PubMed Health⌕ Search

Biomedical subjects

P V Luoma

Publications and source records attributed to P V Luoma.

At least 19 recordsLinked to original sources
PubMed1997

Gene activation, apolipoprotein A-I/high density lipoprotein, atherosclerosis prevention and longevity.

Recent studies in man and human apolipoprotein A-I transgenic animals emphasize the significance of apolipoprotein A-I and high density lipoprotein in antiatherogenesis. Several drugs and other compounds, e.g. phenobarbital, gemfibrozil, fenofibrate, prednisone, estrogen and alcohol, induce apolipoprotein A-I synthesis. They commonly produce serum lipoprotein patterns typical of a low risk of coronary heart disease, and many of them have been found to prevent atherogenesis, reduce coronary heart disease mortality and increase survival. These compounds act against atherosclerosis by using one or several mechanisms that include overexpression of the apolipoprotein A-I gene with an increase in serum apolipoprotein A-I and high density lipoprotein and promotion of reverse cholesterol transport, upregulation of the low density lipoprotein receptor gene with a decrease in serum apolipoprotein B and low density lipoprotein, maintenance of endothelial cell function and protection against thrombosis. They have been found to raise high density lipoprotein cholesterol and apolipoprotein A-I together with a decrease in cholesterol ester transfer protein activity, and to induce hepatic cholesterol 7 alpha-hydroxylase and cholesterol and bile acid elimination from the body. By raising the activities of apolipoprotein A-I/high density lipoprotein-associated paraoxonase and other antioxidative enzymes, the inducers have the capacity to prevent atherogenesis in arterial walls through inhibition of the oxidative modification of low density lipoprotein. Other antiatherogenic vascular actions of high density lipoprotein include interference with low density lipoprotein aggregation and uptake by endothelial cells, and competition with low density lipoprotein for endothelial-localized low density lipoprotein receptors. Apolipoprotein A-I/high density lipoprotein beneficially enhances fibrinolysis, decreases platelet aggregation, increases prostacyclin production and stabilization and prevents atherogenic immune and inflammatory responses. This gene activation or microsomal induction can prevent atherosclerosis and is a basis for tailoring effective new agents and optimal non-invasive therapy against atherosclerotic vascular disease to promote health and enhance longevity.

Animals↗
PubMed1995

Association of blood cadmium to the area of residence and hypertensive disease in Arctic Finland.

The association of cadmium exposure with area of residence, blood pressure, and arterial hypertensive disease was examined in 230 reindeer herders in northernmost arctic Finland. Blood cadmium concentration averaged 10.0 nmol/l, and was three times higher in smokers than in nonsmokers (16.7 vs. 5.5 nmol/l). Concentrations increased from the southwestern to the northeastern area west of the Kola Peninsula, Russia, both in nonsmokers (3.1 vs. 6.8 nmol/l) and smokers (10.8 vs. 32.0 nmol/l). High cadmium levels were most common in the northeast: 32% of the values were at least 15 nmol/l, 10% at least 45 nmol/l (health-based limit of WHO), and 3% at least 90 nmol/l (the critical limit for renal damage). High cadmium concentration was associated with a rise in blood pressure; the rise was particularly pronounced in subjects with hypertensive diseases. These associations were not affected by age, body mass index, smoking, and alcohol consumption. The results suggest that cadmium exposure may have harmful health effects in arctic Finland and emphasize the importance of reducing pollution from industrial sources in the Kola Peninsula.

Adult↗
PubMed1995

High serum alpha-tocopherol, albumin, selenium and cholesterol, and low mortality from coronary heart disease in northern Finland.

