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Biomedical subjects

A V Volkov

Publications and source records attributed to A V Volkov.

At least 19 recordsLinked to original sources

[Soluble CD40 ligand in systemic lupus erythematosus and antiphospholipid syndrome].

AIM: To investigate a clinical role of soluble (s) CD40 ligand in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). MATERIAL AND METHODS: A serum concentration of sCD40 ligand was measured with enzyme immunoassay (Bender Medsystems, Austria) in 21 patients with primary antiphospholipid syndrome (PAPS), in 25 patients with secondary APS (SAPS) associated with SLE, in 92 SLE patients and in 16 healthy donors. RESULTS: A sCD40 ligand concentration in sera of SAPS and SLE patients was significantly higher than in donors. Significant differences by the ligand level between the above patients were not seen. In PAPS sCD40 ligand concentration was normal. Elevated serum concentration of the ligand was observed in 9.5% patients with PAPS, 54.0%--with SAPS, 73.9%--with SLE. This rise in SLE and SAPS was not related with the disease activity or renal damage. Hyperexpression of the ligand in APS was associated neither with thromboses nor with a high concentration of IgG/IgM antibodies to cardiolipin. A direct correlation occurred between sCD40 ligand level and platelet count. In SLE and SAPS elevation of the ligand level correlated with increased thickness of carotid artery intima-media complex, hypercholesterinemia and diastolic dysfunction of left ventricular myocardium. CONCLUSION: Hyperexpression of sCD40L in SLE and SAPS is associated with developing cardiovascular diseases and atherosclerosis.

Adult↗

[Molecular biology investigation of respiratory viruses as a factor of infectious complications in hemoblastosis and myelodepression].

Communicable respiratory viruses as a causative factor of infectious complication in hemoblastosis and myelodepression were investigated in 51 patients (aplastic anemia--3, multiple myeloma--10, different patterns of acute leukemia--16, chronic leukemia--8 and non-Hodgkin's lymphoma--14). Our clinical evidence obtained with the aid of polymerase chain reaction featured genomes of adenoviruses, influenza A and B viruses, respiratory-scintillating virus and coronaviruses. On the whole, respiratory viral infections were detected in 27 (52.9%) patients: adenoviruses--23.5%, coronaviruses--13.7%, influenza A and B--5.9% and respiratory-scintillating virus--3.9%. In many cases, herpes was associated with viral respiratory infection. That pathology was most often triggered by severe neutropenia induced by chemotherapy.

Adenoviridae↗

Ca(2+) transport into sarcoplasmic reticulum and immediate-early response proteins in the myocardium of rats resuscitated after systemic circulatory arrest.

Activity of antioxidant defense enzymes and content of stress protein HSP70 in the heart increased in passive and, to a lesser extent, in active rats on day 7 of the postresuscitation period after systemic circulatory arrest. The resistance of membrane structures in the heart to endogenous damaging factors in passive rats was lower than in active animals. The degree of compensation in active rats was much higher than in passive animals at these terms of the postresuscitation period.

Animals↗

[Use of metformin (siofor) in patients with gout and insulin resistance (pilot 6-month results)].

AIM: To evaluate metformin efficacy and safety in patients with gout and insulin resistance (IR). MATERIAL AND METHODS: The trial included 26 patients with gout (criteria of the American collage of rheumatologists) and IR (index HOMA). The inclusion criteria were the following: absence of antigout therapy, normal hepatic and renal function, rejection of alcohol. The drug dose was 1500 mg/day. The study was made of anthropometric and clinical characteristics, 24-h blood pressure monitoring, blood tests for uric acid, glucose, insulin, urea, creatinin, alaninaminotransferase, aspartataminotransferase, lipid spectrum at the first and further visits. RESULTS: A 6-month metformin therapy significantly changed the levels of glucose, insulin, HDLP and LDLP cholesterol, uric acid, HOMA index. Normouricemia was achieved in 11 patients, a significant lowering of uric acid--in 12 patients. The number of affected joints in 23 patients reduced from 4 (1-5) to 1 (0-2), p < 0.01. Seven patients with achieved normouricemia had no arthritis attacks. In 3 of 10 patients with chronic arthritis joint inflammation persisted. Six patients had dyspepsia during the first week of therapy, 1 patient discontinued the drug because of persistent diarrhea. CONCLUSION: Metformin therapy is safe. It reduces IR. The principal result of the study was lowering of uric acid and attenuation of the articular syndrome.

