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Biomedical subjects

N A Fedorov

Publications and source records attributed to N A Fedorov.

At least 19 recordsLinked to original sources
PubMed1995

[Blood fibronectin and liver phagocytic function in peritonitis patients].

The concentration of blood fibronectin and the state of the phagocytic function in the liver was studied in 19 patients with an emergency pathology of the abdominal cavity complicated by the infective-toxin shock and polyorganic insufficiency. Patients with severe abdominal pathology had a considerably decreased level of circulating fibronectin, disturbed phagocytic function of the liver and development of the hypercatabolic state. Hypofibronectinemia was accompanied by polyorganic disorders, systemic bacteriotoxemia and disseminated intravascular coagulation. Causes of hypofibronectinemia and its role in pathogenesis of systemic complications in patients with emergency abdominal pathology are discussed.

Adult↗
PubMed1992

[The ajoene blockade of integrin-dependent processes in an HIV-infected cell system].

Ajoene, (E,Z)-4,5,9-trithiadodeca-1,6,11-triene-9-oxide, isolated from extracts of garlic (Allium sativum) has been previously shown to inhibit platelet aggregation by inactivating allosterically the platelet integrin, GP IIb/IIIa. The structural and functional similarity of integrins led the authors to suggest that ajoene may also inhibit adhesive interactions and fusion of leukocytes. Synthetic stereoisomers of ajoene synthesized by the authors exhibited equal antiaggregatory activities (IC100 approximately 50 microM for platelets; IC100 approximately 10 microM for fMLP-stimulated neutrophils). Racemic ajoene inhibited the fusion of H9 cells with HIV-infected H9:RF cells (IC50 approximately 45 microM; 16 h of incubation) and also exhibited a degree of antiviral activity (IC50 approximately 5 microM as assessed by inhibition of HIV-1/CEM/Lav 1 Bru replication in CEM13 cells; m. o. i. 0.1; 72 h). A considerable increase in the latter became evident when the compound was administered in aliquots of 50 microM per 12 h of incubation (inhibition by 30%; total concentration 0.25 microM; 72 h).(ABSTRACT TRUNCATED AT 250 WORDS)

Antiviral Agents↗
PubMed1991

The role of adhesive interactions and extracellular matrix fibronectin from human polymorphonuclear leukocytes in the respiratory burst.

The Arg-Gly-Asp (RGD) tripeptide and ajoene were used for studying the role of adhesive receptors in the respiratory burst. Activation of the respiratory burst was examined by using luminol-dependent and lucigenin-dependent chemiluminescence. Recently, it was shown that ajoene, (E, Z)-4,5,9-trithiadodeca-1,6,11-trien-9-oxide, a substance isolated from garlic extract, inhibits the binding of fibrinogen to activated platelets by direct interaction with fibrinogen receptor (Apitz-Castro, R., Lederma, E., Escalante, J. and Jain, M.K. (1986) Biochem. Biophys. Res. Commun. 141, 145-150). Taking into consideration the structural and functional similarity of integrins, it would be reasonable to assume that ajoene as well as RGD can inhibit adhesive interactions of human neutrophils. We have shown that the effect of various activators on the respiratory burst was abolished by ajoene or RGD treatment. The inhibitory effect of RGD and ajoene was dose-dependent. The treatment of neutrophils with antiserum against human plasma fibronectin inhibited the respiratory burst in response to formyl-methionyl-leucylphenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA). This effect is dose-dependent and reversible with the addition of fibronectin. These data indicate that the respiratory burst in human neutrophils is mediated by the integrin family of receptors and that interactions between the extracellular matrix fibronectin and cells are necessary for the respiratory burst.

Adult↗
PubMed1991

[Physiological variants of functional and biochemical indicators of thrombocytes].

The reported data of the latest 5-7 years point to a high reactivity of human and animal blood platelets depending on the physiological status (age, sex, season, time of the day, diet, physical and psychoemotional tension and so forth) and in disease (cardiovascular diseases, intoxication and others). In view of this fact platelets (in physiology and pathology) may serve as a highly sensitive and convenient test system not only for hemostatic blood potential estimation but also for the determination of physiological and pathological shifts in other systems of the body.

Adenine Nucleotides↗
PubMed1991

[Functional activity of thrombocytes and granulocytes of donor blood after selective removal of fibronectin].

Storage of anticoagulated whole blood leads to the activation of platelets and granulocytes, formation of aggregates, lysis of cells, various thrombogenic substances, including proteolytic enzymes. Transfusion of the blood may cause capillary occlusion, intravascular coagulation, renal and hepatic dysfunction. Gel-silicagel affinity+ chromatography of the anticoagulated whole blood was shown to result in selective sorption of plasma fibrin. Preactivated platelets and granulocytes were also removed by interaction of cell fibronectin receptors with immobilized fibronectin. The residual platelets and granulocytes lost their ability to storage-induced activation and remained viable for at least 48 hours at 4 degrees C.

Blood Donors↗
PubMed1991

[Plasma fibronectin level in patients with chronic diseases of the liver].

The diagnostic value of determination of plasma fibronectin in chronic hepatic diseases was examined on the basis of the data available in the literature and the authors' own results of studies. The procedure for measuring fibronectin in healthy subjects and patients with hepatic cirrhoses and chronic persistent hepatitis is briefly outlined. Possible mechanisms of fibronectin level alterations are discussed in these pathological processes.

Adolescent↗
PubMed1990

[Treatment of threatened preterm labor with partusisten and salbupart].

Comparative trials of two tocolytic preparations, salbupart (Polfa) and partusisten, showed their high efficacy (75 and 80 per cent, respectively). The success of management depends on the outcome of the preceding pregnancies, the course of current pregnancy in the 1st and 2nd trimesters, the cervical status, and extent of therapy. Normalization of cAMP levels concurrent with reduced force of uterine contractions and elimination of clinical signs of threatening pregnancy termination are also indicative of benefits of tocolytic therapy.

Albuterol↗
PubMed1990

[Isolation, identification and electrophoretic properties of DNA excreted by human lymphocytes].

It was shown that the buoyant density of DNA isolated from lymphocyte incubation media as well as from blood plasma of healthy patients and patients with chronic lympholeukemia (CLL) using the SDS-phenol method with subsequent ultracentrifugation in a cesium trifluoroacetate density gradient is 1.59-1.60 and 1.60-1.63 g/ml, respectively. Using electrophoresis in 0.6% agarose gel, it was found that the DNA excreted by lymphocytes from healthy patients and CLL patients is a high molecular weight fraction comprising 21,000 nucleotide pairs. This DNA fragment contains 90-95% of [3H]thymidine used for the labeling of DNA excreted by lymphocytes from healthy patients and patients with CLL. No traces of [3H]thymidine were found in the middle part of the agarose gel containing the diffuse material bound to ethidium bromide.

DNA↗
PubMed1989

[Determination of the luminol-dependent chemiluminescence of granulocytes].

The authors have defined the optimal conditions for the determination of granulocyte luminol-dependent chemiluminescence (LDCL) in normal donors; the granulocytes have been isolated from small volumes of blood. Granulocytic LDCL has been studied in granulocyte exposure to zymosan, zymosan-activated serum, phorbol-myristate acetate, and FMLP (formyl-L-methionyl-leucyl-phenylalanine) synthetic tripeptide. Significant individual differences in the granulocyte activities in normal subjects have been revealed.

Granulocytes↗