The synergy between TB and HIV co-infection on perceived stigma in Ethiopia

<p>Abstract</p> <p>Background</p> <p>The synergy between tuberculosis (TB) and human immunodeficiency virus (HIV) co-infection on perceived stigma is not well studied. The objective of this study was to assess the effect of TB/HIV co-infection on perceived stigma in selected hospitals of Oromiya region, Ethiopia. A cross sectional study was conducted from February to April, 2009 in Adama, Nekemet and Jimma Specialized hospitals. Data were collected by trained HIV counselors. A structured questionnaire which consisted of socio-demographic variables, clinical information, perceived stigma, and depression was used to collect the data</p> <p>Findings</p> <p>A total of 591 participants were included in the study of whom 124 (20.9%) were co-infected with TB/HIV. The stigma items were highly reliable (Cronbach's alpha = 0.93) and had strong inter dimension correlation. Respondents who were co-infected with TB and HIV were more likely to have perceived stigma compared to non-co-infected HIV patients, [OR = 1.4, (95% CI: 1.2, 2.0)]. Non-literate individuals [OR = 1.9, (95% CI: 1.2, 3.0)] and females [OR = 1.6, (95% CI: 1.2, 2.3)] had also more perceived stigma.</p> <p>Conclusions</p> <p>TB/HIV co-infected patients, non-literate individuals and females were more likely to have high perceived stigma. Behavioral Change Communication should focus on these segments of the population to rectify the high perceived stigma.</p

Tandemly repeated DNA families in the mouse genome

<p>Abstract</p> <p>Background</p> <p>Functional and morphological studies of tandem DNA repeats, that combine high portion of most genomes, are mostly limited due to the incomplete characterization of these genome elements. We report here a genome wide analysis of the large tandem repeats (TR) found in the mouse genome assemblies.</p> <p>Results</p> <p>Using a bioinformatics approach, we identified large TR with array size more than 3 kb in two mouse whole genome shotgun (WGS) assemblies. Large TR were classified based on sequence similarity, chromosome position, monomer length, array variability, and GC content; we identified four superfamilies, eight families, and 62 subfamilies - including 60 not previously described. 1) The superfamily of centromeric minor satellite is only found in the unassembled part of the reference genome. 2) The pericentromeric major satellite is the most abundant superfamily and reveals high order repeat structure. 3) Transposable elements related superfamily contains two families. 4) The superfamily of heterogeneous tandem repeats includes four families. One family is found only in the WGS, while two families represent tandem repeats with either single or multi locus location. Despite multi locus location, TRPC-21A-MM is placed into a separated family due to its abundance, strictly pericentromeric location, and resemblance to big human satellites.</p> <p>To confirm our data, we next performed <it>in situ </it>hybridization with three repeats from distinct families. TRPC-21A-MM probe hybridized to chromosomes 3 and 17, multi locus TR-22A-MM probe hybridized to ten chromosomes, and single locus TR-54B-MM probe hybridized with the long loops that emerge from chromosome ends. In addition to <it>in silico </it>predicted several extra-chromosomes were positive for TR by <it>in situ </it>analysis, potentially indicating inaccurate genome assembly of the heterochromatic genome regions.</p> <p>Conclusions</p> <p>Chromosome-specific TR had been predicted for mouse but no reliable cytogenetic probes were available before. We report new analysis that identified <it>in silico </it>and confirmed <it>in situ </it>3/17 chromosome-specific probe TRPC-21-MM. Thus, the new classification had proven to be useful tool for continuation of genome study, while annotated TR can be the valuable source of cytogenetic probes for chromosome recognition.</p

A Role for Calcium-Permeable AMPA Receptors in Synaptic Plasticity and Learning

A central concept in the field of learning and memory is that NMDARs are essential for synaptic plasticity and memory formation. Surprisingly then, multiple studies have found that behavioral experience can reduce or eliminate the contribution of these receptors to learning. The cellular mechanisms that mediate learning in the absence of NMDAR activation are currently unknown. To address this issue, we examined the contribution of Ca[superscript 2+]-permeable AMPARs to learning and plasticity in the hippocampus. Mutant mice were engineered with a conditional genetic deletion of GluR2 in the CA1 region of the hippocampus (GluR2-cKO mice). Electrophysiology experiments in these animals revealed a novel form of long-term potentiation (LTP) that was independent of NMDARs and mediated by GluR2-lacking Ca2+-permeable AMPARs. Behavioral analyses found that GluR2-cKO mice were impaired on multiple hippocampus-dependent learning tasks that required NMDAR activation. This suggests that AMPAR-mediated LTP interferes with NMDAR-dependent plasticity. In contrast, NMDAR-independent learning was normal in knockout mice and required the activation of Ca[superscript 2+]-permeable AMPARs. These results suggest that GluR2-lacking AMPARs play a functional and previously unidentified role in learning; they appear to mediate changes in synaptic strength that occur after plasticity has been established by NMDARs.National Health and Medical Research Council (Australia) (Grant number 188819)National Institute of Mental Health (U.S.) (grant P50-MH58880)National Science Foundation (U.S.) (grant number 0543651)National Institute of Mental Health (U.S.) (grant number MH609197)National Institute of Mental Health (U.S.) (MH62122