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Biomedical subjects

T Nikkari

Publications and source records attributed to T Nikkari.

At least 91 records · Page 5Linked to original sources
PubMed1986

Comparison of different ways of presenting the results of biochemical analyses of human coronary arteries.

Three methods of expressing the results of biochemical analyses of normal and atherosclerotic human coronary intima-medias were compared by calculating the results per unit area of vessel surface to obtain the content, per unit weight of dry defatted tissue (d.t.) to obtain the concentration, and per unit weight of organic d.t. to obtain the inorganic salt-corrected concentration. The content reflects the amount of a substance in an anatomically defined portion of the arterial wall, whereas the concentration gives the amount of the substance relative to a defined mass of arterial tissue. Since calcium salts form a sizable portion of fibrous plaques, concentrations become overcorrected in the oldest age groups. For example, there was an unexpected age-related decrease of collagen concentration in fibrous plaques-containing coronary arteries while its content and inorganic salt-corrected concentration increased. In studies involving arterial biochemical analyses it is appropriate to calculate the results in terms of both the content and the concentration. If severely affected specimens are studied, it is recommendable also to use the inorganic salt-corrected concentration, especially when different age groups are compared with one another.

Adolescent↗
PubMed1986

Serum fatty acids and coronary heart disease in Finnish populations.

Finland has one of the highest coronary heart disease (CHD) rates in the whole world, and within the country, the rates are higher in men and eastern Finland than in women and western Finland, respectively. The differences are not wholly explained by the 3 classical risk factors. Several cross-sectional and longitudinal studies suggest that the intake of dietary linoleate (18:2), as reflected in the composition of serum and tissue fatty acids, has an inverse association with CHD, although there are also studies with negative results. Our own retrospective study failed to show any differences in the fatty acid composition of serum CE, TG or PL between men who had died of CHD and age- and risk factor-matched controls, but the negative finding may be due to changes in the fatty acids during storage. Among Finnish populations, most serum CE fatty acids had highly significant correlations with those in other serum lipid fractions, adipose tissue and platelets, and they had good "tracking" for up to 4 yr. Serum CE and TG 18:2, and total omega 6 polyunsaturated fatty acids (PUFA) had strong correlations with dietary 18:2 and PUFA, and can thus be used in the evaluation of population differences in the intake of PUFA. CE fatty acids were analyzed in a total of 2820 free-living 1- to 85-yr-old males and females. The percentages of serum fatty acids were age-dependent. West-Finnish populations had higher contents of 18:2 than those in eastern Finland, and middle-aged women had higher proportions of 18:2 than men. The content of 18:2 in adipose tissue and/or serum CE of middle-aged men was comparable to that in Scotland and lower than those in Italy and Sweden. These findings are compatible with the idea that 18:2 is a negative risk factor of CHD, but the evidence is only circumstantial. Possible mechanisms whereby 18:2 could affect CHD have been discussed. The contents of omega 3 fatty acids in CE were opposite to those of omega 6 fatty acids in that eastern Finnish and male populations had higher contents of 18:3 omega 3 and 20:5 omega 3 than western Finns and females, respectively. This finding is apparently due to substitution of vegetable fat for milk fat in the diet, resulting in a relative deficiency of the omega 3 fatty acids at the expense of 18:2. Experimental evidence for such a mechanism was obtained in an intervention study.(ABSTRACT TRUNCATED AT 400 WORDS)

Coronary Disease↗
PubMed1986

Glycosaminoglycans in normal and atherosclerotic human coronary arteries.

Glycosaminoglycans (GAGs) were studied in normal and atherosclerotic coronary arteries of 15- to 60-year-old Finnish men who had died accidentally. The GAGs were fractionated and quantified with electrophoretic techniques. The contents of sulfated GAGs (micrograms/cm2 vessel surface area) increased continuously until 20 to 30% of the vessel surface area was covered with fibrous plaques, after which they started to decrease. The largest increases were seen in chondroitin sulfates A and C and dermatan sulfate, the former of which rose earlier with lesion development. In normal coronary arteries the contents of dermatan sulfate and chondroitin sulfates A and C increased significantly with age, but the rises were much smaller than those found in affected vessels. The age-related changes in the percentage composition of GAGs in normal coronaries were qualitatively similar to those found in affected coronaries during lesion development. The alterations in arterial GAGs, therefore, seem to be related to two processes, both of which involve increased formation of connective tissue components by arterial smooth muscle cells: the normal growth and maturation of the vessels with a slow development of diffuse intimal thickening, and atherogenesis, which greatly increases the contents of sulfated GAGs in affected arteries.

