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Biomedical subjects

W Romen

Publications and source records attributed to W Romen.

At least 55 records · Page 3Linked to original sources

[Diabetic glomerulosclerosis: current status of its morphology and pathogenesis (author's transl)].

The diabetic glomerulosclerosis as a consequence of the abnormal metabolic state is characterized by an uniform thickening of the glomerular basement membrane (GBM) and an augmentation of the mesangial matrix. Both alterations begin already few years after the onset of the diabetes and are observed in all glomeruli to the same extent (=diffuse type). Later on, nodular deposits of glycoproteins are additionally found in the mesangium (=nodular type). Only these nodules are morphologically specific for the diabetic disorder. In association with both the diffuse and the nodular glomerulosclerosis, insudation of plasma can be seen in the afferent and efferent vessels and the glomerular capillary loops. The mechanism of the increase in the amount of GBM-material is not known, since contradictory data have been reported with regards to both the chemical composition and metabolism of the GBM in human and experimental diabetes. Some postulate that the abnormal deposition of GBM-mateiral is due to an excessive synthesis (anabolic disorder), others argue that a further decrease in the normally slow breakdown and disposal (catabolic disorder) might be responsible. This review presents the different pathogenetic concepts of the glomerulosclerosis and attemps to explain the possible causes for the current discrepancies.

Diabetic Nephropathies↗

[Benign hepatomata while taking oral contraceptives (author's transl)].

In recent years an increase in benign hepatomata during administration of oral contraceptives has been reported many times. A case is reported here of a 38-year-old woman who took such contraceptives for 8 years. The cardinal symptom was a tumor in the right upper quadrant of the abdomen. Laparotomy revealed several nodules in both lobes of the liver which could be almost completely removed by a wedge-shaped incision. Histologically a multicentric, focal nodular hyperplasia was present. Follow-up examinations after 24 months show no enlargement of the remaining tumor residues.

Adenoma↗

Carcinogenicity study of trichloroethylene by longterm inhalation in three animal species.

Pure trichloroethylene (tri), stabilized by an amine base, was administered by inhalation at 0, 100, and 500 ppm for 6 h/day, 5 days/week, for 18 months to mice, rats and Syrian hamsters of both sexes. No significant increase in tumor formation was observed in any species or dosing group, except in malignant lymphomas, which were increased in female mice in the following incidence rates: 9/29 (controls), 17/30 (100 ppm), and 18/28 (500 ppm). Whether or not this high occurrence of lymphomas, which is peculiar to this strain of mice (NMRI) has any relationship to tri-exposure, cannot be decided upon by the present experiment. It is concluded that from these findings no indication for a carcinogenic potential of pure trichloroethylene can be deduced.

Animals↗

Relationship of ploidy and chromatin condensation in the rat liver, moreover a comparison of the nuclear texture in sections and touch preparations.

In touch preparations and tissue sections from normal rat hepatocytes and alpha-amanitine- and actinomycin D-poisoned liver cells the extent of chromatin condensation relatively to the degree of ploidy and the chromatin distribution were studied by means of computer aided cytophotometry. It could be found, that the relationship of the condensed and decondensed chromatin is independent of the degree of ploidy and first of all dependent upon the intoxicant. Therefore, the extent of chromatin condensation can be utilized also in sections as additional parameter for automated cell screening.

Amanitins↗

Continent valve ileostomy.

2 years of experience with the sphincteroplasty in colostomy as well as intensive histological studies have shown that gastrointestinal smooth muscle can be autotransplanted without loosing functional or histological integrity. The following conclusions are based on experimental studies in dogs: (1) the sphincteroplasty technique can be successfully applied in ileostomy, and (2) the sphincteroplasty must, however, be combined with a pre-sphincter valve and an omega loop with Braun's anastomosis. The first clinical results confirm this concept.

Animals↗

Glomerular basement membrane turnover in young, old, and streptozotocin-diabetic rats.

Diabetic and senile glomerulosclerosis consists of thickening of the glomerular basement membranes (GBM) and augmentation of the mesangial matrix. The pathogenesis of these alterations is still controversial. Therefore, an in vivo study of the metabolism and the chemical composition of the GBM in streptozotocin-diabetic and old rats reported here was conducted: The turnover rate of the GBM, determined by the incorporation of labeled hydroxyproline, is prolonged in preparations from diabetic and aging rats. This can be explained by the decreased synthesis and delayed degradation of the GBM material found in both experimental groups. The biochemical analyses of the GBM revealed a higher content of hydroxylated amino acids, especially OH-lys, in the old and diabetic animals. The findings suggest that diabetic and senile glomerulosclerosis results from a prolonged turnover of the GBM and GBM-like material under the altered metabolic conditions investigated in this study.

Age Factors↗

[Very small ganglia as the cause of wrist pain].

In 10 patients with severe pain localised over the dorsal aspect of the lunate, the capsule of the wrist joint was exposed and fenestrated over the scapho-lunate ligament. In two cases flat ganglion cysts were found, too small to be palpated before surgery. In the other 8 cases without macroscopically visible changes, histologically, areas of mucoid degeneration and very small ganglion cysts could be seen in the capsule. All patients were pain free after surgery. It is concluded that very small intracapsular cysts in the area of the dorsal scapho-lunate ligament, the most common origin of ganglia, may irritate the posterior interosseus nerve which is located in this area.

