Search PubMed⌕ Search

Biomedical subjects

P Koivistoinen

Publications and source records attributed to P Koivistoinen.

At least 19 recordsLinked to original sources
PubMed1991

Transport of feed selenium to different tissues of bulls.

The effects of different types of Se supplementation on the selenium concentration of beef, bovine internal organs and some other tissues were studied. The animals (thirty-two bulls) were kept in four dietary groups from birth until to the age of 13-14 months, and fed on rations containing either 0.03 mg Se/kg (basic level in local feeds), 0.25 mg inorganic Se supplemented as sodium selenite, or 0.25 or 0.4 mg/kg plant Se in dry matter from feed produced by spraying with sodium selenite. Samples of four muscles and ten other tissues and organs were taken at slaughter. Se was determined by an electrothermal atomic absorption method. Se supplementation significantly increased the Se concentration of all tissue samples. The maximum response was caused by the diet containing 0.40 mg/kg plant Se. In muscles, this diet raised the Se concentration by a factor of 10-12. In other samples, the increment was 1.5-7.5 fold, depending on the type of tissue. In general, plant Se raised the Se level more effectively than inorganic Se. Se supplementation did not affect the vitamin E status of muscle tissue.

Animals↗
PubMed1990

Effect of sampling site on fatty acid composition of human breast adipose tissue.

The effect of sampling site and proximity of malignant tumor on the relative fatty acid composition of human breast adipose tissue was studied in 10 cases of breast cancer. The four anatomic quadrants of breast did not statistically significantly differ from each other in relation to any of the 30 fatty acids studied. Proximity of the malignant tumor did not affect the relative fatty acid composition of fat when compared with more distant sampling sites. Representative samples of breast adipose tissue for fatty acid composition analysis can be obtained from tissue adjacent to the tumor.

Adipose Tissue↗
PubMed1989

Carotenoids and retinoids in Finnish foods: dairy products and eggs.

As part of an overall composition study of Finnish foods, the carotenoid and retinoid content of 20 dairy product samples and eggs were determined by HPLC. The total beta-carotene (all-trans beta-carotene plus 15-cis beta-carotene) was quantitated for dairy products. For egg and egg yolk, lutein content was also determined. Only traces of lycopene, cryptoxanthin, and alpha-carotene were present. All-trans retinol and 13-cis retinol were the major retinoids in dairy products. Small amounts of 9-cis, 11-cis, and 9,11-cis retinols were found. High values of both retinol and beta-carotene were found in full fat cheeses and whipping cream: from 179.0 (cheese, Edam-type) to 318.7 micrograms/100 g (whipping cream) and from 86.7 (cheese, Edam-type) to 186.5 micrograms/100 g (whipping cream) for all-trans retinol and total beta-carotene, respectively. The retinol content averaged 16.3, 32.6, and 52.2 and that of beta-carotene 9.6, 16.7, and 3.0 micrograms/100 g in milk (1.9% fat), milk (3.9% fat), and human milk, respectively. The major pigment in eggs and egg yolk was lutein, 619.5 micrograms/100 g in eggs and 1575.8 micrograms/100 g in egg yolk. According to this study, at the present level of consumption in Finland, milk, milk products (excluding butter), and eggs result in a daily intake of about 350 retinol equivalents, and consequently, are a major source of vitamin A.

Animals↗
PubMed1988

Selenium intake and serum selenium in Finland: effects of soil fertilization with selenium.

Since fall 1984 all agricultural multinutrient fertilizers in Finland have been supplemented with sodium selenate in an attempt to improve the nutritional quality of local foodstuffs known to be exceptionally low in selenium. The intervention has been effective from the growing season 1985 and it has affected practically all domestic agricultural products. From 1984 to 1986 the mean Se concentration of different foods increased. The mean Se intake of the population, calculated on the basis of food consumption statistics and from the data of urinary Se excretion, as well as the average serum Se concentration of both urban and rural people increased also during the same period. Enrichment of fertilizers with sodium selenate seems an efficient and predictable way of increasing the Se concentration of foods and the Se intake of people in low-Se areas.

