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Biomedical subjects

V A Ivanov

Publications and source records attributed to V A Ivanov.

At least 19 recordsLinked to original sources
PubMed1992

[Evaluation of right ventricular myocardial excursions in patients with mitral valve stenosis without pulmonary hypertension].

As many as 23 patients with mitral stenosis were examined intraoperatively, by evaluating of intracardiac hemodynamics and right ventricle myocardial excursions. Before mitral stenosis was corrected, 56% of patients had demonstrated myocardial excursion disorders. After the correction the number of patients with myocardial dysfunction halved. The transition of patients belonging to the group with abnormal myocardial excursions to the group with normal excursions depends on the scope of surgical intervention and pharmacological support. After the correction of mitral stenosis cardiogenic and pulmonogenic complications may mostly be seen in the patients' group showing abnormal myocardial excursions. It is concluded that the symptom of abnormal right ventricle myocardial excursions is of prognostic significance with respect to the development of complications in the early postoperative period.

Adult↗
PubMed1992

[The expression of hetero-organic antigens of kidney origin on the surfaces of cultured rat hepatocytes under the influence of the narrow-band fractions of non-histone chromosomal proteins].

Narrow fractions of nonhistone chromosomal proteins (NHCP) eluted with 0.4-0.5 M NaCl from the phosphocellulose column stimulate expression of hetero-organic antigens of kidney origin on the membrane of intact hepatocytes cultured in suspension. These fractions of NHCP were isolated from the intact rats kidney, from cells of hepatoma 27 and Zajdela hepatoma, and from the carcinogenic liver after a single diethylnirozamine injection. The membrane hetero-organic antigens were identified by means of indirect immunofluorescence using specific immune serum.

Animals↗
PubMed1991

Authentic reverse transcriptase is coded by jockey, a mobile Drosophila element related to mammalian LINEs.

The mobile element jockey is similar in structural organization and coding potential to the LINEs of various organisms. It is transcribed at different stages of Drosophila ontogenesis. The Drosophila LINE family includes active transposable elements. Current models for the mechanism of transposition involve reverse transcription of an RNA intermediate and utilization of element-encoded proteins. As demonstrated here, a 2.23 kb DNA fragment from the region of jockey encoding the putative reverse transcriptase was stably introduced into an expression system under inducible control of the Escherichia coli lac regulatory elements. We describe the expression of the 92 kDa protein and identify this polypeptide alone as the authentic jockey reverse transcriptase based on some of its physical and enzymic properties. The jockey polymerase demonstrates RNA and DNA-directed DNA polymerase activities but lacks detectable RNase H, has a temperature optimum at 26 degrees C, requires Mg2+ or Mn2+ as a cofactor and is inactivated by sulphydryl reagent. The enzyme prefers poly(rC) and poly(rA) as template and 'activated' DNA is not effective.

Animals↗
PubMed1991

[The isolation and characteristics of monoclonal antibodies to the HNK-1 antigen of natural killers].

Monoclonal antibodies to the HNK-1 differentiated antigen of natural killer cells have been obtained. A glycoprotein of the white human brain connected with myelin was used as an antigen for immunization of mice. The monoclonal antibodies obtained are shown to reduce the cytotoxic activity of a human blood mononuclear fraction as much as by 65% in relation to the human lymphoblastoma cell culture K-562. Their interaction with the surface antigen of mononuclears was shown by immunofluorescent method. Monoclonal antibodies belong to the class of immunoglobulins M.

Animals↗
PubMed1991

[Clinical and functional correlations of left-atrial myocardial excursions in patients with mitral valve defects (I)].

Three types of atrial excursions correlating with the somatic symptoms of circulatory and respiratory dysfunctions, as well as with the degree of left atrial dilatation were intraoperatively recorded in patients with mitral valvular disease. Types I and II excursions were more common in patients with left atrioventricular stenosis, Type III in those with mitral incompetence. It is concluded that it is advisable to use left atrial myocardial excursion characteristics in the diagnosis of cardiac disease.

Adolescent↗
PubMed1991

[The possibility of using the method of neutron activation radiography to detect micro-quantities of environmental radioactive pollutants].

A method of neutron-activation radiography was employed to investigate U distribution in leaves of plants (poplars, birches), growing in areas of mining ores with a high level of U which penetrates plants from the soil via the root system and appears on the surface of leaves, repeating their macrostructure. U also falls out on the surface of leaves in radioactive dust. The shapes of U manifestation permit the identification of its routes of penetration of the leaves of plants. Local U concentration even in an insignificant total excess of a radiation background can be considerable, leading to the destruction of tissues of plants as a result of alpha-radiation of U nuclei. A conclusion has been made of the danger of contamination of agricultural plants, growing in areas with ecological problems.

