45 research outputs found

    The role of neutrophils in the upper and lower respiratory tract during influenza virus infection of mice

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    BACKGROUND: Neutrophils have been shown to play a role in host defence against highly virulent and mouse-adapted strains of influenza virus, however it is not clear if an effective neutrophil response is an important factor moderating disease severity during infection with other virus strains. In this study, we have examined the role of neutrophils during infection of mice with influenza virus strain HKx31, a virus strain of the H3N2 subtype and of moderate virulence for mice, to determine the role of neutrophils in the early phase of infection and in clearance of influenza virus from the respiratory tract during the later phase of infection. METHODS: The anti-Gr-1 monoclonal antibody (mAb) RB6-8C5 was used to (i) identify neutrophils in the upper (nasal tissues) and lower (lung) respiratory tract of uninfected and influenza virus-infected mice, and (ii) deplete neutrophils prior to and during influenza virus infection of mice. RESULTS: Neutrophils were rapidly recruited to the upper and lower airways following influenza virus infection. We demonstrated that use of mAb RB6-8C5 to deplete C57BL/6 (B6) mice of neutrophils is complicated by the ability of this mAb to bind directly to virus-specific CD8+ T cells. Thus, we investigated the role of neutrophils in both the early and later phases of infection using CD8+ T cell-deficient B6.TAP-/- mice. Infection of B6.TAP-/- mice with a low dose of influenza virus did not induce clinical disease in control animals, however RB6-8C5 treatment led to profound weight loss, severe clinical disease and enhanced virus replication throughout the respiratory tract. CONCLUSION: Neutrophils play a critical role in limiting influenza virus replication during the early and later phases of infection. Furthermore, a virus strain of moderate virulence can induce severe clinical disease in the absence of an effective neutrophil response

    Biochemical Discrimination between Selenium and Sulfur 1: A Single Residue Provides Selenium Specificity to Human Selenocysteine Lyase

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    Selenium and sulfur are two closely related basic elements utilized in nature for a vast array of biochemical reactions. While toxic at higher concentrations, selenium is an essential trace element incorporated into selenoproteins as selenocysteine (Sec), the selenium analogue of cysteine (Cys). Sec lyases (SCLs) and Cys desulfurases (CDs) catalyze the removal of selenium or sulfur from Sec or Cys and generally act on both substrates. In contrast, human SCL (hSCL) is specific for Sec although the only difference between Sec and Cys is the identity of a single atom. The chemical basis of this selenium-over-sulfur discrimination is not understood. Here we describe the X-ray crystal structure of hSCL and identify Asp146 as the key residue that provides the Sec specificity. A D146K variant resulted in loss of Sec specificity and appearance of CD activity. A dynamic active site segment also provides the structural prerequisites for direct product delivery of selenide produced by Sec cleavage, thus avoiding release of reactive selenide species into the cell. We thus here define a molecular determinant for enzymatic specificity discrimination between a single selenium versus sulfur atom, elements with very similar chemical properties. Our findings thus provide molecular insights into a key level of control in human selenium and selenoprotein turnover and metabolism

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Canonical correlations in elephant grass for energy purposes

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    Elephant grass has the potential to be used as a source for energy production. Besides dry matter yield, other characteristics related to biomass quality are important. The canonic correlation analysis is a multivariate statistical procedure that allows for discovering characteristic associations among groups. The objective of this study was to evaluate the canonic correlation existing between the groups of agronomic traits and biomass traits in elephant-grass genotypes aiming to identify possible associations between the groups of variables in order to use this information in breeding programs of elephant grass for energy. The experiment was conducted at Colégio Estadual Agrícola Antônio Sarlo, located in Campos dos Goytacazes, RJ, Brazil. The evaluation cuts were made in June 2009 and February 2011; the first and third evaluation cuts, respectively. In the first cut, the following morpho-agronomic traits were evaluated: dry matter yield, percentage of dry matter, number of tillers, plant height, stem diameter, percentages of ash, cellulose, lignin, acid detergent fiber and crude protein and calorific value. In the third cut, in addition to the morpho-agronomic traits assessed in the first cut, the leaf-blade width and percentages of ash, cellulose, lignin, acid detergent fiber and neutral detergent fiber were also evaluated. The experimental design was of randomized blocks with 40 genotypes. Variance analysis and canonic correlation were performed between the morpho-agronomic and biomass-quality traits for the cuts isolated. A positive correlation was found between the percentage of dry matter and the fiber content and the plant height and number of tillers and the percentage of crude protein.Keywords: Bioenergy, multivariate, Pennisetum purpureum.African Journal of Biotechnology, Vol 13(31) 3666-367