Adult↗
PubMed1987

Relative nutritional availability to rats of selenium in Finnish spring wheat (Triticum aestivum L.) fertilized or sprayed with sodium selenate and in an American winter bread wheat naturally high in Se.

A Finnish national programme to fertilize crops with sodium selenate led us to compare the nutritional availability to rats of selenium in two Finnish spring wheats (Triticum aestivum L.), either fertilized or sprayed with sodium selenate, with that in an American winter bread wheat naturally high in Se. Weanling male rats were given a Se-deficient Torula yeast diet for 4 weeks followed by either continued depletion or repletion for 4 weeks with graded levels of Se as sodium selenite (standard) or wheat (test food). Plasma and liver Se levels and plasma and liver glutathione peroxidase (EC 1.11.1.9; GSH-Px) activities were used as criteria of body Se status. The availability of Se under these conditions was calculated with the point-slope technique at two dietary levels of Se (Expt 1) and with the slope-ratio method (Expt 2). In the point-slope assay, the level of dietary Se fed had a considerable effect on the apparent availability values obtained which made interpretation of the results difficult. In the slope-ratio assay, no difference in the availability of Se from the various wheats was observed when plasma or liver Se levels were used as the response criteria. The Se in the fertilized wheat was somewhat more available than that in the sprayed wheat when plasma or liver GSH-Px activities were the response criteria. Overall, availability values (%) derived by averaging all four response criteria were 86, 77 and 73 for the fertilized and sprayed Finnish wheats and the American wheat respectively (sodium selenite 100). These results show that wheat is a relatively available source of Se to rats regardless of whether its Se content is naturally high or is increased by fertilization or spraying.

Animals↗
PubMed1987

Formula feeding results in lower selenium status than breast-feeding or selenium supplemented formula feeding: a longitudinal study.

Thirty-two infants completely weaned by age 3.2 mo were randomized into two groups. Unsupplemented group was fed cow's milk-based liquid formula containing 3-5 micrograms Se/L. Se-supplemented group received the same formula supplemented with 20 micrograms Se/L. A third group consisted of exclusively breast-fed infants (51 at age 4 mo, 41 at 6 mo, 12 at 9 mo). Mean serum Se concentration in unsupplemented group decreased from 41 to 31 micrograms/L during the first 2 mo and remained constant until age 6 mo increasing gradually thereafter. In Se-supplemented group it increased steadily from 41 to 68 micrograms/L at age 6 mo and remained constant while supplemented formula was used. In breast-fed group it increased steadily until age 9 mo, between the levels of the two formula-fed groups, when it reached the concentration of Se-supplemented group. At age 12 mo no significant differences were present among the three groups.

Animals↗
PubMed1986

Nutritional availability to rats of selenium in four seafoods: crab (Callinectes sapidus), oyster (Crassostrea virginica), shrimp (Penaeus duorarum) and Baltic herring (Clupea harengus).

1. The present study was conducted to determine the biological availability to rats of the selenium in four high-Se seafoods: crab (Callinectes sapidus), oyster (Crassostrea virginica), shrimp (Penaeus duorarum) and Baltic herring (Clupea harengus). 2. Weanling male rats were fed on a Se-deficient Torula yeast diet for 4 weeks followed by either continued depletion or repletion for 4 weeks with 0.05, 0.1 or 0.2 microgram Se as selenite/g, or 0.1 or 0.2 microgram Se as freeze-dried cooked test food/g. Plasma and liver Se levels or glutathione peroxidase (EC 1.11.1.9; GSH-Px) activities were used as indicators of body Se status. 3. Except for oysters, the biological availability of Se in all these seafoods was close to that of selenite (selenite 100%) when the criterion used was either plasma Se level or plasma GSH-Px activity. 4. By the criterion of increased liver Se level of restored hepatic GSH-Px activity, only herring-Se had a biological availability comparable to that of selenite-Se under all conditions tested, whereas crab-Se and oyster-Se were distinctly inferior in this regard. 5. Increasing the amount of crab-Se, oyster-Se or shrimp-Se supplied in the diet from 0.1 to 0.2 microgram/g changed the apparent availability (%) of Se for hepatic GSH-Px restoration from 38 to 78, 22 to 53 and 57 to 90 respectively. 6. The present study demonstrates that the availability of Se in certain foods is a function of the criterion chosen, the level of Se supplied in the diet, and possibly other unknown interacting dietary factors.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Selenium in food and nutrition in Finland. An overview on research and action.

