The impact of discontinuing single-room isolation of patients with vancomycin-resistant enterococci: a quasi-experimental single-centre study in South Korea

OBJECTIVES

There is limited data on the effects of discontinuing single-room isolation while maintaining contact precautions, such as the use of gowns and gloves. In April 2021, our hospital ceased single-room isolation for patients with vancomycin-resistant enterococci (VRE) because of single-room unavailability. This study assessed the impact of this policy by examining the incidence of hospital-acquired VRE bloodstream infections (HA-VRE BSI).

METHODS

This retrospective quasi-experimental study was conducted at a tertiary-care hospital in Seoul, South Korea. Time-series analysis was used to evaluate HA-VRE BSI incidence at the hospital level and in the haematology unit before (phase 1) and after (phase 2) the policy change.

RESULTS

At the hospital level, HA-VRE BSI incidence level (VRE BSI per 1000 patient-days per month) and trend did not change significantly between phase 1 and phase 2 (coefficient -0.015, 95% confidence interval (CI): -0.053 to 0.023, P=0.45 and 0.000, 95% CI: -0.002 to 0.002, P=0.84, respectively). Similarly, HA-VRE BSI incidence level and trend in the haematology unit (-0.285, 95% CI: -0.618 to 0.048, P=0.09 and -0.018, 95% CI: -0.036 to 0.000, P = 0.054, respectively) did not change significantly across the two phases.

CONCLUSIONS

Discontinuing single-room isolation of VRE-colonized or infected patients was not associated with an increase in the incidence of VRE BSI at the hospital level or among high-risk patients in the haematology unit. Horizontal intervention for multi-drug-resistant organisms, including measures such as enhanced hand hygiene and environmental cleaning, may be more effective at preventing VRE transmission.

Integrated annotation prioritizes metabolites with bioactivity in inflammatory bowel disease

Microbial biochemistry is central to the pathophysiology of inflammatory bowel diseases (IBD). Improved knowledge of microbial metabolites and their immunomodulatory roles is thus necessary for diagnosis and management. Here, we systematically analyzed the chemical, ecological, and epidemiological properties of ~82k metabolic features in 546 Integrative Human Microbiome Project (iHMP/HMP2) metabolomes, using a newly developed methodology for bioactive compound prioritization from microbial communities. This suggested >1000 metabolic features as potentially bioactive in IBD and associated ~43% of prevalent, unannotated features with at least one well-characterized metabolite, thereby providing initial information for further characterization of a significant portion of the fecal metabolome. Prioritized features included known IBD-linked chemical families such as bile acids and short-chain fatty acids, and less-explored bilirubin, polyamine, and vitamin derivatives, and other microbial products. One of these, nicotinamide riboside, reduced colitis scores in DSS-treated mice. The method, MACARRoN, is generalizable with the potential to improve microbial community characterization and provide therapeutic candidates.

Efficacy of immune checkpoint inhibitors in alveolar soft-part sarcoma: results from a retrospective worldwide registry

BACKGROUND

Conventional cytotoxic drugs are not effective in alveolar soft-part sarcoma (ASPS). Immune checkpoint (programmed cell death protein 1/programmed death-ligand 1) inhibitors (ICIs) are promising drugs in ASPS. A worldwide registry explored the efficacy of ICI in ASPS.

MATERIALS AND METHODS

Data from adult patients diagnosed with ASPS and treated with ICI for advanced disease in expert sarcoma centers from Europe, Australia and North America were retrospectively collected, including demographics and data related to treatments and outcome.

RESULTS

Seventy-six ASPS patients, with a median age at diagnosis of 25 years (range 3-61 years), were registered. All patients received ICI for metastatic disease. Immunotherapy regimens consisted of monotherapy in 38 patients (50%) and combination in 38 (50%) (23 with a tyrosine kinase inhibitor). Among the 68 assessable patients, there were 3 complete responses and 34 partial responses, translating into an overall response rate of 54.4%. After a median follow-up of 36 months [95% confidence interval (CI) 32-40 months] since the start of immunotherapy, 45 (59%) patients have progressed on ICI, with a median progression-free survival (PFS) of 16.3 months (95% CI 8-25 months). Receiving ICI in first line (P = 0.042) and achieving an objective response (P = 0.043) correlated with a better PFS. Median estimated overall survival (OS) from ICI initiation has not been reached. The 12-month and 24-month OS rates were 94% and 81%, respectively.

CONCLUSIONS

This registry constitutes the largest available series of ASPS treated with ICI. Our results suggest that the ICI treatment provides long-lasting disease control and prolonged OS in patients with advanced ASPS, an ultra-rare entity with limited active therapeutic options.

Impact of carbapenem-targeted antimicrobial stewardship interventions: an interrupted time-series analysis

BACKGROUND

The development of carbapenem-resistant Gram-negative bacilli (CR-GNB) is largely favoured by indiscriminate and prolonged carbapenem use, which is a significant contributing factor.

AIM

To evaluate the impact of two carbapenem antibiotic stewardship programme interventions on both carbapenem prescriptions and the clinical isolation rates of CR-GNBs, using interrupted time-series analysis.

METHODS

A time-series analysis was performed using data for carbapenem usage from a tertiary hospital in South Korea from January 2017 to July 2022. Two carbapenem antibiotic stewardship programme interventions were implemented sequentially: (i) a prospective audit and feedback (PAF) from November 2018 to April 2020 (intervention 1), and (ii) preauthorization from May 2020 to August 2020 (intervention 2). Monthly carbapenem usage and incidence of CR-GNB before and after each intervention were compared using an autoregressive integrated moving average model.

FINDINGS

Implementation of PAF resulted in a significant reduction in carbapenem consumption, followed by an additional decrease after the preauthorization was implemented. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae increased after intervention 1, but there was a significant change from an increasing trend to a stationary trend after intervention 2. The incidence of carbapenem-resistant Pseudomonas aeruginosa, which had increased during the baseline period, became stationary after intervention 1. A significant decrease was observed in the incidence of carbapenem-resistant Acinetobacter baumannii during the implementation of intervention 1 and 2.

CONCLUSION

This study emphasizes the importance of adopting comprehensive antibiotic management and rigorous infection control to prevent infections caused by antibiotic-resistant bacteria.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea

BACKGROUND

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes.

AIM

To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI).

METHODS

Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI.

RESULTS

This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI.