Adolescent↗
PubMed1986

Stability of plasma fatty acids at -20 degrees C and its relationship to antioxidants.

The fatty acid composition of cholesteryl esters (CE), triglycerides (TG) and phospholipids (PL) was analysed with gas chromatography before and after 3 years' storage of EDTA plasmas at -20 degrees C. In the three lipid fractions the proportion of polyunsaturated fatty acids (PUFA) with 3 or more double bonds decreased by 14% to 46%, while the proportions of saturated and monounsaturated fatty acids and also of linoleate (18:2 omega 6) showed an increasing trend. The changes tended to be relatively greatest in TG and smallest in PL. The initial concentration of vitamin A correlated negatively with reductions of all 20- to 22-carbon PUFA in CE and with that of arachidonate (20:4 omega 6) and docosahexaenoate (22:6 omega 3) in TG. The change in CE-18:2 omega 6 tended to be inversely correlated with vitamin A. The initial concentration of beta-carotene and the change in CE- and TG-18:3 omega 3 and CE-22:6 omega 3 showed also inverse correlations. Vitamin C, alpha-tocopherol and selenium had only occasional and mostly insignificant associations with the fatty acid alterations. In freshly analysed samples the concentration of vitamin A correlated negatively with the percentage of 18:2 omega 6 in plasma CE, TG and PL and with that of 20:4 omega 6 in platelets, and beta-carotene and alpha-tocopherol had positive correlations with 18:2 omega 6 in most plasma lipid fractions and platelets. Vitamin C and selenium correlated positively with 22:6 omega 3 in plasma, and selenium also with that in platelets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Platelet aggregation in Finnish men and its relation to fatty acids in platelets, plasma and adipose tissue.

Platelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate. There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 omega 3-fatty acids in platelets (r = -0.26- -0.40) and with the platelet 20: 5 omega 3/20: 4 omega 6 and omega 3/omega 6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5 omega 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the omega 6-fatty acids. Thrombin-induced aggregation correlated negatively with the omega 3/6 omega ratio in adipose tissue (r = -0.25) and the 20: 3 omega 6/20: 4 omega 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4 omega 6 (r = 0.22) in plasma phospholipids (PL). The percentages of prostanoid precursors in platelet lipids, i.e. 20:3 omega 6, 20:4 omega 6 and 20:5 omega 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20:5 omega 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Diphosphate↗
PubMed1985

Effect of post-mortem time on the biochemical composition of coronary arteries.

The effects of post-mortem autolysis on the biochemical composition of coronary intima-medias were studied by keeping the coronary arteries of 25 slaughterhouse pigs at +4 degrees C for periods up to 7 days. The samples were analysed for DNA, total protein, collagen, glycosaminoglycans (GAGs), free and esterified cholesterol, triglycerides, phospholipid fractions, and fatty acid composition in various lipid classes. The content of sulphated GAGs decreased steadily, whereas that of hyaluronic acid remained unchanged. These alterations led to a significant decrease in the content of total GAGs and to an increase in the percentage of hyaluronic acid in total GAGs. The results indicate a continuous post-mortem degradation of arterial proteoglycans. After 7 days storage, there was a significant increase in the content of free fatty acids, and the composition of this fraction was changed by increases in the relative amounts of oleic and linoleic acids. These changes were accompanied by an increase in lysolecithin and a decrease in lecithin, which suggests a post-mortem action of arterial phospholipases.

Animals↗
PubMed1985

Fatty acid composition of serum cholesteryl esters in 3- to 18-year-old Finnish children and its relation to diet.

