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Biomedical subjects

J Boberg

Publications and source records attributed to J Boberg.

At least 55 records · Page 3Linked to original sources
PubMed1978

Para-aminosalicylic acid as a lipid-lowering agent.

The capacity of para-aminosalicylic acid (PAS) to lower initially high serum lipoprotein lipid concentrations was tested in a double-blind crossover study. Thirty patients who were on a lipid-lowering diet were treated with PAS (6 gm daily) for 4 wk. There was an average reduction of the serum triglyceride concentration of 28% (p less than 0.001) and of 12% of the serum cholesterol concentration (p less than 0.001) corresponding to a reduction of very low density lipoprotein (VLDL) triglycerides of 40% (p less than 0.001) and low density lipoprotein (LDL) cholesterol of 6% (p less than 0.05). In hypercholesterolemic patients, the LDL cholesterol reduction was 14% (p less than 0.001). In patients with hypertriglyceridemia type IV, the mean reduction of the VLDL triglyceride concentration was 47% (p less than 0.01), corresponding to a serum triglyceride reduction by 37% (p less than 0.01). In spite of the decrease of VLDL concentration, there was an unexpected reduction of the lipoprotein lipase activity in adipose tissue of 16% (p less than 0.02). The glucose tolerance and the serum insulin concentrations at fasting and after glucose injection were not changed.

Adipose Tissue↗
PubMed1978

Lipoprotein-lipase activity in human skeletal muscle and adipose tissue in the fasting and the fed states.

Sixteen healthy subjects, 7 females and 9 males, with a mean age of 25 years (range 22--29 years), were studied in the fasting state in the morning and 8 h later after partaking of breakfast, lunch and two small meals. The lipoprotein-lipase activity in the adipose tissue increased significantly from 80 +/- 32 to 117 +/- 61 nmol fatty acid released per gram and minute (nmol FA/g/min), whereas in skeletal-muscle tissue it decreased significantly from 25 +/- 11 to 17 +/- 9 nmol FA/g/min. The concentration of serum triglycerides increased significantly from 0.93 +/- 0.18 mmol/l (mean +/- SD) in the fasting state to 1.57 +/- 0.64 mmol/l in the fed state. In the fasting state the lipoprotein-lipase activity of skeletal muscle was inversely related to the ratio between the concentrations of insulin and glucagon.

Adipose Tissue↗
PubMed1978

Lipolytic activities in post-heparin plasma in man measured with different substrate emulsions.

1. Post-heparin lipolytic activity in man has been studied by using a triglyceride substrate emulsion containing different emulsifiers. 2. The lipolytic activity measured was profoundly influenced by the type of emulsifier used in the substrate. Substrate stabilized by synthetic emulsifiers give higher lipolytic activity than Intralipid, which contains egg phospholipids as emulsifiers. This difference was solely explained by higher salt-resistant lipase activities found with emulsions containing synthetic emulsifiers. The salt-inhibited lipase activity, which has properties as a lipoprotein lipase, was not influenced by the type of emulsifier. 3. When used under specified conditions Intralipid seems to be virtually specific for extrahepatic post-heparin lipolytic activity.

Emulsions↗
PubMed1978

Increase of the lipoprotein-lipase activity in human skeletal muscle during clofibrate administration.

Lipoprotein-lipase activity was determined in tissue from the skeletal muscle of the leg and the subcutaneous adipose tissue of the abdomen in fourteen patients before and after 1 month of clofibrate administration. The concentrations of serum triglycerides decreased by, on the average, 37% in a group of thirteen patients which mainly consisted of subjects with type-IV hyperlipoproteinaemia. Clofibrate administration was associated with an average increase of the skeletal muscle-tissue lipoprotein-lipase activity of 50% (P less than 0.005). There was a significant correlation between the percentage changes in skeletal muscle-tissue lipoprotein-lipase activity and those of the triglycerides concentrations and the K2-values in an intravenous fat tolerance test during clofibrate treatment. Adipose-tissue lipoprotein-lipase activity did not change significantly. One patient with type-I hyperlipoproteinaemia had very low values of skeletal muscle-tissue lipoprotein-lipase activity and moderately low adipose-tissue lipoprotein-lipase activity. In this patient, neither the tissue lipoprotein-lipase activity nor the triglycerides concentration changed during clofibrate therapy. Fasting serum insulin concentrations decreased significantly during clofibrate administration and the percentage decrease was significantly correlated to the percentage increase of skeletal-muscle lipoprotein-lipase activity. It is suggested that the lowering of insulin levels is a possible mechanism through which glucagon activity is enhanced and this may increase skeletal muscle-tissue lipoprotein-lipase activity.

