115 research outputs found
Urethral Catheter Biofilms Reveal Plasticity in Bacterial Composition and Metabolism and Withstand Host Immune Defenses in Hypoxic Environment
Biofilms composed of multiple microorganisms colonize the surfaces of indwelling urethral catheters that are used serially by neurogenic bladder patients and cause chronic infections. Well-adapted pathogens in this niche are Escherichia coli, Proteus, and Enterococcus spp., species that cycle through adhesion and multilayered cell growth, trigger host immune responses, are starved off nutrients, and then disperse. Viable microbial foci retained in the urinary tract recolonize catheter surfaces. The molecular adaptations of bacteria in catheter biofilms (CBs) are not well-understood, promising new insights into this pathology based on host and microbial meta-omics analyses from clinical specimens. We examined catheters from nine neurogenic bladder patients longitudinally over up to 6 months. Taxonomic analyses from 16S rRNA gene sequencing and liquid chromatographyâtandem mass spectrometry (LC-MS/MS)âbased proteomics revealed that 95% of all catheter and corresponding urinary pellet (UP) samples contained bacteria. CB biomasses were dominated by Enterobacteriaceae spp. and often accompanied by lactic acid and anaerobic bacteria. Systemic antibiotic drug treatments of patients resulted in either transient or lasting microbial community perturbations. Neutrophil effector proteins were abundant not only in UP but also CB samples, indicating their penetration of biofilm surfaces. In the context of one patient who advanced to a kidney infection, Proteus mirabilis proteomic data suggested a combination of factors associated with this disease complication: CB biomasses were high; the bacteria produced urease alkalinizing the pH and triggering urinary salt deposition on luminal catheter surfaces; P. mirabilis utilized energy-producing respiratory systems more than in CBs from other patients. The NADH:quinone oxidoreductase II (Nqr), a Na+ translocating enzyme not operating as a proton pump, and the nitrate reductase A (Nar) equipped the pathogen with electron transport chains promoting growth under hypoxic conditions. Both P. mirabilis and E. coli featured repertoires of transition metal ion acquisition systems in response to human host-mediated iron and zinc sequestration. We discovered a new drug target, the Nqr respiratory system, whose deactivation may compromise P. mirabilis growth in a basic pH milieu. Animal models would not allow such molecular-level insights into polymicrobial biofilm metabolism and interactions because the complexity cannot be replicated
Prospective Association of Daily Steps with Cardiovascular Disease: A Harmonized Meta-Analysis
Background:
Taking fewer than the widely promoted â10â000 steps per dayâ has recently been associated with lower risk of all-cause mortality. The relationship of steps and cardiovascular disease (CVD) risk remains poorly described. A meta-analysis examining the doseâresponse relationship between steps per day and CVD can help inform clinical and public health guidelines.
Methods:
Eight prospective studies (20â152 adults [ie, â„18 years of age]) were included with device-measured steps and participants followed for CVD events. Studies quantified steps per day and CVD events were defined as fatal and nonfatal coronary heart disease, stroke, and heart failure. Cox proportional hazards regression analyses were completed using study-specific quartiles and hazard ratios (HR) and 95% CI were meta-analyzed with inverse-varianceâweighted random effects models.
Results:
The mean age of participants was 63.2±12.4 years and 52% were women. The mean follow-up was 6.2 years (123â209 person-years), with a total of 1523 CVD events (12.4 per 1000 participant-years) reported. There was a significant difference in the association of steps per day and CVD between older (ie, â„60 years of age) and younger adults (ie, <60 years of age). For older adults, the HR for quartile 2 was 0.80 (95% CI, 0.69 to 0.93), 0.62 for quartile 3 (95% CI, 0.52 to 0.74), and 0.51 for quartile 4 (95% CI, 0.41 to 0.63) compared with the lowest quartile. For younger adults, the HR for quartile 2 was 0.79 (95% CI, 0.46 to 1.35), 0.90 for quartile 3 (95% CI, 0.64 to 1.25), and 0.95 for quartile 4 (95% CI, 0.61 to 1.48) compared with the lowest quartile. Restricted cubic splines demonstrated a nonlinear association whereby more steps were associated with decreased risk of CVD among older adults.
Conclusions:
For older adults, taking more daily steps was associated with a progressively decreased risk of CVD. Monitoring and promoting steps per day is a simple metric for clinicianâpatient communication and population health to reduce the risk of CVD
Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts
Background Although 10000 steps per day is widely promoted to have health benefits, there is little evidence to support
this recommendation. We aimed to determine the association between number of steps per day and stepping rate
with all-cause mortality.
