[Ultrastructural changes and regeneration of the endocrine apparatus of the human gastric mucosal glandular epithelium in patients with chronic erosive gastritis].

The aim of this investigation was to study the structure and regeneration of the endocrine apparatus of the human gastric mucosal glandular epithelium. Using electron microscopy, the mucosal biopsy specimens obtained from 14 patients with chronic erosive Helicobacter pylori-associated gastritis, were studied. The most pronounced changes were seen both in the numbers and ultrastructure of G- and P-endocrinocytes. The changes were detected in the nucleus structure, endocrine granule and polysome content, and he mitochondrial structure. The regeneration of the endocrine cells took place through the differentiation of the committed precursors via the "agranular" cell stage, transformation of the exocrine cells into the endocrine ones, and as a result of the formation of the epithelial cords on the erosion surfaces that consisted of the cells in diverse differentiation stages (from the undifferentiated to specialized cells of all the endocrine and exocrine types).

[Structural changes in the rat intestinal wall during starvation].

The aim of this study was to determine the effect of starvation on all the tunics of duodenum and rectum wall. The animals were 20 outbred albino rats; the control group comprised 4 animals. The animals were starved while the drinking regime remained unchanged. Material was obtained at days 3 and 6 of starvation and was studied using electron microscopy. The changes were detected in the structure of mucosa, submucosa, tunica muscularis and serosa. These structural changes were of similar nature in all the tunics and differed only by the degree of their severity. The most pronounced changes were observed in all the epithelial cell types (absorbing, goblet and endocrine) in both parts of the intestine. These included cell flattening, microvilli reduction and deformation, mucus production disturbances, destructive changes in the mitochondria (swelling, cristae reduction, vacuoles and myelin-like structures formation, disruption of both mitochondrial membranes).

Transcranial electrostimulation activates reparative regeneration and the insulin-producing function of pancreatic B-cells in alloxan diabetes in rats.

Studies on rats with experimental diabetes induced by administration of alloxan showed that transcranial electrostimulation of endorphinergic brain structures stimulates the regeneration of damaged beta-cells in pancreatic islets of Langerhans. This was identified on pancreatic sections stained with hematoxylin and eosin. De novo formation of small islets was noted, as evidenced by their regeneration from progenitor cells. After transcranial electrostimulation, islet beta-cells stained by the Gomori method showed recovery of granularity - a sign of insulin production. Application of an immunoenzyme method demonstrated recovery of blood insulin levels, the dynamics of increases in which showed a highly significant negative correlation with a decrease in blood glucose. These data led to the conclusion that the antihyperglycemic effect of transcranial electrostimulation in experimental alloxan diabetes results from reparative regeneration of beta-cells in islets of Langerhans with recovery of their insulin-producing function.

[Transcranial electrical stimulation activates the reparative regeneration and insulin-producing function of beta-cells in alloxan-induced diabetic rats].

In alloxan-induced diabetic rats, it was demonstrated that transcranial electrical stimulation of the brain endorphinergic structures activated the reparative regeneration of the damaged beta-cells of the Langerhans pancreatic islets. This was estimated on the histological sections of pancreas with hematoxylin-eosin staining. Several small newborn islets were found to originate from pancreatic progenitor cells. After transcranial electrical stimulation of insulin granules, beta-cells (Gomori's staining) were observed as an indication of the restoration of the insulin production. Correspondingly the increase of the blood insulin level was estimated by immune-enzyme method. The dynamics of the plasma insulin increase had a significant negative correlation with decrease of the blood glucose level. The glucose-lowering action of the transcranial electrical stimulation in alloxan-induced diabetic rats seems to be based on stimulation of the regeneration of damaged beta-cells with the restoration of their insulin production.

[Structure-functional changes in the rat pancreas after glucose injection].

