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.     

Centre-specific or average unit costs in multi-centre studies? Some theory and simulation

Costing issues are increasingly being addressed in multi-centre studies. In this paper, two methods for collecting costing information are compared within a simulated clinical trial setting. One method estimates average treatment costs by applying unit costs averaged across treatment centres to centre-specific volumes of resource use. The second uses centre-specific information for both the unit costs and the resource volumes, and then averages across centres. Using a pre-specified production relation between the different volumes of resource use, and simulating changes in unit costs, it is shown that these two methods result in statistically different estimates of average treatment costs. This finding holds, regardless of the degree of substitutability between the resource volumes, except when considerable uncertainty surrounds treatment centre responses to relative changes in unit costs. The findings suggest that a more cautious approach should be adopted in the collection, calculation and interpretation of treatment costs in multi-centre studies.     

Informing environmental health policy in urban areas: the HEADLAMP approach

Urban areas represent complex environments in which to protect health. Accurate and highly resolved information is thus a prerequisite for effective environmental health policy. The HEADLAMP approach is designed to improve decision-making by providing indicators, based on sound science, to all relevant stakeholders, in an appropriate and usable form. The approach comprises three linked stages: categorization of the issues to be addressed, construction of relevant indicators, and policy formulation and implementation. Nevertheless, the application of this approach faces many challenges. The environment-health chain is both lengthy and complex, so that a wide range of indicators is needed from different points in this chain. The DPSEEA framework provides a useful, though limited, structure to help define and organize these indicators. This complexity also means that the indicators have to be linked, so that problems can be tracked from cause to effect and the effectiveness of actions at different points in the DPSEEA chain can be evaluated. Indicators also have to be designed in ways reflecting the spatial and temporal complexity of urban areas--namely, the rapid rates of change in urban environments and the marked spatial variations in environmental and sociodemographic conditions. Effective methods of participation are equally essential if the indicators are to represent the concerns of the stakeholders involved, and if decisions are to be made on a collective basis. Good indicators thus must be designed to fit many different and varying purposes. The challenge is to devise indicators that serve these purposes by representing the intricacies that are inherent in urban areas, rather than by hiding that complexity.     

31P nuclear magnetic resonance study of the effect of hypoxemia on neonatal status epilepticus

Prolonged neonatal seizures are often accompanied or exacerbated by hypoxemia. To determine the effects of hypoxemia on neonatal status epilepticus, we determined cerebral blood flow and cerebral metabolic state in groups of neonatal dogs subjected to hypoxia, to seizures during normoxia, or to seizures during hypoxia. The compensatory increase in cerebral blood flow was greatest in animals subjected to seizures during normoxia and somewhat less pronounced in animals made hypoxic. However, blood flow failed to increase in forebrain structures when animals were subjected to the combination of seizures and hypoxia. Accordingly, levels of adenosine triphosphate in forebrain (measured both by in vitro enzymatic analysis and by in vivo phosphorus-31 nuclear magnetic resonance spectroscopy) were depleted to the greatest degree in animals who were seizing while hypoxic. In addition, brain glucose was significantly reduced only in the seizure-hypoxia group. Systemic factors such as hypoxemia may play a critical role in the disruption of cerebral energy balance during neonatal status epilepticus.