Methods In this meta-analysis, we identified studies investigating the effect of daily step count on all-cause mortality
in adults (aged â„18 years), via a previously published systematic review and expert knowledge of the field. We asked
participating study investigators to process their participant-level data following a standardised protocol. The primary
outcome was all-cause mortality collected from death certificates and country registries. We analysed the doseâ
response association of steps per day and stepping rate with all-cause mortality. We did Cox proportional hazards
regression analyses using study-specific quartiles of steps per day and calculated hazard ratios (HRs) with inversevariance weighted random effects models.
Findings We identified 15 studies, of which seven were published and eight were unpublished, with study start dates
between 1999 and 2018. The total sample included 47 471 adults, among whom there were 3013 deaths (10·1 per
1000 participant-years) over a median follow-up of 7·1 years ([IQR 4·3â9·9]; total sum of follow-up across studies was
297 837 person-years). Quartile median steps per day were 3553 for quartile 1, 5801 for quartile 2, 7842 for quartile 3,
and 10 901 for quartile 4. Compared with the lowest quartile, the adjusted HR for all-cause mortality was 0·60 (95% CI
0·51â0·71) for quartile 2, 0·55 (0·49â0·62) for quartile 3, and 0·47 (0·39â0·57) for quartile 4. Restricted cubic splines
showed progressively decreasing risk of mortality among adults aged 60 years and older with increasing number of
steps per day until 6000â8000 steps per day and among adults younger than 60 years until 8000â10000 steps per day.
Adjusting for number of steps per day, comparing quartile 1 with quartile 4, the association between higher stepping
rates and mortality was attenuated but remained significant for a peak of 30 min (HR 0·67 [95% CI 0·56â0·83]) and
a peak of 60 min (0·67 [0·50â0·90]), but not significant for time (min per day) spent walking at 40 steps per min or
faster (1·12 [0·96â1·32]) and 100 steps per min or faster (0·86 [0·58â1·28]).
Interpretation Taking more steps per day was associated with a progressively lower risk of all-cause mortality, up to a
level that varied by age. The findings from this meta-analysis can be used to inform step guidelines for public health
promotion of physical activity
Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts
Background
Although 10â000 steps per day is widely promoted to have health benefits, there is little evidence to support this recommendation. We aimed to determine the association between number of steps per day and stepping rate with all-cause mortality.
Methods
In this meta-analysis, we identified studies investigating the effect of daily step count on all-cause mortality in adults (aged â„18 years), via a previously published systematic review and expert knowledge of the field. We asked participating study investigators to process their participant-level data following a standardised protocol. The primary outcome was all-cause mortality collected from death certificates and country registries. We analysed the doseâresponse association of steps per day and stepping rate with all-cause mortality. We did Cox proportional hazards regression analyses using study-specific quartiles of steps per day and calculated hazard ratios (HRs) with inverse-variance weighted random effects models.
Findings
We identified 15 studies, of which seven were published and eight were unpublished, with study start dates between 1999 and 2018. The total sample included 47â471 adults, among whom there were 3013 deaths (10·1 per 1000 participant-years) over a median follow-up of 7·1 years ([IQR 4·3â9·9]; total sum of follow-up across studies was 297â837 person-years). Quartile median steps per day were 3553 for quartile 1, 5801 for quartile 2, 7842 for quartile 3, and 10â901 for quartile 4. Compared with the lowest quartile, the adjusted HR for all-cause mortality was 0·60 (95% CI 0·51â0·71) for quartile 2, 0·55 (0·49â0·62) for quartile 3, and 0·47 (0·39â0·57) for quartile 4. Restricted cubic splines showed progressively decreasing risk of mortality among adults aged 60 years and older with increasing number of steps per day until 6000â8000 steps per day and among adults younger than 60 years until 8000â10â000 steps per day. Adjusting for number of steps per day, comparing quartile 1 with quartile 4, the association between higher stepping rates and mortality was attenuated but remained significant for a peak of 30 min (HR 0·67 [95% CI 0·56â0·83]) and a peak of 60 min (0·67 [0·50â0·90]), but not significant for time (min per day) spent walking at 40 steps per min or faster (1·12 [0·96â1·32]) and 100 steps per min or faster (0·86 [0·58â1·28]).
Interpretation
Taking more steps per day was associated with a progressively lower risk of all-cause mortality, up to a level that varied by age. The findings from this meta-analysis can be used to inform step guidelines for public health promotion of physical activity.
