Biomedical subjects
Publications and source records attributed to L Fiedler.
A 3-year-old child presented with vague abdominal pain, fever, leucocytosis and elevation of alkaline phosphatase. Ultrasonography revealed a space occupying process within the extrahepatic bile ducts surrounded by fluid. Various densities (between 15-25 Hounsfield units) were measured in this intrabiliary tumor by computed tomography.
This is a follow-up study of 171 patients concerning the patients' care and complications following biliary drainage. Complications caused by puncture and drainage are considered separately. External biliary drainage resulted in 39%, internal in 26% with complications. The influence of advantages and side effects upon the indications of biliary drainage is discussed. Prognosis concerning the survival rate depends on the underlying pathology: In obstructive jaundice caused by metastases the patients only survived two months while the mean survival rate in carcinoma of the biliary ducts is 18 months.
In 34 tumors of different origin 50 comparisons between the tumor response in the patients and in nude mice were performed. Combination chemotherapy was more successful than single agent chemotherapy. Out of the 25 combinations given, 9 (36%) effected a remission in comparison to 4 out of 25 (16%) after single agent chemotherapy. 13 patients got a remission which was found in 12 cases in the nude mouse, too. 37 patients did not respond to treatment and the same result was found in 36 cases in the nude mouse system. Xenografts gave a correct prediction for resistance in 97% and for tumor response in 92%. Despite great efforts to obtain a large number of comparisons, only 22 test results were available before the patients needed chemotherapy. In 13 cases chemotherapy was done simultaneously in the patient and in the nude mouse system. In 15 cases the patients were treated first. The xenograft system will not have practical significance in determining the treatment of the patients. Limitations are the duration of the testing, the testing rate of about 50% and the charges for nude mice. However, the highly correct prediction rates for tumor sensitivity and resistance validates human tumor xenografts as tumor models to test new drugs and combinations.
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PGE2, 13,14-dihydro-15-keto PGF2 alpha (DHK-PGF2 alpha) and PGF2 alpha were determined in arterial, central-venous and postgastric-venous plasma in a hemorrhagic shock model in mini pigs. PGE2 and DHK-PGF2 alpha significantly increased in all samples; highest values could be measured in postgastric-venous plasma, less in arterial, least in central-venous plasma. The ratio DHK-PGF2 alpha/PGF2 alpha was significantly increased during hemorrhagic shock in comparison with controls. A protective effect of certain E- and F-prostaglandins on gastric mucosa during hemorrhagic shock is assumed.
The perioperative behaviour of PGE2 and DHK-PGF2 alpha was studied in peripheral blood of patients undergoing lung surgery. The measurement of prostaglandins was performed by RIA after an extraction procedure. Common control criteria were observed. In 39 patients blood sampling was performed preoperatively and 2 weeks postoperatively. PGE2 and DHK-PGF2 alpha were significantly elevated in 8 patients with lung cancer before the operation. Postoperatively the concentrations decreased; 2 weeks later, DHK-PGF2 alpha was still slightly increased, PGE2 had normalized. 9 patients suffering from tuberculosis had normal serum concentrations of PGE2 and DHK-PGF2 alpha before and after resection procedures. In 8 cases the resection of benign lung diseases did not cause any abnormal reactions. In 2 special groups blood sampling was performed the following way: in 4 cancer patients and 3 tuberculosis patients blood was collected preoperatively, 5 times in the first hour after lung resection and 1 day and 2 weeks after operation. It could be demonstrated that PGE2 and DHK-PGF2 alpha almost completely normalized within the first postoperative hour in cancer patients, whereas no significant alterations could be found in tuberculosis. After discussion of technical problems in the measurement of prostaglandins the alterations of PG concentrations after lung cancer resection are emphasized.
Similarly good survival rates were obtained in 113 patients with kidneys transplanted from deceased persons as with patients on home dialysis. The retrospective study showed that fatal complications were not predominantly caused by septic diseases running fateful courses under immunosuppression, but by risk factors which were not recognized soon enough or were incorrectly treated. In our opinion, with careful preparation and supervision of these patients, even in the still unsatisfactory state of immunosuppressive therapy, the possibility exists of carrying out renal grafting without increased risk of mortality compared with dialysis treatment.
Gastrointestinal endoscopy with flexible glass fiber instruments is of increasing importance in surgery. Preoperative endoscopic examinations bring good progress in planning the operative procedure, especially concerning proximal selective vagotomy, pancreas surgery and reoperations on the large intestine. By applying postoperative endosocopic controls mucosal alterations can earlier be detected in the area concerned than by radiological methods; this has to be emphasized especially in view of patients operated upon for cancer. Emergency endoscopy in massive gastrointestinal bleeding is one of the outstanding tasks. Under certain circumstances risky abdominal operations can be avoided by therapeutic endoscopy.
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In a mechanical ileus model in 70 rabbits, the effects of PGF2alpha-infusions, PGE1- and PGA1-injections on jejunal pressure and serum gastrin levels were studied. PGF2alpha increases, whereas PGE1 inhibits jejunal motility. PGA1 produces no significant response. A modulation of neurotransmission is discussed. The serum gastrin levels can be decreased by PGE1-injections, whereas PGA1 effects only small decreases. The importance of the vagal mechanism for the release of gastrin is emphasized.
In 29 rabbits the action of PGF2 alpha and PGE2 was compared with prostigmine in a mechanical ileus model. PGE2 produces no therapeutical effect. PGF2 alpha delivered a significant increase of intraluminal intestinal pressure and of the amplitudes of peristalsis, lasting for about 5 minutes, whereas prostigmine made a long lasting significant enlargment of the amplitudes of peristalsis without any modification of intraluminal pressure. Serum gastrin levels increased after application of PGE2 and PGF2 alpha and remained constant after prostigmine. A possible way of action of PG's in the gastrointestinal tract is discussed, based on experiments concerning PG-application after different periods of time.
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