86 research outputs found

    A long-acting formulation of the integrase inhibitor raltegravir protects humanized BLT mice from repeated high-dose vaginal HIV challenges

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    Pre-exposure prophylaxis (PrEP) using antiretroviral drugs (ARVs) has been shown to reduce HIV transmission in people at high risk of HIV infection. Adherence to PrEP strongly correlates with the level of HIV protection. Long-acting injectable ARVs provide sustained systemic drug exposures over many weeks and can improve adherence due to infrequent parenteral administration. Here, we evaluated a new long-acting formulation of raltegravir for prevention of vaginal HIV transmission

    A long-acting formulation of the integrase inhibitor raltegravir protects humanized BLT mice from repeated high-dose vaginal HIV challenges

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    Objectives: Pre-exposure prophylaxis (PrEP) using antiretroviral drugs (ARVs) has been shown to reduce HIV transmission in people at high risk of HIV infection. Adherence to PrEP strongly correlates with the level of HIV protection. Long-acting injectable ARVs provide sustained systemic drug exposures over many weeks and can improve adherence due to infrequent parenteral administration. Here, we evaluated a new long-acting formulation of raltegravir for prevention of vaginal HIV transmission. Methods: Long-acting raltegravir was administered subcutaneously to BALB/c, NSG (NOD -scid -gamma) and humanized BLT (bone marrow -liver -thymus) mice and rhesus macaques. Raltegravir concentration in peripheral blood and tissue was analysed. Suppression of HIV replication was assessed in infected BLT mice. Two high-dose HIV vaginal challenges were used to evaluate protection from HIV transmission in BLT mice. Results: Two weeks after a single subcutaneous injection of long-acting raltegravir in BLT mice (7.5 mg) and rhesus macaques (160 mg), the plasma concentration of raltegravir was comparable to 400 mg orally, twice daily in humans. Serum collected from mice 3 weeks post-administration of long-acting raltegravir efficiently blocked HIV infection of TZM-bl indicator cells in vitro. Administration of long-acting raltegravir suppressed viral RNA in plasma and cervico-vaginal fluids of infected BLT mice, demonstrating penetration of active raltegravir into the female reproductive tract. Using transmitted/founder HIV we observed that BLT mice administered a single subcutaneous dose of long-acting raltegravir were protected from two high-dose HIV vaginal challenges 1 week and 4 weeks after drug administration. Conclusions: These preclinical results demonstrated the efficacy of long-acting raltegravir in preventing vaginal HIV transmission

    CD32 is expressed on cells with transcriptionally active HIV but does not enrich for HIV DNA in resting T cells

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    The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and bore a TH2 phenotype as defined by CXCR3, CCR4, and CCR6. CD32 expression did not selectively enrich for HIV- or SIV-infected CD4+ T cells in peripheral blood or lymphoid tissue; isolated CD32+ resting CD4+ T cells accounted for less than 3% of the total HIV DNA in CD4+ T cells. Cell-associated HIV DNA and RNA loads in CD4+ T cells positively correlated with the frequency of CD32+ CD69+ CD4+ T cells but not with CD32 expression on resting CD4+ T cells. Using RNA fluorescence in situ hybridization, CD32 coexpression with HIV RNA or p24 was detected after in vitro HIV infection (peripheral blood mononuclear cell and tissue) and in vivo within lymph node tissue from HIV-infected individuals. Together, these results indicate that CD32 is not a marker of resting CD4+ T cells or of enriched HIV DNA–positive cells after ART; rather, CD32 is predominately expressed on a subset of activated CD4+ T cells enriched for transcriptionally active HIV after long-term ART

    Measuring nickel masses in Type Ia supernovae using cobalt emission in nebular phase spectra

