59 research outputs found

    Sexual behaviour change following HIV testing services: a systematic review and meta-analysis.

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    INTRODUCTION: Learning one's HIV status through HIV testing services (HTS) is an essential step toward accessing treatment and linking to preventive services for those at high HIV risk. HTS may impact subsequent sexual behaviour, but the degree to which this varies by population or is true in the setting of contemporary HIV prevention activities is largely unknown. As part of the 2019 World Health Organization Consolidated Guidelines on HTS, we undertook a systematic review and meta-analysis to determine the effect of HTS on sexual behaviour. METHODS: We searched nine electronic databases for studies published between July 2010 and December 2019. We included studies that reported on at least one outcome (condom use [defined as the frequency of condom use or condom-protected sex], number of sex partners, HIV incidence, STI incidence/prevalence). We included studies that prospectively assessed outcomes and that fit into one of three categories: (1) those evaluating more versus less-intensive HTS, (2) those of populations receiving HTS versus not and (3) those evaluating outcomes after versus before HTS. We conducted meta-analyses using random-effects models. RESULTS AND DISCUSSION: Of 29 980 studies screened, 76 studies were included. Thirty-eight studies were randomized controlled trials, 36 were cohort studies, one was quasi-experimental and one was a serial cross-sectional study. There was no significant difference in condom use among individuals receiving more-intensive HTS compared to less-intensive HTS (relative risk [RR]=1.03; 95% CI: 0.99 to 1.07). Condom use was significantly higher after receiving HTS compared to before HTS for individuals newly diagnosed with HIV (RR = 1.65; 95% CI: 1.36 to 1.99) and marginally significantly higher for individuals receiving an HIV-negative diagnosis (RR = 1.63; 95% CI: 1.01 to 2.62). Individuals receiving more-intensive HTS reported fewer sex partners at follow-up than those receiving less-intensive HTS, but the finding was not statistically significant (mean difference = -0.28; 95% CI: -3.66, 3.10). CONCLUSIONS: Our findings highlight the importance of using limited resources towards HTS strategies that focus on early HIV diagnosis, treatment and prevention services rather than resources dedicated to supplementing or enhancing HTS with additional counselling or other interventions

    Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study

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    Background Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country’s largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. Methods In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). Findings Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9·6 [95% CI 3·6 – 24]) and absence of an evening meal (2·2 [1·2–4·3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7·8 [95% CI 3·3–18·8], without evening meal; OR 3·6 [1·1–11·1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 μg/g to 152·0 μg/g and MCPG ranged from 44·9 μg/g to 220·0 μg/g. Interpretation Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks

    A Systematic Analysis of Cell Cycle Regulators in Yeast Reveals That Most Factors Act Independently of Cell Size to Control Initiation of Division

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    Upstream events that trigger initiation of cell division, at a point called START in yeast, determine the overall rates of cell proliferation. The identity and complete sequence of those events remain unknown. Previous studies relied mainly on cell size changes to identify systematically genes required for the timely completion of START. Here, we evaluated panels of non-essential single gene deletion strains for altered DNA content by flow cytometry. This analysis revealed that most gene deletions that altered cell cycle progression did not change cell size. Our results highlight a strong requirement for ribosomal biogenesis and protein synthesis for initiation of cell division. We also identified numerous factors that have not been previously implicated in cell cycle control mechanisms. We found that CBS, which catalyzes the synthesis of cystathionine from serine and homocysteine, advances START in two ways: by promoting cell growth, which requires CBS's catalytic activity, and by a separate function, which does not require CBS's catalytic activity. CBS defects cause disease in humans, and in animals CBS has vital, non-catalytic, unknown roles. Hence, our results may be relevant for human biology. Taken together, these findings significantly expand the range of factors required for the timely initiation of cell division. The systematic identification of non-essential regulators of cell division we describe will be a valuable resource for analysis of cell cycle progression in yeast and other organisms

    Capturing sequence diversity in metagenomes with comprehensive and scalable probe design.

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    Metagenomic sequencing has the potential to transform microbial detection and characterization, but new tools are needed to improve its sensitivity. Here we present CATCH, a computational method to enhance nucleic acid capture for enrichment of diverse microbial taxa. CATCH designs optimal probe sets, with a specified number of oligonucleotides, that achieve full coverage of, and scale well with, known sequence diversity. We focus on applying CATCH to capture viral genomes in complex metagenomic samples. We design, synthesize, and validate multiple probe sets, including one that targets the whole genomes of the 356 viral species known to infect humans. Capture with these probe sets enriches unique viral content on average 18-fold, allowing us to assemble genomes that could not be recovered without enrichment, and accurately preserves within-sample diversity. We also use these probe sets to recover genomes from the 2018 Lassa fever outbreak in Nigeria and to improve detection of uncharacterized viral infections in human and mosquito samples. The results demonstrate that CATCH enables more sensitive and cost-effective metagenomic sequencing

