pork-spleen. In both additional foods, subjects took in an equal amount of total purines, determined as uric acid, but RNA dominated in veal-liver, DNA in pork-spleen. There was no statistically significant difference in the effect on serum uric acid concentration and urinary uric acid excretion between eating liver and spleen, however.

Adult↗
PubMed1987

[Salivary LH as an ovulation indicator: comparison between salivary LH, serum LH and ultrasonic findings].

A radioimmunological method of salivary LH determination has been developed as a new non invasive approach to hormonal ovulation detection. In this study salivary LH patterns have been compared to serum LH peak and daily sonographic assessment of follicle maturation in 15 spontaneous cycles of 9 women experienced in self-observation of their cycles (NFP). The day where the mature follicle was no longer visible sonographically was labelled day 0. Serum LH peaks occurred in 11 out of 15 cycles on day -1, two times on days -2 and 0 and preceded salivary LH peaks in 8 out of 15 cycles. The latter coincided in 7 cycles with day 0 in two cycles each with days -1 and +1 and in 4 cycles with day -2. Thus 13/15 serum- and 11/15 salivary-LH peaks occurred within +/- one day of the disappearance of the mature follicle. A time lag of up to six hours between the sampling of saliva and serum might explain the difference in the respective peak days, however, more studies into the kinetics of LH transport and its circadian rhythmicity seem necessary. Nevertheless, in principle also the salivary LH peak is considered a suitable indicator of ovulation.

Adult↗
PubMed1987

[Salivary LH as an ovulation indicator: on the value of autopalpation of the cervix uteri for the detection of fertile and infertile days of the cycle].

The validity of autopalpation of the cervix as an indicator of fertility has been studied in 115 cycles of 13 nulliparous and 13 parous women, aged 22 to 35 years and experienced in self-observation methods (SOM) of family planning. For this purpose, the reported cyclic changes of the cervix uteri (hard, closed and low positioned; soft, open and higher positioned or intermediate stages) have been compared with the salivary LH-peak as indicator of ovulation, the BBT-readings and cervical mucus quality. The study has confirmed that in principle it is possible to collect sufficiently reliable self observation data for family planning purposes by autopalpation of the cervix. Parous women detect the first preovulatory changes of the cervix earlier and more frequently than nulliparous. Nevertheless it is not possible for either group to determine the beginning of the fertile days in this way. The beginning of the postovulatory infertile phase, however, can be detected: if, in accordance with rising BBT, the cervix has returned to a hard and closed appearance for 4 days, this symptom signals infertility with the same high degree of accuracy as the third measurement of elevated BBT (BBT3). Thus a "rule of thumb" can be established, linking the beginning of postovulatory infertility to either the fourth day of the hard and closed cervix or to the evening of the day of BBT3, "whatever comes first". In this way, the beginning of the infertile phase could be recognized one to three days earlier by referring to the cervix in about 20% of the cycles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Changes in serum lipoproteins in humans following the infusion of a fat emulsion containing medium- and long-chain triglycerides.

A fat emulsion containing equal parts of medium-chain triglycerides (MCT) and long-chain triglycerides (LCT) and emulsified with egg phospholipids (Lipofundin MCT 10%) was compared with LCT emulsions (Intralipid 10%, egg phospholipids; Lipofundin S 10%, soya phospholipids) in six volunteers, using 4-h periods of infusion and doses of 0.15 g kg-1 body h-1. At the end of infusion very low density lipoprotein (VLDL) triglyceride concentrations were highest with Intralipid, marginally less with Lipofundin MCT and lowest with Lipofundin S. With Lipofundin MCT infusion the proportions of free medium-chain fatty acids in serum reached 30%. In VLDL the ratios triglycerides/apolipoprotein B and triglycerides/phospholipids rose most after Lipofundin MCT and least after Lipofundin S. With Lipofundin MCT and Intralipid, surface components in low density lipoproteins (LDL) are lessened in relation to the internal components; this does not occur with Lipofundin S. High density lipoprotein (HDL) subfractions are influenced in identical directions by all fat emulsions with exception of a single increase of phospholipids in (HDL3) after Lipofundin MCT.

Adult↗