[To 20-years anniversary of Chernobyl catastrophe: an attempt to study the vitamin, calcium, iron and selenium status of children and adult population in Slavutich and to correct elicited deficiencies].

The article concisely illustrates the vitamin and mineral state of population of town of Slavutich, including personal of Chernobyl Nuclear Power Station, children of pre-school age and pregnancy women, studied in 1992. Vitamins and minerals deficiency in the main of C and B vitamins and selenium was revealed in all the studied groups. Appropriate measures were developed and introduced to eliminate the detected dusturbances; but however some unsolved problems remained. Taking into account the forthcoming 20th anniversary of Chernobyl disarter, the authors of the come back to considering the obtained data in hope to atlract attention of medical scientific and public to the remained unsolved problems of micronutrient deficiency.

[Possible role of free radicals in the transformations and mechanism of physiological action of vitamin D]. / O vozmozhnoi roli svobodnykh radikalov v prevrashcheniiakh i mekhanizme fiziologicheskogo deistviia vitamina D

Deficiency of vitamine D is accompanied with a decrease of ESR signal intensity from g = 2.003, as well as of the signals with g = 1.94 and gav. = 2.25 in the liver and kidneys of young rats. Injection of 2.5 g ergocalciferole (vitamine D2) to these animals results in a complete or partial normalization of the intensity of these signals during 6--16 hrs and an increase of the ESR signal intensity from g = 2.003 in small intestine mucosa.

[Role of excessive phosphorus consumption in the development of aortic calcinosis]. / Rol' uzbytochnogo potrebleniia fosfora v razvitii kaltsinoza aorty

The calcium and phosphorus content was studied in the blood serum and in the aorta of rats fed with varying Ca:P ratio in their diets (2:1; 1:1; 1:2; 1:3). In rats kept on a 1:3 Ca:P diet hypocalcemia, hyperphosphotemia and intensive calcination of the aorta was observed. Some accumulation of calcium in the aorta was noted also with a 1:2 Ca:P diet. The possible role of excessive phosphorus consumption is discussed as a factor contributing to the development of aortic calcinosis, emphasizing the need to precise and carefully maintain an optimum Ca:P ratio in the diet of normal individuals and in that of cardiovascular patients.

[Specific and nonspecific immunity indices in a varying vitamin E allowance in rats]. / Pokazateli spetsificheskogo i nespetsificheskogo immuniteta pri razlichnoi obespechennosti krys vitaminom E.

Vitamin E deficiency within 1.5 and 3 months did not cause in rats any significant immunological impairments in natural and specific immunity. At the same time, after additional administration of vitamin E into rats at a dose of 100 IU within 3 days, the mass of thymus was increased, blasttransformation activity of lymphocytes was stimulated as well as an increase in titres of normal Vi-antibodies and activation of lysosomal enzymes in blood serum were also detected.

[Metabolism of 3H-25-oxycholecalciferol in rats with experimental fracture of the femur]. / Obmen 3H-25-oksikholekal'tsiferola u krys s éksperimental'nym perelomom bedra.

At the third day after femur fracture concentration of 3H-25-hydroxycholecalciferol [3H-25(OH)D3], intraperitoneally administered into rats within 18 hrs before killing, was increased in kidney and small intestine mucosa by 25% and 60%, respectively, as well as incorporation of the label into 1,25(OH)2D3 in blood serum and small intestine mucosa was increased by 50% and 70%, respectively, as compared with intact controls. Binding of 3H-25(OH)D3 was increased 2-3-fold in diaphyses and epiphyses of impaired bones within 3 and 10 days after the fracture. Similar, but less distinct accumulation of 3H-25(OH)D3 was observed in unimpaired femur of rats with the bone fracture. Incorporation of the label into 1,25(OH)2D3 and 24,25(OH)2D3 was increased 1.5-2-fold in epiphyses of the impaired bone as well as in epiphyses and diaphyses of intact femur of rats with the bone fracture at all the periods studied (3, 10, 28 days after the fracture).

[Comparative study of the hemolytic action of group D vitamins]. / Sravnitel'noe izuchenie gemoliticheskogo distviia vitaminov gruppy D.

