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N G Stepanova

Publications and source records attributed to N G Stepanova.

36 records · Page 2Linked to original sources
PubMedDate not supplied

[Effect of deproteinization on the in situ chromatin staining with 7-aminoactinomycin D].

The possibility of use of 7-amino-actinomycin D (7aAMD)--fluorescent analog of actinomycin D--as a specific dye for DNA staining in the suspended cells was studied by means of laser flow-cytometry. The optimal conditions for staining were obtained: 7aAMD concentration 10(-5) M, pH 7, staining time 20 min, 37 degrees C, ionic strength 0.15 M Na+. In this case the fluorescent signal is proportional to the DNA amount and coefficient of variation is about 0.03. The influence of the stepwise extraction of the proteins from chromatin also was studied. In the course of the salt deproteinization the fluorescence intensity gradually rose thus showing the increase of the binding sides-number. The deproteinization of cells nuclei by 0.1 HCl increased the number of binding sites 2.5 times more. It was shown that the incubation of cells with RNAse at elevated ionic strength (0.3-0.7 M NaCl) leads to an additional increase of the cell fluorescence and produces no effect at low and normal ionic strength. The deproteinizing effect of RNAse and its possible mechanism is discussed.

Animals↗
PubMedDate not supplied

[Determination of aldolase A activity in the serum of patients with myocardial infarction].

A procedure is described for estimation of aldolase of the type A-a tissue-specific enzyme of myocardium--in blood serum under conditions of myocardial infarction. The rate of the enzymatic reaction was estimated by monitoring production of heptulose-1,7-diphosphate. Erythrose-4-phosphate and dihydroxyacetone phosphate were used as substrates of the reaction. High rates of the reaction product accumulation was observed if the compounds, shifting the reaction K'equi, were not added into the experimental samples. Sensitivity of the test was 3-fold increased due to modifications of the original method. Clinical experience with the test showed that activity of aldolase of the type A was distinctly higher in blood serum of patients with myocardium infarction as compared with the healthy donors or with the patients with ischemic heart disease.

Clinical Enzyme Tests↗
PubMedDate not supplied

[Repetitious DNA in the genome of Drosophila lummei Hackman and its role in replication and chromosome behavior in mitosis].

The toromere previously found by other workers in the distal end of the sixth chromosome (microchromosome) of D. lummei was studied using differential staining of D. lummei giant chromosomes. The toromere which was first described as a quinacrine-bright structure appears as a C-positive body. Quantitative cytofluorometric analysis showed a significant increase in toromeric DNA under low temperature conditions. In situ hybridization of 125I nick-translated D. virilis sDNA (all three satellites were included in the sample) with polytene chromosomes of D. lummei larvae cultured at 12 degrees C revealed no label incorporation into the toromere region. However in situ hybridization of [3H]RNA complementary to highly repetitious DNA of D. lummei and D. virilis (C0t = 10(-1)--10(-2)) with polytene chromosomes of the larvae cultured at 12 degrees coupled with banding studies enable us to conclude that the toromere probably contains AT-rich repeated DNA. Well-developed toromere in the sixth chromosome of D. lummei was also demonstrated at normal temperature (25 degrees) in interspecific hybrids. The role of the toromere structure in the mitotic behaviour of microchromosomes and their replication pattern is discussed.

Animals↗
PubMedDate not supplied

[The use of halotherapy for the rehabilitation of patients with acute bronchitis and a protracted and recurrent course].

Halotherapy was used for rehabilitation in 25 patients with acute bronchitis of long-standing and recurrent types. The main therapeutic action was ensured by aerodispersed medium saturated with dry highly dispersed sodium chloride aerosol, the required mass concentration being maintained in the range of 1 to 5 mg/m3. Therapy efficacy was controlled through assessment of clinical, functional, immunological and microbiological findings. Metabolic activity values were taken into consideration as well. Positive dynamics of the function indices in the clinical picture resulted from elimination of pathogenic agents, control of slowly running inflammatory lesions and stimulation of some immune system factors. Favourable changes in metabolic activity were present: normalization of serotonin excretion, marked decrease of unbalance in lipid peroxidation-antioxidant system.

Acute Disease↗
PubMedDate not supplied

[Determination of inorganic phosphate in the presence of phosphocarbohydrates].

The molybdate methods were shown to have limited application for estimation of inorganic phosphate (P1) in the samples containing phosphocarbohydrates. The definite concentrations of phosphosugars caused the formation of blue molybdenic color. The ascertained critical concentration of Pi and the maximal content of phosphocarbohydrates in the solution studied enabled to estimate P1 in the presence of phosphorus esters of carbohydrates with use of the specific, sensitive and simple method.

Methods↗