Mining↗
PubMed1990

[A method and a device for the differential diagnosis of retinal pathological states].

A new method and a device--a stimulator ophthalmological KNSO 1-88 "Phosphene" is suggested for differential diagnosis of pathologic conditions of the retina. It is shown that by means of the proposed method, after 20-25 minutes of dark adaptation the threshold of electric sensitivity by phosphene increases differently with respect to the initial level (on the first minute of dark adaptation): in norm--by 15.2%, in optic nerve atrophy--by 14%, in pigmentary and nonpigmentary forms of retinal dystrophy--by 33.2%. Thus, investigation of the threshold of electric sensitivity by phosphene presents valuable supplementary data for differential diagnosis between optic nerve atrophy and nonpigmentary form of retinal degeneration: in optic nerve atrophy the degree of the threshold increase of absolute electric sensitivity differs, as a rule, but a little from normal values, while in pigmentary and nonpigmentary forms of retinal degeneration it is 2-3 time above norm.

Adult↗
PubMed1990

[The effect of preparations of non-histone chromosomal proteins on the expression of hetero-organic membrane antigens of kidney origin in a primary rat hepatocyte culture].

The expression of membrane hetero-organic antigens of kidney origin, associated with the rat hepatomas in primary culture of intact adult rat hepatocytes, was investigated by means of the indirect immunofluorescence method using a specific immune serum. These antigens were observed on the membrane of some hepatocytes after their contact with nonhistone chromosomal proteins (NHCP), which were obtained from the kidney of intact rats from cells of hepatoma 27 and Zajdela hepatoma, or from the carcinogenic liver after a single diethylnitrosamine injection. Negative results were obtained after the incubation of hepatocytes in the medium lacking some of NHCP, or in that with NHCP obtained from the liver of intact rats.

Animals↗
PubMed1990

[The treatment of patients with chronic bronchitis and bronchial asthma].

The authors analyzed treatment results in 82 patients with chronic bronchitis and 68 patients with bronchial asthma including association of inhalation of humid and dry sodium chloride aerosols with preliminary administration of a broncholytic drug. Improvement of the patients' condition was confirmed by results of functional examinations and data of immunological tests.

Asthma↗
PubMed1990

[Various aspects of the status of humoral immunity in patients after surgical correction of rheumatic heart defects under artificial circulation].

The serum concentrations of immunoglobulins A, M, and G were studied in 70 patients with rheumatic heart diseases and in 72 patients with spontaneous and pokeweed mitogen-induced production of these immunoglobulins and mononuclear peripheral blood cells. The investigations were done before and 1-2 and 7-8 days after surgery. Some patients received myelopid in the early postoperative period in addition to the conventional methods of therapy. With high serum IgA, IgM, and IgG levels, reduced humoral immunity was noted. Within the first two days after the operation, the capability of cells to produce IgA and IgG in response to pokeweed mitogen stimulation was lost, the induced IgM production was reduced considerably, and the serum IgA and IgM levels fell significantly. Eight days after surgery, the immune response was partially recovered. Myelopid facilitates complete restoration of humoral immunity and reduces the incidence of postoperative pneumonia more than threefold.

Activins↗
PubMed1990

[Current approach to the surgical treatment of recurrent mitral valve stenosis].

In the period of 1971-1989, 266 patients with mitral restenosis were operated on: 82 closed mitral recomissurotomies and 184 operations under artificial circulation were performed. Complicated mitral diseases were found in 94% of the patients operated on. The causes of the mitral restenosis are analysed, and the features of its surgical correction together with the short- and long-term results are discussed. Comparison of the closed and open methods of the therapy for mitral stenosis showed that open-heart interventions under artificial circulation are most effective, prevent recurrences, and thus may be considered the operation of choice due to significantly lower hospital mortality rates in the recent five years.

Adolescent↗
PubMed1990

[Characteristics of immunologic homeostasis in the late period after reconstructive operations on the heart valves].

The immune status, i.e. T and B lymphocytes and their populations, was assessed after heart valve replacement or reconstruction in 70 patients with acquired heart defects. In 30%, the immune status was found to be normal which corresponded to inactive rheumatic process in these patients; 40% showed activated immunity manifested by increased T-active, T-total, T-helper, and T-suppressor numbers compared to the first group, which corresponded to activation of a rheumatic process in these patients. The rest 30% patients showed suppressed immunity, i.e. diminished subpopulations of T lymphocytes and B lymphocytes. These changes were detected in patients with circulatory insufficiency and progressive septic endocarditis. This allows for a conclusion that determination of the status of immunity and its correction are essential for cardiac surgery patients.

Aortic Valve↗