RESUMEN
La estenosis aórtica severa sintomática secundaria a calcificación degenerativa constituye un reto terapéutico si el paciente no es tributario de tratamiento quirúrgico de reemplazo valvular. La colocación de un implante valvular aórtico transcatéter (TAVI) es una alternativa terapéutica para estos casos. Se presenta el caso de un varón de 78 años con antecedentes de hipertensión arterial, enfermedad renal crónica (estadio IIIa), tabaquismo pesado, portador de marcapaso definitivo, enfermedad arterial periférica y policitemia vera. A la evaluación, el paciente cursaba con una disnea de clase III (escala NYHA) desde hace un año. El ecocardiograma transtorácico mostró calcificación severa de velos aórticos, una fracción de eyección ventricular izquierda de 44,7% y un área valvular de 0,58 cm2 (0,31 cm2/m2); la angiografía mostró enfermedad arterial coronaria moderada y la angiotomografía una calcificación severa de la aorta torácica ('aorta en porcelana'). Por considerarlo de alto riesgo, se realizó colocación de TAVI por vía transapical (válvula bioprotésica Braile Biomédica N° 30), con controles ecocardiográficos satisfactorios. El caso que presentamos constituye el primero realizado en el norte del país
Severe symptomatic aortic stenosis secondary to degenerative calcification may be a real therapeutic challenge if the patient does not undergo an aortic valve replacement. Transapical transcatheter aortic valve replacement is a valid therapeutic option for these cases. We present the case of a 78-year old male with the following past and current medical history: high blood pressure, chronic kidney disease (stage IIIa), heavy tobacco smoking, use of a permanent pacemaker, peripheral arterial disease, and polycythemia vera. When assessed, the patient had had class III heart failure (NYHA classification) for one year. Transthoracic ultrasonography showed severe calcification of the aortic cusps, a 44.7% left ventricular ejection fraction, and a 0.58 cm2 (0.31 cm2/m2) valve surface area. Angiography showed moderate coronary heart disease, and angiotomography showed severe calcification of the aortic valve ('porcelain aorta'). Since this patient was considered at high-risk, a transapical transcatheter aortic valve replacement was performed (Braille Biomedical N° 30 bioprosthetic valve), and the ultrasonography controls showed satisfactory results. This case is the first procedure of its kind performed in Northern Peru
RESUMEN
Rhesus macaques infected with the WE strain of lymphocytic choriomeningitis virus (LCMV-WE) serve as a model for human infection with Lassa fever virus. To identify the earliest events of acute infection, rhesus macaques were monitored immediately after lethal infection for changes in peripheral blood mononuclear cells (PBMCs). Changes in CD3, CD4, CD8 and CD20 subsets did not vary outside the normal fluctuations of these blood cell populations; however, natural killer (NK) and γδ T cells increased slightly on day 1 and then decreased significantly after two days. The NK subsets responsible for the decrease were primarily CD3-CD8+ or CD3-CD16+ and not the NKT (primarily CD3+CD56+) subset. Macaques infected with a non-virulent arenavirus, LCMV-Armstrong, showed a similar drop in circulating NK and γδ T cells, indicating that this is not a pathogenic event. V³9 T cells, representing the majority of circulating γδ T cells in rhesus macaques, displayed significant apoptosis when incubated with LCMV in cell culture; however, the low amount of cell death for virus-co-cultured NK cells was insufficient to account for the observed disappearance of this subset. Our observations in primates are similar to those seen in LCMV-infected mice, where decreased circulating NK cells were attributed to margination and cell death. Thus, the disappearance of these cells during acute hemorrhagic fever in rhesus macaques may be a cytokine-induced lymphopenia common to many virus infections.