Adult↗

Mechanism of the effect of postresuscitation changes in the brain on the dynamics of extinction of orientation and exploratory response in rats.

The type of open-field behavior (determined in preliminary tests) was preserved after 10-min circulatory arrest. Postresuscitation changes in the bran modified orientation and exploratory activity under conditions of its partial extinction before clinical death. High behavioral activity of rats in the first open-field session after resuscitation was related to the impairment of memory traces, while that in the follow-up period was associated with the formation of a pathological self-maintaining system between components of orientation and exploratory behavior.

Animals↗

[Characteristics of clinical symptoms and course of systemic scleroderma depending on sex and age of onset].

AIM: To define clinical features of systemic sclerosis (SS) in age and sex aspects. MATERIAL AND METHODS: The study covered 100 patients aged 15 to 83 years with SS (24 males and 76 females) lasting for 1-15 years (mean 6.2 +/- 4.1 years). Groups of females and males, with disease onset age under 50 years (32 years) and over 50 years were compared. RESULTS: Males had a prevalent diffuse clinical form of SS with advanced skin syndrome, primarily indurative alterations, marked disturbances of microcirculation, abnormal heart rhythm and conduction, interstitial pulmonary fibrosis with development of pulmonary hypertension. The patients with late SS onset are characterized by development of visceral pathology within the first 3 years of the disease. CONCLUSION: In making SS diagnosis and in the disease treatment it is necessary to consider the patients' sex and age, peculiarities of the debut, clinical picture, course and prognosis.

Adolescent↗

Postresuscitation recovery of functional activity of central nervous system in rats during combination treatment with mexidol and neuropeptides delta sleep-inducing peptide and oxytocin.

In experiments on rats we studied the effects of antioxidant and membrane-protecting agent mexidol and neuropeptides delta sleep-inducing peptide and oxytocin administered during resuscitation after 12-min clinical death. Individual and combination treatment with these substances accelerated recovery of the neurological status and partially or completely corrected behavioral disorders associated with changes in the emotional and motivational status. Combined administration of mexidol and oxytocin most significantly promoted postresuscitation recovery of functional activity in the central nervous system.

Animals↗

Localization of cold shock proteins to cytosolic spaces surrounding nucleoids in Bacillus subtilis depends on active transcription.

Using immunofluorescence microscopy and a fusion of a cold shock protein (CSP), CspB, to green fluorescent protein (GFP), we showed that in growing cells Bacillus subtilis CSPs specifically localize to cytosolic regions surrounding the nucleoid. The subcellular localization of CSPs is influenced by the structure of the nucleoid. Decondensed chromosomes in smc mutant cells reduced the sizes of the regions in which CSPs localized, while cold shock-induced chromosome compaction was accompanied by an expansion of the space in which CSPs were present. As a control, histone-like protein HBsu localized to the nucleoids, while beta-galactosidase and GFP were detectable throughout the cell. After inhibition of translation, CspB-GFP was still present around the nucleoids in a manner similar to that in cold-shocked cells. However, in stationary-phase cells and after inhibition of transcription, CspB was distributed throughout the cell, indicating that specific localization of CspB depends on active transcription and is not due to simple exclusion from the nucleoid. Furthermore, we observed that nucleoids are more condensed and frequently abnormal in cspB cspC and cspB cspD double-mutant cells. This suggests that the function of CSPs affects chromosome structure, probably through coupling of transcription to translation, which is thought to decondense nucleoids. In addition, we found that cspB cspD and cspB cspC double mutants are defective in sporulation, with a block at or before stage 0. Interestingly, CspB and CspC are depleted from the forespore compartment but not from the mother cell. In toto, our findings suggest that CSPs localize to zones of newly synthesized RNA, coupling transcription with initiation of translation.

