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Biomedical subjects

W Oehlert

Publications and source records attributed to W Oehlert.

At least 19 recordsLinked to original sources
PubMed1992

The effect of endotoxin on preirradiated mice.

Adult male mice were given a whole body irradiation with non-lethal doses of 2.5 or 5 Gy. Unirradiated animals served as controls. The animals (including controls) received a single injection of endotoxin (LPS from Salmonella abortus equi) with doses of 100, 200 or 400 micrograms one day up to one year after irradiation. Twelve, 24 or 48 hours after lipopolysaccharide (LPS) application the animals were killed and dissected. Animals which died spontaneously were also examined. Liver, lung, kidney, small intestine, and stomach were histologically investigated. The histological findings showed, that differences exist between irradiated and unirradiated mice and that the cause of death is also different for animals dying spontaneously. The investigations have shown that after irradiation phases of different degrees of sensitivity with regard to the endotoxin response exist. This behaviour can be observed by different lethality rates or in the light of the histological results. Moreover, the histological findings have shown, that distinct regenerative changes occur first of all in the liver, in the mucosa of small intestine, and the gastric mucosa, in which the number of differentiated cells compared with the mitotic active cells is reduced. It can be ascertained, that a whole body irradiation with 2.5 to 5 Gy enhances an additional injury by endotoxin weeks to months later. Contrary to this a preirradiation a few days before endotoxin application leads to a "protection" against the efficacy of endotoxin. These findings can be explained by modes of action described in literature, according to which endotoxins induce the formation of highly active mediators especially the tumor necrosis factor.

Animals↗
PubMed1991

A simple and rapid method for the detection of RNA in formalin-fixed, paraffin-embedded tissues by PCR amplification.

A simple and rapid method for the extraction, reverse transcription and PCR amplification of RNA from formalin-fixed, paraffin-embedded tissue is described. The procedure can be completed within 24 hours. In a first application of this method we detect human albumin mRNA in liver tissue, demonstrating the feasibility to retrospectively analyze gene expression and RNA viruses in fixed tissue.

Albumins↗
PubMed1990

An evaluation of gastric dysplasia in the years 1986 and 1987.

Since the fate and significance of gastric mucosal dysplasia is still largely unknown we have started a follow-up study for patients with dysplasia in the years 1986 and 1987. In this paper the short term results are reported. Dysplasia grade II was found in 2% of all patients and dysplasia grade III in 0.5%. The following results suggest a close-possibly sequential relationship of dysplasia and gastric cancer: dysplasia and gastric cancer are preferentially located in distal parts of the stomach; sex distribution of dysplasia and gastric cancer (especially intestinal type) are similar; considering the mean age of patients with dysplasia or gastric cancer we have observed that patients with dysplasia II were younger than patients with dysplasia III and both were younger than patients with gastric cancer of the intestinal type; during the short term follow-up (12-24 months) 4-8% of patients with dysplasia II and 18-20% of patients with dysplasia III showed a progression; of 26 carcinomas detected by follow-up of patients with dysplasia III 10 were early gastric cancer, 11 resectable with curative intent, 2 were metastatic and 3 without sufficient information for staging. We conclude therefore that gastric dysplasia is probably a true precancerous lesion that helps to identify high risk patients and thus contributes to the objective of an early diagnosis of gastric cancer.

Aged↗
PubMed1990

Prevalence of Campylobacter pylori as demonstrated by histology or CLO-test in different types of gastritis. A study in 5 clinically predefined groups of patients.

The prevalence of Campylobacter pylori infection as detected by histology was studied in 5 predefined groups of patients. The associated histologic and endoscopic findings were registered. Validity of CLO-test was tested against the histologic detection. The following groups of patients were studied: A) Non-ulcer dyspepsia (defined by one or all of three symptoms: heartburn, nausea/inappetence, halitosis/belching) B) control group (no specific symptoms, no ulcer, no history of gastric surgery) C) Duodenal ulcer D) Gastric ulcer E) Billroth I or II resection of the stomach. 200 patients were recruited for group A-C, in group D 134 patients and in group E 113 patients were studied. A mean prevalence of 60% was observed. Prevalence was highest in patients with duodenal ulcer (86%). In group D a prevalence of 65%, in A and E a prevalence of 54%, and in B of 40% were seen. The overall test sensitivity of the CLO-test compared against the histologic detection rate was 75%, the specificity 81%. Sensitivity was reduced in group A (69%) and E (53%) and in patients with inactive chronic gastritis (67%). In all groups patients with active forms of gastritis showed the highest prevalence of C. pylori infection. The specificity of the CLO-test was reduced in patients with duodenal ulcer (46%) and gastric ulcer (48%). Decreased specificity observed after therapy with histamin receptor (H2) blockers may explain this finding. The relationship of C. pylori infection with active types of gastritis or gastro-duodenal ulcer hints at a causal relation but is no definite proof of its etiologic role. The validity of the CLO-test seems questionable in patients with gastroduodenal ulcer or operated stomach.

