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Biomedical subjects

G A Levina

Publications and source records attributed to G A Levina.

At least 19 recordsLinked to original sources
PubMed1992

[State of coronary circulation and results of 24-hour ECG monitoring in patients with refractory angina pectoris].

The paper compares the data of selective coronary angiography and 24-hour monitoring in 39 patients with refractory angina pectoris. Transient ST-segment changes were revealed in 79% of the patients, ST-segment depression occurring in 54%, ST-segment elevation in 46%, T-wave inversion in 38%. A combination of ST-T interval changes and occurrence of ventricular premature contraction was found in a third of the examinees. There was no statistically significant correlation between the extent of major coronary lesion and the mean length of ST-segment displacements.

Adult↗
PubMed1991

[Transcutaneous transcatheter use of laser recanalization of coronary arteries in patients with ischemic heart disease].

The paper discusses the potential possibility and effectiveness of X-ray endovascular laser recanalization (ELR) of the coronary arteries in order to treat coronary atherosclerosis in patients with coronary heart disease. The intervention was performed in 4 patients (into the anterior interventricular artery in 3 and into the right coronary artery in 1). In 3 of 4 cases, X-ray ELR proved to be successful, in one case the intervention failed due to technological reasons. Recanalization of a completely occluded segment of the coronary artery with a residual stenosis of no more than 40% was observed in two cases. Laser recanalization of profound local coronary stenosis was made in the mid-third of the vessel in one case. It can be stated that X-ray ELR of the coronary artery may extend the scope of X-ray surgical therapeutical tools of the treatment of coronary atherosclerosis. At the same time, accumulation of clinical experience and further improvement of laser and laser catheter engineering are essential in defining the value and possible scope for the application of this method.

Angioplasty, Laser↗
PubMed1989

[The antigenic characteristics of Salmonella typhi L forms].

The study of the possibility of detecting the specific antigens of S. typhi L forms has revealed that out of three destructive methods under study (osmotic lysis, freezing-thawing, sonication) only ultrasonic disintegration has proved to be effective for S. typhi L forms. Three specific fractions capable of interacting only with specific antibodies to S. typhi L forms have been revealed in the course of chromatographic separation of the soluble antigenic complex of S. typhi stable L forms and the subsequent analysis of the fractions thus obtained in the enzyme immunoassay.

Antigens, Bacterial↗
PubMed1989

[The detection of antigenemia in typhoid patients at different periods in the course of the infection].

The enzyme immunoassay of serum samples, obtained from 37 typhoid patients and previously subjected to bacteriological study with negative results, permitted the detection of S. typhi specific antigens and, as a consequence, the rapid diagnosis of the disease. The prevalence of various antigenic components of S. typhi was observed at different stages of infection. The presence of surface O and Vi antigens was characteristic of acute stages of S. typhi infection. At the same time L-form antigens, in rare cases in combination with surface O and Vi antigens, were characteristic of patients at the period following the acute stage of the disease, as well as chronic carriers. This is indicative of the necessity of introducing specific antibodies to the antigenic determinants of S. typhi L forms into the assortment of diagnostic immune preparations.

Acute Disease↗
PubMed1989

[The possibilities of using variants of immunoenzyme analysis for detecting L-form Salmonella typhi bacteria in biological fluids].

The possibility of using, on principle, the enzyme immunoassay (EIA) in different modifications for the detection of S. typhi L-forms in biological fluids (blood, urine) was established. The inhibiting variant of EIA showed the highest sensitivity: 1 ng/ml. The direct sandwich variant permitted the quantitative determination of the antigen of S. typhi L-form in the widest range of 20-500 ng/ml. The indirect enzyme immunometric variant permitted the detection of S. typhi L-forms with a sensitivity of 10(5) colony-forming units per ml only in urine.

Antigens, Bacterial↗
PubMed1987

[Myocardial contractile function of the left ventricle in patients with congenital stenosis of the ostium aortae].

A study of 61 patients with congenital stenosis of the aortic ostium has shown that left ventricular myocardial dysfunction is related to the extent of myocardial hypertrophy. Progressive discrepancy between growing left ventricular myocardial hypertrophy and its blood supply resulted, at a certain point, in a qualitative change from compensatory to abnormal hypertrophy. The extent of left ventricular hypertrophy determined the severity of aortic stenosis and left ventricular dysfunction. The emergence of electrocardiographic signs of left ventricular hypertrophy and systolic overstrain is indicative of the defect acquiring a new quality--that of left ventricular and relative coronary insufficiency.