CONCLUSIONS

This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Natural aging and Alzheimer's disease pathology increase susceptibility to focused ultrasound-induced blood-brain barrier opening

Focused Ultrasound (FUS) paired with systemically-injected microbubbles (μB) is capable of transiently opening the blood-brain barrier (BBBO) for noninvasive and targeted drug delivery to the brain. FUS-BBBO is also capable of modulating the neuroimmune system, further qualifying its therapeutic potential for neurodegenerative diseases like Alzheimer's disease (AD). Natural aging and AD impose significant strain on the brain and particularly the BBB, modifying its structure and subsequently, its functionality. The emerging focus on treating neurodegenerative diseases with FUS-BBBO necessitates an investigation into the extent that age and AD affect the BBB's response to FUS. FUS-BBBO was performed with a 1.5-MHz, geometrically focused transducer operated at 450 kPa and paired with a bolus microbubble injection of 8 × 108 μB/mL. Here we quantify the BBBO, BBB closing (BBBC) timeline, and BBB permeability (BBBP) following FUS-BBBO in male mice with and without AD pathology, aged 10 weeks, one year, or two years. The data presented herein indicates that natural aging and AD pathology may increase initial BBBO volume by up to 34.4% and 40.7% respectively, extend BBBC timeline by up to 1.3 and 1.5 days respectively, and increase BBBP as measured by average Ktrans values up to 80% and 86.1% respectively in male mice. This characterization of the BBB response to FUS-BBBO with age and AD further clarifies the nature and extent of the functional impact of these factors and may offer new considerations for planning FUS-BBBO interventions in aged and AD populations.

Engineered Escherichia coli for the in situ secretion of therapeutic nanobodies in the gut

Drug platforms that enable the directed delivery of therapeutics to sites of diseases to maximize efficacy and limit off-target effects are needed. Here, we report the development of PROT3EcT, a suite of commensal Escherichia coli engineered to secrete proteins directly into their surroundings. These bacteria consist of three modular components: a modified bacterial protein secretion system, the associated regulatable transcriptional activator, and a secreted therapeutic payload. PROT3EcT secrete functional single-domain antibodies, nanobodies (Nbs), and stably colonize and maintain an active secretion system within the intestines of mice. Furthermore, a single prophylactic dose of a variant of PROT3EcT that secretes a tumor necrosis factor-alpha (TNF-α)-neutralizing Nb is sufficient to ablate pro-inflammatory TNF levels and prevent the development of injury and inflammation in a chemically induced model of colitis. This work lays the foundation for developing PROT3EcT as a platform for the treatment of gastrointestinal-based diseases.

Gut microbial metabolism of 5-ASA diminishes its clinical efficacy in inflammatory bowel disease

For decades, variability in clinical efficacy of the widely used inflammatory bowel disease (IBD) drug 5-aminosalicylic acid (5-ASA) has been attributed, in part, to its acetylation and inactivation by gut microbes. Identification of the responsible microbes and enzyme(s), however, has proved elusive. To uncover the source of this metabolism, we developed a multi-omics workflow combining gut microbiome metagenomics, metatranscriptomics and metabolomics from the longitudinal IBDMDB cohort of 132 controls and patients with IBD. This associated 12 previously uncharacterized microbial acetyltransferases with 5-ASA inactivation, belonging to two protein superfamilies: thiolases and acyl-CoA N-acyltransferases. In vitro characterization of representatives from both families confirmed the ability of these enzymes to acetylate 5-ASA. A cross-sectional analysis within the discovery cohort and subsequent prospective validation within the independent SPARC IBD cohort (n = 208) found three of these microbial thiolases and one acyl-CoA N-acyltransferase to be epidemiologically associated with an increased risk of treatment failure among 5-ASA users. Together, these data address a longstanding challenge in IBD management, outline a method for the discovery of previously uncharacterized gut microbial activities and advance the possibility of microbiome-based personalized medicine.

Risk of transmission of COVID-19 from healthcare workers returning to work after a 5-day isolation, and kinetics of shedding of viable SARS-CoV-2 variant B.1.1.529 (Omicron)

BACKGROUND

There have been limited data on the risk of onward transmission from individuals with Omicron variant infections who return to work after a 5-day isolation.

AIM

To evaluate the risk of transmission from healthcare workers (HCWs) with Omicron variant who returned to work after a 5-day isolation and the viable-virus shedding kinetics.

METHODS

This investigation was performed in a tertiary care hospital, Seoul, South Korea. In a secondary transmission study, we retrospectively reviewed the data of HCWs confirmed as COVID-19 from March 14^th to April 3^rd, 2022 in units with five or more COVID-19-infected HCWs per week. In the viral shedding kinetics study, HCWs with Omicron variant infection who agreed with daily saliva sampling were enrolled between February and March, 2022.

FINDINGS

Of the 248 HCWs who were diagnosed with COVID-19 within 5 days of the return of an infected HCW, 18 (7%) had contact with the returned HCW within 1-5 days after their return. Of these, nine (4%) had an epidemiologic link other than with the returning HCW, and nine (4%) had contact with the returning HCW, without any other epidemiologic link. In the study of the kinetics of virus shedding (N = 32), the median time from symptom onset to negative conversion of viable virus was four days (95% confidence interval: 3-5).

CONCLUSION

Our data suggest that the residual risk of virus transmission after 5 days of isolation following diagnosis or symptom onset is low.

β-Delayed One and Two Neutron Emission Probabilities Southeast of ^{132}Sn and the Odd-Even Systematics in r-Process Nuclide Abundances

The β-delayed one- and two-neutron emission probabilities (P_{1n} and P_{2n}) of 20 neutron-rich nuclei with N≥82 have been measured at the RIBF facility of the RIKEN Nishina Center. P_{1n} of ^{130,131}Ag, ^{133,134}Cd, ^{135,136}In, and ^{138,139}Sn were determined for the first time, and stringent upper limits were placed on P_{2n} for nearly all cases. β-delayed two-neutron emission (β2n) was unambiguously identified in ^{133}Cd and ^{135,136}In, and their P_{2n} were measured. Weak β2n was also detected from ^{137,138}Sn. Our results highlight the effect of the N=82 and Z=50 shell closures on β-delayed neutron emission probability and provide stringent benchmarks for newly developed macroscopic-microscopic and self-consistent global models with the inclusion of a statistical treatment of neutron and γ emission. The impact of our measurements on r-process nucleosynthesis was studied in a neutron star merger scenario. Our P_{1n} and P_{2n} have a direct impact on the odd-even staggering of the final abundance, improving the agreement between calculated and observed Solar System abundances. The odd isotope fraction of Ba in r-process-enhanced (r-II) stars is also better reproduced using our new data.

The relative importance of left atria reservoir strain compared with components of HFA-PEFF diagnostic algorithm

Background/Introduction

The relative importance of the left atrial reservoir strain (LARS) compared to the parameters constituting the HFA-PEFF score developed as a diagnostic tool for patients with heart failure with preserved ejection fraction (HFpEF) is not well known.

Purpose

We aimed to identify the relative importance of LARS compared with variables associated with HFpEF and HFA-PEFF score including echocardiographic parameters, demographic data, and NT-proBNP.