Hemolytic effects of the vitamins of the D group (ergocalciferol - D2, cholecalciferol - D3, and 1 alpha-hydroxycholecalciferol - 1 alpha-OH-D3) were compared using rat erythrocytes. The latent period of hemolysis, caused by 1 alpha-OH-D3 was approximately 3-fold shorter as compared with the hemolysis caused by D2 or D3. Apparent values for energy of activation of hemolysis, estimated at 30-45 degrees, constituted for D2 - 23.2 kcal/mol, D3 - 25.3 kcal/mol, 1 alpha-OH-D3 - 13.1 kcal/mol. Despite the higher hemolytic activity, the rate of 1 alpha-ON-D3 autooxidation was distinctly lower than that of D3.

[Experimental vitamin D deficiency with different dietary calcium-phosphorus ratios]. / Eksperimental'naia nedostatochnost' vitamina D pri razlichnom sootnoshenii kal'tsiia i fosfora v ratsione.

Excess of phosphorus (the ratio Ca : P = 1 : 2) in a diet of growing rats strengthened such manifestations of vitamin D insufficiency as hypercalcemia and inhibition of animal growth. The data obtained suggest that excess of phosphorus is apparently important for pathogenesis of rachitis and the optimal ratio Ca : P should not be ignored in child diet.

[Changes in phosphorus-calcium metabolism in experimental renal insufficiency and after administration of dihydrotachysterol and thyrocalcitonin]. / Izmeneniia fosforno-kal'tsievogo obmena pri eksperimental'noi pochechnoi nedostatochnosti i vvedenii digidrotakhisterina i tirokal'tsitonina

Development of experimental chronic renal insufficiency in rats was accompanied by an increase in concentration of residual nitrogen and phosphorus in blood and also by a decrease in intestinal absorption of Ca2+, however, no hypocalcemia was observed and the alkaline phosphatase activity was unaltered in blood serum. At the same time the renal insufficiency caused in some animals metastatic calcification of aorta and kidney, which was manifested by increased calcium concentration in these tissues. Administration of dihydrotachysterol increased the active transport of Ca2+ in rat intestine at the later steps of the impairment and led to development of moderate hypercalcemia and particularly to an increase in the degree of calcinosis of aorta and kidney. Administration of thyrocalcitonine did not prevent the hypercalcemia and calcinosis of internal tissues.

[Functional activity of mitochondria and intensity of nucleic acid and protein synthesis in rat liver and small intestine mucosa with different supplies of vitamin D]. / Funktsional'naia aktivnost' mitokhondrii i intensivnost' sinteza nukleinovykh kislot i belka v slizistoi obolochke tonkikh kishok i pecheni krys pri razlichnoi obespechennosti vitaminom D.

Decrease in total content of mitochondrial protein in mucosa of small intestine, an alteration of distribution of the protein between the fractions of mitochondria, distinct decrease in the respiratory activity of mitochondria and in the activity of succinate- and NADH-dehydrogenases were observed in rats deficient in vitamin D. Deficiency in vitamin D was accompanied by decreased incorporation of labelled precursors into total, nuclear and mitochondrial DNA and RNA by 20-50% and into mitochondrial proteins--by 50% in mucosa of small intestine; these patterns were unaltered in liver tissue. Administration of ergocalciferol (at a dose 1000 IU) into rats normalized the impairments studied, whose alteration correlated with the increase of calcium concentration in blood serum.

[Comparative study of the biological activity and toxic effect of 1alpha-hydroxycholecalciferol and ergocalciferol in rats]. / Sravnitel'noe izuchenie biologicheskoi aktivnosti i toksicheskogo deistviia 1alpha-oksikholekal'tsiferola i érgokal'tsiferola na krysakh.

Single administration of 0.25 microgram of sunthetic Ialpha-hydroxycholecalciferol (IalphaOHD3) into nephrectomized rats, maintained at D-avitaminous diet, improved the active transport of calcium ions against the concentration gradient in small intestine of these animals, whereas ergocalciferol was biologically inactive under the same conditions. Administration of IalphaOHD3 during 5 days at a dose 0.025 microgram normalized calcium content in blood serum of rats with D-avitaminosis, Increased doses of IalphaOHD3, administered into intact animals, caused transient hyperphosphatemia, hypercalcemia, calcinosis of internal tissues (kidney heart, aorta) as well as death of some animals. IalphaOHD3 exceeded 400-fold the hypercalcemic and calcinose effects of ergocalciferol. LD50 for IalphaOHD3 was equal to 100 microgram/kg, if it was administered during 5 days per os. Tissue calcinosis was developed after administration of a daily dose 10 microgram/kg, moderate hypercalcemia was caused by a daily dose 1 microgram/kg or 0.25 microgram per an animal; this amount is only 10-fold higher as compared with the physiologic requirement. Ergocalciferol caused hypercalcemia and metastatic calcification only at a dose 4000 microgram/kg. Clinical use of IalphaOHD3 at doses, exceeding the physiologic requirements, has to be prohibited due to high activity of the preparation and to toxicity of its increased doses.