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    The light curves of Type Ia supernovae (SNe Ia) are powered by the radioactive decay of 56^{56}Ni to 56^{56}Co at early times, and the decay of 56^{56}Co to 56^{56}Fe from ~60 days after explosion. We examine the evolution of the [Co III] 5892 A emission complex during the nebular phase for SNe Ia with multiple nebular spectra and show that the line flux follows the square of the mass of 56^{56}Co as a function of time. This result indicates both efficient local energy deposition from positrons produced in 56^{56}Co decay, and long-term stability of the ionization state of the nebula. We compile 77 nebular spectra of 25 SN Ia from the literature and present 17 new nebular spectra of 7 SNe Ia, including SN2014J. From these we measure the flux in the [Co III] 5892 A line and remove its well-behaved time dependence to infer the initial mass of 56^{56}Ni (MNiM_{Ni}) produced in the explosion. We then examine 56^{56}Ni yields for different SN Ia ejected masses (MejM_{ej} - calculated using the relation between light curve width and ejected mass) and find the 56^{56}Ni masses of SNe Ia fall into two regimes: for narrow light curves (low stretch s~0.7-0.9), MNiM_{Ni} is clustered near MNiM_{Ni} ~ 0.4M⊙M_\odot and shows a shallow increase as MejM_{ej} increases from ~1-1.4M⊙M_\odot; at high stretch, MejM_{ej} clusters at the Chandrasekhar mass (1.4M⊙M_\odot) while MNiM_{Ni} spans a broad range from 0.6-1.2M⊙M_\odot. This could constitute evidence for two distinct SN Ia explosion mechanisms.Comment: 16 pages, 12 figures (main text), plus data tables in appendix. Spectra released on WISeREP. Submitted to MNRAS, comments welcom

    In vivo analysis of the effect of panobinostat on cell-associated HIV RNA and DNA levels and latent HIV infection

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    Abstract Background The latent reservoir in resting CD4+ T cells presents a major barrier to HIV cure. Latency-reversing agents are therefore being developed with the ultimate goal of disrupting the latent state, resulting in induction of HIV expression and clearance of infected cells. Histone deacetylase inhibitors (HDACi) have received a significant amount of attention for their potential as latency-reversing agents. Results Here, we have investigated the in vitro and systemic in vivo effect of panobinostat, a clinically relevant HDACi, on HIV latency. We showed that panobinostat induces histone acetylation in human PBMCs. Further, we showed that panobinostat induced HIV RNA expression and allowed the outgrowth of replication-competent virus ex vivo from resting CD4+ T cells of HIV-infected patients on suppressive antiretroviral therapy (ART). Next, we demonstrated that panobinostat induced systemic histone acetylation in vivo in the tissues of BLT humanized mice. Finally, in HIV-infected, ART-suppressed BLT mice, we evaluated the effect of panobinostat on systemic cell-associated HIV RNA and DNA levels and the total frequency of latently infected resting CD4+ T cells. Our data indicate that panobinostat treatment resulted in systemic increases in cellular levels of histone acetylation, a key biomarker for in vivo activity. However, panobinostat did not affect the levels of cell-associated HIV RNA, HIV DNA, or latently infected resting CD4+ T cells. Conclusion We have demonstrated robust levels of systemic histone acetylation after panobinostat treatment of BLT humanized mice; and we did not observe a detectable change in the levels of cell-associated HIV RNA, HIV DNA, or latently infected resting CD4+ T cells in HIV-infected, ART-suppressed BLT mice. These results are consistent with the modest effects noted in vitro and suggest that combination therapies may be necessary to reverse latency and enable clearance. Animal models will contribute to the progress towards an HIV cure

    Healthcare professionals' perceptions of pain in infants at risk for neurological impairment

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    BACKGROUND: To determine whether healthcare professionals perceive the pain of infants differently due to their understanding of that infant's level of risk for neurological impairment. METHOD: Neonatal Intensive Care Units (NICU's) at two tertiary pediatric centers. Ninety-five healthcare professionals who practice in the NICU (50 nurses, 19 physicians, 17 respiratory therapists, 9 other) participated. They rated the pain (0–10 scale and 0–6 Faces Pain Scale), distress (0–10), effectiveness of cuddling to relieve pain (0–10) and time to calm without intervention (seconds) for nine video clips of neonates receiving a heel stick. Prior to each rating, they were provided with descriptions that suggested the infant had mild, moderate or severe risk for neurological impairment. Ratings were examined as a function of the level of risk described. RESULTS: Professionals' ratings of pain, distress, and time to calm did not vary significantly with level of risk, but ratings of the effectiveness of cuddling were significantly lower as risk increased [F (2,93) = 4.4, p = .02]. No differences in ratings were found due to participants' age, gender or site of study. Physicians' ratings were significantly lower than nurses' across ratings. CONCLUSION: Professionals provided with visual information regarding an infants' pain during a procedure did not display the belief that infants' level of risk for neurological impairment affected their pain experience. Professionals' estimates of the effectiveness of a nonpharmacological intervention did differ due to level of risk