Methods

From August 2021 to March 2022, we obtained data retrospectively from the participants visiting our clinic in a single cardiovascular center. The 1,252 participants with sinus rhythm and ejection fraction more than 50% were enrolled in the present study (61.8±16.6 years and 55% female). Multivariable regression analysis using backward elimination and random forest analysis, supervised learning algorithm, were performed to identify the relative importance of LARS on the HFA-PEFF score.

Results

The median HFA-PEFF score was 3 points (interquartile range 2 to 4 points). Two hundred forty-one subjects (19.2%) had more than 5 points. LARS showed a moderate correlation with the HFA-PEFF score (r=−0.632, p<0.001). In multivariable regression analysis, LARS was independent variable affecting HFA-PEFF score with female sex, left atrial volume index (LAVI), septal e', E over e' (septal), the maximal tricuspid regurgitation velocity (TR-Vmax), left ventricular global longitudinal strain (LV-GLS), NT-proBNP, interventricular septal wall thickness (standardized β=−0.106; P<0.001). In random forest analysis, LARS was a more relatively important variable than TR-Vmax, NT-proBNP, septal E/e', septal e', the major echocardiographic components of HFA-PEFF score estimating more than 5 points of HFA-PEFF score.

Conclusions

LA reservoir strain is one of the important factors with components of the HFA-PEFF score which is a useful tool to assess the patients with HFpEF.

Funding Acknowledgement

Type of funding sources: None.

Faecalibaculum rodentium remodels retinoic acid signaling to govern eosinophil-dependent intestinal epithelial homeostasis

The intestinal epithelium plays critical roles in sensing and integrating dietary and microbial signals. How microbiota and intestinal epithelial cell (IEC) interactions regulate host physiology in the proximal small intestine, particularly the duodenum, is unclear. Using single-cell RNA sequencing of duodenal IECs under germ-free (GF) and different conventional microbiota compositions, we show that specific microbiota members alter epithelial homeostasis by increasing epithelial turnover rate, crypt proliferation, and major histocompatibility complex class II (MHCII) expression. Microbiome profiling identified Faecalibaculum rodentium as a key species involved in this regulation. F. rodentium decreases enterocyte expression of retinoic-acid-producing enzymes Adh1, Aldh1a1, and Rdh7, reducing retinoic acid signaling required to maintain certain intestinal eosinophil populations. Eosinophils suppress intraepithelial-lymphocyte-mediated production of interferon-γ that regulates epithelial cell function. Thus, we identify a retinoic acid-eosinophil-interferon-γ-dependent circuit by which the microbiota modulates duodenal epithelial homeostasis.

A biosynthetic pathway for the selective sulfonation of steroidal metabolites by human gut bacteria

Members of the human gut microbiome enzymatically process many bioactive molecules in the gastrointestinal tract. Most gut bacterial modifications characterized so far are hydrolytic or reductive in nature. Here we report that abundant human gut bacteria from the phylum Bacteroidetes perform conjugative modifications by selectively sulfonating steroidal metabolites. While sulfonation is a ubiquitous biochemical modification, this activity has not yet been characterized in gut microbes. Using genetic and biochemical approaches, we identify a widespread biosynthetic gene cluster that encodes both a sulfotransferase (BtSULT, BT0416) and enzymes that synthesize the sulfonate donor adenosine 3'-phosphate-5'-phosphosulfate (PAPS), including an APS kinase (CysC, BT0413) and an ATP sulfurylase (CysD and CysN, BT0414-BT0415). BtSULT selectively sulfonates steroidal metabolites with a flat A/B ring fusion, including cholesterol. Germ-free mice monocolonized with Bacteroides thetaiotaomicron ΔBT0416 exhibited reduced gastrointestinal levels of cholesterol sulfate (Ch-S) compared with wild-type B. thetaiotaomicron-colonized mice. The presence of BtSULT and BtSULT homologues in bacteria inhibited leucocyte migration in vitro and in vivo, and abundances of cluster genes were significantly reduced in patients with inflammatory bowel disease. Together, these data provide a mechanism by which gut bacteria sulfonate steroidal metabolites and suggest that these compounds can modulate immune cell trafficking in the host.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Assessing The Utility of D-Dimer Driven Anticoagulation Strategies In Severely Obese Patients With COVID-19

Funding Acknowledgements

Type of funding sources: None.

Background

Many studies to date have documented significant inflammatory vascular sequelae in association with COVID-19. Current guidelines suggest an initial strategy of therapeutic-dose anticoagulation to non-critically ill, hospitalized patients requiring low-flow oxygen and a concurrent D-dimer level above the upper limit of normal. However, the utility of D-dimer values in predicting thrombosis in severely obese patients are equivocal to poor, with prior evidence suggesting falsely elevated levels with greater BMI. Given the weight-based dosing of heparin, these patients may also be inadvertently at elevated risk for major bleeds.

Purpose

To examine the utility of D-dimer levels in risk stratification and anticoagulation therapy in non-critically ill COVID-19 patients with severe obesity.

Methods

In this single-center, retrospective study, 32 severely obese patients (defined as BMI > 40) hospitalized with COVID-19 and requiring low flow oxygen delivery, without ICU level of care were analyzed. Clinical outcomes were compared between groups receiving therapeutic versus prophylactic doses of anticoagulation. All were treated with low molecular weight heparin (LMWH) per hospital protocol. The following data points were examined: length of hospitalization, mortality, anticoagulation therapy, initial d-dimer levels, thrombotic events, minor/major bleeds, and oxygen modality.

Results

In total, 78% of patients initially presented with a D-dimer level above the upper limit of normal, with 53% of patients meeting criteria for therapeutic anticoagulation. However, there were no significant differences in incidence of thrombotic events, mean length of hospitalization or overall mortality. Furthermore, despite utilization of appropriate therapeutic anticoagulation, it did not reduce the overall use of oxygen support requirements, including high flow oxygen or non-invasive ventilation, when compared to individuals receiving prophylactic dosing.

Conclusion

The clinical utility of D-dimer levels for guiding anticoagulation therapy in severely obese patients with COVID-19 may be limited. Here, we demonstrate that therapeutic dose approaches have nonsignificant differences in clinical outcomes when compared to prophylactic doses in this distinct population.

