17 research outputs found

    Influence of quenched dilution on the quasi-long-range ordered phase of the 2d XY model

    Full text link
    The influence of non magnetic impurities in the 2d XY model is investigated through Monte Carlo (MC) simulations. The general picture of the transition is fully understood from the Harris criterion which predicts that the universality class is unchanged, and the Berezinskii-Kosterlitz-Thouless description of the topological transition remains valid. We nevertheless address here the question about the influence of dilution on the quasi-long-range order at low temperatures. In particular, we study the asymptotic of the pair correlation function and report the MC estimates for the critical exponent η\eta at different dilutions. In the weak dilution region, our MC calculations are further supported by simple spin-wave-like calculations.Comment: 8 pages, 7 eps figure

    Kidins220 deficiency causes ventriculomegaly via SNX27-retromer-dependent AQP4 degradation

    Get PDF
    Several psychiatric, neurologic and neurodegenerative disorders present increased brain ventricles volume, being hydrocephalus the disease with the major manifestation of ventriculomegaly caused by the accumulation of high amounts of cerebrospinal fluid (CSF). The molecules and pathomechanisms underlying cerebral ventricular enlargement are widely unknown. Kinase D interacting substrate of 220 kDa (KIDINS220) gene has been recently associated with schizophrenia and with a novel syndrome characterized by spastic paraplegia, intellectual disability, nystagmus and obesity (SINO syndrome), diseases frequently occurring with ventriculomegaly. Here we show that Kidins220, a transmembrane protein effector of various key neuronal signalling pathways, is a critical regulator of CSF homeostasis. We observe that both KIDINS220 and the water channel aquaporin-4 (AQP4) are markedly downregulated at the ventricular ependymal lining of idiopathic normal pressure hydrocephalus (iNPH) patients. We also find that Kidins220 deficient mice develop ventriculomegaly accompanied by water dyshomeostasis and loss of AQP4 in the brain ventricular ependymal layer and astrocytes. Kidins220 is a known cargo of the SNX27-retromer, a complex that redirects endocytosed plasma membrane proteins (cargos) back to the cell surface, thus avoiding their targeting to lysosomes for degradation. Mechanistically, we show that AQP4 is a novel cargo of the SNX27-retromer and that Kidins220 deficiency promotes a striking and unexpected downregulation of the SNX27-retromer that results in AQP4 lysosomal degradation. Accordingly, SNX27 silencing decreases AQP4 levels in wild-type astrocytes whereas SNX27 overexpression restores AQP4 content in Kidins220 deficient astrocytes. Together our data suggest that the KIDINS220-SNX27-retromer-AQP4 pathway is involved in human ventriculomegaly and open novel therapeutic perspectives

    Metalloproteinase MT5-MMP is an essential modulator of neuro-immune interactions in thermal pain stimulation

    Get PDF
    Peripheral interactions between nociceptive fibers and mast cells contribute to inflammatory pain, but little is known about mechanisms mediating neuro-immune communication. Here we show that metalloproteinase MT5-MMP (MMP-24) is an essential mediator of peripheral thermal nociception and inflammatory hyperalgesia. We report that MT5-MMP is expressed by CGRP-containing peptidergic nociceptors in dorsal root ganglia and that Mmp24-deficient mice display enhanced sensitivity to noxious thermal stimuli under basal conditions. Consistently, mutant peptidergic sensory neurons hyperinnervate the skin, a phenotype that correlates with changes in the regulated cleavage of the cell-cell adhesion molecule N-cadherin. In contrast to basal nociception, Mmp24−/− mice do not develop thermal hyperalgesia during inflammation, a phenotype that appears associated with alterations in N-cadherin-mediated cell-cell interactions between mast cells and sensory fibers. Collectively, our findings demonstrate an essential role of MT5-MMP in the development of dermal neuro-immune synapses and suggest that this metalloproteinase may be a target for pain control

    Prosthetic Valve Candida spp. Endocarditis: New Insights into Long-term Prognosis-The ESCAPE Study