    SN 2009ip at late times - an interacting transient at+2 years

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    We present photometric and spectroscopic observations of the interacting transient SN 2009ip taken during the 2013 and 2014 observing seasons. We characterize the photometric evolution as a steady and smooth decline in all bands, with a decline rate that is slower than expected for a solely Co-56-powered supernova at late phases. No further outbursts or eruptions were seen over a two year period from 2012 December until 2014 December. SN 2009ip remains brighter than its historic minimum from pre-discovery images. Spectroscopically, SN 2009ip continues to be dominated by strong, narrow (less than or similar to 2000 km s(-1)) emission lines of H, He, Ca, and Fe. While we make tenuous detections of [Fe II] lambda 7155 and [O I] lambda lambda 6300, 6364 lines at the end of 2013 June and the start of 2013 October, respectively, we see no strong broad nebular emission lines that could point to a core-collapse origin. In general, the lines appear relatively symmetric, with the exception of our final spectrum in 2014 May, when we observe the appearance of a redshifted shoulder of emission at +550 km s(-1). The lines are not blueshifted, and we see no significant near-or mid-infrared excess. From the spectroscopic and photometric evolution of SN 2009ip until 820 d after the start of the 2012a event, we still see no conclusive evidence for core-collapse, although whether any such signs could be masked by ongoing interaction is unclear

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Multi-omic profiling reveals the ataxia protein sacsin is required for integrin trafficking and synaptic organization

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    Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset cerebellar ataxia caused by mutations in SACS, which encodes the protein sacsin. Cellular ARSACS phenotypes include mitochondrial dysfunction, intermediate filament disorganization, and progressive death of cerebellar Purkinje neurons. It is unclear why the loss of sacsin causes these deficits or why they manifest as cerebellar ataxia. Here, we perform multi-omic profiling in sacsin knockout (KO) cells and identify alterations in microtubule dynamics and mislocalization of focal adhesion (FA) proteins, including multiple integrins. Deficits in FA structure, signaling, and function can be rescued by targeting PTEN, a negative regulator of FA signaling. ARSACS mice possess mislocalization of ITGA1 in Purkinje neurons and synaptic disorganization in the deep cerebellar nucleus (DCN). The sacsin interactome reveals that sacsin regulates interactions between cytoskeletal and synaptic adhesion proteins. Our findings suggest that disrupted trafficking of synaptic adhesion proteins is a causal molecular deficit in ARSACS

    Preliminary Acceptability of a Home-Based Peripheral Blood Collection Device for Viral Load Testing in the Context of Analytical Treatment Interruptions in HIV Cure Trials: Results from a Nationwide Survey in the United States

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    Frequent viral load testing is necessary during analytical treatment interruptions (ATIs) in HIV cure-directed clinical trials, though such may be burdensome and inconvenient to trial participants. We implemented a national, cross-sectional survey in the United States to examine the acceptability of a novel home-based peripheral blood collection device for HIV viral load testing. Between June and August 2021, we distributed an online survey to people with HIV (PWH) and community members, biomedical HIV cure researchers and HIV care providers. We performed descriptive analyses to summarize the results. We received 73 survey responses, with 51 from community members, 12 from biomedical HIV cure researchers and 10 from HIV care providers. Of those, 51 (70%) were cisgender men and 50 (68%) reported living with HIV. Most (>80% overall) indicated that the device would be helpful during ATI trials and they would feel comfortable using it themselves or recommending it to their patients/participants. Of the 50 PWH, 42 (84%) indicated they would use the device if they were participating in an ATI trial and 27 (54%) also expressed a willingness to use the device outside of HIV cure studies. Increasing sensitivity of viral load tests and pluri-potency of the device (CD4 count, chemistries) would augment acceptability. Survey findings provide evidence that viral load home testing would be an important adjunct to ongoing HIV cure-directed trials involving ATIs. Survey findings may help inform successful implementation and uptake of the device in the context of personalized HIV care
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