Previous studies have proposed and supported a role for the proteolytic, irreversible conversion of xanthine dehydrogenase to xanthine oxidase (XO) in postischemic injury in a wide variety of organs. A second mechanism of conversion, due to sulfhydryl modification and reversible with dithiothreitol (DTT), is potentially important but has not been well investigated. In this study rat liver and kidney were found to produce significant amounts of DTT-reversible XO during normothermic global ischemia. Formation of reversible XO precedes that of irreversible XO by approximately 0.5 h with a strong correlation (r = 0.92) existing between the rate of irreversible XO formation and the concentration of reversible XO. The formation of reversible XO is preceded by a depletion of glutathione with concentrations of glutathione during ischemia correlating (r = 0.85) with the observed concentration of reversible XO. While a large increase in the extent of liver damage occurs concurrently with conversion in an in vivo liver model of liver ischemia, an ischemia-reperfusion regimen (1 h of ischemia plus 0.5 h of reperfusion) that resulted in no conversion caused significant elevations in serum glutamic pyruvic transaminase and serum glutamic-oxaloacetic transaminase. Rats depleted of XO by tungsten dieting release 65% less enzyme after the same insult, suggesting that endogenous XO may also participate in the damage process independent of any conversion.

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Chances of testicular salvage after torsion are higher if patients present early. The majority of patients presenting late (>6 h) require orchiectomy owing to testicular necrosis.

Esophageal epithelium generation, survivability of EEC on BMM-coated scaffolds, and engineering of unidirectional smooth muscle strands were successful in vitro. The hybrid approach of assembling individual tissue components in vitro using BMM-coated scaffolds and later amalgamating them to form composite tissue holds promises in the tissue engineering of complex organ systems.

From 1976 to 1995, 23 children, 4 boys and 19 girls, were treated at our department for sacrococcygeal teratomas (SCT). Their records were analyzed retrospectively, considering age at operation, histopathology, recurrences, and long-term evolution. One died on the 1st day of life following tumor rupture with hemorrhagic shock without surgical intervention. All others were operated upon at a mean age of 4.2 days for those 19 (= 82%) who were diagnosed in the neonatal period and whose histology proved benign. In the remaining 3 children, in whom tumor manifestation did not occur before 11 months, 13 months, and 10 years of age, respectively, histopathologic evaluation revealed 2 carcinomas and 1 yolk-sac tumor, and all 3 recurred. Overall, 5 patients died, the 1 mentioned above, 1 due to volvulus after laparotomy, and 1 from multiple associated congenital malformations. Two deaths were related to malignancy, whereby only 1 was a malignant teratoma diagnosed at the original operation. Eight children had recurrences, 2 were benign and 6 malignant, with 3 of the latter having been graded benign on histology of the primary tumor. Of the 18 surviving patients, 17 (93.5%) returned for clinical review following a standardized protocol. The average interval from the primary surgery was 12.3 years (range 3.5-22 years). Four had malignant tumors with a recurrence-free period of from 9 to 14 years; 5 (29.4%) had urinary or anorectal functional impairment. One child with a patulous anus presented with fecal soiling. Two reported nocturnal enuresis, 1 associated with perineal anesthesia. One had a neurogenic bladder with overflow voiding and bilateral third-degree vesicoureteral reflux. Second-degree reflux was found in the last patient. We conclude that follow-up after surgery for SCT should not only search for tumor recurrence but include the diagnosis and treatment of possible secondary urinary and/or fecal incontinence.