108 research outputs found

    Coupling of the oxygen-linked interaction energy for inositol hexakisphosphate and bezafibrate binding to human HbA0.

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    The energetics of signal propagation between different functional domains (i.e. the binding sites for O2, inositol hexakisphospate (IHP), and bezafibrate (BZF)) of human HbA0 was analyzed at different heme ligation states and through the use of a stable, partially heme ligated intermediate. Present data allow three main conclusions to be drawn, and namely: (i) IHP and BZF enhance each others binding as the oxygenation proceeds, the coupling free energy going from close to zero in the deoxy state to -3.4 kJ/mol in the oxygenated form; (ii) the simultaneous presence of IHP and BZF stabilizes the hemoglobin T quaternary structure at very low O2 pressures, but as oxygenation proceeds it does not impair the transition toward the R structure, which indeed occurs also under these conditions; (iii) under room air pressure (i.e. pO2 = 150 torr), IHP and BZF together induce the formation of an asymmetric dioxygenated hemoglobin tetramer, whose features appear reminiscent of those suggested for transition state species (i.e. T- and R-like tertiary conformation(s) within a quaternary R-like structure)

    Associations of Vaccination and of Prior Infection with Positive PCR Test Results for SARS-CoV-2 in Airline Passengers Arriving in Qatar

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    The SARS-CoV-2 pandemic has severely affected international travel. With efficacious COVID-19 vaccines available, Qatar implemented a pilot program between February 18 and April 26, 2021, to ease travel restrictions by waiving the quarantine requirement for vaccinated residents who received their second vaccine dose at least 14 days before arrival. The program still required a polymerase chain reaction (PCR) test to be performed on each passenger on arrival at Hamad International Airport, Qatar’s international travel gate. We investigated the incidence of PCR-positive test results in arriving passengers

    Assessment of dietary exposure to some persistent organic pollutants in the Republic of Karakalpakstan of Uzbekistan.

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    A 1999 study heightened long-standing concerns over persistent organic pollutant contamination in the Aral Sea area, detecting elevated levels in breast milk and cord blood of women in Karakalpakstan (western Uzbekistan). These findings prompted a collaborative research study aimed at linking such human findings with evidence of food chain contamination in the area. An international team carried out analyses of organochlorine and organophosphate pesticides, polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) on samples of 12 foods commonly produced and consumed in Karakalpakstan. Analysis consistently detected long-lasting organochlorine pesticides and their metabolites in all foods of animal origin and in some vegetables such as onions and carrots--two low-cost components of many traditional dishes. Levels of PCBs were relatively low in all samples except fish. Analyses revealed high levels of PCDDs and PCDFs (together often termed "dioxins") in sheep fat, dairy cream, eggs, and edible cottonseed oil, among other foodstuffs. These findings indicate that food traditionally grown, sold, and consumed in Karakalpakstan is a major route of human exposure to several persistent toxic contaminants, including the most toxic of dioxins, 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). Intake estimations demonstrate that consumption of even small amounts of locally grown food may expose consumers to dioxin levels that considerably exceed the monthly tolerable dioxin intake levels set by the World Health Organization. Data presented in this study allow a first assessment of the risk associated with the consumption of certain food products in Karakalpakstan and highlight a critical public health situation

    Effectiveness of the SARS-CoV-2 mRNA Vaccines in Pregnant Women

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    Pregnancy may increase the risk of adverse maternal and neonatal outcomes in SARS-CoV-2 infection. Effectiveness of SARS-CoV-2 vaccines in pregnant women is not known. Using a test-negative case-control study, we determined the vaccine effectiveness of mRNA vaccines in preventing confirmed SARS-CoV-2 infection in pregnant women at a national referral hospital, which handles > 75% of the deliveries in Qatar. Among 2,020 pregnant women who met the study criteria, 397 had a positive SARS-CoV-2 RT-PCR and 1,623 had a negative test. Vaccine effectiveness ≥ 14 days after the second dose was 67.7% (95%CI 30.5–86.9), while vaccine effectiveness ≥ 14 days after the first dose but before the second dose was 40.3% (95%CI 0.0-80.4). There were nine severe/critical disease cases, and no deaths in the PCR-positive pregnant women, all among unvaccinated. The mRNA vaccines provide high level of protection against documented SARS-CoV-2 infection, which supports including pregnant women in vaccination campaigns

