498 research outputs found

    Space research with intact organisms: The role of Space Station Freedom

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    The study of intact organisms has provided biologists with a good working knowledge of most of the common organisms that have evolved in the 1 g environment of Earth. Reasonably accurate predictions can be made about organismal responses to most stimuli on Earth. To extend this knowledge to life without gravity, we must have access to the space environment for prolonged periods. Space Station Freedom will provide a facility with which to begin this type of research. Spaceflight research to date has been limited to relatively short-term exposures that have been informative but incomplete. This paper provides a brief background of known changes that have occurred in intact organisms in the space environment and proposes the kinds of experiments that are needed to expand our knowledge of life on Earth and in space

    Outpatient antibiotic prescription trends in the United States: A national cohort study

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    OBJECTIVETo characterize trends in outpatient antibiotic prescriptions in the United StatesDESIGNRetrospective ecological and temporal trend study evaluating outpatient antibiotic prescriptions from 2013 to 2015SETTINGNational administrative claims data from a pharmacy benefits manager PARTICIPANTS. Prescription pharmacy beneficiaries from Express Scripts Holding CompanyMEASUREMENTSAnnual and seasonal percent change in antibiotic prescriptionsRESULTSApproximately 98 million outpatient antibiotic prescriptions were filled by 39 million insurance beneficiaries during the 3-year study period. The most commonly prescribed antibiotics were azithromycin, amoxicillin, amoxicillin/clavulanate, ciprofloxacin, and cephalexin. No significant changes in individual or overall annual antibiotic prescribing rates were found during the study period. Significant seasonal variation was observed, with antibiotics being 42% more likely to be prescribed during February than September (peak-to-trough ratio [PTTR], 1.42; 95% confidence interval [CI], 1.39–1.61). Similar seasonal trends were found for azithromycin (PTTR, 2.46; 95% CI, 2.44–3.47), amoxicillin (PTTR, 1.52; 95% CI, 1.42–1.89), and amoxicillin/clavulanate (PTTR, 1.78; 95% CI, 1.68–2.29).CONCLUSIONSThis study demonstrates that annual national outpatient antibiotic prescribing practices remained unchanged during our study period. Furthermore, seasonal peaks in antibiotics generally used to treat viral upper respiratory tract infections remained unchanged during cold and influenza season. These results suggest that inappropriate prescribing of antibiotics remains widespread, despite the concurrent release of several guideline-based best practices intended to reduce inappropriate antibiotic consumption; however, further research linking national outpatient antibiotic prescriptions to associated medical conditions is needed to confirm these findings.Infect Control Hosp Epidemiol 2018;39:584–589</jats:sec

    ‘Bouncing back’ from subclinical malaria:Inflammation and erythrocytosis after resolution of P. falciparum infection in Gambian children

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    Recent malaria is associated with an increased risk of systemic bacterial infection. The aetiology of this association is unclear but malaria-related haemolysis may be one contributory factor. To characterise the physiological consequences of persistent and recently resolved malaria infections and associated haemolysis, 1650 healthy Gambian children aged 8–15 years were screened for P. falciparum infection (by 18sRNA PCR) and/or anaemia (by haematocrit) at the end of the annual malaria transmission season (t1). P. falciparum-infected children and children with moderate or severe anaemia (haemoglobin concentration < 11g/dl) were age matched to healthy, uninfected, non-anaemic controls and screened again 2 months later (t2). Persistently infected children (PCR positive at t1 and t2) had stable parasite burdens and did not differ significantly haematologically or in terms of proinflammatory markers from healthy, uninfected children. However, among persistently infected children, IL-10 concentrations were positively correlated with parasite density suggesting a tolerogenic response to persistent infection. By contrast, children who naturally resolved their infections (positive at t1 and negative at t2) exhibited mild erythrocytosis and concentrations of pro-inflammatory markers were raised compared to other groups of children. These findings shed light on a ‘resetting’ and potential overshoot of the homeostatic haematological response following resolution of malaria infection. Interestingly, the majority of parameters tested were highly heterogeneous in uninfected children, suggesting that some may be harbouring cryptic malaria or other infections

    Bycatch weight, composition and preliminary estimates of the impact of bycatch reduction devices in Queensland's trawl fishery

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    This report provides quantitative information on the effects of turtle excluder devices (TEDs) and bycatch reduction devices (BRDs) on the catch rates of bycatch, prawns, scallops and byproduct species, such as Moreton Bay bugs and Balmain bugs, in Queensland’s major trawl fishing sectors. It also provides biological information on, and management advice for several species referred to in the Fishery Management Plan as the permitted species. Several recommendations are included for reducing bycatch in the trawl fishery and for sustaining stocks of the permitted species

