689 research outputs found

    Metabolomics demonstrates divergent responses of two Eucalyptus species to water stress

    Get PDF
    Past studies of water stress in Eucalyptus spp. generally highlighted the role of fewer than five “important” metabolites, whereas recent metabolomic studies on other genera have shown tens of compounds are affected. There are currently no metabolite profiling data for responses of stress-tolerant species to water stress. We used GC–MS metabolite profiling to examine the response of leaf metabolites to a long (2 month) and severe (Ψpredawn < −2 MPa) water stress in two species of the perennial tree genus Eucalyptus (the mesic Eucalyptus pauciflora and the semi-arid Eucalyptus dumosa). Polar metabolites in leaves were analysed by GC–MS and inorganic ions by capillary electrophoresis. Pressure–volume curves and metabolite measurements showed that water stress led to more negative osmotic potential and increased total osmotically active solutes in leaves of both species. Water stress affected around 30–40% of measured metabolites in E. dumosa and 10–15% in E. pauciflora. There were many metabolites that were affected in E. dumosa but not E. pauciflora, and some that had opposite responses in the two species. For example, in E. dumosa there were increases in five acyclic sugar alcohols and four low-abundance carbohydrates that were unaffected by water stress in E. pauciflora. Re-watering increased osmotic potential and decreased total osmotically active solutes in E. pauciflora, whereas in E. dumosa re-watering led to further decreases in osmotic potential and increases in total osmotically active solutes. This experiment has added several extra dimensions to previous targeted analyses of water stress responses in Eucalyptus, and highlights that even species that are closely related (e.g. congeners) may respond differently to water stress and re-waterin

    Neonatal-onset multisystem inflammatory disease responsive to interleukin-1 beta inhibition

    Get PDF
    BACKGROUND:Neonatal-onset multisystem inflammatory disease is characterized by fever, urticarial rash, aseptic meningitis, deforming arthropathy, hearing loss, and mental retardation. Many patients have mutations in the cold-induced autoinflammatory syndrome 1 (CIAS1) gene, encoding cryopyrin, a protein that regulates inflammation.METHODS:We selected 18 patients with neonatal-onset multisystem inflammatory disease (12 with identifiable CIAS1 mutations) to receive anakinra, an interleukin-1-receptor antagonist (1 to 2 mg per kilogram of body weight per day subcutaneously). In 11 patients, anakinra was withdrawn at three months until a flare occurred. The primary end points included changes in scores in a daily diary of symptoms, serum levels of amyloid A and C-reactive protein, and the erythrocyte sedimentation rate from baseline to month 3 and from month 3 until a disease flare.RESULTS:All 18 patients had a rapid response to anakinra, with disappearance of rash. Diary scores improved (P<0.001) and serum amyloid A (from a median of 174 mg to 8 mg per liter), C-reactive protein (from a median of 5.29 mg to 0.34 mg per deciliter), and the erythrocyte sedimentation rate decreased at month 3 (all P<0.001), and remained low at month 6. Magnetic resonance imaging showed improvement in cochlear and leptomeningeal lesions as compared with baseline. Withdrawal of anakinra uniformly resulted in relapse within days; retreatment led to rapid improvement. There were no drug-related serious adverse events.CONCLUSIONS:Daily injections of anakinra markedly improved clinical and laboratory manifestations in patients with neonatal-onset multisystem inflammatory disease, with or without CIAS1 mutations

    A neurogenetic model for the study of schizophrenia spectrum disorders: The International 22q11.2 Deletion Syndrome Brain Behavior Consortium

    Get PDF
    Rare copy number variants contribute significantly to the risk for schizophrenia, with the 22q11.2 locus consistently implicated. Individuals with the 22q11.2 deletion syndrome (22q11DS) have an estimated 25-fold increased risk for schizophrenia spectrum disorders, compared to individuals in the general population. The International 22q11DS Brain Behavior Consortium is examining this highly informative neurogenetic syndrome phenotypically and genomically. Here we detail the procedures of the effort to characterize the neuropsychiatric and neurobehavioral phenotypes associated with 22q11DS, focusing on schizophrenia and subthreshold expression of psychosis. The genomic approach includes a combination of whole genome sequencing and genome-wide microarray technologies, allowing the investigation of all possible DNA variation and gene pathways influencing the schizophrenia-relevant phenotypic expression. A phenotypically rich data set provides a psychiatrically well-characterized sample of unprecedented size (n=1,616) that informs the neurobehavioral developmental course of 22q11DS. This combined set of phenotypic and genomic data will enable hypothesis testing to elucidate the mechanisms underlying the pathogenesis of schizophrenia spectrum disorders

