93 research outputs found
Direct detection of extended-spectrum beta-lactamases (CTX-M) from blood cultures by LC-MS/MS bottom-up proteomics
Rapid bacterial species identification and antibiotic susceptibility testing in positive blood cultures have an important impact on the antibiotic treatment for patients. To identify extended-spectrum beta-lactamases (ESBL) directly in positive blood culture bottles, we developed a workflow of saponin extraction followed by a bottom-up proteomics approach using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The workflow was applied to positive blood cultures with Escherichia coli and Klebsiella pneumoniae collected prospectively in two academic hospitals over a 4-month period. Of 170 positive blood cultures, 22 (12.9%) contained ESBL-positive isolates based on standard susceptibility testing. Proteomic analysis identified CTX-M ESBLs in 95% of these isolates directly in positive blood cultures, whereas no false positives were found in the non-ESBL producing positive blood cultures. The results were confirmed by molecular characterisation of beta-lactamase genes. Based on this proof-of-concept study, we conclude that LC-MS/MS-based protein analysis can directly identify extended-spectrum beta lactamases in E. coli and K. pneumoniae positive blood cultures, and could be further developed for application in routine diagnostics
Personalized surveillance and aftercare for non-metastasized breast cancer:the NABOR study protocol of a multiple interrupted time series design
Background: Follow-up of curatively treated primary breast cancer patients consists of surveillance and aftercare and is currently mostly the same for all patients. A more personalized approach, based on patientsâ individual risk of recurrence and personal needs and preferences, may reduce patient burden and reduce (healthcare) costs. The NABOR study will examine the (cost-)effectiveness of personalized surveillance (PSP) and personalized aftercare plans (PAP) on patient-reported cancer worry, self-rated and overall quality of life and (cost-)effectiveness.Methods: A prospective multicenter multiple interrupted time series (MITs) design is being used. In this design, 10 participating hospitals will be observed for a period of eighteen months, while they -stepwise- will transit from care as usual to PSPs and PAPs. The PSP contains decisions on the surveillance trajectory based on individual risks and needs, assessed with the âBreast Cancer Surveillance Decision Aidâ including the INFLUENCE prediction tool. The PAP contains decisions on the aftercare trajectory based on individual needs and preferences and available care resources, which decision-making is supported by a patient decision aid. Patients are non-metastasized female primary breast cancer patients (N = 1040) who are curatively treated and start follow-up care. Patient reported outcomes will be measured at five points in time during two years of follow-up care (starting about one year after treatment and every six months thereafter). In addition, data on diagnostics and hospital visits from patientsâ Electronical Health Records (EHR) will be gathered. Primary outcomes are patient-reported cancer worry (Cancer Worry Scale) and overall quality of life (as assessed with EQ-VAS score). Secondary outcomes include health care costs and resource use, health-related quality of life (as measured with EQ5D-5L/SF-12/EORTC-QLQ-C30), risk perception, shared decision-making, patient satisfaction, societal participation, and cost-effectiveness. Next, the uptake and appreciation of personalized plans and patientsâ experiences of their decision-making process will be evaluated. Discussion: This study will contribute to insight in the (cost-)effectiveness of personalized follow-up care and contributes to development of uniform evidence-based guidelines, stimulating sustainable implementation of personalized surveillance and aftercare plans. Trial registration: Study sponsor: ZonMw. Retrospectively registered at ClinicalTrials.gov (2023), ID: NCT05975437.</p
Evolution of naturally occurring 5' non-translated region variants of hepatitis C virus genotype 1b in selectable replicons
Quasispecies shifts are essential for the development of persistent hepatitis C virus (HCV) infection. Naturally occurring sequence variations in the 5' non-translated region (NTR) of the virus could lead to changes in protein expression levels, reflecting selective forces on the virus. The extreme 5' end of the virus' genome, containing signals essential for replication, is followed by an internal ribosomal entry site (IRES) essential for protein translation as well as replication. The 5' NTR is highly conserved and has a complex RNA secondary structure consisting of several stem-loops. This report analyses the quasispecies distribution of the 5' NTR of an HCV genotype 1b clinical isolate and found a number of sequences differing from the consensus sequence. The consensus sequence, as well as a major variant located in stem-loop IIIa of the IRES, was investigated using self-replicating HCV RNA molecules in human hepatoma cells. The stem-loop IIIa mutation, which is predicted to disrupt the stem structure, showed slightly lower translation efficiency but was severely impaired in the colony formation of selectable HCV replicons. Interestingly, during selection of colonies supporting autonomous replication, mutations emerged that restored the base pairing in the stem-loop. Recloning of these altered IRESs confirmed that these second site revertants were more efficient in colony formation. In conclusion, naturally occurring variants in the HCV 5' NTR can lead to changes in their replication ability. Furthermore, IRES quasispecies evolution was observed in vitro under the selective pressure of the replicon system
Dietary trehalose enhances virulence of epidemic Clostridium difficile
Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc
Proteomic identification of Axc, a novel beta-lactamase with carbapenemase activity in a meropenem-resistant clinical isolate of Achromobacter xylosoxidans
Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc
Near-infrared fluorescence imaging compared to standard sentinel lymph node detection with blue dye in patients with vulvar cancer â a randomized controlled trial
Objective. The aim of this study was to assess the superiority of ICG-99mTc-nanocolloid for the intraoperative
visual detection of sentinel lymph nodes (SLNs) in vulvar squamous cell carcinoma (VSCC) patients compared to
standard SLN detection using 99mTc-nanocolloid with blue dye.
