Publications by authors named "Louis R Barrows"

(Mtb) remains a global human health threat and a significant cause of human morbidity and mortality. We document here the capture of Mtb transcripts in libraries designed to amplify eukaryotic mRNA. These reads are often considered spurious or nuisance and are rarely investigated.

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We successfully employed a single cell RNA sequencing (scRNA-seq) approach to describe the cells and the communication networks characterizing granulomatous lymph nodes of TB patients. When mapping cells from individual patient samples, clustered based on their transcriptome similarities, we uniformly identify several cell types that known to characterize human and non-human primate granulomas. Whether high or low Mtb burden, we find the T cell cluster to be one of the most abundant.

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Bacterial resistance to antibiotics is a crisis. is among the CDC urgent threat pathogens in part for this reason. Lipopeptides known as turnercyclamycins are produced by symbiotic bacteria that normally live in marine mollusks, where they may be involved in shaping their symbiotic niche.

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Bioactive compounds from medicinal plants are good alternative treatments for T2DM. They are also sources of lead molecules that could lead to new drug discoveries. In this study, Craib.

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HIV-1 cDNA pre-integration complexes persist for weeks in macrophages and remain transcriptionally active. While previous work has focused on the transcription of HIV-1 genes; our understanding of the cellular milieu that accompanies viral production is incomplete. We have used an system to model HIV-1 infection of macrophages, and single-cell RNA sequencing (scRNA-seq) to compare the transcriptomes of uninfected cells, cells harboring pre-integration complexes (PIC), and those containing integrated provirus and making late HIV proteins.

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Latency reversing agents (LRAs), such as protein kinase C (PKC) agonists, constitute a promising strategy for exposing and eliminating the HIV-1 latent reservoir. PKC agonists activate NF-κB and induce deleterious pro-inflammatory cytokine production. Adjuvant pharmacological agents, such as ruxolitinib, a JAK inhibitor, have previously been combined with LRAs to reduce deleterious pro-inflammatory cytokine secretion without inhibiting HIV-1 reactivation in vitro.

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Teredinibacter turnerae is an intracellular bacterial symbiont in the gills of wood-eating shipworms, where it is proposed to use antibiotics to defend itself and its animal host. Several biosynthetic gene clusters are conserved in T. turnerae and their host shipworms around the world, implying that they encode defensive compounds.

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Antimicrobial resistance is a growing global health and economic concern. Current antimicrobial agents are becoming less effective against common bacterial infections. We previously identified pyrrolocins A and C, which showed activity against a variety of Gram-positive bacteria.

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In search of new anti-tuberculars compatible with anti-retroviral therapy we re-identified amicetin as a lead compound. Amicetin's binding to the 70S ribosomal subunit of Thermus thermophilus (Tth) has been unambiguously determined by crystallography and reveals it to occupy the peptidyl transferase center P-site of the ribosome. The amicetin binding site overlaps significantly with that of the well-known protein synthesis inhibitor balsticidin S.

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Chemistry drives many biological interactions between the microbiota and host animals, yet it is often challenging to identify the chemicals involved. This poses a problem, as such small molecules are excellent sources of potential pharmaceuticals, pretested by nature for animal compatibility. We discovered anti-HIV compounds from small, marine tunicates from the Eastern Fields of Papua New Guinea.

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Following proviral integration into the host cell genome and establishment of a latent state, the human immunodeficiency virus type 1 (HIV-1) can reenter a productive life cycle in response to various stimuli. HIV-1 reactivation occurs when transcription factors, such as nuclear factor-κB (NF-κB), nuclear factor of activated T cells (NFAT), and activator protein -1 (AP-1), bind cognate sites within the long terminal repeat (LTR) region of the HIV-1 provirus to promote transcription. Interestingly, pattern recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) can reactivate latent HIV-1 through activation of the transcription factor NF-κB.

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The extract of a sample of the tunicate Didemnum molle (MAY13-117) collected in Mayotte afforded eight new metabolites, mollecarbamates A-D (1-4) and molleureas B-E (5-8), along with the two known natural products, N,N'-diphenylethyl urea (10) and molleurea A (11). Another sample of D. molle (MAD11-BA065) collected in Baie des Assassins, Madagascar, afforded molledihydroisoquinolone (9).

