Acute Presentation of Vestibular Schwannoma Secondary to Intratumoral Hemorrhage: A Case Report and Literature Review.

Background: Vestibular schwannomas (VS) are common slow-growing tumors that typically present with the insidious progression of unilateral hearing loss, tinnitus, vertigo, and gait imbalance. Clinically significant intratumoral acute hemorrhage is exceedingly rare and can present with the acute onset of symptoms, neurologic deterioration, and significant dysfunction of cranial nerves VII and VIII. We discuss a 40-year-old man who developed mild hearing loss and headaches over the course of a month before presenting with a large acutely hemorrhagic vestibular schwannoma.

Coherent stochastic oscillations enhance signal detection in spiking neurons.

We study the effect of noisy oscillatory input on the signal discrimination by spontaneously firing neurons. Using analytically tractable model, we contrast signal detection in two situations: (i) when the neuron is driven by coherent oscillations and (ii) when the coherence of oscillations is destroyed. Analytical calculations revealed a region in the parameter space of the model where oscillations act to reduce the variability of neuronal firing and to enhance the discriminability of weak signals.

In vitro activity of cycloSal-nucleoside monophosphates and polyhydroxycarboxylates against orthopoxviruses.

Because variola virus might be used as a pathogen in biological attacks, there is an urgent need to provide effective antiviral drugs for the treatment of orthopoxvirus infections. Thus, the aim of the present study was to test the antiviral activity of 3 pro-nucleotides of the acyclic nucleoside analogues aciclovir (ACV), 3 of penciclovir (PCV) and 38 of the cyclic nucleoside analogue brivudin (BVDU), on the basis of cycloSaligenyl-nucleoside monophosphate approach against vaccinia virus and cowpox virus in vitro. In further experiments, 13 synthetic humic acid-like polymers, so-called polyhydroxycarboxylates, were examined.

Anti-HSV-1 activity of synthetic humic acid-like polymers derived from p-diphenolic starting compounds.

A panel of ten humic-acid-like polymers was synthesized by oxidation of p-diphenolic compounds and characterized by relative molecular weights, FT-IR spectra and functional group analysis. Using the XTT-based tetrazolium reduction assay EZ4U, both the low-molecular starting compounds and the synthesized polymers were examined for antiviral and cytotoxic activities in HSV-1-infected Vero cells. With the exception of hydroquinone, 2,5-dihydroxytoluene and 2,5-dihydroxybenzoquinone, the starting compounds failed to inhibit herpesvirus replication.

In vitro activity of polyhydroxycarboxylates against herpesviruses and HIV.

The antiviral activity of 17 polyhydroxycarboxylates derived from phenolic compounds was evaluated against herpesviruses and HIV. When present during virus adsorption several of the polymers exhibited potent activity against herpes simplex virus type 1 (HSV-1), HSV-2, thymidine kinase deficient HSV-1, human cytomegalovirus (HCMV) and HIV-1 and HIV-2 at concentrations that were not toxic to the host cells. A close correlation was found between the 50% inhibitory concentrations of the polyhydroxycarboxylates against HCMV-induced cytopathicity, their inhibitory effect on the expression of HCMV-specific immediate early antigens and their inhibitory effects on HCMV adsorption to the cells.