[Effect of 24,25-dihydroxycholecalciferol on chemical composition of the rat bone tissue during hypokinesia]. / Vliianie 24,25-dioksikholekal'tsiferola na khimicheskii sostav kostnoi tkani krys pri gipokinezii.

Severe hypokinesia in rats, maintained on rations with the Ca:P ratios from 1:0,5 to 1:3, was accompanied by hypocalcemia, osteoporosis and a slight increase in kidney carcinosis. Decrease in phosphorus consumption (Ca:P = 1:0,5 - 1:1) enabled to prevent these impairments in the intact animals and led to an increase in the rate of bone tissue mineralization in hypokinesia. An excessive utilization of phosphorus (Ca:P = 1:3) caused hypocalcemia, hyperphosphatemia and a slight osteoporotic destructions in bone tissue of intact animals increasing the severity of these impairments in hypokinesia. 24,25-Dihydroxycalciferol (24,25 (OH)2D3) at a daily dose 1.25 micrograms per an animal inhibited the osteoporotic destructions, stimulating mineralization of the diaphyses and epiphyses and corrected the hypocalcemia in rats under conditions of hypokinesia. 24,25 (OH)2D3 at the dose used did not increase nephrocalcinosis as well as did not exhibit a toxic effect, estimated in hypokinetic rats by alteration in body mass.

[Effect of 1 alpha-hydroxycholecalciferol and of a varying phosphorus requirement on mineral metabolism in chronic renal insufficiency]. / Vliianie 1 al'fa-oksikholekal'tsiferola i razlichnogo potrebleniia fosfora na mineral'nyi obmen pri khronichskoi pochechnoi nedostatochnosti.

Experimental chronic kidney insufficiency caused in rats the impairments of phosphoerus-calcium turnover (hyperphosphatemia and hypocalcemia), osteoporotic alterations in bones (decreas in specific gravity, in content of Ca, P and hydroxyproline) as well as calcinosis of internal tissues, particularly in the impaired kidney tissue. Decrease in phosphorus content of food down to 0.3% inhibited distinctly the development of these impairments and modulated their severity, lowering mortality of the animals with chronic kidney insufficienty. Administration of physiologic doses (0.025 mg) of 1 alpha-hydroxy vitamin D3/(1 alpha OHD3) which is a synthetic analogue of 1,25-dihydroxycholecalciferol (hormonal form of vitamin D synthesized in kidney) into rats with chronic kidney insufficiency (with limited content of phosphorus in the food) did not exhibit any additional curative effect on the patterns of bone metabolism studied; in this case calcinosis was slightly increased and mortality of the animals also increased. After administration of 1 alpha OHD3 into rats with chronic kidney insufficiency, maintained on food containing 1.2% of phosphorus, impairments in phosphorus-calcium turnover were distinctly increased. Osteoporosis and calcinosis were elevated in the impared kidney; this led to death of all the animals within first 2 months of the experiments.

[Activity of certain mechanisms of natural immunity in white rats provided with different amounts of vitamin D]. / Aktivnost' nekotorykh mekhanizmov estestvennogo immuniteta pri razlichnoi obespechennosti organizma belykh krys vitaminom D.

In rats with D avitaminosis some mechanisms of natural immunity were shown to be unaltered (complement, unspecific bactericidal activity of blood serum, content of normal antibodies to Vi-antigen, lysozyme). Pronounced D hypervitaminosis led to an increase in the unspecific bactericidal activity of blood serum, accompanied by the increase in complement and lysozyme in blood serum, whereas content f lysozyme in leukocytes was decreased. The D hypervitaminosis was also accompanied by distinct atrophy of thymus and by inhibition of T-lymphocyte activity.

[Comparative study of the effect of 1,25 dihydroxyvitamin D3 and 24,25-dihydroxyvitamin D3 on calcium homeostasis and bone tissue state in rats during hypokinesia]. / Sravnitel'noe izuchenie vliianiia 1,25-dioksivitamina D3 i 24,25-dioksivitamina D3 na gomeostaz kal'tsiia i sostoianie kostnoi tkani u krys pri gipokinezii.