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The hypothesis underlying this current work is that fresh juice expressed from Papua New Guinea (PNG) medicinal plants (succus) will inhibit human Cytochrome P450s (CYPs). The CYP inhibitory activity identified in fresh material was compared with inhibition in methanol extracts of dried material. Succus is the most common method of traditional medicine (TM) preparation for consumption in PNG.

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Background: Rapid modernization in the East Sepik (ES) Province of Papua New Guinea (PNG) is resulting in a decrease in individuals knowledgeable in medicinal plant use. Here we report a synthesis and comparison of traditional medicinal plant use from four ethnically distinct locations in the ES Province and furthermore compare them to two other previous reports of traditional plant use from different provinces of PNG.

Methods: This manuscript is based on an annotated combination of four Traditional Medicines (TM) survey reports generated by University of Papua New Guinea (UPNG) trainees.

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A cascade silver(I)-catalyzed hydroamination/Michael addition sequence has been developed to deliver highly substituted bicyclic guanidines. This transformation gives rise to geometrically and constitutionally stable ene-guanidines and generates a remote stereocenter with moderate to high diastereoselectivity.

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Three new decalin-type tetramic acid analogues, pyrrolocins A (1), B (2), and C (3), were defined as products of a metabolic pathway from a fern endophyte, NRRL 50135, from Papua New Guinea. NRRL 50135 initially produced 1 but ceased its production before chemical or biological evaluation could be completed. Upon transfer of the biosynthetic pathway to a model host, 1-3 were produced.

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Strategies are needed for the robust production of cryptic, silenced, or engineered secondary metabolites in fungi. The filamentous fungus Fusarium heterosporum natively synthesizes the polyketide equisetin at >2 g L(-1) in a controllable manner. We hypothesized that this production level was achieved by regulatory elements in the equisetin pathway, leading to the prediction that the same regulatory elements would be useful in producing other secondary metabolites.

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A racemic, prenylated polyketide dimer, oxazinin A (1), was isolated from a novel filamentous fungus in the class Eurotiomycetes, and its structure was elucidated spectroscopically. The pentacyclic structure of oxazinin A (1) is a unique combination of benzoxazine, isoquinoline, and a pyran ring. Oxazinin A (1) exhibited antimycobacterial activity and modestly antagonized transient receptor potential (TRP) channels.

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Ascidians contain abundant, diverse secondary metabolites, which are thought to serve a defensive role and which have been applied to drug discovery. It is known that bacteria in symbiosis with ascidians produce several of these metabolites, but very little is known about factors governing these 'chemical symbioses'. To examine this phenomenon across a wide geographical and species scale, we performed bacterial and chemical analyses of 32 different ascidians, mostly from the didemnid family from Florida, Southern California and a broad expanse of the tropical Pacific Ocean.

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Ethnopharmacological Relevance: A substantial proportion of the population in Papua New Guinea (PNG) lives with human immunodeficiency virus (HIV). Treatment requires lifelong use of antiretroviral therapy (ART). The majority of people in PNG use traditional medicines (TM) derived from plants for all types of health promotions.

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Article Synopsis
  • * Waltheriones A and C demonstrated noteworthy anti-HIV effects in lab tests, effectively protecting cells at certain concentrations and inhibiting HIV P24 formation by over 50%.
  • * The structures of the identified alkaloids were confirmed using spectroscopic data analysis.
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An antimalarial screen for plants collected from Papua New Guinea identified an extract of Horsfieldia spicata as having activity. Isolation of the active constituents led to the identification of two new compounds: myristicyclins A (1) and B (2). Both compounds are procyanidin-like congeners of myristinins lacking a pendant aromatic ring.

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A novel lumun-lumun sampling methodology was used to obtain a large diversity of micromollusks, including the new species Lienardia totopotens. In turn, from L. totopotens we cultivated a Streptomyces sp.

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By means of bioassay-guided fractionation, a new steroidal alkaloid, plakinamine M (1), and the known compound, plakinamine L (2), with a unique acyclic side chain, were isolated from the marine sponge Corticium sp. collected from New Britain, Papua New Guinea. The structures were determined on the basis of extensive 1D and 2D NMR and HRESIMS.

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