    No full text
    Background. Prosthetic valve endocarditis caused by Candida spp. (PVE-C) is rare and devastating, with international guidelines based on expert recommendations supporting the combination of surgery and subsequent azole treatment. Methods. We retrospectively analyzed PVE-C cases collected in Spain and France between 2001 and 2015, with a focus on management and outcome. Results. Forty-six cases were followed up for a median of 9 months. Twenty-two patients (48%) had a history of endocarditis, 30 cases (65%) were nosocomial or healthcare related, and 9 (20%) patients were intravenous drug users. "Induction" therapy consisted mainly of liposomal amphotericin B (L-amB)-based (n = 21) or echinocandin-based therapy (n = 13). Overall, 19 patients (41%) were operated on. Patients <66 years old and without cardiac failure were more likely to undergo cardiac surgery (adjusted odds ratios [aORs], 6.80 [95% confdence interval [CI], 1.59-29.13] and 10.92 [1.15-104.06], respectively). Surgery was not associated with better survival rates at 6 months. Patients who received L-amB alone had a better 6-month survival rate than those who received an echinocandin alone (aOR, 13.52; 95% CI, 1.03-838.10). "Maintenance" fluconazole therapy, prescribed in 21 patients for a median duration of 13 months (range, 2-84 months), led to minor adverse effects. Conclusion. L-amB induction treatment improves survival in patients with PVE-C. Medical treatment followed by long-term maintenance fluconazole may be the best treatment option for frail patients

    Antimicrobial management of Tropheryma whipplei endocarditis: the Spanish Collaboration on Endocarditis (GAMES) experience

    No full text
    OBJECTIVES: Tropheryma whipplei has been detected in 3.5% of the blood culture-negative cases of endocarditis in Spain. Experience in the management of T. whipplei endocarditis is limited. Here we report the long-term outcome of the treatment of previously reported patients who were diagnosed with infective endocarditis (IE) caused by T. whipplei from the Spanish Collaboration on Endocarditis-Grupo de Apoyo al Manejo de la Endocarditis Infecciosa en Espana (GAMES) and discuss potential options for antimicrobial therapy for IE caused by T. whipplei. PATIENTS AND METHODS: Seventeen patients with T. whipplei endocarditis were recruited between 2008 and 2014 in 25 Spanish hospitals. Patients were classified according to the therapeutic regimen: ceftriaxone and trimethoprim/sulfamethoxazole, doxycycline + hydroxychloroquine and other treatment options. RESULTS: Follow-up data were obtained from 14 patients. The median follow-up was 46.5 months. All patients completed the antibiotic treatment prescribed, with a median duration of 13 months. Six patients were treated with ceftriaxone and trimethoprim/sulfamethoxazole (median duration 13 months), four with doxycycline + hydroxychloroquine (median duration 13.8 months) and four with other treatment options (median duration 22.3 months). The follow-up after the end of the treatments was between 5 and 84 months (median 24 months). CONCLUSIONS: All treatment lines were effective and well tolerated. Therapeutic failures were not detected during the treatment. None of the patients died or experienced a relapse during the follow-up. Only six patients received antibiotic treatment in accordance with guidelines. These data suggest that shorter antimicrobial treatments could be effective

    Outpatient Parenteral Antibiotic Treatment for Infective Endocarditis: A Prospective Cohort Study From the GAMES Cohort

    No full text
    BACKGROUND: Outpatient parenteral antibiotic treatment (OPAT) has proven efficacious for treating infective endocarditis (IE). However, the 2001 Infectious Diseases Society of America (IDSA) criteria for OPAT in IE are very restrictive. We aimed to compare the outcomes of OPAT with those of hospital-based antibiotic treatment (HBAT). METHODS: Retrospective analysis of data from a multicenter, prospective cohort study of 2000 consecutive IE patients in 25 Spanish hospitals (2008-2012) was performed. RESULTS: A total of 429 patients (21.5%) received OPAT, and only 21.7% fulfilled IDSA criteria. Males accounted for 70.5%, median age was 68 years (interquartile range [IQR], 56-76), and 57% had native-valve IE. The most frequent causal microorganisms were viridans group streptococci (18.6%), Staphylococcus aureus (15.6%), and coagulase-negative staphylococci (14.5%). Median length of antibiotic treatment was 42 days (IQR, 32-54), and 44% of patients underwent cardiac surgery. One-year mortality was 8% (42% for HBAT; P < .001), 1.4% of patients relapsed, and 10.9% were readmitted during the first 3 months after discharge (no significant differences compared with HBAT). Charlson score (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.04-1.42; P = .01) and cardiac surgery (OR, 0.24; 95% CI, .09-.63; P = .04) were associated with 1-year mortality, whereas aortic valve involvement (OR, 0.47; 95% CI, .22-.98; P = .007) was the only predictor of 1-year readmission. Failing to fulfill IDSA criteria was not a risk factor for mortality or readmission. CONCLUSIONS: OPAT provided excellent results despite the use of broader criteria than those recommended by IDSA. OPAT criteria should therefore be expanded

