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PubMed1976

The metabolism-dependent maintenance of cell volume and ultrastructure in slices of Morris hepatoma 3924A.

The changes in water and electrolyte content of slices of Morris hepatoma 3924A induced by various conditions of incubation have been compared with the ultrastructural appearance of the tissue. Incubation at 1 degrees led to an increase of water, Na+, and Cl- content and to a loss of K+. There was simultaneous increase in size of the cells and intercellular spaces, loss of junctional complexes, increase in the number of microvilli, and fragmentation and dilation of the cytocavitary network. Subsequent incubation at 38 degrees in oxygenated medium led to a substantial reversal of all of these changes of composition and structure, which was well advanced within 10 min and largely complete by 60 min. The presence of 20 mM glucose in the medium somewhat enhanced the degree of recovery. A reduction of cell volume and intercellular spaces was evident both from the electron microscopic observations and measurements of the volume of inulin distribution. The presence of ouabain inhibited the net accumulation of K+ and much of the Na+ extrusion, but permitted about 50% of the net extrusion of water (accompanied by Na+ and Cl-) and had little effect on the ultrastructural recovery. The presence of glucose increased the resistance of volume and structural recovery of ouabain without releasing the inhibition of K+ accumulation. A marked feature of the recovering tissues was the Golgi apparatus, which assumed an appearance suggestive of increased activity when water extrusion was active. In slices using only endogenous substrate, cyanide and (to a lesser extent) oligomycin greatly inhibited the recovery of volume and structure. The presence of glucose permitted some recovery in the presence of cyanide. The control of cell volume in hepatoma 3924A appears to involve two separate components of water transport, one of which is sensitive, and one insensitive to ouabain. The ouabain-insensitive component appears to be especially related to the recovery of cell ultrastructure after incubation at 1 degrees, to be more sensitive to paucity of adenosine 5'-triphosphate, and to proceed by secretion of water, Na+, and Cl- into vesicles that fuse with the Golgi apparatus. This mechanism may be related to that for bile secretion in normal liver. The ouabain-sensitive component of water transport is a function of the mechanism for the coupled transport of Na+ and K+.

Anaerobiosis↗
PubMed1991

[Blood gastrin and ultrastructure of gastrin-producing cells in chronic gastritis with secretory insufficiency].

The content of basal gastrin and ultrastructure of gastrinproducing cells was studied in 81 patients showing chronic gastritis with secretory insufficiency. The highest level of gastrin was revealed in the blood of patients with diffuse atrophic gastritis, moderately increased--focal atrophic gastritis. The blood gastrin was reduced in patients with antral gastritis. A study of the ultrastructure of gastrinproducing cells revealed their high functional activity in diffuse atrophic gastritis and a moderate in focal atrophic gastritis. Changes of the gastrin level and ultrastructure of gastrinproducing cells should be considered in the choice of treatment methods.

Adult↗
PubMed1991

[Ultrastructural changes in rectal mucosa cells in experimental Escherichia infection].

Ultrastructural changes of rectum epitheliocytes and cells of lamina propria were studied at the period from 15 minutes to 2 days after inoculation using the model of experimental escherichiosis. The results obtained allow to determine the correlation of ultrastructural changes and the data of morphometric analysis. Ultrastructural peculiarities were determined of the rectum cells and the different cell populations were studied during infection's process.

Acute Disease↗
PubMed1976

[Ultrastructural changes in the central nervous system of monkeys in poliomyelitis].

The ultrastructure of cells of the central nervous system of Rhesus monkeys in experimental poliomyelitis caused by virus of poliomyelitis Type 3 was studied. It was found out that the virus of poliomyelitis was localized in nerve cells, astocytes, oligodendrocytes, the endothelium of capillaries and macrophages. This justifies the conclusion that pathological changes in the cells referred to the above result from reproduction of the virus therein. Ultrastructural changes in infected cells are divided into three stages: the first stage corresponded to eclipse-phase of infection; the second -- to the period of reproduction of the virus and composition of viral particles; and the third -- to the period following the escape of the virus from the cell. A definite combination of nonspecific changes in organoids of various cells with specific viral inclusions makes the ultrastructural picture of cells in poliomyelitis sufficiently characteristic for differential diagnosis. Pathogenesis of the developing lesions is discussed.