The composition of fatty acids in serum cholesteryl esters (CE) was analyzed gas chromatographically in 1348 boys and girls aged from 3 to 18 yr. A dietary survey was carried out simultaneously using the 48-h recall method. The dietary P/S ratio had highly significant correlations with CE fatty acids: positive with linoleate (0.567) and total omega 6 fatty acids and negative with saturated, monounsaturated, and omega 3 polyunsaturated fatty acids. The highest mean percentage of CE-linoleate was found in 15-yr-old girls (52.7, SD 4.68%) and lowest in 3-yr-old girls (48.1, SD 5.00%). Age, sex, and the degree of puberty had no independent effect on CE-linoleate after it had been adjusted for the effect of dietary P/S ratio by analysis of covariance. These results indicate that the fatty acid composition of serum CE depends on the quality of dietary fat and that CE-linoleate is a useful reflector of the dietary P/S ratio. The negative correlation between CE omega 3 fatty acids and dietary P/S ratio may be due to displacement of the omega 3 acids in serum CE by the much higher proportion of dietary linoleate.

Adolescent↗
PubMed1985

Neonatal jaundice and fatty acid composition of the maternal diet.

The role of serum fatty acid composition in neonatal jaundice was studied by comparing the incidence of jaundice among 332 newborn infants receiving breast milk from mothers on a diet with either a low (0.1, n = 145) or a high (1.5, n = 187) polyunsaturated to saturated fatty acid (P/S) ratio. The diet was started immediately after delivery. The composition of fatty acids in the breast milk and sera of the mothers and in the sera of the newborns was evaluated from a random sample of 15 mother-newborn pairs on the control diet (low P/S ratio) and 19 pairs on the experimental diet. Five days after delivery the relative amounts of fatty acids, especially that of linoleate, in the sera of the mothers differed significantly depending on the diet. Differences were also observed in breast milk samples taken three, four or five days after delivery and in the sera of the newborns sampled at the age of four or five days. Nine of the 145 newborn infants (6.2%) in the control group had to be treated with light therapy compared with 12 out of 187 (6.4%) of the newborn infants in the experimental group (high P/S ratio). Serum bilirubin concentrations were 142.5 mumol/l (SD 65.8) and 140.7 mumol/l (SD 73.5) in the experimental and control groups, respectively, at the age of five days. It appears that the changes in the composition of serum fatty acids reached in this study had no effect on the neonatal jaundice.

Bilirubin↗
PubMed1985

Atherosclerosis precursors in Finnish children and adolescents. IV. Serum lipids in newborns, children and adolescents.

A multicentre study on atherosclerosis precursors in Finnish children and adolescents was carried out in five urban and 12 rural areas in the autumn of 1980 and spring of 1981. Serum lipids, i.e. cholesterol (TC), HDL-cholesterol (HDL-C) and triglyceride (TG) concentrations were determined and LDL-cholesterol (LDL-C) was calculated in 630 newborns and 3,596 children aged 3, 6, 9, 12, 15 and 18 years. In the newborns the mean serum TC concentration was 1.50 mmol/l, and the ratio of HDL-C to TC was 0.44. Newborn boys had lower mean TC, HDL-C and LDL-C values than the girls. In 3 to 18-year-old children the mean TC, LDL-C and HDL-C concentrations were 4.83 mmol/l, 3.09 mmol/l and 1.38 mmol/l, respectively. During puberty, TC mean values decreased, more so in boys. The serum levels of HDL-C also decreased, especially in boys, and after passing puberty boys had lower mean HDL-C levels than girls (1.26 vs. 1.39 mmol/l, p less than 0.001). The HDL-C/TC ratio was similar in all age groups (0.29). The mean TG value increased with age, being 0.88 mmol/l at the age of 18 yr. During sexual maturation, TG levels increased, more clearly in boys. There were no regional differences in serum lipid concentrations in the newborns, but in 3- to 18-year-old children the mean TC, LDL-C and TG values were lower in western than in eastern Finland. Mean TC and LDL-C values were lower in urban than in rural areas, but there was no difference in TG concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Atherosclerosis precursors in Finnish children and adolescents. V. Fatty acid composition of serum cholesteryl esters: regional differences in Finland.

Fatty acid compositions of serum cholesteryl esters (CE) were analysed with gas chromatography from a total of 1,348 Finnish children. The study was a part of a comprehensive survey of atherosclerosis precursors among children, and included 3-, 6-, 9-, 12-, 15-, and 18-year-old children and adolescents from five urban and twelve rural communities in Finland. In all age groups and both sexes, the mean percentages of linoleate (CE-18:2) were lower and those of saturated and monounsaturated fatty acids higher in eastern rural areas than elsewhere. Eastern rural children also had significantly higher proportions of omega 3 polyunsaturated fatty acids in their serum CE's. The percentage of serum CE-18:2 parallels the P/S values obtained by a dietary survey from the same populations. The reason for higher percentages of the omega 3 fatty acids in rural communities cannot be explained by diet, and remains unclear.

