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Biomedical subjects

K Dahm

Publications and source records attributed to K Dahm.

At least 19 recordsLinked to original sources
PubMed1978

[Biosynthesis of C19- and C21-steroids in tissue slices of paraganglioma and pheochromocytoma (author's transl)].

The biogenesis of C19- and C21-steroids has been studied in tissue slices of a paraganglioma, of a pheochromocytoma and of human adrenal cortex using radioactive steroids. Slices of paraganglioma as well as of pheochromocytoma metabolise 17-hydroxyprogesterone to cortisone, cortisol, 11-deoxycortisol and testosterone. The rate of formation of these steroids, however, by the two tumours is 8--15 times less than that in normal adrenal cortex tissue. After incubation of dehydroepiandrosterone with tissue slices of paraganglioma and pheochromocytoma, 7alpha-hydroxydehydroepiandrosterone, 11beta-hydroxy-4-androstene-3,17-dione and 4-androstene-3,17-dione were found as metabolites; testosterone was converted by both tissues to 4-androstene-3,17-dione. 17-Hydroxypregnenolone was converted to a small extent (1.7%) to dehydroepiandrosterone by slices of paranganglioma. These results show that enzymes of steroid biosynthesis (hydroxylases, oxidoreductases, delta4(-5)-isomerases, C17(-20)-desmolases) are present in both paraganglioma and pheochromocytoma.

Adrenal Cortex↗
PubMed1978

[The diagnosis of annular pancreas (author's transl)].

Annular pancreas is a rare congenital malformation of the gut; frequently it becomes manifest in adult life. The clinical picture and radiological appearances are dominated by stenosis of the duodenum. The only method for diagnosing annular pancreas up to the present was the barium meal. Its diagnostic accuracy, however, is limited. A knowledge of the characteristic radiological appearances is helpful unless other abnormalities confuse the interpretation. E.R.C.P. is an important advance in diagnosis. The diagnosis of annular pancreas can be made by demonstrating an accessory duct system. The literature is reviewed.

Adult↗
PubMed1978

[Anti-reflux plasty for oesophageal varices (author's transl)].

An operation to prevent reflux was carried out in 36 patients with oesophageal varices; its aim was to prevent ulceration of the oesophageal mucosa due to gastric or duodenal secretions. The anti-reflux plasty consists of a distal gastrectomy with orthograde, isoperistaltic interposition of 20 cm. of jejunum between the gastric remnant and the duodenum, and fixation of the fundus and fornix. During the first three months, and even somewhat later, there was a little passage of contrast from the interposed jejunum into the stomach and duodenum. The reflux from the duodenum was, however, very small and only reached the vicinity of the stoma so that a duodeno-gastric reflux could be practically excluded. The fundus-fornix fixation resulted in absence of radiologically demonstrable gastro-oesophageal reflux. The interposed jejunal loop took over in part the function of the stomach, regulated gastric emptying and acted as a valve during upper gastro-intestinal transport.

Duodenum↗
PubMed1978

[Peritoneo-venous ascite drainage using the Le Veen shunt].

Ascites drainage by using the Le Veen shunt should be attempted after other treatments have failed. A silicon catheter connects the intraperitoneal space with the vena cava superior via a jugular vein. According to our own observations, misleading may occur during the insertion of the venous part of the catheter into the vena jugularis externa. Later, a thrombosis may occur. Intra- or postoperative roentgen controls for corrections or replacements seem advisable.

Ascites↗
PubMed1978

[Annular pancreas (author's transl].

Eight cases of annular pancreas treated at the University Hospital of Hamburg between 1964 to 1977 are presented. In adults, the disease follows the pattern of chronic duodenal obstruction being often asymptomatic unless complications such as peptic ulceration, acute pancreatitis or bile duct obstruction occur. Preoperative diagnosis is only possible by using endoscopic retrograde pancreatography. Attention is drawn to the frequent co-existence of other malformations of the gastro-intestinal tract. Treatment should consist of relief of any obstruction to the duodenum by a bypass gastrojejunostomy is recommeded in those cases having associated peptic ulcer. The division or resection of the annulus bears the risk of fistula formation. A brief review of the theories of the development of annular pancreas is given.