    Priorities for health economic methodological research: Results of an expert consultation

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    Background: The importance of economic evaluation in decision making is growing with increasing budgetary pressures on health systems. Diverse economic evidence is available for a range of interventions across national contexts within Europe, but little attention has been given to identifying evidence gaps that, if filled, could contribute to more efficient allocation of resources. One objective of the Research Agenda for Health Economic Evaluation project is to determine the most important methodological evidence gaps for the ten highest burden conditions in the European Union (EU), and to suggest ways of filling these gaps. Methods: The highest burden conditions in the EU by Disability Adjusted Life Years were determined using the Global Burden of Disease study. Clinical interventions were identified for each condition based on published guidelines, and economic evaluations indexed in MEDLINE were mapped to each intervention. A panel of public health and health economics experts discussed the evidence during a workshop and identified evidence gaps. Results: The literature analysis contributed to identifying cross-cutting methodological and technical issues, which were considered by the expert panel to derive methodological research priorities. Conclusions: The panel suggests a research agenda for health economics which incorporates the use of real-world evidence in the assessment of new and existing interventions; increased understanding of cost-effectiveness according to patient characteristics beyond the “-omics” approach to inform both investment and disinvestment decisions; methods for assessment of complex interventions; improved cross-talk between economic evaluations from health and other sectors; early health technology assessment; and standardized, transferable approaches to economic modeling

    Outcomes Among Patients with Breakthrough SARS-CoV-2 Infection After Vaccination.

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    BACKGROUND: Breakthrough infections after SARS-CoV-2 vaccination have been reported. Clinical outcomes in these persons are not widely known. METHODS: We evaluated all vaccinated persons with breakthrough infection ≥14 days after the second vaccine dose and unvaccinated controls matched on age, sex, nationality, and reason for testing between December 23, 2020 and March 28, 2021 in Qatar. Our primary outcome was severe disease defined as hospitalization, mechanical ventilation, or death. RESULTS: Among 456 persons cases of breakthrough infection and 456 unvaccinated matched controls with confirmed infection, median age was 45 years, 60.7% were males, and ≥1 comorbid condition was present in 61.2% of the vaccinated and 47.8% of the unvaccinated persons (P=0.009). Severe disease was recorded in 48 (10.5%) of the vaccinated and 121 (26.5%) of the unvaccinated group (P40-60 years, HR 2.32; >60-70 years, HR 4.34; >70 years, HR 5.43); presence of symptoms at baseline (HR 2.42, 95%CI 1.44-4.07); and being unvaccinated (HR 2.84, 95%CI 1.80-4.47). CONCLUSIONS: In persons with breakthrough SARS-CoV-2 infection, increasing age is associated with a higher risk of severe disease or death, while vaccination is associated with a lower risk. Presence of comorbidities was not associated with severe disease or death among persons with breakthrough infection

    Effectiveness of the neutralizing antibody sotrovimab among high-risk patients with mild-to-moderate SARS-CoV-2 in Qatar

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    ObjectivesTo estimate the real-world effectiveness of sotrovimab against severe, critical, or fatal COVID-19 in Qatar at a time in which most SARS-CoV-2 incidences occurred due to the BA.2 Omicron subvariant. MethodsWe conducted a matched case-control study among all individuals eligible for sotrovimab treatment per United States Food and Drug Administration guidelines in the resident population of Qatar. The odds of progression to severe forms of COVID-19 were compared in cases (treatment group) versus controls (eligible patients who opted not to receive the treatment). Subgroup analyses were conducted. ResultsA total of 3364 individuals were eligible for sotrovimab treatment during the study period, of whom 519 individuals received the treatment, whereas the remaining 2845 constituted the controls. The adjusted odds ratio of disease progression to severe, critical, or fatal COVID-19 comparing the treatment group to the control group was 2.67 (95% confidence interval 0.60-11.91). In the analysis including only the subgroup of patients at higher risk of severe forms of COVID-19, the adjusted odds ratio was 0.65 (95% confidence interval 0.17-2.48). ConclusionThere was no evidence for a protective effect of sotrovimab in reducing COVID-19 severity in a setting dominated by the BA.2 subvariant
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