Antacids↗
PubMed1990

Prolonged radioprotective activity of WR-2721 linked to dextran.

The radioprotective agent WR-2721 was linked to dextran and poly(glutamic acid) respectively, to obtain a prolonged radioprotective ability. Male mice were administered these water soluble polymer conjugates one to 72 hours prior to a whole body irradiation with X-rays. A prolongation of radioprotective efficiency was achieved with two dextran-(WR-2721)-conjugates. For a period of 24 hours between administration, and irradiation dose reduction factors of 1.14 +/- 0.04 and 1.10 +/- 0.03 respectively were found. After 72 hours, no protective effect was observed. Histopathological investigations of the liver for formation of tumors 200 to 600 days after irradiation seems to indicate that a protective effect is not produced by the dextran-(WR-2721)-conjugates.

Amifostine↗
PubMed1988

Light microscopic quantitative investigation on the effects of prostaglandin E2 (PGE2) on the lectin binding pattern in rat gastric mucosa injured by ethanol or sodium taurocholate.

We have used quantitative lectin histochemistry to study the cellular binding of peanut agglutinin (PNA) and soybean agglutinin (SBA) at the rat gastric corpus mucosa that has been injured experimentally by either ethanol or sodium-taurocholate and was protected by pretreatment of a cytoprotective dosage of the natural prostaglandin E2 (PGE2). The investigation was carried out in order to get access to possible differences in the amounts of intracellular secretory glycoproteins, associated with the prostaglandin-administration. The stomachs of rats injured by either ethanol or taurocholate revealed significantly reduced intramucosal amounts of glycoproteins with specific affinity for PNA and SBA, whereas in the stomachs of rats equally injured by the necrotizing agents, but pretreated by prostaglandin E2, the amounts of these glycoproteins remained close to the data observed in the control animals. These results give raise to two possible explanations: a) the decrease in the amounts of intramucosal glycoproteins might be due to a shedding of epithelial cells, the extent of which would then be less high in the prostaglandin treated stomachs. b) A second concept would imply influences on the glycoprotein metabolism, suggesting opposite traffics to be induced by the necrotizing agents than by the protective ones. Taken at their face value, our findings make it very likely that i) although prostaglandin-cytoprotectian did occur, this was not associated with a complete prevention from superficial cell loss at the rat gastric corpus mucosa and ii) the cytoprotective effect of prostaglandins might be mediated by influences on the intracellular glycoprotein metabolism, a process which could favour the defensive anti-ulcerogenic factors of the gastric mucosa.

Animals↗
PubMed1985

Drug-induced liver injury in liver biopsies of the years 1981 and 1983, their prevalence and type of presentation.

Based on the histological picture of liver biopsies examined in the years 1981 and 1983, drug-induced liver injury has been suspected in 131 and 170 cases. In relation to the total number of the examined liver biopsies this accounted for 6 and 9.6%, respectively. In only 20 (i.e. 15%), respectively 17 (i.e. 10%) of the cases, a drug-induced injury could be clinically excluded. However, a drug-induced injury was doubtlessly secured in 21 (16%) and 28 (16.5%) of the cases. The histological phenotype seen in association with the incriminated drug is presented. In 90 (68.7%) and 125 (73.5%) of the cases it was neither possible to secure nor to exclude the drug as cause of this damage, either because in 32/72 cases the clinical work-up was incomplete or because the drug-induced damage was clinically suspected, but not sufficiently documented by follow-up examinations after drug-withdrawal.

Adolescent↗
PubMed1985

The cytoprotective effect of prostaglandin E2 on taurocholate-induced erosions in gastric mucosa of the rat. Light microscopic, morphometric and scanning electron microscopic investigations.

