Biomedical subjects
Publications and source records attributed to W M Williams.
Wegener granulomatosis is a disorder of unknown etiology characterized by a necrotizing granulomatous vasculitis that primarily affects the paranasal sinuses, lungs, and kidneys. It is usually a disease of adults with infrequent cardiac involvement. We report the unusual presentation of this disorder in an adolescent with a cardiac mass. The findings on two-dimensional echocardiography and MR imaging are discussed.
Primary lymphoepithelioma-like carcinoma (LELC) of the lung is a neoplasm seen most commonly in the nasopharynx of individuals from south China and Taiwan, and is strongly associated with the Epstein-Barr virus. The case of a 62-year-old Chinese man with a rare primary lung T2N1M0 LELC of the left lower lobe is presented. The lesion was further notable because of the presence of necrotizing granulomatous inflammation. The patient was treated with surgical resection. After it was determined that the neoplasm was of primary lung origin, adjunctive chemotherapy was initiated. The role of adjunctive chemotherapy in this setting is discussed.
The elimination of the antiviral drug 5-ethyl-2'-deoxyuridine (EdUrd) by the isolated perfused rat liver was investigated. EdUrd (3.9-39 mumol) was injected into the perfusion reservoir and serial samples were collected for HPLC determination of EdUrd and its metabolites 5-ethyluracil (EUra) and 5-(1-hydroxyethyl)uracil (HEUra). At each dosage level, semilogarithmic plots of concentration vs. time showed apparent first order disappearance of EdUrd. However, with increasing dose, there was a progressive increase in EdUrd half-life from 18.9 to 36.4 min and decrease in total clearance from 5.5 to 2.5 ml/min, indicating dose-dependent elimination. Dose dependence was confirmed by the lack of superposition of logarithm concentration/dose vs. time plots obtained with different doses. After EdUrd administration, the concentration of EUra reached a peak value in about 1 hr, and then gradually decreased. The concentration of HEUra, which was initially much lower than that of EUra, increased throughout the experiment and appeared to approach a plateau at 2-3 hr. Biliary excretion of each ethylpyrimidine was negligible. 6-Benzyl-2-thiouracil, a thymidine phosphorylase inhibitor, slowed the disappearance of EdUrd and decreased the peak concentrations of EUra and HEUra. Cimetidine, a cytochrome P-450 inhibitor, had little effect on the rate of EdUrd disappearance, but caused a large increase in the peak EUra concentration and decrease in HeUra concentration. 3-Methylcholanthrene, a cytochrome P-450 inducer, increased the formation of HEUra but had little effect on the rate of EdUrd disappearance. The results indicate that the hepatic elimination of EdUrd is dose-dependent and involves an initial cleavage to EUra, which is then oxidized to HEUra.