For geochemical reasons Finland is a low-selenium area. In the 1960's several diseases associated with serious Se deficiency were observed in domestic animals. Selenium medication of animals and selenium supplementation of animal feeds from 1969 effectively eliminated these diseases. An extensive study of the trace element content of foods consumed in Finland in the 1970's demonstrated that the dietary intake of selenium was exceptionally low (25 micrograms/day/10 MJ) during the years when domestic grains were used. A study carried out in 1981 showed that supplementation of healthy middle-aged men with high selenium wheat or yeast or selenate double the glutathione peroxidase activity in platelets. Prospective epidemiological studies based on cohorts that were followed in the 1970's suggested that low selenium (less than 45 ng/ml serum) might be a risk factor for cardiovascular diseases and cancer. Technologies to increase the selenium content of foods and feeds were developed and an official decision was reached to add, starting in 1984, sodium selenate to the main fertilizers to increase the selenium content of domestic grain to about 100 micrograms/kg. This measure will increase the average selenium intake above 50 micrograms/d even in the years when grain with a high selenium content is not imported.

Animal Husbandry↗
PubMed1985

Gut microflora interactions with xylitol in the mouse, rat and man.

The influence of dietary xylitol on the quantity and quality of faecal microflora was studied in Wistar albino rats, CD-1 mice and healthy human volunteers. In animals, the effects of xylitol adaptation and of 4-wk xylitol feeding were examined. No major changes in the numbers of total aerobic or anaerobic bacteria, aerobic streptococci, anaerobic streptococci or yeasts were observed, although there was evidence of a dose-dependent decrease in the numbers of aerobic streptococci in the faeces. However, xylitol feeding caused a clear shift in the rodent faecal microbial population from Gram-negative to Gram-positive bacteria. In human volunteers a similar shift was observed even after a single 30-g oral dose of xylitol. All animals were capable of adapting to 20% dietary xylitol and an accompanying enhancement of the ability of caecal and faecal flora to utilize xylitol was observed.

Adult↗
PubMed1985

Selenium status of exclusively breast-fed infants as influenced by maternal organic or inorganic selenium supplementation.

A longitudinal dietary Se supplementation study on lactating mothers was performed to determine the possibilities of improving the Se status of exclusively breast-fed infants. A total of 200 mothers randomized into three groups received either no Se supplements, 100 micrograms of selenite, or 100 micrograms of yeast-Se daily. Maternal and infant serum Se concentrations showed a linear correlation during exclusive breast-feeding. Yeast-Se in the dose administered was safe and more effective than selenite in increasing the Se concentrations of maternal serum and milk, and infant serum. The mean estimated daily Se intakes of the infants were 7.7 +/- 2.2, 8.9 +/- 2.2, and 11.5 +/- 4 micrograms, in the control, selenite, and yeast-Se groups respectively. Though the infant Se intakes of the unsupplemented and selenite-supplemented mothers were below the lower limit of the safe and adequate range as set by the US National Research Council, their serum Se concentrations increased steadily over the 6-mo study period. As maternal serum Se also increased by over 50% during the same period the results suggest that a maternal daily intake of 50-75 micrograms is adequate during lactation.

Breast Feeding↗
PubMed1985

The use of sugar in foods.

Although the main reason for the use of sugar is its sweet taste, sugar has many other functions in food technology. The most important among these are that added sugar in foods acts as a sweetener, preservative, texture modifier, fermentation substrate, flavouring and colouring agent, bulking agent. The various methods of use of sugar are based on its physical and chemical properties. The replacement of sugar by the newly available sweeteners is difficult if the sweetness values or physical and chemical properties of the substitutes differ greatly from those of sucrose.

Chemical Phenomena↗
PubMed1985

Tocopherols and tocotrienols in Finnish foods: human milk and infant formulas.

