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Biomedical subjects

L A Carlson

Publications and source records attributed to L A Carlson.

At least 145 records · Page 8Linked to original sources
PubMed1977

Effect of BM 15.075 on lipoprotein concentrations in different types of hyperlipoproteinaemia.

The four-week lipoprotein lowering effect of 0.2 g t.i.d. of BM 15.075 and of 0.5 g t.i.d. of clofibrate was studied in 29 subjects with different types of hyperlipoproteinaemia in a single blind crossover fashion. BM 15.075 decreased very low density lipoproteins (VLDL), triglycerides (TG) and cholesterol concentration in all types of hyperlipoproteinaemia the effect being dependent on initial lipoprotein concentrations. BM 15.075 decreased VLDL triglyceride concentrations on average 20% more than did clofibrate. BM 15.075 decreased low density lipoproteins (LDL) cholesterol concentrations in Type IIA and IIB but did not significantly affect this lipoprotein lipid in type IV hyperlipoproteinaemia. Regression analysis showed that the drug tended to decrease LDL cholesterol if initial concentrations were above 157 mg/100 ml and to increase initially lower levels. No significant differences between BM 15.075 and clofibrate was found in the effect of LDL cholesterol. High density lipoproteins (HDL) cholesterol concentrations were not influenced by BM 15.075. No subjective side effects were noted on BM 15.075. S-ASAT increased and alcaline phosphatases decreased on both treatments.

Benzamides↗
PubMed1977

On the rise in low density and high density lipoproteins in response to the treatment of hypertriglyceridaemias in type IV and type V hyperlipoproteinaemias.

In Type V hyperlipoproteinaemia the concentration of LDL and HDL cholesterol is low. When the hypertriglyceridaemia is normalized, either by diet or micotinic acid, both LDL and HDL increase. In Type IV hyperlipoproteinaemia both LDL and HDL cholesterol decrease with increasing VLDL levels. During treatment of Type IV the change in LDL cholesterol is linearly related to the pretreatment LDL concentration so that higher LDL levels will fall and the lower will rise. HDL levels will also rise. The fall in VLDL during treatment is rapid and the rise in LDL also occurs rapidly indicating a relationship between these two reciprocal changes. HDL cholesterol, however, however, remains constant some time after VLDL has reached its lowest level and the rise occurs later indicating another mechanism than for LDL. These changes in the three major lipoprotein classes deserve clinical attention. While both the fall in VLDL and the rise in HDL may be benefical from the point of view of atherosclerosis the rise in LDL may be harmful. These is at present no way to evaluate the effect of these complex changes. However, these findings stress the imporance of considering changes in lipoprotein levels and not only in total serum triglycerides and cholesterol during treatment of hyperlipoproteinaemia.

Cholesterol↗
PubMed1977

Reduction of myocardial reinfarction by the combined treatment with clofibrate and nicotinic acid.

In an ongoing study 558 consecutive survivors of myocardial infarction below 70 years, mean age 59 years, were randomly allocated 4 months after the acute episode into a control group or a chemotherapy group from December 1972 to April 1976. Both groups were given moderate advice about diet and the chemotherapy group was prescribed clofibrate, 1 g twice daily, and nicotinic acid 1 g three times daily. Serum cholesterol and triglycerides were lowered around 15-20% and 30% respectively in the chemotherapy group while only insignificant reductions were observed in the control group. Until December 1976 total mortality and mortality from IHD has been the same in the two groups. The number of non-fatal myocardial infarctions has been 38 in the control and 19 in the chemotherapy group, a statistically significant reduction (P less than 0.01).

Cholesterol↗
PubMed1977

Decrease in alpha-lipoprotein cholesterol in men after cessation of exposure to chlorinate hydrocarbon pesticides.

Eight men who in 1970 had been exposed to chlorinated pesticides and for whom the exposure had ceased in 1976, showed a significant fall in alpha-lipoprotein (HDL) cholesterol between these years. The cholesterol concentration of the other lipoprotein classes showed no significant trend. The data support our previous suggestion that exposure to chlorinated pesticides, mainly lindane, may raise the alpha-lipoprotein levels.

Cholesterol↗
PubMed1977

Sex differences in serum lipids and lipoproteins at birth.

In a study of 1426 males and 1391 females at birth the mean concentrations of cholesterol in total serum, in the sum of very low density and low density lipoproteins and in high density lipoprotein were significantly higher in females than in males. No sex difference was present in the concentration of triglycerides either in total serum or in the lipoprotein fractions.

