Ambident reactivity of the nitrite ion revisited.
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Biomedical subjects
Publications and source records attributed to Stefan Roth.
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Impaired bone metabolism following urinary diversion through intestinal segments has always been a controversial subject of unclear clinical relevance. Whereas the perpetuated pathophysiological considerations seem conclusive in theory, the role of acidosis and malabsorption is less clear in animal experimentation and, even more so, in the clinical reality of modern continent diversion. In hardly any of the available contemporary case series was overt derangement of the acid-base balance, rickets or osteomalacia encountered. No consistent changes in osteotropic serum parameters could be found with normal calcium and phosphate in all patients. The assumption that colonic reservoirs have a higher risk of developing metabolic bone disease could not be confirmed by clinical data. As early correction of base excess is easy and probably a common policy in patients with intestinal urinary reservoirs, it will be virtually impossible to further study the natural history of bone metabolism after urinary diversion. While there is no need for a bone specific follow-up in asymptomatic adults with a normal acid-base balance, particular attention should be paid to children and to all patients with impaired renal function.
Testicular intraepithelial neoplasia (TIN) of the testis is the noninvasive precursor of testicular germ cell tumours (GCT) and can be detected by a single random biopsy in 5% of patients with GCT in the contralateral testes. Although it is generally presumed that TIN is dispersed throughout the testis, we realize in about 60% of TIN bearing tissue close to testis tumours that its distribution is not homogenously diffuse, but may be focal. Thus we tested whether we can improve diagnostic safety in detecting TIN by increasing the number of biopsies. We could finally evaluate 295 men with proven testicular tumours. Three biopsies of contralateral testes were taken (each 5 mm length) from one surgical incision site and fixed in Bouin's solution or glutaraldehyde. TIN cells were histologically identified by their typical morphological characteristics and additionally by placental alkaline phophatase (PlAP) immunohistochemistry. Patients revealed testicular tumour without contralateral TIN in 271 cases and with contralateral TIN in 24 cases (8.1%). In 6 of these 24 men with contralateral TIN the cells could be detected in only one (n=5) or two (n=1) of the three specimen investigated. That means in these six patients TIN could have been missed if only one single random biopsy was taken. By increasing the number of biopsies (=increasing the number of investigated seminiferous tubules) the detection rate of contralateral TIN may be increased up to 8.1%. Thus we recommend multiple testicular biopsies to increase the diagnostic safety in detection of TIN. Biopsies may be taken from one randomly chosen surgical incision site.