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Biomedical subjects

A V Petrov

Publications and source records attributed to A V Petrov.

At least 19 recordsLinked to original sources
PubMed2006

The risk of radiation-induced cerebrovascular disease in Chernobyl emergency workers.

The paper deals with estimating radiation risks of non-cancer diseases of the circulatory system among the Chernobyl emergency workers based on data from the Russian National Medical and Dosimetric Registry. The results for the cohort of 61,017 people observed between 1986 and 2000 are discussed. These are essentially updated results for the similar cohort that was studied by authors earlier in 1986-1996. Newly discovered is the statistically significant dose risk of ischemic heart disease [ERR Gy = 0.41, 95% CI = (0.05; 0.78)]. Confirmation is provided for the existence of significant dose risks for essential hypertension [ERR Gy = 0.36, 95% CI = (0.005; 0.71)] and cerebrovascular diseases [ERR Gy = 0.45, 95% CI = (0.11; 0.80)]. In 1996-2000, the assessed ERR Gy for cerebrovascular diseases was 0.22 with 95% CI = (-0.15; 0.58). Special consideration is given to cerebrovascular diseases in the cohort of 29,003 emergency workers who arrived in the Chernobyl zone during the first year after the accident. The statistically significant heterogeneity of the dose risk of cerebrovascular diseases is shown as a function of the duration of stay in the Chernobyl zone: ERR Gy = 0.89 for durations of less than 6 wk, and ERR Gy = 0.39 on average. The at-risk group with respect to cerebrovascular diseases are those who received external radiation doses greater than 150 mGy in less than 6 wk [RR = 1.18, 95% CI = (1.00; 1.40)]. For doses above 150 mGy, the statistically significant risk of cerebrovascular diseases as a function of averaged dose rate (mean daily dose) was observed: ERR per 100 mGy d = 2.17 with 95% CI = (0.64; 3.69). The duration of stay within the Chernobyl zone itself, regardless of the dose factor, had little influence on cerebrovascular disease morbidity: ERR wk = -0.002, with 95% CI = (-0.004; -0.001). The radiation risks in this large-scale cohort study were not adjusted for recognized risk factors such as excessive weight, hypercholesterolemia, smoking, alcohol consumption, and others.

Cerebrovascular Disorders↗
PubMed2005

[Clinical value of morphologic and functional parameters of blood mononuclear leukocytes in patients with rheumatoid arthritis].

The immunologic study of 412 patient with rheumatoid arthritis (RA) and 52 person of control group has been carried out. The correlation was established between activity of RA and increase in morphologic and functional activity of CD4+-, CD8+- and CD19+-lymphocytes, enhancement of proliferate response and ability to Fas-induced apoptosis of T-cells (r - from 0,5 to 0,81) and between the development of severe systemic complication and increase in percentage of CD8+-lymphocytes with large homogenous nucleoli (r=+0,71+/-0,08), mean diameter of CD8+-lymphocytes nucleus (r=+0,61+/-0,08) and mononuclear leukocytes proliferate response to FGA (r=+0,56+/-0,07). The step based system of assessment of cell immunity disturbances and the criteria of the evaluation of risks of the development of systemic complication in patients with RA were established on the above mentioned parameters development prognosis based on their immune parameters.

Adolescent↗
PubMed2004

[Effect of low intensity helium-neon laser and decimeter electromagnetic irradiation on functional indices of immune cells in patients with rheumatoid arthritis].

Clinical, laboratory, and immunoassay of 58 patients with rheumatoid arthritis, first and second degree of activity was carried out. Low-energy helium-neon laser exposure and decimeter electromagnetic radiation (DMEM) of peripheral blood was given along with the use of non-steroidal antiinflammatory drugs and methotrexate. Peculiarities of this magnetic-laser effect on proliferation response and apoptosis of mononuclear leucocytes in vitro and in vivo have been revealed. It was also established that the application of DMEM-therapy brought patients with RA in shorter period of time to clinical improvement evaluated by ACR criteria.

Adolescent↗
PubMed2004

[Persistence of various infective agents in blood mononuclear leukocytes in a debut of rheumatoid arthritis].

AIM: To study persistence in blood mononuclear leukocytes (ML) of Herpesviridae viruses (cytomegalovirus-CMV, herpes virus of type I and II, Epstein-Barr virus-EBV, hepatitis B and C viruses, Mycoplasma arthritidis-Ma,, Mycoplasma fermentans-Mf, Ureaplasma urealiticum-U, Chlamydia trachomatis-Ct). MATERIAL AND METHODS: 56 patients with debut of rheumatoid arthritis (RA) and 30 healthy persons were examined using methods of direct and indirect immunofluorescence, polymerase chain reaction and enzyme immunoassay. RESULTS: In patients with early RA persistence of infective agents in blood ML was found high (67.9%). Persistence of the viruses was studied for 1.5-2 years. Features of the clinical course of the disease were specified for various infective agents: seronegativeness in persistence of Ma, Mf and U, high activity and frequent development of systemic manifestations of RA in persistence of Herpesviridae viruses, rapid progression of bone destruction in persistence of Ct. CONCLUSION: Carriage of Herpesviridae was associated with high activity of inflammatory process, of chlamydia--with rapid bone destruction, of mycoplsma and ureaplasma--with unchanged rate of progression. Eradication of Herpes viruses, CMV, EBV and CT is indicated.