Adolescent↗
PubMed1985

Atherosclerosis precursors in Finnish children and adolescents. VI. Serum apolipoproteins A-I and B.

The concentrations of apolipoproteins A-I and B were determined in 1,341 3- to 18-year-old children and adolescents from five urban and 12 rural communities. The analyses were made with radial immunodiffusion. The mean concentrations (+/- S.D.) of apo A-I and apo B were 152 +/- 25 and 94 +/- 22 mg/100 ml, respectively. 3-year-old children had the highest apo B levels which then decreased with advancing age in both sexes. Boys tended to have lower levels of apo B than girls. Apo A-I concentration was significantly higher in the 9- and 12-year-old boys than in the other age groups but showed no age-bound trend in girls. The apo A-I to apo B ratio increased with age in both sexes. The concentration of apo A-I was significantly lower, and that of apo B higher, in children living in eastern Finland in comparison with those from the western part of the country. This difference and a higher HDL-cholesterol to apo A-I ratio in both sexes in eastern Finland may be associated with the regional differences in the prevalence of coronary heart disease in this country.

Adolescent↗
PubMed1985

Coronary intimal thickenings and lipids in Finnish children who died violently.

Intimal thickenings of the coronary arteries were found in healthy children who died violently, of both sexes even in children under 5 years of age. The average incidence was 53 % of the 75 cases. Splitting of the internal elastic lamina was the primary finding, followed by local increase in smooth muscle cells. The thickening could occupy 50 % of the coronary lumen. The accumulation of esterified cholesterol in the coronary arteries began before the age of 10 years. The fatty acid composition of the cholesterol esters suggests that they are derived from the blood. The question whether the thickenings are precursors of forthcoming coronary atheromas needs further detailed studies, especially in young adults.

Adolescent↗
PubMed1985

Linoleic acid treatment in inflammatory arthritis.

Ten patients with chronic rheumatic diseases were treated either with sunflower oil (linoleic acid 66%; n = 6) or with olive oil (linoleic acid 4%; n = 4) for 21 days. Sunflower oil but not olive oil increased the serum concentrations of linoleic acid in all fractions studied. In cholesteryl esters, both arachidonic acid and dihomo-gamma-linolenic acid concentrations were slightly diminished. The changes in all these fatty acids were already seen on the first days of treatment. Plasma arachidonic acid metabolites showed no uniform changes during the treatment. Excretions of the main metabolite of prostacyclin (6-keto-PGF1 alpha) and thromboxane B2 into urine were slightly increased in most patients on sunflower oil. No marked improvement was seen in the clinical or conventional laboratory parameters in either treatment.

Arachidonic Acids↗
PubMed1985

Concentration and composition of serum lipoproteins during a low-fat diet at two levels of polyunsaturated fat.

A 12-week dietary intervention was carried out among 40 families from North Karelia, a county in Finland with an exceptionally high rate of coronary heart disease and high serum cholesterol values. The proportion of dietary energy derived from fat was reduced during the 12-week intervention period from about 39% to 23% in all families. The families were randomly allocated into two groups. Twenty families consumed a diet with a polyunsaturated to saturated fat (P/S) ratio of 0.9 (group I), while the other 20 families had a diet with a P/S ratio of 0.4 (group II). Total serum cholesterol decreased by 16% and 9% in men of groups I and II, respectively, and by 16% in women of both groups. These changes were due to a decrease in both low density lipoprotein (LDL) and high density lipoprotein (HDL) cholesterol. LDL cholesterol and phospholipid reached minimum values after 6 weeks on both intervention diets, but LDL protein responded more slowly. Thus, after 6 weeks LDL had an altered composition containing less cholesterol and phospholipids and more protein and triglycerides than during the baseline diet. During the intervention, the linoleic acid content in the serum cholesteryl ester fraction increased, and the magnitude of this change correlated negatively with the changes in total and LDL cholesterol. The decrease in HDL cholesterol during the two intervention diets was due to a fall in the HDL2 cholesterol (29% and 24% in men, and 26% and 25% in women in groups I and II, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Growth properties and composition of cytoskeletal and cytocontractile proteins in aortic cells isolated and cultured from normal and atherosclerotic rabbits.