Electron microscopic method was used to study the effect of hyperglycemia on the pancreas of albino rats (n = 20) after intraperitoneal administration of 40% glucose solution (daily, for 5 days). The data obtained suggest that repeated administration of glucose was accompanied by marked changes in the structure B-endocrinocytes, indicative of the increased secretion of the insulin. This resulted in the appearance of new small pancreatic islets, that consisted of B-endocrinocytes and acino-insular cells. Most frequently acinar-insular cells were located at the periphery of newly formed islets. The latter often had a symplast-type structural organization.

[Ultrastructure of endocrine cells in the dog pancreas].

Electron microscopy was used to study the cellular composition of dog pancreatic islets. Four types of endocrine cells were detected: A, B, D and PP. B cells were the predominant population within the islets. Differences in cellular organization of A and B cells were shown to be caused by the phases of the process of hormone synthesis. Insulin-containing secretory granules in B cells had a crystalloid structure, similar to that in B granules of insulin-containing cells in human pancreatic islets. In the exocrine portion of the pancreas, acino-insular cells were detected that simultaneously contained B granules and zymogen granules in their cytoplasm. It is suggested, that their presence is indicative of one of possible directions of pancreatic islet regeneration.

[Regularities of cytogenesis in the endocrine gastroenteropancreatic system in vertebrates]. / Zakonomernosti tsitogeneza éndokrinnoi gastroénteropankreaticheskoi sistemy pozvonochnykh.

This paper reviews the literature data and the results of authors' own investigations on cytogenesis of endocrine cells of gastro-entero-pancreatic (GEP-) system in vertebrate animals and man. In pancreas two groups of sources of endocrine cell development were distinguished including both intra- and extrainsular. In cytogenesis of mucosal endocrine cells in gastrointestinal tract (GIT) the major role belongs to the stem cells which differentiate through the stage of committed precursors ("agranular cells"). Pancreas and GIT epithelium are characterized by the formation of endocrine cells from exocrine ones. The data presented provide the indication of the endodermal origin of endocrine cells of GEP-system.

[Differentiation of human pancreatic endocrine cells in the period of fetal development]. / Differentsirovka éndokrinotsitov podzheludochnoi zhelezy cheloveka v plodnyi period razvitiia.

The stereological analysis of electron micrographs of pancreatic endocrine cells (A and B) obtained from human fetuses at gestational months 4 to 7 was performed to assess the volume densities of membranous organelles (mitochondria, rough endoplasmic reticulum, Golgi complex), polysomes and secretory granules. The differences were established in the ratios of the volume densities of organelles and secretory granules in the process of differentiation. The morphometric characteristics of total A- and B-cell populations as well as the quantitative data on the structural organization of endocrine cells at various stages of differentiation are presented.

[Cellular level of the body adaptation to the environmental exposure in the large industrial city (Saint-Petersburg)]. / Kletochnyi uroven' adaptatsii organizma k vozdeistviiu okruzhaiushchei sredy krupnogo promyshlennogo goroda (Sankt-Peterburg).

By methods of light and electron microscopy structural disturbances of heart, kidneys, liver and pancreas were studied in rats pups who were born and kept for a year at kindergartens of city districts diverse in level of environmental pollution (air and soil). The content of micronuclei in epitheliocytes of oral mucosa in 5-6 ys old children from the kindergartens was controlled in order to detect chromosome aberrations. The examination of morphofunctional state of the organs studied and cells containing micronuclei carried out in different districts of the city allowed to reveal correlation between disorders studied and the level of environmental pollution.

[Differentiation and cytogenesis of endocrine elements of the rat duodenum in ontogenesis]. / Differentsirovka i tsitogenez éndokrinnykh élementov dvenadtsatiperstnoi kishki krysy v ontogeneze.

