Stroke attracts neutrophils to the injured brain tissue where they can damage the integrity of the blood–brain barrier and exacerbate the lesion. However, the mechanisms involved in neutrophil transmigration, location and accumulation in the ischemic brain are not fully elucidated. Neutrophils can reach the perivascular spaces of brain vessels after crossing the endothelial cell layer and endothelial basal lamina of post-capillary venules, or migrating from the leptomeninges following pial vessel extravasation and/or a suggested translocation from the skull bone marrow. Based on previous observations of microglia phagocytosing neutrophils recruited to the ischemic brain lesion, we hypothesized that microglial cells might control neutrophil accumulation in the injured brain. We studied a model of permanent occlusion of the middle cerebral artery in mice, including microglia- and neutrophil-reporter mice. Using various in vitro and in vivo strategies to impair microglial function or to eliminate microglia by targeting colony stimulating factor 1 receptor (CSF1R), this study demonstrates that microglial phagocytosis of neutrophils has fundamental consequences for the ischemic tissue. We found that reactive microglia engulf neutrophils at the periphery of the ischemic lesion, whereas local microglial cell loss and dystrophy occurring in the ischemic core are associated with the accumulation of neutrophils first in perivascular spaces and later in the parenchyma. Accordingly, microglia depletion by long-term treatment with a CSF1R inhibitor increased the numbers of neutrophils and enlarged the ischemic lesion. Hence, microglial phagocytic function sets a critical line of defense against the vascular and tissue damaging capacity of neutrophils in brain ischemia. Electronic supplementary material The online version of this article (10.1007/s00401-018-1954-4) contains supplementary material, which is available to authorized users.

BackgroundUp-to-date identification of local trends in sepsis incidence and outcomes is of considerable public health importance. The aim of our study was to estimate annual incidence rates and in-hospital mortality trends for hospitalized patients with sepsis in a European setting, while avoiding selection bias in relation to different complexity hospitals.MethodsA large retrospective analysis of a 5-year period (2008–2012) was conducted of hospital discharge records obtained from the Catalan Health System (CatSalut) Minimum Basic Data Set for Acute-Care Hospitals (a mandatory population-based register of admissions to all public and private acute-care hospitals in Catalonia). Patients hospitalized with sepsis were detected on the basis of ICD-9-CM codes used to identify acute organ dysfunction and infectious processes.ResultsOf 4,761,726 discharges from all acute-care hospitals in Catalonia, 82,300 cases (1.72%) had sepsis diagnoses. Annual incidence was 212.7 per 100,000 inhabitants/year, rising from 167.2 in 2008 to 261.8 in 2012. Length of hospital stay fell from 18.4 to 15.3 days (p < .00001), representing a relative reduction of 17%. Hospital mortality fell from 23.7 to 19.7% (p < .0001), representing a relative reduction of 16.9%. These differences were confirmed in the multivariate analysis (adjusted for age group, sex, comorbidities, ICU admission, emergency admission, organ dysfunction, number of organ failures, sepsis source and bacteraemia).ConclusionsSepsis incidence has risen in recent years, whereas mortality has fallen. Our findings confirm reports for other parts of the world, in the context of scarce administrative data on sepsis in Europe.Electronic supplementary materialThe online version of this article (doi:10.1186/s13613-017-0241-1) contains supplementary material, which is available to authorized users.

Bacteriophages infecting Bacteroides fragilis 40 were found in all kinds of sewage polluted samples. In contrast, they were never recovered either in non-faecally polluted samples or in samples only polluted by wildlife. In simulated laboratory experiments, a selected bacteriophage, B40-8, active against B. fragilis 40 did not replicate either in aerobiosis or under anaerobic conditions, when the culture medium was substituted by either fresh water, seawater or sediments. Inactivation rates of the same bacteriophage were studied in comparison with other viruses such as poliovirus 1, simian rotavirus SA11 and f2 coliphage, showing decay rates similar or inferior to the ones of the other viruses studied. Results herein shown indicate that bacteriophages infecting B.fragilis may be good candidates for a surrogate indicator of human viruses in the environment.

Background: The use of emergency hospital services (EHS) has increased steadily in Spain in the last decade while the number of immigrants has increased dramatically. Studies show that immigrants use EHS differently than native-born individuals, and this work investigates demographics, diagnoses and utilization rates of EHS in Lleida (Spain).

Rising evidence points to endothelial-to-mesenchymal transition (EndMT) as a significant source of the mesenchymal cell population in fibrotic diseases. In this context, we hypothesized that liver endothelial cells undergo EndMT during fibrosis progression. Cirrhosis in mice was induced by CCl A transgenic mouse expressing a red fluorescent protein reporter under the control of Tie2 promoter (Tie2-tdTomato) was used to trace the acquisition of EndMT. Sinusoidal vascular connectivity was evaluated by intravital microscopy and high-resolution three-dimensional confocal microscopy. A modest but significant fraction of liver endothelial cells from both cirrhotic patients and CCl-treated Tie2-tdTomato mice acquired an EndMT phenotype characterized by the coexpression of CD31 and α-smooth muscle actin, compared with noncirrhotic livers. Bone morphogenetic protein-7 (BMP-7) inhibited the acquisition of EndMT induced by transforming growth factor-β1 (TGF-β1) treatment in cultured primary mouse liver endothelial cells from control mice. EndMT was also reduced significantly in vivo in cirrhotic Tie2-tdTomato mice treated intraperitoneally with BMP-7 compared with untreated mice (1.9 ± 0.2 vs. 3.8 ± 0.3%, respectively; < 0.05). The decrease of EndMT in cirrhotic livers correlated with a significant decrease in liver fibrosis ( < 0.05) and an improvement in the vascular disorganization rate ( < 0.05). We demonstrated the acquisition of the EndMT phenotype by a subpopulation of endothelial cells from cirrhotic livers in both animal models and patients. BMP-7 treatment decreases the occurrence of the EndMT phenotype and has a positive impact on the severity of disease by reducing fibrosis and sinusoidal vascular disorganization. A subpopulation of liver endothelial cells from cirrhotic patients and mice with liver fibrosis undergoes endothelial-to-mesenchymal transition. Liver endothelial cells from healthy mice could transition into a mesenchymal phenotype in culture in response to TGF-β1 treatment. Fibrotic livers treated chronically with BMP-7 showed lower EndMT acquisition, reduced fibrosis, and improved vascular organization.