Genetic structure of the high dispersal Atlanto-Mediterreanean sea star Astropecten aranciacus revealed by mitochondrial DNA sequences and microsatellite loci

To investigate the impact of potential marine barriers on gene-flow in high dispersal marine invertebrates, we assessed the population genetic structure of the sea star Astropecten aranciacus. Samples were obtained from nine locations within the Atlantic and the Mediterranean Sea including populations east of the Siculo-Tunisian Strait. We obtained both DNA sequence data of the mitochondrial control region and genotype data at four microsatellite loci. Both markers were highly polymorphic and showed a great level of genetic diversity. Genetic differentiation between populations (F ST) was in general low, particularly for nuclear data, as is often the case in high dispersal marine invertebrates. Nevertheless, both marker sets indicated a significant genetic differentiation of the population from the island of Madeira to most other populations. Our results also demonstrate a clear pattern of isolation-by-distance supported by both mitochondrial and nuclear markers. Therefore, we conclude that larval dispersal of A. aranciacus is somewhat limited even within the basins of the Atlantic, the west Mediterranean and the east Mediterranean. Microsatellite loci further revealed genetic differentiation between the three basins; however, it is not clear whether this is truly caused by marine barriers. Genetic differentiation between basins might also be a result of isolation-by-distance allowing for any grouping to be significant as long as geographical neighbors are clustered together. Although levels of genetic differentiation were less pronounced in microsatellite data, both datasets were coherent and revealed similar patterns of genetic structure in A. aranciacu

Correlates of Delayed Diagnosis among Human Immunodeficiency Virus-Infected Pulmonary Tuberculosis Suspects in a Rural HIV Clinic, South Africa

Delay in pulmonary tuberculosis (PTB) diagnosis is one of the major factors that affect outcome and threatens continued spread of tuberculosis. This study aimed at determining factors associated with delayed PTB diagnosis among human immunodeficiency virus (HIV) infected individuals. Methods. A retrospective observational study was done using clinic records of HIV-infected PTB suspects attending an HIV/AIDS clinic at Tintswalo rural hospital in South Africa (SA) between January 2006 and December 2007. Using routine clinic registers, 480 records were identified. Results. PTB diagnosis delay was found among 77/176 (43.8%) of the patients diagnosed with PTB. The mean delay of PTB diagnosis was 170.6 days; diagnosis delay ranged 1–30 days in 27 (35.1%) patients, 31–180 days in 24 (33.8%) patients; 24 (31.2%) patients remained undiagnosed for ≥180 days. Independent factors associated with delayed diagnosis were: older age >40 years (Odds Ratio (OR) 3.43, 95% CI 1.45–8.08) and virological failure (OR 2.72, 95% CI 1.09–6.74). Conclusion. There is a considerable delayed PTB diagnosis among HIV-infected patients in rural SA. Older patients as well as patients with high viral load are at a higher risk of PTB diagnosis delay. Therefore efforts to reduce PTB diagnosis delay need to emphasised

Caspase-3-independent photoreceptor degeneration by N-methyl-N-nitrosourea (MNU) induces morphological and functional changes in the mouse retina

Background: Retinal degeneration is followed by significant changes in the structure and function of photoreceptors in humans and several genetic animal models. However, it is not clear whether similar changes occur when the degeneration is induced pharmacologically. Therefore, our aim was to investigate the influence of retinotoxic N-methyl-N-nitrosourea (MNU) on the function, morphology and underlying molecular pathways of programmed cell death. Methods: C57/BL6 mice were injected with different doses of MNU, and function was determined by analysing optokinetic reflex measurements and cued water maze results at several time points post-injection. Morphometric measurements were also taken from H&E-stained paraffin eye sections. TUNEL-positive cells and caspase-3 and -6 were detected by immunohistochemistry. To assess the molecular changes leading to cell death, qRT-PCR from neurosensory retina mRNA was performed. Results: The application of MNU led to an instant decrease in function and a delayed decrease in the thickness of the retinal outer nuclear layer. These responses were observed in the absence of any structural changes in the retinal pigment epithelium. The degeneration of the photoreceptor cell layer was highest with 60mg/kg MNU. The assessment of TUNEL-positive cells visualised cell death after treatment, but no detectable caspase-3 activity was observed concomitant with these changes. qRT-PCR revealed the possible involvement of the inflammatory mediator caspase-1 and endoplasmic reticulum stress-mediated apoptosis by caspase-12. Conclusion: MNU leads to the dose-dependent degeneration of photoreceptor cells in mice by caspase-3-independent pathways and is, therefore, a suitable model to study retinal degeneration in an animal mode