Discovery of bioactive microbial gene products in inflammatory bowel disease

Microbial communities and their associated bioactive compounds^1-3 are often disrupted in conditions such as the inflammatory bowel diseases (IBD)⁴. However, even in well-characterized environments (for example, the human gastrointestinal tract), more than one-third of microbial proteins are uncharacterized and often expected to be bioactive^5-7. Here we systematically identified more than 340,000 protein families as potentially bioactive with respect to gut inflammation during IBD, about half of which have not to our knowledge been functionally characterized previously on the basis of homology or experiment. To validate prioritized microbial proteins, we used a combination of metagenomics, metatranscriptomics and metaproteomics to provide evidence of bioactivity for a subset of proteins that are involved in host and microbial cell-cell communication in the microbiome; for example, proteins associated with adherence or invasion processes, and extracellular von Willebrand-like factors. Predictions from high-throughput data were validated using targeted experiments that revealed the differential immunogenicity of prioritized Enterobacteriaceae pilins and the contribution of homologues of von Willebrand factors to the formation of Bacteroides biofilms in a manner dependent on mucin levels. This methodology, which we term MetaWIBELE (workflow to identify novel bioactive elements in the microbiome), is generalizable to other environmental communities and human phenotypes. The prioritized results provide thousands of candidate microbial proteins that are likely to interact with the host immune system in IBD, thus expanding our understanding of potentially bioactive gene products in chronic disease states and offering a rational compendium of possible therapeutic compounds and targets.

Human gut bacteria produce ΤΗ17-modulating bile acid metabolites

The microbiota modulates gut immune homeostasis. Bacteria influence the development and function of host immune cells, including T helper cells expressing interleukin-17A (TH17 cells). We previously reported that the bile acid metabolite 3-oxolithocholic acid (3-oxoLCA) inhibits TH17 cell differentiation1. Although it was suggested that gut-residing bacteria produce 3-oxoLCA, the identity of such bacteria was unknown, and it was unclear whether 3-oxoLCA and other immunomodulatory bile acids are associated with inflammatory pathologies in humans. Here we identify human gut bacteria and corresponding enzymes that convert the secondary bile acid lithocholic acid into 3-oxoLCA as well as the abundant gut metabolite isolithocholic acid (isoLCA). Similar to 3-oxoLCA, isoLCA suppressed TH17 cell differentiation by inhibiting retinoic acid receptor-related orphan nuclear receptor-γt, a key TH17-cell-promoting transcription factor. The levels of both 3-oxoLCA and isoLCA and the 3α-hydroxysteroid dehydrogenase genes that are required for their biosynthesis were significantly reduced in patients with inflammatory bowel disease. Moreover, the levels of these bile acids were inversely correlated with the expression of TH17-cell-associated genes. Overall, our data suggest that bacterially produced bile acids inhibit TH17 cell function, an activity that may be relevant to the pathophysiology of inflammatory disorders such as inflammatory bowel disease.

Study Protocol of a Comprehensive Activity Promotion Program for the Prevention of Dementia: A Randomized Controlled Trial Protocol

BACKGROUND

Several technical devices are available to monitor and promote changes in behavior toward higher activity. In particular, smartphones are becoming the primary platform for recognizing human activity. However, the effects of behavior change techniques that promote physical, cognitive, and social activities on incident dementia in older adults remain unknown.

OBJECTIVES

This randomized controlled trial aims to examine the effects of behavior change techniques on the prevention of dementia among community-dwelling older adults using a smartphone as a behavior change tool.

DESIGN

A randomized controlled trial.

SETTING

Community in Japan.

PARTICIPANTS

The study cohort comprises 3,498 individuals, aged ≥60 years, randomized into two groups: the smartphone group (n = 1,749) and the control group (n = 1,749).

INTERVENTION

The smartphone group will be asked to use smartphone applications for at least 30 minutes daily to self-manage and improve their physical, cognitive, and social activities. The smartphone group will perform 60-minute group walking sessions using application-linked Nordic walking poles with cognitive stimulation twice a week during the intervention period. The walking poles are a dual-task exercise tool that works with a smartphone to perform cognitive tasks while walking, and the poles are equipped with switches to answer questions for simple calculation and memory tasks. The smartphone and control groups will receive lectures about general health that will be provided during the baseline and follow-up assessments.

MEASUREMENTS

Incident dementia will be detected using cognitive tests (at baseline, after 15 months, and after 30 months) and by preparing diagnostic monthly reports based on data from the Japanese Health Insurance System. Participants without dementia at baseline who will be diagnosed with dementia over the 30-month follow-up period will be considered to have incident dementia.

CONCLUSIONS

This study has the potential to provide the first evidence of the effectiveness of information communication technology and Internet of Things in incident dementia. If our trial results show a delayed dementia onset for self-determination interventions, the study protocol will provide a cost-effective and safe method for maintaining healthy cognitive aging.

Association of Daily Physical Activity with Disability in Community-Dwelling Older Adults With/Without Chronic Kidney Disease

OBJECTIVES

Physical activity is recommended for disability prevention in the older adult population; however, the level of physical activity required for older adults with chronic kidney disease (CKD) remains unknown. This study aimed to examine the associations between daily physical activity and disability incidence in older adults with and without CKD to determine relevant daily physical activity levels.

DESIGN

Prospective observational study.

SETTING AND PARTICIPANTS

3,786 community-dwelling older adults aged ≥65 years.

MEASUREMENTS

Mean daily times spent in light- (LPA) and moderate-to-vigorous physical activity (MVPA) were measured using triaxial accelerometers. CKD was defined by a creatinine estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Disability incidence was identified as long-term care insurance certification during a 60-month follow-up period. Associations between physical activity and disability incidence were examined using Cox proportional hazard models stratified by the CKD status. Non-linear and linear associations were tested using the restricted cubic spline.

RESULTS

A total of 1,054 individuals were identified to have CKD. Disability incidence was higher in the CKD group than in the non-CKD group. The adjusted cox proportional hazard models indicated that a 10-minute increase in MVPA time was associated with lower disability incidence in the non-CKD group (hazard ratio [HR], 0.838; 95% confidence interval [CI]: 0.764-0.918) and the CKD group (HR, 0.859; 95% CI: 0.766-0.960). Linear associations were observed in MVPA for the non-CKD and CKD groups.

CONCLUSION

Increasing MVPA was associated with lower disability incidence in older adults with and without CKD. These findings can help devise disability prevention strategies for older CKD patients.

Association between Non-Face-to-Face Interactions and Incident Disability in Older Adults

OBJECTIVES

This observational prospective cohort study, conducted between September 2015 and February 2019, aimed to investigate the association between the incidence of disability and non-face-to-face interactions among community-dwelling older adults in Japan.

DESIGN

Participants reported their interaction status using a self-report questionnaire. Face-to-face interactions comprised in-person meetings, while virtual interactions (e.g., via phone calls or emails) were defined as non-face-to-face interactions. We examined the relationship between their interaction status at baseline and the risk of disability incidence at follow-up. We also considered several potential confounding variables, such as demographic characteristics.

SETTING

The National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes.

PARTICIPANTS

We included 1159 adults from Takahama City aged ≥75 years (mean age ± standard deviation = 79.5 ± 3.6 years).