Adolescent↗
PubMed1986

[Detection of microbial variants of Salmonella typhi in the bone marrow of typhoid patients and carriers].

The immunofluorescence test with the use of antisera to S. typhi and its L-forms permits the detection of the infective agent in bone marrow smears. This diagnostic method is particularly important in cases of carrier state in the latent phase and in differential diagnosis. As revealed in this study, the microbial variants of S. typhi, reacting with antiserum to its L-forms, are present in the bone marrow of carriers. They are localized, as a rule, on the membranes of lymphoid and erythroid cells, which probably leads to the formation of rosettes.

Bone Marrow↗
PubMed1985

[Antigenic structure of Salmonella L forms studied by an immunoferritin method].

The antigenic structure of the L-forms of salmonellae (S. typhimurium and S. typhi) in comparison with that of the initial bacterial cultures and revertant cultures was studied with the use of the immunoferritin method. The L-forms of salmonellae were found to retain an insignificant amount of O-antigen, as well as to have K-antigen on the surface of the cytoplasmic membrane, but in a lesser amount than the initial strains. In the cultures reverting from the L-forms of S. typhimurium and S. typhi the quantitative and qualitative characteristics of O- and K-antigens were completely restored.

Animals↗
PubMed1985

[In vivo experimental modelling of the infectious process caused by stable L forms of the causative agent of typhoid].

To simulate the infectious process and to study the persistence of L-forms, rabbits and guinea pigs were infected with S. typhi stable L-forms. The materials presented in this work indicate that both subconjunctival and intraperitoneal infection led to the development of the clinically indistinct, but morphologically pronounced pathological process with characteristic localization and typical changes in the gastrointestinal tract. The typical features of the process were the generalized immunomorphological reaction of the lymphoid apparatus with the appearance of light-colored reticulomacrophagal elements, the signs of the activation of humoral and cell-mediated immunity and the formation of small epitheloidocellular granulomas. The results of the investigation indicate that the stable cultures of S. typhi L-forms are highly pathogenic and capable of inducing the infectious process in experimental animals.

Animals↗
PubMed1984

[Diastolic coronary gradient during Valsalva's test in patients with ischemic heart disease].

Thirty-five patients including 26 with coronary heart disease and 9 with a pain syndrome non-typical of angina were studied. All patients were subjected to Valsalva's standardized test during which the pressure was measured in the aorta and the heart left ventricle paralleled by simultaneous ECG registration at the three standard leads and at AVR lead. The test sensitivity equalled 50%, the test specificity was 88.9%. Both healthy subjects and coronary heart disease patients displayed a reduction of the diastolic coronary gradient during Valsalva's test, mostly due to the increased diastolic pressure in the left ventricle, which corresponded to the dissemination of coronary atherosclerosis (by coronographic findings). The mechanisms contributing to the development of ischemia associated with Valsalva's test include a fall in coronary perfusion, tachycardia and the reflectory influence of the pulmonary receptors.

Adult↗
PubMed1983

[Immunoelectrophoretic analysis of the antigenic composition of Salmonella typhi in the process of L transformation and reversion].

In the study of the antigenic composition of S. typhi L-forms and their revertants were determined. The stable L-forms were characterized by profound disturbances in the synthesis of Vi- and H-antigens. After reversion to bacterial forms all the revertants under study showed the complete restoration of their bacterial antigenic structure.

Antigens, Bacterial↗
PubMed1983

[Processes of bacterial L transformation and L form reversion in the body of argasid ticks].

The experimental infection of tampan ticks (Ornithodoros moubata) with the bacterial cultures of Listeria monocytogenes and Salmonella typhimurium, as well as with their L-forms, was carried out. These experiments demonstrated that both the L-transformation of bacteria and the reversion of their L-forms into the initial bacterial culture could occur in the body of the ticks.

Animals↗
PubMed1983

[Segmental contractility--criterion of the integral function of the left ventricle in patients with ischemic heart disease].

The expulsion fraction was examined with reference to qualitative and quantitative parameters of segment contractility of the left-ventricular wall in 68 coronary patients. Segment contractility of the left-ventricular wall can provide the basis for the interpretation of the left-ventricular integrative function in these patients. Its qualitative assessment can characterize the general condition of the myocardium, whereas its quantitative features may contribute to the elucidation of mechanisms involved in compensatory relationships between the damaged and intact myocardium of the left ventricle.

Adult↗