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Biomedical subjects

M T Parviainen

Publications and source records attributed to M T Parviainen.

14 recordsLinked to original sources
PubMed1992

Determination of retinyl palmitate and total vitamin A content in liver and liver-based ready-to-eat foods.

The determination of retinyl palmitate and total vitamin A in liver and liver-based ready-to-eat foods is described. The method is very simple as sample preparation is minimal, and the isocratic elution of the C18 column with pure methanol does not necessitate a sophisticated instrumental set-up. The method is accurate with high recoveries (100.6 +/- 9.3%, mean +/- S.D., n = 23), and precise with within-day and between-day coefficients of variation of less than 5.5% (n = 13) and less than 16% (n = 6), respectively.

Animals↗
PubMed1992

Epidemiology of vitamins A, E, D and C in rural villages in Finland: biochemical, nutritional and socioeconomical aspects.

We carried out an extensive health profile analysis in spring-winter 1986 in four Eastern Finnish rural villages as a part of the Healthy Village Study. Altogether, 793 people at working age (20-64 years of age, 427 men and 366 women) participated (80%). Serum lipids (total cholesterol, HDL-cholesterol and triglycerides) and plasma vitamins (vitamin A, D, E and C) were measured as biochemical indicators of health. The dietary habits were reflected in high serum total cholesterol, and in low plasma vitamin C (ascorbic acid, mean 34.4 mumol/l in men, and 51.2 mumol/l in women). The plasma levels of the other vitamins studied were, in general, satisfactory. The mean plasma concentration of vitamin A (retinol) was 2.70 mumol/l in men, and 2.23 mumol/l in women. The gender, high body weight and the use of animal fats had the strongest association to apparent plasma retinol concentrations. The corresponding plasma concentrations of vitamin D (25-hydroxy-D) were 34.1 nmol/l and 35.4 nmol/l, and vitamin E (d-alpha-tocopherol) 22.1 mumol/l and 22.2 mumol/l. Vitamin D deficiency (plasma 25-OHD less than 12.5 nmol/l) was seen in 5% of the subjects. A good vitamin D status was correlated with the use of vitamin supplements, and, surprisingly, with the frequent consumption of alcohol.

Adult↗
PubMed1991

Use of non-collagen markers in osteoporosis studies.

Clinical and research laboratories routinely measure various hormonal and nonhormonal parameters of calcium and phosphorus metabolism, and markers of bone turnover. Such measurements may help clinical decision-making relating to metabolic bone disease and osteoporosis. Molecular biological and cell-culture techniques are being used in basic biochemical research on bone-cell metabolism. Results may aid understanding of normal and abnormal regulation of the bone-cell metabolism, and thus provide further insights relating to the diagnosis and prevention of osteoporosis.

1-Carboxyglutamic Acid↗
PubMed1991

Nephrotoxicity of tobramycin. Value of examining various protein and enzyme markers.

The value of various protein and enzyme markers for the assessment of early nephrotoxicity of tobramycin was studied in 18 patients with febrile infection. The renal clearance of creatinine and the excretion of the following protein and enzyme markers were measured on the first and the last day of the 5-8 day treatment period: albumin, N-acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin, alpha-amylase, lysozyme and retinol-binding protein (RBP). Diurnal excretions of beta 2-microglobulin, lysozyme and RBP, all markers of tubular dysfunction, were already increased on the first treatment day, compared to similar control patients treated with non-aminoglycoside antibiotics and reference values of our laboratory. The excretion of NAG, an enzyme released from tubular cell lysosomes, was not increased initially, but on the last treatment day it was increased most consistently of all the markers studied. Glomerular filtration rate was halved in 5 of the patients. The results suggest that the initial increase in beta 2-microglobulin, lysozyme and RBP excretion is a result of an early tubular transfer block by tobramycin, whereas the late increase in NAG excretion probably reflects the progress of tubular cell damage during the course of aminoglycoside therapy.

Acetylglucosaminidase↗
PubMed1989

Plasma catecholamines: laboratory aspects.

In this review the methods used for analysis of plasma catecholamines in clinical chemical laboratories are discussed. The physiology of catecholamines as well as their measuring indications are discussed, together with concise evaluation of the methods most commonly used, namely indirect radioenzymatic assays or direct determinations by high-performance liquid chromatography combined with either electrochemical or fluorometric detection. The main advantage of radioenzymatic assay is its sensitivity and thus the need for only a small sample. Liquid chromatographic methods in general are less tedious, relatively rapid, and cheap, and omit the use of radionuclides. Both of these methods, however, are subject to a number of analytical errors, which can only be avoided by proper development of methods and skilled use of these methods. Little routine work is done using either radioimmunoassay or gas-chromatography.

Catecholamines↗
PubMed1988

25-Hydroxyvitamin D and vitamin D in human milk: effects of supplementation and season.