The morphological changes associated with the cytoprotective effect of prostaglandin E2 (PGE2) following sodium-taurocholate (NaTC) erosive injury in the gastric mucosa were investigated in male rats. A single topic application of NaTC (80 mMol) induced multiple gastric erosions in all animals. Application of 200 micrograms PGE2/kg body weight prior to NaTC treatment led to a significant 90% decrease in the lesion-score in PGE2-protected animals. Light microscopic morphometric studies of the mucus-producing cells in the fundus mucosa were carried out. Within the PGE2-protected animals a significant increase was observed in the length of zones of the mucus-producing cells at the surface and in the foveolae (both PAS-positive and alcian-blue-positive cells). Compared to the NaTC-injured animals, this increase amounted to 8.1% for the PAS-positive, and 6.1% for the alcian-blue-positive zone. Compared to the untreated controls, these values were 4.7% and 3.2% respectively. In the scanning electron microscope we observed a characteristic explosive release of mucus and damage of the cell's surface membranes in the NaTC-treated animals. The PGE2-protected rats showed a predominance of exocytosis of mucus vesicles which formed a characteristic mucus network at the surface membrane. Our investigations suggest that the cytoprotective effect of PGE2 may, in part, be due to an increase in mucus production and to a modification of mucus adherence at the cell membrane.

Animals↗
PubMed1985

[Endoscopic and biopsy findings in the esophageal, gastric and duodenal mucosa before and after radiotherapy for Hodgkin's disease].

Esophago-gastro-duodenoscopies with multiple mucosa biopsies were performed before and after irradiation of the mantle field or the spleen pedicle in 13 patients with Hodgkin's disease in stage I and II. For the irradiation the photons of a 4 MeV linear accelerator were applied with focal doses of 40 to 44 Gy. Contrast simulator radiographs were made in order to verify the position within the irradiation field of the organs from which biopsies were taken. In 0/10 patients examined before the irradiation, 0/5 patients examined less than 15 weeks after the irradiation, and 0/12 patients examined 15 weeks or later after the irradiation, histomorphologic investigation of the mucosa of the esophagus showed no pathologic findings. With the same intervals of examination related to irradiation, the gastric mucosa showed a pathologic histomorphology in 1/13, 7/9, and 5/9 patients, respectively, and the duodenal mucosa in 0/13, 5/9, and 2/9 patients, respectively. With the exception of one ulcer in the duodenal bulb the histopathologic findings as well as the macroscopic findings were neither significant nor characteristic, i.e. not radiospecific. Most of these findings were inflammatory alterations of the mucosa, erosions, and capillarectasies.

Adult↗
PubMed1984

[Diagnostic value of unselected biopsies during gastroscopy].

In a prospective study 1414 unselected biopsies were obtained during 509 consecutive gastroscopies. Concordance between endoscopic and histological diagnosis was judged by means of the kappa coefficient. Best agreement was obtained with biopsies from the duodenal bulb, at 67.6% (kappa = 0.39). With biopsies from the body of the stomach agreement was only 35.7% (kappa = 0.12), from the antrum 28.8% (kappa = 0.10). Degree of agreement between endoscopic and histological result was independent of the instrument used, but was clearly dependent on the examining doctor and the number of examinations. The results suggest that clinically significant disease is often overlooked during endoscopy alone, unless simultaneously obtained unselected biopsies are examined at the same time. Thus, endoscopic examination alone missed Crohn's disease, chronic atrophic gastritis and various degrees of dysplasias. Unselected biopsy aids in objectifying the gastroscopic findings and in securing the diagnosis of various diffuse gastric mucosal changes.

Biopsy↗
PubMed1980

Electron microscopic studies on the small intestinal mucosa of rats after mechanical intestinal obstruction and ischemia.

Ultrastructural changes in the small intestine during the early phase following mechanical obstruction were compared with those after vascular ligation. In both experiments (the early phase of mechanical ileus and ischemia) intestinal epithelial cells at the tips of villi showed common features. One of the most significant changes was an alteration in microvilli, with fragmentation into vesicles, narrowing of apical microvilli and decrease in number. The other change was fatty degeneration of the epithelial cells, which was accompanied by vesiculation of smooth endoplasmic reticulum beneath the terminal webs, fat deposition and dilated Golgi complex containing fat. These observations suggest that in the early phase of mechanical ileus, ischemic damage plays an important role.

Animals↗
PubMed1979

Electron microscopic studies on the small intestine of rats after mechanical intestinal obstruction.

The morphologic changes of the small intestine after the mechanical obstruction were studied by light and electron microscopy. After the ligation of the upper small intestine, segments of jejunum, both proximal and distal to the site of obstruction, were removed at intervals varying from 45 min to 24 h. The essential changes were found in the epithelial cells of the tips of villi, and few morphologic differences were recognized between samples proximal and distal to the site of obstruction. The most remarkable changes in the mucosa were the pseudopodlike extension of the cytoplasm, vacuolar alteration of the villus epithelial cells, desquamation of these degenerated cells, and the dilatation of the epithelial intercellular spaces. A few epithelial cells showed hypertrophy of the smooth endoplasmic reticulum. In the submucosa, vascular stasis and edema were observed throughout the course. The mechanism of fluid loss into the intestinal lumen was discussed briefly.

Animals↗