Disorders of cholecalciferol metabolism in old egg-laying hens.

It has been reported that the rate of cracked or soft-shelled eggs markedly increases in old laying hens. We investigated the effect of age on cholecalciferol metabolism in different age groups of laying hens. The egg production rate in hens more than 500 days old was maintained within a range of about 70% of that in young hens (230-320 days old), whereas the rate of cracked or soft-shelled eggs increased markedly with age.

Differentiation of mouse myeloid leukemia cells induced by 1 alpha,25-dihydroxyvitamin D3.

Mouse myeloid leukemia cells can be induced to differentiate into macrophages in vitro by 1 alpha,25-dihydroxyvitamin D3, the active form of vitamin D3. The minimal concentration of 1 alpha,25-dihydroxyvitamin D3 to induce the cell differentiation was 0.12 nM.

[Intramuscular pressure and muscle blood flow during and after contraction (author's transl)].

In order to investigate the effects of intramuscular pressure on muscle blood flow changes during and after isometric contraction, experiments were conducted in anesthetized rabbits. Simultaneous measurements of muscle blood flow with a heated thermocouple technique and intramuscular pressure with a 'multi-hole wick catheter' connected to a transducer were done in the quadriceps muscle. The muscle contraction was caused by stimulating the femoral nerve using supramaximal square voltage pulses (7-9V, 0.

Vitamin D metabolism and its possible role in the developing chick embryo.

The relationship between bone formation and vitamin D metabolism was investigated in the developing chick embryo. Fertilized White Leghorn eggs were incubated at 38 degrees C in an incubator for 21 days. The fresh weight and calcium content of embryonic tibiae began to increase at day 12 and attained maximal values at day 19.

Effect of DL-alpha-tocopherol (vitamin E) on the differentiation of mouse myeloid leukemia cell.

The effect of DL-alpha-tocopherol on the differentiation of the mouse myeloid leukemia cell line (M1) was investigated using fluorometry. The reliability of the fluorometric determination was verified by the mutual overlapping of the curves of disappearance of the radioactivity recovered as alpha-tocopherol and the loss of its fluorescence. alpha-Tocopherol solubilized into the culture medium was relatively stable (t1/2 = 147-168 hr).

A high-affinity cytosol binding protein for 1 alpha,25-dihydroxycholecalciferol in the uterus of Japanese quail.

Cytosol fractions prepared from the uterine mucosa of egg-laying Japanese Quail were analysed for binding of the metabolites of cholecalciferol. When the uterus was incubated at 37 degrees C with various radioactive metabolites of cholecalciferol, the nuclear fraction incorporated only 1 alpha,25-dihydroxy[3H]cholecalciferol. When the uterus was incubated at 0 degree C with 1 alpha,25-dihydroxy[3H]cholecalciferol, most of the radioactivity was found in the cytosol.

[Chronic septic granulomatosis imitating exogenic allergic alveolitis (farmer's lung)].

A 17-year-old boy demonstrated clinical and immunological signs of exogenic allergic alveolitis (farmer's lung). The patient grew up in the country and suffered from recurrent "pneumonia." In his serum precipitins were detected against Micropolyspora faeni, Aspergillus fumigatus and hay.

Higher activity of oxidative drug demethylation in the liver microsomes from dystrophic mouse.

The activities of NADPH-dependent oxidative demethylation of aminopyrine and other methyl compounds in the liver microsomes from dystrophic mice were found to be about 30% higher than those of the normal mice. Consumption of reduced pyridine nucleotides during the demethylation reactions was also significantly larger in the dystrophic mouse system than in the normal mouse system. The synergistic effect of further addition of NADH on the oxidative demethylation in the reaction system with NADPH, however, was not significant in either the normal or the dystrophic mouse system.