Bacillus subtilis↗

Decreased tolerance to acoustic stress in late postresuscitation period in Krushinsky-Molodkina rats.

The effect of circulation arrest on the development of stress-induced injuries was studied in Krushinsky-Molodkina rats genetically predisposed to audiogenic seizure. Resuscitated rats were subjected to acoustic stress 1.5 month after circulation arrest. The severity of neurological disorders and the frequency and severity of intracranial hemorrhages increased, while excitability of the central nervous system remained unchanged during stress. Thus, the resistance to stress considerably decreased in rats survived a short-term circulatory arrest due to dysfunction of the autonomic nervous regulation of hemodynamics rather than enhanced excitability of the central nervous system.

Acoustic Stimulation↗

Prophylaxis of encephalopathies and risk factors of atherogenesis development in the postresuscitation period in rats by means of succinic acid.

The effect of oral administration of succinic acid was studied in 66 rats exposed to 10 min cardiac arrest with further resuscitation. A total of 30 mg/kg of the drug were administered daily for 5 days starting with day 3 up to day 7 after resuscitation. The experiments have revealed that treatment with succinic acid caused normalization of the orienting behavior in an 'open field' test, decrease of the intensity of response to electric shock, normalization of free radical formation in the brain and serum and reduced cerebral morphological changes. The succinic acid prevented the increase of cholesterol, triglyceride and low density lipoproteins in the blood. The data suggested that after additional trials the succinic acid could be used to prevent development of postresuscitation encephalopathies (3 months after reanimation).

Animals↗

Cardiac arrest induces decrease of nitric oxide synthase activity and increase of free radical generation in rat brain regions.

Rats were subjected to 15 min cardiac arrest and sacrificed 1 h or 15-20 days after resuscitation. Homogenates of brain regions were assayed for nitric oxide synthase (NOS) activity (by measuring the mononitrosyl iron complex of NO with diethyl dithiocarbamate and endogenous brain Fe2+ using electron spin resonance spectroscopy) and generation of free radicals (FRG; by measuring H2O2-induced, luminol-dependent chemiluminescence). Cardiac arrest induced marked decrease of NOS activity and the increase of FRG, most prominent in cerebellum and less marked in cerebral cortex. Two groups of rats were revealed 15-20 days after cardiac arrest: with NOS activity significantly lower than control and not different from control. Positive linear inter-regional cross-correlations of both NOS activity and FRG (except of the group 1 h after resuscitation) as well as negative correlations between NOS and FRG were demonstrated.

Animals↗

[Role of initial hemodynamic status and rate of blood loss replacement in postresuscitation changes in blood circulation and animal mortality].

In 43 experiments performed on narcotized dogs after 10 min clinical death induced by exsanguination, the peculiarities of postresuscitation changes in the blood circulation associated with the initial hemodynamic status, the rate of the blood loss replacements after restoration of cardiac activity, and the use of infusion therapy by albosorb (specifically processed albumin) were studied. The effect of the initial level of stroke index (SI) on the pronouncement of postresuscitation derangements in the central hemodynamics (CHD) and on the resuscitation outcome was determined. With the initial value of SI being mean, the maintenance of a moderate blood deficit (10 to 15 ml/kg) within the first hour of restoration was accompanied by an improvement in the survival rate of the animals as compared with a rapid and complete replacement of the blood. The infusion of albumin and creation of a moderate overtransfusion by the first hour post resuscitation removed the prognostic value of the initial SI.

Animals↗