27 research outputs found

    Glutathione Is a Key Player in Metal-Induced Oxidative Stress Defenses

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    Since the industrial revolution, the production, and consequently the emission of metals, has increased exponentially, overwhelming the natural cycles of metals in many ecosystems. Metals display a diverse array of physico-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can lead to toxicity and oxidative stress when taken up in excessive amounts, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants possess defense strategies in which glutathione (GSH; Îł-glu-cys-gly) plays a central role as chelating agent, antioxidant and signaling component. Therefore, this review highlights the role of GSH in: (1) metal homeostasis; (2) antioxidative defense; and (3) signal transduction under metal stress. The diverse functions of GSH originate from the sulfhydryl group in cysteine, enabling GSH to chelate metals and participate in redox cycling

    PREDICT identifies precipitating events associated with the clinical course of acutely decompensated cirrhosis

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    Background & Aims: Acute decompensation (AD) of cirrhosis may present without acute-on-chronic liver failure (ACLF) (ADNo ACLF), or with ACLF (AD-ACLF), defined by organ failure(s). Herein, we aimed to analyze and characterize the precipitants leading to both of these AD phenotypes. Methods: The multicenter, prospective, observational PREDICT study (NCT03056612) included 1,273 non-electively hospitalized patients with AD (No ACLF = 1,071; ACLF = 202). Medical history, clinical data and laboratory data were collected at enrolment and during 90-day follow-up, with particular attention given to the following characteristics of precipitants: induction of organ dysfunction or failure, systemic inflammation, chronology, intensity, and relationship to outcome. Results: Among various clinical events, 4 distinct events were precipitants consistently related to AD: proven bacterial infections, severe alcoholic hepatitis, gastrointestinal bleeding with shock and toxic encephalopathy. Among patients with precipitants in the AD-No ACLF cohort and the AD-ACLF cohort (38% and 71%, respectively), almost all (96% and 97%, respectively) showed proven bacterial infection and severe alcoholic hepatitis, either alone or in combination with other events. Survival was similar in patients with proven bacterial infections or severe alcoholic hepatitis in both AD phenotypes. The number of precipitants was associated with significantly increased 90day mortality and was paralleled by increasing levels of surrogates for systemic inflammation. Importantly, adequate first-line antibiotic treatment of proven bacterial infections was associated with a lower ACLF development rate and lower 90-day mortality. Conclusions: This study identified precipitants that are significantly associated with a distinct clinical course and prognosis in patients with AD. Specific preventive and therapeutic strategies targeting these events may improve outcomes in patients with decompensated cirrhosis. Lay summary: Acute decompensation (AD) of cirrhosis is characterized by a rapid deterioration in patient health. Herein, we aimed to analyze the precipitating events that cause AD in patients with cirrhosis. Proven bacterial infections and severe alcoholic hepatitis, either alone or in combination, accounted for almost all (96-97%) cases of AD and acute-on-chronic liver failure. Whilst the type of precipitant was not associated with mortality, the number of precipitant(s) was. This study identified precipitants that are significantly associated with a distinct clinical course and prognosis of patients with AD. Specific preventive and therapeutic strategies targeting these events may improve patient outcomes. (c) 2020 European Association for the Study of the Liver. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

    The PREDICT study uncovers three clinical courses of acutely decompensated cirrhosis that have distinct pathophysiology

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    Acute decompensation (AD) of cirrhosis is defined as the acute development of ascites, gastrointestinal hemorrhage, hepatic encephalopathy, infection or any combination thereof, requiring hospitalization. The presence of organ failure(s) in patients with AD defines acute-on-chronic liver failure (ACLF). The PREDICT study is a European, prospective, observational study, designed to characterize the clinical course of AD and to identify predictors of ACLF. A total of 1,071 patients with AD were enrolled. We collected detailed pre-specified information on the 3-month period prior to enrollment, and clinical and laboratory data at enrollment. Patients were then closely followed up for 3 months. Outcomes (liver transplantation and death) at 1 year were also recorded. Three groups of patients were identified. Pre-ACLF patients (n = 218) developed ACLF and had 3-month and 1-year mortality rates of 53.7% and 67.4%, respectively. Unstable decompensated cirrhosis (UDC) patients (n = 233) required ≥1 readmission but did not develop ACLF and had mortality rates of 21.0% and 35.6%, respectively. Stable decompensated cirrhosis (SDC) patients (n = 620) were not readmitted, did not develop ACLF and had a 1-year mortality rate of only 9.5%. The 3 groups differed significantly regarding the grade and course of systemic inflammation (high-grade at enrollment with aggravation during follow-up in pre-ACLF; low-grade at enrollment with subsequent steady-course in UDC; and low-grade at enrollment with subsequent improvement in SDC) and the prevalence of surrogates of severe portal hypertension throughout the study (high in UDC vs. low in pre-ACLF and SDC). Acute decompensation without ACLF is a heterogeneous condition with 3 different clinical courses and 2 major pathophysiological mechanisms: systemic inflammation and portal hypertension. Predicting the development of ACLF remains a major future challenge. ClinicalTrials.gov number: NCT03056612. Lay summary: Herein, we describe, for the first time, 3 different clinical courses of acute decompensation (AD) of cirrhosis after hospital admission. The first clinical course includes patients who develop acute-on-chronic liver failure (ACLF) and have a high short-term risk of death - termed pre-ACLF. The second clinical course (unstable decompensated cirrhosis) includes patients requiring frequent hospitalizations unrelated to ACLF and is associated with a lower mortality risk than pre-ACLF. Finally, the third clinical course (stable decompensated cirrhosis), includes two-thirds of all patients admitted to hospital with AD - patients in this group rarely require hospital admission and have a much lower 1-year mortality risk