Cholesterol↗
PubMed1977

Differences in heparin-released lipolytic activity in the superficial and deep veins of the human forearm.

Various doses of heparin were given as a single injection into the brachial artery of each of twelve fasting healthy males. Plasma lipolytic activity was measured in samples obtained before and at frequent time intervals after heparin injection, in the artery and the deep and superficial veins of the same forearm. As little as 0.15 U heparin produced a rapid and detectable release of lipolytic activity in both deep and superficial veins. A series of tenfold increases in the dose produced correspondingly greater releases in the veins but the increments in the release were smaller than the increments in the dose. Three repeated 15 U doses of heparin, separated by 30 min, in the same subject gave a high degree of reproducibility of the release of lipolytic activity in both deep and superficial veins. 90% of the lipase activity in the vein was inhibited by 1 M NaCl. In all subjects the release of lipolytic activity was higher in the deep vein, which predominantly drains muscle, than in the superficial vein, which drains mostly subcutaneous tissues such as skin and adipose tissue. This indicates that muscle is a tissue of considerable importance as a source of post heparin plasma lipolytic activity.

Adipose Tissue↗
PubMed1976

Fatty acids incorporation into human adipose tissue in hypertriglyceridaemia.

The fatty acid and glucose incorporation into glycerides and glycerol release from adipose tissue were determined in a middle-aged population of 109 men and 41 women. 43 men and 19 women were normolipidaemic. The same analysis was also carried out in 13 male and 9 female normolipidaemic students. Needle biopsy specimens of adipose tissue were incubated in vitro in an albumin medium containing 3H-fatty acids and 14C-glucose. After two hours of incubation values for fatty acid and glucose incorporation were calculated from the incorporation of 3H-activity into the fatty acids and 14C-activity into the glycerol moiety of extracted glycerides. The mean values for fatty acid incorporation were lower in all types of hypertriglyceridaemic subjects (II B, III, IV and V) than in the normolipidaemic control subjects. In the male hypertriglyceridaemic population 36% had values for fatty acid incorporation below the 5th percentile of the normolipidaemic group and 14% had values below the lowest normal value. The rate of fatty acid incorporation was negatively correlated with the serum triglyceride concentration. This correlation remained unchanged when partial correlation was performed when the influence of body weight was eliminated. Fatty acid and glucose incorporation correlated positively. Incorporation of glucose behaved in the same way as described above for incorporation of fatty acids. Glycerol and fatty acid release was the same in the normo- and hypertriglyceridaemic groups. It is likely that the removal of plasma triglycerides from blood requires hydrolysis of triglycerides to fatty acids and the subsequent removal of the fatty acids. The hypothesis has been formulated that when the former process is normal, a defect of fatty acid removal (a low rate of fatty acid incorporation into glycerides) may be responsible for an impaired removal of plasma triglyceride-fatty acids. A low rate of fatty acid incorporation may contribute to the development of hypertriglyceridaemia, according to this hypothesis.

Adipose Tissue↗
PubMed1976

Arterial concentration and forearm extraction of glucose and insulin during the early phase of a glucose infusion.

The concentrations of glucose and insulin were determined with high precision at half minute intervals in arterial and deep forearm vein blood after a bolus injection of glucose (4 g), followed by a constant i. v. infusion (200 mg/min), in four healthy subjects. The values for the deep vein were corrected for the transit time, which was determined by injection of Cardio-green. Arterial glucose peaked at the end of the bolus injection, venous glucose 1 1/2 min later. Arterial insulin reached its maximum later than glucose, after 2 1/2-4 min. The venous insulin reached its maximum later and was much lower than the arterial level, in two cases only around 50% of the arterial concentration. It is concluded that early after glucose administration there is a considerable extraction of both glucose and insulin by the forearm. Since the insulin extraction was quite variable venous insulin concentrations cannot be used for the assessment of early insulin response to glucose.

Adult↗
PubMed1976

Serum lipids in alcoholics.

Fasting serum lipid values (cholesterol, triglycerides and phospholipids) have been analysed in a group of 85 male and 10 female alcoholics of various ages in connection with an acute drinking bout and compared to the values of twice as many control subjects. The most prominent finding was an increase in the mean concentration of triglycerides and phospholipids, most marked in the younger age groups. The elevations, however, were moderate and most alcoholics had the same serum lipid values as the controls. Serum triglyceride values above 2 and 3 mmol/1, respectively, occurred in 23% and 4% in controls and in 28% and 13% in alcoholics. It is suggested that excessive intake of alcohol induces hypertriglyceridaemia only when other factors are present. One such factor may be a reduced i.v. fat tolerance.

