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Biomedical subjects

A Gustafson

Publications and source records attributed to A Gustafson.

At least 73 records · Page 4Linked to original sources
PubMed1981

Effects induced by two different estrogens on serum individual phospholipids and serum lecithin fatty acid composition.

Eleven oophorectomized women (mean age 34.5 +/- 5.9) received two treatment cycles, one of the 17-C-alkylated ethinyl estradiol 20 microgram per day, and the second of the non-alkylated estrogen, estradiol valerate 2 mg per day for six weeks in separate periods preceded by six weeks without hormonal replacement therapy. Blood samples were drawn before and after six weeks on each estrogen. The samples were assayed for individual phospholipids i.e. cephalin, lecithin, lysolecithin and sphingomyelin after separation of these lipids by thin layer chromatography. The relative fatty acid composition of serum and high density lipoprotein lecithin and serum cholesterol ester was determined by gas liquid chromatography. Both estrogens reversed the symptoms of estrogen deficiency and had similar effects on serum individual phospholipids i.e. causing an increase in lecithin concomitant with a decrease in lysolecithin. It is suggested that this lecithin-lysolecithin shift could depend on an inhibition of the hepatic lipase and its phospholipase A1-activity. Both estrogens increased serum lecithin arachidonic acid without causing any change in linoleic acid (the major essential fatty acid), which indicates that this increase in arachidonic acid could be an estrogenic effect independent of dietary factors. Ethinyl estradiol caused an increase in palmitic and a decrease in stearic acid in the 1-position of serum lecithin while estradiol valerate did not influence these fatty acids at all. This palmitic-stearic acid shift induced by ethinyl estradiol is interpreted as a non-hormonal "drug-effect" linked to the liver toxicity of 17-C-alkylated steroids in spite of the lack of influence on routine liver function tests.

Adult↗
PubMed1981

The use of thallium-201 myocardial scintigraphy for the diagnosis of previous infarction.

The ability of thallium-201 scintigraphy to detect previous infarction (greater than 6 months ago) was studied in 43 patients with coronary artery disease, 39 with valvular heart disease, and 5 with cardiomyopathy or myocarditis. All patients had undergone selective coronary arteriography and left ventricular angiography. Thallium-201 scintigraphy at rest proved a very sensitive method for detecting previous infarction, also clinically silent. Scintigraphy was more sensitive than a recent ECG. However, scintigraphy can give falsely positive results.

Evaluation Studies as Topic↗
PubMed1981

Effect of inhibition of protein synthesis on thyroid cyclic AMP accumulation in vitro.

When thyroid cells in vitro are stimulated by TSH for 2 h cyclic AMP (cAMP) is synthesized at a high rate during the first 25 min of stimulation, thereafter at a lower rate. The mechanism for this reduction of adenyl cyclase activity was studied in vitro using mouse thyroid tissue. As some of the cAMP formed is released from the cells the sum of cAMP in tissue and incubation medium was studied and considered to reflect the accumulated cAMP synthesis as breakdown synthesis as breakdown by phosphodiesterase was minimized by 1 mM theophylline. The TSH stimulated tissue did not release any adenyl cyclase inhibiting factor into the incubation medium. Cycloheximide, 5 micrograms/ml, enhanced the cAMP response to a single or repeated stimulation by TSH. Its effect was visible after 25 min of incubation and remained at about the same size for 2 h, but the levelling off of cAMP synthesis was not prevented but took place at a higher level. The effect of puromycin, 500 microgram/ml, was similar to that of cycloheximide. Also actinomycin D, 1 microgram/ml, enhanced the cAMP response to TSH. It is concluded that a protein synthesis dependent inhibitor of adenyl cyclase is activated by TSH, but it accounts only for a minor part of the adenyl cyclase inhibition that takes place in the later part of a TSH stimulation of the thyroid. Additional adenyl cyclase inhibiting mechanisms must be considered.

Animals↗
PubMed1980

[Effects of fenofibrate in four types of hyperlipoproteinaemia and on apoproteins A and B in type IIa HLP (author's transl)].

Fenofibrate in doses of 300 mg/day was administered for 3 consecutive months to 31 patients with type IIa, IIb, III or IV hyperlipoproteinaemia (HLP). Mean plasma cholesterol levels decreased by 22% in type IIa (n = 15), by 19% in type IIb (n = 10), by 51% in type III (n = 2) and by 5% in type IV (n = 4) HLP. Mean plasma triglyceride levels were reduced by 32, 38, 60 and 52% respectively in these four types of HLP. Apo-A, measured in 11 patients with type IIa, HLP increased by up to 28% after three months' treatment, whereas alphalipoprotein cholesterol only slightly rose by a mean 11%. Apo-B decreased by 14%. Fenofibrate was well tolerated. Only one patient developed a pruriginous rash at the end of the treatment period.