Animals↗
PubMed1991

Ultrastructural studies on dermis from prolidase deficient subjects.

Ultrastructural analyses were performed on clinically normal skin from forearm and/or femoral regions of five subjects, all excreting high levels of gly-pro dipeptides into the urine and exhibiting very low prolidase activity on hemolyzed erythrocytes. In both regions, the overall organization of the dermis was normal. Stereological analysis, however, showed that collagen volume density was reduced when compared to that of age-matched controls. Collagen fibrils did not show ultrastructural alterations, but they were distributed into a higher number of small bundles, and their diameters shifted towards lower values compared to age-matched controls. The elastin volume density was slightly reduced in the patients, especially in the femoral areas. In both forearm and femoral dermis, elastin fibers were significantly more numerous and smaller than in controls. Furthermore, elastin fibers were apparently normal in the forearm dermis, whereas appeared polymorphic and cribriform in the femoral skin. The results focused on the importance of efficient proline re-utilization for normal collagen and elastin synthesis and deposition. The differences between femoral and forearm skin regions from both clinical and ultrastructural points of view, may depend on mechanisms that regulate circulation and, possibly, on other factors which modulate the phenotypic expression of mesenchymal cells.

Adult↗
PubMed1990

[Ultrastructural study of moniliformin-induced lesions on the myocardium of rats and mice].

Effects of moniliformin on the ultrastructure of the myocardium of mice and rats were studied. Mice were given moniliformin orally at the dosage of 29.46 mg/kg. One hour later lesions of the mitochondria of the myocardial cells were found which became more severe 2-3 hours later. Ultrastructural lesions were also observed in the myofibrils and sarcolemma. Rats were given moniliformin orally at the dosage of 6 mg/kg once daily for 56 days. Lesions of the mitochondria and myofibrils were relatively mild. Myocardiac specimens taken 21 days after toxin administration, lesions of the sarcolemma became more obvious. Various amounts of collagen were produced by the myocardiac cells. These moniliformin-induced lesions were similar to the ultrastructural changes in the myocardium of patients with Keshan disease. Our findings indicate that there may be a close and important relationship between moniliformin intoxication and Keshan disease.

Animals↗
PubMed1991

Ultrastructure of developing Isospora suis in cultured cells.

The ultrastructure of Isospora suis sporozoites, type-1 meronts, and type-1 merozoites was examined, using transmission electron microscopy of infected cultured cells. The ultrastructure of sporozoites and type-1 merozoites was similar. Each possessed trimembranous pellicles, subpellicular microtubules, a conoid, anterior and posterior polar rings, rhoptries, micronemes, a single vesicular nucleus, tubular mitochondria, Golgi complexes, ribosomes endoplasmic reticula, inactive micropores, amylopectin bodies, lipid bodies, dense bodies, and crystalloid bodies. Merozoites were produced by endodyogeny. Ultrastructural events associated with merozoite production by type-1 meronts are described.

Animals↗
PubMed1990

[Endocrine cells and Malpighian epithelium. Merkel-type cells? Immunohistochemical and ultrastructural study].

This study was devoted to a peculiar population of argyrophilic cells present among various stratified squamous epithelia. The purpose of the study was to determine the distribution and the nature of these argyrophilic cells, and to reappraise their degree of analogy with the Merkel cells of epidermis. Examples of squamous epithelia from skin, exocervix, anal canal and dermoid cyst of ovary were investigated using histochemical, immunohistochemical and ultrastructural techniques. Melanin-containing cells as well as peculiar argyrophilic cells were revealed in each series of specimens. These peculiar argyrophilic cells expressed EMA, chromogranin A and NCL-5D3 (cytokeratins 19, 18, 8) immunoreactivities. By contrast, they were serotonin negative. An intense staining for EMA was observed. These cells were obviously endocrine cells. Ultrastructural studies confirmed the presence of endocrine cells within the anal canal and the exocervix; moreover, in anal canal, some of these cells appeared to have contacts with a nerve terminal. Through the epidermis, these cells can only correspond to Merkel cells, because of their chromogranin positivity. Throughout other squamous epithelia, this population of endocrine cells (serotonin negative) bear some analogies with Merkel cells of epidermis. Their distribution, morphology, EMA immunoreactivity and ultrastructural appearance were reminiscent of those of the Merkel cells. They could be named Merkel-type cells. Additional studies, using other characteristic or specific markers of Merkel cells, are clearly required to determine the exact degree of analogy between these types of cells. Merkel-type cells could be largely distributed through stratified squamous epithelia from various tissues. They can be easily visualized by their strong EMA immunoreactivity and must be distinguished from Paget cells.