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Integrating epidemiologic and molecular methods to improve vaginal health

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    Thesis (Ph.D.)--University of Washington, 2022Challenges measuring the microbiome and limited incorporation of epidemiologic methods in microbiome science have hindered the progress of vaginal microbiome research, and major questions in the field remain unanswered despite decades of work. This dissertation seeks to address these gaps by describing measurement error and resulting bias in vaginal microbiota research; evaluating the state of epidemiologic evidence regarding the role of Lactobacillus iners, a controversial vaginal bacterial species, in various sexual health outcomes; and investigating bacterial drivers of BV symptomatology. The most popular method for characterizing the vaginal microbiota is 16S rRNA gene amplicon sequencing, which provides information on the taxonomic composition of a bacterial community. Shotgun metagenome sequencing characterizes the bacterial genes in a sample and provides information on the community’s functional potential, which is more relevant to understanding mechanisms and causal relationships between the microbiome and health outcomes than taxonomic composition. Metagenome inference methods attempt to bridge the gap between 16S rRNA gene amplicon sequencing and shotgun metagenomics by predicting a bacterial community’s metagenome based on its taxonomic composition and annotated whole genome sequences of its members. Several studies have compared metagenome inference performance in different human body sites; however, none specifically reported on the vaginal microbiome. In Chapter 2, we compared the performance of two popular metagenome inference methods, PICRUSt2 and Tax4Fun2, using paired 16S rRNA gene amplicon sequencing and shotgun metagenome sequencing data from vaginal samples from 72 pregnant individuals enrolled in the Pregnancy, Infection, and Nutrition cohort. PICRUSt2 and Tax4Fun2 performed modestly overall (median Spearman correlations between observed and predicted KEGG ortholog [KO] relative abundances 0.20 and 0.22, respectively). Both methods performed best among Lactobacillus crispatus-dominated vaginal microbiotas (median Spearman correlations 0.24 and 0.25, respectively) and worst among L. iners-dominated microbiotas (median Spearman correlations 0.06 and 0.11, respectively). Differential metagenome inference performance across vaginal microbiota community types can be considered differential measurement error, which often results in differential misclassification. As such, metagenome inference will introduce hard-to-predict bias in vaginal microbiome research. These findings demonstrate the importance of considering common epidemiologic biases in designing and evaluating novel microbiome analytic methods. The vaginal microbiota of reproductive-age individuals is often dominated by a single Lactobacillus species, most commonly L. iners or L. crispatus. While L. crispatus-dominated vaginal microbiotas are widely thought to protect against adverse sexual health outcomes, the role of L. iners-dominated microbiotas is less clear and has been debated. To better understand the role of L. iners, in Chapter 3 we conducted systematic reviews of the associations between L. iners compared to L. crispatus and the following outcomes: bacterial vaginosis (BV); Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, human papillomavirus (HPV), HIV, and genital herpes simplex virus type-2 (HSV-2) infections; and cervical dysplasia. We searched four databases for epidemiologic studies of reproductive-age, nonpregnant, cisgender women that used marker gene sequencing to characterize vaginal microbiota composition and presented an effect estimate for the association between L. iners compared to L. crispatus and outcomes of interest. For outcomes with >3 eligible studies presenting the same form of effect estimate, we conducted random-effects meta-analysis. Three BV studies were included in meta-analysis, which indicated L. iners-dominated microbiotas were associated with 2.1-fold higher prevalence of BV compared to L. crispatus-dominated microbiotas (95% CI 0.9-4.9). Six C. trachomatis studies were included in meta-analysis, which showed L. iners-dominated microbiotas were associated with 3.4-fold higher odds of chlamydia compared to L. crispatus-dominated microbiotas (95% CI 2.1-5.4). L. iners-dominated vaginal microbiotas may be suboptimal compared to L. crispatus-dominated microbiotas for BV and chlamydia, which is consistent with prior in vitro, in silico, and genomic work. Evidence was sparse for other outcomes. Nearly all included studies assessed microbiota composition and outcome status cross-sectionally and were at serious risk of bias, critically limiting the quality of evidence reviewed. In contrast to Lactobacillus-dominated microbiotas, BV is a polymicrobial condition characterized by a diverse community of anaerobic and facultative bacteria. It is the most common cause of vaginal discharge worldwide, affecting approximately one quarter of reproductive-age individuals. In high-resource settings, clinical BV diagnosis is typically based on the presence of at least three of four signs and symptoms termed Amsel criteria: amine odor on addition of potassium hydroxide to vaginal fluid; clue cells on vaginal wet prep; thin, gray, homogeneous vaginal discharge; and elevated vaginal pH. Because bacterial colonization and associations with these signs and symptoms may vary between populations, in Chapter 4 we assessed relationships between vaginal bacteria and Amsel criteria among two distinct populations. We included Kenyan participants from the placebo arm of the Preventing Vaginal Infections (PVI) trial and participants from a Seattle-based cross-sectional BV study in this analysis. Amsel criteria were recorded at study visits, and the vaginal microbiota was characterized using 16S rRNA gene amplicon sequencing. We fit logistic regression models to evaluate associations between bacterial relative abundance and each Amsel criterion. BV-associated bacterium 1 (BVAB1) was positively associated with all Amsel criteria in both populations. Eggerthella type 1, Fannyhessea (Atopobium) vaginae, Gardnerella spp., Sneathia amnii, and Sneathia sanguinegens were positively associated with all Amsel criteria in the Seattle study, and all but discharge in the PVI trial. This core group of vaginal bacteria may play a key role in the manifestation of BV signs and symptoms across diverse populations, and these findings are consistent with growing evidence regarding the role of biogenic amines and extracellular enzymes in BV etiology and symptom manifestation. Finally, in Chapter 5 I discuss the implications of this dissertation work for microbiome science, medicine, and public health. I recommend avenues by which investigators can better incorporate epidemiologic methods and principles into their work, I provide a novel characterization of L. iners, and I weigh various strategies to improve BV diagnostics and treatment in high- and low-resource settings