    Aplicação da Teoria do Cuidado Transpessoal de Jean Watson: uma década de produção brasileira Aplicación de la Teoría del Cuidado Transpersonal de Jean Watson: una década de producción brasileña Jean Watson's Theory of Human Caring: a decade of Brazilian publications

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    Esta revisão sistemática objetivou descrever e analisar a aplicação da Teoria do Cuidado Transpessoal de Jean Watson nas pesquisas divulgadas em publicações de Enfermagem brasileiras dos últimos dez anos. O levantamento bibliográfico abrangeu 34 produções científicas selecionadas nas bases de dados eletrônicas MEDLINE (MEDLARS [Medical Literature Analysis and Retrieval System] On-line), LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde), BDENF (Base de dados de Enfermagem) e SciELO (Scientific Electronic Library On-line), que após aplicação dos critérios de inclusão estabelecidos, compuseram a amostra do estudo. Os resultados apontaram que a Região Sul concentra 61,8% das produções referidas ao tema de estudo, que ela pode ser aplicada nos níveis de atenção primária, secundária e terciária e que 64,7% das produções utilizam os fatores de cuidado propostos por Jean Watson em 1979. Emerge a necessidade de aprimoramento das pesquisas acerca da transformação ocorrida na Teoria do Cuidado Transpessoal, com abordagem do Processo Clinical Caritas, porém como são escassos os estudos referentes a esta temática, dificultam sua utilização prática.<br>Esta revisión sistemática tuvo como objetivo describir y analizar la aplicación de la Teoría del Cuidado Transpersonal de Jean Watson en las investigaciones divulgadas en publicaciones de Enfermería brasileñas de los últimos diez años. El levantamiento bibliográfico abarcó 34 producciones seleccionadas en las bases de datos electrónicas MEDLINE (MEDLARS [Medical Literature Analysis and Retrieval System] On-line), LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud), BDENF (Base de datos de Enfermería) y SciELO (Scientific Electronic Library On-line), que después de la aplicación de los criterios de inclusión establecidos, compusieron la muestra del estudio. Los resultados señalaron que la región Sur concentra el 61,8% de las producciones referidas al tema de estudio, que ella puede ser aplicada en los niveles de atención primaria, secundaria y terciaria y que el 64,7% de las producciones utilizan los factores de cuidado propuestos por Jean Watson en 1979. Surge la necesidad de perfeccionamiento de las investigaciones respecto a la transformación ocurrida en la Teoría del Cuidado Transpersonal, con abordaje del Proceso Clinical Caritas, no obstante como son escasos los estudios referentes a esta temática, dificultan su utilización práctica.<br>This systematic review aimed to describe and analyze the use of Jean Watson's Theory of Human Caring in Brazilian studies in the last ten years. A literature search using MEDLINE (MEDLARS - Medical Literature Analysis and Retrieval System), LILACS (Latin American and Caribbean Health Science Literature) BDENF (Nursing Database), and SciELO (Scientific Electronic Library Online) databases was conducted. A sample of 34 publications met the systematic review inclusion criteria. The results showed that 61.8% of the studies were conducted in the south of Brazil, and these studies suggested that the Theory of Human Caring could be used in the three levels of care: primary, secondary, and tertiary. The majority of publications (64.7%) used the carative factors proposed by Jean Watson in 1979. There is a need for research approaches in respect to changes occurred in the Theory of Human Caring that evolved into the clinical caritas processes. Few studies have tested these new processes. This fact makes difficulty to use them in clinical practice
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