    Human skeletal muscle plasmalemma alters its structure to change its Ca2+-handling following heavy-load resistance exercise

    Get PDF
    High-force eccentric exercise results in sustained increases in cytoplasmic Ca2+ levels ([Ca2+]cyto), which can cause damage to the muscle. Here we report that a heavy-load strength training bout greatly alters the structure of the membrane network inside the fibres, the tubular (t-) system, causing the loss of its predominantly transverse organization and an increase in vacuolation of its longitudinal tubules across adjacent sarcomeres. The transverse tubules and vacuoles displayed distinct Ca2+-handling properties. Both t-system components could take up Ca2+ from the cytoplasm but only transverse tubules supported store-operated Ca2+ entry. The retention of significant amounts of Ca2+ within vacuoles provides an effective mechanism to reduce the total content of Ca2+ within the fibre cytoplasm. We propose this ability can reduce or limit resistance exercise-induced, Ca2+-dependent damage to the fibre by the reduction of [Ca2+]cyto to help maintain fibre viability during the period associated with delayed onset muscle soreness

    Muscle fiber conduction velocity is more affected after eccentric than concentric exercise

    No full text
    It has been shown that mean muscle fiber conduction velocity (CV) can be acutely impaired after eccentric exercise. However, it is not known whether this applies to other exercise modes. Therefore, the purpose of this experiment was to compare the effects of eccentric and concentric exercises on CV, and amplitude and frequency content of surface electromyography (sEMG) signals up to 24 h post-exercise. Multichannel sEMG signals were recorded from biceps brachii muscle of the exercised arm during isometric maximal voluntary contraction (MVC) and electrically evoked contractions induced by motor-point stimulation before, immediately after and 2 h after maximal eccentric (ECC group, N = 12) and concentric (CON group, N = 12) elbow flexor exercises. Isometric MVC decreased in CON by 21.7 ± 12.0% (± SD, p < 0.01) and by 30.0 ± 17.7% (p < 0.001) in ECC immediately post-exercise when compared to baseline. At 2 h post-exercise, ECC showed a reduction in isometric MVC by 24.7 ± 13.7% (p < 0.01) when compared to baseline, while no significant reduction (by 8.0 ± 17.0%, ns) was observed in CON. Similarly, reduction in CV was observed only in ECC both during the isometric MVC (from baseline of 4.16 ± 0.3 to 3.43 ± 0.4 m/s, p < 0.001) and the electrically evoked contractions (from baseline of 4.33 ± 0.4 to 3.82 ± 0.3 m/s, p < 0.001). In conclusion, eccentric exercise can induce a greater and more prolonged reduction in muscle force production capability and CV than concentric exercis

    SIT for African malaria vectors: Epilogue

    Get PDF
    As a result of increased support and the diligent application of new and conventional anti-malaria tools, significant reductions in malaria transmission are being accomplished. Historical and current evolutionary responses of vectors and parasites to malaria interventions demonstrate that it is unwise to assume that a limited suite of tools will remain effective indefinitely, thus efforts to develop new interventions should continue. This collection of manuscripts surveys the prospects and technical challenges for applying a novel tool, the sterile insect technique (SIT), against mosquitoes that transmit malaria. The method has been very successful against many agricultural pest insects in area-wide programs, but demonstrations against malaria vectors have not been sufficient to determine its potential relative to current alternatives, much of which will hinge ultimately upon cost. These manuscripts provide an overview of current efforts to develop SIT and identify key research issues that remain

    Comprehensive assessment of estrogen receptor beta antibodies in cancer cell line models and tissue reveals critical limitations in reagent specificity