    Efficacy of β-lactam/β-lactamase inhibitors to treat extended-spectrum beta-lactamase-producing Enterobacterales bacteremia secondary to urinary tract infection in kidney transplant recipients (INCREMENT-SOT Project).

    Get PDF
    BACKGROUND Whether active therapy with β-lactam/β-lactamase inhibitors (BLBLI) is as affective as carbapenems for extended-spectrum β-lactamase-producing Enterobacterales (ESBL-E) bloodstream infection (BSI) secondary to urinary tract infection (UTI) in kidney transplant recipients (KTR) remains unclear. METHODS We retrospectively evaluated 306 KTR admitted to 30 centers from January 2014 to October 2016. Therapeutic failure (lack of cure or clinical improvement and/or death from any cause) at days 7 and 30 from ESBL-E BSI onset were primary and secondary study outcomes, respectively. RESULTS Therapeutic failure at days 7 and 30 occurred in 8.2% (25/306) and 13.4% (41/306) of patients. Hospital-acquired BSI (adjusted OR [aOR]: 4.10; 95% confidence interval [CI]: 1.50-11.20) and Pitt score (aOR: 1.47; 95% CI: 1.21-1.77) were independently associated with therapeutic failure at day 7. Age-adjusted Charlson Index (aOR: 1.25; 95% CI: 1.05-1.48), Pitt score (aOR: 1.72; 95% CI: 1.35-2.17) and lymphocyte count ≤500 cells/μL at presentation (aOR: 3.16; 95% CI: 1.42-7.06) predicted therapeutic failure at day 30. Carbapenem monotherapy (68.6%, primarily meropenem) was the most frequent active therapy, followed by BLBLI monotherapy (10.8%, mostly piperacillin-tazobactam). Propensity score-adjusted models revealed no significant impact of the choice of active therapy (carbapenem-containing versus any other regimen, BLBLI- versus carbapenem-based monotherapy) within the first 72 hours on any of the study outcomes. CONCLUSIONS Our data suggest that active therapy based on BLBLI may be as effective as carbapenem-containing regimens for ESBL-E BSI secondary to UTI in the specific population of KTR. Potential residual confounding and unpowered sample size cannot be excluded (ClinicalTrials.gov identifier: NCT02852902)

    Predictors of mortality in solid-organ transplant recipients with bloodstream infections due to carbapenemase-producing Enterobacterales: the impact of cytomegalovirus disease and lymphopenia

    Get PDF
    Treatment of carbapenemase-producing Enterobacterales bloodstream infections (CPE-BSI) in solid-organ transplant recipients (SOT) is challenging. The objective of this study was to develop a specific score to predict mortality in SOT recipients with CPE-BSI. A multinational, retrospective (2004-2016) cohort study (INCREMENT-SOT, ClinicalTrials.gov NCT02852902) was performed. The main outcome variable was 30-day all-cause mortality. The INCREMENT-SOT-CPE score was developed using logistic regression. The global cohort included 216 patients. The final logistic regression model included the following variables: INCREMENT-CPE mortality score ≥8 (8 points), no source control (3 points), inappropriate empirical therapy (2 points), cytomegalovirus disease (7 points), lymphopenia (4 points), and the interaction between INCREMENT-CPE score ≥8 and CMV disease (minus 7 points). This score showed an area under the receiver operating characteristic curve of 0.82 (95% CI 0.76-0.88) and classified patients into three strata: 0-7 (low mortality), 8-11 (high mortality) and 12-17 (very-high mortality). We performed a stratified analysis of the effect of monotherapy versus combination therapy among 165 patients who received appropriate therapy. Monotherapy was associated with higher mortality only in the very-high (adjusted HR 2.82, 95% CI 1.13-7.06, P=0.03) and high (HR 9.93, 95% CI 2.08-47.40, P=0.004) mortality risk strata. A score-based algorithm is provided for therapy guidance
    corecore