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Biomedical subjects

E Seifert

Publications and source records attributed to E Seifert.

At least 109 records · Page 6Linked to original sources
PubMed1984

Axon growth from limb motorneurons in the locust embryo: the effect of target limb removal on the pattern of axon branching in the periphery.

Metathoracic limb buds have been unilaterally ablated from locust embryos at 25 to 30% of embryonic development and the effect of this operation on the axon morphology of the motorneuron fast extensor tibiae (FETi) observed at later embryonic stages. In control embryos this neuron sends a single axon out the main leg nerve, nerve 5, to the extensor tibiae muscle in the femur. In limb ablated embryos the axon of FETi is found in a wide variety of aberrant peripheral nerve pathways and projects to a wide range of foreign muscles. There is a degree of apparent selectivity, but no rigid hierarchy, in the choice of pathway and muscle made by FETi. A high degree of variability is found between one embryo and another in the extent and pattern of axon branching. The axon of FETi is generally found in pathways that correspond to nerves in control embryos but on occasion grows along novel routes. An anteriorly directed dendritic branch, seldom seen in control FETi neurons, is frequently seen in experimental FETis. These findings are discussed in terms of the rules for specific axon growth in normal development.

Animals↗
PubMed1984

The influence of chronic subcutaneous nicotine administration on aldosterone and corticosterone plasma concentrations and the plasma renin activity.

Since adrenocortical hormones and the renin-angiotensin system are capable of inducing defined pathophysiologic changes in the cardiovascular system, similar to those observed after nicotine, experiments were performed in rats to investigate the effect of chronic nicotine administration on the plasma concentrations of aldosterone (PAC) and corticosterone (PCC) and on the plasma renin activity (PRA). The administration of nicotine (0.5 or 1.0 mg/kg s.c. twice daily) over a period of 8 weeks did not significantly affect PCC. However, PAC showed a marked decrease, which did not appear to be the result of a nicotine-induced ACTH inhibition, since a similar decrease in PAC was observed after suppression of ACTH by dexamethasone. PAC in rats with hereditary diabetes insipidus was depressed by nicotine to the same extent as in control rats. This argues against nicotine-induced stimulation of ADH leading to extracellular volume expansion, the cause of the observed decrease in PAC. Further experiments were carried out in which nicotine was administered chronically over 4 weeks (implanted osmotic minipumps infusing 0.17 mg/kg) in rats in which the endogenous activity of the renin-angiotensin system was modified by either a low- or high-salt diet. Nicotine did not influence PRA in the low-sodium group, whereas in the high-sodium group PRA increased after nicotine. The data show that chronic nicotine administration in rats does not activate salt- and volume-retaining endocrine systems. Plasma aldosterone even decreased, except in animals kept on a high-sodium diet, in which an increase of PRA under nicotine was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1983

[Malignant extrahepatic bile duct occlusion. Diagnosis and palliative treatment].

A diagnosis of malignant extrahepatic biliary obstruction was made in 123 cases by endoscopic retrograde cholangio-pancreaticography (ERCP) and (or) percutaneous transhepatic cholangiography (PTC). The diagnosis was confirmed by operation, biopsy or autopsy or further investigations and follow-up. The diagnosis was correct in 96% and false in only 4%. Clinical and biochemical findings were unreliable. Ultrasound investigations were accurate in 94% of cases with malignant obstruction low down. However, it was negative in cases with high obstruction in 19% due to the absence of dilatation of the intrahepatic biliary ducts. Consequently these cases could not be diagnosed without additional ERCP and PTC. ERCP and PTC also permit palliative treatment to be done. In 30% of all cases a palliative non-surgical treatment was performed such as endoscopic sphincterotomy with or without endoprosthesis or percutaneous transhepatic drainage.

Adult↗
PubMed1983

Palliative treatment of inoperable patients with carcinoma of the cardia region.

Endoscopic palliative treatment of inoperable patients with carcinoma of the cardia region is superior to surgical procedures that allow the feeding of patients. After dilating the malignant stenosis with an Eder-Puestow dilator, a Celestin or Atkinson tube is inserted endoscopically by means of the Nottingham introducer. In 25 of 26 patients the inserted tube functioned well until the death of the patient for an average of 109 days. Six patients are still alive and one patient has had the tube for almost 3 years. Of the 19 patients who died, 18 retained the tube until they died. The complication rate of the procedure was 11.5% with a 3.8% mortality related to tube insertion.

Adenocarcinoma↗
PubMed1983

Gastric polypectomy. Long-term results (survey of 23 centres in Germany).

In a survey of 23 endoscopy centres in the Federal Republic of Germany 6,182 cases are reported in which gastric polypectomies were performed. 1,177 patients were observed over a period of up to 7 years. Primary benign gastric polyps recurred in 6.1% most of them within 1 year after polypectomy, and genuinely recurrent polyps usually had a histological pattern identical to that of the ectomized polyps. In 32.5% new polyps occurred at different locations in the stomach, and most of them exhibited the same histological structure as the primary polyp. In 1.7% of primary benign solitary or multiple gastric polyps gastric carcinoma must be expected to develop. Follow-up examinations revealed only one carcinoma in 68 polyposis patients (= 1.5%), but in these cases, consideration must be given to a simultaneous carcinoma, which was observed in 8.5% at the first examination. In high-risk patients, endoscopic removal of protruded-type early gastric cancer and borderline lesion represents very satisfactory therapy. The recurrence rate of early gastric cancer was only 13.6% and of borderline lesion 9.7%. However, in cases of borderline lesions a cancer can be expected to develop in a further 8.6%. The consequences of this study are discussed.

