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Biomedical subjects

H Saarni

Publications and source records attributed to H Saarni.

At least 37 records · Page 2Linked to original sources
PubMed1980

Synthesis of hyaluronic acid and collagen in skin fibroblasts cultured from patients with osteogenesis imperfecta.

Collagen and hyaluronic acid syntheses were studied in skin fibroblast cultures from patients with osteogenesis imperfecta and age-matched controls by labeling the cultures either with [3H]proline and separating the collagenous proteins with DEAE- and CM-cellulose chromatographies, or double-labeling the cultures with [3H]glucosamine and [14C]glycine and separating radioactive hyaluronic acid from glycoproteins and sulphated proteoglycans by DEAE-cellulose chromatography. The activities of the cell layer hyaluronate synthesizing enzyme complex (hyaluronate synthetase) were also determined. The osteogenesis imperfecta cultures were classified into three variants on the basis of type III collagen synthesis. Type III collagen amounted to approx. 40--50% from total collagen in the first variety and approx. 25--30% in the second variety. No difference was noted in the ratio of type III collagen to total collagen in the third variety in comparison with control cultures. The radioactivities of 3H-labeled hyaluronic acid in DEAE-cellulose chromatograms were compared with those of the 14C-labeled proteins. The ratios ranged 9.2--17.3 in the cultures from the patients and 4.6--8.8 in the control cultures. Hyaluronate synthetase activities were 1.3--2.0-fold higher in the osteogenesis imperfecta cells than in their controls. Increased hyaluronic acid synthesis in skin fibroblasts correlated with the severity of the disease but not with the increase in type III collagen synthesis.

Adolescent↗
PubMed1980

Unusual patterns of benzo[a]pyrene metabolites and DNA-benzo[a]pyrene adducts produced by human placental microsomes in vitro.

Human placental microsomes were incubated with [3H]benzo[a]pyrene (BP) and Salmon sperm DNA and the resulting metabolite-nucleoside complexes resolved by Sephadex LH-20 chromatography. The metabolite pattern was analyzed by high-pressure liquid chromatography (HPLC). The incubates were also co-chromatographed with extracts obtained from incubates with rat liver microsomes and [14C] BP. Phenols, quinones and 7,8-dihydrodiol were detected in the placental incubates. Both 9,10- and 4,5-dihydrodiols were very low as compared with control rat liver samples. Placental microsomes catalyzed the binding of BP metabolites to DNA in vitro, giving rise to two main complexes which co-chromatographed with rat liver-produced peaks attributable to 7,8-diol-9,10-epoxide and 7,8-oxide and/or quinones when metabolized further. The nucleoside metabolite peaks attributable to 4,5-oxide and 9-phenol-4,5-oxide were lacking when compared with the binding pattern catalyzed by rat liver. Both the total binding and specific metabolite-nucleoside adducts in the placenta correlated with fluorometrically measured aryl hydrocarbon hydroxylase (AHH) activity and with the amount of dihydrodiol formed. The results demonstrate that both the metabolite pattern and the nucleoside-metabolite complexes formed by the placental microsomes in vitro differed greatly from thos produced by rat liver microsomes. These sstudies also suggest that it is not possible to predict specific patterns of DNA binding from AHH measurements or even from BP metabolite patterns, especially when comparing different tissues and species.

Aryl Hydrocarbon Hydroxylases↗
PubMed1980

Cortisol decreases the synthesis of hyaluronic acid by human aortic smooth muscle cells in culture.

The effect of cortisol on the synthesis of glycosaminoglycans (GAGs) was studied in cultured human aortic smooth muscle cells. Cortisol, at a level slightly exceeding the physiological concentration (10(-6) M), decreased the synthesis of hyaluronic acid (HA) by 50% but had no significant effect on the synthesis of sulphated GAGs. The ratio of HA to sulphated GAGs decreased by 47%. These effects were most marked in the fraction secreted into the culture medium. Cortisol neither affected the activity of the hyaluronic acid synthesizing enzyme complex in a cell-free system nor the molecular weight distribution of hyaluronic acid. We suggest that the atherogenity of cortisol and stress may be associated with their effect on the synthesis of HA by the smooth muscle cells of the arterial wall.

Aorta↗
PubMed1980

Effect of five anti-inflammatory steroids on collagen and glycoaminoglycan synthessis in vitro.

The effect of five anti-inflammatory corticosteroids, i.e. hydrocortisone, hydrocortisone 17-butyrate, betamethasone 17-valerate, nicocortonide acetate and nicocortonide, on the synthesis of hyaluronic acid, sulphated glycosaminoglycans and collagen by cultured skin fibroblasts was studied. As inhibitors of all these parameters the steroids could be arranged in order hydrocortisone < hydrocortisone 17-butyrate < betamethasone 17-valerate, nicocortonide acetate and nicocortonide. The corticosteroid concentrations required for inhibition of hyaluronic acid were very low as compared to those required for inhibition of sulphated glycosaminoglycan and collagen synthesis.

Anti-Inflammatory Agents↗
PubMed1980

Serum lipoprotein composition, hormones, and the synthesis of glycosaminoglycans by human aortic smooth muscle cells.

