Characterization of unilateral conjunctival inoculation with Mycoplasma gallisepticum in house finches

House finches in much of the continental United States experience annual epidemics of mycoplasmal conjunctivitis, caused by the bacterial pathogen Mycoplasma gallisepticum (MG). Although evidence suggests that natural infections typically begin unilaterally, experimental inoculations of songbirds with MG to date have all been administered bilaterally. Furthermore, studies of free-living finches find more severe clinical signs of mycoplasmal conjunctivitis in left versus right eyes, but the mechanisms underlying this side bias remain unknown. Here, we characterized unilateral inoculation of house finches with MG, and tested whether differential susceptibility of left versus right conjunctiva explains the side bias in disease severity of free-living finches. We directly inoculated house finches in either the left or right conjunctiva and characterized resulting disease severity and pathogen load throughout the course of infection. As expected, unilateral inoculation resulted in significantly more severe conjunctivitis, as well as higher conjunctival bacterial loads, on whichever side (left or right) birds were directly inoculated. However, in 55% of cases, unilateral inoculations resulted in bilateral disease, and in 85% cases there was evidence of bilateral infection. The overall severity of disease did not differ for birds inoculated in the left versus right conjunctiva, suggesting that physiological differences between the conjunctivae cannot explain the side bias in disease severity of free-living birds. Instead, laterality in exposure, perhaps due to feeding handedness, likely explains the detected field patterns.

RESEARCH HIGHLIGHTS

• House finches show more severe disease in the directly inoculated conjunctiva.

• Unilateral inoculations lead to high rates of bilateral infection and disease.

• Overall disease severity does not differ for the left- or right-inoculated conjunctiva.

• Laterality in exposure likely explains the left-side bias in natural infections.

     

Unresolved questions regarding human hereditary deafness

Human hearing loss is a common neurosensory disorder about which many basic research and clinically relevant questions are unresolved. This review on hereditary deafness focuses on three examples considered at first glance to be uncomplicated, however, upon inspection, are enigmatic and ripe for future research efforts. The three examples of clinical and genetic complexities are drawn from studies of (i) Pendred syndrome/DFNB4 (PDS, OMIM 274600), (ii) Perrault syndrome (deafness and infertility) due to mutations of CLPP (PRTLS3, OMIM 614129), and (iii) the unexplained extensive clinical variability associated with TBC1D24 mutations. At present, it is unknown how different mutations of TBC1D24 cause non‐syndromic deafness (DFNB86, OMIM 614617), epilepsy (OMIM 605021), epilepsy with deafness, or DOORS syndrome (OMIM 220500) that is characterized by d eafness, o nychodystrophy (alteration of toenail or fingernail morphology), o steodystrophy (defective development of bone), mental r etardation, and s eizures. A comprehensive understanding of the multifaceted roles of each gene associated with human deafness is expected to provide future opportunities for restoration as well as preservation of normal hearing.     

涂阳肺结核患者诊断延误及影响因素分析

目的对2009年10~12月武汉市结核病防治所住院的痰标本直接涂片抗酸杆菌镜检阳性(涂阳)肺结核患者诊断延误及其影响因素进行研究。方法采用自行设计的问卷,对224例涂阳肺结核患者进行面访式调查。采用Wilcoxon符号秩和检验对首诊延误、卫生系统延误及诊断延误分别进行单因素分析,用逐步logistic回归法对3种延误分别进行多因素分析。结果首诊延误、卫生系统延误及诊断延误中位数分别为8、12及35 d;首诊延误的危险因素为:男性(OR=2.134,95%可信区间1.115~4.083),初中及以下文化(OR=1.879,95%可信区间1.048~3.368),无咯血(OR=2.194,95%可信区间1.056~4.559)及结核知识得分低(OR=4.060,95%可信区间2.232~7.385);卫生系统延误危险因素为:首诊为区以下医疗单位(OR=2.938,95%可信区间1.339~6.446),保护因素为:就诊次数≤1次(OR=0.056,95%可信区间0.025~0.126);诊断延误危险因素为结核知识得分低(OR=3.036,95%可信区间1.654~5.572),自卑及自我羞耻感水平高(OR=2.012,95%可信区间1.103~3.676),保护因素为:就诊次数≤1次(OR=0.216,95%可信区间0.117~0.396)。结论武汉市住院涂阳肺结核患者存在一定的诊断延误,但延误水平不高。应加强对人群特别是文化程度低的人群的结核相关知识宣教;加强基层医务人员对结核病的警觉性并提高诊断能力;应避免患者反复多次就诊于同一水平医疗机构,从而缩短诊断延误时间。     

Antiretroviral therapy in prevention of HIV and TB: update on current research efforts

There is considerable scientific evidence supporting the use of antiretroviral therapy (ART) in prevention of human immunodeficiency virus (HIV) and tuberculosis (TB) infections. The complex nature of the HIV and TB prevention responses, resource constraints, remaining questions about cost and feasibility, and the need to use a solid evidence base to make policy decisions, and the implementation challenges to translating trial data to operational settings require a well-organised and coordinated response to research in this area. To this end, we aimed to catalogue the ongoing and planned research activities that evaluate the impact of ART plus other interventions on HIV- and/or TB-related morbidity, mortality, risk behaviour, HIV incidence and transmission. Using a limited search methodology, 50 projects were identified examining ART as prevention, representing 5 regions and 52 countries with a global distribution. There are 24 randomised controlled clinical trials with at least 12 large randomised individual or community cluster trials in resource-constrained settings that are in the planning or early implementation stages. There is considerable heterogeneity between studies in terms of methodology, interventions and geographical location. While the identified studies will undoubtedly advance our understanding of the efficacy and effectiveness of ART for prevention, some key questions may remain unanswered or only partially answered. The large number and wide variety of research projects emphasise the importance of this research issue and clearly demonstrate the potential for synergies, partnerships and coordination across funding agencies.