Vaginal bacterial communities dominated by Lactobacillus species are associated with a reduced risk of various adverse health outcomes. However, somewhat unexpectedly, many healthy women have ...microbiota that are not dominated by lactobacilli. To determine the factors that drive vaginal community composition we characterized the genetic composition and transcriptional activities of vaginal microbiota in healthy women.
We demonstrate that the abundance of a species is not always indicative of its transcriptional activity and that impending changes in community composition can be predicted from metatranscriptomic data. Functional comparisons highlight differences in the metabolic activities of these communities, notably in their degradation of host produced mucin but not glycogen. Degradation of mucin by communities not dominated by Lactobacillus may play a role in their association with adverse health outcomes. Finally, we show that the transcriptional activities of L. crispatus, L. iners, and Gardnerella vaginalis vary with the taxonomic composition of the communities in which they reside. Notably, L. iners and G. vaginalis both demonstrate lower expression of their cholesterol-dependent cytolysins when co-resident with Lactobacillus spp. and higher expression when co-resident with other facultative and obligate anaerobes. The pathogenic potential of these species may depend on the communities in which they reside and thus could be modulated by interventional strategies.
Our results provide insight to the functional ecology of the vaginal microbiota, demonstrate the diagnostic potential of metatranscriptomic data, and reveal strategies for the management of these ecosystems.
Summary Background The Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) trial showed that apixaban is better than warfarin at prevention of stroke ...or systemic embolism, causes less bleeding, and results in lower mortality. We assessed in this trial's participants how results differed according to patients' CHADS2 , CHA2 DS2 VASc, and HAS-BLED scores, used to predict the risk of stroke and bleeding. Methods ARISTOTLE was a double-blind, randomised trial that enrolled 18 201 patients with atrial fibrillation in 39 countries. Patients were randomly assigned apixaban 5 mg twice daily (n=9120) or warfarin (target international normalised ratio 2·0–3·0; n=9081). The primary endpoint was stroke or systemic embolism. The primary safety outcome was major bleeding. We calculated CHADS2 , CHA2 DS2 VASc, and HAS-BLED scores of patients at randomisation. Efficacy analyses were by intention to treat, and safety analyses were of the population who received the study drug. ARISTOTLE is registered with ClinicalTrials.gov , number NCT00412984. Findings Apixaban significantly reduced stroke or systemic embolism with no evidence of a differential effect by risk of stroke (CHADS2 1, 2, or ≥3, p for interaction=0·4457; or CHA2 DS2 VASc 1, 2, or ≥3, p for interaction=0·1210) or bleeding (HAS-BLED 0–1, 2, or ≥3, p for interaction=0·9422). Patients who received apixaban had lower rates of major bleeding than did those who received warfarin, with no difference across all score categories (CHADS2 , p for interaction=0·4018; CHA2 DS2 VASc, p for interaction=0·2059; HAS-BLED, p for interaction=0·7127). The relative risk reduction in intracranial bleeding tended to be greater in patients with HAS-BLED scores of 3 or higher (hazard ratio HR 0·22, 95% CI 0·10–0·48) than in those with HAS-BLED scores of 0–1 (HR 0·66, 0·39–1·12; p for interaction=0·0604). Interpretation Because apixaban has benefits over warfarin that are consistent across patient risk of stroke and bleeding as assessed by the CHADS2 , CHA2 DS2 VASc, and HAS-BLED scores, these scores might be less relevant when used to tailor apixaban treatment to individual patients than they are for warfarin. Further improvement in risk stratification for both stroke and bleeding is needed, particularly for patients with atrial fibrillation at low risk for these events. Funding Bristol-Myers Squibb and Pfizer.