Duodenal endocrine apparatus was studied in rat during individual development using electron microscopy. Endocrinocyte differentiation was demonstrated to occur in embryonic period and it is characterised by fast cytotype number growth. During embryogenesis processes of endocrinocyte differentiation occur more intensely than in adult animals which is manifested by higher incidence of different types of incretory elements in embryos. By the moment of birth EC-, L-, S-, D-, D1-, P and I-cells can be identified in the duodenal epithelium at different stages of differentiation as well as "mixed" exo-endocrine cells. The presence of transitory cellular forms from agranular elements up to mature differentiated endocrinocytes and "mixed" exo-endocrine cells reflects cytogenetic processes in population of endocrine cells and allows to consider duodenal epithelium both structurally and functionally as a tissue with common histogenetic basis.

[Endocrine apparatus of the epithelium of the appendicular mucosa (the appendix-- an endocrine gland, functioning in the embryonal period?]. / Endokrinnyi apparat épiteliia slizistoi obolochki cherveobraznogo otrostka cheloveka (cherveobraznyi otrostok--éndokrinnaia zheleza, funktsioniruiushchaia v émbrional'nyi period?)

Based on the concept on gastroenteropancreatic system, endocrinocytes of which are diffusely scattered throughout the digestive tract epithelium and are found in pancreatic islets, an analysis of endocrine apparatus of epithelium in human appendicular mucosa was performed at different stages of ontogenesis. The response of appendicular endocrinocytes to clinical pathology of both this organ and the entire organism was studied. On the base of the analysis of the appendix function from morphological view, the authors proposed a hypothesis postulating it to be an organ equal to an actively functioning endocrine gland and its unique role on early stages of embryogenesis.

[Body adaptation to the action of ecological factors at the cellular and subcellular levels]. / Adaptatsiia organizma k deistviiu ékologicheskikh faktorov na kletochnom i subkletochnom urovniakh.

Chemical and physical factors action on different organ tissues in animals were examined by light and electron microscopy. Comparison of the action of the agents mentioned showed, that in both cases the totality of compensatory-adaptive reactions depends on heterochronism of the changes that develop in organelles, cells and tissues and is determined by individual sensitivity of animals and asynchronism of the development of primary reactions at the organelle level, which accounts for mosaic pattern of structure of cells, comprising the tissues. It is established that in cells energy metabolism is disturbed first due to mitochondria damage irrespective of the unfavourable factor. The phenomenon of tissue adaptation is considered as an integrative process that occur within the ontogenesis. The entire process of tissue adaptation at the level of cells and organelles is divided on 5 stages according to structural changes demonstrated while exerting the influence. This allows to estimate both direction and significance of the damage and tissue compensatory and reparative capacity.

[The endocrine apparatus of the epithelium of the gastric mucosa in the steppe turtle (Testudo horsfieldi)]. / Endokrinnyi apparat épiteliia slizistoi obolochki zheludka stepnoi cherepakhi.

Endocrinocytes of stomach mucosal epithelium were studied using light and electron microscopy in steppe turtle (Testudo horsfieldi). Endocrine apparatus of stomach in turtle was shown to retain the pattern characteristic for other representatives of vertebrates. Difference is observed in endocrinocytes localization. The latter are accumulated predominantly in upper and middle regions of glandulae, sometimes being encountered also in surface epithelium. 8 cell types were identified according to size and structure: EC, G, D, D1, A-like, X, ECL and P. Relating to glandular lumen, endocrinocytes are divided into elements of closed (D, D1, A-like, ECL, X, and P) and open types (EC, G). In the latter apico-basal differentiation is expressed in cytoplasmic structure. Endocrinocytes are unevenly distributed throughout the stomach regions. Greatest number is concentrated in pyloric part, EC-cells being the predominant type. EC, ECL-cells and less A-like and D-cells are mostly encountered in fundal part, EC, G and single D and P cells--in pyloric part and, agranular and exo-endocrine cells--in both stomach parts.

[The cytogenesis and differentiation of the epithelial endocrinocytes of the large intestine in hens and rats in ontogeny]. / Tsitogenez i differentsirovka éndokrinotsitov épiteliia tolstoi kishki kur i krys v ontogeneze.