OBJECTIVES: The mortality from coronary heart disease (CHD) is exceptionally low in northernmost Finland, the Sámi (formerly known as Lapp) area. To clarify the reasons for this, the levels of serum cholesterol, other classic risk factors, and major antioxidants, alpha-tocopherol, retinol, albumin and selenium were determined in males living in the low-mortality area and in a reference area. DESIGN: A health survey amongst reindeer herdsmen living in the three northernmost communes of Finland (the Sámi area) and in the six neighbouring communities to the south (the reference area). The mortality from CHD in the two areas was determined from death certificates issued during the period 1981-1990. SUBJECTS: A total of 350 participants of the health survey, mean age 46 (SD 14) years. RESULTS: The mortality from CHD was 17% lower in the Sámi area than in the reference area [95% confidence interval (CI) for the difference: 4-29]. Subjects living in the low-mortality area showed higher serum-lipid-adjusted alpha-tocopherol (18.4 vs. 16.1 mumol L-1; 95% CI for difference: 0.7-3.9; P < 0.001), albumin (46.9 vs. 46.2 g L-1; 0.2-1.3; P < 0.02), selenium (1.59 vs. 1.47 mumol L-1; 0.02-0.22; P < 0.02), cholesterol (6.76 vs. 6.34 mmol L-1; 0.12-0.72; P < 0.001) and LDL cholesterol (4.76 vs. 4.45 mmol L-1; 0.05-0.57; P < 0.02) than those in the reference area. The HDL cholesterol:cholesterol ratio was lower in the Sámi area than in the reference area (0.20 vs. 0.21; -0.02-0.00; P < 0.04). The Sámis showed higher serum selenium than the Finns. Serum alpha-tocopherol increased with the consumption of reindeer meat and serum selenium increased with fish consumption. CONCLUSIONS: Alpha-tocopherol, albumin and selenium may play a role in the low mortality from CHD observed in northernmost Finland. The favourable serum antioxidant status in northerners may be credited to the local diet.

Adult↗
PubMed1992

Blood mercury and serum selenium concentrations in reindeer herders in the arctic area of northern Finland.

163 healthy reindeer herders living in the arctic area of northern Finland were investigated for blood mercury and serum selenium concentrations. More than ten percent of the subjects had blood mercury above the upper normal limit. High organic and total organic mercury levels were most common in the northeastern part of the country. High organic and total mercury and selenium values were more common in the Lapps than the Finns. Blood mercury levels increased with increasing fish consumption. The pollution in the northeastern part of this country probably leads to the increased formation of organic mercury, and its enrichment in the food chain. The association of high selenium with high mercury probably reduces the toxicity of the latter.

Analysis of Variance↗
PubMed1990

High-density lipoprotein subfractions, apolipoproteins and antipyrine clearance in normal subjects.

Serum high density lipoprotein (HDL) subfractions HDL2 and HDL3, apolipoproteins, and plasma antipyrine clearance (AP-CL) rate, an index of liver microsomal enzyme activity, were determined in 21 healthy subjects. High HDL cholesterol and HDL2 cholesterol concentrations and HDL cholesterol/cholesterol and HDL2/HDL3 cholesterol ratios were associated with high AP-CL. Phenobarbital enhanced antipyrine elimination and increased the apolipoprotein A-I/A-II ratio. Subjects who had high AP-CL had a more antiatherogenic HDL subfraction and apolipoprotein profile than those with low AP-CL.

Adult↗
PubMed1990

Lipid peroxides, glutathione peroxidase, high density lipoprotein subfractions and apolipoproteins in young adults.

Lipid peroxides have been implicated in the initiation of atherogenesis. In this study of 23 young healthy subjects, high levels of serum lipid peroxides were associated with low serum HDL2 cholesterol concentrations and low HDL2/HDL3 cholesterol and apolipoprotein A-I/A-II ratios. Low levels of LDL cholesterol and apolipoprotein B, and low apolipoprotein B/A-I ratios were typical of subjects with high serum glutathione peroxidase activities. Serum lipid peroxide levels varied widely in subjects without abnormal cholesterol, HDL cholesterol or LDL cholesterol concentrations. This variation may play a role in the frequent occurrence of coronary artery disease in normolipidaemic individuals.

