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Biomedical subjects

N V Orlova

Publications and source records attributed to N V Orlova.

At least 19 recordsLinked to original sources
PubMed2006

[Mechanism of protective effect of amphiphilic compounds during hypertonic hemolysis of erythrocytes].

Antihemolytic effect of various amphiphilic compounds under conditions of red blood cell hypertonic hemolysis at different temperatures (0 and 37 degrees C) and cell exposure to diamide was investigated. The level of maximum antihemolytic activity and values of efficient concentrations for all studied substances were lower at 0 degrees C if compared with 37 degrees C. Exposure of erythrocytes to diamide (5 and 10 mmol/l) did not change cell sensibility to hypertonic medium. There has been demonstrated a temperature-dependent decrease in the efficiency of studiedsubstances under hypertonic hemolysis of erythrocytes exposed to 10 mmol/l diamide. Found reduction in efficiency of amphiphiles at low temperature and at high concentration of diamide was probably caused by similar changes of structural and dynamic state of erythrocyte membrane.

Cell Culture Techniques↗
PubMed2003

The use of thermal lensing for the determination of pyrogens.

Based on the optimized spectrophotometric determination of pyrogens (of various classes ( p-aminophenol and endotoxins), thermal lensing was applied to the determination of these substances at the submicrogram level. The limit of detection of p-aminophenol, a pyrogenic impurity in pharmaceutical formulations of paracetamol, by reaction with resorcinol in alkaline solutions is 100 ng mL(-1). Phloroglucinol was considered as an analog of resorcinol as a reagent in this reaction. The conditions of spectrophotometric determination of pyrogenic lipopolysaccharides (endotoxins) by ion-pair formation with methylene blue (the limit of detection is 100 ng mL(-1)), by ion-pair formation with Stains-All (1-ethyl-2-[3-(1-ethylnaphtho[1,2-d]thiazolin-2-ylidene)-2-methylpropenyl]naphtho[1,2-d]thiazolium bromide) (the limit of detection is 500 ng mL(-1)), and by reaction of 2-keto-3-deoxyoctonic acid with thiobarbituric acid (the limit of detection is 800 ng mL(-1)) were proposed. The optimized procedure for 2-keto-3-deoxyoctonic acid was applied for thermal lensing that provided a decrease in the limit of detection to 70 ng mL(-1) and was also used for lipopolysaccharide determination in the endotoxin standard from E. coli.

Acetaminophen↗
PubMed2002

[Use of thymodepressin for treating autoimmune cytopenia].

AIM: To study influence of thymodepressin on the course of autoimmune cytopenia. MATERIAL AND METHODS: Thymodepressin is a new synthetic hemoregulatory dipeptide (gamma-D-Glu-D-Trp). It was used for the treatment of 22 patients with autoimmune cytopenia. RESULTS: Hemoglobin levels were elevated in autoimmune hemolytic anemia and platelet levels were high in idiopathic thrombocytopenic purpura. A thymodepressin course resulted in a fall of total lymphocyte count and activated CD3+CD69+ lymphocytes. CONCLUSION: The above results, safety, absence of toxicity and allergenicity, parenteral and intranasal useability open perspectives for further studies of therapeutic action of thymodepressin as an immunodepressant in autoimmune processes.

Adult↗
PubMed2000

Haloperidol catalepsy consolidation in the rat as a model of neuromodulatory integration.

Haloperidol, a non-selective D(2) dopamine antagonist, both in vitro (1 microM) and in vivo (2.5 mg/kg i.p.), induced a long-term potentiation of K(+)-induced Ca(2+)-dependent release of endogenous noradrenaline and dopamine in rat brain cortical slices, by increasing the content of noradrenaline and dopamine known to be controlled by dopamine auto- and heteroreceptors. Haloperidol administration (2.5 mg/kg i.p.) evoked catalepsy and increased the content of noradrenaline and dopamine in the same structures of the brain. Haloperidol catalepsy consolidated without any additional learning and could be retrieved up to two weeks later by placing the animals in the test box. The catalepsy is disordered and retrieved only in the test box. The catalepsy was more intense on day 14 than on day 7. Injection of haloperidol immediately after conditioning evened the reflex retrieval on the following days. Moreover, learning increased the intensity of catalepsy in animals tested on the day of injection. Repeated testing of the reflex on the following days led to specific modifications of catalepsy retrieval. Pre-conditioned rats exhibited maximal catalepsy when tested immediately after being placed in the test box. These results suggest that both the processes of long-term potentiation and catalepsy consolidation are mediated by the same type of receptors, long-term modulation-inducing receptors. Endogenous neuromodulators, acting non-specifically or diffusely via their respective long-term modulation-inducing receptors, can initiate and consolidate generalized states which form the basis for emotional and motivational states.

Animals↗
PubMed2000

Determination of somatic mutant frequencies at glycophorin A and T-cell receptor loci for biodosimetry of acute and prolonged irradiation.

Somatic mutant frequencies at glycophorin A (GPA) and T-cell receptor (TCR) loci were assessed. The dependence of the GPA mutant frequency on doses of acute and prolonged irradiation was shown. In the case of acute irradiation the GPA mutant frequency displayed a three-fold greater dose-related increase as compared to prolonged irradiation. A dose-dependent increase in the TCR variant frequency was found only in a group of subjects with recent exposures. In Chernobyl clean-up workers the TCR mutant frequency was significantly higher than in control non-irradiated individuals.

Case-Control Studies↗
PubMed2000

[Pharmacological reminder of the emotional condition facilitates the amnestic memory trace retrieval].