Endocrine Glands↗
PubMed1978

[Effect of long-term suppression and long-term stimulation of ACTH secretion on the ultrastructure of tanycytes[].

The ultrastructure of the tanycyte ependyma in males of Wistar albino rats (160--180 g of weight) was studied under experimental long-term suppression of ACTH secretion and its long-term stimulation. The former effect was accomplished by daily (for 8 days) intraperitoneal administration of dexamethasone phsophate; the stimulation of ACTH secretion was achieved by bilateral adrenalectomy. The long-term suppression of the hypophyseal adrenocorticotrophic function was followed by the ultrastructural markers of an increased transport and secretory activity in the tanycytes (mainly in beta-tanycytes, i. e. the ependyma lining floor of the third ventricle): the increased amount of microvesicles in the Golgi area and in the vicinity of the particular membranous cavity system (MCS, according to the authors' definition), the appearance of some figures of exocytosis, the elevated amount of lipid inclusions. On the contrary, the long-term stimulation of ACTH secretion was followed by the ultrastructural changes of the opposite character. The data obtained are in agreement with the previously established fact that there is a negative correlation between the tanycyte activity and the hypophyseal adrenocorticotrophic activity. It is supposed that this correlation is regulated by a feedback mechanism and attest to the involvement of tanycytes in the inhibitory control of ACTH secretion. A possible substrate inhibiting ACTH secretion by the tanycytes is discussed.

Adrenalectomy↗
PubMed1990

[The combined action of microwave radiation and hydrogen peroxide on the viability and ultrastructure of Pseudomonas aeruginosa cells].

The comparative study of the action of microwave radiation and hydrogen peroxide, as well as their combined action, on the viability and ultrastructure of P. aeruginosa cells has been made. The combined use of microwave radiation and hydrogen peroxide has been shown to decrease the viability of P. aeruginosa 1.5-2 times in comparison with the isolated action of each factor. The electron microscopic study of the ultrastructure of cells have shown the deterioration of the surface structures, nuclear and ribosomal apparatus of the cells under the isolated action of each of the above-mentioned factors or under their combined action. The morphological picture of these changes has proved to be different. The maximum changes in the ultrastructure of P. aeruginosa cells have been registered after the combined action of these bactericidal factors.

Colony Count, Microbial↗
PubMed1990

[Changes in hepatic ultrastructure and function following portal vein resection with a use of an internal shunt bypass].

Experimental studies on ultrastructural and functional changes of mitochondria were carried out using adult dog livers after portal vein resection with an internal shunt bypass. As a comparative study portal vein resection with an external shunt bypass was also carried out. A 10 cm long anti-thrombotic UK catheter was inserted into the portal vein as an internal shunt bypass (internal shunt group). Similarly, a catheter was inserted between the portal vein and inferior caval vein as an external shunt bypass (external shunt group). The time of portal vein shunt bypass was 2 hrs for both groups. During operations, the blood flow of the hepatic artery was blocked. After the bypass was installed, the hepatic artery and the portal vein were declamped. As a control experiment the hepatic artery was clamped without making a shunt bypass (non-shunt group). Left lateral lobe was resected from the liver prior to the shunt implant and then the right lateral lobe was removed 2 hrs after the declamping of the hepatic artery. Biochemical analysis on mitochondria isolated from the livers of the internal and the external shunt groups was carried out. Changes of mitochondrial ultrastructure were also studied using electron microscope. Changes in serum m-GOT and OCT activities were also examined. Essentially no changes were detected in phosphorylating capacities and ultrastructure of mitochondria of the livers obtained from either the external shunt group or the internal shunt group. However m-GOT and OCT activities in the serum were definitely elevated in the external shunt group of animals compared to those in the internal shunt group of animals. This suggests that the permeability of hepatic mitochondrial membranes in the external group of animals was changed probably due to hypoxia. From these results we recommended the application of the internal shunt bypass for hepato-biliary surgery combined with the resection of the portal vein.

Adenosine Triphosphatases↗
PubMed1990

Solitary malignant Schwannoma: clinical aspects, immunohistochemistry and ultrastructure.

