Biochemical and inflammatory biomarkers in ischemic stroke: translational study between humans and two experimental rat models.

BACKGROUND: our objective was to examine the plasma levels of three biological markers involved in cerebral ischemia (IL-6, glutamate and TNF-alpha) in stroke patients and compare them with two different rat models of focal ischemia (embolic stroke model- ES and permanent middle cerebral artery occlusion ligation model-pMCAO) to evaluate which model is most similar to humans. SECONDARY OBJECTIVES: 1) to analyze the relationship of these biological markers with the severity, volume and outcome of the brain infarction in humans and the two stroke models; and 2) to study whether the three biomarkers are also increased in response to damage in organs other than the central nervous system, both in humans and in rats. METHODS: Multi-center, prospective, case-control study including acute stroke patients (n=58) and controls (n=19) with acute non-neurological diseases MAIN VARIABLES: plasma biomarker levels on admission and at 72 h; stroke severity (NIHSS scale) and clinical severity (APACHE II scale); stroke volume; functional status at 3 months (modified Rankin Scale [mRS] and Barthel index [BI]). Experimental groups: ES (n=10), pMCAO (n=6) and controls (tissue stress by leg compression) (n=6). MAIN VARIABLES: plasma biomarker levels at 3 and 72 h; volume of ischemic lesion (H&E) and cell death (TUNEL). RESULTS: in stroke patients, IL-6 correlated significantly with clinical severity (APACHE II scale), stroke severity (NIHSS scale), infarct volume (cm3) and clinical outcome (mRS) (r=0.326, 0.497, 0.290 and 0.444 respectively; P<0.05). Glutamate correlated with stroke severity, but not with outcome, and TNF-alpha levels with infarct volume. In animals, The ES model showed larger infarct volumes (median 58.6% vs. 29%, P<0.001) and higher inflammatory biomarkers levels than pMCAO, except for serum glutamate levels which were higher in pMCAO. The ES showed correlations between the biomarkers and cell death (r=0.928 for IL-6; P<0.001; r=0.765 for TNF-alpha, P<0.1; r=0.783 for Glutamate, P<0.1) and infarct volume (r=0.943 for IL-6, P<0.0001) more similar to humans than pMCAO. IL-6, glutamate and TNF-α levels were not higher in cerebral ischemia than in controls. CONCLUSIONS: Both models, ES and pMCAO, show differences that should be considered when conducting translational studies. IL-6, Glutamate and TNF-α are not specific for cerebral ischemia either in humans or in rats.

In-hospital stroke treated with intravenous tissue plasminogen activator.

BACKGROUND AND PURPOSE: In-hospital strokes (IHSs) are potential candidates for thrombolysis. We analyzed the treatment procedures, safety, and efficacy of intravenous tissue plasminogen activator (IV-tPA) in IHSs compared with out-of-hospital strokes (OHSs). METHODS: This study was based on a multicenter prospective registry of patients treated with IV-tPA divided into IHSs and OHSs. We recorded intrahospital delays and stroke outcomes. RESULTS: Among 367 patients treated with IV-tPA, 30 were IHSs. Baseline characteristics were similar except for a greater proportion of diabetes (36.7% vs 17.5%, P=0.01), cardiac failure (16.7% vs 5.3%, P=0.014), and atrial fibrillation (33.3% vs 17.5%, P=0.034) in IHSs than OHSs. In-hospital delays were significantly longer in IHSs for door-to-computed tomography time (39.5+/-18.7 vs 22.6+/-19.7 minutes, P<0.0001) and computed tomography-to-treatment time (92.0+/-26.1 vs 65.4+/-25.8 minutes, P<0.0001). No differences were observed in safety or efficacy. CONCLUSIONS: In-hospital procedures for thrombolysis proceed more slowly in IHSs than in OHSs. Thrombolysis is safe and efficient in IHS.

Infección por el virus de hepatitis C: seroprevalencia en pacientes infectados por el virus de inmunodeficiencia humana / Infection for the hepatitis virus C: in seroprevalence patients infected by the virus of human immunodeficience

Estudiar en forma prospectiva la prevalencia de coinfección por el virus de inmonodeficiencia humana, así como las conductas y factores de riesgo presentes en estos pacientes. La muestra estuvo constituida por la todos los pacientes masculinos y femeninos con evidencia serológica de infección por virus de inmunodeficiencia humana, mayores de 15 años, independientemente de su estadio clínico o grado de inmunosupresión, de la consulta externa de infectología y los servicios de hospitalización del Hospital Vargas de Caracas, y a la consulta de inmunología clínica del Instituto Venezolano de los Seguros Sociales. Se utilizó un método de inmunoensayo enzimático (ELIZA) de 3a generación (kits de diagnóstico Murexanti-VHC versión 4.0 de Abbott) para la detección de anticuerpos contra el virus de hepatitis C presentes en el suero. A los pacientes que resultaron con serología positiva, se les realizó una prueba confirmatoria mediante determinación cuantitativa de RNA viral con técnicas de reacción en cadena por polimerasa (PCR) (kits Cobas Amplicor HCV versión 2.0) y determinación de genotipos de virus de hepatitis C. Se incluyeron 777 pacientes. La edad media fue 39,51 años y el 85,4 por ciento fueron hombres. La serología para el virus de hepatitis C resultó positiva en 2,7 por ciento de los individuos. Las siguientes variables se asociaron con un aumento en la prevalencia de coinfección: uso de drogas parenterales, hemofilia y realización de tatuajes (todas con una P< 0,05). El genotipo más frecuente correspondió al genotipo 1. La seroprevalencia de coinfección hepatitis C virus de inmunodeficeincia humana en Venezuela no resulta tan elevada al compararla con la literatura internacional, determinándose en este estudio en un valor de 2,7 por ciento. Debe realizarse de forma rutinaria la determinación de anticuerpos anti.VHC en individuos con virus de inmunodeficiencia humana y, especialmente, en aquellos con factores de riesgo como tatuajes, uso de drogas ilícitas...