    An ACE2-blocking antibody confers broad neutralization and protection against Omicron and other SARS-CoV-2 variants

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    The ongoing evolution of SARS-CoV-2 has resulted in the emergence of Omicron, which displays striking immune escape potential. Many of its mutations localize to the spike protein ACE2 receptor-binding domain, annulling the neutralizing activity of most therapeutic monoclonal antibodies. Here we describe a receptor-blocking human monoclonal antibody, 87G7, that retains ultrapotent neutralization against SARS-CoV-2 variants including the Alpha, Beta, Gamma, Delta and Omicron (BA.1/BA.2) Variants-of-Concern (VOCs). Structural analysis reveals that 87G7 targets a patch of hydrophobic residues in the ACE2-binding site that are highly conserved in SARS-CoV-2 variants, explaining its broad neutralization capacity. 87G7 protects mice and/or hamsters against challenge with all current SARS-CoV-2 VOCs. Our findings may aid the development of sustainable antibody-based strategies against COVID-19 that are more resilient to SARS-CoV-2 antigenic diversity.The MANCO project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 101003651). This work made use of the Dutch national e infrastructure with the support of the SURF Cooperative using grant no. EINF-2453. This research was funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) - 398066876/GRK 2485/1; BMBF (Federal Ministry of Education and Research) project entitled RAPID (Risk assessment in re-pandemic respiratory infectious diseases), 01KI1723G, Ministry of Science and Culture of Lower Saxony in Germany (14 - 76103-184 CORONA-15/20)N

    An ACE2-blocking antibody confers broad neutralization and protection against Omicron and other SARS-CoV-2 variants of concern

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    The ongoing evolution of SARS-CoV-2 has resulted in the emergence of Omicron, which displays striking immune escape potential through mutations at key antigenic sites on the spike protein. Many of these mutations localize to the spike protein ACE2 receptor-binding domain, annulling the neutralizing activity of therapeutic antibodies that were effective against other Variants of Concern (VOCs) earlier in the pandemic. Here, we identified a receptor-blocking human monoclonal antibody, 87G7, that retained potent in vitro neutralizing activity against SARS-CoV-2 variants including the Alpha, Beta, Gamma, Delta and Omicron (BA.1/BA.2) VOCs. Using cryo-electron microscopy and site-directed mutagenesis experiments, we showed that 87G7 targets a patch of hydrophobic residues in the ACE2-binding site that are highly conserved in SARS-CoV-2 variants, explaining its broad neutralization capacity. 87G7 protected mice and/or hamsters prophylactically against challenge with all current SARS-CoV-2 VOCs, and showed therapeutic activity against SARS-CoV-2 challenge in both animal models. Our findings demonstrate that 87G7 holds promise as a prophylactic or therapeutic agent for COVID-19 that is more resilient to SARS-CoV-2 antigenic diversity.The MANCO project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 101003651). This work made use of the Dutch national e-infrastructure with the support of the SURF Cooperative using grant no. EINF-2453. This research was funded by the Deutsche Forschungsgemeinschaft (DFG; German Research Foundation) -398066876/GRK 2485/1; BMBF (Federal Ministry of Education and Research) project entitled RAPID (Risk assessment in re-pandemic respiratory infectious diseases), 01KI1723G, Ministry of Science and Culture of Lower Saxony in Germany (14 - 76103-184 CORONA-15/20)Peer reviewe

    Beyond the merchant and the clergyman: assessing moral claims about development cooperation

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    This article proposes to move beyond the categories of altruism and self-interest in the analyses of the motives for development cooperation. This opposition ignores the inherently moral nature of development policy. The article illustrates the shortcomings of such a perspective by tracing the metaphor of the merchant and the clergyman as archetypical figures shaping Dutch development policy. Through these images the suggestion of an opposition between moral and amoral motives in the history of development has gained a strong foothold within the interplay of scholars, policy makers and public opinion. We go on to assess claims about economy, security, solidarity, prestige and guilt, and ecology, which have been brought forward to legitimise Dutch foreign aid. This analysis calls for research on the dynamics of the transnational exchanges of ideas, interests and expectations, especially during episodes when the moral validity of policy has been explicitly contested
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