RESUMEN
A systematic search of Medline, EMBASE and CINAHL electronic databases was performed. Original research articles reporting all-cause mortality following surgery in patients with aortic regurgitation and severe left ventricular systolic dysfunction (LVSD) were identified. Nine of the 10 eligible studies were observational, single-center, retrospective analyses. Survival ranged from 86 to 100% at 30 days; 81 to 100% at 1 year and 68 to 84% at 5 years. Three studies described an improvement in mean left ventricular ejection fraction (LVEF) following aortic valve replacement (AVR) of 5-14%; a fourth study reported an increase in mean left ventricular ejection fraction (LVEF) of 9% in patients undergoing isolated AVR but not when AVR was combined with coronary artery bypass graft and/or mitral valve surgery. Three studies demonstrated improvements in functional New York Heart Association (NYHA) class following AVR. Additional studies are needed to clarify the benefits of AVR in patients with more extreme degrees of left ventricular systolic dysfunction (LVSD) and the potential roles of cardiac transplantation and transaortic valve implantation.
Asunto(s)
Insuficiencia de la Válvula Aórtica/terapia , Disfunción Ventricular Izquierda/terapia , Insuficiencia de la Válvula Aórtica/complicaciones , Humanos , Estudios Retrospectivos , Disfunción Ventricular Izquierda/complicacionesRESUMEN
This study evaluated the use of house sparrow (Passer domesticus) nestlings as sentinels of West Nile virus (WNV) in the prairie grasslands of Saskatchewan. In the summer of 2006, 600 house sparrow nestlings were collected and pooled tissues tested by reverse transcriptase-polymerase chain reaction. All tested negative for WNV. During the same period, no WNV was detected by mosquito surveillance in the study area and 15 WNV-infected pools were collected from the nearby city of Estevan. Six percent of avian carcasses collected from Regina, a city 100 km from the study area in the same ecozone, were infected with WNV. In 2007, 200 house sparrow nestlings were collected and 4 tested positive for WNV, a prevalence of 2%. Ninety-seven house sparrow eggs were also collected and WNV antibodies were measured in the yolk. Seven eggs had measurable titers, a prevalence of 7.2%. Combined WNV surveillance showed high levels of WNV transmission in 2007; 112 WNV-infected mosquito pools were collected from nearby cities of Estevan and Weyburn, and the proportion of WNV infected avian carcasses from Regina was 78%. There were 1456 human cases of WNV in Saskatchewan in 2007, compared to 19 cases in 2006. The study concluded that house sparrow nestlings are not useful as an early warning of WNV circulation, or as a measure of the intensity of WNV activity in the prairie grasslands. Also, the study determined that maternally derived antibody did not have a significant limiting effect on WNV transmission to house sparrow nestlings in 2007, a year of epidemic WNV activity in the study area.
Asunto(s)
Vigilancia de Guardia , Gorriones/virología , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/aislamiento & purificación , Animales , Anticuerpos Antivirales/sangre , Reacción en Cadena de la Polimerasa , Saskatchewan/epidemiología , Gorriones/sangre , Fiebre del Nilo Occidental/epidemiología , Virus del Nilo Occidental/inmunologíaRESUMEN
This study examines health care personnel's knowledge of West Nile virus (WNv) and attitudes towards a proposed chimeric yellow fever/WNv vaccine within the province of Saskatchewan. Telephone and in-person interviews with medical health officers and public health nurses provided information with which to assess the acceptability of implementing vaccination as a component for prevention of WNv within the province with the highest number of WNv cases to date in western Canada. The majority of health care professionals felt confident in the potential efficacy of vaccination for prevention of WNv but suggested that targeted vaccination programs could be most effective.