An ability to readily determine an anticoagulant effect with an emerging class of direct, active site, oral factor Xa inhibitors is viewed by the medical community as attractive and by some as an ...absolute requirement for their use in clinical practice. We performed a pharmacokinetic and pharmacodynamic substudy in APPRAISE-1—a study of apixaban in patients with acute coronary syndrome(ACS). A total of 1691 patients had blood sampled for apixaban plasma concentrations using mass spectrometry/high performance liquid chromatography and anti-Xa activity using a chromogenic assay employing either low molecular weight heparin or apixaban as reference standards. Anti-Xa activity, determined by either anti-Xa-LMWH (
r
= 0.9671;
P
< 0.0001) or anti-Xa-apixaban (
r
= 0.9669;
P
< 0.0001) correlated strongly and in a linear fashion with apixaban plasma concentrations. The correlations for each method were equally strong at low (<100 ng/ml) (
r
= 0.86,
P
< 0.0001;
r
= 0.85,
P
< 0.0001), intermediate(100–200 ng/ml) (
r
= 0.73,
P
< 0.0001;
r
= 0.69,
P
< 0.0001) and high (>200 ng/ml) (
r
= 0.91,
P
< 0.0001;
r
= 0.91,
P
< 0.0001) plasma concentrations of apixaban, respectively. Our pharmacokinetic and pharmacodynamic substudy suggests that an apixaban-mediated anticoagulant effect can be detected even at very low plasma concentrations using a standard laboratory chromogenic anti-Xa assay with either LMWH or apixaban calibrators. While establishing parameters for safety and efficacy will require further investigation, an ability to discern the presence of a drug effect may provide clinically useful information.
Amplification, sequencing, and analysis of the 16S rRNA gene affords characterization of microbial community composition. As this tool has become more popular and amplicon-sequencing applications ...have grown in the total number of samples, growth in sample multiplexing is becoming necessary while maintaining high sequence quality and sequencing depth. Here, modifications to the Illumina HiSeq 2500 platform are described which produce greater multiplexing capabilities and 300-bp paired-end reads of higher quality than those produced by the current Illumina MiSeq platform. To improve the feasibility and flexibility of this method, a 2-step PCR amplification protocol is also described that allows for targeting of different amplicon regions, and enhances amplification success from samples with low bacterial bioburden.
Amplicon sequencing has become a popular and widespread tool for surveying microbial communities. Lower overall costs associated with high-throughput sequencing have made it a widely adopted approach, especially for projects that necessitate sample multiplexing to eliminate batch effect and reduced time to acquire data. The method for amplicon sequencing on the Illumina HiSeq 2500 platform described here provides improved multiplexing capabilities while simultaneously producing greater quality sequence data and lower per-sample cost relative to those of the Illumina MiSeq platform without sacrificing amplicon length. To make this method more flexible for various amplicon-targeted regions as well as improve amplification from low-biomass samples, we also present and validate a 2-step PCR library preparation method.
"Leaky gut," or high intestinal barrier permeability, is common in preterm newborns. The role of the microbiota in this process remains largely uncharacterized. We employed both short- and long-read ...sequencing of the 16S rRNA gene and metagenomes to characterize the intestinal microbiome of a longitudinal cohort of 113 preterm infants born between 24
and 32
weeks of gestation. Enabled by enhanced taxonomic resolution, we found that a significantly increased abundance of Bifidobacterium breve and a diet rich in mother's breastmilk were associated with intestinal barrier maturation during the first week of life. We combined these factors using genome-resolved metagenomics and identified a highly specialized genetic capability of the
strains to assimilate human milk oligosaccharides and host-derived glycoproteins. Our study proposes mechanistic roles of breastmilk feeding and intestinal microbial colonization in postnatal intestinal barrier maturation; these observations are critical toward advancing therapeutics to prevent and treat hyperpermeable gut-associated conditions, including necrotizing enterocolitis (NEC).
Despite improvements in neonatal intensive care, necrotizing enterocolitis (NEC) remains a leading cause of morbidity and mortality. "Leaky gut," or intestinal barrier immaturity with elevated intestinal permeability, is the proximate cause of susceptibility to NEC. Early detection and intervention to prevent leaky gut in "at-risk" preterm neonates are critical for decreasing the risk of potentially life-threatening complications like NEC. However, the complex interactions between the developing gut microbial community, nutrition, and intestinal barrier function remain largely uncharacterized. In this study, we reveal the critical role of a sufficient breastmilk feeding volume and the specialized carbohydrate metabolism capability of
in the coordinated postnatal improvement of the intestinal barrier. Determining the clinical and microbial biomarkers that drive the intestinal developmental disparity will inform early detection and novel therapeutic strategies to promote appropriate intestinal barrier maturation and prevent NEC and other adverse health conditions in preterm infants.