Preventive administration of vitamin D3 active metabolites 1.25(OH)2D3 and 24.25(OH)2D3 into growing rats, kept under conditions of long-term hard hypokinesia, normalized Ca metabolism and the state of bone tissue depending on the preparations dose and their combination. 1.25(OH)2D3 at a dose of 0.03 microgram per an animal daily augmented effectively the Ca absorption in small intestine, corrected hypocalcemia, increased slightly the bone tissue density and the Ca and P content in the tissue as well as it elevated the volume of spongiosa, width of the epiphysial growth plate (EGP) and the amount of osteoclasts. After an increase of the metabolite dose up to 0.15 microgram hypercalcemia, hyperphosphatemia, intensive resorption of bone tissue, distinct increase in the osteoclasts content and ectopic calcification were observed. Administration of 1.35(OH)2D3 and 24.25(OH)2D3 combination (0.03 microgram and 0.25 or 1.25 micrograms, respectively) or only 24.25(OH)2D3 at a dose of 1.25 micrograms caused a restoration of Ca absorption in intestine and of its level in blood as well as mineral composition, density of bone tissue, volume of primary and secondary spongiosa were normalized, while the EGP width and amount of osteoclasts remained decreased. Synergic effect of 1.25(OH)2D3 and 24.25(OH)2D3 in rats appears to depend on their various functions in regulation of Ca metabolism, in development and remodelation of bone tissue, thus indicating that these metabolites of vitamin D3 should be used simultaneously under conditions of hypokinesia for prophylactic purposes.

[Refining criteria for supplying the body with vitamin C]. / Utochnenie kriteriev obespechennosti organizma vitaminom C.

As shown by mathematical analysis of a dependence of vitamin C excretion with urine on its content in blood as well as by plotting and mathematical interpretation of the variation curves exhibiting distribution of the ascorbic acid detected in blood plasma of persons additionally treated with vitamin C, the values 0.4-0.5 mg/dl of vitamin C (lower limit of normal values) may be recommended as a criterion of the vitamin normal consumption which corresponded to literature data. The value 0.7 mg/dl used in literature is the optimum content of vitamin C in blood. Excretion of vitamin C with urine, corresponding to lower limits of the vitamin consumption, constituted 0.4 mg/h in adults and 0.2 mg/h-in children of 5-14 years old. Metabolism of vitamin C in patients with diabetes mellitus was considerably distinct from that of healthy persons. As a criterion of normal vitamin C consumption in children of 9-13 years old impaired with diabetes mellitus, the content 1 mg/dl of vitamin C in blood plasma should be considered and its excretion with urine--more than 1.8 mg/h.

[Vitamin status of children with diabetes mellitus]. / Vitaminnyi status detei, stradaiushchikh sakharnym diabetom.

A vitamin status was studied in 32 children of both sexes at the age of 9-15 years with insulin-dependent diabetes mellitus within 2-3 years. The adequate consumption of all the vitamins studied was found only in two children. Polyhypovitaminosis was detected in 19% of these children. Deterioration of riboflavin metabolism observed was manifest, as a decrease in the vitamin content in tissues in line with an increase in its excretion with urine. As a result of this impairment metabolism of vitamins B6 and PP was disturbed with development of these vitamins secondary deficiency of the non-alimentary type. Obligatory correction of the water soluble vitamin deficiency in the patients with diabetes mellitus is discussed.

[Vitamin metabolism in children with insulin-dependent diabetes mellitus. Effect of length of illness, severity, and degree of disruption of substance metabolism]. / Obmen vitaminov u detei, bol'nykh insulinzavisimym sakharnym diabetom. Vliianie dlitel'nosti zabolevaniia, ego tiazhesti i stepeni narusheniia obmena veshchestv.

Correlation between the state of vitamin metabolism and the impairments in carbohydrate, lipid and protein metabolism was studied in 35 children of 9-13 years of age with diabetes mellitus of various severity standing for up to 7 years. Deterioration of riboflavin metabolism in insulin-dependent diabetes mellitus, expressed as an increase of the vitamin excretion with urine, was augmented with prolongation of the disease duration; the deterioration was sometimes related to the value of glycemia and glucosuria, being the indicative symptom of the disease. In spite of some limitations in validity of experiments related to insufficient number of children in some groups, a decrease in excretion of 1-methyl nicotinamide with urine was detected in all the children with the comatose state, in acidoketosis and glucosuria (above 20 g/day), whereas normal content of nicotinamide coenzymes was found in erythrocytes. Deficiency in vitamins B1, B6 and C was observed more often (5-100%) in children with elevated content of cholesterol as compared with 7-67% of children exhibiting normal level of cholesterol. Optimization of vitamins B and C consumption in children as well as use of any means for correction of these vitamins deficiency are discussed.

