Are venue-based strategies the ticket to the last mile in HIV prevention in Malawi

Background: In 2016, Blantyre District had the highest adult HIV prevalence in Malawi (17% overall; 22% in women) and the lowest viral suppression rate (60%). In response, the MOH expanded prevention and treatment strategies. We hypothesized that social venues patronized by people with high sexual partnerships rates could identify sub-groups currently missed. Methods: We conducted cross-sectional bio-behavioral surveys of representative samples of individuals seeking care in government clinics (n=2313) and social venue patrons (n=1802) Jan-Mar 2022. Clinics were randomly selected from government clinics providing HIV testing. Venues were randomly sampled from urban and rural strata with oversampling of rural venues. Sampling weights were based on 2-stage sampling probabilities. We followed national testing protocols for rapid tests, recency testing and viral load measurements. Acute infections were identified by pooling dried blood spots from persons with an HIV- rapid test. Results: Compared to the clinic population, the venue population was more likely to: be male (68% vs 28%); aged >25 years (61% vs 51%); unmarried (62% vs 40%); drink alcohol daily (43% vs 8%); have more sexual partners in the last year (mean 16 vs 2); report a new sex partner in the past 4 weeks (42% vs 14%); and report transactional sex (52% vs 12%). HIV prevalence (Table 1) was higher among the venue population (19% vs 9%); the proportion HIV+ suppressed was similar (78%). Among women recruited at venues, prevalence increased by age: 0% among age 15-17 to 41% among age 18-21. At venues, factors associated with HIV infection include female sex (39% vs 10%); having a new partner in the past 4 weeks (28% vs 13%) and transactional sex (25% vs 13%). Acute and recent infections were uncommon. Clinic participants who reported visiting venues were less likely to have a suppressed viral load than other PLHIV clinic participants (53% vs 81%). Among both populations, reporting a genital sore in the past 4 weeks was associated with non-suppression (40% vs 20% in clinic; 48% vs 20% in venues). Conclusions: Lower HIV prevalence and greater viral suppression suggests that Blantyre’s HIV epidemic is slowing. Strategies to further reduce transmission should include outreach to venues with higher prevalence of unsuppressed infection and to young women at venues. Testing for acute or recent infection yielded few cases and thus did not provide sufficient value to warrant the cost

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Use of antitussive medications in acute cough in young children

Acute cough, a common complaint in young children, is often the result of a viral upper respiratory infection. Cough and cold remedies generate billions of dollars in annual sales in the United States, despite a lack of evidence of their efficacy and multiple warnings by the US Food and Drug Administration. The current article begins with the best available evidence for common over-the-counter (OTC) and prescription antitussive remedies in children. The article concludes with a discussion of the pros and cons for the use of antitussives in children with cough. In general, OTC antitussive medications should not be routinely used in children under 2 years of age. In certain cases, antitussives with minimal adverse profile and some evidence of benefit may be recommended after informed counseling

Inter-species interconnections in acid mine drainage microbial communities

Metagenomic studies are revolutionizing our understanding of microbes in the biosphere. They have uncovered numerous proteins of unknown function in tens of essentially unstudied lineages that lack cultivated representatives. Notably, few of these microorganisms have been visualized, and even fewer have been described ultra-structurally in their essentially intact, physiologically relevant states. Here, we present cryogenic transmission electron microscope (cryo-TEM) 2D images and 3D tomographic datasets for archaeal species from natural acid mine drainage (AMD) microbial communities. Ultrastructural findings indicate the importance of microbial interconnectedness via a range of mechanisms, including direct cytoplasmic bridges and pervasive pili. The data also suggest a variety of biological structures associated with cell-cell interfaces that lack explanation. Some may play roles in inter-species interactions. Interdependences amongst the archaea may have confounded prior isolation efforts. Overall, the findings underline knowledge gaps related to archaeal cell components and highlight the likely importance of co-evolution in shaping microbial lineages

Structural and Morphological Characterization of Aggregated Species of α-Synuclein Induced by Docosahexaenoic Acid

The interaction of brain lipids with α-synuclein may play an important role in the pathogenesis of Parkinson disease (PD). Docosahexaenoic acid (DHA) is an abundant fatty acid of neuronal membranes, and it is presents at high levels in brain areas with α-synuclein inclusions of patients with PD. In animal models, an increase of DHA content in the brain induces α-synuclein oligomer formation in vivo. However, it is not clear whether these oligomeric species are the precursors of the larger aggregates found in Lewy bodies of post-mortem PD brains. To characterize these species and to define the role of fatty acids in amyloid formation, we investigated the aggregation process of α-synuclein in the presence of DHA. We found that DHA readily promotes α-synuclein aggregation and that the morphology of these aggregates is dependent on the ratio between the protein and DHA. In the presence of a molar ratio protein/DHA of 1:10, amyloid-like fibrils are formed. These fibrils are morphologically different from those formed by α-synuclein alone and have a less packed structure. At a protein/DHA molar ratio of 1:50, we observe the formation of stable oligomers. Moreover, chemical modifications, methionine oxidations, and protein-lipid adduct formations are induced by increasing concentrations of DHA. The extent of these modifications defines the structure and the stability of aggregates. We also show that α-synuclein oligomers are more toxic if generated in the presence of DHA in dopaminergic neuronal cell lines, suggesting that these species might be important in the neurodegenerative process associated with PD

Mode of Action of cGMP-dependent Protein Kinase-specific Inhibitors Probed by Photoaffinity Cross-linking Mass Spectrometry*

The inhibitor peptide DT-2 (YGRKKRRQRRRPPLRKKKKKH) is the most potent and selective inhibitor of the cGMP-dependent protein kinase (PKG) known today. DT-2 is a construct of a PKG tight binding sequence (W45, LRKKKKKH, KI = 0.8 μm) and a membrane translocating sequence (DT-6, YGRKKRRQRRRPP, KI = 1.1 μm), that combined strongly inhibits PKG catalyzed phosphorylation (KI = 12.5 nm) with ∼1000-fold selectivity toward PKG over protein kinase A, the closest relative of PKG. However, the molecular mechanism behind this inhibition is not entirely understood. Using a combination of photoaffinity labeling, stable isotope labeling, and mass spectrometry, we have located the binding sites of PKG-specific substrate and inhibitor peptides. Covalent linkage of a PKG-specific substrate analogue was localized in the catalytic core on residues 356–372, also known as the glycine-rich loop, essential for ATP binding. By analogy, the individual inhibitor peptides W45 and DT-6 were also found to cross-link near the glycine-rich loop, suggesting these are both substrate competitive inhibitors. A bifunctional photoreactive analogue of DT-2 was found to generate dimers of PKG. This cross-linking induced covalent PKG dimerization was not observed for an N-terminal deletion mutant of PKG, which lacks the dimerization domain. In addition, non-covalent mass spectrometry was used to determine binding stoichiometry and binding order of the inhibitor peptides. Dimeric PKG binds two W45 and DT-6 peptides, whereas only one DT-2 molecule was observed to bind to the dimeric PKG. Taken together, these findings imply that (i) the two individual components making up DT-2 are both targeted against the substrate-binding site and (ii) binding of a single DT-2 molecule inactivates both PKG monomers simultaneously, which is an indication that (iii) in cGMP-activated PKG the catalytic centers of both subunits may be in each other's proximity