    Get PDF
    Estrogen Receptor-β (ERβ) has been implicated in many cancers. In prostate and breast cancer its function is controversial, but genetic studies implicate a role in cancer progression. Much of the confusion around ERβ stems from antibodies that are inadequately validated, yet have become standard tools for deciphering its role. Using an ERβ-inducible cell system we assessed commonly utilized ERβ antibodies and show that one of the most commonly used antibodies, NCL-ER-BETA, is non-specific for ERβ. Other antibodies have limited ERβ specificity or are only specific in one experimental modality. ERβ is commonly studied in MCF-7 (breast) and LNCaP (prostate) cancer cell lines, but we found no ERβ expression in either, using validated antibodies and independent mass spectrometry-based approaches. Our findings question conclusions made about ERβ using the NCL-ER-BETA antibody, or LNCaP and MCF-7 cell lines. We describe robust reagents, which detect ERβ across multiple experimental approaches and in clinical samples.The authors acknowledge the Breast Cancer Research Foundation, Cancer Research UK, ERC Consolidator award (grant number 646876), Cambridge Biomedical Research Campus and Cambridge Cancer Centre, which fund the tissue bank and the Urology Biorepository

    Catheter removal versus retention in the management of catheter-associated enterococcal bloodstream infections

    Get PDF
    It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI. MEthoDs: A 12-month retrospective cohort study of adults with enterococcal CA-BSI was conducted at a tertiary care hospital; clinical, microbiological and outcome data were collected. rEsuLts: A total of 111 patients had an enterococcal CA-BSI. [37.9]; P=0.03), but similar rates of recurrent bacteremia (nine [11.0%] versus two (7.0%); P=0.7) and a similar post-BSI length of hospital stay (median days [range]) (11.1 [1.7 to 63.1 days] versus 9.3 [1.9 to 31.8 days]; P=0.3). Catheter retention was an independent predictor of mortality (OR 3.34 [95% CI 1.21 to 9.26]). ConCLusIons: To the authors&apos; knowledge, the present article describes the largest enterococcal CA-BSI series to date. Mortality was increased among patients who had their catheter retained. Additional prospective studies are necessary to determine the optimal management of enterococcal CA-BSI. [37, Catheter removal versus retention in the management of catheter-associated enterococcal bloodstream infections The aim of the present study was to examine the epidemiology, treatment and subsequent outcomes of patients with enterococcal CA-BSI, comparing patients with retained versus removed catheters. Our hypothesis was that catheter management does not affect patient outcomes. MEthoDs setting Barnes-Jewish Hospital (BJH), a 1250-bed teaching hospital, is the largest hospital in Missouri (USA), and has a referral base that includes the St Louis Metropolitan area, eastern Missouri and western Illinois. It houses all medical specialties, including a stem cell transplantation unit. BJH is affiliated with the Washington University School of Medicine (St Louis, Missiouri, USA). study design A retrospective cohort study of patients with enterococcal CA-BSIs during their hospital stay was performed. CA-BSI was defined as enterococcal bacteremia in a patient with a central venous catheter (CVC) in place for at least 48 h and no alternative source of infection. The hospital&apos;s medical informatics database was queried for blood cultures positive for any Enterococcus species; this dataset was merged with a manually collected dataset of CVC usage in the hospital, which is part of the hospital infection control database. Inclusion and exclusion criteria Adult patients admitted to BJH between January 1, 2006 and December 31, 2006, who presented with, or developed, an enterococcal bloodstream infection and had a CVC present at the time of detection of this infection were included. All types and locations of CVCs were included. Blood cultures were obtained during routine care either peripherally and/or from the CVC. Patients who presented to the hospital with a CVC already in place were included. Patient history and physical examination as well as admitting diagnosis and microbiology results were reviewed to determine whether the catheter was the primary focus of the bacteremia. Patients with a primary focus of bacteremia other than the catheter, patients with a CVC in place for &lt;48 h, and patients who died on the day of the positive blood culture were excluded. Polymicrobial infections were included except concurrent Staphylococcus aureus bacteremia or candidemia within ±3 days of the enterococcal bacteremia (n=20) because both entities are established indications for catheter removal. Data collection Demographic characteristics, medical history, clinical presentation, diagnostic and therapeutic procedures, antibiotic treatment and key markers of outcome (recurrence of bloodstream infection, length of hospital stay after the bloodstream infection, crude mortality) were abstracted from the medical records. Admission Charlson comorbidity and McCabe severity of illness scores were determined. Duration of catheter retention time after the bacteremia was recorded. Information on