Aortic intima-medias of normal and cholesterol-fed rabbits were studied with EM and cells were isolated by enzyme digestion. The composition of cytoskeletal and cytocontractile proteins was determined with SDS-PAGE and the primary growth and thymidine incorporation rates were assessed after seeding the cells into tissue culture flasks. Ultrastructurally, the SMCs in the thickened atherosclerotic intima differed from the contractile medial SMCs in containing lipid vacuoles, enlarged endoplasmic reticulum and a reduced number of myofilaments, thus showing characteristics of dedifferentiated SMCs. In SDS-PAGE, freshly isolated cells from the atherosclerotic intima-medias had a lower content of myosin and actin, and a higher proportion of vimentin and desmin than SMCs from normal aortas. Enzyme-isolated SMCs from normal aortas did not start to grow and incorporate radioactive thymidine until 5-6 days after seeding, whereas those from atherosclerotic aortas did so within 2 days. After a week in culture, SMCs from both sources resembled each other, and had decreased contents of myosin and actin, and increased concentrations of vimentin in comparison to freshly isolated normal SMCs. The present results indicate (a) that morphological dedifferentiation of SMCs in aortic lesions of cholesterol-fed rabbits is associated with an increased proportion of the proteins of the intermediate filaments and a decrease in those of the thin and thick myofilaments as determined with SDS-PAGE, and (b) that similar changes take place when normal SMCs are cultured in vitro. The results also suggest (c) that enzyme-isolated atherosclerotic SMCs proliferate in a primary culture without the lag period that normal SMCs apparently require for dedifferentiation.

Actins↗
PubMed1983

Divergent effects of atenolol, practolol and propranolol on the peripheral metabolic changes induced by dynamic exercise in healthy men.

A study has been made of the effects of intravenous atenolol, practolol and propranolol on the changes induced by exhaustive dynamic physical exercise in blood pressure, heart rate and blood levels of lactate, glucose, insulin, free fatty acids and potassium. The mean endurance of dynamic exercise was reduced by all three beta-blockers, most markedly by propranolol. After all the beta-blockers heart rate showed a similar decrease during the first 60 min of exercise; atenolol caused the smallest reduction at exhaustion. All three beta-blockers lowered the systolic blood pressure during exercise; propranolol was the most active agent both during exercise and during recovery. The diastolic pressure was higher during exercise after treatment with the beta-blockers, especially propranolol. The beta-blockers did not markedly affect the elevation of blood lactate induced by exercise. The increase in blood glucose was abolished by atenolol. Plasma insulin was reduced by exercise after beta-blockade, most markedly after propranolol and practolol. All the beta-blockers were equipotent in reducing up to 60 min the exercise-induced increase in plasma free fatty acids, although at exhaustion propranolol had a significantly greater effect than atenolol or practolol. Serum potassium was higher after propranolol and atenolol than after practolol during exercise and recovery.

Adult↗
PubMed1983

Plasma cholesteryl ester fatty acids in 3- and 12-year-old Finnish children.

Risk factors associated with coronary heart disease were surveyed in a multicentre study carried out in 1979 among children living in different parts of Finland. The survey included analyses of plasma lipids and cholesteryl ester (CE) fatty acids as well as a dietary interview by a 48-hour recall method. The present report gives the plasma fatty acid compositions obtained from 181 3-year-old and 226 12-year-old children and their relations to dietary factors and other plasma lipids. The mean percentages (+/- SD) of CE linoleate in the 3- and 12-year-old children were 49.2 +/- 5.2 and 5.10 +/- 51.0%, respectively. Differences in CE fatty acid composition between the various regions of Finland were relatively small, but there was a trend to higher proportions of polyunsaturated fatty acids in western and urban compared with eastern and rural communities. Among different dietary constituents the daily intake of margarine + oils or butter had the greatest effect on plasma CE fatty acid composition. There was a highly significant positive correlation between the dietary P/S ratio and the percentage of CE linoleate in plasma.

Child↗