Apolipoproteins↗
PubMed1980

Effects of jejuno-ileal bypass on serum lipoproteins and glucose tolerance in severely obese patients.

Plasma insulin and blood glucose during oral glucose tolerance tests (OGTT) and serial determinations of serum lipoprotein fractions before and after jejuno-ileostomy in twenty severely obese (mean weight 137 kg) patients with a mean age of 29 years revealed statistically significant postoperative decreases in all parameters concomitant with a mean weight loss of 42 kg. Before the operation the patients were hyperinsulinaemic and had elevated blood glucose levels during OGTT though no patient had overt diabetes. Serum triglyceride and total cholesterol levels were normal but HDL cholesterol was significantly lower than in controls. During follow-up at least until body weight had levelled off a mean 19 months post-operative, there were statistically significant reductions in blood glucose and plasma insulin as well as serum total cholesterol and lipoprotein fractions. There was no change in serum triglycerides. The low preoperative HDL levels decreased. In a subgroup of these patients we have earlier shown postoperative increases in arterial tissue cholesterol coincident with the present significant decreases in HDL as well as in LDL cholesterol. Correlations between total cholesterol and lipoprotein cholesterol values in serum and blood glucose and plasma insulin at fast and during OGTT and changes in these parameters demonstrate interrelationships between lipid and carbohydrate metabolism. The bypass procedure most likely reduces the intestinal synthesis of HDL which in turn may increase hepatic cholesterol synthesis. Evidently there is a multifactorial aetiology for the low HDL levels in the severely obese both before and after jejuno-ileostomy.

Adult↗
PubMed1980

Lipid metabolic studies in oophorectomized women: effects induced by two different estrogens on serum lipids and lipoproteins.

11 oophorectomized women (mean age 34.5 +/- 5.9) were given the 17-C-alkylated ethinyl estradiol (EE) 20 microgram/day and the non-alkylated estrogen, estradioil valerianate (E2V) 2 mg/day for 6 weeks in separate periods preceded by 6 weeks without hormonal replacement therapy. Blood samples were drawn before and after 6 weeks on each estrogen. Serum phospholipids, cholesterol and triglycerides were assessed. Preparative ultracentrifugation with the isolation of the very low density (VLDL; d < 1.006 g/ml); the low density (LDL; d = 1.006-1.063 g/ml) and the high density lipoprotein (HDL; d > 1.063 g/ml) fraction was carried out. In the three lipoprotein fractions, phospholipid, total cholesterol, free cholesterol and triglycerides were determined. An oral glucose tolerance test with concomitant plasma insulin determination was performed. In the present study EE caused an increase in serum total and LDL triglycerides while there was a reduction of triglycerides in serum as well as in VLDL and LDL when E2V ws administered. There was a positive correlation between plasma insulin values during oral glucose tolerance test and serum and VLDL triglycerides when E2V was administered. This finding supports earlier studies indicating that insulin (or rather the insulin-glucagon relationship) influences the hepatic triglyceride production rate. Both EE and E2V increased HDL cholesterol, but E2V did not induce a concomitant increase in serum triglycerides which would suggest a more physiological effect from the latter compound since fertile females have lower serum triglycerides and higher HDL cholesterol levels than males of corresponding age. The same differences are true in a comparison between fertile and post-menopausal women.

Adult↗
PubMed1980

Studies in normal pregnancy. III. Fatty acid composition of serum phosphoglycerides and cholesterol esters.

Metabolic and hormonal influences on liver lipid synthesis are reflected in the relative fatty acid composition of serum lecithin. Thus, a successive decrease in essential fatty acids (EFA), i.e. n-6 fatty acids, during pregnancy would indicate an incipient EFA deficiency at the time of delivery. Furthermore, reciprocal changes in linoleic and arachidonic acids during the 1st trimester with an increase in arachidonic acid would suggest an enhancement of the Greenbeg Pathway (Pathway II) in lecithin synthesis presumably caused by estrogen influence. During the 2nd and 3rd trimester, reciprocal changes in lecithin content of palmitic and stearic acids are similar to changes appearing under cholestasis. It is furthermore suggested that variations in the utilization of linoleic acid in cholesterol esters (expressed as cholesterol ester 18:2/lecithin 18:2) might reflect changes in plasma cholesterol esterification by the enzyme lecithin-cholesterol-acyl-transferase (LCAT). Then, in late pregnancy, in relation to a subclinical cholestatic liver engagement, LCAT activity would increase as judged from this ratio as well as the increased linoleic acid in cholesterol esters.

