118 research outputs found

    Alloimmunisation to Donor Antigens and Immune Rejection Following Foetal Neural Grafts to the Brain in Patients with Huntington's Disease

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    BACKGROUND: The brain is deemed “immunologically privileged” due to sparse professional antigen-presenting cells and lymphatic drainage, and to the blood-brain barrier. Although the actual extent of this privilege is controversial, there is general consensus about the limited need in intracerebral neural grafts for immunosuppressive regimens comparable to those used in other cases of allotransplantation. This has led over the past fifteen years to the use of either short-term or even no immunosuppression in most clinical trials with foetal neural transplant in patients with Parkinson's and Huntington's disease. METHODOLOGY/PRINCIPAL FINDINGS: We report biological demonstration of alloimmunisation without signs of rejection in four grafted patients out of 13 studied during the course of a clinical trial involving fetal neural transplantation in patients with Huntington's Disease. Biological, radiological and clinical demonstration of an ongoing rejection process was observed in a fifth transplanted patient. The rejection process was, however, fully reversible under immunosuppressive treatment and graft activity recovered within six months. CONCLUSIONS/SIGNIFICANCE: There had been, up to date, no report of documented cases that could have cast a doubt on those procedures. Our results underline the need for a reconsideration of the extent of the so-called immune privilege of the brain and of the follow-up protocols of patients with intracerebral grafts. It also suggests that some of the results obtained in past studies with foetal neural transplants may have been biased by an unrecognized immune response to donor cells

    A genome-wide CRISPR screen identifies a restricted set of HIV host dependency factors

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    Host proteins are essential for HIV entry and replication and can be important nonviral therapeutic targets. Large-scale RNA interference (RNAi)-based screens have identified nearly a thousand candidate host factors, but there is little agreement among studies and few factors have been validated. Here we demonstrate that a genome-wide CRISPR-based screen identifies host factors in a physiologically relevant cell system. We identify five factors, including the HIV co-receptors CD4 and CCR5, that are required for HIV infection yet are dispensable for cellular proliferation and viability. Tyrosylprotein sulfotransferase 2 (TPST2) and solute carrier family 35 member B2 (SLC35B2) function in a common pathway to sulfate CCR5 on extracellular tyrosine residues, facilitating CCR5 recognition by the HIV envelope. Activated leukocyte cell adhesion molecule (ALCAM) mediates cell aggregation, which is required for cell-to-cell HIV transmission. We validated these pathways in primary human CD4 + T cells through Cas9-mediated knockout and antibody blockade. Our findings indicate that HIV infection and replication rely on a limited set of host-dispensable genes and suggest that these pathways can be studied for therapeutic intervention

    Utilization of mechanical power and associations with clinical outcomes in brain injured patients. a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

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    BackgroundThere is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes.MethodsIn this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale <= 12 before intubation) who required mechanical ventilation (MV) >= 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS).ResultsWe included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22).ConclusionsExposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation

    Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

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    Cycle cultural et floraison de l'Ă©chalote, Allium cepa L. var aggregatum (cvs Mikor et Jermor)

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