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Biomedical subjects

R T Toguzov

Publications and source records attributed to R T Toguzov.

At least 19 recordsLinked to original sources
PubMed2006

[Use of a scanner to register the results of enzyme immunoassay in the standard microplates].

Whether a commercially available scanner might be used as a vertical photometer of 96-well microplates for enzyme immunoassay (EIA) was studied. The analytical characteristics of the scanner in this regard were assessed, by comparing the findings with the respective photometric data obtained by a "VICTOR" EIA analyzer. It is concluded that the scanner registration system in combination with "Expert-Lab EIA" may be used in all types of EIA. The scanner system provides additional possibilities as compared with the conventional photometric analyzers.

Biomarkers↗
PubMed2004

Disorders in restructuring of T-cell receptor gamma-chain in malignant skin lymphomas.

Disorders in restructuring of T-cell receptor gamma-chain in DNA from skin biopsy specimens and peripheral blood lymphocyte of patients with malignant skin lymphomas at different stages of the disease were detected by PCR. Nucleotide sequences of monoclonal T-cell receptors were determined. The study showed that DNA sequences from the skin and lymphocytes did not coincide in some cases.

Adult↗
PubMed2000

[Chromatin nuclear proteins in evaluation of the effectiveness of treatment of patients with psoriasis].

Histone proteins and nucleic acid precursors were studied in 10 normal subjects and 20 patients with disseminated psoriasis before and after combined therapy including Enkad. A drop in the concentrations of H1 histones was detected in the blood lymphocytes and plasma in parallel with an increase in the concentrations of arginine-rich histones and a many-fold decrease in the acid-soluble fraction representing a pool of nucleic acid precursors. After combined therapy the ratio of lysin- and arginine-rich nuclear proteins in blood lymphocytes changed significantly and approximated the normal value; the distribution of histone-like proteins virtually did not change in the plasma, but the level of plasma and erythrocyte acid-soluble fraction normalized. This indicates positive changes in nucleic acid transport after therapy. The authors demonstrate the possibility of these findings for evaluation of the treatment efficiency.

Adolescent↗
PubMed1998

[Metabolism of purine compounds in psoriasis].

The pool of free purine derivatives and activities of the key enzymes of purine metabolism (adenosine deaminase, purine nucleoside phosphorylase, and 5'-nucleotidase) in lymphocytes, erythrocytes, and epidermis homogenates were measured in 20 normal subjects and 15 patients with psoriasis by high-performance liquid chromatography. The levels of AMP, GMP, and IMP purine monophosphates are decreased in the epidermis and red cells of psoriasis patients, whereas the final products of hypoxanthine, xanthine, and uric acid metabolism are accumulating, and the activities of ADA and PNP are increased double in the skin, all this indicating purine derivatives catabolism.

Adenosine Deaminase↗
PubMed1991

Changes of nucleotide patterns in liver, muscle and blood during the growth of Ehrlich ascites cells: application of the reversed-phase and ion-pair reversed-phase high-performance liquid chromatography with radial compression column.

The pool of purine compounds was analysed in liver, skeletal muscle and blood of mice during the growth of Ehrlich ascites tumour cells. Three fast isocratic high-performance liquid chromatographic methods were used. (1) Determination of nucleotides by an isocratic ion-pair reversed-phase chromatography with a 10 mM ammonium phosphate buffer containing acetonitrile and tetrabutylammonium phosphate. (2) Separation of nucleosides and nucleobases in cell extracts by a reversed-phase system with methanol and 50 mM potassium phosphate buffer as eluent. (3) Nucleosides and nucleobases in body fluids were analysed by a reversed-phase system with 10 mM potassium phosphate containing methanol. These methods allow the rapid determination of purine compounds in small biological samples from various cell types and body fluids, with high accuracy and sensitivity. The pool of cellular nucleotides increased during the exponential phase of tumour growth. Adenosine accumulated significantly in all tissues in the stationary phase of tumour growth.

Animals↗
PubMed1990

Ion-pair high-performance liquid chromatography of purine compounds in the small intestinal mucosa of children with coeliac disease.

Isocratic methods are described for the separation of purine compounds in specimens of jejunal mucosa available by peroral biopsy from patients with coeliac disease. The first mode provided separation of both the ionic nucleoside monophosphates and the non-ionic nitrogen bases and nucleosides. The second mode was applicable to analyses of the nucleoside mono-, di- and triphosphates only. These chromatographic procedures were carried out with tetrabutylammonium phosphate as an ion-pair modifier and different concentrations of acetonitrile in the mobile phase. The modes are flexible in that they permit the optimization of the separation of these compounds according to the purpose of the investigation. The results of studies on purine metabolite patterns in coeliac mucosa are discussed.

Adolescent↗
PubMed1990

The catabolism of endogenous adenine nucleotides in rat liver mitochondria.

The degradation of intramitochondrial adenine nucleotides to nucleosides and bases was investigated by incubating isolated rat liver mitochondria at 37 degrees C under non-phosphorylating conditions in the presence of oligomycin and carboxyatractyloside. Within 30 min the adenine nucleotides were degraded by about 25 per cent. The main products formed were adenosine and inosine the contents of which increased five- to sevenfold. Compartmentation studies revealed that about 50 to 60 per cent of the adenosine formed remained inside the organelles whereas inosine was almost completely released into the surrounding medium. Outside the mitochondria only very small amounts of adenine nucleotides were detected. Similar incubations in the presence of [14C]-adenosine yielded no [14C]-inosine ruling out extramitochondrial adenosine deamination. It is concluded that endogenous adenine nucleotides can be degraded in mitochondria via AMP dephosphorylation and subsequent adenosine deamination. A purine nucleoside transport system mediating at least the efflux of inosine from the mitochondria is suggested.

