Search

Pentamidine isethionate induced torsades de pointes in a 33-year-old woman with acute myelogenous leukemia. This is the first report of Pentamidine-induced torsades de pointes in Japan for over ten years. On the 4th day of intravenous pentamidine for Pneumocystis carinii pneumonia, asymptomatic sinus bradycardia was noted with QT interval prolongation, and torsades de pointes were revealed on the 8th day. Although torsades de pointes was dissolved with discontinuation of the intravenous pentamidine and administration of magnesium sulfate, sinus bradycardia and prolonged QT interval persisted. Ventricular pacing resulted in no arrhythmia and normalization of the QT interval on the 10th day after discontinuation of pentamidine. Careful monitoring of the electrocardiogram should be carried out during intravenous pentamidine therapy.

We have previously shown that ethanol administration results in tyrosine phosphorylation of the 130 kDa protein in rat brain, and identified the protein as Cas, the crk-associated src substrate. In the present study, we demonstrate that Cbl of a 120 kDa protein is also tyrosine-phosphorylated in the cerebellum in response to ethanol administration. We also investigated whether Fyn kinase was involved in ethanol-induced Cbl phosphorylation. Immunoprecipitation experiments showed that the amount of coimmunoprecipitated Fyn kinase with an anti-Cbl antibody increased in extracts from ethanol-administered rats compared to those from saline-administered rats. Exogenous Fyn kinase was shown to phosphorylate on tyrosine residue(s) of Cbl from the cerebellum in vitro. Furthermore, Fyn kinase and Cbl were demonstrated immunohistochemically to be coexpressed in white matter in the cerebellum. These findings indicate that Cbl is tyrosine-phosphorylated in rat cerebellum in response to ethanol administration, and also raise the possibility that Fyn kinase may be involved in the process.