The effect of storage conditions on the microbiome and metabolite composition of human biological samples has not been thoroughly investigated as a potential source of bias. We evaluated the effect ...of two common storage conditions used in clinical trials on the bacterial and metabolite composition of the vaginal microbiota using pyrosequencing of barcoded 16S rRNA gene sequencing and (1)H-NMR analyses.
Eight women were enrolled and four mid-vaginal swabs were collected by a physician from each woman. The samples were either processed immediately, stored at -80°C for 4 weeks or at -20°C for 1 week followed by transfer to -80°C for another 4 weeks prior to analysis. Statistical methods, including Kolmogorovo-Smirnov and Wilcoxon tests, were performed to evaluate the differences in vaginal bacterial community composition and metabolites between samples stored under different conditions. The results showed that there were no significant differences between samples processed immediately after collection or stored for varying durations. (1)H-NMR analysis of the small molecule metabolites in vaginal secretions indicated that high levels of lactic acid were associated with Lactobacillus-dominated communities. Relative abundance of lactic acid did not appear to correlate with relative abundance of individual Lactobacillus sp. in this limited sample, although lower levels of lactic acid were observed when L. gasseri was dominant, indicating differences in metabolic output of seemingly similar communities.
These findings benefit large-scale, field-based microbiome and metabolomic studies of the vaginal microbiota.
Introduction Clinician implicit racial bias (IB) may lead to lower quality care and adverse health outcomes for Black patients. Educational efforts to train clinicians to mitigate IB vary widely and ...have insufficient evidence of impact. We developed and pilot-tested an evidence-based clinician IB curriculum, “REACHing Equity.” Methods To assess acceptability and feasibility, we conducted an uncontrolled one-arm pilot trial with post-intervention assessments. REACHing Equity is designed for clinicians to: (1) acquire knowledge about IB and its impact on healthcare, (2) increase awareness of one's own capacity for IB, and (3) develop skills to mitigate IB in the clinical encounter. We delivered REACHing Equity virtually in three facilitated, interactive sessions over 7–9 weeks. Participants were health care providers who completed baseline and end-of-study evaluation surveys. Results Of approximately 1,592 clinicians invited, 37 participated, of whom 29 self-identified as women and 24 as non-Hispanic White. Attendance averaged 90% per session; 78% attended all 3 sessions. Response rate for evaluation surveys was 67%. Most respondents agreed or strongly agreed that the curriculum objectives were met, and that REACHing Equity equipped them to mitigate the impact of implicit bias in clinical care. Participants consistently reported higher self-efficacy for mitigating IB after compared to before completing the curriculum. Conclusions Despite apparent barriers to clinician participation, we demonstrated feasibility and acceptability of the REACHing Equity intervention. Further research is needed to develop objective measures of uptake and clinician skill, test the impact of REACHing Equity on clinically relevant outcomes, and refine the curriculum for uptake and dissemination. ClinicalTrials.gov ID: NCT03415308.
Background Patients with atrial fibrillation who are vitamin K antagonist (VKA)-naive may have a higher risk of thrombosis and/or bleeding than VKA-experienced patients. Methods and results Using ...data from ARISTOTLE, we assessed baseline characteristics and the treatment effect of apixaban versus warfarin in the VKA-naive and VKA-experienced cohorts. We compared rates of study drug discontinuation and time-in-therapeutic range. Overall, 7,800 (43%) were VKA naive, and 10,401 were VKA experienced. At baseline, both groups were similar with respect to age and congestive heart failure, hypertension, age, diabetes, stroke score (CHADS2 ). Fewer VKA-naive patients had a history of prior stroke (18% vs 21%) or prior bleeding (10% vs 22%) and were more often female (39% vs 33%). The effect of apixaban on the primary efficacy and safety outcomes was similar in VKA-naive (stroke/systemic embolism: hazard ratio HR 0.86, 95% CI 0.67-1.11 and major bleeding: HR 0.73, 95% CI 0.59-0.91) and VKA-experienced populations (stroke/systemic embolism: HR 0.73, 95% CI 0.57-0.95, P value for interaction = 0.39 and major bleeding: HR 0.66, 95% CI 0.55-0.80, P value for interaction = 0.50). Permanent study drug discontinuation was numerically less likely in patients receiving apixaban whether they were VKA naive (HR for discontinuation: 0.87, 95% CI 0.79-0.95) or VKA experienced (HR for discontinuation: 0.93, 95% CI 0.85-1.02). Among patients receiving warfarin, the mean/median times in therapeutic range were lower in the VKA-naive group (VKA-naive: 57.5/61.4, VKA-experienced: 66.0/69.1, P < .001). Conclusion The treatment effects of apixaban (vs warfarin) were not modified by VKA naivety. The rates of stroke/systemic embolism and major bleeding were numerically lower among the patients assigned to apixaban, irrespective of prior VKA use.