Cytogenesis and differentiation of epithelial endocrinocytes were studied by methods of histochemistry and electron microscopy in large intestine of hen and rat in the course of their individual development. In the embryogenesis processes of cellular and organospecific differentiation occur in epithelium of these animals large intestine, which is proved by early revealing of endocrinocytes, when epithelial plast is yet undifferentiated. Growth of differentiation in hen and rats is marked on day 19-21 of postnatal embryonal development. In postnatal ontogenesis endocrine apparatus achieves definitive state by day 5 in hen and day 20 in rats. Argentaffin cells are the leading sub-population, which reflects the importance of serotonine they produce in realizing regulatory reactions of the organism. Slightly differentiated cells are the source of endocrinocyte cytogenesis.

[The ultrastructure of the pancreatic endocrinocytes of human fetuses in postmortem autolysis]. / Ul'trastruktura éndokrinotsitov podzheludochnoi zhelezy plodov cheloveka pri posmertnom autolize.

The method of electron microscopy was used to study the morpho-functional state of pancreatic islands of human fetuses at different terms (10-54 h) after clinical death. Within the periods of time in question the island secretory cells preserve the structure characteristic of each type (B, A, D). The development of symptoms of postmortem autolysis of the pancreatic island is not a chaotic fleeting physico-chemical reaction and is characterized by a definite sequence of cytological changes of endocrinocytes. A conclusion is made that cadaveric material of the pancreas is good for preparing the pancreatic island culture for using it in the following tissue substituting therapy of patients with diabetes mellitus.

[Structure and cytophysiology of gastric endocrine gland cells after repeated administration of testosterone propionate]. / Stroenie i tsitofiziologiia éndokrinotsitov zhelez zheludka pri mnogokratnom vvedenii testosteron-propionate.

By means of light, electron microscopy and morphometry methods contents and structural organization of endocrinocytes have been investigated in gastric glands of rats, to whom testosterone propionate has been injected for 5, 10, 15, 20 days. The hormone produces certain stimulating effect on the endocrine apparatus function. During the first stages of the experiment most of the endocrinocytes are at the state of active secretion; this is testified as a decreasing composition of histochemically revealed cells in epithelium and their degranulation. During the following stages the process of synthesis is activated in the cells and their amount increases. Appearance of numerous agranular, poorly differentiated endocrinocytes and exo-endocrine cells demonstrates certain intensification of cytogenesis of endocrinocytes in the gastric epithelium. The changes observed are considered as adaptive, directed to stabilize homeostasis, when the hormonal balance is disturbed.

[Endocrine apparatus of the duodenal epithelium in chronic gastroduodenitis in children]. / Endokrinnyi apparat épiteliia dvenadtsatiperstnoi kishki pri khronicheskom gastroduodenite u detei.

Ultrastructural organization of the endocrine apparatus of the duodenum in children suffering from chronic gastroduodenitis was studied on 15 biopsies, and its involvement in pathological process is shown. Signs of the functional activity enhancement on the one hand and those of damage on the other hand are observed in the cells. Apart from that, poorly differentiated endocrine cells and "mixed" endocrine and exo-endocrine cells which can be considered as a manifestation of endocrine elements recovery appear in the duodenal epithelium.

[Microscopic organization of epithelial endocrine cells of the gastrointestinal tract mucosa in lower vertebrates. II. Epithelial endocrine cells of the duodenum of the common frog]. / Mikroskopicheskaia organizatsiia éndokrinnykh kletok épiteliia slizistoi obolochki zheludochno-kishechnogo trakta nizshikh pozvonochnykh. II. Endokrinnye kletki épiteliia dvenadtsatiperstnoi kishki travianoi liagushki.

The endocrine epithelium cells of the frog duodenum mucosa were studied using light and electron microscopy. In the intestinal epithelium endocrine cells are distributed among enterocytes all over the surface of mucosa. The greatest quantity of them is observed in the intestinal part in the proximity of the stomach. Six types of endocrine cells are identified on the basis of their granular structure and size. Some differentiation in submicroscopic organization of endocrine cells depending on their functional condition is defined.