Adult↗
PubMed1977

[Cancer risk of the stomach resected for ulcer. The role of duodenogastric reflux (author's transl)].

The purpose of this study was to find whether the reflux of bile and pancreatic juices following stomach resection (duodenogastric reflux) enhances the incidence of carcinomas near the gastroenteric anastomosis. 72 male Wistar rats were subjected to stomach resection. The gastroenteric anastomosis (GE) was performed either as short loop anastomosis (Billroth II; n = 39), thus providing a continuous duodenogastric reflux, or as Y-shaped GE (according to Roux; n = 33). By the latter technique, bile and pancreatic juices are derived quantitatively into the jejunum without coming into contact with the remaining part of the stomach. During a period of 33 weeks, operated rats as well as intact animals were given the carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (NG; 120 mg/l) in the drinking water. At autopsy, 33 to 36 weeks after daily oral administration of NG, most of the tumours were found in operated rats undergoing continuous reflux (Billroth II group). In contrast to these findings, the incidence or carcinomas was significantly lower in animals without reflex (Roux group or intact control rats).-The results of our experiments demonstrate that, in rats, the duodenogastric reflux contributes substantially to the development of carcinomas of the resected stomach.

Adenocarcinoma↗
PubMed1977

Experimental carcinogenesis in the resected colon of the rat.

Until now, carcinoma of the large intestine resected previously for benign disease has not been published. However an increasing number of patients resected for Crohn's disease, diverticulitis or trauma may reach nowadays a high lifespan. On the other hand, it is known that the gastroenteral anastomosis is predisposed to cancer development. In this study, the question of whether the large intestine following colotomy or ileotransversostomy is sensitive to carcinogenesis is examined. Male Wistar rats, subjected to colotomy or resection and ileotransversostomy, were treated weekly by subcutaneous injection of 1,2-dimethylhydrazine (12 mg/kg body weight) for seven weeks. The animals were killed 54 weeks after the first injection. At autopsy, 21 out of 29 operated rats had developed adenocarcinomas of the remaining colon. Intact control animals had the same incidence of malignant degeneration of the large bowel. When the anastomosis is chronically irritated by inflammation or by formation of a diverticulum, development, of carcinoma near the stoma was observed. This was the case in three rats of 28 animals. The results demonstrate that the resected colon of the rat is not more sensitive to experimental carcinogenesis than the intact one.

Adenocarcinoma↗
PubMed1977

[Malignant degeneration of experimental ulcerative colitis of the rat following s.c. injection of 1,2-dimethylhydrazine (author's transl)].

Animal experiments were performed to answer the question whether ulcerative colitis is predisposed to malignant degeneration. Male Wistar rats were given aqueous solutions of degraded Carrageenan (4%; w/v). After induction of ulcerative colitis, 1,2-Dimethylhydrazine (DMH; 132 mg/kg body weight) was applicated during a period of 7 weeks. 17 of 18 rats developed multiple adenocarcinomas in the distal colon 15 weeks after the last injection of DMH. The Carrageenan induced colitis was localized predominantly in the distal part of the large bowel. Only 3 rats of a control group of 18 animals exposed to DMH only showed carcinomas of the colon. The difference is proven significant (P less than 0.01). Carrageenan for itself caused no malignancy. The results of the experiments demonstrate that, during ulcerative colitis, the colon of the rat is more susceptible to induction of cancer than the intact one.

Adenocarcinoma↗
PubMed1977

[Peptic anastomotic ulcer induced by continuous duodenogastrix reflux (author's transl)].