MEASUREMENTS

Interaction status was assessed using a self-reported questionnaire consisting of two sections (face-to-face and non-face-to-face interactions), and four questionnaire items. Based on the responses we categorized study participants into four groups: "both interactions," "face-to-face only," "non-face-to-face only," and "no interactions."

RESULTS

Individuals with both kinds of interactions (49.3/1000 person-years) or only one kind of interaction (face-to-face = 57.7/1000 person-years; non-face-to-face = 41.2 person-years) had lower incidence of disability than those with no interactions (88.9/1000 person-years). Moreover, the hazard ratios adjusted for potential confounding factors for the incidence of disability in the both interaction, face-to-face-only, and non-face-to-face only groups were 0.57 (confidence interval = 0.39-0.82; p = 0.003), 0.66 (confidence interval = 0.44-0.98; p = 0.038), and 0.47 (confidence interval = 0.22-0.99; p = 0.048), respectively.

CONCLUSION

Considering the interaction status of older adults in their day-to-day practice, clinicians may be able to achieve better outcomes in the primary prevention of disease by encouraging older adults to engage in any form of interaction, including non-face-to-face interactions.

A bacterial bile acid metabolite modulates Treg activity through the nuclear hormone receptor NR4A1

Bile acids act as signaling molecules that regulate immune homeostasis, including the differentiation of CD4+ T cells into distinct T cell subsets. The bile acid metabolite isoallolithocholic acid (isoalloLCA) enhances the differentiation of anti-inflammatory regulatory T cells (Treg cells) by facilitating the formation of a permissive chromatin structure in the promoter region of the transcription factor forkhead box P3 (Foxp3). Here, we identify gut bacteria that synthesize isoalloLCA from 3-oxolithocholic acid and uncover a gene cluster responsible for the conversion in members of the abundant human gut bacterial phylum Bacteroidetes. We also show that the nuclear hormone receptor NR4A1 is required for the effect of isoalloLCA on Treg cells. Moreover, the levels of isoalloLCA and its biosynthetic genes are significantly reduced in patients with inflammatory bowel diseases, suggesting that isoalloLCA and its bacterial producers may play a critical role in maintaining immune homeostasis in humans.

Clustering and multiple-spreading events of nosocomial severe acute respiratory syndrome coronavirus 2 infection

Background

There is growing evidence that super-spreading events (SSEs) and multiple-spreading events (MSEs) are a characteristic feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, data regarding the possibility of SSEs or MSEs in healthcare settings are limited.

Methods

This study was performed at a tertiary-care hospital in Korea. We analysed the nosocomial COVID-19 cases that occurred in healthcare workers and inpatients and their caregivers between January and 20^th December 2020. Cases with two to four secondary cases were defined as MSEs and those with five or more secondary cases as SSEs.

Findings

We identified 21 nosocomial events (single-case events, N = 12 (57%); MSE + SSE, N = 9 (43%)) involving 65 individuals with COVID-19. Of these 65 individuals, 21 (32%) were infectors. The infectors tended to have a longer duration between symptom onset and diagnostic confirmation than did the non-infectors (median two days vs zero days, P=0.08). Importantly, 12 (18%) individuals were responsible for MSEs and one (2%) for an SSE, which collectively generated 35 (54%) secondary cases.

Conclusion

In a hospital with thorough infection-control measures, approximately 70% of the nosocomial cases of COVID-19 did not generate secondary cases, and one-fifth of the infectors were responsible for SSEs and MSEs, which accounted for approximately half of the total cases. Early case identification, isolation, and extensive contact tracing are important for the prevention of transmission and SSEs.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Development and Validation of a Deep Learning-Based Model to Distinguish Glioblastoma from Solitary Brain Metastasis Using Conventional MR Images

BACKGROUND AND PURPOSE

Differentiating glioblastoma from solitary brain metastasis preoperatively using conventional MR images is challenging. Deep learning models have shown promise in performing classification tasks. The diagnostic performance of a deep learning-based model in discriminating glioblastoma from solitary brain metastasis using preoperative conventional MR images was evaluated.

MATERIALS AND METHODS

Records of 598 patients with histologically confirmed glioblastoma or solitary brain metastasis at our institution between February 2006 and December 2017 were retrospectively reviewed. Preoperative contrast-enhanced T1WI and T2WI were preprocessed and roughly segmented with rectangular regions of interest. A deep neural network was trained and validated using MR images from 498 patients. The MR images of the remaining 100 were used as an internal test set. An additional 143 patients from another tertiary hospital were used as an external test set. The classifications of ResNet-50 and 2 neuroradiologists were compared for their accuracy, precision, recall, F1 score, and area under the curve.

RESULTS

The areas under the curve of ResNet-50 were 0.889 and 0.835 in the internal and external test sets, respectively. The area under the curve of neuroradiologists 1 and 2 were 0.889 and 0.768 in the internal test set and 0.857 and 0.708 in the external test set, respectively.

CONCLUSIONS

A deep learning-based model may be a supportive tool for preoperative discrimination between glioblastoma and solitary brain metastasis using conventional MR images.

In vitro antibacterial effects of non-thermal atmospheric plasma irradiation on Staphylococcus pseudintermedius and Pseudomonas aeruginosa

In the last decade, atmospheric plasma has been used to treating bacterial infections in humans due to its bactericidal effects; however, its efficacy in dogs is unclear. This study evaluated the in vitro bactericidal efficacy of atmospheric plasma on Staphylococcus pseudinter- medius and Pseudomonas aeruginosa, two of the most important bacterial agents isolated from canine pyodermas. Three isolates each of S. pseudintermedius and P. aeruginosa obtained from dogs with pyoderma were subjected to atmospheric plasma. The isolates from the control group were not exposed to plasma, while those from the treatment groups were exposed to plasma for 15 (7.5 J/cm2), 30 (15 J/cm2), 60 (30 J/cm2), or 90 (45 J/cm2) seconds. After each treatment, a reduction in colony formation was observed. Bacterial viability was evaluated using the LIVE/ DEAD® BacLight™ Bacterial Viability Kit. The antibacterial effects were evaluated with Image J software and significance was assessed statistically in comparison to the control group. The bactericidal effect of atmospheric plasma against both bacteria increased significantly in a time-dependent manner. These results demonstrate the bactericidal capacity of atmospheric plasma, and suggest that it could serve as an alternative treatment method for canine pyoderma. Further studies are needed to evaluate the safety and efficacy of atmospheric plasma in dogs.

