Activation of key proenzymes of the blood coagulation system by the fibrin E fragment

Plasminogen and prothrombin are key proenzymes of fibrinolytic and clotting system. It is known that they can be activated by indirect activators streptokinase and staphylocoagulase. In this paper it is shown that fibrin E fragment purified from DD-E complex induced catalytic activity in plasminogen and clotting activity in prothrombin. Streptokinase increased 2 times the rate of catalytic activity induction by E fragment in prothrombin. It's possibly that process is one of the factors providing for rethrombosis after thrombolytic therapy of myocardial infarction.     

Tankyrase activity in organs and tissues of mice

Tankyrase, one of the NAD⁺ ADP-ribosyltransferases, is a target for drugs developed for their anticancer and other pharmacological activities. We designed an assay for estimation of the inhibition or activation of the enzyme in pre-clinical studies. In mice, the highest specific activity of tankyrase was observed in thymus, spleen, pancreas, and bone marrow. In murine liver, tankyrase is active in ontogenesis and during reparative regeneration; however, the basal activity is hardly detectable in normal liver and most of other organs of adult animals. We suggest that tankyrase is a part of the tissue growth and repair machinery, while its age-dependent inhibition, when an organism stops growing, turns on phenoptosis.     

A medico-genetic study of isolates in Uzbekistan. III. Results of a cytogenetic study]

The cytogenetic examination of the population of the villages of Karakent and Ishan consisted of two directions: the study on the frequency of chromosome aberrations in the culture of lymphocytes and the diagnostics of anomalies and variants of karyotype. The frequency of chromosome aberrations of 40 individuals was studied. It is shown that the frequency of cells with chromosome aberrations of the individuals in different villages does not differ and on the average is 1,4%. The distribution of lymphocyte culture according to the number of aberrations corresponds to that of theoretical Puassonian. Chromatide breaks are the main type of the aberrations. Among 250 karyotypically examined individuals no evident structure reformations were found. In the caryotype of a 7-year old girl trisomia of the 21st autosome was detected. On the basis of differential staining of chromosomes by Hiemse's dye 18 individuals (7,2%) were diagnosed to have insignificant changes in morphology of some chromosomes, considered as variants of caryotype. In the majority of cases these changes were of a family nature. On the medical examination mnay individuals were diagnosed to have different pathological features, though we did not succeed in revealing any correlation between a certain microanomaly of chromosomes and a pathological feature.     

Mitochondrial gene divergence of Colombian Drosophila pseudoobscura

Isolated populations of drosophila pseudoobscura, separated from North American populations by about 2,400 km, were found in Colombia in 1960. We compared for sequences of the small ribosomal RNA (srRNA) gene on the mitochondria between North American and Colombian D. pseudoobscura in order to clarify the age of the Colombian isolates. The North American populations were not genetically different from each other but were genetically different from the Colombian populations. The Mexican strains represent the area from which the Colombian founders might have come. The estimated net nucleotide divergence between Mexican and Colombian D. pseudoobscura indicates that the Colombian population is not an ancient lineage. Phylogenies using both distance and parsimony methodologies reinforced this conclusion. The Colombian samples group together with both methods but, according to the bootstrap analysis, not significantly. It appears that the populations have not been separated long enough for their DNA sequences to show much divergence.      

The effect of melamine salt of bis(oxymethyl)phosphinic acid (melafen) on the growth processes and plasma membrane function in potato tuber cells

The effects of a new synthetic growth regulator, preparation melafen, on the growth processes in potato plant tubers and the H⁺-ATPase activity in cell plasmalemma were studied. It was demonstrated that melafen could both stimulate and inhibit the growth of potato tubers depending on its concentration and the physiological state of the tubers. It is likely that one of the manifestations of melafen action is its influence on the division and extension of apical meristem cells. The growth stimulation caused by melafen is connected with modifications of the plasmalemma of potato tuber cells, namely, the activation of H⁺-ATPase and increase in the membrane proton permeability.     

