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Biomedical subjects

V N Bliumkin

Publications and source records attributed to V N Bliumkin.

At least 19 recordsLinked to original sources

[Aggregates of islet cells, their structure and insulin-producing activity during cultivation in vitro].

Purified rat islets were dissociated into single-cell suspension with an EDTA-Trypsin treatment. During a stationary culture in vitro the islet cells reassociated forming aggregates (neoislets). Electron microscopy revealed that the aggregates consisted mostly of beta-cells and not numerous alpha-cells. They showed a good insulin-secreting capacity and were able to increase insulin release in response to glucose plus theophylline. The lack of passenger leukocytes makes the neoislets particularly suited for experimental and clinical transplantation.

Animals↗

[Some characteristics of the histological structure of the fetal bovine pancreas].

Some properties of histological structure of fetal bovine pancreas were demonstrated using light microscopic methods. The different forms of acino-insular complexes were described: 1) acino-insular complexes with single B-cells including epithelial layer of acini; 2) acino-insular complexes with segmental (sector) localization of insular cell groups; 3) acino-insular complexes with small and more large groups of endocrine cells timely contacted with acini; 4) acino-insular complexes at the stage of separation of endocrine cell groups (microislets) from acini. The consideration of acino-insular complexes in morphogenesis of bovine endocrine pancreas in discussed.

Animals↗

[Preparation of liver cultures from human embryos].

The cultures were obtained from 9-12-week-old human embryonic liver. 24-36 hours after seeding the cultures containing a multilayer focus of adhesion and a monolayer growth zone were formed. The growth zone contained hepatocytes with bile pigment granules in the cytoplasm. The formation of culture monolayer coincided with the elimination of hemopoietic cells.

Cell Separation↗

[Transplantation angiopathies and vasculitis after allogeneic grafting of cadaver kidney to humans].

The material of 560 allogenic corpse kidney transplantations was studied and the conclusion drawn on the possibility of the development in the kidney graft of two types of vascular lesions. The first type is referred to as a genuine angiopathy the causes and structure of which change depending on the time of donor kidney persistence in the recipient. The second type is regarded as immune vasculitis. The role of some immune and non-immune factors in the development of transplant vascular bed changes is discussed.

Adult↗

[Immunologic typing of splenic lymphocytes from human fetuses--donors of pancreatic islet cell cultures].

To determine the HLA-phenotype of a potential donor of pancreatic islet cells, use was made of lymphocytes from 18-25-week-old human fetuses. The HLA-phenotype was clearly established in 39 out of 52 cases. In 13 cases, the authors failed to reveal histocompatibility antigens because of low viability of lymphocytes. The relationship was ascertained between the detectability of HLA-antigens in fetal donors and cytophysiological characteristics of islet cell cultures prepared from the pancreas.

Fetus↗

[Floating cell cultures of the fetal pancreas].

A simple method for preparing human and animal fetal pancreatic cell cultures has been developed. It is based on enzymatic treatment of the fetal pancreatic tissue with collalitine in combination with microdissection. As a result of subsequent cultivation there form floating cytotypic and organotypic cultures consisting mainly of B cells in different phases of the secretory cycle. The floating cultures prepared by the above-described method produce insulin and can be successfully used in experimental and clinical transplantology.

Culture Techniques↗

[Intrasplenic xenotransplantation of human fetal pancreatic islet cell cultures in rats with experimental diabetes mellitus].

Islet cell cultures obtained from the pancreas of human embryos were transplanted to the spleen pulp of rats with alloxan diabetes mellitus. During 1-2 weeks after transplantation, 6 of the 8 recipients manifested a decrease in glycemia to normal or almost normal. The antidiabetic effect of xenotransplantation of islet cell cultures was well preserved throughout the entire observation period (up to 4 months). Two recipient rats with stable normoglycemia were subjected to splenectomy. One week after operation the animals manifested the recurrent grave diabetic status. Histological study of the removed spleen has shown the red pulp to contain the accumulations of implanted islet cells.

Animals↗

[Morphologic criteria for kidney preservation].

Comparative histoenzymatic, electron microscopic and histologic studies of kidney preservation without perfusion have shown that the pattern of precipitation of tetrazolium reaction products correlates with the degree of ultrastructural damage to the epithelium of renal tubules. A previously made suggestion on the possibility of using the tetrazolium reactions for estimating the degree of preservation of ischemized organs and tissues has been confirmed.

Animals↗

[Reconstruction of the tubular epithelium of allotransplanted kidneys of man in late periods following transplantation].

The structure of allotransplanted kidneys (AK) from human cadavers that remained in the recipient's body for a long time (4 months-6 years) has been studied. AK that preserved good function up to the patient's death not consequent on the transplant insufficiency showed a weak immunocellular connective tissue, with the epithelium of proximal canaliculi being cytologically reconstructed. The reconstruction lay in formation of numerous polykaryocytes having a hypertrophied brush-like outline. This phenomenon ("proximal polykaryocytosis") is assessed as a manifestation of regeneratory potencies of the epithelium of AK proximal tubules in late periods after transplantation. Chronic moderate hypoxia of AK was conducive to reconstruction of the epithelium of the nephron proximal part. Inadequate function of AK was related to the development of chronic rejection resistant to the treatment, and AK demonstrated an intensive immunocellular reaction and developed gross sclerosis that produced atrophy of most AK tubular.

Epithelium↗

[Microcinematographic study of pancreatic islet cells from fetal cattle].

The growth characteristics of pancreatic islet cell cultures of bovine fetuses were investigated by the method of time-lapse cinemicrography. These monolayer cultures consisted of epithelial cells only. Under the influenc of high glucose concentration in the growth medium (up to 300 mg per 100 ml) there occurred an activation of mitochondrial apparatus of the islet cells, stimulation of cytogranulokinesis, and intensification of accumulation of the secretory granules with the subsequent degranulation of the islet cells. These data were compared with the results of cytological control of fixed and stained culture.

Animals↗

[Morphology of the juxtaglomerular apparatus of allotransplanted human cadaver kidneys in the late periods following transplantation].

Histological structure of 13 allografted human cadaver kidneys was observed at late stages after transplantation (from 121 days to 3 years and 10 months). In the grafted kidneys with a well-preserved structure the microscopic picture of the juxtaglomerular apparatus (JGA) failed to differ significantly from the JGA in the control. This conclusion was confirmed by the karyometric data and by the results of the juxtaglomerular index calculation. In the allografted kidneys with severe destructive and dystrophic alterations there can occur a partial or complete JGA involution.

Cadaver↗

[Insulin-forming activity of monolayer cultures of pancreatic islet cells from cattle fetuses].

The radioimmunological method was applied to the study of insulin content in the growth medium of primary monolayer cultures of bovine fetal pancreatic islet cells grown with usual and increased (300 mg%) glucose content. The latter led to an enhanced insulin secretion. The results of cytological study demonstrated a definite interrelationship between the mitotic activity of culture cells and the intensity of insulin secretion into the medium.

Animals↗

[Cell cultures obtained using collalytin from the pancreases of cattle fetuses].

The authors present morphological characteristics of primary monolayer cultures prepared from the pancreas of bovine fetuses. Combined treatment with trypsin and collalytine solutions (a preparation with collagenase activity) was used for dispersion of the tissue of the pancreas. Numerous epithelial cells corresponding by morphofunctional characteristics to beta-cells of the islets of Langerhans were contained in be cultures obtained; an aldehyde-fuchsin-positive granularity was revealed in the cytoplasm of these cells. Degranulation of these cells occurred under the effect of an increased glucose concentration in the nutrient medium.

Animals↗