10 research outputs found
Detection of Legionellae in Hospital Water Samples by Quantitative Real-Time LightCycler PCR
Contamination of hospital water systems with legionellae is a well-known cause of nosocomial legionellosis. We describe a new real-time LightCycler PCR assay for quantitative determination of legionellae in potable water samples. Primers that amplify both a 386-bp fragment of the 16S rRNA gene from Legionella spp. and a specifically cloned fragment of the phage lambda, added to each sample as an internal inhibitor control, were used. The amplified products were detected by use of a dual-color hybridization probe assay design and quantified with external standards composed of Legionella pneumophila genomic DNA. The PCR assay had a sensitivity of 1 fg of Legionella DNA (i.e., less than one Legionella organism) per assay and detected 44 Legionella species and serogroups. Seventy-seven water samples from three hospitals were investigated by PCR and culture. The rates of detection of legionellae were 98.7% (76 of 77) by the PCR assay and 70.1% (54 of 77) by culture; PCR inhibitors were detected in one sample. The amounts of legionellae calculated from the PCR results were associated with the CFU detected by culture (r = 0.57; P < 0.001), but PCR results were mostly higher than the culture results. Since L. pneumophila is the main cause of legionellosis, we further developed a quantitative L. pneumophila-specific PCR assay targeting the macrophage infectivity potentiator (mip) gene, which codes for an immunophilin of the FK506 binding protein family. All but one of the 16S rRNA gene PCR-positive water samples were also positive in the mip gene PCR, and the results of the two PCR assays were correlated. In conclusion, the newly developed Legionella genus-specific and L. pneumophila species-specific PCR assays proved to be valuable tools for investigation of Legionella contamination in potable water systems
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Methods and results of a search for gravitational waves associated with gamma-ray bursts using the GEO 600, LIGO, and Virgo detectors
In this paper we report on a search for short-duration gravitational wave bursts in the frequency range 64 Hz–1792 Hz associated with gamma-ray bursts (GRBs), using data from GEO 600 and one of the LIGO or Virgo detectors. We introduce the method of a linear search grid to analyze GRB events with large sky localization uncertainties, for example the localizations provided by the Fermi Gamma-ray Burst Monitor (GBM). Coherent searches for gravitational waves (GWs) can be computationally intensive when the GRB sky position is not well localized, due to the corrections required for the difference in arrival time between detectors. Using a linear search grid we are able to reduce the computational cost of the analysis by a factor of O(10) for GBM events. Furthermore, we demonstrate that our analysis pipeline can improve upon the sky localization of GRBs detected by the GBM, if a high-frequency GW signal is observed in coincidence. We use the method of the linear grid in a search for GWs associated with 129 GRBs observed satellite-based gamma-ray experiments between 2006 and 2011. The GRBs in our sample had not been previously analyzed for GW counterparts. A fraction of our GRB events are analyzed using data from GEO 600 while the detector was using squeezed-light states to improve its sensitivity; this is the first search for GWs using data from a squeezed-light interferometric observatory. We find no evidence for GW signals, either with any individual GRB in this sample or with the population as a whole. For each GRB we place lower bounds on the distance to the progenitor, under an assumption of a fixed GW emission energy of 10−2M⊙c2, with a median exclusion distance of 0.8 Mpc for emission at 500 Hz and 0.3 Mpc at 1 kHz. The reduced computational cost associated with a linear search grid will enable rapid searches for GWs associated with Fermi GBM events once the advanced LIGO and Virgo detectors begin operation. © 2014 The American Physical Societ
An international expanded-access programme of Everolimus : Addressing safety and efficacy in patients with metastatic renal cell carcinoma who progress after initial vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapy
BACKGROUND AND OBJECTIVES: The RECORD-1 trial established the clinical benefit of everolimus in patients with metastatic renal cell carcinoma (mRCC) after failure of initial vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) therapy. The REACT (RAD001 Expanded Access Clinical Trial in RCC) study was initiated to address an unmet medical need by providing everolimus prior to commercial availability, and also to further assess the safety and efficacy of everolimus in patients with VEGFr-TKI-refractory mRCC. PATIENTS AND METHODS: REACT (Clinicaltrials.gov: NCT00655252) was a global, open-label, expanded-access programme in patients with mRCC who were intolerant of, or who had progressed on or after stopping treatment with, any available VEGFr-TKI therapy. Patients received everolimus 10mg once daily, with dose and schedule modifications allowed for toxicity. Patients were closely monitored for the development of serious and grades 3/4 adverse events (AEs). Response was assessed by RECIST every 3months for the first year and every 6months thereafter. RESULTS: A total of 1367 patients were enroled. Safety findings and tumour responses were consistent with those observed in RECORD-1, with no new safety issues identified. The most commonly reported serious AEs were dyspnoea (5.0%), pneumonia (4.7%) and anaemia (4.1%), and the most commonly reported grades 3/4 AEs were anaemia (13.4%), fatigue (6.7%) and dyspnoea (6.5%). Best overall response was stable disease in 51.6% and partial response in 1.7% of patients. Median everolimus treatment duration was 14weeks. CONCLUSION: Everolimus is well tolerated in patients with mRCC and demonstrates a favourable risk-benefit ratio
Erratum: “First Search for Gravitational Waves from Known Pulsars with Advanced LIGO” (2017, ApJ, 839, 12)
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GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo during the Second Part of the Third Observing Run
The third Gravitational-Wave Transient Catalog (GWTC-3) describes signals detected with Advanced LIGO and Advanced Virgo up to the end of their third observing run. Updating the previous GWTC-2.1, we present candidate gravitational waves from compact binary coalescences during the second half of the third observing run (O3b) between 1 November 2019, 15∶00 Coordinated Universal Time (UTC) and 27 March 2020, 17∶00 UTC. There are 35 compact binary coalescence candidates identified by at least one of our search algorithms with a probability of astrophysical origin p_{astro}>0.5. Of these, 18 were previously reported as low-latency public alerts, and 17 are reported here for the first time. Based upon estimates for the component masses, our O3b candidates with p_{astro}>0.5 are consistent with gravitational-wave signals from binary black holes or neutron-star–black-hole binaries, and we identify none from binary neutron stars. However, from the gravitational-wave data alone, we are not able to measure matter effects that distinguish whether the binary components are neutron stars or black holes. The range of inferred component masses is similar to that found with previous catalogs, but the O3b candidates include the first confident observations of neutron-star–black-hole binaries. Including the 35 candidates from O3b in addition to those from GWTC-2.1, GWTC-3 contains 90 candidates found by our analysis with p_{astro}>0.5 across the first three observing runs. These observations of compact binary coalescences present an unprecedented view of the properties of black holes and neutron stars