Lymphoepithelioma-like carcinoma of the bladder is an uncommon neoplasm, of which 49 cases have been described in the English literature, none of which has been studied for p53 protein expression. We studied three muscle-infiltrating cases of this tumor using immunohistochemical, in situ hybridization and polymerase chain reaction (PCR) methods. The three cases were positive for epithelial markers and negative for lymphoid antigens in the tumoral syncytial areas. The intensive infiltrate of small cells was negative for epithelial and positive for lymphoid markers. This population was mainly made up of cytotoxic T-lymphocytes, positive for TIA-1. p53 protein was intensely positive in more than 90% of the epithelial component nuclei, being negative in the lymphoid cells. PCR study did not show mutations on p53. Both lymphocytes and epithelium were negative for Epstein-Barr virus markers, such as the latent membrane protein and EBER (Epstein-Barr-encoded RNA). The prognosis was very good after radiotherapy and chemotherapy treatment, preserving the bladder despite the muscle infiltration. The presence of an intense cytotoxic T-lymphocyte population may be related to this good prognosis. Both aspects, p53 protein status and T-lymphoid population, had never been studied before in bladder lymphoepithelioma-like carcinoma.

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Disturbances of bilirubin metabolism such as jaundice or pigment gallstone formation occur during total parenteral nutrition (TPN). We have studied the effects of TPN on bile flow and bile acid secretion and on the hepatobiliary transport of bilirubin in rats. Animals on parenteral nutrition for 5 days received 4.8 g of amino acids and 6.9 g of glucose daily. Controls were orally fed animals. Bile flow and bile acid secretion were not significantly modified by TPN. Serum bile acid and alkaline phosphatase levels were significantly increased in TPN animals when compared with the controls (+98% and +38%, respectively), which points to a relative cholestasis in the TPN rats. The biliary excretion of bilirubin monoconjugates and bilirubin diconjugates was significantly increased (+72% and +78%, respectively). This provides evidence for enhanced production of the pigment. Serum concentration of total bilirubin was enhanced in the TPN rats (+240%). The esterified/total bilirubin ratio in serum increased, whereas the bilirubin diconjugates/bilirubin monoconjugates ratio decreased. These facts, together with the minor reduction of hepatic bilirubin UDP glucuronosyltransferase activity (-12%), suggest that hyperbilirubinemia would be a consequence of both cholestasis and increased bilirubin production. The alterations reported here could contribute to the explanation of hyperbilirubinemia and pigment gallstone formation in patients maintained on parenteral nutrition.

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