The synthesis of hyaluronic acid (HA) and sulphated glycosaminoglycans (S-GAGs) by cultured human aortic smooth muscle cells (SMC) was measured in the presence of human sera with high LDL-cholesterol concentration (type IIA hyperlipoproteinemic patients) or high HDL-cholesterol concentration (marathon runners and lumberjacks). In addition, the effect of some hormones on GAG-synthesis was studied. As compared to normolipidemic controls, type IIA hyperlipoproteinemic sera decreased markedly the synthesis of HA without affecting the synthesis of S-GAGs. On the contrary, sera with high HDL-cholesterol concentration decreased the synthesis of S-GAGs causing a decrease in S-GAGs/HA ratio. Cortisol in concentrations slightly above the physiological level inhibited the synthesis of HA and increased the S-GAGs/HA ratio. Insulin, and interestingly also sex hormones (estradiol, progesterone, testosterone) had no clear effect on GAG-synthesis. It is known that there is an increased S-GAGs/HA ratio in early atherosclerotic lesions. Our results suggest that the determination of this ratio in SMC cultures provides an useful method of studying the atherogenity and antiatherogenity of various sera and hormones.

Aorta↗
PubMed1979

Effect of sera from hyperlipidemic subjects and high-density lipoproteinemic runners on the synthesis of DNA and glycosaminoglycans by cultured human aortic smooth muscle cells.

Effects of hyperlipidemic, normolipidemic and high-density-lipoproteinemic (HD lipoproteinemic) sera from active runners were studied on cultured human aortic smooth muscle cells. The synthesis of DNA, hyaluronic acid and sulphated glycosaminoglycans (GAGs) in the presence of the various sera was measured by the incorporation of [3H]-thymidine and [3H]-glucosamine. The HD lipoproteinemic sera from runners stimulated the synthesis of DNA and sulphated GAGs less than normolipidemic and hyperlipidemic sera. The hyperlipidemic sera stimulated the synthesis of DNA slightly more than the other sera, but only after a 24 h preincubation. Accordingly, the concentration of HDL-cholesterol in serum was negatively correlated with the synthesis of DNA (r = -0.77, P less than 0.01) and sulphated glycosaminoglycans (r = -0.81, P less than 0.01). The sulphated GAGs/hyaluronate ratio was smaller in the presence of HD lipoproteinemic serum as compared with the other sera. The proliferation of aortic smooth muscle cells and the rate at which they synthesize sulphated GAGs have been considered important during the initiation of atherosclerosis in vivo. The present results suggest that sera having differences in the relative amounts of various lipoprotein fractions differ significantly in their influence on both of these arterial smooth muscle cell functions in vitro.

Aorta↗
PubMed1979

Erythromycin levels in serum during treatment with erythromycin stearate and base.

The serum concentrations of erythromycin during treatment with erythromycin stearate and erythromycin base were compared in a randomised cross-over study with 21 hospital patients. No statistically significant differences between the brands were found in the serum erythromycin levels at any time or in the areas under the serum level-time curve.

Administration, Oral↗
PubMed1978

The decrease of hyaluronate synthesis by anti-inflammatory steroids in vitro.

The effect of anti-inflammatory steroids (prednisolone and derivatives of hydrocortisone, dexamethasone and betamethasone) on the synthesis of hyaluronic acid and sulphated glycosaminoglycans in human skin fibroblast culture was studied. The concentrations of steroids varied between 1 x 10(-10)M and 1 x 10(-6)M. All tested steroids decreased the synthesis of hyaluronic acid to the same final level which was about 40--50% of the controls, but the concentrations required varied between different steroids. The relative inhibitory potencies of the steroids were calculated based on concentrations needed to decrease the synthesis of hyaluronate. When the inhibitory potency of hydrocortisone was calculated as one, the values of the other steroids were: prednisolone 5, hydrocortisone 17- butyrate 20, betamethasone alcohol 30, dexamethasone alcohol 38, betamethasone 17-valerate 350--400, dexamethasone monosodium phosphate and betamethasone disodium phosphate over 400. Hydrocortisone sodium succinate was as potent an inhibitor of hyaluronate synthesis as hydrocortisone alcohol. None of the tested steroids affected the synthesis of sulphated glycosaminoglycans at these concentrations. The changes ovbserved in glycosaminoglycans in the medium were in accordance with the changes in the cell layer. The possible significance of hyaluronate synthesis inhibition by anti-inflammatory steroids is discussed.

Anti-Inflammatory Agents↗
PubMed1977

Amino acids in the synaptic vesicle fraction from calf brain: content, uptake and metabolism.

A synaptic vesicle fraction was prepared from calf brain cortex, containing 10 identified amino acids and two unidentified ninhydrin-positive compounds, one of which is apparently a peptide. The most plentiful amino acids were taurine (1.8 nmol/g original tissue), glutamic acid (1.8), serine (0.9), aspartic acid (0.8) and GABA (0.8); the others identified were cysteic acid (or cysteinesulphinic acid), glutamine, alanine, glycine and lysine. The unknown peptide occurred in a high concentration (about 16 alanine equivalents/g), and contained mainly aspartic acid and serine. Cysteic acid (or cysteinesulphinic acid) also occurred in relatively high amounts, but its peak contained acid-labile impurities. The influx of [14C]glutamate into the vesicles took place by means of non-saturable migration, while two saturable systems having very similar properties were dominant only at low glutamate concentrations. Influx constants for these quantitatively low uptake systems were Km, 34 and 92 micrometer, and Vmax, 33 and 49 nmol/min/g obtained by v versus v/S plot. Almost the same values were also obtained by a 1/v versus 1/S plot. GAD and GABA-T activities in the vesicles were only 1/200th of those in the synaptosomes.

4-Aminobutyrate Transaminase↗