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Biomedical subjects

J Ormos

Publications and source records attributed to J Ormos.

At least 73 records · Page 4Linked to original sources
PubMed1983

Tubulointerstitial inflammation, cast formation, and renal parenchymal damage in experimental pyelonephritis.

Some basic changes in experimental pyelonephritis were studied by transmission and scanning electron microscope. Initially, bacteria settled and multiplied in capillaries and venules. Leukocytes first marginated and then escaped from the capillaries, particularly to the wide peritubular interstitium. After opening the tubular basement membrane, the infiltrating leukocytes were immediately localized in the tubular wall between epithelial cells but were never seen between the epithelial cells and the underlying basement membrane. The inflammatory cells seemed not to be able to pass through the tight junctions of the nonnecrotic tubular epithelium. As a consequence of severe inflammatory injury, the tight junctions exhibited alterations of intermediate junction type. Where circumscribed necrosis of the tubular walls occurred, leukocytes appeared in the lumen. Thus, pus casts originated from these sites, apparently as drainage of interstitial abscesses. The secondary/regressive and regenerative/tubular changes were similar to those occurring after various tubular lesions.

Abscess↗
PubMed1983

Renal amyloidosis. Histological differentiation based on chemical types compared to Reimann's classification.

13 cases of renal amyloidosis were reclassified on the basis of the chemical types of the major amyloid fibril proteins. The classification (primary, secondary) depending on the absence or presence of a coexisting disease was found not to correlate with the classification based on the chemical types (AL, AA). It is concluded that in association with a disease capable of inducing amyloidosis amyloid of type AA does not necessarily appear. The deposited amyloid may be of AL type. No difference of decisive importance between the AL and the AA type was observed concerning the tissue distribution of the amyloid within the kidney. With respect to the cause of death, however, a significant difference was found between the chemical types. In amyloidosis of AA type, the cause of death was always renal insufficiency, whereas in the cases of AL type cardiac or hepatic insufficiency led to death. Differentiation of the types of amyloid proteins has gained practical importance, as it offers the possibility of selective therapeutic approaches. Their routine differentiation is possible with the potassium permanganate method.

Aged↗
PubMed1982

Activity of glucose-6-phosphatase in regenerating tubular epithelium in rat kidney after necrosis induced with mercuric chloride: a light and electronmicroscopical study.

The activity of glucose-6-phosphatase was investigated in the renal proximal tubules of male albino rats after necrosis induced with mercuric chloride. Between the 3rd and 14th days an active zone could be observed in the inner cortex, which in the control animals was inactive. As regeneration progressed, the number of regenerating active tubules in the cortex increased, and in the 4th week activity approached that of the controls. Ultrastructurally, the enzyme was localized in the endoplasmic reticulum and nuclear envelope and sometimes even in necrotic cells. It appeared again in the regenerating cells on the 4th day. Our histochemical results complement the published biochemical results on the analysis of tissue homogenates localizing the changes of enzyme activity. From this comparison we conclude that glucose-6-phosphatase may take part in either glucose degradation or gluconeogenesis, but whereas gluconeogenesis also occurs in the first part of the proximal tubules in the normal kidney, the enzyme may play a role in glucose consumption only under pathological conditions.

Animals↗
PubMed1982

Congenital hepatic fibrosis with polycystic disease of the kidneys.

Three cases involving simultaneous occurrence of congenital hepatic fibrosis (CHF) and polycystic kidneys (PCK) are reported. In two infantile forms hepatic fibrosis accompanying polycystic renal lesion was revealed only on autopsy; the third patient has been kept under observation for seven years. Emphasis is laid on the importance of early diagnosis if serious complications are to be prevented. The pathogenesis of the disease is discussed on the basis of light and electron microscopic investigations of repeatedly taken liver and kidney biopsy material.

Biopsy↗
PubMed1981

Histochemical studies of oxidoreductases in rat kidney regenerating after mercuric chloride injury.

The activities of succinic dehydrogenase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and cytochrome oxidase, representatives of the tricarboxylic acid cycle, pentose phosphate pathway, glycolysis and terminal oxidation, respectively, were investigated after necrosis induced with mercuric chloride. 24 hours after the administration of mercuric chloride, the activities of all four enzymes were decreased in the necrotic proximal tubular segments. By the third day of regeneration the activities had decreased or disappeared in all three portions of the necrotic proximal tubules as compared to the 24-hour situation, but they remained constant in the distal tubules; the activity of G6PDH was rather increased. Between the 5th and 12th days the activities gradually increased in the regenerating proximal tubules, while the G6PDH activity of the distal tubules remained elevated, and by the 3rd to 4th week the activities were the same as those in the control animals. Our histochemical results complement the earlier biochemical results of analyses of tissue homogenates localizing the changes of enzyme activity. The histochemical studies suggest that the non-necrotic parts of the nephron contribute to the supplies of energy and substances to the regenerating cell.