Different types of duodenal by-pass operations with and without duodenogastric reflux were performed on 54 male Wistar rats. The results of our investigation show that following duodenal by-pass with reflux peptic anastomotic ulcer regularly occurs. The constant reflux of bile and pancreas juice is the most important aetiologic factor in the development of ulcer in the vicinity of the anastomosis between the stomach and small intestine. Stasis in the by-passed duodenum (afferent loop syndrome) promotes ulcerogenic action of reflux. In the absence of the pylorus the effects of reflux ans stasis potentiate, resulting in a high frequency of ulcer (greater than 90%). With intact pylorus the incidence is low. Duodenogastric reflux prevents hydrochloric acid secretion significantly (P less than 0.01); hydrochloric acid thus plays a minor role in the development of experimental anastomotic ulcer of the rat. -In considering the prophylaxis against anastomotic ulcer, there findings support the claim of avoiding surgical techniques involving duodenal by-pass and reflux (Billroth II with short loop GE). Gastric resection should, therefore, aim at the reconstruction of the orthograde peristalsis.

Animals↗
PubMed1977

[Duodenogastric reflux and anastomosis abscess. Experimental study].

Different types of duodenal by-pass operations with and without duodenogastric reflux were performed on 54 male Wistar rats. The results of our investigation show that following duodenal by-pass with reflux peptic anastomotic ulcer regularly occurs. The constant reflux of bile and pancreas juice is the most important aetiologic factor in the development of ulcer in the vicinity of the anastomosis between the stomach and small intestine. Stasis in the by-passed duodenum (afferent loop syndrome) promotes ulcerogenic action of reflux. In the absence of the pylorus the effects of reflux and stasis potentiate, resulting in a high frequency of ulcer (greater than 90%). With intact pylorus the incidence is low. Duodenogastric reflux prevents hydrochloric acid secretion significantly (p less than o,o1); hydrochloric acid thus plays a minor role in the development of experimental anastomotic ulcer of the rat. -- In considering the prophylaxis against anastomotic ulcer, these findings support the claim of avoiding surgical techniques involving duodenal by-pass and reflux (Billroth II with short loop GE). Gastric resection should, therefore, aim at the reconstruction of the orthograde peristalsis.

Abscess↗
PubMed1977

[Antireflux plasty. A new path in the management of bleeding esophageal varices].

Early results with a new operative method for the prevention of recurrent hemorrhage of esophageal varices are reported. The principle of this method is the protection of the esophaguscardia region against the corrosion of biliary reflux. The pathogenesis is based on clinical, endoscopic, and experimental findings. The term "Antirefluxplastik" (antirefluxplasty) is chosen for this type of operation. A segment of about 20 cm of the upper jejunum is excluded and retrocolically interposed between the resected stomach and the duodenum. The procedure is completed by a hemifundoplication and a proximal vagotomy. There were 25 patients treated because of recurrent bleeding of esophageal varices. A follow-up was done on 10 patients from 8 to 12 months postoperatively. Lower frequency of hemorrhage in comparison with the preoperative period is demonstrated. Bleeding recurred in only one patient. Endoscopically gastric erosions were proven the source of hemorrhage. These positive intermediate results encourage us to present the "Antirefluxplastik" as an alternative to conventional operations in the surgery of portal hypertension.

Esophageal and Gastric Varices↗
PubMed1976

[Experimental study on the pathogenesis of anastomotic ulcers (author's transl)].

Various forms of operative duodenal exclusion with or without duodenogastric reflux were performed on 54 male Wistar rats. It was demonstrated that after duodenal exclusion with reflux peptic ulcers regularly occur at the site of anastomosis. Continuous reflux of bile and pancreatic secretion is the decisive factor in the development of ulcer at the anastomotic border between stomach and jejunum. Stasis in the excluded duodenum (syndrome of the afferent loop) promotes the ulcerogenic reflux effect. If there is no pylorus, reflux and stasis are potentiated to the highest incidence of ulcer (more than 90%). These results indicate that operations with duodenal exclusion and reflux (Billroth II) should be discontinued.

Animals↗