Funding
US Centers for Disease Control and Prevention
Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube neutrino telescope
We report in detail on searches for eV-scale sterile neutrinos, in the
context of a 3+1 model, using eight years of data from the IceCube neutrino
telescope. By analyzing the reconstructed energies and zenith angles of 305,735
atmospheric and events we construct confidence
intervals in two analysis spaces: vs.
under the conservative assumption ; and
vs. given sufficiently large that
fast oscillation features are unresolvable. Detailed discussions of the event
selection, systematic uncertainties, and fitting procedures are presented. No
strong evidence for sterile neutrinos is found, and the best-fit likelihood is
consistent with the no sterile neutrino hypothesis with a p-value of 8\% in the
first analysis space and 19\% in the second.Comment: This long-form paper is a companion to the letter "An eV-scale
sterile neutrino search using eight years of atmospheric muon neutrino data
from the IceCube Neutrino Observatory". v2: update other experiments contours
on results plo
An eV-scale sterile neutrino search using eight years of atmospheric muon neutrino data from the IceCube Neutrino Observatory
The results of a 3+1 sterile neutrino search using eight years of data from
the IceCube Neutrino Observatory are presented. A total of 305,735 muon
neutrino events are analyzed in reconstructed energy-zenith space to test for
signatures of a matter-enhanced oscillation that would occur given a sterile
neutrino state with a mass-squared differences between 0.01\,eV and
100\,eV. The best-fit point is found to be at
and , which is consistent with the no sterile
neutrino hypothesis with a p-value of 8.0\%.Comment: 11 pages, 5 figures. This letter is supported by the long-form paper
"Searching for eV-scale sterile neutrinos with eight years of atmospheric
neutrinos at the IceCube neutrino telescope," also appearing on arXiv.
Digital data release available at:
https://github.com/icecube/HE-Sterile-8year-data-releas
LeptonInjector and LeptonWeighter: A neutrino event generator and weighter for neutrino observatories
We present a high-energy neutrino event generator, called LeptonInjector,
alongside an event weighter, called LeptonWeighter. Both are designed for
large-volume Cherenkov neutrino telescopes such as IceCube. The neutrino event
generator allows for quick and flexible simulation of neutrino events within
and around the detector volume, and implements the leading Standard Model
neutrino interaction processes relevant for neutrino observatories:
neutrino-nucleon deep-inelastic scattering and neutrino-electron annihilation.
In this paper, we discuss the event generation algorithm, the weighting
algorithm, and the main functions of the publicly available code, with
examples.Comment: 28 pages, 10 figures, 3 table
Measurement of the high-energy all-flavor neutrino-nucleon cross section with IceCube
The flux of high-energy neutrinos passing through the Earth is attenuated due to their interactions with matter. The interaction rate is determined by the neutrino interaction cross section and affects the flux arriving at the IceCube Neutrino Observatory, a cubic-kilometer neutrino detector embedded in the Antarctic ice sheet. We present a measurement of the neutrino cross section between 60 TeV and 10 PeV using the high-energy starting event (HESE) sample from IceCube with 7.5 years of data. The result is binned in neutrino energy and obtained using both Bayesian and frequentist statistics. We find it compatible with predictions from the Standard Model. While the cross section is expected to be flavor independent above 1 TeV, additional constraints on the measurement are included through updated experimental particle identification (PID) classifiers, proxies for the three neutrino flavors. This is the first such measurement to use a ternary PID observable and the first to account for neutrinos from tau decay
The FANCM:p.Arg658* truncating variant is associated with risk of triple-negative breast cancer
Abstract: Breast cancer is a common disease partially caused by genetic risk factors. Germline pathogenic variants in DNA repair genes BRCA1, BRCA2, PALB2, ATM, and CHEK2 are associated with breast cancer risk. FANCM, which encodes for a DNA translocase, has been proposed as a breast cancer predisposition gene, with greater effects for the ER-negative and triple-negative breast cancer (TNBC) subtypes. We tested the three recurrent protein-truncating variants FANCM:p.Arg658*, p.Gln1701*, and p.Arg1931* for association with breast cancer risk in 67,112 cases, 53,766 controls, and 26,662 carriers of pathogenic variants of BRCA1 or BRCA2. These three variants were also studied functionally by measuring survival and chromosome fragility in FANCMâ/â patient-derived immortalized fibroblasts treated with diepoxybutane or olaparib. We observed that FANCM:p.Arg658* was associated with increased risk of ER-negative disease and TNBC (OR = 2.44, P = 0.034 and OR = 3.79; P = 0.009, respectively). In a country-restricted analysis, we confirmed the associations detected for FANCM:p.Arg658* and found that also FANCM:p.Arg1931* was associated with ER-negative breast cancer risk (OR = 1.96; P = 0.006). The functional results indicated that all three variants were deleterious affecting cell survival and chromosome stability with FANCM:p.Arg658* causing more severe phenotypes. In conclusion, we confirmed that the two rare FANCM deleterious variants p.Arg658* and p.Arg1931* are risk factors for ER-negative and TNBC subtypes. Overall our data suggest that the effect of truncating variants on breast cancer risk may depend on their position in the gene. Cell sensitivity to olaparib exposure, identifies a possible therapeutic option to treat FANCM-associated tumors
- âŠ