Apixaban is an oral, direct factor Xa inhibitor under development for secondary prevention in acute coronary syndrome (ACS). Apixaban's effect on D-dimer and prothrombin fragment 1.2 (F1.2) ...(coagulation activity biomarkers ) was determined in a randomised, double-blinded, placebo-controlled, phase 2 study. Patients (n=1,715) with either ST- segment elevation or non-ST-segment elevation ACS received either placebo or apixaban 2.5 mg twice daily, 10 mg once daily, 10 mg twice daily or 20 mg once daily for six months. Samples were obtained at baseline (before study drug administration), week 3 and week 26. Apixaban plasma concentrations were measured directly by liquid chromatography/mass spectometry, and anti-Xa activity was determined using apixaban as a reference standard. D-dimer and F 1.2 were measured using ELISA-based methods. Most patients had elevated D-dimer and F1.2 levels at baseline. Both coagulation activity biomarkers decreased by week 3 in all treatment groups, but to a greater degree with apixaban than placebo (p<0.001). In a multivariable analysis, apixaban was independently associated with a change in biomarkers over time (p<0.0001). While the overall decrease did not differ significantly among the three highest apixaban doses, F1.2 was suppressed more rapidly by the 10 mg once daily than the 2.5 mg twice daily dose (p<0.05). There was a strong and direct relationship between apixaban plasma concentrations and anti-Xa-apixaban levels, and an inverse relationship for both measures with coagulation activity biomarkers. In conclusion, the oral direct factor Xa inhibitor apixaban significantly reduced coagulation activity biomarkers among patients with ACS. The 10 mg once daily dose reduced thrombin generation (F 1.2) and fibrin formation (D-dimer) more rapidly and robustly than the 2.5 mg twice daily dose. The effect on both D-dimer and F 1.2 was apixaban concentration-and factor Xa inhibition dependent, durable and provided general guidance for dose selection in phase 3 investigation.
Clinician burnout poses risks not just to clinicians but also to patients and the health system. Cardiologists might be especially prone to burnout due to performing high-risk procedures, having to ...discuss serious news, and treating diseases that incur significant morbidity and mortality. Few have attempted to examine which cardiologists might be at higher risk of burnout. Knowing at-risk cardiologists can help frame resilience interventions.
We enrolled 41 cardiologists across five ambulatory cardiology clinics into a randomized controlled trial where we assessed the Maslach Burnout Inventory at baseline. We used bivariate analyses to assess associations between cardiologist demographics and burnout.
Cardiologists reported low burnout for depersonalization and personal accomplishment and moderate levels for emotional exhaustion. Female cardiologists reported emotional exhaustion scores in the "low" range (M = 12.3; SD = 10.06), compared to male cardiologists whose score was in the "moderate" range 19.6 (SD = 9.59;
= 0.113). Cardiologists who had greater than 15 years in practice reported higher mean scores of emotional exhaustion, indicating moderate burnout (M = 20.0, SD = 10.63), compared to those with less than 15 years in practice (M = 16.6, SD = 9.10;
= 0.271).
In this sample, unlike prior studies, male cardiologists reported more burnout. Consistent with prior work, mid-level cardiologists might be at highest risk of emotional exhaustion.
PDF