Adult↗
PubMed1988

Microsomal enzyme induction, lipoproteins and atherosclerosis.

The liver is the principal site for the synthesis and elimination of lipoproteins circulating in plasma, and alterations in hepatic function influence plasma lipoprotein levels. High HDL-C/T-C and apo A-I/apo B ratios, which are characteristic of a low coronary risk, have been typical of healthy subjects with high microsomal enzyme activity in the liver. Microsomal enzyme inducing drugs such as phenytoin, phenobarbital and carbamazepine, and also alcohol, influence serum lipid and apoprotein concentrations. The inducers increase the concentrations of hepatic microsomal enzyme and apo A-I mRNA, and also proteins and phospholipids. They similarly increase serum HDL-C and apo A-I levels and the HDL-C/LDL-C ratio, powerful protective factors against coronary heart disease. These parameters parallel hepatic protein and phospholipid concentrations, and microsomal enzyme activity as assessed by liver cytochrome P-450 or antipyrine kinetics. Serum LDL-C levels are inversely proportional to hepatic cytochrome P-450 concentrations. Experimental studies indicate that phenobarbital retards cholesterol accumulation in the arterial wall and the formation of atherosclerotic plaque. A decreased mortality rate from coronary heart disease has been reported for subjects who take enzyme inducers, drugs or alcohol, whereas impairment of hepatic microsomal function may promote atherogenesis. In addition to drugs non-pharmacological factors such as dietary constituents and physical exercise may influence hepatic microsomal function and hence improve the serum lipoprotein profile. These observations, which connect microsomal inducers, liver lipids and proteins, serum lipids and apoproteins characteristic of a low risk of atherosclerotic disease and low incidence of coronary deaths, lead to the conclusion that the activation of liver microsomal function can prevent atherogenesis in man.

Arteriosclerosis↗
PubMed1988

The effects of phenobarbital on serum high density lipoprotein subfractions and apolipoproteins.

Prospective studies report that a pharmacologic elevation of serum high density lipoprotein (HDL) concentration may be of value in the prevention of atherosclerosis. In this study phenobarbital, 50 mg at bedtime for ten days, increased serum HDL cholesterol, HDL2 cholesterol and HDL cholesterol/cholesterol and HDL cholesterol/apolipoprotein A-I ratios. Phenobarbital treated subjects had serum lipoprotein profile typical of low risk of ischemic heart disease.

Adult↗
PubMed1987

One year study of effects of an oestrogen-dominant oral contraceptive on serum high-density lipoprotein cholesterol, apolipoproteins A-I and A-II and hepatic microsomal function.

The effects over 1 year of an oestrogen-dominant oral contraceptive containing ethinylestradiol and levonorgestrel on serum high-density lipoprotein cholesterol, apolipoproteins A-I and A-II and liver microsomal enzyme activity assessed by antipyrine kinetics, were investigated in 21 healthy, young women. HDL cholesterol and apolipoprotein concentrations rose and hepatic microsomal enzyme activity fell during the first month of the treatment, and remained affected throughout the year. After discontinuation of treatment, the lipid and apolipoprotein concentrations and the microsomal enzyme activity returned to their pretreatment levels within 1 month. The drug, by reducing hepatic enzyme activity, may have influenced both the antipyrine elimination rate and the high-density lipoprotein concentration.

Adult↗
PubMed1985

Relationship between lipid composition and drug metabolizing capacity of human liver.