Adenine Nucleotides↗
PubMed1990

[Metabolic pool of purine compounds in erythrocytes of mice during growth of transplanted tumors].

The pattern of purine derivatives was studied in the erythrocytes of C3HA and ICR mice during Hepatoma 22 and Ehrlich ascites tumor cells growth. Host erythrocytes purine nucleotides, nucleosides and bases were affected by the implanted tumors. The results indicated that the host erythrocytes markedly concentrated adenine and guanine nucleotides on the 5th and 11th-12th day of tumor growth. By contrast, content of nucleosides and bases were sharply decreased during the log growth phase (5th day) with the restoring of these precursors within the 11th-12th day (plateau phase). These observations indicate that aspects of the purine compounds metabolism in host erythrocytes are linked with tumor development.

Adenine Nucleotides↗
PubMed1990

[Effect of chronic intrauterine hypoxia on purine compound metabolism in the erythrocytes of newborn infants in the early neonatal period].

The content of purine compounds in red blood cells was measured and compared in 21 neonates with a history of chronic intrauterine hypoxia, depending on the condition at birth and the early period of adaptation. The content of purine compounds in whole blood was measured at the moment of birth and on days 1, 3 and 5 of life. It has been disclosed that the pattern of purine metabolism abnormality in funic red blood cells makes it possible to predict the course of the early period of adaptation. Changes in the content of hypoxanthine and inosine monophosphate appeared to be most remarkable.

Chronic Disease↗
PubMed1990

Metabolism of purine and pyrimidine compounds in erythrocytes of tumor-bearing mice.

The pattern of purine and pyrimidine derivatives was studied in the erythrocytes of C3HA and ICR mice during Hepatoma 22 and Ehrlich ascites tumor cell growth. Concentrations of purine nucleotides, nucleosides and nucleobases of host erythrocytes were changed after the implantation of the tumors. The host erythrocytes markedly concentrated adenine and guanine nucleotides both during logarithmic and plateau phase of tumor growth (5th and 11-12th days after inoculation of the tumor). The contents of nucleosides and nucleobases in the red blood cells were decreased during the logarithmic growth phase but restored within the plateau phase.

Animals↗
PubMed1989

Mitochondrial metabolism of guanine nucleotides. Possible role of guanosine.

The catabolism of intramitochondrial guanine nucleotides was examined. During 30 min incubation of rat liver mitochondria at 37 degrees C in the presence of oligomycin and carboxyatractyloside, guanine and xanthine were formed and appeared in the medium. Under these conditions, the direct conversion of GMP to guanine by hypoxanthine-guanine phosphoribosyltransferase is suggested to be the main catabolic route within the organelles. Only very small amounts of guanosine were produced and detected both inside and outside the organelles. [14C]Guanosine and [14C]inosine were taken up by the mitochondria. Therefore, guanosine is suggested to be a precursor of intramitochondrial guanine nucleotides.

Animals↗
PubMed1989

[Nucleic acids of the gastric mucosa in chronic gastritis and cancer].

The levels of DNA and RNA in gastric mucosa were assayed in 50 patients suffering various morphological variants of chronic gastritis and 73 cases of stomach cancer. Nearly identical rise in nucleic acid concentrations was identified in both atrophic gastritis and stomach cancer as compared to atrophy-free gastritis and normal condition. A link between atrophic gastritis and gastric cancer was suggested.

Biopsy↗
PubMed1989

[The pool of free purine and pyrimidine nucleosides and bases in the thymocytes, and splenic T- and B-lymphocytes of C3HA mice during the growth of solid hepatoma 22a].

Using reverse phase ion pair high performance liquid chromatography, the levels of free adenosine, inosine, adenine, xanthine, hypoxanthine, guanine and deoxycytidine in thymocytes and splenic T- and B-lymphocytes of C3HA mice, were studied under normal conditions and at different times (5 hrs, 1, 2, 3, 4, 5, 8 and 20 days) after transplantation of solid hepatoma 22a. The adenosine and inosine levels in thymus and spleen lymphocytes were 5 to 10 times as low as that of purine bases. Inosine was totally absent in T-and B-lymphocytes. The absolute content of adenine and guanine in thymus and spleen lymphocytes was higher compared to purine bases. It was shown that in all cases studied the decrease in hypoxanthine, xanthine and guanine levels in T- and B-lymphocytes during maximal tumour growth, i.e., on the 5th and 8th post-inoculation days as well as at the terminal period (20th day), was correlated with the decrease in the adenosine deaminase and functional activities of these cells. The level of free adenine in thymocytes and spleen T-lymphocytes during tumour growth showed a 2-4-fold increase in comparison with normal values. A dramatic decrease of intracellular concentration of deoxycytidine was observed in thymocytes and spleen T- and B-lymphocytes beginning with the 5th hour and over the whole subsequent period. The key role of the deoxycytidine decline during tumour growth as a possible cause of simultaneous impairment of DNA synthesis and purine deoxyribonucleoside phosphorylation in lymphocytes is discussed.

Adenine↗
PubMed1989

[Metabolic pool of purine and pyrimidine compounds in the venous blood of patients with myocardial infarction and stenocardia].

Venous blood acid-soluble fraction was investigated by means of high-efficiency liquid chromatography in patients with myocardial infarction and angina pectoris. Myocardial ischemia is shown to result in marked changes of purine and pyrimidine metabolism. A rise in intermediate and end products of purine metabolism (inosine, hypoxanthine, xanthine, uric acid), and the emergence of thymin and thymidine were demonstrated in venous blood of patients with myocardial infarction and angina pectoris.

Adult↗