Acute Kidney Injury↗
PubMed1980

[Light and electron microscopic study of the seminiferous tubules in experimental malacoplakia].

Behaviour of the epithelium of seminiferous tubules and interstitial tissue was studied in malacoplakia induced by administration of an extract of E. coli. Necrosis of the epithelium of seminiferous tubules developed immediately and it was replaced by granulocytes, and histiocytes, phagocytizing both, bacterial extract administered and disintegrated cells. Tunica propria was thickened by inflammatory cells. Hansemann cells were observed not only in the interstitium but between the layers of the tunica propria and on the place of the necrotized epithelium of the seminiferous tubules. Although Sertoli cells possess phagocytizing activity it could not be proved, that Hansemann cells are taking their origin from them.

Animals↗
PubMed1979

Renal cortical tubules in experimental malakoplakia. Phagocytic alteration of tubular epithelium.

Intrarenal injection of a crude E. coli extract (endotoxin-antigen-complex) induced malakoplakia in rats. Beside the granulation tissue the proximal tubular epithelium showed a strong phagolysosomal response--especially in two-three weeks--, thus becoming very similar to the Hansemann cells of the malakoplakia granulation tissue. This malakoplakia alteration of the epithelium if very severe sometimes led to necrosis or it was segregated inside the epithelial cells. Later on an atrophy of the tubules developed similar to the atrophy of different etiology, but the remaining cells often contained a striking number of residual bodies. It is suggested that the tubular granulated cells of megalocytic interstitial nephritis regarded as identical with renal cortical malakoplakia also have a tubular epithelial origin.

Acid Phosphatase↗
PubMed1979

[Transformation of the epithelial cells of the kidney tubules in experimental malacoplakia].

As an effect of administration of the extract of E. coli in the kidney of rats phagolysosomal reaction has been observed, not only in the granulomatous tissue characteristic of malacoplakia, but in the epithelial cells of the proximal tubules. The latter became similar to the histiocytes of malacoplakis i.e. Hansemann's cells. The transformation of the tubular epithelium in severe cases of malacoplakia was followed by necrosis. In a later phase tubular atrophy came into being, which did not differ from the atrophy caused by other agents, although epithelial cells contained numerous residual body. Authors believe, that granular tubular cells of megalocytic interstitial nephritis--regarded as malacoplakia of the renal cortex--originate from tubular epithelium.

Animals↗
PubMed1979

[Regeneration of the proximal kidney tubules after sublimate-induced necrosis in the rate. Scanning electron microscopic studies].

Necrosis of the proximal tubules of the kidney in white rats has been produced by a relative small doses (1,5 mg/kg) of sublimate. Necrosis of the epithelial cells and their regeneration was studied during 10 days by scanning electron microscopy. Parallelism of the various regressive and regenerative processes was noted, attention was paid to the correlation existing between them. Periodicity of normal and necrotic segments was also observed. As a sequal of the necrosis the basement membranes became denuded, later in the first period of the regeneration flattened epithelial cells--having no microvilluses--covered them. On the surface of the latter, in a very short period (several hours) gradually microvilluses, regular brush-border and interdigitation of the cells were formed. In 10-17 days the regenerated epithelium could hardly be distinguished by scanning electron microscopy from the normal one.

Acute Kidney Injury↗
PubMed1979

Regeneration of proximal tubules of the rat kidney following sublimate necrosis. A scanning electron microscopic study.

Necrosis of the proximal tubules of the rat kidney was induced by low (1.5 mg/kg) doses of sublimate. Epithelial necrosis and regeneration were followed by scanning electron microscopy for 10 days. Regressive and regenerative processes were observed simultaneously. The naked basement membrane is first invaded by flat epithelial cells lacking microvilli. Within a few hours microvilli appear followed by the formation of regular brush-border and interdigitations cells. After 7--10 days the newly formed epithelium cannot be distinguished from the intact one.

Animals↗
PubMed1979

Histochemical studies on peroxisomes in regenerating proximal tubules of the kidney.

Peroxisomes of the regenerating proximal tubules of the rat kidney were investigated after necrosis induced by mercuric chloride. Slices both for light and electron microscopic examinations were incubated in 3,3'-diaminobenzidine (DAB) medium. Peroxisomes were absent in the necrotic epithelium. They appeared on the fourth day of regeneration and later their number increased reaching the normal distribution in the fourth week. They seem to be needed for the functional differentiation of the proximal tubule cells during regeneration.

Animals↗
PubMed1979

Urinary osmolarity in late stage nephritis and nephrosis.

Urinary osmolarity was studied with the DDAVP test in 30 children in the late stage of glomerulonephritis or nephrosis syndrome, and in 12 control children. A restriction of the concentrating ability of the kidney was demonstrated in the cases accompanied by residual symptoms, in comparison to the healthy children and to the patients in lasting remission. In the cases examined histologically, tubular damage corresponding to the functional change could be demonstrated.

Adolescent↗