The relationship between hepatic glycerolipids and microsomal drug-metabolizing enzymes was studied in liver biopsies from 41 subjects. The series included obese, diabetic, epileptic and chronic alcoholic patients, all of whom were hospitalized for suspected hepatic ailments (fatty liver, hepatitis or cirrhosis). Therapy with enzyme-inducing anticonvulsants was associated with high phospholipid and cytochrome P-450 and low triacylglycerol concentration in the liver. In patients with fatty liver or cirrhosis low phospholipid and cytochrome P-450 and high triacylglycerol concentrations were observed. There was a significant correlation (r (Pearson's product moment correlation coefficient) = 0.91) between the hepatic phospholipid and cytochrome P-450 concentration. The cytochrome P-450 concentration was inversely related (r = -0.74) to the triacylglycerol concentration. The positive correlation between hepatic phospholipids and drug-metabolizing enzymes could be interpreted as indicating that in human liver phospholipid and cytochrome P-450 synthesis share common regulators, or that phospholipids are necessary for the maximum rate of cytochrome P-450 synthesis.

Adult↗
PubMed1985

Serum low-density lipoprotein and high-density lipoprotein cholesterol, and liver size in subjects on drugs inducing hepatic microsomal enzymes.

Serum low-density lipoprotein cholesterol and high-density lipoprotein cholesterol concentration and the ratio between them, major risk factors of coronary heart disease, and liver size were investigated in 18 subjects who were on enzyme-inducing anticonvulsants, phenytoin alone or in combination with phenobarbital and/or carbamazepine. The subjects with a high liver cytochrome P-450, indicating hepatic microsomal enzyme induction, who showed an increase in liver size, had an elevated high-density lipoprotein concentration and high-density lipoprotein cholesterol/total cholesterol ratio, and a reduced low/high-density lipoprotein cholesterol ratio. The high-density lipoprotein cholesterol concentration and its ratio to total cholesterol were directly and related to the ratio between low and high-density lipoprotein cholesterol were inversely related to the extent of liver enlargement. The serum cholesterol distribution profile associated with an increase in liver size was typical of subjects with a low risk of coronary heart disease. The results suggest that enzyme-inducers, such as phenytoin and phenobarbital, induce structural and functional changes in hepatocellular membranes associated with liver enlargement and cholesterol distribution characteristic of low susceptibility to atherosclerotic vascular disease.

Adult↗
PubMed1985

Decreased serum selenium in alcoholics as related to liver structure and function.

Serum selenium was evaluated in relation to hepatic structure and function in 46 alcoholics with diagnostic liver biopsy classified into 4 groups by hepatic histology. Their serum selenium concentration varied from 12 to 88 micrograms/l and was lower (p less than 0.001) in all groups of alcoholics, ie patients with normal liver (53.0 +/- 20.7 micrograms/l, mean +/- SD), fatty liver (55.8 +/- 21.2 micrograms/l), alcoholic hepatitis (46.0 +/- 14.1 micrograms/l), and cirrhosis (41.1 +/- 12.8 micrograms/l), than in 25 healthy controls (88.7 +/- 11.0 micrograms/l). Serum selenium level was related to the severity of liver disease, and most reduced in subjects with decompensated alcoholic cirrhosis. Their serum selenium level (29.2 +/- 13.7 micrograms/l) was below (p less than 0.05) that obtained in alcoholics with normal liver and fatty liver respectively. Both inadequate dietary selenium intake and alcohol-induced changes in hepatic structure and function may have contributed to the decrease of serum selenium in the subjects studied.

Adult↗
PubMed1985

Plasma HDL cholesterol and blood glucose in non-insulin-dependent diabetics related to liver lipids and microsomal enzyme activity.

The major lipid predictors of coronary events, plasma high density lipoprotein cholesterol (HDL-C) and the HDL-C/total cholesterol (T-C) ratio, and blood glucose (BG) in 12 subjects with non-insulin-dependent diabetes mellitus were related to hepatic lipids, proteins and microsomal enzyme activity assessed by liver cytochrome P-450 (P-450). Non-insulin-dependent diabetics had low HDL-C/T-C ratio, liver phospholipid (PL) and P-450 and high serum and liver triglyceride (TG) concentrations. Plasma HDL-C was decreased, and BG high, especially in subjects with reduced PL and P-450. The HDL-C/T-C ratio was directly proportional to liver PL and P-450 and unrelated to hepatic TG. Increases in liver PL and microsomal enzyme activity may be favorably reflected both in cholesterol distribution and diabetic control.