Adult↗
PubMed1976

Serum lipid and lipoprotein concentrations in chronic uremia.

The concentrations of triglycerides and cholesterol have been determined in total serum and in the three major serum lipoprotein classes--very low (VLDL), low (LDL) and high (HDL) density lipoproteins-after an overnight fast in 39 patients with chronic uremia of more than 2 years' duration and with serum creatinine above 350 mumol/l. The values were compared with data from healthy male and female controls. The findings were similar for male and female uremics. Hypertriglyceridemia was common while serum cholesterol tended to be normal or subnormal. With the conventional typing system for hyperlipidemia, types II A, III and IV were present in 6,9 and 30%,respectively. The tryglyceride and cholesterol concentrations in VLDL were increased, while their normal relation for this lipoprotein class was maintained. In LDL the concentration of tryglycerides was increased, while that of cholesterol was low. The LDL composition, therefore, was changed to be more triglyceride-rich than normal. The changes in concentration and composition of LDL indicated that the levels of LDL 1 were raised and of LDL 2 decreased in chronic uremia. Increased levels of LDL tryglycerides occurred more frequently (40%) than increased levels of VLDL triglycerides (33%). The most striking and consistent lipoprotein abnormality was a low HDL cholesterol, which was not related to high VLDL levels. The HDL tryglycerides, on the other hand, tended to be somewhat high. The importance of the raised levels of the triglyceride-rich VLDL and LDL 1 and the decreased levels of HLD cholesterol for the rapid development of atherosclerotic vascular diseases which occur in chronic uremia is discussed. It is of interest in this context that both total cholesterol and LDL cholesterol were low. The possible mechanisms underlying the lipoprotein abnormalities in chronic uremia are discussed and it is suggested that they are complex.

Adult↗
PubMed1976

Effect of gemfibrozil in vitro on fat-mobilizing lipolysis in human adipose tissue.

Fat-mobilizing lipolysis was studied in rat and human adipose tissue during incubation in vitro by following the release of glycerol into the incubation medium. Gemfibrozil as well as clofibrate consistently and readily inhibited basal as well as noradrenaline-stimulated fat-mobilizing lipolysis in rat fat. With human adipose tissue no effect was observed with gemfibrozil and clofibrate on basal lipolysis. This may be due to the comparatively low rate of the nonstimulated fat-mobilizing lipolysis in human tissue incubated in vitro. When lipolysis was stimulated with noradrenaline as well as isoprenaline, however, both gemfibrozil and clofibrate significantly reduced the fat-mobilizing lipolysis. This inhibition of lipolysis was however not observed in all studies. When lipolysis had been stimulated with theophylline, no inhibition of lipolysis was obtained with either compound. The possibility that reduced fat-mobilizing lipolysis in adipose tissue may cause a lowering of plasma triglycerides by reducing the flow of FFA to the liver is discussed in some detail. It is also suggested that inhibition of lipolysis may be accompanied by increased activity of lipoprotein lipase as well as an increase in the FIAT process. However, the pharmacological implication of the above-mentioned findings, particularly for gemfibrozil, must await further studies, as fairly large doses, around 1 mg/ml of incubation medium, were needed to obtain inhibition of fat-mobilizing lipolysis.

Adipose Tissue↗
PubMed1976

Effect of gemfibrozil on lipoprotein concentrations in different types of hyperlipoproteinaemia.

The lipoprotein lowering effect of gemfibrozil, 400 mg twice daily, was studied for 24 weeks in 26 subjects with primary hyperlipoproteinaemia (type IIa, 5; IIb, 3; III, 3; and IV, 15). Maximum effects were noted after four weeks on very low density lipoproteins (VLDL) and after 12 weeks on low density lipoproteins (LDL), these effects remaining throughout the study. Gemfibrozil decreased VLDL triglycerides (TG) in all types of hyperlipoproteinaemia according to the equation: deltaVLDL TG (mmol/l) = -0.80 X initial VLDL TG concentration + 0.68 The drug affected the low density lipoprotein (LDL) cholesterol= -0.45 X initial LDL cholesterol + 61 This means that LDL cholesterol on average decreased if the initial LDL concentration was above 135 mg/100 ml and increased below that concentration. LDL TG and high density lipoprotein (HDL) TG concentrations also decreased significantly. A slight increase in HDL cholesterol concentration occurred after administration of gemfibrozil. Two subjects had to stop treatment because of nausea and abdominal pain respectively, attributed to the drug. No biochemical side effects were noted.

Cholesterol↗