Diagnosing progressive multifocal leukoencephalopathy: Positive predictive value of CSF JC virus quantitative PCR and importance of recognizing suggestive neuroimaging findings.

Objective: To determine the positive predictive value (PPV) of CSF John Cunningham virus (JCV) quantitative PCR (qPCR) for progressive multifocal leukoencephalopathy (PML), and highlight neuroimaging findings reported to be suggestive of this disease.

Methods: We reviewed patients at London Health Sciences Centre with a positive CSF JCV qPCR result. Patients were classified as true-positive if they had a clinico-radiographic presentation compatible with PML and no more likely alternative diagnosis.

Fused Heterocyclic Systems with an s-Triazine Ring. 34. Development of a Practical Approach for the Synthesis of 5-Aza-isoguanines.

Purine isosteres present excellent opportunities in drug design and development. Using isosteres of natural purines as scaffolds for the construction of new therapeutic agents has been a valid strategy of medicinal chemistry. Inspired by the similarity to isoguanine, we attempted to develop a practical method for the preparation of 5-aza-isoguanines.

Establishment of a counter-selectable markerless mutagenesis system in Veillonella atypica.

Using an alternative sigma factor ecf3 as target, we successfully established the first markerless mutagenesis system in the Veillonella genus. This system will be a valuable tool for mutagenesis of multiple genes for gene function analysis as well as for gene regulation studies in Veillonella.