Blood Glucose↗
PubMed1985

Combined oral and home parenteral nutrition for the short bowel syndrome.

Combined parenteral and peroral nutrition is necessary when a large small bowel resection leads to inadequate intestinal absorption and starvation. We report the case of a 17-year old schoolgirl in whom, following a rupture of the spleen and splenectomy, extensive small bowel necrosis necessitated small bowel resection from the lig. Treitz to the terminal ileum saving the last ten centimeters of the ileum. The serious starvation which developed after the operation was first treated with a one-month course of parenteral nutrition in hospital. Thereafter the patient took care of the infusions herself. Home parenteral nutrition took place during a 10-12 h overnight period 5 times a week. The proportion of peroral dietary intake was increased gradually during the first year, after which a 1 to 1 ratio between peroral and parenteral intake of energy and protein was maintained. The patient's subjective and objective well-being after two-years' of follow-up is good. Regular examinations at 3-6 month intervals are needed for the maintenance of adequate nutritional replacement.

Adolescent↗
PubMed1984

Drug metabolism in diabetic subjects with fatty livers.

The effect of fatty degeneration of liver parenchyma on drug metabolism was investigated in 21 obese non-insulin-dependent diabetic subjects by measuring plasma antipyrine kinetics, hepatic cytochrome P-450, liver size and the extent of fatty infiltration. The hepatic drug metabolising capacity, as measured by total antipyrine clearance and the estimated total amount of cytochrome P-450, was at the same level as in non-diabetic control subjects with normal livers. Relative antipyrine clearance (per unit weight of liver) and cytochrome P-450 concentrations were significantly lower in the diabetics than in controls. The extent of fatty infiltration correlated poorly with the indices of drug metabolism. In non-insulin-dependent diabetics, slight to moderate hepatic fatty infiltration, without more serious structural distortion interfering with hepatic blood flow or hepatocellular function, seems to have only a minor influence on drug metabolism.

Adult↗
PubMed1984

The effect of phenobarbital on serum hormone levels and their diurnal variations in pregnancy.

The effect of phenobarbital (PB) on serum hormones in late pregnancy was investigated. 18 pregnant women were studied before and after 2 weeks of PB treatment (100 mg per os, daily at 8 p.m.) by measuring serum estradiol, estriol, progesterone, testosterone, prolactin and cortisol concentrations. 7 pregnant women without PB therapy served as controls. Estradiol levels in the morning decreased, whereas those of estriol increased both in the morning and evening during PB treatment. The estriol/estradiol ratio increased in women on PB. PB affected the diurnal variation of hormones; the decrease in estradiol concentration between 8 a.m. and 8 p.m. was eliminated and the decrease in estriol concentration became more clear. PB did not significantly affect the serum levels of the other hormones investigated. As an enzyme-inducer PB may affect the fate of sex hormones.

Adolescent↗
PubMed1984

Serum selenium, glutathione peroxidase activity and high-density lipoprotein cholesterol--effect of selenium supplementation.

In a prospective study a low serum selenium level was associated with an increased risk of coronary death and myocardial infarction (1). This study examined the relationship of serum selenium concentration with serum glutathione peroxidase activity (GSH-Px) and lipids connected with coronary atherogenesis. Serum selenium levels in 26 healthy subjects were positively correlated with GSH-Px activities and high-density lipoprotein cholesterol concentrations. Selenium supplementation increased serum selenium level and the GSH-Px activity in a double-blind evaluation. The high-density lipoprotein cholesterol/cholesterol ratio increased during selenium supplementation in a group excluding subjects with a low cholesterol. The results suggest a link running from low serum selenium to reduced high-density lipoprotein cholesterol, and further to high coronary risk. Selenium supplementation may in subjects with low selenium reduce the the risk of coronary heart disease.

Adult↗