Adolescent↗
PubMed1980

Lipid and carbohydrate metabolism in uremia. Influence of treatment with protein-reduced diet and essential amino acids.

The effects of low protein diet on lipid and carbohydrate metabolism in uremia were investigated in 22 patients treated during a period of 3--18 months (mean 9.5 months). Before treatment, the patients showed elevated serum triglycerides, low alpha-lipoprotein cholesterol and reduced glucose elimination rate. There were no major changes in mean serum lipid or carbohydrate metabolism variables during treatment. The arachidonic acid content of lecithin decreased while linoleic acid increased during treatment. While the dietary treatment was effective in ameliorating uremic symptoms, it did evidently not influence the deranged lipid/carbohydrate metabolism.

Adolescent↗
PubMed1979

Lecithin : cholesterol acyl transfer (LACT) and fatty acid composition of lecithin and cholesterol esters in young male myocardial infarction survivors.

Lecithin : cholesterol acyl transfer (LCAT) and relative fatty acid composition of serum lecithin and cholesterol esters were studied in 20 young male survivors of myocardial infarction (MI). Comparisons were made with controls matched for serum cholesterol. There was no difference in LCAT rate between MI patients and controls. The relative content of arachidonic acid in cholesterol esters was higher in MI patients. The fatty acid composition of lecithin and cholesterol esters suggests an equal transfer of linoleic and oleic acids from lecithin to cholesterol. Furthermore negative correlations were found between LCAT and linoleic acid content of lecithin (r = --0.43, P less than 0.01) and cholesterol esters (r = --0.45, P less than 0.01). This inverse relationship does not seem to be linked to substrate specificity, but rather to be mediated by influences in common on serum lipid content and turnover.

Adult↗
PubMed1979

Lipid and carbohydrate metabolism in uraemia.

Lipid and carbohydrate metabolism variables were studied in twenty-eight patients with chronic renal failure (mean GFR 7.7 +/- 2.5 ml/min) and uraemic symptoms. 71% of the patients had hypertriglyceridaemia (greater than or equal to 2.2 mmol/l). Total serum cholesterol was normal while VLDL cholesterol was high and alpha-lipoprotein cholesterol was low. The fractional elimination rate of Intralipid was low and inversely correlated to serum triglyceride levels. Intravenous glucose tolerance was reduced with normal or slightly increased fasting blood glucose and insulin values before and during the test. Serum triglycerides were correlated to plasma insulin but not to residual renal function or serum urea levels. The cause of hypertriglyceridaemia and lowering of alpha-Lp cholesterol is not unequivocally clear. Present evidence indicate that retarded catabloism of triglyceride-rich lipoproteins is important but accentuated release of triglyceride-rich lipoproteins may have occurred in a number of cases. The commonly used treatment with beta-blocking agents for hypertension in chronic renal failure may accentuate certain of the metabolic responses in uraemia.

Adolescent↗
PubMed1979

Lipid metabolic studies in oophorectomized women. Effects of three different progestogens.

Ten oophorectomized women (ranging in age from 27 to 45 years, having a mean age of 34.5 years with a standard deviation of 5.3) were given three different progestogens (norgestrel, norethisterone and medroxyprogesterone) in treatment periods of 3 weeks' duration immediately preceded by 3 weeks "wash out" periods. Venous blood samples were drawn before and after each treatment period. Free and total cholesterol, triglycerides and phospholipids were determined in the three lipoprotein fractions: Very low density lipoproteins (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL). Individual phosphatides were determined after thin layer chromatography. In addition, the relative fatty acid composition of serum lecithin and cholesterol esters were assessed by gas-liquid-chromatography. Both norethisterone and norgestrel caused a decrease in alpha-lipoprotein cholesterol. The relative fatty acid composition of serum lecithin revealed an increase of biochemical pathway 1 for liver lecithin synthesis on norgestrel and norethisterone but no major changes on medroxyprogesterone. With norgestrel an increase in serum-lysolecithin concomitant with a decrease in lecithin was observed, while the two other progestogens did not induce any significant changes. From the present data it is suggested that the 19-norethisterone derivatives, norethisterone and especially norgestrel, have androgen-like influences on lipid metabolism. Medroxyprogesterone, being a 17-alpha-hydroxyprogesterone, caused less changes and consequently less disturbance of lipid metabolism.

Adult↗