PubMed Health⌕ Search

Biomedical subjects

Z I Abramova

Publications and source records attributed to Z I Abramova.

At least 19 recordsLinked to original sources
PubMed2000

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. I. Synthesis of ferritin and colloidal gold conjugates with monospecific antibodies against neutral Mn2+-dependent DNAase].

Rabbit antibodies against a neutral Mn(2+)-dependent rat liver DNAse were obtained, whose specificity towards DNAse was ascertained by suppression of the enzyme activity both in vitro system and immunoblotting assays. Procedures of synthesis of ferritin and colloidal gold conjugates with antibodies are described. The biological activity of the conjugates proved to be similar to that of the original antibodies.

Animals↗
PubMed2000

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. II. Analysis of ultrastructural localization in epon sections of different organs of the rat].

The use of a conjugate of colloidal gold with monotypic antibodies against a neutral Mn(2+)-dependent DNAse has revealed the enzyme localization in ultrathin Epon sections of glutaraldehyde fixed tissues. Technical procedures involved in fixation, embedding, and immune reactions are described. DNAse has been established in the nuclei in both normal and regenerating liver. A protein, immunologically close to DNAse, has been identified in the nuclei of a lymph node, thymus, spleen and cerebellar cortex.

Animals↗
PubMed2000

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. III. Visualization of DNAse binding to isolated chromatin].

Neutral Mn(2+)-dependent DNAse is localized on isolated chromatin structures in both normal and regenerating rat liver. The enzyme was revealed located along the whole length of nucleosomal chain and in hypernucleosomal structures. However, as concerns the quantity of the enzyme, it was distributed unevently along the chromatin, thus reflecting the pattern of different functional states of native chromatin. According to biochemical and immunohistochemical data, DNAse can hydrolyse in vitro only one-stranded DNA. One of possible explanations of the observed differences in DNAse binding with native DNA chromatin and its inability to adsorb on native DNA in vitro may be the presence of hypothetical DNA-binding proteins in native chromatin making complexes with DNAse and thereby responsible for immobilization of the enzyme on chromatin structures in vivo.

Animals↗
PubMed1995

[The interaction of the Ca2(+)- and Mg2(+)-dependent DNAses of sea urchin embryos with DNA].

The interaction between Ca2+- and Mg2+-dependent DNAse from Strongylocentrotus intermedius embryos with native DNA was studied by an immunological electron microscopy method. Colloidal gold-labelling was ascertained to be an endonuclease that reacted along the whole length of the native DNA chain. After the phosphodiester bond hydrolysis the DNA-DNAse complex did not dissociate. The enzyme remained was bound with the terminal DNA fragment. Kinetics of enzymatic hydrolysis of DNA suggests the presence in the molecule of DNA of some specific nucleotide sequences which are recognized and split by the enzyme.

Animals↗
PubMed1990

[The determination of the nature of the interaction of neutral Mn2+-dependent DNAse with DNA by immunoelectron microscopy].

The interaction of neutral DNAase with native and denatured DNA was shown by immunoelectron microscopy method with the help of colloidal gold. The neutral DNAase of the rat liver nuclear chromatin is absorbed both to denatured DNA, in which the denatured regions are arranged at 5'-3' ends, and to DNA in which these regions are distributed along the whole molecule.

Animals↗
PubMed1988

[Localization of neutral Mn-dependent DNAse in rat hepatocytes. An immunofluorescent study].

Rabbit antibodies against the Mn-dependent DNAse were obtained. The specificity of the anti-DNAse antibody was established by the enzyme inhibition in vitro. The enzyme activity was inhibited by more than 75 and 54% using rabbit antisera and affinity-purified IgG. Localization of the enzyme in the rat hepatocyte nuclei was studied by indirect immunofluorescence.

Animals↗
PubMed1988

[Ultrastructural localization of neutral DNAse in hepatocytes by immune electron microscopy using colloidal gold].

A method for obtaining of the colloidal gold with particles 20 nm in diameter is described. The use of conjugate of colloidal gold-specific antibodies to the neutral DNAase is shown to determine the DNAase localization on ultrathin epontic sections of rat liver fixed by glutaraldehyde. The conditions of fixation, filling and immune reactions are described. The neutral DNAase has been found to localize mainly in heterochromatin.

Absorption↗
PubMed1987

[Effect of Ca2+, Mg2+-dependent deoxyribonuclease on DNA synthesis in cell nuclei from embryos of the sea urchin Strongylocentrotus intermedius].

The sea urchin embryo nuclei which retained their ability to maintain the DNA synthesis in an in vitro system were isolated. The DNA synthesis isolated nuclei was shown to be an ATP-dependent process which is inhibited by low concentrations of actinomycin D, a polymerase alpha araCTP inhibitor. The newly synthesized DNA is represented by short fragments of about 4S. After addition of Ca2+, Mg2+-dependent DNAase to sea urchin embryo nuclei, the synthesis of short DNA fragments is enhanced. This stimulating effect of Ca2+, Mg2+-dependent DNAase is ATP-dependent and is observed only within a narrow range of enzyme concentrations (of the order of 1-5 units of DNAase activity per ml of incubation sample). The increase in the enzyme concentration to 10 or more units of activity results in the depression of DNA synthesis. It is concluded that DNA replication in sea urchin embryo nuclei depends on the presence of active DNAases as well as on the number of accessible initiation sites of DNA replication.

Adenosine Triphosphate↗
PubMed1984

[Antibacterial therapy of pyelonephritis in pregnant women].

To determine the optimal schemes of rational antibacterial therapy of pyelonephritis gravidarum with ampicillin and cephuroxim, assays of the patient urine and studies on the pharmacokinetics of the drugs were performed. The bacteriurea levels were estimated in 264 women with Gould's method in modification of Ryabinsky and Rodoman. The causative agents of the disease were isolated from the urine of 92 pregnant women. Sensitivity of the isolates to 9 antibiotics was tested with the use of standard paper disks and the method of serial dilutions in solid media. The pharmacokinetics of ampicillin and cephuroxim in the blood and urine of 97 patients was studied for 6-8 hours after parenteral administration of the antibiotics in doses of 500 mg. Comparative analysis of the pharmacokinetic parameters of the antibiotics in the blood and urine of the patients, the antibiotic MICs for the disease causative agents and the clinical course of the disease suggests that pyelonephritis gravidarum should be treated with ampicillin and cephuroxim on doses of 500 mg injected intramuscularly 4 and 3 times a day respectively for 7-8 days in combination with antiinflammatory therapy.

Ampicillin↗
PubMed1980

[Antibacterial therapy and hospital infection].

Relationship between the etiological structure of hospital infections and antibacterial therapy was analysed. It was found that the wide use of antibiotics in medical practice changed the etiology of hospital infections in direction of predominance of gramnegative conditionally pathogenic bacteria, which are characterised by high resistance to antibiotics. Data on changing of staphylococcal sensitivity to antibiotics during the recent years are presented. The causes of this process are analysed.

Anti-Bacterial Agents↗