Methods. In this multicenter, randomized controlled trial, VSCC patients underwent either the standard SLN
procedure or with the hybrid tracer ICG-99mTc-nanocolloid. The primary endpoint was the percentage of fluorescent SLNs compared to blue SLNs. Secondary endpoints were successful SLN procedures, surgical outcomes and
postoperative complications.
Results. Forty-eight patients were randomized to the standard (n = 24) or fluorescence imaging group
(n = 24) using ICG-99mTc-nanocolloid. The percentage of blue SLNs was 65.3% compared to 92.5% fluorescent
SLNs (p < 0.001). A successful SLN procedure was obtained in 92.1% of the groins in the standard group and
97.2% of the groins in the fluorescence imaging group (p = 0.33). Groups did not differ in surgical outcome,
although more short-term postoperative complications were documented in the standard group (p = 0.041).
Conclusions. Intraoperative visual detection of SLNs in patients with VSCC using ICG-99mTc-nanocolloid was
superior compared to 99mTc-nanocolloid and blue dye. The rate of successful SLN procedures between both
groups was not significantly different. Fluorescence imaging has potential to be used routinely in the SLN procedure in VSCC patients to facilitate the search by direct visualizatio
Sensitivity of grapevine phenology to water availability, temperature and CO2 concentration
In recent decades, mean global temperatures have increased in parallel with a sharp rise in atmospheric carbon dioxide (CO2) levels, with apparent implications for precipitation patterns. The aim of the present work is to assess the sensitivity of different phenological stages of grapevine to temperature and to study the influence of other factors related to climate change (water availability and CO2 concentration) on this relationship. Grapevine phenological records from 9 plantings between 42.75°N and 46.03°N consisting of dates for budburst, flowering and fruit maturity were used. In addition, we used phenological data collected from 2 years of experiments with grapevine fruit-bearing cuttings with two grapevine varieties under two levels of water availability, two temperature regimes and two levels of CO2. Dormancy breaking and flowering were strongly dependent on spring temperature, while neither variation in temperature during the chilling period nor precipitation significantly affected budburst date. The time needed to reach fruit maturity diminished with increasing temperature and decreasing precipitation. Experiments under semi-controlled conditions revealed great sensitivity of berry development to both temperature and CO2. Water availability had significant interactions with both temperature and CO2; however, in general, water deficit delayed maturity when combined with other factors. Sensitivities to temperature and CO2 varied widely, but higher sensitivities appeared in the coolest year, particularly for the late ripening variety, âWhite Tempranilloâ. The knowledge gained in whole plant physiology and multi stress approaches is crucial to predict the effects of climate change and to design mitigation and adaptation strategies allowing viticulture to cope with climate change
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Pion interferometry in Au+Au collisions at sqrt[sNN]=200GeV
We present a systematic analysis of two-pion interferometry in Au+Au collisions at sqrt[sNN]=200GeV using the STAR detector at Relativistic Heavy Ion Collider. We extract the Hanbury-Brown and Twiss radii and study their multiplicity, transverse momentum, and azimuthal angle dependence. The Gaussianness of the correlation function is studied. Estimates of the geometrical and dynamical structure of the freeze-out source are extracted by fits with blast-wave parametrizations. The expansion of the source and its relation with the initial energy density distribution is studied
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