Relationship of tumor necrosis factor α expression with activation of sphingomyelinase and lipid peroxidation after removal of cholestatic factor

The goal of this work was to study the expression of tumor necrosis factor α (TNFα), sphingomyelin cycle activation, and lipid peroxidation (LPO) processes after the removal of a cholestatic factor in the liver subjected to different durations of cholestasis. Restored bile flow after a 9-day hepatic cholestasis normalized sphingomyelinase (SMase) activity and levels of TNFα and LPO products. The removal of a cholestatic factor after a 12-day cholestasis did not normalize the studied parameters: SMase activity and the levels of TNFα and LPO products remained much higher compared to control. A significant positive correlation between TNFα expression, SMase activity, and LPO rate has been revealed. The obtained data indicate that hepatocyte apoptosis after bile outflow restoration in late cholestasis can be due to the activation of the sphingomyelin cycle, LPO, and TNFα expression. The synergistic interaction can sharply increase the proapoptotic capacity of each of these factors since TNFα activates SMase and LPO, SMase activity depends on the LPO rate, while ceramide, an SMase-produced secondary messenger of apoptosis, can induce oxidative stress.     

The identification of the ceruloplasmin region interacting with the copper transferring menkes ATPase

The interaction was studied of ceruloplasmin (Cp, EC 1.16.3.1), a copper-containing plasma protein, with two synthetic peptides P15 and P16 whose structures correlate with those of the noncytosolic regions of the copper transfer P1 type ATPase (ATP7A), apparently encoded by the Menkes disease gene (Atp7a). Pentadecapeptide P15 and hexadecapeptide P16 were synthesized using the solid phase method. They correspond to fragments of two extracellular loops ATP7A, of which one loop is apparently involved in the copper ion transfer (P16) whereas the otheris not (P15). The protein footprinting showed that P16 binds to a fragment of the ceruloplasmin domain 6. Kinetics of the ceruloplasmin-P16 binding was studied by affinity chromatography on P16 immobilized on a macroporous disk, and theK _d value (1.5￠10⁻⁶ M) of this interaction was determined. The ATP7A involvement in the copper ion transfer to nonhepatocyte cells is discussed. Deceased.     

Changes in the plastid apparatus of apical meristem cells of potato tubers upon growth regulation with jasmonic acid

A comparative ultramorphometric study of the effect of jasmonic acid (JA) on the plastid apparatus in apical cells of potato tubers varying in physiological state was performed. When tubers were treated with JA at forced rest, the plastid apparatus of apical cells decreased in area and plastid proliferation was suppressed. When treatment was performed during growth, the area of the plastid apparatus remained unchanged, division was suppressed, and plastid budding was stimulated in apical cells. There was also a common response to JA that was independent of the physiological state of tubers. JA stimulated the development of the internal membrane system in plastids, reduced the amount of protein inclusions, and increased the portion of plastids having cisterns of the granular endoplasmic reticulum (GER) around their envelopes. The ultrastructural changes in plastids made it possible to assume that JA increases the biosynthetic activity of the plastid apparatus in apical meristem cells of potato tubers.     

Comparison of the cytogenetic effects of cyclophosphamide on monkey lymphocytes in vivo and in vitro

The comparative in vivo and in vitro study of chromosomal aberrations and SCE induced by cyclophosphamide (CP) in macaca rhesus lymphocytes was performed. The dose of mutagenic exposure for quantitative estimation of effects was determined as a product of concentration of alkylating CP metabolites on the exposure time. The mutagenic effect caused by the same doses of CP (CP metabolites) appeared similar in vivo and in vitro. This suggests that the results obtained in adequate in vitro mutagen-testing experiments may be quantitatively extrapolated for the in vivo conditions.     

Unusually high level of chromosome variability in cultured human peripheral blood lymphocytes]

A cytogenetic examination carried out in the inhabitants of Seversk (Tomsk oblast) and workers of the Siberian chemical industrial complex (a complex of nuclear-chemical and fuel plants), living in the same town, revealed unusually high level of spontaneous chromosomal variability both in control and industrial groups (total irradiation doses 1.8 to 3.7 and 9.3 to 15.7 Gy, respectively). The frequencies of cells with chromosomal aberrations (estimated per 100 cells) in control and industrial groups were 4.69, 6.04, and 6.64, respectively, and the total number of aberrations constituted 6.93, 8.47 and 12.06, respectively. These frequencies were several times higher compared to the summarized literature data on the control levels. The high average aberration level was caused by the elevated proportion of chromatid-type aberrations and paired fragments. The reasons for this are unclear. The levels of radioactive background and chemical air pollution in the town were not increased.