antibiotic lock therapy was collected; however, this treatment modality was not used in patients from this cohort. Postdischarge mortality at both 30 days and three months after bacteremia was obtained from the Social Security Death Index (www. ssdi-search.com). Definitions Renal insufficiency was defined by a serum creatinine level &gt;132.6 μmol/L. Sepsis and sepsis-induced hypotension were defined using established criteria (13). Appropriate therapy was defined as pathogen-directed treatment with antibiotics matching susceptibilities. A catheter was considered to be retained if it was present for the duration of the hospitalization after the first positive blood culture. Recurrence of bacteremia (used here synonymously with intermittent bacteremia) was defined as a second positive blood culture after ≥1 negative blood culture and an interval of ≥1 day during their hospitalization. Community-onset enterococcal bloodstream infection was defined as having the first positive blood culture drawn within 48 h of hospital admission. Data analysis and statistical methods Data entry was performed using Access and Excel (Microsoft Corporation, USA). Data analysis was performed using SPSS 17 (IBM Corporation, USA). Univariate comparisons among categorical variables and outcome measures were performed using the χ 2 test or Fisher&apos;s exact test. A two-sided P &lt;0.05 was considered to be statistically significant. Also calculated was the absolute difference in proportion (∆ p ) of rates of outcome measures including the 95% CI of this difference to describe the precision of this point estimate. Analysis of the difference in proportions and 95% CI enabled the interpretation of statistical significance (if the 95% CI did not cross zero) as well as clinical significance (if the upper limit of the 95% CI exceeded a predefined difference). An absolute difference in recurrence of bacteremia and mortality rates of 15% was considered to represent a clinically significant difference; this estimate was chosen based on previous literature regarding catheter management and clinical experience (14,15). Comparisons among continuous independent variables were performed using the Student&apos;s t test or Mann-Whitney U test as appropriate. Variables found to have P&lt;0.1 in univariate testing were considered for entry into a forward, stepwise multivariate logistic regression model. The study was approved by the Washington University Human Research Protection Office (#07-0690). rEsuLts Demographics, comorbidities and clinical presentation There were 111 patients with enterococcal CA-BSI who met inclusion criteria. The mean (± SD) age was 58.2±15.3 years; 56 (50.5%) patients were male; and 77 (69.4%) were white. There were 36 (32%) patients admitted to the oncology/bone marrow transplant service. The most frequent comorbidities were malignancies (n=62 [55.9%]), diabetes (n=35 [31.5%]) and renal insufficiency (n=31 [27.9%]). Twenty-five (22.5%) patients had metastatic solid tumours, 28 (25.2%) had leukemia, six (5.4%) had lymphomas and three (2.7%) had nonmetastatic solid tumours. There were 20 (18%) patients who were neutropenic at the time of bloodstream infection. Of all bloodstream infections, 90 (81%) were hospital-acquired. None of the patients were diagnosed with infective endocarditis during the admission. Microbiology Of the enterococcal bloodstream infections, 45 (40.5%) were caused by E faecalis and 61 (55.0%) by E faecium. Of the bacteremias caused by E faecalis, 10 (22.2%) were due to vancomycin-resistant isolates while 57 (93.4%) of the bacteremias caused by E faecium were vancomycin resistant. An additional five (4.5%) infections were caused by other Enterococcus species. A total of 37 patients (33.3%) had polymicrobial infections in which the most common polymicrobial organism was coagulase-negative Staphylococcus (n=26 [23.4%]). There were 24 (34.9%) polymicrobial E faecalis bacteremias and 10 (27.0%) polymicrobial E faecium bacteremias. Additionally, there was no difference in polymicrobial bacteremias among patients who had their catheter removed versus retained (28 [34.1%] versus nine [31.0%]; P=0.8). Vancomycin-susceptible E faecalis caused 30 (36.6%) of 82 infections in which catheters were removed during the hospitalization and five (17.2%) of 29 infections in which they were retained (P=0.09). Vancomycin-resistant E faecium (VRE) caused 42 (51.2%) of infections in which catheters were removed and 15 (51.7%) in which they were retained (P=0.9). Overall, there was no difference in the number of vancomycin-resistant isolates regardless of whether a catheter was removed Catheter management The CVC was retained during the hospitalization in 29 (26.1%) patients. In univariate analysis, patients with removed CVCs were similar to patients whose CVC was retained DIsCussIon Removal of an intravascular catheter is, with few exceptions, considered to be an essential part of managing CA-BSI. However, robust data to support this approach are only available for a limited number of pathogens responsible for these infections. Despite the lack of sufficient data to provide an evidence-based recommendation with regard to CA-BSI caused by Enterococcus species, national guidelines recommend removing