Hygienic evaluation of acetone cyanohydrin transformation in water

The study of acetone cyanohydrin (ACH) showed that it is an unstable substance. Its stability in water depends on pH of water and less so on its initial concentration; water temperature and biota are insignificant. Acetone and cyanid-ion, forming from ACH, after 20 days are transformed into a complex of cyan compounds.     

Action of triterpene glycosides of the dammarane series and their aglycones on lipid membranes

The action of the dammarane triterpene glycosides Rb1 and Rg1 and their aglycones 20(S) protopanaxatriole and 20(S) protopanaxadiole from Korean ginseng on permeability of bilayer lipid membranes formed of monolayers was studied. RgI, protopanaxatriole and protopanaxadiole in concentrations of 3, 0.5 and 30 micrograms/ml respectively formed single ionic channels in the water phase on the membrane side containing cholesterol. The channel conductivity was 5 to 30 pSm in 1 M KCl. The ionic channels were more selective with respect to K+ as compared to Cl-. Rb1 was also able to increase the conductivity of the lipid membranes. However, no jumps in the current characteristics of the single channels were detected. All the substances in high concentrations on one side of the membrane independently of the cholesterol content induced fluctuation of the high amplitude current (from several tens of pSm to several hundreds of nSm).     

Effect of chain length on formation of a double-layer structure of Z-(Gly-Pro-Gly)n-OMe oligotripeptides

Effect of chain length on the formation of the double-layered sheet in synthetic oligotripeptides Z-(Gly-Pro-Gly)n-OMe (n = 1,2,3,4) in the solid state has been studied by the IR-spectroscopy method. The major spectral features characteristic for the polymer structure was found in the oligomer spectra beginning with that of hexapeptide (n = 2). So a minimum peptide length when peptide chains are still able to adopt the double-layered sheet conformation in the solid state includes two triplets. The result is similar to that we have revealed early by investigation of the collagen-like triple helix formation in the oligomer series Z-(Gly-Pro-Pro)n-OMe. The double-layered sheet structure of the hexapeptide was found completely regular as that of the polymer. So the formation of the double-layered sheet structure unlike the formation of the triple-helical structure occurs at once without gradual ordering of interpeptide bonds and molecular packing by further increasing of the triplet number in oligomer chains. Additional information concerning specific incorporation of bound water in the double-layered sheet and water influence on peptide packing has been derived from analyses of hydration effect on the oligotripeptide IR-spectra especially on the components of the amide I band.     

Determination of the bearing capacity of piles in permafrost by static penetration

Conclusions 1. The tests that we conducted demonstrated the technical feasibility of the static penetration of plastically frozen soils with temperatures of 0 to –0.4°C by series-produced type SP-59 and SP-72 apparatus.2. According to penetration data, computation of the bearing capacity of piles in plastically frozen soils using the method proposed by Ladanyi indicate good convergence with data derived from the field testing of piles.3. Penetration makes it possible to determine the bearing capacity of piles in plastically frozen soils with a temperature above –0.3°C on which there are no data for the computation in SNiP II-18-76, and the increase their bearing capacity by 25–30% as compared with the SNiP for soils with temperatures of –0.3 to 0.4°C.4. Further research on the development of a technology and methodology for static penetration of plastically frozen soils of different lithologic composition and temperature, and also a more precise definition of a number of parameters , n, and m, which are used in computations of pile bearing capacity, are necessary.State Institute for the Design and Planning of Beds and Foundations. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 18–20, March–April, 1986.     

