Antibiotic Dosing in Chronic Kidney Disease

Infectious process is an important cause of morbidity and mortality among patients with chronic kidney disease. Prescription of antibacterial drugs should take into account the pharmacokinetic parameters of the medicine and the individual characteristics of the patient. Adequate antibiotic dosing is crucial for positive treatment outcome and minimisation of side effects. The aim of the study was to analyse scientific literature on factors affecting the dosing of antibacterials in patients with chronic kidney disease. Since most antibacterial medicines are eliminated by the kidneys, a decrease in glomerular filtration rate or kidney function should be followed by the dose adjustment in order to prevent the medicine accumulation and reduce the risk of side effects. Antibiotic dosing in such patients should be accompanied by kidney function assessment and be adjusted to ensure effective and safe treatment, as well as prevention of bacterial resistance. The review provides data on the dosing of some antibiotic groups (beta-lactams, aminoglycosides, fluoroquinolones) at different creatinine clearance rates. Extrarenal excretion of medicines does not usually require the dose adjustment in patients with chronic kidney disease

Ephemeris refinement of 21 Hot Jupiter exoplanets with high timing uncertainties

Transit events of extrasolar planets offer a wealth of information for planetary characterization. However, for many known targets, the uncertainty of their predicted transit windows prohibits an accurate scheduling of follow-up observations. In this work, we refine the ephemerides of 21 Hot Jupiter exoplanets with the largest timing uncertainty. We collected 120 professional and amateur transit light curves of the targets of interest, observed with 0.3m to 2.2m telescopes, and analyzed them including the timing information of the planets discovery papers. In the case of WASP-117b, we measured a timing deviation compared to the known ephemeris of about 3.5 hours, for HAT-P-29b and HAT-P-31b the deviation amounted to about 2 hours and more. For all targets, the new ephemeris predicts transit timings with uncertainties of less than 6 minutes in the year 2018 and less than 13 minutes until 2025. Thus, our results allow for an accurate scheduling of follow-up observations in the next decade

Transit timing analysis of the exoplanet TrES-5 b. Possible existence of the exoplanet TrES-5 c

peer reviewedIn this work, we present transit timing variations detected for the exoplanet TrES-5b. To obtain the necessary amount of photometric data for this exoplanet, we have organized an international campaign to search for exoplanets based on the transit-timing variation (TTV) method and as a result of this we collected 30 new light curves, 15 light curves from the Exoplanet Transit Database (ETD) and 8 light curves from the literature for the timing analysis of the exoplanet TrES-5b. We have detected timing variations with a semi-amplitude of A≈ 0.0016 d and a period of P≈ 99 d. We carried out the N-body modelling based on the three-body problem. The detected perturbation of TrES-5b may be caused by a second exoplanet in the TrES-5 system. We have calculated the possible mass and resonance of the object: M ≈ 0.24MJup at a 1:2 Resonance. © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.RSF: 14-50-0004

Discovery of a young low-mass brown dwarf transiting a fast-rotating F-type star by the Galactic Plane eXoplanet (GPX) survey

We announce the discovery of GPX-1 b, a transiting brown dwarf with a mass of $19.7\pm 1.6$ $M_{\mathrm{Jup}}$ and a radius of $1.47\pm0.10$ $R_{\mathrm{Jup}}$, the first sub-stellar object discovered by the Galactic Plane eXoplanet (GPX) survey. The brown dwarf transits a moderately bright ($V$ = 12.3 mag) fast-rotating F-type star with a projected rotational velocity $v\sin{ i_*}=40\pm10$ km/s. We use the isochrone placement algorithm to characterize the host star, which has effective temperature $7000\pm200$ K, mass $1.68\pm0.10$ $M_{\mathrm{Sun}}$, radius $1.56\pm0.10$ $R_{\mathrm{Sun}}$ and approximate age $0.27_{-0.15}^{+0.09}$ Gyr. GPX-1 b has an orbital period of $\sim$1.75 d, and a transit depth of $0.90\pm0.03$ %. We describe the GPX transit detection observations, subsequent photometric and speckle-interferometric follow-up observations, and SOPHIE spectroscopic measurements, which allowed us to establish the presence of a sub-stellar object around the host star. GPX-1 was observed at 30-min integrations by TESS in Sector 18, but the data is affected by blending with a 3.4 mag brighter star 42 arcsec away. GPX-1 b is one of about two dozen transiting brown dwarfs known to date, with a mass close to the theoretical brown dwarf/gas giant planet mass transition boundary. Since GPX-1 is a moderately bright and fast-rotating star, it can be followed-up by the means of Doppler tomography.Comment: 13 pages, 13 figures, accepted to MNRAS in May 202

Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004–2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions

Особенности дозирования антибиотиков при хронической болезни почек

Infectious process is an important cause of morbidity and mortality among patients with chronic kidney disease. Prescription of antibacterial drugs should take into account the pharmacokinetic parameters of the medicine and the individual characteristics of the patient. Adequate antibiotic dosing is crucial for positive treatment outcome and minimisation of side effects. The aim of the study was to analyse scientific literature on factors affecting the dosing of antibacterials in patients with chronic kidney disease. Since most antibacterial medicines are eliminated by the kidneys, a decrease in glomerular filtration rate or kidney function should be followed by the dose adjustment in order to prevent the medicine accumulation and reduce the risk of side effects. Antibiotic dosing in such patients should be accompanied by kidney function assessment and be adjusted to ensure effective and safe treatment, as well as prevention of bacterial resistance. The review provides data on the dosing of some antibiotic groups (beta-lactams, aminoglycosides, fluoroquinolones) at different creatinine clearance rates. Extrarenal excretion of medicines does not usually require the dose adjustment in patients with chronic kidney disease.Инфекционный процесс является важной причиной заболеваемости и смертности среди пациентов с хронической болезнью почек. При назначении антибактериальных препаратов необходимо учитывать фармакокинетические параметры препарата и индивидуальные особенности пациента. Обязательным условием достижения положительных результатов лечения при минимизации побочных эффектов является корректное дозирование антибиотиков. Цель работы – анализ данных литературы о факторах, влияющих на дозирование антибактериальных препаратов у пациентов с хронической болезнью почек. Поскольку большинство антибактериальных препаратов элиминируется почками, при снижении скорости клубочковой фильтрации или функции почек необходимо корректировать дозу, чтобы предотвратить кумуляцию препарата и уменьшить риск развития побочных эффектов. Дозирование антибактериальных препаратов у таких пациентов должно сопровождаться оценкой функции почек и быть сбалансировано с необходимостью обеспечения эффективного и безопасного лечения, а также предотвращения бактериальной резистентности. В обзоре приведены данные о дозировании конкретных групп антибиотиков (бета-лактамов, аминогликозидов, фторхинолонов) при различных показателях клиренса креатинина. При внепочечном пути выведения лекарственного препарата из организма коррекция дозы при хронической болезни почек, как правило, не требуется

Discovery of a Young Low-Mass Brown Dwarf Transiting a Fast-Rotating F-Type Star by the Galactic Plane eXoplanet (GPX) Survey

We announce the discovery of GPX-1 b, a transiting brown dwarf with a mass of 19.7 ± 1.6 MJup and a radius of 1.47 ± 0.10 RJup, the first substellar object discovered by the Galactic Plane eXoplanet (GPX) survey. The brown dwarf transits a moderately bright (V = 12.3 mag) fast-rotating F-type star with a projected rotational velocity v sin i∗ = 40 ± 10 km s−1. We use the isochrone placement algorithm to characterize the host star, which has effective temperature 7000 ± 200 K, mass 1.68 ± 0.10 M☉, radius 1.56 ± 0.10 R☉, and approximate age 0.27-0.15+0.09 Gyr. GPX-1 b has an orbital period of -1.75 d and a transit depth of 0.90 ± 0.03 per cent. We describe the GPX transit detection observations, subsequent photometric and speckle-interferometric follow-up observations, and SOPHIE spectroscopic measurements, which allowed us to establish the presence of a substellar object around the host star. GPX-1 was observed at 30-min integrations by TESS in Sector 18, but the data are affected by blending with a 3.4 mag brighter star 42 arcsec away. GPX-1 b is one of about two dozen transiting brown dwarfs known to date, with a mass close to the theoretical brown dwarf/gas giant planet mass transition boundary. Since GPX-1 is a moderately bright and fast-rotating star, it can be followed-up by the means of the Doppler tomography. © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society.The authors would like to thank the anonymous reviewer for their time and attention. The constructive comments we received helped us to improve the quality of the paper. This research has made use of the Exoplanet Orbit Database, the Exoplanet Data Explorer at exoplanets.org, Extrasolar Planets Encyclopaedia at exoplanets.eu, and the NASA Exoplanet Archive, which is operated by the California Institute of Technology under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research was made possible through the use of the AAVSO Photometric All-Sky Survey (APASS), funded by the Robert Martin Ayers Sciences Fund and NSF AST-1412587. This research made use of Aladin (Bonnarel et al. 2000). IRAF is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. This research made use of ASTROPY,3 a community-developed core PYTHON package for Astronomy (Astropy Collaboration 2013; Price-Whelan et al. 2018). We acknowledge the use of TESScut.MAST data from full frame time series images (FFI) collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA?s Science Mission directorate. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. PB thanks Bruce Gary, the XO survey, and the KELT survey for furthering his education in exoplanet research. AYB would like to thank Catarina Fernandes and Julien de Wit for helpful discussions about the system. Organization of the EXPANSION project (ES), follow-up campaign of the photometry observations, speckle-interferometry observations with 6-m telescope BTA were supported by the Russian Science Foundation grant 19-72-10023. The work of VK was supported by the Ministry of Science and Higher Education of the Russian Federation, topic no. FEUZ-0836-2020-0038. This work was partly supported by the Ministry of Science and High Education of the Russian Federation (project no. FZZE-2020-0024) and Irkutsk State University (project no. 111-14-306). This work was partially supported by the Ministry of Science and Higher Education of the Russian Federation (project nos. FEUZ-2020-0030 and 075-15-2020-780). TRAPPIST-North is a project funded by the University of Liege, in collaboration with Cadi Ayyad University of Marrakech (Morocco). EJ and MG are F.R.S.-FNRS Senior Research Associates. The research leading to these results has received funding from the ARC grant for Concerted Research Actions financed by the Federation Wallonia-Brussels and from the International Balzan Prize Foundation. TRAPPIST is funded by the Belgian National Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant FRFC 2.5.594.09.F. EP acknowledges the Europlanet 2024 RI project funded by the European Union?s Horizon 2020 Framework Programme (grant agreement no. 871149). AB acknowledge the support from the Program of Development of Lomonosov Moscow State University (Leading Scientific School ’Physics of stars, relativistic objects and galaxies’). OB thanks TÜBİTAK National Observatory for a partial support in using the T100 telescope with the project number 19AT100-1346. ODSD is supported by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT) in the form of a work contract (DL 57/2016/CP1364/CT0004), institutional funds UIDB/04434/2020 and UIDP/04434/2020, and scientific projects funds PTDC/FIS-AST/28953/2017 and POCI-01-0145-FEDER-028953