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Biomedical subjects

A I Shchegolev

Publications and source records attributed to A I Shchegolev.

54 records · Page 3Linked to original sources
PubMed1983

[Quantitative histophotometric study of liver dehydrogenase activity during temporary ischemia of the extremities].

This prospective study depicts quantitative histophotometric characteristics of the changes in the histoenzymologic spectrum of the liver in the course of temporary ischemia of the extremities with subsequent revascularization. The increase in the activities of dehydrogenases under study in the course of a 3-hour ischemia, and the decrease of these parameters in 6- and 12-hour ischemia was discovered, that was determined as a compensatory response followed by the period of compensation exhaustion and the development of the period of complete exhaustion. The data of the study of drug correction of the postischemia syndrome confirmed the rationality of the efforts that were made. A special program developed for computer processing of histological data allows rapid adaptation of the methods for different histophotometric examinations with the use of TV analyzer of the picture, this creating wider possibilities as compared to the known analogs.

Animals↗
PubMedDate not supplied

[The prolonged use of calcium antagonists in myocardial infarct in rats: their effect on hemodynamics and the contractile function and morphology of the heart muscle].

Experiments on rats with myocardial infarction induced by occlusion of the left coronary artery were made to explore the influence of calcium antagonists injected intraperitoneally for a long time (daily, for 21 days) on hemodynamics, contractile function and morphology of the heart muscle. It has been shown that verapamil (0.5 mg/kg), diltiazem (2 mg/kg) and nimodipine (20 micrograms/kg) do not exert under those conditions any noticeable effect on pump and contractile heart functions. Administration of verapamil in a doze of 2 mg/kg enhanced heart failure. The drugs under study normalized the response of contractile heart function to volumetric load, which is related to a considerable measure to the acceleration of reparative processes in the myocardium.

Animals↗
PubMedDate not supplied

[Histological variants of parasympathetic paragangliomas (chemodectomas) of the neck and morphological variants of their malignancy].

Histotopograms of 28 chemodectomas have been studied. Principal microscopic features of malignancy are as follows: structural atypia (complete in solid or fibrous variants) or partial (alveolar chemodectoma) loss of alveolarity as the most important sign of organotypia; another sign of malignancy is cell cataplasia (cell and nuclear polymorphism, change in nuclear-cytoplasmic relationship in the direction of its increase, nuclear hyperchromatism, appearance of large ungly hyperploid nuclei, mitotic activity of tumour cells in one case. Incomplete angiogenesis characteristic for malignant tumours was also detected. Invasive growth in the majority of chemodectomas in the form of partial growth through the walls of great vessels and ubiquitous growth through the walls of small vessels were present in most chemodectomas. Thus, there is a basis to claim that the chemodectomas studied are malignant tumours although they are characterized by a slow (years) growth and slow progression.

Cell Nucleus↗
PubMedDate not supplied

[Focal nodular hepatic hyperplasia].

Macroscopic and histological characteristics of focal nodular hyperplasia (FNH) of the liver are presented. Characteristic microscopic signs are the presence of numerous septs with many biliary ducts. Hepatocytes with diploid number of chromosomes show negative Ki-67 and p53. Ultrastructure of hepatocytes in FNH does not differ from that of normal cells of the liver.

Adult↗
PubMedDate not supplied

[Biliary cystadenoma].

A case of hepatobiliary liver cystadenoma in a 45-year-old female is reported. The tumour looked like a multifocal cyst 18x12x8 cm in size with yellowish content. Inner surface was represented by a column epithelium with nuclei located in the basal part of the cells. Immunohistochemically expression of cytokeratin 19 (similar to the epithelium of bile ducts) was revealed.

Bile Duct Neoplasms↗
PubMedDate not supplied

[Proliferation of fat cells in lipomas].

Common lipomas and destructive ones (intramuscular, infiltrating, necrotizing and destroying surrounding tissues) were studied in 9 patients electron-microscopically and radioautographically. The adequacy of necrotizing processes and regeneration was observed: normal fat tissue-lipoma-destructive lipoma. In the latter besides pronounced destruction of tissue (adipocytes, vessels, muscles at the border with tumour), there was accelerated differentiation of preadipocytes from the cells-precursors (fibroblasts and undifferentiated cells of the vascular wall), hypertrophy of preadipocytes (their size and number of nuclei increase) and their proliferation. The process of malignant transformation in a destructive lipoma may be so much pronounced that DNA synthesis may be observed in the mature lipocyte (this has not been described so far).

Adipocytes↗
PubMedDate not supplied

[Adult hepatoblastoma].

A rare case of hepatoblastoma is reported in a female of 47 years of age with literature review of these tumors in the adults. Microscopically the tumor was represented by the cells of embryonal and fetal types. Immunohistochemically expression of low-molecular cytokeratins as well as that of S-100 protein and hepatocyte antigen was observed.

Biomarkers, Tumor↗
PubMedDate not supplied

[Classification of pancreatic exocrine tumours].

Current international histologic classification of exocrine pancreatic tumours is presented. Macro- and microscopic characteristics of benign and malignant tumors are described. The role of immunohistochemistry in differential diagnosis is shown.

Diagnosis, Differential↗
PubMedDate not supplied

[The role of the vascular factor in the reorganization of water metabolism in denervated liver after bacterial endotoxin poisoning].

Intoxication with bacterial lipopolysaccharide (endotoxin) is accompanied by considerable rearrangements in the systems of blood microcirculation and water metabolism of the liver. These rearrangements are manifested as increased sinusoid area, changed total area of the cytoplasm and nuclei as well as the nucleocytoplasmic ratio in hepatocytes, increased content of total water in the organ, and changed magnetic relaxation properties (spin-lattice and spin-spin relaxation times). Preliminary parasympathetic denervation of the liver (vagotomy) changes the pattern of the organ response to bacterial endotoxin poisoning as indicated by the kinetics of studied morphological and biophysical parameters.

Animals↗
PubMedDate not supplied

[Primary squamous-cell carcinoma of the liver].

The authors describe one case of squamouscell carcinoma of the liver, which developed in a 54-year-old male. The gross tumor was a cyst, 10 cm in diameter, with the brown contents. A histological study revealed high-grade differentiated squamous-cell carcinoma without keratinization. An immunohistochemical study showed a positive reaction with cytokeratin 19 and PCNA expression in single nuclei of tumor cells.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

[Use of automatic cytophotometric analysis for assessing the hepatotropic action of ethanol].

It has been shown in experimental chronic intoxication that there is a close correlation between the dose of ethanol, microscopic appearance of the liver, the content of DNA, RNA, protein, glycogen in hepatocytes and structural parameters of nuclear chromatin of these cells. It is concluded that automatic cytophotometric analysis of the structure of hepatocyte nuclei holds promise for an accurate quantitative evaluation of the hepatotropic action of chemical substances and drugs.

Alcoholism↗
PubMedDate not supplied

[The effect of endogenous opioid peptides and their synthetic analogs on T-cell immunity].

The effects of the endogenous opioid peptides met- and leu-enkephalins and their synthetic analogs such as DAGO, DADLE, dalargin on the formation and activity of cytolytic T lymphocytes in response to alloantigen stimulation were studied in the unidirectional mixed culture of lymphocytes. It was shown that the maximum stimulating effect of the opioids manifested itself on their addition 24-48 hours after the initiation of incubation and on addition of suboptimal concentrations of an antigen to the culture. The selective opioid receptor ligands mu- and delta-types + (DAGO and DADLE) have a heterodirectional effect on the formation of specific T killer cells in the mixed culture of lymphocytes.

Animals↗