[Providing adults and children with vitamin A and carotenoids in different regions of the CIS]. / Obespechennost' vitaminom A i karotinoidami vzroslogo i detskogo naseleniia razlichnykh regionov SNG.

Population based studies of vitamin nutritional status in Russia, Ukranian, Belarus and Baltic States in 1983-1991 give evidence about satisfied vitamin A nutritional status and insufficient carotenoids nutrition of population. The retinol level below 30 MK2/dl (lower reference level) was revealed in 6% of the adults, 19% of the children and 6% of the pregnant women. The level of carotene below 80 MK2/dl took place in 39% of the adults, 28% of the children and 18% of the pregnant women. Worst vitamin A and carotene nutritional status was detected in adults and children living in Mogilevskaya and Gomelskaya regions suffering from accident on Chernobyl station as well as inhabitants of large industrial centres (Ekaterinburg, Orenburg, Kemerovo, Norilsk, Zaporoz'e) with bad ecological situation It was pointed on probable connection between insufficient consumption of carotene and increased risk of cancer and cardiovascular diseases. It is recommended the realization of large-scale actions upon cardinal improvement of vitamin A and carotene supplying of population.

[Dynamics and mechanism of mineral metabolic disorders in excessive phosphorus content in the diet]. / Dinamika i mekhanizm mineral'nogo obmena pri izbytochnom soderzhanii fosfora v ratsione.

Keeping rats on a ration with a 1:3 proportion of calcium and phosphorus for 2 weeks results in hyperprosphatemia, hypocalcemia and renal calcinosis with uremia. When putting these animals on a food ration with the calcium and phosphorus ratio of 1:1 the concentration of these elements in the blood quickly returns back to normal, while renal calcinosis continues for the whole period of observation (7 months). The growing animals are more sensitive to a phosphorus excess than are the adult ones. An excessive consumption of phosphorus leads to its increased excretion with the urine with concurrent diminution of the calcium excretion. The blood and urine pH then experiences no change, whereas the ability of the turned inside out segments of the small intestine to absorb calcium as against the concentration gradient (active transport) in vitro not only does not diminish, but initially even goes up. It is suggested that the excess phosphorus content in the food ration tends to directly derange absorption of calcium in the intestines, this resulting in the development of hypocalciemia, hyperparathyroidism and calcinosis of the viscera and tissues.

[Effect of vitamin D2 and 1 alpha-hydroxycholecalciferol on bone tissue in rats with femoral fractures]. / Vliianie vitamina D2 i 1 alpha-oksikholekal'tsiferola na kostnuiu tkan' krys s perelomom bedra.

Formation of the callus at the site of a femoral fracture in rats without vitamin D deficiency is accompanied by an increase in the specific mass and mineralization of the unaffected pair bone, which indicates general intensification of the processes of mineralization occurring in the skeleton during fractures. Vitamin D deficiency leads to hypocalcemia, retardation of callus mineralization, and drastic demineralization of the intact thighbone thus pointing to pathological enhancement of skeleton resorption as the main source of calcium required for covering bodily requirements. Like vitamin D2 in a dose of 0.300 microgram, administration of 1 alpha-hydroxyvitamin D3 (1 alpha-HCD3) in a dose of 0.025 microgram daily to rats with femoral fractures kept on the vitamin D-deficient diet provides for effective calcium homeostasis maintenance and mineralization of the callus and unaffected bones. This demonstrates high biological activity of 1 alpha-HCD3 and its efficacy in promoting the processes of mineralization during fractures. The increase in the phosphorus content in the diet until the calcium/phosphorus ratio reaches 1:2 (instead of the optimal 1:1), aggravates hypocalcemia and sharply enhances demineralization of the intact bone in vitamin d-deficient rats with femoral fractures and reduces mineralization of the callus in rats given 1 alpha-HCD3. The data obtained indicate the necessity of reliable correction of potential vitamin D deficiency and optimization of the calcium-phosphorus ratio in the diet and preparations, as well as a possibility of applying 1 alpha-HCD3 in the combined treatment of fractures.