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At least 145 records · Page 8Linked to original sources
PubMed2004

Effect of cytosine arabinoside and hydroxyurea on micronucleus formation induced by model clastogens in Chinese hamster V79 cells.

Post-cultivation of treated cells in the presence of DNA repair inhibitors has been proposed as a new methodological approach of the micronucleus (MN) assay to increase the sensitivity of this technique. In order to assess the advantages and limitations of this promising methodological approach, several genotoxic/clastogenic agents with different mechanisms of activity were chosen to assess the effect of DNA repair inhibitors on the level of micronuclei (MNi) induced by particular agent using Chinese hamster V79 cells. Both UV light (UV) and benzo(a)pyrene (BaP) increased significantly the micronucleus level in V79 cells (p<0.01-0.001). In contrast, only at cytotoxic concentration (>0.8 mM) a slight but statistically significant rise of MNi was determined in cells exposed to N-methyl-N-nitroso urea (MNU). However, post-cultivation of MNU-treated cells in the presence of DNA repair inhibitors (cytosine arabinoside, AraC and hydroxyurea, HU) led to an additional rise of MNi. While AraC had a synergistic effect on MN formation (0.4 mM and 0.8 mM, DS=2.14 and 1.13, respectively), HU had less than additive effect (DS=0.86 and 0.66) and the combined treatment of cells with AraC and HU was least effective (Cf=0.36 and 0.28). On the other hand, post-cultivation of UV- and BaP-treated cells in the presence of AraC did not result in any synergistic effect on MN formation. No effect or even a decrease of MNi was measured particularly due to HU or combined treatment of HU and AraC. Incubation of control untreated cells with AraC gave rise to a significant increase of MN formation (2- to 2.5-fold) as well. Hydroxyurea or the combined treatment of HU with AraC had lower effect on the spontaneous level of MNi. Our study shows, that the combination of MNU treatment with DNA repair inhibitors increased the number of MNi on well proliferating V79 cells; in case UV light and BaP treatment, the involvement of DNA repair inhibitors did not contribute to an increase of sensitivity of MN assay. On the basis of our results we suppose that the AraC/CBMN assay might be a promising approach in genetic toxicology applied only to lymphocytes.

Animals↗
PubMed2005

Combined laser-assisted microdissection and short tandem repeat analysis for detection of in situ microchimerism after solid organ transplantation.

Following the transplantation of a solid organ leukocytes of donor origin migrate out of the organ, contributing to a chimeric blood cell population ("peripheral microchimerism"). At the same time, leukocytes and pluripotent precursor cells of the recipient migrate into the organ, creating an "in situ microchimerism." A method is described for the identification of cells with the recipient's genotype in the transplanted organ by combining laser-assisted microdissection and short tandem repeat analysis. The microdissection allows the contamination-free isolation of morphologically and immunohistochemically characterized cells or groups of cells from histological tissue sections. The subsequent analysis of highly polymorphic short tandem repeats enables unequivocal genotyping in nearly all donor-recipient instances. Employing this new methodological approach, we could identify in individual transplanted organs differentiated parenchymal cells of recipient's origin, which most probably are derived from circulating precursor cells from the bone marrow.

Humans↗
PubMedDate not supplied

[Development of forensic medical expertise of sexual conditions in men].

The necessity of new methodological approaches in forensic medical examination of sexual male conditions are discussed basing on the analysis of questionnaire surveys of isolated groups of men and forensic medical examinations of male victims accused of sexual crimes. How to update expertise of sexual male conditions including investigations of anorectal and erectile dysfunctions in shown.

Child↗
PubMed1991

[Various results of the study of medico-biological aspects of alcoholism in Siberia and Far East].

To study the dynamic changes in alcohol abuse, a new methodological approach has been developed which implies staged realization. Stage one was aimed at the search for integral clinical-dynamic characteristics as well as social and psychological properties to make identification of the clinical phenotype reliable. Stage II--at introduction of integral constitution-morphology indicators representative of the disease predisposition-stability. The analysis of medicosocial characteristics for the last 8 years has been performed at Stage III. Calcium homeostasis and related hormones and enzymes were evaluated at Stage IV. The data obtained permitted identification of a complex of structural manifestations underlying alcohol embryopathy of the brain.

Alcoholism↗
PubMed1991

[The effect of endogenous factors and physical loading on the formation of moisture excretion and detoxication by the lungs].

Overall 101 students (a control group), 68 persons from an ambulatory group with exogenous factors at risk for pulmonary diseases, and 122 patients with exacerbation of nonspecific pulmonary diseases were examined for the volume of exhaled air condensate, the content in it of medium-weight molecules and protein by means of two methods (according to Lowry and by adsorption using polysorb). The students were found to have the worst parameters. Exacerbation of the disease led to their increase. Exercise blocked transport of water, protein and medium-weight molecules to the condensate, whose intensity depended on the age, sex and body mass. This stresses the importance of exogenous factors in the maintenance of moisture excretion and detoxication by the lungs. It is recommended that the new methodological approach to assessing the response to exercise according to moisture excretion function of the lungs may be applied.

