Treatment Experience and Repeat Pregnancy Impact the Effectiveness of Non-Nucleoside Reverse Transcription Inhibitor-Highly Active Antiretroviral Therapy for the Prevention of Mother to Child Transmission of Human Immunodeficiency Virus.

Non-nucleoside reverse transcription inhibitor (NNRTI)-containing antiretroviral therapy (ART) for the prevention of mother to child transmission (PMTCT) of human immunodeficiency virus (HIV) has led to dramatic reductions in perinatal HIV infection in resource-constrained settings. Nonetheless, PMTCT programs are complicated by repeat pregnancies, in which long-term or repeat exposures to PMTCT regimens over time may lead to the acquisition of HIV drug resistance mutations, and consequent treatment failure. In this study, we retrospectively assessed the effectiveness of the NNRTI-based PMTCT protocol from 2008 to 2010 in The Bahamas National HIV/AIDS Program. We show that women who had been in repeat pregnancies and those who were already prescribed ART at conception were at increased risk of virologic failure, relative to treatment-inexperienced women and primigravida, respectively (AOR 3.1, 95% CI: 1.3-7.1, p = .008 and AOR 5.0, 95% CI: 1.8-14.1, p = .002). In addition, women undergoing treatment at conception were more likely to possess HIVDR mutations relative to treatment-naive women (AOR 447.1, 95% CI: 17.9-11,173.5, p = .001). Therefore, individual treatment history is a key metric determining the effectiveness of current and future PMTCT interventions. The implications of this to PMTCT programmatic success in light of the most recent WHO guidelines are discussed.

Performance of and preference for oral rapid HIV testing in The Bahamas.

Initiatives to increase access to quality rapid HIV diagnostics have had relative success in the Caribbean in recent years, including use of oral rapid HIV testing. However, to date, there has not been any investigation into the performance or acceptability of oral fluids HIV testing in the region. In this cross-sectional study in The Bahamas, 252 persons of unknown serostatus were tested side-by-side with two oral rapid test brands, and the results were compared with the national fingerprick algorithm. In addition, an exit survey was administered to 234 study participants to assess user test preference. The most frequent survey response was to have no test preference (47.8%), but of those who expressed a test preference, most preferred oral (34.4%) versus fingerprick (17.8%) method. Both OraQuick and AWARE were 100% concordant with the gold standard. Therefore, our results show that oral fluids rapid testing is preferred over fingerprick testing by a subset of the potential target population and performs well in a population of undiagnosed persons attending screening clinic in The Bahamas.

F3/contactin and TAG1 play antagonistic roles in the regulation of sonic hedgehog-induced cerebellar granule neuron progenitor proliferation.

Modulation of the sonic hedgehog (SHH) pathway is a crucial factor in cerebellar morphogenesis. Stimulation of granule neuron progenitor (GNP) proliferation is a central function of SHH signalling, but how this is controlled locally is not understood. We show that two sequentially expressed members of the contactin (CNTN) family of adhesion molecules, TAG1 and F3, act antagonistically to control SHH-induced proliferation: F3 suppresses SHH-induced GNP proliferation and induces differentiation, whereas TAG1 antagonises F3. Production of GNPs in TAG1-null mice is delayed and reduced. F3 and TAG1 colocalise on GNPs with the related L1-like adhesion molecule NrCAM, and F3 fails to suppress the SHH-induced proliferation of NrCAM-deficient GNPs. We show that F3 and SHH both primarily affect a group of intermediate GNPs (IPs), which, though actively dividing, also express molecules associated with differentiation, including ß-tubulin III (TuJ1) and TAG1. In vivo, intermediate progenitors form a discrete layer in the middle of the external germinal layer (mEGL), while F3 becomes expressed on the axons of postmitotic granule neurons as they leave the inner EGL (iEGL). We propose, therefore, that F3 acts as a localised signal in the iEGL that induces SHH-stimulated cells in the overlying mEGL to exit cell cycle and differentiate. By contrast, expression of TAG1 on GNPs antagonises this signal in the mEGL, preventing premature differentiation and sustaining GNP expansion in a paracrine fashion. Together, these findings indicate that CNTN and L1-like proteins play a significant role in modulating SHH-induced neuronal precursor proliferation.