Passive avoidance reflex was shown to be differently reproduced in rats. The reproduction was more stable in rats with a higher level of learning. Amnestic effects induced seizures were shown to depend on relationships between the intensity of learning and the intensity of seizures. Unconditioned stimuli acting as a reminder decreased the amnestic effects of seizures. Learning process significantly reduced the seizure severity. A dissociated convulsive state was reproduced with the aid of a pharmacological reminder of anxiety formed in the course of learning. Haloperidol produced anxiety and suppressed amnestic effects of seizures, facilitated conditioning in rats with a low level of learning.

Animals↗
PubMed1999

[A noninvasive approach to studying fetal cells for prenatal diagnosis of chromosomal aneuploidies].

Fetal cells isolated from maternal peripheral blood during the second trimester of pregnancy were analyzed. Blood samples were centrifuged in a Ficoll-Paque gradient, the mononuclear cell fraction was isolated and stained with fluorescent monoclonal antibodies against glycophorine A (GPA + PE), transferrin (CD71 + FITC), and Hoechst 33342. Fluorescence-activated cell sorting (FACS) was conducted on a Vantage flow cytofluorimeter (Becton Dickinson). Fluorescence in situ hybridization (FISH) with Y chromosome-specific DNA probe revealed fetal cells that exhibited Y signal in all 20 blood samples obtained from women pregnant with healthy male fetuses. The concentration of these fetal cells averaged about 1.34% and ranged from 0.1 to 4.2% in different blood samples. In six cases, blood samples were obtained from pregnant women, in which prenatal cytogenetic analysis revealed various fetal aneuploidies. Using FISH with DNA probes specific for chromosomes X, 18, and 13/21, Fetal cells with chromosomal aberrations were detected in these six maternal blood samples at a concentration from 1.5 to 5.6% (on average 3.7%). These results indicate the possibility of a new noninvasive approach, which is safe for both mother and fetus when used for isolation of fetal cells from pregnant women's blood samples and prenatal diagnosis of a broad spectrum of fetal cell chromosomal aberrations.

Aneuploidy↗
PubMed1998

Determination of somatic mutant frequencies at glycophorin A and T-cell receptor loci for biodosimetry of prolonged irradiation.

PURPOSE: To determine the variant frequencies (VF) at glycophorin A (GPA) and T-cell receptor (TCR) loci in persons exposed to prolonged ionizing radiation at different doses and to assess the significance of the GPA and TCR assays for biodosimetry of prolonged irradiation. MATERIALS AND METHODS: The VF values were determined by means of flow cytometry in 120 persons exposed between 1968-1996. Most exposures were in Chernobyl clean-up workers in 1986-1987. RESULTS: A significant correlation was shown between the NO GPA variant cell frequency and dose (r = 0.61, p < 0.0001). The slope of the linear regression was 6.3 x 10(-6) NO mutant cells/Gy. Dose-dependent increase in the TCR VF was found in the group with recent exposures (slope 2.1 x 10(-4) variant cells/Gy, r = 0.75, p = 0.0002). In the Chernobyl clean up workers who received doses less than 0.25 Gy the TCR VF unlike the GPA VF was significantly higher than in the control non-irradiated individuals (p < 0.01 and p > 0.05 respectively). CONCLUSIONS: The GPA assay has limited potential to be used as a biodosimeter of prolonged irradiation, at least in dose interval up to 2.0 Gy. The TCR assay is likely to have greater potential in estimation of recent radiation exposure than the GPA assay.

Adult↗
PubMed1990

[Clinical and prognostic value of monitoring the acute phase protein levels in patients with myocardial infarction].

The value of evaluating the protein levels at the acute stage was examined to define the clinical course and prognosis of myocardial infarction. The time course of hospital myocardial infarction was studied in 117 patients. The Manchini radial immunodiffusion with reference monospecific antisera was employed to determine individual proteins during the acute stage (orosomucoid, C-reactive protein, alpha 1-antitrypsin, C3 complement, ceruloplasmin). The level of circulating immune complexes was measured by polyethylene glycol precipitation. There was a close correlation between the circulating immune complex levels and some acute phase parameters, suggesting the relationship between immune and inflammatory processes. The changes in the magnitude of some acute phase parameters and circulating immune complexes were found to be significant in predicting the development of complications and the fatal outcome of the disease.

Acute-Phase Proteins↗
PubMed1989

[Evolution of rheumatism in children during the past 30 years].

Based on the clinical, laboratory and instrumental studies made at the Cardiorheumatologic Department of the K.A. Rauchfuss City Child's Hospital in Leningrad the authors describe evolution shown by rheumatic fever in children over the recent 30 years. In their opinion, the cases of so-called classical rheumatic fever with moderate and maximal activity of the inflammatory process occurred more frequently over the recent years. In spite of this fact rheumatic fever in children is characterized today by the decreased number of relapses and by the reduced incidence of heart disease. Attention is drawn to the circumstance that over the recent years the pediatricians tend towards the underdiagnosis of rheumatic fever.

Adolescent↗
PubMed1987

[Changes in the content of water-soluble brain proteins-antigens during bilateral avoidance training of rats].

The levels of water-soluble brain antigens have been studied during bilateral avoidance learning in Wistar rats. With the help of cross and rocket immunoelectrophoresis the content of antigens was measured in the brain structures an hour and a week after training. It was shown that the content of one of six antigens in the auditory cortex correlated with the number of tone-shock combinations. The antigen was not found in the liver and its amount was higher in the brain stem, as compared to cerebral cortex and cerebellum. The results suggest that this antigen may be involved in the processes of memory build-up.

Acoustic Stimulation↗