Solitary malignant Schwannoma is a rare tumor derived from cells of the nerve sheath, the Schwann cells. During the past 6 years we have treated six patients with this tumor, four males and two females ranging in age from 18 to 69 years. Five of them had their tumors located on the trunk, which is associated with a bad prognosis. In four of the six patients ultrastructural examination played an important role in making the diagnosis of malignant Schwannoma. Light microscopy alone is insufficient because the spindle-shaped cells growing in fascicles often closely resemble other sarcomatous tumors. Ultrastructural typical findings of Schwannomas are cytoplasmic processes, intercellular junctions and basal lamina. Surgery was the sole treatment in three patients. One patient only received chemotherapy because of disseminated disease. The other two were treated with surgery combined with radiotherapy. Four patients developed distant metastases for which chemotherapy was given, but all patients died within 3 years after their initial treatment. Only two patients are free of disease 56 and 72 months after treatment. Solitary malignant Schwannoma is a tumor with a grave prognosis, for which ultrastructural and immunohistochemical examination plays an important role in order to establish the diagnosis.

Adult↗
PubMed1990

[Ultrastructural diagnosis of neuroendocrine tumors using fine needle biopsy].

Ultrasonic-guided fine-needle-biopsies of primary pancreatic tumours or liver metastasis were performed in 13 patients with neuroendocrine tumours of the gastrointestinal tract (5 carcinoids, 3 gastrinoma, 1 PPoma, 1 calcitoninoma, 1 insulinoma, and 2 non-functional tumours). Specimens obtained were examined on the light- and electronmicroscopic level. In all cases ultrastructural examination sufficiently revealed the correct diagnosis, due to the presence of cytoplasmic neuroendocrine granules within the tumour cells. Additionally performed immunocytochemical investigations at the ultrastructural level enabled the discrimination of gastrinomas, insulinomas, and PPomas. In contrast, light-microscopic examination was less sensitive for tumour classification. It is concluded that ultrastructural investigation of fine needle biopsies represents a valuable method to sufficiently discriminate neuroendocrine neoplasms.

Adenoma, Islet Cell↗
PubMed1990

[Ultrastructure of the epithelial cells of the duodenum at the early stages of experimental Escherichia infection].

Ultrastructural changes of duodenal epitheliocytes were studied at the period from 15 minutes to 24 hours after inoculation using the model of experimental esherichiosis. The results obtained allow to determine the succession of ultrastructural changes and dynamics of adenylate cyclase activity of epithelial cells, involvement of endocrine cells in the pathological process. Combination of the certain morphological and cytochemical reactions and their dynamics allowed to make conclusions about typical ultrastructural changes in epitheliocytes at the early stages of experimental esherichiosis.

Adenylyl Cyclases↗
PubMedDate not supplied

Ultrastructure of hepatocellular tumors.

The lesions that appear during hepatocarcinogenesis can be separated into morphologically distinct entities, which have been arranged into sequences believed to represent stages in carcinogenesis. Similarly, the primary and transplantable hepato-cellular carcinomas (HCC) can be arranged into a sequence of stages believed to represent the progression toward the ultimate cancer cell. Separation of morphological entities has been most successful in rat liver. Ultrastructural studies differentiate between lesions derived from hepatocytes and those originating in other cellular components of the liver. They show that there is variability and divergence in the structure of cellular organelles in the early stages of carcinogenesis, that there is simplification of cellular structure and of organelles during the progression of HCC, and that qualitative changes specific for cancer cells do not exist. Toxic changes associated with the process of carcinogenesis are loss of stacks; wrapping of cisternae around mitochondria; dilation, denudation, and vesiculation of cisternae; increase of autophagy; depletion of glycogen, and enlargement of nuclei and nucleoli. Early changes are storage of glycogen and hyperplasia of smooth endoplasmic reticulum. Subsequent alterations are increased variability in the size, shape, and structure of mitochondria and in the structure of endoplasmic reticulum, including the appearance of fingerprints. A transient stage recognizable by storage of lipid may represent a degenerative process. Ultrastructural characteristics of basophilic cells such as abundance of free ribosomes and absence of glycogen and of smooth endoplasmic reticulum suggest that they may be a stage in the formation of HCC. Progression of HCC is associated with a decrease in the number and size of mitochondria, reduction of mitochondrial cristae, decrease in the number and complexity of microbodies, reduction of the tubulovesicular form of smooth reticulum, accumulation of free ribosomes, and increase of the granular component and condensation of the fibrillar component of nucleoli. Various types of nuclear inclusions reflect the increased mitotic rate of the neoplastic tissue. Changes of the cellular surface are believed to be associated with the ability of the cells to invade and metastasize. Future investigations will require the use of single doses of potent carcinogens, application of morphometric methods at the ultrastructural level, and acceptance of primates as models for human hepatocarcinogenesis.