Endoscopy↗
PubMed1983

[Treatment of duodenal ulcer with synthetic depot secretin - a double-blind study].

63 inpatients with duodenal ulcer disease were treated with either depot-secretin or placebo. Two different secretin-regimens were used. In group I 18 patients were given secretin twice daily. 11 ulcers from a total of 19 ulcers healed within 3 weeks. In group II 23 patients were given secretin once daily. 21 out of 28 ulcers healed within 3 weeks. In the placebo-treated group 24 ulcers were observed in 22 patients. Of these 15 healed within 3 weeks. There was no statistical difference in the healing rate between the 3 groups. However, depot-secretin significantly improved typical symptoms. Analgetics were used less frequently. Serious side effects did not occur.

Adult↗
PubMed1983

[Polypoid processes of the stomach].

Among epithelial gastric polyps the adenoma and the so called borderline lesion may be looked upon as precancerous lesions. The most common epithelial benign polyp of the stomach is the hyperplasiogenic polyp; cancerisation is rather rare and occurs only if epigenetic factors come into claim. Development of a carcinoma in a primary benign epithelial polyp is very rare (1,3%). In most cases of gastric polyposis the polyps consist of glandular cysts. Polyposis as such is not a pre-cancerous condition; not the number of polyps is decisive in this regard, but their histological structure. A typical, non-epithelial polyp of the stomach is the so called "inflammatory-fibromatous" polyp. Small, nonepithelial polyps should be removed by polypectomy; bigger polyps should be investigated microscopically after biopsies have been taken. Big non-epithelial polyps should be operated upon without previous histological investigation. Very small polyps, especially in the fornix region, and in old patients or patients in bad condition do not have to be investigated by endoscopy and biopsy.

Adenoma↗
PubMed1982

[Long term results after endoscopic sphincterotomy].

A multicenter study of 25 centers covering 9041 endoscopic sphincterotomies showed that choledochal concrements still represent the main indication (83,9%). Circumscript papillary stenosis (10.64%) and papillary tumour(2.06%) are the next most frequent indications. Complications after endoscopic sphincterotomy may be expected in 7.55% of cases, somewhat more frequent after papillary stenoses than after choledochal concrements. The most frequent complication is haemorrhage, followed by pancreatitis, cholangitis in cases of choledochal concrements, and perforation. Mortality is around 1.12%. Late results after endoscopic sphincterotomy a satisfactory and concrement-free bile ducts are seen in 91.62%. Freedom of complaints or improvements of symptoms occur in 93.4%. Recurrent stones occur in 5.77%, restenoses were seen in 3.14%. Late results after endoscopic sphincterotomy ar worse in papillary stenosis than in choledocholithiasis. Mortality figures are twice as high and danger of perforation seems to be more frequent. Endoscopic sphincterotomy is done increasingly as an emergency measure.

Ampulla of Vater↗
PubMed1981

Identified neurons in an insect embryo: the pattern of neurons innervating the metathoracic leg of the locust.

The population of motorneurons which send axons to the metathoracic leg of the locust embryo has been stained by a cobalt backfilling technique. Embryogenesis lasts 11 days and an adultlike distribution of motorneuron cell bodies is seen as early as day 6: Several identified adult motorneurons can be recognized in the embryo. The total number of filled cells, the overall distribution of stained cell bodies, and the relative positions of identified neuron cell bodies do not change between 6 days and hatching. No motorneurons are stained which are clearly not leg motorneurons, and an adult pattern of axon branching at the level of peripheral nerve roots is already present at day 6. These observations provide information about the timing of motorneuron production and motor axon growth into the embryonic limb. The development of central dendritic arborizations can also be followed. The results are discussed with respect to mechanisms for neuron determination and differentiation.

Age Factors↗
PubMed1981

[Early diagnosis of gastric cancer, a utopian idea? (author's transl)].

In order to improve the prognosis of gastric cancer it is necessary to discover the lesions at an early stage of the disease. Early gastric cancer has an excellent prognosis with a postoperative survival rate of 77 to 99%. Since 1970 we have diagnosed 76 cases of early gastric cancer and the percentage of early cancer out of all gastric cancers increased from 10 to 23%. This improvement is based on selected examinations of high-risk patients, on better diagnostic methods and on our better knowledge of macroscopic and histological appearance. In particular, the use of snare biopsy in protruding lesions and the implementation of continuous endoscopic-bioptic follow-up of all gastric ulcers until complete healing is achieved have improved the accuracy of histological verification. In 16 out of 76 cases of early gastric cancer a multicentric growth was observed. The diagnosis of gastric cancer at an early stage is not an utopian idea. It is reality when we pay attention to the aspects mentioned before.

Adenoma↗