Adult↗

[In vivo study of the effects of i.v. immunoglobulin therapy. Tissue distribution of native and enzyme-treated human immunoglobulin fractions given i.v. in man].

The tissue distribution of intravenously injected native and enzyme-treated human gammaglobulin has been investigated in human rectum mucosa. FITC-labelled antibodies to human gammaglobulin were used to locate the injected antibody preparation. Three hours after application of these different gammaglobulin-preparations no enrichment in the mucosa was found. Neither the native gammaglobulin nor the enzyme-treated gammaglobulin showed any concentration in the lamina propria of the large bowel mucosa or an intracellular enrichment in the epithel. This study shows that the quicker elimination of enzyme-treated gamma-globulin from the circulation cannot be explained by an intracellular increase.

Animals↗

Diffuse glomerulosclerosis--a dysfunction of the mesangium? A morphometric study of the rat's kidney.

The phagocytic capacity of the glomerular mesangial cells in 42 rats was inhibited by the prolonged injection of PVA. Morphometric evaluation of electron microscopic sections showed that this treatment leads to an accelerated thickening of the lamina densa of the glomerular basement membrane and of the mesangial matrix (early glomerulosclerosis). This suggests that a disturbance of lysosomal degradation can lead to glomerulosclerosis, and that the possibility of mesangial dysfunction should always be considered as a possible factor in the pathogenesis of all types of diffuse glomerulosclerosis.

Animals↗

[Continent colostomy through free transplantation of autologous colon muscles].

The study is concerned with a problem which is to a great extent still surgically unsolved, namely that of the incontinent hollow organ occlusion. We report on our own experiments on animals and on physiologicofunctional studies, which reveal the suitability of the smooth muscles as an ideal material for sphincter replacements. By histologic research it became obvious that autotransplantations of smooth muscles, carried out for the first time by the Department of Surgery of the University of Würzburg, are possible without significant tissue changes. The transplant is soon supplied by vessels which sprout ubiquitously and completely permeate it so that it can take over its function as sphincter. Meanwhile, the experience gained in experiments on animals has been transferred to surgery on humans. Incontinence and incontinence of the preternatural anus were eliminated in the first operations using autologous autotransplanted sphincteroplasties.

Animals↗

[Morphological findings on free intestinal muscle transplants as sphincter replacement].

Using autotransplants of an autonomous intestinal muscle segment a sphincter substitute and consequently a continent colostomy can be produced in humans and dogs. The histological study of the intestinal muscle section resected 1--28 weeks after implantation shows, in dogs, a good healing process and vascularization of the transplant muscle, which explains the clinical success. Even after many weeks only slight atrophy and fibrosis can be observed. Only a few of the intramural nerve plexuses perish. Some of the small intestine sphincters remain incontinent. The specimens show a more or less extensive hemorrhagic necrosis of the transplant with high inflammation. The reason for these complications is thought to be the mucosa glands, which were not completely removed from the vulnerable small intestine of the dog before the transplantation.

Animals↗

The regeneration of the cells of the macula densa after subtotal nephrectomy in the rat.

An autoradiographic study of the proliferative response of the cells of the Macula Densa days or months after the removal of 5/6 of the rat's kidney has shown that these cells are capable of division. The index of labelling of these cells is considerably lower than that of the other cells of the distal tubules. This applies of the kidney of normal controls and to the remnant after partial nephrectomy, shortly after operation as well as several months later. The cells of the Macula Densa therefore seem to represent a more stable population in the nephron. They therefore differ from the other cells of the distal tubules not only in appearance and function, but also in the pattern of cell proliferation.

Animals↗

The basement membrane of the atrophic kidney tubule. An electron microscopic study of changes in rats.

In a light and electron microscopic study of the rat's kidney after obstruction of the renal vein or after subtotal nephrectomy the tubular basement membrane changes occurring during the ensuing atrophy of the tubules have been examined. Characteristically, they consist of diffuse widening, focal thickening with vesicular and granular inclusions, circumscribed dissolution, or reduplication of this structure. These observations have led to the conclusion that the tubular basement membrane is formed by both interstitial and tubular cells, although the interstitial cells contribute the greater share to its formation, maintenance and renewal. The thickening of the basement membrane taking place in tubular atrophy must, however, be attributed entirely to the interstitial cells.

Animals↗

[The so-called chronic hyperplastic pharyngitis in childhood. A histological screening (author's transl)].

The clinical picture of chronic pharyngitis is well defined but insufficiently clarified as to its morphological nature. In our study of 12 children with chronic pharyngitis who underwent adeno-tonsillectomies small pieces of tissue of the posterior wall of the pharynx were microscopically examined. In most instances inflammatory infiltrations were absent. Present was a variably developed hyperplasia of the lymphatic tissues. In the more pronounced hyperplasias there was a lymphoepithelial disintegration that could account for the clinical manifestations and that perhaps could also be considered as a disposing factor for a bona fide pharyngitis. The micromorphological changes were divided into 4 stages.

Age Factors↗