the involved catheters (9). To our knowledge, the present study represents the largest investigation into catheter management and outcomes of enterococcal bloodstream infections. The main finding of the present study was increased mortality in patients whose catheters were retained during the hospitalization. Our findings suggest that catheter removal should be considered to improve patient survival. Also, the difference in the two outcome proportions exceeded the predetermined clinically meaningful difference of 15%, which gives us a quantitative estimate of the impact of catheter removal. The patient groups were very similar with respect to demographic characteristics and comorbidities, including adjunctive antibiotic treatment with the aminoglycoside gentamicin. These findings are congruent with the single study encountered in the scientific literature that scrutinized outcomes of enterococcal CA-BSI and specifically investigated catheter management, albeit in a smaller number of patients (11). There, the authors retrospectively examined 61 enterococcal CA-BSI, with 82% of the episodes due to E faecalis and polymicrobial infections found in 18% of the study population. Of note, they did not exclude patients with concurrent Staphylococcus aureus or yeast bloodstream infections, although these infections likely guided catheter management significantly more than the detection of enterococci. Sandoe et al (11) evaluated whether successful treatment of a bloodstream infection was possible without removal of the catheter, which was achieved in five of 13 cases (38%). If the catheter was removed, the chance for cure was higher (40 of 48 [83%]). They found a combination of a cell wall-active agent with an aminoglycoside to be significantly more effective than monotherapy when the catheter was retained. The authors concluded that, although the removal of the catheter was performed in the majority of cases, it did not appear to be a necessary part of the management as long as antimicrobial treatment was optimized. In our study, even though we did not set cure as an end point, 67 (81.7%) of 82 patients with catheters removed survived the hospital admission and 61 (74.4%) survived at 30 days postbacteremia. These rates were much lower for patients with retained catheters. In summary, these data suggest that although enterococcal CA-BSI are not an absolute indication for catheter removal, removal should be favoured over catheter retention. Reasons for catheter retention may have been that the treating physicians of patients who were severely ill at the time of enterococcal bloodstream infection were reluctant to remove the catheter because it was essential for nonantibiotic medications; that the patients had limited options for alternative intravenous access; or that their comorbidities increased the risk of catheter removal and replacement. Catheter management may have been driven by reasons other than the infection alone, and removing the catheter could have been a lower priority or higher risk in the patients&apos; overall medical management. Because we collected crude mortality data, it is also conceivable that patients died from causes not related to the CA-BSI. Of note, we did not observe a difference in recurrence of infection depending on catheter management; it is possible that the size of the cohort prevented us from noting a statistically significant difference. Our patients are notable for a high percentage of comorbid conditions, including metastatic solid tumours (23%) and leukemia (25%); accordingly, the crude in-hospital mortality rate was high in our study population. An independent factor associated with death was the detection of VRE in the stool, which may be a marker for frequent health care exposure. Despite this finding, CA-BSIs with vancomycinresistant E faecium did not result in increased mortality compared with non-VRE infections. This is different from an earlier prospective study and a more recent meta-analysis, in which vancomycin resistance was found to be associated with increased mortality Limitations of the present study include its retrospective design, the fact that the diagnosis of recurrent infection depended on the treating physician ordering blood cultures and that postdischarge outcomes, including completion of planned antibiotic therapy, follow-up blood cultures, and catheter removal postdischarge, were not studied. In addition, catheter management is potentially influenced by other reasons for retention (difficulty of finding alternative access, bleeding diathesis) and we did not report outcomes for different catheter types. Finally, changes in the usage of daptomycin and linezolid have occurred since the time of the study. Although this was the largest study of enterococcal CA-BSI to date, it is still a relatively small sample to detect rare outcomes. ConCLusIons Based on our study findings, catheter removal is preferable to retention in patients with enterococcal CA-BSI. A large prospective or multicentre study should be performed to identify patients at highest risk for mortality and to add strength to our results. DECLArAtIons: None of the following authors has a conflict of interest to declare: J Marschall, ML Piccirillo, J Doherty
    corecore