Neurological deficit following stereotactic radiosurgery for trigeminal neuralgia.

We report a unique case of neurological deficit from late onset multiple sclerosis (MS), in a 65-year-old woman, after stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN). At 3.5months post-SRS for TN, the patient developed ataxia and left leg paraesthesiae and brain MRI showed altered signal and enhancement in the vicinity of the right trigeminal root entry zone (REZ). The symptoms remitted following treatment with intravenous methylprednisolone, however, 10months post-SRS, the patient developed gait ataxia and left lower limb weakness. MRI showed persistent T2 changes at the REZ and multiple new non-enhancing white matter lesions in the cerebrum and spinal cord; and oligoclonal bands were present in the cerebrospinal fluid but not serum. A diagnosis of multiple sclerosis (MS) was made. This report raises the issue of whether the risk of radiation-induced toxicity is increased in patients with MS treated with SRS. We hypothesise that breakdown in the blood brain barrier secondary to the radiosurgery may have triggered a vigorous local inflammatory response.

Pathogenomics analysis of Leishmania spp.: flagellar gene families of putative virulence factors.

The trypanosomatid flagellar apparatus contains conventional and unique features, whose roles in infectivity are still enigmatic. Although the flagellum and the flagellar pocket are critical organelles responsible for all vesicular trafficking between the cytoplasm and cell surface, still very little is known about their roles in pathogenesis and how molecules get to and from the flagellar pocket. The ongoing analysis of the genome sequences and proteome profiles of Leishmania major and L infantum, Trypanosoma cruzi, T. brucei, and T. gambiensi ( www.genedb.org ), coupled with our own work on L. chagasi (as part of the Brazilian Northeast Genome Program- www.progene.ufpe.br ), prompted us to scrutinize flagellar genes and proteins of Leishmania spp. promastigotes that could be virulence factors in leishmaniasis. We have identified some overlooked parasite factors such as the MNUDC-1 (a protein involved in nuclear development and genomic fusion) and SQS (an enzyme of sterol biosynthesis), among the described flagellar gene families. A database concerning the results of this work, as well as of other studies of Leishmania and its organelles, is available at http://nugen.lcc.uece.br/LPGate . It will serve as a convenient bioinformatics resource on genomics and pathology of the etiological agents of leishmaniasis.

"Rhabdoid meningioma" lacking malignant features. Report of two cases.

We report 2 cases of meningiomas with rhabdoid morphology but lacking histological features of malignancy. Both occurred in adult women, one arising from the superior surface of the tentorium and the other in the Sylvian fissure. The tumors showed light microscopic, immunohistochemical and ultrastructural evidence of meningothelial differentiation together with diffuse or focal areas exhibiting rhabdoid morphology. The rhabdoid areas were characterized by cells with large cytoplasmic eosinophilic inclusions and large eccentric nuclei. Both cases showed areas with sheet-like growth and one had macronucleoli and brain invasion. The same case showed areas of necrosis that most likely related to pre-operative arterial embolization. Unlike most cases reported in the literature, these "rhabdoid meningiomas" lacked significant mitotic activity or other atypical features. The diagnostic and prognostic significance of this tumor entity is discussed along with a review of the literature.

Capacitance cytometry: measuring biological cells one by one.

Measuring the DNA content of eukaryotic cells is a fundamental task in biology and medicine. We have observed a linear relationship between the DNA content of eukaryotic cells and the change in capacitance that is evoked by the passage of individual cells across a 1-kHz electric field. This relationship is species-independent; consequently, we have developed a microfluidic technique-"capacitance cytometry"-that can be used to quantify the DNA content of single eukaryotic cells and to analyze the cell-cycle kinetics of populations of cells. Comparisons with standard flow cytometry demonstrate the sensitivity of this new technique.

"Ute surfing": a novel cause of severe head injury.

Riding on the load tray of a moving utility vehicle, often after drinking alcohol, is a recognized pastime among young Australian men. The cases presented here show that associated accidents can result in serious head injuries and probable permanent neurological deficits.