Adult↗
PubMedDate not supplied

[MEDILAB and the problems of psychophysiological support of manned space flights].

This paper discusses current problems of psychophysiological support of manned space missions and presents the concept of a psychophysiological complex of the orbital biomedical laboratory Medilab and other advanced space vehicles based on new methodological approaches. The paper describes principles of selection of psychophysiological methods to be used in Medilab programs as well as their instrumental, mathematical, hardware and software structures.

Aerospace Medicine↗
PubMed1989

[Effect of calcium ions on the interaction of troponin C with rabbit skeletal muscle troponin I and troponin T immobilized on polyvinyl chloride].

Using a new methodological approach based on the binding of 125I-labeled troponin C to troponins I and T immobilized on polyvinylchloride, the Ca2+-dependent interaction of troponin components was investigated. In the absence of Ca2+, two types of sites of troponin C--troponin T interaction were revealed (Kd = 3.6.10(-8) M and 5.10(-7) M). It was found that Ca2+ induced the formation of a troponin I--troponin C complex which was resistant to 5 M urea (Kd = 4.10(-8) M). In the absence of Ca2+, the binary troponin T--troponin C complex also revealed two types of interaction sites (Kd = 7.1.10(-8) M and 2.10(-7) M); however, in the presence of Ca2+ only high affinity sites whose number increased almost 2-fold were revealed. The events that may take place in the whole troponin complex during Ca2+ binding by troponin C are discussed.

Animals↗
PubMed1989

[Methodologic aspects of the propaganda on a sober life style].

The ways for raising effectiveness of propaganda of a sober mode of life were analyzed. New methodological approaches were set forth and the necessity of establishing close links between propaganda and specific preventive measures were demonstrated. Highlighted were alcohol-related sociopsychological stereotypes which should be consistently combated. Dialogues were recommended as the most rational means of interaction with the audience.

Alcoholism↗
PubMedDate not supplied

Critical remarks on the stereotaxic treatment of epilepsy.

The analysis of experiences with 43 patients treated stereotaxically for epilepsy, shows that the stereotaxic method can play an important role 1) in the investigation of the structures in epileptic activity; 2) in proper management of these cases. According to deep electrode records, the epileptic focus seems to be like a system of anatomical structures, which are functionally interdependent, and its relationship can be plotted on a schematic graph, which must be calculated in the strategy of treatment with the combined performances. In spite of this results are not satisfactory. New methodological approaches should be devised, such as longitudinal stereotaxic hippocampectomia, which is suggested as promising.

Brain Stem↗
PubMed1984

[Electroroentgen scanning in the diagnosis of bone metastases].

For diagnosis of metastatic bone pathology x-ray and radionuclide studies were combined into one: electroroentgenoscanography. A total of 48 patients with different sites of a primary tumor process were examined using 99mTc-pyrophosphate. Electroroentgenograms were obtained with the help of the Soviet ERGA-MP apparatus in the negative regimen without enlarging the scale of skeletal imaging. The scanning was done on the Scinticart and Deltronix-Nuclear units. The peculiarity o this technique is visualization of the skeleton 2-4 and 20-24 h after i.v. injection of the radioactive indicator. Bone pathology was observed in 85.4% of the cases, and the results of the roentgenoradionuclide studies were identical. In 18 out of the 41 patients visualization of the skeleton with 99mTc-pyrophosphate made it possible to specify the number of foci of pathological bone tissue transformation. In 5 patients (10.4%), secondary metastatic involvement of the skeleton was found by the radionuclide method only. The results of repeated x-ray studies of these patients over the period of 3 months were negative. Clinical-radionuclide information was the reason for revising the clinical staging of tumors and correcting therapeutic methods. The new methodological approach in the diagnosis of bone pathology: electroroentgenoscanning on the 1st and 2nd days after injection of 99mTc-pyrophosphate opens up other opportunities for diagnosing metastatic involvement of the osseous system.

Bone Neoplasms↗
PubMed1984

[Heterogeniety of the amino acid pool for protein synthesis in Ehrlich ascites carcinoma cells].

Using a new methodological approach based on a step-wise labelling with [14C] and [3H] amino acids, it was demonstrated that the Ehrlich ascite carcinoma cells are capable of utilizing both intracellular and extracellular amino acid pools for protein synthesis. The inhibition of amino acid transport into the cells is accompanied by a more intensive utilization of the exogenous pool. The described procedure permits to calculate the specific radioactivity of the tRNA-bound amino acid and the absolute rate of protein synthesis.

