Synaptic vesicles (SVs) from excitatory synapses carry vesicular glutamate transporters (VGLUTs) that fill the vesicles with neurotransmitter. Although the essential function of VGLUTs as glutamate transporters has been well established, the evidence for additional cell‐biological functions is more controversial. Both VGLUT1 and VGLUT2 disruptions in mice result in a reduced number of SVs away from release sites, flattening of SVs, and the appearance of tubular structures. Therefore, we analysed the morphology, biochemical composition and trafficking of SVs at synapses of VGLUT1?/? mice in order to test for a function of VGLUTs in the formation or clustering of SVs. Analyses with high‐pressure freezing immobilisation and electron tomography pointed to a role of VGLUT1 transport function in the tonicity of excitatory SVs, explaining the aldehyde‐induced flattening of SVs observed in VGLUT1?/? synapses. We confirmed the steep reduction in the number of SVs previously observed in VGLUT1?/? presynaptic terminals, but did not observe accumulation of endocytotic intermediates. Furthermore, SV proteins of adult VGLUT1?/? mouse brain tissue were expressed at normal levels in all subcellular fractions, suggesting that they were not displaced to another organelle. We thus assessed the mobility of the recently documented superpool of SVs. Synaptobrevin2–enhanced green fluorescent protein time lapse experiments revealed an oversized superpool of SVs in VGLUT1?/? neurons. Our results support the idea that, beyond glutamate loading, VGLUT1 enhances the tonicity of excitatory SVs and stabilises SVs at presynaptic terminals. 相似文献
This article reviews theoretical and practical approaches for setting priorities in global child health research investments. It also provides an overview of previous attempts to develop appropriate tools and methodologies to define priorities in health research investments. A brief review of the most important theoretical concepts that should govern priority setting processes is undertaken, showing how different perspectives, such as medical, economical, legal, ethical, social, political, rational, philosophical, stakeholder driven, and others will necessarily conflict each other in determining priorities. We specially address present research agenda in global child health today and how it relates to United Nation's (UN) Millennium Development Goal 4, which is to reduce child mortality by two-thirds between 1990 and 2015. The outcomes of these former approaches are evaluated and their benefits and shortcomings presented. The case for a new methodology for setting priorities in health research investments is presented, as proposed by Child Health and Nutrition Research Initiative, and a need for its implementation in global child health is outlined. A transdisciplinary approach is needed to address all the perspectives from which investments into health research can be seen as priorities. This prioritization requires a process that is transparent, systematic, and that would take into account many perspectives and build on advantages of previous approaches. 相似文献
West Nile virus (WNV) is a Flavivirus attracting worldwide attention because it has spread rapidly across the Americas since its first appearance in New York City in 1999. Several PCR-based diagnostic methods have been developed for the detection of WNV. The focus of these assays has been WNV lineage 1 which can be found worldwide, while lineage 2 viruses were thought to be endemic only in some regions of Africa. However, both lineages may be imported from Africa to Europe by migrating birds. In order to determine the incidence of WNV in Germany, a real-time-based PCR assay was developed, targeting a conserved region of WNV lineages 1 and 2. This assay is a suitable tool for the diagnosis of WNV and for surveillance studies. 相似文献
Treatment landscape in prostate cancer has changed dramatically with the emergence of new medicines in the past few years. The traditional survival partition model (SPM) cannot accurately predict long-term clinical outcomes because it is limited by its ability to capture the key consequences associated with this changing treatment paradigm. The objective of this study was to introduce and validate a discrete-event simulation (DES) model for prostate cancer.
Methods
A DES model was developed to simulate overall survival (OS) and other clinical outcomes based on patient characteristics, treatment received, and disease progression history. We tested and validated this model with clinical trial data from the abiraterone acetate phase III trial (COU-AA-302). The model was constructed with interim data (55% death) and validated with the final data (96% death). Predicted OS values were also compared with those from the SPM.
Results
The DES model’s predicted time to chemotherapy and OS are highly consistent with the final observed data. The model accurately predicts the OS hazard ratio from the final data cut (predicted: 0.74; 95% confidence interval [CI] 0.64–0.85 and final actual: 0.74; 95% CI 0.6–0.88). The log-rank test to compare the observed and predicted OS curves indicated no statistically significant difference between observed and predicted curves. However, the predictions from the SPM based on interim data deviated significantly from the final data.
Conclusions
Our study showed that a DES model with properly developed risk equations presents considerable improvements to the more traditional SPM in flexibility and predictive accuracy of long-term outcomes. 相似文献
The National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention conducted a workshop in January 2006, entitled "Prioritizing a Research Agenda for Orofacial Clefts." The goals of the meeting were to review existing research on orofacial clefts (OFCs), identify gaps in knowledge that need additional public health research, and develop a prioritized research agenda that can help guide future public health research. Experts in the field of epidemiology, public health, genetics, psychology, speech pathology, dentistry, and health economics participated to create the research agenda. Research gaps identified by the participants for additional public health research included: the roles of maternal nutrition, obesity, and diabetes in the etiology of OFCs; psychosocial outcomes for children with OFCs; the quality of life for families and children with OFCs; and the health care costs of OFCs. To create the research agenda, the participants prioritized the research gaps by public health importance, feasibility, and outcomes of interest. This report summarizes the workshop. 相似文献
Gastro-oesophageal reflux disease (GORD) after one anastomosis gastric bypass (OAGB) remains a concern. We reviewed the current literature on revisional surgery after OAGB for GORD. MEDLINE, EMBASE, and PubMed databases were searched. We identified 21 studies, appraising 13,658 OAGB patients. A total of 230 (1.6%) patients underwent revisional surgery for GORD. Revision to Roux-en-Y configuration was performed in 211 (91.7%) patients. Six (2.6%) patients had a Braun entero-enterostomy added to the OAGB. Thirteen (5.6%) patients underwent excluded stomach fundoplication (ESF). Reflux symptoms resolved in 112 (48.6%) patients, persisted in 13 (5.6%) patients, and were not reported in 105 (45.6%) patients. Revisional surgery after OAGB for GORD appears to be rare, and when required, conversion to Roux-en-Y configuration is the commonest choice.