Individual tocopherols and tocotrienols in human milk, mother's milk substitutes and other infant formulas have been determined by an HPLC method. 107 human milk samples (23 colostral, 22 transitional and 62 mature) obtained from six healthy mothers throughout the lactation were found to contain all the tocopherols, although delta-tocopherol occurred only in traces. A high content of alpha-tocopherol was found in colostrum (average 1.90 +/- 1.62 (SD) mg/100 g), as compared with transitional (0.65 +/- 0.22 mg/100 g) and mature milk (0.47 +/- 0.16 mg/100 g). The content of beta-tocopherol averaged 0.05 +/- 0.03, 0.02 +/- 0.01 and 0.02 +/- 0.01 and gamma-tocopherol 0.11 +/- 0.09, 0.07 +/- 0.04 and 0.07 +/- 0.04 mg/100 g in colostral, transitional and mature milk respectively. The alpha-tocopherol equivalents thus were 1.93, 0.66 and 0.49 mg/100 g; their ratios to the contents of polyunsaturated fatty acids meet the nutritional need of the newborn and young infant: 5.7, 2.1 and 1.4 mg/g in colostral, transitional and mature milk. Mother's milk substitutes and gruel and porridge powders are enriched with tocopherol acetate to vitamin E levels similar to or higher than those in human milk: substitutes contained on average 1.4 mg alpha-tocopherol equivalents/100 g and reconstituted powders 1.1 mg/100 g. The ratio of vitamin E to polyunsaturated fatty acids of these infant formulas was higher than the recommended value of 0.6 mg/g. The average values for alpha-tocopherol equivalents in fruit-berry and meat-vegetable infant formulas were 0.46 and 0.38 mg/100 g.

Colostrum↗
PubMed1978

Isolation, purification, and partial chemical characterization of chromium(III) fractions existing in brewer's yeast and Sabouraud's liquid medium.

An ethanol extract of brewer's yeast which had been cultivated in a medium containing trivalent 51Cr was analyzed for 51Cr compounds by using petroleum ether extraction, gel filtration, cation and anion exchange chromatography and thin layer chromatography. Similar analytical procedures as for the above analysis were used for studying 51Cr compounds formed in the spent culture medium and in a sterile medium. Several 51Cr fractions were isolated from the three chromium sources, but one anionic 51Cr fraction present in the yeast and in the spent culture medium was not found in the sterile medium. Molecular weight estimations of the 51Cr fractions by gel filtration chromatography showed that the 51Cr ion exchange fractions contained several 51Cr compounds. The molecular weights of these compounds ranged from 150 to 1000 daltons and the molecular weights of 51Cr compounds separated from the yeast were markedly lower than those of the corresponding ion exchange fractions isolated from the culture medium. By using thin layer chromatography it was possible to isolate 51Cr compounds from the main bulk of ninhydrin active impurities. The polarity of all 51Cr compounds was found to be greater than that of most amino acids. The 51Cr compounds isolated from the yeast were mixed with 125I-insulin and incubated, after which the solution was eluted through Sephadex G-50 gel to test if binding had occurred. Elution peaks of 51Cr and 125I-insulin showed that 51Cr compounds were not bound to the insulin.

Chromium↗
PubMed1978

Effects of glucose and chromium(III) concentrations in the medium on the uptake of 51Cr by brewer's yeast.

The incorporation of trivalent chromium into S. carlsbergensis as function of time, the effects of chromium and glucose concentrations in the medium on the uptake of 51Cr by the yeast cells, and the effect of chromium on growth of the yeast were studied. 51Cr was taken up by yeast cells most rapidly during the logarithmic growth period in Sabouraud's liquid medium containing 5% glucose. Cells grown in a medium containing only 0.5% glucose at the beginning of cultivation incorporated very little 51Cr, and incorporation ceased when the glucose concentration was reduced to less than 0.1%. Addition of 5% glucose into this culture resulted in a very rapid increase in the 51Cr uptake. The second glucose addition did not notably increase the rate of 51Cr uptake by the yeast. Chromium, reduced yeast growth slightly, however, was not clearly toxic.

Biological Transport↗