Oxidative metabolism of the human eosinophil

We have compared the oxidative metabolism of human eosinophils (80%-90% purity) to that of neutrophils. Hexose monophosphate (HMP) shunt activity of eosinophils was higher than that of neutrophils under either resting or phagocytizing conditions. Eosinophil HMP shunt activity also was stimulated by phorbol myristate acetate, a membrane- active agent. Eosinophils showed a marked incorporation of 125I into trichloroacetic acid-insoluble material under resting conditions, which increased markedly during phagocytosis. Eosinophils likewise showed a greater reduction of nitroblue tetrazolium dye during phagocytosis than did neutrophils. Measurement of other parameters of oxidative metabolism indicated that eosinophils generated superoxide anion following phagocytosis and also elicited a burst of chemiluminescence similar to that observed during phagocytosis by neutrophils. Measurement of NADPH oxidase activity demonstrated that this enzyme was 3-6 times more active in fractions isolated from eosinophils than in corresponding fractions isolated from neutrophils; this was observed over a range of substrate concentrations. The eosinophil enzyme sedimented differently than the neutrophil enzyme with differential centrifugation; neither showed sedimentation characteristics of peroxidase. These data indicate that eosinophils possess a similar, although in some ways more potent, oxidative burst than neutrophils and are consistent with a role for NADPH oxidase in the initiation of that burst.     

Whom Should I Refer in 2014 for Cardiac Resynchronization?

Heart failure continues to be a significant source of morbidity and mortality amongst Canadians. Many patients remain symptomatic despite guideline-directed medical therapy. For drug-refractory patients with dyssynchronous systolic heart failure, cardiac resynchronization therapy (CRT) has reliably reduced heart failure hospitalizations and related deaths. Unfortunately, despite significant advancements in technology and our understanding of its clinical effect, the CRT nonresponder rate remains approximately 30%. Great efforts have been invested into identifying clinical predictors of CRT response. Left bundle branch block conduction delay and wider QRS (> 150 ms) have consistently been associated with clinical response to CRT, earning them the strongest recommendations in the revised guidelines in Canada and across the world. Due in large part to the benefit observed in the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT) trial, patients with mild heart failure symptoms (New York Heart Association class II) are now also candidates for resynchronization therapy. Patients with atrial fibrillation, non-left bundle branch block conduction patterns, and chronic right ventricular pacing have historically been associated with poor response. However, these populations remain grossly underrepresented in the large trials. In the absence of more data, these patients continue to receive weaker recommendations for CRT in the guidelines.     

Absence of IFNγ expression induces neuronal degeneration in the spinal cord of adult mice

Background  

Interferon gamma (IFNγ) is a pro-inflammatory cytokine, which may be up-regulated after trauma to the peripheral or central nervous system. Such changes include reactive gliosis and synaptic plasticity that are considered important responses to the proper regenerative response after injury. Also, IFNγ is involved in the upregulation of the major histocompatibility complex class I (MHC class I), which has recently been shown to play an important role in the synaptic plasticity process following axotomy. There is also evidence that IFNγ may interfere in the differentiation and survival of neuronal cells. However, little is known about the effects of IFNγ absence on spinal cord neurons after injury.     

TDI技术评价卡维地洛对高血压患者左室舒张功能的影响

目的:应用组织多普勒显像(TDI)技术评价卡维地洛对高血压患者左室舒张功能的影响.方法:对30例高血压给予卡维地洛治疗24周.治疗前、治疗后12周、24周用TDI技术测量左室收缩期二尖瓣环平均舒张早期运动速度(Ea)、舒张晚期运动速度(Aa)及Ea/Aa,并与血流多普勒指标E波速度(E)、A波速度(A)、E/A进行比较,观察降压效果及对左室舒张功能的影响.结果:卡维地洛治疗12周后收缩压(SBP)、舒张压(DBP)、心率(HR)均较治疗前下降(P＜0.05),Ea、Ea/Aa均较治疗前升高(P＜0.05),治疗24周后E、E/A较治疗前升高(P＜0.05),Aa较治疗前降低(P＜0.05),Ea、Ea/Aa有进一步改善的趋势(P＜0.05).结论:TDI技术在评价左室舒张功能方面较二尖瓣血流频谱更敏感;卡维地洛对轻、中度高血压具有良好的降压作用,且能改善患者左室舒张功能.     

PCR colorimetric dot-blot assay and clinical pretest probability for diagnosis of Pulmonary Tuberculosis in Smear-Negative patients

Background  

Smear-negative pulmonary tuberculosis (SNPTB) accounts for 30% of Pulmonary Tuberculosis (PTB) cases reported annually in developing nations. Polymerase chain reaction (PCR) may provide an alternative for the rapid detection of Mycobacterium tuberculosis (MTB); however little data are available regarding the clinical utility of PCR in SNPTB, in a setting with a high burden of TB/HIV co-infection.     

TDI技术评价卡维地洛对高血压患者左室舒张功能的影响

目的:应用组织多普勒显像(TDI)技术评价卡维地洛对高血压患者左室舒张功能的影响.方法:对30例高血压给予卡维地洛治疗24周.治疗前、治疗后12周、24周用TDI技术测量左室收缩期二尖瓣环平均舒张早期运动速度(Ea)、舒张晚期运动速度(Aa)及Ea/Aa,并与血流多普勒指标E波速度(E)、A波速度(A)、E/A进行比较,观察降压效果及对左室舒张功能的影响.结果:卡维地洛治疗12周后收缩压(SBP)、舒张压(DBP)、心率(HR)均较治疗前下降(P＜0.05),Ea、Ea/Aa均较治疗前升高(P＜0.05),治疗24周后E、E/A较治疗前升高(P＜0.05),Aa较治疗前降低(P＜0.05),Ea、Ea/Aa有进一步改善的趋势(P＜0.05).结论:TDI技术在评价左室舒张功能方面较二尖瓣血流频谱更敏感;卡维地洛对轻、中度高血压具有良好的降压作用,且能改善患者左室舒张功能.