    Limited morbidity and possible radiographic benefit of C2

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    Background: The study aims to evaluate differences in alignment and clinical outcomes between surgical cervical deformity (CD) patients with a subaxial upper-most instrumented vertebra (UIV) and patients with a UIV at C2. Use of CD-corrective instrumentation in the subaxial cervical spine is considered risky due to narrow subaxial pedicles and vertebral artery anatomy. While C2 fixation provides increased stability, the literature lacks guidelines indicating extension of CD-corrective fusion from the subaxial spine to C2. Methods: Included: operative CD patients with baseline (BL) and 1-year postop (1Y) radiographic data, cervical UIV ≥ C2. Patients were grouped by UIV: C2 or subaxial (C3-C7) and propensity score matched (PSM) for BL cSVA. Mean comparison tests assessed differences in BL and 1Y patient-related, radiographic, and surgical data between UIV groups, and BL-1Y changes in alignment and clinical outcomes. Results: Following PSM, 31 C2 UIV and 31 subaxial UIV patients undergoing CD-corrective surgery were included. Groups did not differ in BL comorbidity burden (P=0.175) or cSVA (P=0.401). C2 patients were older (64 Conclusions: C2 UIV patients showed similar cervical range of motion and baseline to 1-year functional outcomes as patients with a subaxial UIV. C2 UIV patients also showed greater baseline to 1-year horizontal gaze improvement and had complication profiles similar to subaxial UIV patients, demonstrating the radiographic benefit and minimal functional loss associated with extending fusion constructs to C2. In the treatment of adult cervical deformities, extension of the reconstruction construct to the axis may allow for certain clinical benefits with less morbidity than previously acknowledged

    Haemodynamic consequences of changing potassium concentrations in haemodialysis fluids

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    <p>Abstract</p> <p>Background</p> <p>A rapid decrease of serum potassium concentrations during haemodialysis produces a significant increase in blood pressure parameters at the end of the session, even if effects on intra-dialysis pressure are not seen. Paradoxically, in animal models potassium is a vasodilator and decreases myocardial contractility. The purpose of this trial is to study the precise haemodynamic consequences induced by acute changes in potassium concentration during haemodialysis.</p> <p>Methods</p> <p>In 24 patients, 288 dialysis sessions, using a randomised single blind crossover design, we compared six dialysate sequences with different potassium profiles. The dialysis sessions were divided into 3 tertiles, casually modulating potassium concentration in the dialysate between the value normally used K and the two cut-off points K+1 and K-1 mmol/l. Haemodynamics were evaluated in a non-invasive manner using a finger beat-to-beat monitor.</p> <p>Results</p> <p>Comparing K-1 and K+1, differences were found within the tertiles regarding systolic (+5.3, +6.6, +2.3 mmHg, p < 0.05, < 0.05, ns) and mean blood pressure (+4.3, +6.4, -0.5 mmHg, p < 0.01, < 0.01, ns), as well as peripheral resistance (+212, +253, -4 dyne.sec.cm<sup>-5</sup>, p < 0.05, < 0.05, ns). The stroke volume showed a non-statistically-significant inverse trend (-3.1, -5.2, -0.2 ml). 18 hypotension episodes were recorded during the course of the study. 72% with K-1, 11% with K and 17% with K+1 (p < 0.01 for comparison K-1 vs. K and K-1 vs. K+1).</p> <p>Conclusions</p> <p>A rapid decrease in the concentration of serum potassium during the initial stage of the dialysis-obtained by reducing the concentration of potassium in the dialysate-translated into a decrease of systolic and mean blood pressure mediated by a decrease in peripheral resistance. The risk of intra-dialysis hypotension inversely correlates to the potassium concentration in the dialysate.</p> <p>Trial Registration Number</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01224314">NCT01224314</a></p

    Cohort profile: Risk and risk factors for female breast cancer after treatment for childhood and adolescent cancer: an internationally pooled cohort.

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    PURPOSE The International Consortium for Pooled Studies on Subsequent Malignancies after Childhood and Adolescent Cancer was established in 2018 to address gaps in knowledge of risk and risk factors for breast cancer subsequent to childhood/adolescent cancer by pooling individual patient data from seven cohorts. Initially, the pooled cohort will focus on three clinically relevant questions regarding treatment-related subsequent breast cancer risk in female survivors, which are the risk related to low-dose radiotherapy exposure to the chest, specific chemotherapy agents and attained age. PARTICIPANTS The consortium database includes pooled data on 21 892 female survivors from seven cohorts in North America and Europe with a primary cancer diagnosis at <21 years of age, and survival ≥5 years from diagnosis. FINDINGS TO DATE This is a newly established pooled study. The cohort profile summarised the data collected from each included cohort, including childhood cancer diagnosis information and treatment details (ie, radiotherapy fields and cumulative doses, and chemotherapy agents and cumulative doses for each agent). Included cohorts' follow-up started 1951-1981 and ended 2013-2021, respectively, for a median follow-up duration of 24.3 (IQR 18.0-32.8) years since primary cancer diagnosis. The median age at primary cancer diagnosis was 5.4 (IQR 2.5-11.9) years. And the median attained age at last follow-up was 32.2 (IQR 24.0-40.4) years. In all, 4240 (19.4%) survivors were treated with radiotherapy to the chest and 9308 (42.5%) with anthracyclines. At the end of the follow-up, 835 females developed a first subsequent breast cancer, including 635 invasive breast cancer only, 184 carcinomas in situ only (172 ductal carcinomas in situ and 12 lobular carcinomas in situ), and 16 with both an invasive and in situ diagnosis at the same moment. The cumulative incidences of subsequent breast cancer (both invasive and in situ) 25 and 35 years after primary cancer diagnosis were 2.2% and 6.2%, respectively. FUTURE PLANS The consortium is intended to serve as a model and robust source of childhood/adolescent cancer survivor data for elucidating other knowledge gaps on subsequent breast cancer risk, and risk of other subsequent malignancies (including data on males) in the future
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