Adipose Tissue↗
PubMed1978

Lipoprotein-lipase activity in subcutaneous, adipose tissue in healthy subjects: variation of activity in a population of 60-year-old men.

The lipoprotein-lipase activity (LPLA) in the abdominal, subcutaneous, adipose tissue was studied in a random sample (n = 69) of 60-year-old men. A new method for the quantification of LPLA was applied. The mean value was 67 mU/g when expressed per gram (wet weight) of adipose tissue. Several subjects within the lower part of the range of adipose-tissue LPLA values had low concentrations of serum-triglycerides (S-TG). There was no correlation between the LPLA and S-TG concentrations in the fasting state. Among the 69 subjects, four had newly detected diabetes mellitus and had significantly lower LPLA in the adipose tissue than the control group. The fat-cell size and the LPLA per gram of adipose tissue were not correlated. Thus, obesity without diabetes mellitus does not imply a low LPLA concentration in adipose tissue. The variation of the concentration of adipose-tissue LPLA in the fasting state in this population was explained only to a minor extent by the variation of S-insulin and blood-glucose parameters, when analysed statistically by a stepwise multiple-regression technique.

Abdominal Muscles↗
PubMed1978

The lipoprotein-lipase activity of adipose tissue from different sites in obese women and relationship to cell size.

The lipoprotein-lipase activities (LPLA) and fat cell sizes were determined in subcutaneous, adipose tissue from four different sites in a group of 17 obese women. The LPLA per gram and per cell were significantly higher in the adipose tissue from gluteal and femoral sites than in tissue from the abdominal site. The degree of obesity of the subjects, as reflected in the fat cell size, was correlated with the LPLA per cell, so that large cells contained more LPLA per cell than small cells. On the other hand, no correlation was found between the cell size and the LPLA per gram. Intra-individually, the cell weight was related also to the LPLA per gram, so that sites with large fat cells also had high concentrations of LPLA per gram. The interpretation of the results with regard to obesity and to the variation in size of fat depots in an individual is discussed.

Adipose Tissue↗
PubMed1977

The effect of treatment with clofibrate on hepatic triglyceride and lipoprotein lipase activities of post heparin plasma in male patients with hyperlipoproteinemia.

Twelve male patients with hyperlipoproteinemia were treated with clofibrate, 1 g twice daily. Serum triglyceride concentration decreased on the average 28 +/- 6%. No significant change of serum cholesterol concentration occurred. Post heparin plasma lipoprotein lipase activity isolated and partially purified by heparin Sepharose affinity chromatography was determined quantitatively. During the clofibrate treatment this enzyme activity increased 48 +/- 9%. The post heparin hepatic triglyceride lipase did not change significantly. The possibility that the serum triglyceride-lowering effect of clofibrate might partly be explained by an increased removal rate of triglyceride rich lipoproteins through increased lipoprotein lipase activity is discussed.

Adult↗
PubMed1977

Supplementation with vitamin E in hyperlipidemic patients treated with diet and clofibrate. Effects on serum lipoprotein concentrations, plasma fatty acid composition and adipose tissue lipoprotein lipase activity.

Twelve hyperlipidemic patients on long term treatment with a lipid lowering diet enriched in polyunsaturated fatty acids and with clofibrate were supplemented with vitamin E (400 mg/day). The effect on serum lipoprotein concentration, plasma lipid fatty acid composition, and adipose tissue lipoprotein lipase activity was studied. No additional lipid-lowering effect was registered during a treatment period of 4 months. A slight increase in total serum cholesterol concentration and in high density lipoprotein concentration was probably attributable to seasonal variations in serum lipoprotein concentrations. No major changes of fatty acid composition in plasma cholesteryl esters or triglycerides were recorded. However, an increased relative amount of arachidonic acid and a reduced amount of palmitic acid in the plasma phospholipids after 2 months was possibly caused by the vitamin E therapy.

Adipose Tissue↗
PubMed1977

A method of determining lipoprotein-lipase activity in human adipose tissue.