Whole microbial community viability is not quantitatively reflected by propidium monoazide sequencing approach

BACKGROUND

High-throughput sequencing provides a powerful window into the structural and functional profiling of microbial communities, but it is unable to characterize only the viable portion of microbial communities at scale. There is as yet not one best solution to this problem. Previous studies have established viability assessments using propidium monoazide (PMA) treatment coupled with downstream molecular profiling (e.g., qPCR or sequencing). While these studies have met with moderate success, most of them focused on the resulting "viable" communities without systematic evaluations of the technique. Here, we present our work to rigorously benchmark "PMA-seq" (PMA treatment followed by 16S rRNA gene amplicon sequencing) for viability assessment in synthetic and realistic microbial communities.

RESULTS

PMA-seq was able to successfully reconstruct simple synthetic communities comprising viable/heat-killed Escherichia coli and Streptococcus sanguinis. However, in realistically complex communities (computer screens, computer mice, soil, and human saliva) with E. coli spike-in controls, PMA-seq did not accurately quantify viability (even relative to variability in amplicon sequencing), with its performance largely affected by community properties such as initial biomass, sample types, and compositional diversity. We then applied this technique to environmental swabs from the Boston subway system. Several taxa differed significantly after PMA treatment, while not all microorganisms responded consistently. To elucidate the "PMA-responsive" microbes, we compared our results with previous PMA-based studies and found that PMA responsiveness varied widely when microbes were sourced from different ecosystems but were reproducible within similar environments across studies.

CONCLUSIONS

This study provides a comprehensive evaluation of PMA-seq exploring its quantitative potential in synthetic and complex microbial communities, where the technique was effective for semi-quantitative purposes in simple synthetic communities but provided only qualitative assessments in realistically complex community samples. Video abstract.

Fusobacterium nucleatum drives a pro-inflammatory intestinal microenvironment through metabolite receptor-dependent modulation of IL-17 expression

The colorectal cancer (CRC)-associated microbiota creates a pro-tumorigenic intestinal milieu and shapes immune responses within the tumor microenvironment. However, how oncomicrobes - like Fusobacterium nucleatum, found in the oral cavity and associated with CRC tissues- affect these distinct aspects of tumorigenesis is difficult to parse. Herein, we found that neonatal inoculation of ApcMin/+ mice with F. nucleatum strain Fn7-1 circumvents technical barriers preventing its intestinal colonization, drives colonic Il17a expression prior to tumor formation, and potentiates intestinal tumorigenesis. Using gnotobiotic mice colonized with a minimal complexity microbiota (the altered Schaedler's flora), we observed that intestinal Fn7-1 colonization increases colonic Th17 cell frequency and their IL-17A and IL-17F expression, along with a concurrent increase in colonic lamina propria Il23p19 expression. As Fn7-1 stably colonizes the intestinal tract in our models, we posited that microbial metabolites, specifically short-chain fatty acids (SCFA) that F. nucleatum abundantly produces in culture and, as we demonstrate, in the intestinal tract, might mediate part of its immunomodulatory effects in vivo. Supporting this hypothesis, we found that Fn7-1 did not alter RORγt+ CD4+T cell frequency in the absence of the SCFA receptor FFAR2. Taken together, our work suggests that F. nucleatum influences intestinal immunity by shaping Th17 responses in an FFAR2-dependent manner, although further studies are necessary to clarify the precise and multifaceted roles of FFAR2. The potential to increase intestinal Th17 responses is shared by another oncomicrobe, enterotoxigenic Bacteroides fragilis, highlighting a conserved pathway that could potentially be targeted to slow oncomicrobe-mediated CRC.

Supercapacitor performance of porous nickel cobaltite nanosheets

In this work, nickel cobaltite (NiCo2O4) nanosheets with a porous structure were fabricated on nickel foam as a working electrode for supercapacitor applications. The nanosheets were fabricated by electrochemical deposition of nickel-cobalt hydroxide on the nickel foam substrate at ambient temperature in a three-electrode cell followed by annealing at 300 °C to transform the coating into a porous NiCo2O4 nanosheet. Field emission scanning electron microscopy and transmission electron microscopy revealed a three-dimensional mesoporous structure, which facilitates ion transport and electronic conduction for fast redox reactions. For one cycle, the NiCo2O4 electrodeposited nickel foam has a high specific capacitance (1734.9 F g-1) at a current density (CD) of 2 A g-1. The electrode capacitance decreased by only approximately 12.7% after 3500 cycles at a CD of 30 A g-1. Moreover, a solid-state asymmetric supercapacitor (ASC) was built utilising the NiCo2O4 nanosheets, carbon nanotubes, and a polyvinyl alcohol-potassium hydroxide gel as the anode, cathode, and solid-state electrolyte, respectively. The ASC displayed great electrochemical properties with a 42.25 W h kg-1 energy density at a power density of 298.79 W kg-1.

Hyperattenuating lesions after mechanical thrombectomy in acute ischaemic stroke: factors predicting symptomatic haemorrhage and clinical outcomes

AIM

To evaluate the clinical significance of hyperattenuating lesions on CT after mechanical thrombectomy for acute ischaemic stroke, and to identify imaging factors that predict symptomatic haemorrhage and unfavourable outcomes.

MATERIALS AND METHODS

Seventy-eight patients with acute ischaemic stroke in the anterior circulation who underwent mechanical thrombectomy were evaluated. All patients underwent post-interventional unenhanced computed tomography (CT) within 24 h and follow-up CT or magnetic resonance imaging (MRI) within 7 days. Baseline characteristics and clinical outcomes were compared between patients with and without hyperattenuating lesions. In patients with hyperattenuating lesions, clinical and imaging factors that predict symptomatic haemorrhage and unfavourable outcomes were determined.

RESULTS

Fifty-six of 78 patients (71.8%) demonstrated hyperattenuating lesions on post-interventional CT. Patients with hyperattenuating lesions showed lower Alberta Stroke Program Early CT score (ASPECTS), persistent/symptomatic haemorrhage, and unfavourable outcomes than those without. In patients with hyperattenuating lesions, larger hyperattenuating lesion volume (>21.3 ml; OR, 55.60, p<0.001) and perilesional oedema (OR, 46.04, p=0.015) were independent factors predicting symptomatic haemorrhage. Older age (OR, 1.2, p=0.006) and lower ASPECTS (OR, 0.45, p=0.046) were independent factors predicting unfavourable outcomes in patients with hyperattenuating lesions. Adding the volume of the hyperattenuating lesion to age and ASPECTS increased the predictive performance of unfavourable outcomes (area under the curve 0.874 versus 0.934, p=0.043).

CONCLUSIONS

Hyperattenuating lesions on post-interventional CT are associated with increased risk of symptomatic haemorrhage and unfavourable outcomes. Larger hyperattenuating lesion volume is an independent factor of symptomatic haemorrhage and it has added predictive value for unfavourable outcomes.