Breast-milk 25-hydroxyvitamin D (25-[OH]D) and vitamin D were measured in mothers supplemented with 2000 or 1000 IU (50 or 25 micrograms) of vitamin D/d or with no supplementation. Fore- and hindmilk samples were collected at two stages of lactation (8 and 15 or 20 wk after delivery) and at different seasons. Season affected the levels of 25-(OH)D and vitamin D. The 25-(OH)D levels were higher in hind- than in foremilk. Supplementation had no effect on vitamin D levels. Milk 25-(OH)D levels of mothers receiving either 1000 or 2000 IU (25 or 50 micrograms) vitamin D/d were significantly higher than those of unsupplemented mothers in February and April. In theory, supplementation with 2000 IU (50 micrograms) vitamin D should have increased the calculated antirachitic activity of the milk in winter to the levels of unsupplemented mothers in September; however, responses varied widely among individuals.

Breast Feeding↗
PubMed1988

Plasma haemoglobin determination using chlorpromazine as a non-carcinogenic reagent.

Plasma haemoglobin was assayed with the non-carcinogenic reagent phenothiazine. This method is sensitive and allows the measurement of plasma haemoglobin concentrations in the range 4-500 mg/l with a within-run CV of 2.1%, and a between-run CV of 4.3%. A spectrophotometric scanning method (x) based on the determination of haemoglobin as haemiglobin cyanide using the Soret band at 419 nm correlated well with the phenothiazine method (y): y = 1.07x + 15.8, r = 0.995, n = 31. It was found that the absorbances in the phenothiazine method were markedly dependent on the concentration of phosphoric acid.

Chlorpromazine↗
PubMed1988

Alkaline phosphatase isoenzymes in serum determined by high-performance anion-exchange liquid chromatography with detection by enzyme reaction.

This rapid, reproducible method for separating and determining individual alkaline phosphatase (EC 3.1.3.1) isoenzymes in serum is based on high-performance liquid chromatography with a weak anion-exchange column (SynChropak AX 300). The isoenzymes so resolved are detected by using an on-line enzyme reaction followed by spectrophotometric monitoring at 405 nm of the 4-nitrophenol formed. Complete diagnostic profiles of the various isoenzymes present in normal and pathological sera are obtained within 20 min. The mean (and SD) normal concentrations of the bone B1 and intestinal isoenzymes in serum of adults were 3.7 (4.3) and 4.5 (3.9) U/L, respectively (n = 14), and of the bone isoenzyme B2 and liver isoenzymes L1 and L2, 5.8 (8.6), 33.0 (10.6), and 12.0 (4.8) U/L, respectively (n = 17). Concentrations of the B2 and L1 isoenzymes in adults over age 40 years differed significantly from those in adults younger than 40 years, that of bone isoenzyme being lower (P less than 0.05) and that of the liver isoenzyme being higher (P less than 0.001) in the younger adults.

Adult↗
PubMed1986

Vitamin D status of children and adolescents in Finland.

3-,9- and 15-year-old children were studied in autumn in order to evaluate their serum 25-hydroxy-vitamin D (25-OH-D) concentration and their vitamin D intake. The 25-OH-D was significantly lower in the 15-year-old than in the other children, but it was satisfactory in all groups as compared to the 25-OH-D of healthy, young adults. The mean dietary vitamin D intake as well as the mean total vitamin D intake including supplements was low in all groups of children. With a vitamin D intake as low as in this study, every house-bound child would be at risk of vitamin D deficiency.

Adolescent↗
PubMed1985

Serum albumin assay with bromcresol purple dye.

Serum albumin was assayed with bromcresol purple using routine clinical chemical photometric analysers. Bromcresol purple and bromcresol green dyes were compared, and albumin assays using these dyes were compared to those made by radial immunodiffusion and rocket immunoelectrophoresis. Bromcresol purple seems to be insensitive to all serum proteins except albumin, and this dye is correlated linearly with radial immunodiffusion and with rocket electrophoresis.

Bromcresol Green↗
PubMed1985

Peroral xylitol increases intestinal calcium absorption in the rat independently of vitamin D action.

The absorption of 45Ca from the diet in the presence of xylitol was investigated with 28 adult male rats. The supplementation of the diet with 10% xylitol for 3 weeks augmented the urinary excretion of 45Ca 2.5-fold p less than 0.001), but did not affect the urinary excretion of sodium. The concentration of calcium in the serum remained unchanged. The serum levels of vitamin D metabolites [1,25-(OH)2D; 24,25-(OH)2D, and 25-(OH)D] did not correlate with the augmentation of Ca absorption. The diuretic effect of xylitol and the complex formation between polyols and calcium in rat intestine were considered responsible for the changes in calcium metabolism.

Animals↗