Biomedical subjects
Publications and source records attributed to G Staehler.
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As an adjunct to the monitoring of intracellular high-energy phosphorus metabolites by 31P NMR1 for assessment of renal viability, a study of vasculature of preserved kidneys was performed by Image-Guided Volume Selective 19F MR Spectroscopy. 1H and 19F of the same preserved rat and porcine kidneys were obtained. The technique enabled the analysis of the vessel and tissue properties and opens new possibilities for pretransplant assessment of renal vasculature.
The increased risk of colon carcinoma following urinary diversions via colon makes knowledge about preneoplastic changes necessary. In 30 ureterosigmoidostomy patients with a mean observation period of 16 years flexible sigmoidoscopy with biopsies and nitrosamine analysis of the feces/urine mixture have been performed. In the biopsies we found an increased sialomucin concentration at the ureterocolonic anastomosis in 29.2%--sialomucin is supposed to be a preneoplastic change--with no significant difference to the mucosa periureteral and in the rectum. In 58.3% we found chronic inflammation at the anastomosis, in 29.2% periureteral and 4.2% in the rectum. 2/30 patients developed adenocarcinoma, 1 patient an atypia and 1 patient a juvenile polyp. The nitrosamine excretion of the ureterosigmoidostomy patients were significantly increased compared to 20 healthy controls with no correlation to the histology at the anastomosis or the observation time. Because of the multilocular presence--colon carcinomas develop only at the anastomosis--sialomucin and chronic inflammation seem to be no preneoplastic changes in urinary diversions. The nitrosamine analysis is not suitable for routine follow-up as well.
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Tumor cells of three urological longterm cell lines have been labelled with 35[S]-Methionin and added to red cell concentrates. Red cell concentrates rich in tumor cells were passed through a cell saver and two special membranfilters under standard conditions. The 35[S]-Methionin labelled tumor cells were detected by liquid scintillation counting. On an average, only 0.027% of the radioactivity was left after passing through the cell saver and the membran filters in the 12 experiments. If investigations in clinical use of cell-saver and membran filter confirm these results, there will be significant consequences in urological tumor surgery by the possibility of transfusing the salvaged autologous blood.
Twenty rats were randomized into a vesicosigmoidostomy and an unoperated control group. In both groups the 24 hour excretion of secondary amines, nitrate, nitrite and nitrosamines was measured before and after gavage of proline and nitrate, piperazine and nitrate, N-nitrosoproline, mono-N-nitrosopiperazine. The urinary nitrosamine concentrations were not significantly different between both groups neither before nor after application of the several substances. Thirty rats were randomized into two vesicosigmoidostomy groups with and without antibiotic coverage and an unoperated control group. After ligation of distal rectum and mesosigmoid the rectosigmoids were removed. No significant concentrations of volatile nitrosamines could be measured in the rectosigmoid contents of the three groups. One hundred and twenty rats randomized into three groups following vesicosigmoidostomy received the potential nitrosamine antidotes sodium-2-mercaptoethane sulfonate or sodiumpentosan-polysulfate or acted as controls. 12/118 (10.2%) developed adenomas and 25/118 (21.2%) adenocarcinomas at the vesico-colonic anastomosis with no significant differences between the three groups concerning tumor incidence or mortality. The results show that colon carcinomas occur in a rat model for ureterosigmoidostomy without evidence for thus induced nitrosamine formation. This and the missing effect of nitrosamine antidotes suggest that other factors than nitrosation must be responsible for colon carcinogenesis following urinary diversion via intestine.
The bacterially catalyzed formation of nitrosamines in the rectosigmoid is a favorite theroy for the increased risk of colon carcinomas following ureterosigmoidostomy. The urine/feces mixtures of 20 ureterosigmoidostomy patients were analyzed for nitrate, nitrite, volatile and nonvolatile nitrosamines prior to, and after, oral administration of vitamin C, a known nitrosation inhibitor. Following a 4-week period of daily ingestion of 2 g vitamin C (1 g in children) there was a slight, but not significant, decrease of volatile and nonvolatile nitrosamines and nitrite, as well as a nonsignificant increase in nitrate in the urine/feces of these patients. No correlation between the vitamin C concentration in serum or urine/feces mixture and the nitrosamine excretion was observed. These results suggest that the administration of vitamin C is not a suitable method for prophylaxis of endogenous nitrosation in ureterosigmoidostomy patients. Clinical and experimental findings implicate that factors other than nitrosamines play an important role in colon carcinogenesis of patients with ureterosigmoidostomies or other forms of urinary diversions using the small or large bowel.
The therapeutic management of carcinoma of the prostate and the bladder depends on the tumor involvement of the hypogastric and obturatoric lymph nodes. Pelvic lymphadenectomy reveals the most accurate information about metastatic spread to the lymph nodes in patients with prostatic carcinoma. The pathologic information it offers cannot be acquired by any other diagnostic procedure. In cadaver studies and animal experiments in dogs we developed a technique for laparoscopic pelvic lymphadenectomy. Since 1990 six patients underwent a transperitoneal laparoscopic lymphadenectomy. First results show the feasibility of our operative technique. Currently the future role of laparoscopic pelvic lymphadenectomy in clinical management of prostatic carcinoma cannot be estimated.
Definite suspensions of malignant cells from three human tumor cells lines (bladder, prostate and renal cell carcinom) were passed through a cell saver (Althin Mediplast) and a leucozyte removal filter (PALL RC 100) under standard conditions. The examination of the solutions did not detect any malignant cells at all. If investigations with malignant cells in the blood will confirm these results, the use of intraoperative autotransfusion in urological tumor surgery would be possible.