Adolescent↗
PubMed2003

Yeast telosome complex: components and their functions.

Telomeres are multi-component DNA-protein complexes protecting linear chromosome termini against degradation and fusion. Telomeres and their components are involved in many essential processes: control of cell division number, regulation of transcription, reparation. They are necessary for correct chromosome segregation during cell division. Telomere protein content and DNA length are under control of different factors, such as components of replication and reparation machinery and cell division cycle kinases. Here we discuss the participation of components of yeast telomere (telosome complex) in different cellular processes, telomeric DNA length regulation pathways, and some issues of telosome evolution.

DNA, Fungal↗
PubMed2002

Thyroid cancer incidence among liquidators of the Chernobyl accident. Absence of dependence of radiation risks on external radiation dose.

The increase of thyroid cancer incidence rate among children living in the Chernobyl contaminated territories of Belarus, Russia and Ukraine has widely been accepted. Our current work deals with thyroid cancer incidence in the cohort of liquidators (99024 persons) living in 6 regions of Russia: North-West, Volgo-Vyatsky, Central-Chernozemny, Povolzhsky, North-Caucasus and Urals. In the period 1986-1998, a total of 58 thyroid cancer cases were detected in this cohort. We found a statistically significant increase of the thyroid cancer incidence rate in liquidators as compared to the baseline (male population of Russia) level (SIR=4.33, 95% CI: 3.29; 5.60). It was demonstrated that there is no dependence of incidence rates due to external radiation exposure (ERR/Gy=-2.23, 95% CI: -4.67; 0.22).

Adolescent↗
PubMed2002

[Spontaneous and Fas-induced apoptosis of mononuclear leukocytes in rheumatoid arthritis].

A study was made into the ability of mononuclear leukocytes recovered from blood of 77 patients with rheumatiod arthritis (RA), 17 patients with osteoarthrosis deformans (OAD), 18 patients with Chlamydia-associated reactive arthritis (ReA), and 20 healthy controls, to precipitate spontaneous and Fas-induced apoptosis. RA patients versus healthy persons and patients with OAD and ReA displayed lower parameters characterizing spontaneous and Fas-induced apoptosis. A correlation was established between the ability of T- and B-lymphocytes to usher in Fas-induced apoptosis during incubation with RhHA and KonA and degree of RA activity.

Antibodies, Monoclonal↗
PubMed2001

A specific DNA-dependent DNA polymerase is associated with Saccharomyces cerevisiae telomerase.

The telomere DNA of most eucaryotes consists of tandem DNA repeats and a number of associated proteins. The synthesis of the G-rich DNA strand is performed by the telomerase complex. The complementary C-strand is synthesized by DNA-dependent DNA polymerases. Using telomerase reverse transcriptase tagging followed by immunoprecipitation coupled with two-step purification, we have found a specific DNA-dependent DNA polymerase activity associated with telomerase of Saccharomyces cerevisiae. Investigation of the biochemical properties of this DNA polymerase activity confirms the hypothesis of tight interaction of DNA polymerase delta with telomerase.

Affinity Labels↗
PubMed2000

Radiation-epidemiological analysis of incidence of non-cancer diseases among the Chernobyl liquidators.

The work is concerned with assessment of radiation risks for non-cancer disease among the Chernobyl liquidators from 1986 to 1996. As of 1 January 1999, the Russian National Medical and Dosimetric Registry contains medical and dosimetric data for 174,000 liquidators. The cohort of 68,309 liquidators for whom best verified medical data are available is discussed. The dose dependency of incidence of non-cancer diseases was estimated by the cohort method and using the software package Epicure. For some classes of non-cancer diseases among liquidators, statistically significant estimates of radiation risk were derived for the first time. The highest excess relative risk per 1 Gy was found for cerebrovascular diseases; ERR Gy(-1)=1.17 at the 95% confidence interval (0.45; 1.88).

Adolescent↗
PubMed2000

[Circadian rhythms of hypophysis-thyroid hormones secretion in patients with bronchial asthma].

AIM: To examine circadian rhythms of hypophysiothyroid system in patients with bronchial asthma and effects of exogenic glucocorticoids on thyroid function. MATERIALS AND METHODS: Free T3, T4 and TTH were measured in plasma using immunochemiluminescence in 16 patients with nonallergic bronchial asthma running a severe course. The plasma samples were taken each 6 hours for 48 hours. RESULTS: In patients with severe bronchial asthma (SBA) thyroid functional activity changed. Production of T3 increased while that of T4 dropped at night. TTH concentration rhythm for 24 hours was like that in healthy subjects. Glucocorticoids induced no significant changes in circadian rhythms of hypophysiothyroid system in SBA patients. CONCLUSION: In SBA functional activity of the hypophysiothyroid system changes with rearrangement of hormonal production at night.

