Mössbauer and X-ray studies of Fe-powder mechanically alloyed with C using power ultrasonics.

The Mössbauer and X-rays analysis of as-received Fe-powder and Fe-powder mechanically alloyed with C using high power ultrasonics were carried out. The powder blend of Fe-powder and graphite was processed in He environment during 5 to 50 h. The dissolution of carbon in iron particles and inhomogeneous distribution of C atoms in crystallites was revealed. The ultrasonic milling of the f.c.c. Fe-Ni-powder with graphite was carried out. As established, the saturation of iron particles with carbon under ultrasonic milling occurs for much shorter time as compared to the high-energy ball milling.

[Anti-tumor activity of the polysaccharide mannan, and its effect on the dynamics of cyclic nucleotides in tissue]. / Protivoopukholevaia aktivnost' polisakharida mannana i ego vliianie na dinamiku tsiklicheskikh nukleotidov v tkaniakh.

Mice with transplantable Harding-Passey melanoma were treated with polysaccharide mannan (50 mg/kg), cyclophosphamide (20 and 100 mg/kg) and their combinations. Mannan proved to possess considerable antitumor properties. It potentiated the therapeutic effect of cyclophosphamide and diminished its toxicity. Mannan treatment resulted in two-phase dynamics of cyclic nucleotide system in mouse liver and melanoma.

[Effect of thymalin on the cyclic nucleotide system in the mouse spleen]. / Vliianie timalina na sistemu tsiklicheskikh nukleotidov v selezenke myshei.

The effect of the thymus preparation thymalin (1000 micrograms/mouse, i.p.) on the system of cyclic nucleotides in the spleen has been studied. The preparation produced two-phasic changes in the content of cAMP and cGMP, as well as in the activity of cAMP phosphodiesterase. The changes in the spleen cAMP content are consequent on those in the activity of phosphodiesterase.

[Regulatory role of DOPA and components of the cyclic adenosine-3',5'-monophosphate system]. / O reguliatornoi roli DOFA i komponentov sistemy tsiklicheskogo adenozin-3'-5'-monofosfata.

It was shown on albino mice that when DOPA-3H (20 muCi/mouse) was administered before nonradioactive DOPA (1 mg/mouse) tritium accumulation in the tissue of Harding-Passi's melanoma of these mice proved to increase. Melanoma radioactivity in this experimental group was double that in the tumour tissue of the animals to which DOPA-3H alone was administered. Examination of the adenylate cyclase, phosphodiesterase activity and of the level of cAMP in melanoma of mice 2 hours after DOPA administration (1 mg/mouse) showed accumulation of cAMP and an increase in the phosphodiesterase activity; as to adenylate cyclase activity--it fell. It is suggested that DOPA realizes its effect not only as melanin precursor, but also through the cAMP system, influencing the melanogenesis enzymes activity.