574 research outputs found

    A 10-year study of background surface ozone concentrations on the island of Gozo in the Central Mediterranean

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    A 10-year study of surface ozone mixing ratios in the Central Mediterranean was conducted based on continuous ozone measurements from 1997 to 2006 by a background regional Global Atmospheric Watch (GAW) station on the island of Gozo. The mean annual maximum mixing ratio is of the order of 66 ppbv in April–May with a broad secondary maximum of 64 ppbv in July–September. No long-term increase or decrease in the background level of surface ozone could be observed over the last 10 years. This is contrary to observations made in the Eastern Mediterranean, where a slow decrease in the background ozone mixing ratio was observed over the past 7 years. Despite the very high average annual ozone mixing ratio exceeding 50 ppbv—in fact, the highest average background ozone mixing ratio ever measured in Europe—, the diurnal O3 max/O3 min index of <1.40 indicates that the island of Gozo is a good site for measuring background surface ozone. However, frequent photosmog events from June to September during the past 10 years with ozone mixing ratios exceeding 90 ppbv indicate that the Central Mediterranean is prone to long-range transport of air pollutants from Europe by northerly winds. This was particularly evident during the so-called “August heatwave” of the year 2003 when the overall ozone mixing ratio was 4.6 ppbv higher than the average of all other 9 months of August since 1997. Air mass back-trajectory analysis of the August 2003 photosmog episodes on Gozo confirmed that ozone pollution originated from the European continent. Regression analysis was used to analyse the 10-year data set in order to model the behaviour of the ozone mixing ratio in terms of the meteorological parameters of wind speed, relative humidity, global radiation, temperature, month of year, wind sector, atmospheric pressure, and time of day (predictors). Most of these predictors were found to significantly affect the ozone mixing ratios. From March to November, the monthly average of the AOT40 threshold value for the protection of crops and vegetation against ozone was constantly exceeded on Gozo during the past 10 years.peer-reviewe

    Osteoartropatia hipertrĂłfica pneumica em cĂŁes

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    Seven dogs (5 females and  2 males), with ages varying between 5 and  10 years’s old, showing pneumic osteo-arthropathy were studied. This condition was caused as follows: one by esophagic parasitic nodule (Spirocerca lupi) and aortic aneurysm; one by bronchogenic carcinoma with lung metastasis; another by lung metastasis from ovary digerminoma; two by lung metastasis from mammary adenocarcinoma and two esophagic sarcomas, the former being polymorphic and the latter osteogenic, both originated from parasitic granlomn (Spirocerca lupi). X-rays were taken and after that the animals were submitted to post mortem examination. Six related radiographic figures are shown in the paper.Foram estudados sete animais. 5 fêmeas e 2 machos, com idades que variavam entre 5 e 10 anos, portadores de osteoartropatia pneumica secundária, a nódulo parasitário (Spirocerca lupi) esofágico e aneurisma aórtico, a carcinoma broncogênico com metástases pulmonares, a metástases pulmonares de digerminoma de ovário; a metástases pulmonares de adenocarcinoma mamário (2 casos), a 2 sarcomas de esôfago sendo um polimorfo celular e o outro osteogênico, ambos correlacionados a granulomas de Spirocerca lupi. Os casos foram documentados radiograficamente e os animais posteriormente necropsiados

    Microglia-mediated demyelination protects against CD8+ T cell-driven axon degeneration in mice carrying PLP defects

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    Axon degeneration and functional decline in myelin diseases are often attributed to loss of myelin but their relation is not fully understood. Perturbed myelinating glia can instigate chronic neuroinflammation and contribute to demyelination and axonal damage. Here we study mice with distinct defects in the proteolipid protein 1 gene that develop axonal damage which is driven by cytotoxic T cells targeting myelinating oligodendrocytes. We show that persistent ensheathment with perturbed myelin poses a risk for axon degeneration, neuron loss, and behavioral decline. We demonstrate that CD8(+) T cell-driven axonal damage is less likely to progress towards degeneration when axons are efficiently demyelinated by activated microglia. Mechanistically, we show that cytotoxic T cell effector molecules induce cytoskeletal alterations within myelinating glia and aberrant actomyosin constriction of axons at paranodal domains. Our study identifies detrimental axon-glia-immune interactions which promote neurodegeneration and possible therapeutic targets for disorders associated with myelin defects and neuroinflammation. Demyelination is often suggested to cause axonal degeneration. Here, the authors study mice carrying distinct PLP defects and reveal how persistent ensheathment with perturbed myelin poses a risk for CD8+T cell-driven axon loss and behavioral decline

    Comparison of survival in patients with T cell lymphoma after autologous and allogeneic stem cell transplantation as a frontline strategy or in relapsed disease.

