Publications

The authors reviewed the records of 42 patients with HIV infection and status epilepticus (SE). Brain tumor and infection were the most common etiologies. The median duration of SE was 2.0 +/- 10 hours. Most patients (37 [88%]) responded to IV benzodiazepine or phenytoin treatment. Nevertheless, 12 (29%) patients died and 15 (36%) developed new neurologic deficits. In patients with HIV infection, aggressive management of seizures may limit the risk of SE.

Here, we investigate how Candida albicans, the most prevalent human fungal pathogen, protects itself from nitric oxide (*NO), an antimicrobial compound produced by the innate immune system. We show that exposure of C. albicans to *NO elicits a reproducible and specific transcriptional response as determined by genome-wide microarray analysis. Many genes are transiently induced or repressed by *NO, whereas a set of nine genes remain at elevated levels during *NO exposure. The most highly induced gene in this latter category is YHB1, a flavohemoglobin that detoxifies *NO in C. albicans and other microbes. We show that C. albicans strains deleted for YHB1 have two phenotypes in vitro; they are hypersensitive to *NO and they are hyperfilamentous. In a mouse model of disseminated candidiasis, a YHB1 deleted C. albicans strain shows moderately attenuated virulence, but the virulence defect is not suppressed by deletion of the host NOS2 gene. These results suggest that *NO production is not a prime determinant of virulence in the mouse tail vein model of candidiasis and that the attenuated virulence of a yhb1delta/yhb1delta strain is attributable to a defect other than its reduced ability to detoxify *NO.