The size, characteristics and partnership networks of the health-related non-profit sector in three regions of South Africa: implications of changing primary health care policy for community-based care

Web of Scienc

"She is my teacher and if it was not for her I would be dead": Exploration of rural South African community health workers' information, education and communication activities

Community health workers (CHWs) are important resources in health systems affected by the HIV/AIDS pandemic. International guidelines on task-shifting recommend that CHWs can provide diverse HIV services, ranging from HIV prevention to counselling patients for lifelong antiretroviral therapy. There is, however, little evidence on the experiences with CHW delivery of these services in Africa. This qualitative study included 102 interviews that explored experiences with information, education and communication (IEC) activities provided by CHWs within rural South Africa. Semi- structured interviews were conducted with CHWs (n = 17), their clients (n = 33) and the primary caregivers of these clients (n = 30), allowing for data source triangulation. Twenty-two follow-up interviews explored emergent themes from preliminary interviews. Despite limited formal education and training, CHWs in this study were significant providers of IEC, including provision of generic health talks and HIV-specific information and facilitation to support clients’ entry and maintenance in the formal health system. They often incorporated local knowledge and understanding of illness in their communication. CHWs in this study were able to bridge the lifeworlds of the community and the formal services to expedite access and adherence to local clinics and other services. As mediators between the two worlds, CHWs reinterpreted health information to make it comprehensible in their communities. With growing formalisation of CHW programmes in South Africa and elsewhere, CHWs’ important role in health service access, health promotion and health maintenance must be recognised and supported in order to maximise impact.Web of Scienc

Evaluation of the Interaction Between TGF β and Nitric Oxide in the Mechanisms of Progression of Colon Carcinoma

It is recognised that stromal cells determine cancer progression. We have previously shown that active TGFβ produced by rat colon carcinoma cells modulated NO production in rat endothelial cells. To elucidate the role of TGFβ and NO in the mechanisms of interaction of colon carcinoma cells with stromal cells and in cancer progression, we transfected REGb cells, a regressive colon carcinoma clone secreting latent TGFβ, with a cDNA encoding for a constitutively-secreted active TGFβ. Out of 20 injected rats only one tumour progressed, which was resected and sub-cultured (ReBeta cells). ReBeta cells secreted high levels of active TGFβ. The adhesive properties of REGb and Rebeta cells to endothelial cells were similar, showing that the secretion of active TGFβ is not involved in tumour cell adhesion to endothelial cells. ReBeta, but not REGb, cell culture supernatants inhibited cytokine-dependent NO secretion by endothelial cells, but inhibition of NO production was similar in co-cultures of REGb or ReBeta cells with endothelial cells. Therefore, secretion of active TGFβ regulated endothelial NO synthase activity when tumour cells were distant from, but not in direct contact with, endothelial cells. However, only ReBeta cells inhibited cytokine-dependent secretion of NO in coculture with macrophages, indicating that the active-TGFβ-NO axis confers an advantage for tumour cells in their interaction with macrophages rather than endothelial cells in cancer progressio

Within and Between Subject Spectral Fingerprints of EEG-Microstate Parameters.

Early reports have claimed that EEG microstate features (e.g. their mean duration or percent of time covered) are largely independent from EEG spectra. This has meanwhile been questioned for conceptual and empirical reasons, but so far, EEG spectral power map correlates of microstate features have not been reported. We present the results of such analyses, conducted both within and between subjects, and report patterns of systematic changes in local EEG spectral amplitude associated with the mean duration, frequency of occurrence and relative contribution of particular microstate classes. The combination of EEG microstate analysis with spectral analysis may therefore be helpful to come to a deeper understanding of local patterns of activation and inhibition associated with particular microstate classes