Acta vitaminologica et enzymologica最新文献

Ovariectomy induced a remarkable reduction in the ash content of the femur and histologically a disappearance of the trabecular bone in tibial metaphysis accompanying the decrease of serum calcium level and urinary calcium excretion in young immature rats. Treatment with 1 alpha-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3 and 1,24R-dihydroxyvitamin D3 for 3 months from 7 to 9 months after the ovariectomy dose-dependently increased serum and urinary calcium, bone ash, and histologically partly improved a loss of trabeculae. The 24R,25-dihydroxyvitamin D3 doses, on the other hand, produced no therapeutic effect on the bone disorders in ovariectomized rats, except for the slight effect on the increasing activity of serum calcium.

Vitamin A and beta-carotene contents in 22 samples of precooked foods were determined before and after the use of various reheating techniques. The method used includes saponification by boiling with etOH and KOH, diethyl ether extraction in the presence of BHT as antioxidant, drying under controlled conditions and detection of the vitamins by HPLC. The results suggest good applicability of the procedure to food analysis and show how reheating processes can have a significant influence on the vitamin content of such foodstuffs.

After an anatomical and physiological outline of the organ of Corti, the pathology of the cochlea related to the sensorineural deafness is described. The role of Vitamin A on cochlear function and the effects of Vitamin E in man are then emphasized, on the base of some experimental results. Clinical and therapeutic efficacy of the combination of Vitamin A + E is shown by a number of papers, pointing out a 5-15 decibel improvement of the pure-tone threshold in patients with sensorineural hearing-loss particularly when the auditory troubles are due to presbyaccusis.

Treatment with 5.0 mg/kg of hydrocortisone twice a week for 12 months led to the significant decreased levels of serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D. A histomorphometric evaluation of iliac cortical and trabecular bones was carried out using tetracycline double labelling method and tetrachrome staining. The excessive hydrocortisone treatment produced poor or no fluorescent labelling in the iliac cortex, indicating the absence of any newly established bone. Our present data demonstrate that excessive glucocorticoid may induce bone disorder in dogs by indirectly causing the decrease of serum 1,25-dihydroxyvitamin D3 levels or by directly inhibiting mineral apposition of bone.

Calcium pantetheine-S-sulfonate (PaSSO3Ca) is one of the pantothenic acid derivatives. We examined PaSSO3Ca inhibition capacity of tyrosinase activity in vitro. For the safety evaluation when it will be applied to the human skin, we tested PaSSO3Ca creams to the fifty one patients with skin diseases by 48 hours closed patch test method. And clinical evaluation of PaSSO3Ca creams were performed in fifty patients with chloasma by half side method. Results were as follow: 1, PaSSO3Ca was proved to inhibit the tyrosinase activity in vitro. 2, PaSSO3Ca cream was shown to be safe to human skin. 3, 10% PaSSO3Ca cream lightened the skin hyperpigmentation.

Depletion of ascorbic acid from adrenals, brain and epididymis along with loss in weight were noticed in the state of thyroidectomy. This decrease appears to be due to an effect of thyroidectomy on the membrane integrity since the membrane bound sialic acid was found to be significantly lowered in these tissues as a consequence of the elevated activity of sialidase. Thyroidectomy was also found to cause an adverse effect on the activities of hepatic UDP-glucuronyl transferase and beta-glucuronidase with no alteration in UDP-glucose dehydrogenase.

Folate deficiency and megaloblastic anemia occur in chronic renal failure. However, the possible role of intestinal malabsorption as a cause of the reported deficiency has not been investigated. Therefore, we examined the intestinal absorption of 5-methyltetrahydrofolate in rats made uremic by subtotal nephrectomy using in vivo perfusion technique and in vitro everted sac technique. The results were compared with those obtained in a group of sham-operated rats with normal renal function. The amount of 5-methyltetrahydrofolate absorbed in vivo was significantly lower in the uremic animals as compared to the control group. In contrast, no significant difference was found in the absorption of 5-methyltetrahydrofolate in vitro in the two groups. To mimic the uremic environment, the in vitro studies were repeated using jejunal sacs from normal animals filled with either buffer solution, or sera from uremic patients before and after dialysis. Their results showed a marked suppression of 5-methyltetrahydrofolate absorption with predialysis sera and a significant improvement with post dialysis sera. We conclude that intestinal absorption of 5-methyltetrahydrofolate is impaired in uremia. The results of the in vitro experiments suggest that the observed transport defect is due to some influence of uremic environment rather than to an acquired intrinsic defect of enterocytes in uremia.

The effects of various compounds (0.5%) involved in the butanediol and the glycolytic pathways on riboflavin formation in whole cells of Ashbya gossypii at rest were examined. The addition of acetate, glycerol and diacetyl inhibited riboflavin formation, while the addition of acetoin had no effect on it, and the addition of ethanol, 2,3-butanediol, pyruvic acid and glucose accelerated it. The relation of diacetyl and acetoin to riboflavin formation during resting cell incubation in the presence of 0.5% ethanol and various concentrations of 2,3-butanediol was examined. The results quantitatively revealed a precursor-product relation between riboflavin formation and the formation of diacetyl and acetoin. The results obtained provide evidence that a high flavinogenic agent, ethanol, was converted to acetaldehyde, pyruvic acid, acetoin and diacetyl in this order, that a week flavinogenic agent, 2,3-butanediol, was transferred to diacetyl through acetoin, and that the diacetyl produced can be utilized as the 4-carbon compound for riboflavin formation in the flavinogenic mold, Ashbya gossypii. It remains obscure whether diacetyl is enzymatically involved in riboflavin formation.

In view of the relevance of urinary xanthurenic acid (XA) and zinc in diabetes, a chromatographic procedure has been devised which allows separation of XA from its complex with Zn2+. The procedure involves chromatography on DEAE-Sepharose CL-6B at pH 7.2 with a stepwise Tris-HCl concentration gradient. The ultraviolet absorption difference spectra due to formation of the XA-Zn2+ complex allowed the estimate of the binding molar ratio in the XA-Zn2+ complex. This corresponds to a 1:1 as estimated on the basis of the Hill plot of the experimental data.