Amino Acids↗
PubMed1993

[The role of membrane lipids in regulating the function of neuromediator receptors].

The role of membrane lipids in the interactions between neurotransmitters and membrane-bound receptors has been studied with regard to: (i) the specificity of interactions between the lipids and the neurotransmitter molecules; (ii) the modulation of the receptor binding activity by annular lipids and (iii) the physical state of the membrane lipid bilayer as a whole. These aspects are discussed for various receptor systems. Particular emphasis has been placed on the lipid regulation of the ligand binding to opioid receptors. A new methodological approach to the study of receptor regulation by lipids is considered. This approach consists in the study of spontaneous inactivation of selective ligands binding as applied to the study of lipid regulation of opioid receptors in rat brain.

Animals↗
PubMed1993

[Nervous system diseases in men and women].

The authors have collected data from special literature on neurological diseases and grouped them by sex prevalence. Such factors as hereditary, metabolic-endocrine, immunological, emotional, social have great implications in sex distribution of neurological disorders. It is stated that this problem needs further investigation, new methodological approaches which could appear promising in studying pathogenesis of numerous diseases and help in designing effective treatments.

Adult↗
PubMedDate not supplied

[The assessment of mental disturbances (mental illness) as a qualifying sign of the severity of bodily injuries].

Analyzes the problem of assessing the severity of bodily injury leading to mental disorders in the victim. Discusses a working classification of mental disorders resultant from various environmental factors (injuries), intended for forensic medical experts, psychiatrists, and physicians of other specialties. Offers a new methodological approach to forensic medical and psychiatric expert evaluation of such cases. Describes the typical examples from practical forensic medical and psychiatric expert evaluations.

Accidents, Traffic↗
PubMed1997

[Theories of nursing professionals about the elderly].

Our study emphasizes the implicit theories of nursing professionals about the elderly and their influence on nursing behavior styles. According to our central hypothesis we expected a correlation between the differentiation of attitudes towards the elderly and the quality of nursing interventions. By means of a new methodological approach based on Forgas' theory of "social episodes" we investigated attitudes towards the elderly and behavior intentions in specific nursing situations. The sample consists of 133 professionals working in nursing homes for the elderly or in home care services. In a first step the structure of attitudes towards the elderly was examined by employing multivariate techniques, e.g. factor analysis and multidimensional scaling. Three aspects of older patients' competence constitute the images which influence nursing personnel's interactions with the elderly. In the next step a significant correlation between the complexity of attitudes towards the elderly and the quality of nursing behavior could be demonstrated. In general, the findings in our sample support personalized rather than stereotyped perceptions of the elderly. In particular such qualities will be stressed by nursing professionals which facilitate or disturb the nursing process.

Aged↗
PubMed1976

Pneumatonographic studies on normal and glaucomatus eyes.

A new methodological approach, embodied in the pneumatonograph, has been used to study the intraocular pressure, intraocular pulse and aqueous humor dynamics of normal and glaucomatous eyes. Comparative measurements of intraocular pressure in seated subjects by the Goldmann instrument and the pneumatonograph indicate close agreement over a wide range of pressures. On changing from the sitting to the supine position, it has been found by pneumatonometry that there is a significant increase of intraocular pressure in all eyes. In glaucomatous eyes, this postural response ranged up to as high as 12 mm Hg. Comparison of Schiotz and pneumatonometric pressure measurements on supine patients showed that the Schoitz values are significantly lower. This discrepancy of the values is in keeping with recent studies indicative that the Schiotz calibration is in error by 3-6 mm Hg. The coefficient of outflow facility was measured by a procedure of applanation tonography employing pressure-volume relations for the living human eye. The range of values found for normal eyes was significantly different from those of glaucoma eyes. It is concluded that pneumatonography is a useful method for improving the effectiveness of glaucoma diagnosis and clinical management.

Adult↗
PubMed1998

[In vitro study of the modulating effect of antitubercular agents on the rosette formation response in patients with pulmonary tuberculosis].

The wide medical application of new highly active antituberculous agents (ATA) having a definite mechanism of action on immunological homeostasis makes pharmacological regulation of immunological responses real in patients with pulmonary tuberculosis. The purpose of this study was to examine the effect of major ATA on the body's immunological responsiveness in vitro, i.e. by the changes in E-RFC used as a loading test, their immunoactive properties were examined with and without addition of ATA. The study provided a new methodological approach which may help in more effectively determining the nature of effects of the study ATA on the qualitative and quantitative parameters of the T system, in clarifying whether ATA have certain immunoregulating properties, and in quantitatively defining the magnitude of their expression. The used parameter E-RFC is an adequate test for studying the immunoactive properties of ATA acting primarily on cell immunity. Thus, this offers scope in practical medicine for goal-oriented regulation of an immune response in different tuberculosis infections by using appropriate ATA.

Antibiotics, Antitubercular↗