2-Acetylaminofluorene↗
PubMed1990

[Ultrastructural study of fibrosarcoma].

Ultrastructure of 9 cases of fibrosarcoma was observed and compared with that of fibrous connective tissue of 4 human embryos and 9 cases of spindle cell sarcoma, including 3 each of leiomyosarcoma, neurofibrosarcoma and dermatofibrosarcoma protuberans. Ultrastructurally, fibrosarcoma consisted of well-differentiated fibroblast-like cells, poorly differentiated fibroblast-like cells (embryonic fibroblast-like cells), myofibroblast-like cells and primitive mesenchymal cells. It is suggested that fibrosarcoma may arise from primitive mesenchymal cells which are capable of differentiating into fibroblast and myofibroblast. There were two special cases of fibrosarcoma in this series. One was a congenital fibrosarcoma with ultrastructure resembling adult and the other was a sarcoma of myofibroblast. Diagnosis and differential diagnosis between fibrosarcoma and leiomyosarcoma, neurofibrosarcoma, dermatofibrosarcoma protuberans are discussed.

Adolescent↗
PubMedDate not supplied

[The differentiation of Opisthorchis eggs by the ultrastructure of their outer membranes].

Using a TESLA-BS-300 scanning electron microscope, the ultrastructure of the outer membranes of oocysts of 8 opisthorchis species (Opisthorchis felineus, O. viverrini, O. geminus, Clonorchis sinesis, Amphimerus anatis, Metorchis albidus, Pseudamphistomum truncatum, Erchoviorchis lintoni) belonging to 4 subfamilies, as well as that of O. felineus oocysts of various geographical isolates (from the Ukraine, the Volga region, West Siberia, Kazakhstan) have been investigated. The nature of the ultrastructure of the membranes differs from species to species and can be used for the differentiation of opisthorchis oocysts. Marked differences have been observed in different opisthorchis subfamilies (Opisthorchinae, Metorchinae, Pseudamphistominae, Pseudamphimerinae). The membrane ultrastructure was not significantly different in O. felineus oocysts from various geographical isolates, however, there are some distinctions in the size of oocysts and the form of apical thorns and opercular endings. The work has been done within the framework of the international scientific cooperation between the E. I. Martsinovskiĭ Institute of Medical Parasitology and Tropical Medicine, USSR Ministry of Public Health and the Institute of Parasitology, the Czechoslovakian Academy of Sciences.

Animals↗
PubMed1990

Involution of human fetal Leydig cells. An immunohistochemical, ultrastructural and quantitative study.

The testes of stillborn fetuses (from 13 to 28 weeks of gestational age), fetuses born alive (from 29 weeks of gestational age) who died a few days later, and infants dying 1 to 8 months after birth were processed for light and electron microscopy. Paraffin-embedded material was stained with the avidin-biotin peroxidase complex (ABC) method for immunohistochemical detection of testosterone (T) in order to quantify the age-related changes in the number of T-positive interstitial cells. This number decreased progressively from the 24th week of gestation up to birth and remained unchanged up to the second month of postnatal life. During the third month of age, the number of T-positive cells rose markedly but fell again from the fourth month to the end of the study. The ultrastructural study revealed the following types of interstitial cells at all ages studied: fibroblast-like cells, myofibroblast-like cells, developed fetal Leydig cells, degenerating fetal Leydig cells and infantile Leydig cells with a multilobed nucleus and focal cytoplasmic accumulations of smooth endoplasmic reticulum and lipid droplets. Quantitative ultrastructural studies revealed that the changes in the number of fetal Leydig cells with age were similar to those found in the number of T-positive cells although, for each age studied, absolute values were higher in the ultrastructural study. The number of infantile Leydig cells increased with age.

Aging↗