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In a prospective randomized trial intravesical prophylaxis for recurrence of superficial bladder cancer with BCG versus KLH was performed in 42 patients, 38 of whom were then evaluable. After a mean observation period of 20 +/- 7 months (8-32 months) 41.2% (7/17) of the patients in the KLH and 14.3% (3/21) of the patients in the BCG group developed recurrent bladder tumours. The recurrence rate according to EORTC was 1.95 in the KLH group versus 0.76 in the BCG group. Among the BCG treated patients, 60% (15/25) had cystitis and 28% (7/25) fever, whereas only 1 of 19 (5.3%) patients treated with KLH had cystitis. BCG is a highly effective prophylactic against recurrence of superficial bladder cancer. Intravesical instillation therapy with KLH has only a slight prophylactic effect if treatment is started 6 weeks postoperatively.
Urinary diversion in both a rat model for ureterosigmoidostomy and in ureterosigmoidostomy patients result in an increased incidence of colon tumours. Bacterial and chemical investigations on feces-urine mixtures from both the rat model and ureterosigmoidostomy patients showed the presence of a complex nitrate-reducing bacterial flora in both rats and humans. This bacterial flora actively reduced urinary nitrate to nitrite in humans and increased the endogenous formation of N-nitroso compounds. No evidence of urinary nitrate reduction and increased nitrosamine formation in the rectosigmoid of rats was found. The results support the N-nitrosamine theory of carcinogenesis of the colon following ureterosigmoidostomy in humans, but not in rats. As the rat model induces colon carcinomas, factors other than the increased endogenous formation of N-nitroso compounds in the rectosigmoid may contribute to the initiation of colon carcinomas following ureterosigmoidostomy.
We followed postoperatively 75 patients who underwent ureterosigmoidostomy between 1942 and 1987. Of the patients 30 were asked to undergo routine examination, including fiberoptic sigmoidoscopy with biopsy and analysis of a urine-feces slurry for nitrate, nitrite and nitrosamines in comparison to 20 control volunteers. After a mean observation of 14 years 7 months (1 to 46 years) 64.5% of the patients had bilaterally normal kidneys without any previous complications, 77.5% of the renal units being normal. Sigmoidoscopic biopsy revealed 3 carcinomas at the ureterocolonic junction resulting in an 8.5 to 10.5-fold increased risk of colon carcinoma compared to the general population. The excretion of nitrite and N-nitrosamines was increased, and nitrate excretion was decreased compared to healthy control volunteers, suggesting endogenous formation of nitrosamines by bacterially reduced nitrate and endogenous amines. The urological long-term results of ureterosigmoidostomy are similar to those of conduits. However, the increased incidence of colon carcinoma is not yet proved to be higher than in conduits.
We report on a 42-year-old patient with a Wilms tumour (nephroblastoma) of the right kidney, which was detected incidentally by sonography. Both radiological examination and intraoperative examination of a quick-frozen section led to a diagnosis of malignant renal tumour. Post-operative histological examination showed a nephroblastoma of predominantly epithelial cell type with no signs of anaplasia. Only about 210 cases of Wilms tumours in adults have been reported in the world literature so far. Because of this low incidence and the frequent lack of any clear distinction from sarcomatoid renal cell carcinoma in terminology and histology, no standardized therapy regimens exist. The prognosis with a 3-year survival rate of 24%-44% is poor compared with that of Wilms tumours in children. In a literature review the current status of knowledge about nephroblastomas in adults is discussed.
31 patients with advanced renal cell carcinoma underwent abdominal MRI which were examined by an independent experienced radiologist and compared with the intraoperative findings. 12 of 13 vena caval tumor thrombi were diagnosed correctly, 1 small tumor thrombus in a case with large retroperitoneal lymph nodes compressing the vena cava could not be detected. The extension of the tumor in the vena cava could exactly be described in topographic relation to liver, diaphragm and right atrium which is important for planning the operative procedure.
Fifteen patients in whom superficial bladder tumours (TIS GII-III) recurred after the unsuccessful application of other treatments were treated by photodynamic therapy (PDT) and observed for 24-54 months. The results of therapy were evaluated by regular three-monthly check-ups (endoscopy, cytology, bladder mapping, renal ultrasonography) as well as by computed tomography (CT) examination at 8- to 13-month intervals. In nine patients treated by PDT no tumour recurrence has been found over the whole observation period. Two patients have remained free of tumour (12 and 14 months) after repeated transurethral resection (TUR) and Nd-YAG laser therapy after PDT. Two patients required a second application of PDT before the treatment goal was achieved. In one of these cases a circumscribed dysplasia which appeared at the left ostium 26 months after PDT was treated by TUR and Nd-YAG laser. Further observations showed it had been successfully removed. In six patients slight mucosal atypia persisted for at least 2.5 years. In the short-term course of further cases (n = 12) one cystectomy has to be performed because of bladder shrinkage. According to these preliminary results, PDT (with strict patient selection--worst-case situation with recommended cystectomy) is justified for recurrent superficial TIS bladder carcinoma.
Following the development of suitable equipment for the endoscopic application of an Nd-YAG laser in this department, the laser has been used routinely in the management of bladder cancer since 1978. To evaluate side effects and efficiency, 252 consecutive laser treatments were evaluated with a minimum follow-up of 12 months. Side effects were few (0.3% perforation) and patients tolerated the treatment very well. The general recurrence rate of T1 tumours varied from 33% for primary carcinomas to 54% for recurrent tumours, but the incidence of local recurrence was only 7%. The long-term results of laser treatment showed a decrease in the local recurrence rate when compared with the results of conservative electocautery resection, but there was no significant influence on the total recurrence rate.