GW190521: A Binary Black Hole Merger with a Total Mass of 150 M_{⊙}

On May 21, 2019 at 03:02:29 UTC Advanced LIGO and Advanced Virgo observed a short duration gravitational-wave signal, GW190521, with a three-detector network signal-to-noise ratio of 14.7, and an estimated false-alarm rate of 1 in 4900 yr using a search sensitive to generic transients. If GW190521 is from a quasicircular binary inspiral, then the detected signal is consistent with the merger of two black holes with masses of 85_{-14}^{+21}  M_{⊙} and 66_{-18}^{+17}  M_{⊙} (90% credible intervals). We infer that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65  M_{⊙}. We calculate the mass of the remnant to be 142_{-16}^{+28}  M_{⊙}, which can be considered an intermediate mass black hole (IMBH). The luminosity distance of the source is 5.3_{-2.6}^{+2.4}  Gpc, corresponding to a redshift of 0.82_{-0.34}^{+0.28}. The inferred rate of mergers similar to GW190521 is 0.13_{-0.11}^{+0.30}  Gpc^{-3} yr^{-1}.

Clinical characteristics of asymptomatic and symptomatic patients with mild COVID-19

OBJECTIVES

Detailed knowledge on the prevalence of asymptomatic cases of coronavirus disease 2019 (COVID-19) and the clinical characteristics of mild COVID-19 is essential for effective control of the COVID-19 pandemic. We determined the prevalence of asymptomatic cases of COVID-19 and characterized the symptoms of patients with mild COVID-19.

METHODS

Study participants were recruited from a community facility designated for the isolation of patients without moderate-to-severe symptoms of COVID-19 in South Korea. The prevalence of asymptomatic patients at admission and the detailed symptoms of mild COVID-19 were evaluated through a questionnaire-based survey. Diagnosis of COVID-19 was confirmed by real-time RT-PCR.

RESULTS

Of the 213 individuals with COVID-19, 41 (19.2%) were asymptomatic until admission. Among the remaining patients with mild COVID-19, the most common symptom was cough (40.1%; 69/172), followed by hyposmia (39.5%; 68/172) and sputum (39.5%; 68/172). Of the 68 individuals with hyposmia, 61 (90%) had accompanying symptoms such as hypogeusia, nasal congestion or rhinorrhoea. Fever (>37.5°C) was only observed in 20 (11.6%) individuals.

CONCLUSIONS

As much as one-fifth of individuals with COVID-19 remained asymptomatic from exposure to admission. Hyposmia was quite frequent among individuals with mild COVID-19, but fever was not. Social distancing should be strongly implemented to prevent disease transmission from asymptomatic individuals or those with mild and inconspicuous symptoms.

Expression of Free Fatty Acid Receptor 2 by Dendritic Cells Prevents Their Expression of Interleukin 27 and Is Required for Maintenance of Mucosal Barrier and Immune Response Against Colorectal Tumors in Mice

BACKGROUND & AIMS

Intestinal microbes and their metabolites affect the development of colorectal cancer (CRC). Short-chain fatty acids are metabolites generated by intestinal microbes from dietary fiber. We investigated the mechanisms by which free fatty acid receptor 2 (FFAR2), a receptor for short-chain fatty acids that can affect the composition of the intestinal microbiome, contributes to the pathogenesis of CRC.

METHODS

We performed studies with ApcMin/+ mice, ApcMin/+Ffar2-/- mice, mice with conditional disruption of Ffar2 in dendritic cells (DCs) (Ffar2fl/flCD11c-Cre mice), ApcMin/+Ffar2fl/flCD11c-Cre mice, and Ffar2fl/fl mice (controls); some mice were given dextran sodium sulfate to induce colitis, with or without a FFAR2 agonist or an antibody against interleukin 27 (IL27). Colon and tumor tissues were analyzed by histology, quantitative polymerase chain reaction, and 16S ribosomal RNA gene sequencing; lamina propria and mesenteric lymph node tissues were analyzed by RNA sequencing and flow cytometry. Intestinal permeability was measured after gavage with fluorescently labeled dextran. We collected data on colorectal tumors from The Cancer Genome Atlas.

RESULTS

ApcMin/+Ffar2-/- mice developed significantly more spontaneous colon tumors than ApcMin/+ mice and had increased gut permeability before tumor development, associated with reduced expression of E-cadherin. Colon tumors from ApcMin/+Ffar2-/- mice had a higher number of bacteria than tumors from ApcMin/+ mice, as well as higher frequencies of CD39+CD8+ T cells and exhausted or dying T cells. DCs from ApcMin/+Ffar2-/- mice had an altered state of activation, increased death, and higher production of IL27. Administration of an antibody against IL27 reduced the numbers of colon tumors in ApcMin/+ mice with colitis. Frequencies of CD39+CD8+ T cells and IL27+ DCs were increased in colon lamina propria from Ffar2fl/flCD11c-Cre mice with colitis compared with control mice or mice without colitis. ApcMin/+Ffar2fl/flCD11c-Cre mice developed even more tumors than ApcMin/+Ffar2fl/fl mice, and their tumors had even higher numbers of IL27+ DCs. ApcMin/+ mice with colitis given the FFAR2 agonist developed fewer colon tumors, with fewer IL27+ DCs, than mice not given the agonist. DCs incubated with the FFAR2 agonist no longer had gene expression patterns associated with activation or IL27 production.

CONCLUSIONS

Loss of FFAR2 promotes colon tumorigenesis in mice by reducing gut barrier integrity, increasing tumor bacterial load, promoting exhaustion of CD8+ T cells, and overactivating DCs, leading to their death. Antibodies against IL27 and an FFAR2 agonist reduce tumorigenesis in mice and might be developed for the treatment of CRC.

Global chemical effects of the microbiome include new bile-acid conjugations

A mosaic of cross-phylum chemical interactions occurs between all metazoans and their microbiomes. A number of molecular families that are known to be produced by the microbiome have a marked effect on the balance between health and disease^1-9. Considering the diversity of the human microbiome (which numbers over 40,000 operational taxonomic units¹⁰), the effect of the microbiome on the chemistry of an entire animal remains underexplored. Here we use mass spectrometry informatics and data visualization approaches^11-13 to provide an assessment of the effects of the microbiome on the chemistry of an entire mammal by comparing metabolomics data from germ-free and specific-pathogen-free mice. We found that the microbiota affects the chemistry of all organs. This included the amino acid conjugations of host bile acids that were used to produce phenylalanocholic acid, tyrosocholic acid and leucocholic acid, which have not previously been characterized despite extensive research on bile-acid chemistry¹⁴. These bile-acid conjugates were also found in humans, and were enriched in patients with inflammatory bowel disease or cystic fibrosis. These compounds agonized the farnesoid X receptor in vitro, and mice gavaged with the compounds showed reduced expression of bile-acid synthesis genes in vivo. Further studies are required to confirm whether these compounds have a physiological role in the host, and whether they contribute to gut diseases that are associated with microbiome dysbiosis.