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    We studied the roles of autologous (A) and allogeneic (allo) stem cell transplantation (SCT) in the treatment of 134 patients with T cell lymphoma (TCL) at our center. For frontline SCT, 58 patients were studied. The 4-year overall survival (OS) rates for ASCT (n = 47; median age, 49 years) and alloSCT (n = 11; median age, 55 years) groups were 76% and 54%, respectively (P \u3e .05). The 4-year OS rates for first complete remission (CR1) patients were 84% and 83%, respectively. For SCT for relapsed disease, 76 patients were studied (41 with ASCT and 35 with alloSCT). The 4-year OS rates were 50% and 36% for ASCT and alloSCT patients with chemosensitive disease, respectively (P \u3e .05). Those who were in CR2 and CR3 had 4-year OS rates of 59% and 53%, respectively. Similar results were also observed in patients with refractory disease (29% and 35%, respectively). These data suggest that a pre-SCT CR is associated with improved outcomes in TCL patients after SCT. Considering the 84% 4-year OS rates in CR1 patients and the unpredictable responses in patients with relapsed disease, we favor the use of ASCT as consolidation therapy after CR1. AlloSCT did not result in a superior outcome compared with ASCT

    Extracorporeal liver assist device to exchange albumin and remove endotoxin in acute liver failure: Results of a pivotal pre-clinical study

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    Background & AimsIn acute liver failure, severity of liver injury and clinical progression of disease are in part consequent upon activation of the innate immune system. Endotoxaemia contributes to innate immune system activation and the detoxifying function of albumin, critical to recovery from liver injury, is irreversibly destroyed in acute liver failure. University College London-Liver Dialysis Device is a novel artificial extracorporeal liver assist device, which is used with albumin infusion, to achieve removal and replacement of dysfunctional albumin and reduction in endotoxaemia. We aimed to test the effect of this device on survival in a pig model of acetaminophen-induced acute liver failure.MethodsPigs were randomised to three groups: Acetaminophen plus University College London-Liver Dialysis Device (n=9); Acetaminophen plus Control Device (n=7); and Control plus Control Device (n=4). Device treatment was initiated two h after onset of irreversible acute liver failure.ResultsThe Liver Dialysis Device resulted in 67% reduced risk of death in acetaminophen-induced acute liver failure compared to Control Device (hazard ratio=0.33, p=0.0439). This was associated with 27% decrease in circulating irreversibly oxidised human non-mercaptalbumin-2 throughout treatment (p=0.046); 54% reduction in overall severity of endotoxaemia (p=0.024); delay in development of vasoplegia and acute lung injury; and delay in systemic activation of the TLR4 signalling pathway. Liver Dialysis Device-associated adverse clinical effects were not seen.ConclusionsThe survival benefit and lack of adverse effects would support clinical trials of University College London-Liver Dialysis Device in acute liver failure patients

    Predictors and moderators of outcome of psychotherapeutic interventions for mental disorders in adolescents and young adults : protocol for systematic reviews

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    Background: Adolescence and young adulthood is a risk period for the emergence of mental disorders. There is strong evidence that psychotherapeutic interventions are effective for most mental disorders. However, very little is known about which of the different psychotherapeutic treatment modalities are effective for whom. This large systematic review aims to address this critical gap within the literature on non-specific predictors and moderators of the outcomes of psychotherapeutic interventions among adolescents and young adults with mental disorders. Methods: The protocol is being reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) Statement. PubMed and PsycINFO databases will be searched for randomized controlled and quasi-experimental/naturalistic clinical trials. Risk of bias of all included studies will be assessed by the Mixed Methods Appraisal Tool. The quality of predictor and moderator variables will be also assessed. A narrative synthesis will be conducted for all included studies. Discussion: This systematic review will strengthen the evidence base on effective mental health interventions for young people, being the first to explore predictors and moderators of outcome of psychotherapeutic interventions for a wide range of mental disorders in young people.Peer reviewe

    Saquinavir Inhibits the malaria parasite's chloroquine resistance transporter

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    The antiretroviral protease inhibitors (APIs) ritonavir, saquinavir, and lopinavir, used to treat HIV infection, inhibit the growth of Plasmodium falciparum at clinically relevant concentrations. Moreover, it has been reported that these APIs potentiate the activity of chloroquine (CQ) against this parasite in vitro. The mechanism underlying this effect is not understood, but the degree of chemosensitization varies between the different APIs and, with the exception of ritonavir, appears to be dependent on the parasite exhibiting a CQ-resistant phenotype. Here we report a study of the role of the P. falciparum chloroquine resistance transporter (PfCRT) in the interaction between CQ and APIs, using transgenic parasites expressing different PfCRT alleles and using the Xenopus laevis oocyte system for the heterologous expression of PfCRT. Our data demonstrate that saquinavir behaves as a CQ resistance reverser and that this explains, at least in part, its ability to enhance the effects of CQ in CQ-resistant P. falciparum parasites. Copyrigh
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