A method of determining lipoprotein-lipase activity (LPLA) in human adipose tissue specimens (weighting 5-50 mg) is described. The specimens were incubated at 37 degrees C in a reaction medium based on a glycine buffer (pH 8.3, ionic strength 0.08), in which the enzyme was stablized and the velocity of release of fatty acids was constant during the incubation. The enzyme activity was increased, as is characteristic of lipoprotein-lipase (LPL), three to four-fold by the addition of serum. The inhibitions by NaCl, protamine sulphate and apolipoprotein C-III were as for LPL, when analysed in both a serum-activated and non-activated reaction medium. The apparent LPLA was about six times greater when analysed in a reaction medium based on a glycine buffer in the presence of heparin (1 g/l) than when analysed in a reaction medium based on a Tris buffer. An analysis of the influence of a high (1 g/l) and a low (0.05 g/l) concentration of heparin on the properties of the enzyme activity was carried out, using LPL of bovine skim milk as a reference enzyme. A phospholipid/soybean-oil emulsion was used as substrate, with [3H]triolein as a trace substance. The emulsion was stable for 5 months. The adipose tissue specimens were stored in liquid nitrogen. The analytical error was 15%, which was reduced to 11% (=within-day variation) when intra-individual comparisons were made.

Adipose Tissue↗
PubMed1977

Quantitative determination of hepatic and lipoprotein lipase activities from human postheparin plasma.

A method was developed to separate and quantitatively determine two different triglyceride lipase activities in human postheparin plasma: hepatic triglyceride lipase (H-TGL) and lipoprotein lipase (LPL). Affinity chromatography on heparin-Sepharose columns was used for the separation. Rechromatography of purified H-TGL on heparin-Sepharose resulted in recoveries of 74 and 97% of these enzyme activities, respectively. The analytical errors for the determinations of the two activities were 11.4 and 9.6%, respectively.

Female↗
PubMed1976

The early serum insulin response to intravenous glucose in patients with decreased glucose tolerance and in subjects with a familial history of diabetes mellitus.

Intravenous glucose tolerance tests with estimations of K values and measurements of serum insulin concentrations at 0, 4, 6, and 8 min after the start of the glucose injection were performed in connection with a health examination survey of middle-aged men. The possible predictive value for later diabetes mellitus of early serum insulin response after intravenous glucose administration was evaluated by studying subjects with a familial history of diabetes mellitus and patients with different degrees of glucose intolerance. The following conclusions were drawn: The early appearance of glucose-stimulated serum insulin should be studied during the first 6 min after start of the glucose injection. The advantage of making calculations for early insulin secretion by including approximate considerations of the fractional removal rate of serum insulin is not apparent. Serum insulin values in patients with decreased glucose tolerance and subjects with a familial history of diabetes mellitus were best characterized by an insulin concentration index (glucose-stimulated early serum insulin concentration divided by basal serum insulin concentration). This index was significantly lower in these groups than in healthy controls.

Diabetes Mellitus↗
PubMed1976

Gemfibrozil as a lipid lowering compound in hyperlipoproteinaemia. A placebo-controlled cross-over trial.

The efficacy of gemfibrozil in lowering increased serum lipoprotein concentrations was tested in a placebo-controlled cross-over trial on 30 patients. Administered in a dose of 1200 mg daily, gemfibrozil reduced increased serum triglyceride levels by approximately 50% and reduced increased serum cholesterol concentrations by about 20%. Elevated VLDL triglyceride levels were reduced by 60%, and increased LDL cholesterol concentrations were reduced by approximately 20%. The mean HDL cholesterol concentration increased during gemfibrozil treatment. No adverse reactions attributable to gemfibrozil were recorded during the trial.

Adipose Tissue↗
PubMed1975

Statistical analysis of the reproducibility of the intravenous glucose tolerance test and the serum insulin response to this test in the middle-aged men.

The reproducibility of the intravenous glucose tolerance test (IVGTT) and the serum insulin response to this test have been studied in 48 healthy middle-aged men participating in a health screening program. Two tests were done 4-6 weeks apart. The subjects were ambulatory, and no diet prescriptions other than recommendation of an overnight fast were given. Under these circumstances the correlation between the K values of the two tests was low (r equals 0.55), and the equation for linear regression was y equals 0.56 x + 0.61. The intraindividual variation was 21 per cent, expressed as the coefficient of variation. The early increases in glucose-stimulated serum insulin concentrations in the two tests were significantly correlated (r equals 0.87), and this equation for linear regress was y equals 0.81 x + 10. The coefficient of variation intraindividually for this determination was 20 per cent. We conclude that the K values of the IVGTTs must be judged with caution when obtained in ambulatory practice, especially when the result is used for preventive measures and long-term follow-up of asymptomatic individuals.

Clinical Trials as Topic↗