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.

[Nitric oxide and lipid peroxidation as factors in endogenous intoxication in emergency states]. / Oksid azota i perekisnoe okislenie lipidov kak faktory éndogennoi intoksikatsii pri neotlozhnykh sostoianiiakh.

K coefficient which is an integral indicator of the unbalance in the system lipid peroxidation--antioxidant system (LPO-AOS) and content of nitrite, nitric oxide end product, were followed up in 31 patients with concomitant brain injury, in 24 patients with burn injury and 72 patients in hypertensive crisis. Coefficient K was estimated by serum levels of dienic conjugates, malonic dialdehyde, lipid peroxidation degree, alpha-tocopherol, ceruloplasmin on the disease day 1, 3, 7 and 14. Nitrite serum levels rose by day 14 in all the patients and were the highest in hypertensive crisis patients. Coefficient K was significantly elevated in all the patients compared to controls being maximal in patients with concomitant brain injury. Thus, activation of LPO and biosynthesis of nitric oxide contribute much to endogenic intoxication in patients on critical care.

[Vasoactive factors in patients with a severe combined trauma]. / Sostoianie vazoaktivnykh faktorov u bol'nykh s tiazeloi sochetannoi travmoi.

46 patients with craniocerebral trauma combined with chest, abdominal, locomotor injuries were hospitalized to the critical care unit. At admission, blood pressure was low, blood loss reached 28% of circulating blood volume. Serum levels of hydrocortisone, nitrite, the activity of angiotensin-converting enzyme (ACE) were measured at admission, on admission hour 4, 24, day 3 and 7. Vasopressor to vasodepressor ratio (hydrocortisone x ACE/nitrite) was also estimated. It was found that severe combined trauma induces an intensive and long-term rise of blood hydrocortisone (a 3-fold rise at admission). ACE activity was low at all the measurements, nitrite levels were reduced only on day 1 and went up to normal on posttrauma day 3-7. The ratio hydrocortisone x ACE/nitrite was significantly elevated in all tests. It is concluded that in severe combined trauma low blood pressure was unrelated to nitric oxide.

[Evidence of the existence of hemolysin II from Bacillus cereus: cloning the genetic determinant of hemolysin II]. / Dokazatel'stvo sushchestovovaniia gemolizina II Bacillus cereus: klonirovanie geneticheskoi determinanty gemolizina II.

The hemolysin genetic determinant distinct from cereolysin AB genetic determinant (lecithinase and sphingomyelinase genes) has been cloned in Escherichia coli and Bacillus subtilis cells as an EcoRI fragment (2.9 kb) of Bacillus cereus VKM-B771 chromosome DNA. The hemolytic product encoded by the cloned DNA fragment possessed all the properties of hemolysin II known to date: it was not inhibited by cholesterol, exhibited the Arrhenius effect, and had a relatively long (in comparison with cereolysin) lag period in erythrocyte lysis. The cloned DNA fragment was concluded to contain the gene of hemolysin II from B. cereus. In contrast to previous suggestions that hemolitic activity ascribed to hemolysin II is due to the combined action of sphingomyelinase and lecithinase, the results obtained present convincing evidence that hemolysin II is an independent B. cereus hemolytic factor different from cereolysin AB.

[Nucleotide sequence of phospholipase C and sphingomyelinase genes from Bacillus cereus BKM-B164]. / Nukleotidnaia posledovatel'nost' genov fosfolipazy C i sfingomielinazy Bacillus cereus BKM-B164.

A BamHI-EcoRV DNA fragment, containing tandemly arranged genes for the Bacillus cereus VKM-B164 phosphatidylcholine-specific phospholipase C and sphingomyelinase, has been cloned and sequenced in pUC19 plasmid (EMBL accession No X64141). The obtained gene sequences have been compared with those the B. cereus strains SE-1, IAM-1208 and GP-4 reported previously. Both phospholipase C and sphingomyelinase gene sequences of the VKM-B164 strain were found to be identical to those of the strain SE-1 and to differ from the sequences of GP-4 and IAM-1208 strains, containing another version of the gene sequences.

[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.