Adult↗
PubMed1998

Telomerase from Saccharomyces cerevisiae contains several protein subunits and may have different activities depending on the protein content.

Telomerase is a ribonucleoprotein responsible for maintaining telomeres during the cell cycle [1,2]. Here we describe a two-step purification procedure for the Saccharomyces cerevisiae telomerase complex. We have found that the properties (processivity, nuclease activity) of telomerase depend on the isolation procedure. Using a cross-linking approach, we have revealed several proteins that could be components of the telomerase complex. Furthermore, spectra of cross-linked proteins differ in processive and non-processive telomerase complexes.

Antisense Elements (Genetics)↗
PubMed1998

[The use of electrophoretic methods for determining modified proteins in diabetic patients].

Modified proteins were determined by isoelectric focusing in borate-polyol system with subsequent colorimetry (micromethod) and electrophoresis of blood serum on paper with subsequent TCA-ethanol treatment. Increased levels of glycated hemoglobin and modified albumin and changed light absorbance of glycated albumin were detected. The levels of glycated hemoglobin assessed by the micromethod and colorimetry without calibration did not correlate.

Blood Protein Electrophoresis↗
PubMed1997

Telomerase is an unusual RNA-containing enzyme. A review.

Telomeres, the natural ends of linear eukaryotic chromosomes, are essential for protecting chromosomes from degradation and fusion. The synthesis of telomere DNA repeats in most eukaryotes is performed by a special enzyme, telomerase. Telomerase, a ribonucleoprotein enzyme, is a specialized reverse transcriptase utilizing its RNA moiety as a template for synthesis of telomeric DNA. Enzymatic properties and results of comparative analysis of telomerase RNA and protein structures from different eukaryotic systems are discussed in this review.

Animals↗
PubMed1993

[Drug and non-drug immunocorrection in peptic ulcer].

Drug immunocorrection and microwave resonance therapy allowed to normalize the immune status in 93% of patients with ulcer disease. This allowed to achieve clinico-endoscopic remission in 82%, reduce scarring time on the average by 6-7 days and to reduce markedly the recurrence frequency.

Acupuncture Points↗
PubMed1990

[Diagnosis and treatment of tumors of the small intestine].

The authors studied the results of preoperative diagnosis of tumors of the small intestine and the late-term results of operative treatment of malignant new growth in 25 patients. It is shown that the X-ray method allows tumors to be detected in some cases but its possibilities are limited. Signs of ileus prevail in the clinical picture in malignant tumors, while signs of intestinal bleeding prevail in benign tumors. Resection of the intestine with the tumor and regional lymph nodes in sarcomas produces satisfactory results in some cases.

Female↗
PubMed1989

Hippocampal synaptic plasticity induced by excitatory amino acids includes changes in sensitivity to the calcium channel blocker, omega-conotoxin.

The hippocampus is widely used in investigations of different forms of synaptic plasticity, including long-term potentiation and kindling. Receptors for excitatory amino acids (EAAs) play a prominent role in these phenomena. Recently, is has been demonstrated that exposure of hippocampal slices to EAAs and related agonists produces biphasic effects on excitatory synaptic transmission: initial blockade of synaptic responses is followed by a delayed recovery. The recovered responses demonstrate altered pharmacological properties: they acquire sensitivity to N-methyl-D-aspartate (NMDA) antagonists during L-glutamate (Glu) exposure and lose sensitivity to both NMDA and non-NMDA antagonists under L-aspartate (Asp). These changes persist for many hours. It was suggested that this form of hippocampal plasticity may involve transitions between distinct states of synaptic functioning. To explore this possibility, we investigated several properties of synaptic transmission in the initial and EAA-modified states. Here we report that hippocampal postsynaptic potentials (PSPs) evoked under Glu or Asp exposure completely lose sensitivity to omega-conotoxin GVIA (omega-CgTX), a potent, specific, and irreversible blocker of certain types of neuronal calcium channels. After washout of the EAA, sensitivity to the toxin is regained. These results indicate that prolonged EAA exposure induces profound changes in the machinery of synaptic transmission, which include, but are not limited to, changes in calcium channel functioning.

Amino Acids↗
PubMed1989

[Glycosylated hemoglobin (HbA1c) in blood in impaired tolerance to glucose and sugar diabetes].

Isoelectric focussing in borate-poliol system is employed for measuring the blood glycosylated hemoglobin (HbA1c) levels at the treatment and prophylaxis institutions in Yalta. Examinations of normal subjects and patients with disordered glucose tolerance and apparent diabetes mellitus have revealed a significant elevation of HbA1c level in the patients with impaired glucose tolerance vs. normal subjects; these levels have been virtually the same in the diabetics and patients with impaired glucose tolerance. Over the course of health resort treatment the diabetics develop negligible changes in the HbA1c levels, paralleled by a significant reduction of glycemia on an empty stomach.

Diabetes Mellitus↗