Visceral Fat Accumulation Is Associated with Mild Cognitive Impairment in Community-Dwelling Older Japanese Women

OBJECTIVES

Visceral fat accumulation is detrimental for brain health and is associated with cognitive impairment in older adults. The objectives of the present study were to examine the association between visceral fat accumulation and prevalence of mild cognitive impairment and its subtypes.

DESIGN

a cross-sectional study.

PARTICIPANTS

This study enrolled 6,109 community-dwelling older adults, including 3,434 women (mean age: 74.4 years) and 2,675 men (mean age: 74.3 years). Individuals with dementia, Parkinson's disease, stroke, Mini-Mental State Examination scores ≤23, and who could not perform basic activities of daily living independently were excluded.

MEASUREMENTS

Participants underwent neurocognitive assessments to assess mild cognitive impairment (MCI) and its subtypes. Visceral fat area (VFA) was measured using abdominal bioelectrical impedance analysis. Participants were divided into quartile groups by VFA.

RESULTS

There were 731 (21.3%) women and 562 (21.0%) men with MCI, and the median VFA values were 63.3 cm2 and 96.3 cm2, respectively. Women participants in the second (adjusted odds ratios [aOR], 0.71; 95% confidence interval [95% CI], 0.54-0.94), third (aOR, 0.66; 95% CI, 0.47-0.92), and fourth quartiles of VFA (aOR, 0.62; 95% CI, 0.41-0.93) had a significantly lower risk of MCI than those in the first quartile. Higher VFA quartiles in women were associated with lower risk of non-amnestic MCI. There were no significant differences in men between quartiles.

CONCLUSIONS

Visceral fat accumulation was associated with MCI, especially non-amnestic MCI, in community-dwelling older Japanese women. These results suggest that visceral fat accumulation is partially protective against cognitive impairment.

Anti-obesity effects of Korean red ginseng extract in healthy beagles

The aim of this study was to evaluate the safety and anti-obesity effects of the Korean red ginseng extract in dogs. To this end, we fed healthy beagles a Korean red ginseng diet and/or snack for 8 weeks. The dogs were submitted to a thorough physical examination, complete blood count, serum biochemistry analysis, analysis of adipose tissue activity, and body fat-content analysis by computed tomography (CT). At the end of the study period, the dogs that were fed the ginseng extract-diet/snack showed a significant decrease in body weight, body condition score and leptin levels relative to the baseline value. The CT findings revealed a decrease in body fat content in dogs fed the ginseng extract diet but not in those fed the ginseng-extract snack. The results of blood analysis did not show any meaningful changes in any of the dogs. All dogs tolerated the diet/snack well, and there were no adverse events. Our results suggest that the Korean red ginseng extract diet can potentially serve as an anti-obesity diet for reducing fat mass in dogs.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Metabolite-Sensing Receptor Ffar2 Regulates Colonic Group 3 Innate Lymphoid Cells and Gut Immunity

Group 3 innate lymphoid cells (ILC3s) sense environmental signals that are critical for gut homeostasis and host defense. However, the metabolite-sensing G-protein-coupled receptors that regulate colonic ILC3s remain poorly understood. We found that colonic ILC3s expressed Ffar2, a microbial metabolite-sensing receptor, and that Ffar2 agonism promoted ILC3 expansion and function. Deficiency of Ffar2 in ILC3s decreased their in situ proliferation and ILC3-derived interleukin-22 (IL-22) production. This led to impaired gut epithelial function characterized by altered mucus-associated proteins and antimicrobial peptides and increased susceptibility to colonic injury and bacterial infection. Ffar2 increased IL-22⁺ CCR6⁺ ILC3s and influenced ILC3 abundance in colonic lymphoid tissues. Ffar2 agonism differentially activated AKT or ERK signaling and increased ILC3-derived IL-22 via an AKT and STAT3 axis. Our findings suggest that Ffar2 regulates colonic ILC3 proliferation and function, and they identify an ILC3-receptor signaling pathway modulating gut homeostasis and pathogen defense.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Properties Investigation of GO/HA/Pt Composite Thin Film

Hydroxyapatite/graphene oxide/platinum (HA/GO/Pt) nanocomposite was synthesized and electrodeposited on a pure zirconium substrate. The coated zirconium was annealed at 200, 300, 400, and 600°C in vacuum furnace in presence of argon gas. The structure and morphology of the coated samples were characterized. Biocompatibility and wear and corrosion resistances of specimens were examined. The result of corrosion tests shows that the graphene into HA/Pt composites significantly improves their corrosion resistance. The wear tests results of uncoated and coated samples before and after annealing show that coated samples annealed at 300°C had better wear resistance compared with uncoated and coated samples at other temperatures. Furthermore, the biocompatibility test shows that the coatings improved the cell attachment and proliferation compared to the pure zirconium substrate.

Tracking short-term changes in the genetic diversity and antimicrobial resistance of OXA-232-producing Klebsiella pneumoniae ST14 in clinical settings

OBJECTIVES

To track stepwise changes in genetic diversity and antimicrobial resistance in rapidly evolving OXA-232-producing Klebsiella pneumoniae ST14, an emerging carbapenem-resistant high-risk clone, in clinical settings.

METHODS

Twenty-six K. pneumoniae ST14 isolates were collected by the Korean Nationwide Surveillance of Antimicrobial Resistance system over the course of 1 year. Isolates were subjected to whole-genome sequencing and MIC determinations using 33 antibiotics from 14 classes.

RESULTS

Single-nucleotide polymorphism (SNP) typing identified 72 unique SNP sites spanning the chromosomes of the isolates, dividing them into three clusters (I, II and III). The initial isolate possessed two plasmids with 18 antibiotic-resistance genes, including bla_OXA-232, and exhibited resistance to 11 antibiotic classes. Four other plasmids containing 12 different resistance genes, including bla_CTX-M-15 and strA/B, were introduced over time, providing additional resistance to aztreonam and streptomycin. Moreover, chromosomal integration of insertion sequence Ecp1-bla_CTX-M-15 mediated the inactivation of mgrB responsible for colistin resistance in four isolates from cluster III. To the best of our knowledge, this is the first description of K. pneumoniae ST14 resistant to both carbapenem and colistin in South Korea. Furthermore, although some acquired genes were lost over time, the retention of 12 resistance genes and inactivation of mgrB provided resistance to 13 classes of antibiotics.

CONCLUSIONS

We describe stepwise changes in OXA-232-producing K. pneumoniae ST14 in vivo over time in terms of antimicrobial resistance. Our findings contribute to our understanding of the evolution of emerging high-risk K. pneumoniae clones and provide reference data for future outbreaks.