Opsoclonus-myoclonus-ataxia syndrome associated with central nervous system HIV-1 escape phenomenon. / Síndrome opsoclono-mioclono-ataxia asociado a fenómeno de escape viral por virus de la inmunodeficiencia humana en el sistema nervioso central.

INTRODUCTION: Opsoclonus-myoclonus-ataxia (OMA) syndrome is a rare neurological disorder characterized by involuntary conjugate saccadic eye movements, myoclonus, and ataxia. Few reports exist on patients with HIV and OMA. CASE REPORT: A 41-year-old man diagnosed with HIV-1 infection in 1997 coursed with multiple anti-retroviral schemes as a consequence of poor adherence. In 2008 he presented an HIV-1 viral load of 100,000 copies/mL and a CD4+ T cell count of 10 cells/mm3. In 2013 our patient arrived with an 11-month history of progressive opsoclonus and ataxia. He had undetectable plasma HIV-1 RNA load and CD4+ of 606 cells/mm3. No opportunistic infections were found. Cerebrospinal fluid analysis showed mildly elevated protein concentration and HIV-1 viral load of 534 copies/mL. Cerebrospinal fluid co-receptor tropism test showed selective CCR5 usage. A brain magnetic resonance imaging showed hippocampal atrophy and T2-weighted hyperintensities. Our patient exhibited a dramatic recovery and cerebrospinal fluid HIV clearance after adjustment of anti-retroviral treatment based on genotyping resistance and tropism analyses. CONCLUSIONS: In patients with HIV presenting cengral nervous system dysfunction without opportunistic infections, cerebro-spinal fluid and plasma HIV-1 viral load, resistance and tropism tests should be performed to assess a potential viral escape and to design the appropriate anti-retroviral therapy in an individual patient basis.

TITLE: Síndrome opsoclono-mioclono-ataxia asociado a fenómeno de escape viral por virus de la inmunodeficiencia humana en el sistema nervioso central.Introducción. El síndrome opsoclono-mioclono-ataxia (OMA) es un trastorno neurológico infrecuente caracterizado por movimientos oculares conjugados sacádicos involuntarios, mioclonías y ataxia. Existen pocos casos en la bibliografía de pacientes con virus de la inmunodeficiencia humana (VIH) y OMA. Caso clínico. Varón de 41 años y diagnóstico de infección por el VIH-1 desde 1997, que cursó con múltiples esquemas antirretrovirales debido a una pobre adhesión al tratamiento. En 2008 presentó una carga viral de 100.000 copias/mL y una cuenta linfocitaria CD4+ de 10 células/mm3. En 2013 sufrió un cuadro progresivo de 11 meses de evolución caracterizado por opsoclonía y ataxia. En ese momento, su carga viral era indetectable, y la cuenta de CD4+, de 606 células/mm3. Se descartaron infecciones oportunistas. El examen del líquido cefalorraquídeo demostró hiperproteinorraquia leve y una carga viral de 534 copias/mL. El examen del tropismo de correceptor en el líquido cefalorraquídeo demostró un uso selectivo de CCR5. La resonancia magnética cerebral objetivó atrofia hipocámpica e hiperintensidades en las secuencias ponderadas en T2. El paciente mostró una recuperación clínica franca y un aclaramiento de la carga viral en el líquido cefalorraquídeo tras el ajuste de antirretrovirales basado en la resistencia de genotipo y el análisis de tropismo. Conclusiones. En pacientes con infección por el VIH y disfunción del sistema nervioso central sin infecciones oportunistas, debería llevarse a cabo una determinación de la carga viral en el plasma y el líquido cefalorraquídeo para descartar un potencial fenómeno de escape viral, así como exámenes de resistencia y tropismo para diseñar el tratamiento antirretroviral adecuado.

CHELSI: a portable neutron spectrometer for the 20-800 MeV region.

CHELSI is a CsI-based portable spectrometer being developed at Los Alamos National Laboratory for use in high-energy neutron fields. Based on the inherent pulse shape discrimination properties of CsI(Tl), the instrument flags charged particle events produced via neutron-induced spallation events. Scintillation events are processed in real time using digital signal processing and a conservative estimate of neutron dose rate is made based on the charged particle energy distribution. A more accurate dose estimate can be made by unfolding the 2D charged particle versus pulse height distribution to reveal the incident neutron spectrum from which dose is readily obtained. A prototype probe has been assembled and data collected in quasi-monoenergetic fields at The Svedberg Laboratory (TSL) in Uppsala as well as at the Los Alamos Neutron Science Center (LANSCE). Preliminary efforts at deconvoluting the shape/energy data using empirical response functions derived from time-of-flight measurements are described.

Multisphere default spectra--solution spectrum and dosemeter response implications.

Initial calibration of a multisphere spectroscopy system has been completed at Los Alamos National Laboratory using four standard calibration scenarios. Spectrum unfolding was performed using three methods of constructing the default spectrum: simple parameter models, Monte Carlo calculations and physical measurement. Comparisons of the resulting spectra for each solution method are presented. Implications of the spectral solutions upon dosemeter characterisation are addressed.