    Ruthenium Compounds for Photodynamic Chemotherapeutics and Solar Fuel Generation

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    Ruthenium polypyridyl complexes have long been studied due to their unique photophysical characteristics and their synthetic accessibility. We report here the use of new ruthenium polypyridyl’s in photodynamic chemotherapeutic and solar fuel applications. Nearly half of all chemotherapeutics administered today are derived from platinum-based drugs (platins) which lack specificity and can cause sever side-effects. Photodynamic chemotherapeutics (PDT) circumvent these issues utilizing light activation at the site of cancerous cells to generate a cytotoxic Ru(II) center and eventually trigger cellular apoptosis. The new PDT pro-drugs presented push their metal-to-ligand charge transfer (MLCT) light absorption out into the near-IR which is able to penetrate skin at greater depths than traditional PDT drugs. New Ru(II) hydrogen fuel evolution catalyst for use in dye-sensitized photoelectrosynthesis cells (DSPECs) based off of the extensively explored octahedral tridentate-bidentate coordination motif is also investigated. In particular, pendant bases are oriented toward the active site of the catalyst to increase catalytic rates and lower overpotentials. Preliminary density functional theory calculations show that strategic placement of the pendant amine on the bidentate ligand allows for productive interactions between the base and the active site of the catalyst to evolve hydrogen

    Core lipid, surface lipid and apolipoprotein composition analysis of lipoprotein particles as a function of particle size in one workflow integrating asymmetric flow field-flow fractionation and liquid chromatography-tandem mass spectrometry

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    <div><p>Lipoproteins are complex molecular assemblies that are key participants in the intricate cascade of extracellular lipid metabolism with important consequences in the formation of atherosclerotic lesions and the development of cardiovascular disease. Multiplexed mass spectrometry (MS) techniques have substantially improved the ability to characterize the composition of lipoproteins. However, these advanced MS techniques are limited by traditional pre-analytical fractionation techniques that compromise the structural integrity of lipoprotein particles during separation from serum or plasma. In this work, we applied a highly effective and gentle hydrodynamic size based fractionation technique, asymmetric flow field-flow fractionation (AF4), and integrated it into a comprehensive tandem mass spectrometry based workflow that was used for the measurement of apolipoproteins (apos A-I, A-II, A-IV, B, C-I, C-II, C-III and E), free cholesterol (FC), cholesterol esters (CE), triglycerides (TG), and phospholipids (PL) (phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and lysophosphatidylcholine (LPC)). Hydrodynamic size in each of 40 size fractions separated by AF4 was measured by dynamic light scattering. Measuring all major lipids and apolipoproteins in each size fraction and in the whole serum, using total of 0.1 ml, allowed the volumetric calculation of lipoprotein particle numbers and expression of composition in molar analyte per particle number ratios. Measurements in 110 serum samples showed substantive differences between size fractions of HDL and LDL. Lipoprotein composition within size fractions was expressed in molar ratios of analytes (A-I/A-II, C-II/C-I, C-II/C-III. E/C-III, FC/PL, SM/PL, PE/PL, and PI/PL), showing differences in sample categories with combinations of normal and high levels of Total-C and/or Total-TG. The agreement with previous studies indirectly validates the AF4-LC-MS/MS approach and demonstrates the potential of this workflow for characterization of lipoprotein composition in clinical studies using small volumes of archived frozen samples.</p></div
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