Expression of functionally active hyman cytochrome P-450c21 (CYPXXIA2) in Escherichia coli and single-stage purification of it using metal-affinity chromatography

Active human cytochrome P-450c21 was expressed in Escherichia coli and purified to homogeneity. To increase expression, cDNA encoding for the N-terminal fragment of cytochrome P-450c21 was modified. Four histidine codons were added to cDNA encoding for the C-terminus of the protein; thus, recombinant protein could have been rapidly and effectively purified by metal-affinity chromatography. Modified human cytochrome P-450c21 was expressed (40-50 nmoles/l of culture according to spectrophotometry) which was able to bind to bacterial membrane. Modifications of N- and C-terminal regions of cytochrome P-450c21 did not change Km and Vmax for hydroxylation of progesterone and 17 alpha-hydroxyprogesterone in reconstituted system. Recombinant cytochrome P-450c21 was purified to apparent homogeneity from Escherichia coli membrane extract by metal-affinity chromatography. Purified cytochrome P-450c21 migrates as a single 54 kD band on polyacrylamide gel and exhibits type I spectral changes during interaction with progesterone and 17 alpha-hydroxyprogesterone. Activity of purified cytochrome P-450c21 was reconstituted with mouse liver microsomal NADPH-cytochrome P-450-reductase and NADPH-regenerating system. Purified enzyme had Km 12.2 and 3.21 microM and Vmax 192.9 and 198 nmoles/min/nmole of P-450c21 for 17 alpha-hydroxyprogesterone and progesterone, respectively. According to titration spectra, dissociation constants for progesterone and 17 alpha-hydroxy-progesterone were 14.7 and 31.1 microM, respectively.     

A case of the successful treatment of a patient with severe craniocerebral trauma combined with hemophilia

The described case with a severe craniocerebral injury in a patient with hemophilia A demonstrated that the initial hypocoagulation does not preclude the development of intravascular blood coagulation. Therefore, in patients with severe brain injury, a more rapid reduction of antihemophilic globulin A is possible, in comparison with that occurring during planned surgery, and, hence, higher doses of cryoprecipitate and longer duration of its infusion are needed. Moreover, this case demonstrated that even in patients with a slight form of hemophilia A the treatment with cryoprecipitate should be continued till the levels of thrombinemia markers are reduced and the concentration of antihemophilic globulin A in the blood stabilized at a level of at least 10%; the dose of infused cryoprecipitate should be reduced gradually.     

A shock reaction from insect bites in patients with urticaria pigmentosa

The examination of 11 urticaria pigmentosa (UP) patients included allergological history, skin prick, scarification tests and intracutaneous tests with noninfectious and bee poison allergens, total and specific serum IgE measurements, in vitro reaction of histamine release from peripheral blood basophils induced by bee poison. The response of mastocytosis patients to insect sting was characterized by a rapid (within 5 min) development of severe systemic reactions or shock. The skin reactions and serum antibodies to bee poison were not registered in 9 of 11 patients. They also had a negative reaction of allergen-specific histamine release from basophils. This gives evidence for nonimmunological, pseudoallergic mechanism of the shock reaction. The latter can be prevented by bee poison immunotherapy. IgE-antibody-mediated allergic reaction to bee sting could not be excluded in 2 patients. For them specific immunotherapy with bee poison, possibly with purified poison preparations containing the allergens alone, are indicated.     

Phenamine sterotypy as a drug-induced model of psychopathology

Stereotype movements in cats following the administration of bid dosages of phenamine is accompanied by crude disorders of conditioned avoidance with an increase of intrasignal reactions, a weakening of differentiated inhibition and an inhibition of avoidance responses due to low frequency irritation of the caudate nucleus. Caffeine even in large dosages does not possess such properties. Phenamine as in caudectomia decreases the amount of monomodel neurons in the neocortex, as well as group postdischarges in the caudate response of neurons. It is assumed that many indices of phenamine stereotypicity, as a possible model of psychopathology, may be explained by disturbances of the filtering and retention functions of the caudate nucleaus.     

The phenotypic and genetic structure of the Ukrainian Grey breed of cattle

A comparative analysis of phenotypical characteristics, the polymorphism of erythrocyte antigens and genetic-biochemical systems in the groups of Ukrainian Grey cattle, bred in Ukraine and Russia was carried out in different years. Data have been obtained on peculiarities of genetic structure of Ukrainian Grey cattle and on certain breed distinctions in the space and time.