95 research outputs found

    Non-O157 Shiga Toxin–Producing \u3ci\u3eEscherichia coli\u3c/i\u3e Infections in the United States, 1983–2002

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    Background. Shiga toxin–producing Escherichia coli (STEC) O157:H7 is a well-recognized cause of bloody diarrhea and hemolytic-uremic syndrome (HUS). Non-O157 STEC contribute to this burden of illness but have been underrecognized as a result of diagnostic limitations and inadequate surveillance. Methods. Between 1983 and 2002, 43 state public health laboratories submitted 940 human non-O157 STEC isolates from persons with sporadic illnesses to the Centers for Diseases Control and Prevention reference laboratory for confirmation and serotyping. Results. The most common serogroups were O26 (22%), O111 (16%), O103 (12%), O121 (8%), O45 (7%), and O145 (5%). Non-O157 STEC infections were most frequent during the summer and among young persons (median age, 12 years; interquartile range, 3–37 years). Virulence gene profiles were as follows: 61% stx1 but not stx2; 22% stx2 but not stx1; 17% both stx1 and stx2; 84% intimin (eae); and 86% enterohemolysin (E-hly). stx2 was strongly associated with an increased risk of HUS, and eae was strongly associated with an increased risk of bloody diarrhea. STEC O111 accounted for most cases of HUS and was also the cause of 3 of 7 non-O157 STEC outbreaks reported in the United States. Conclusions. Non-O157 STEC can cause severe illness that is comparable to the illness caused by STEC O157. Strains that produce Shiga toxin 2 are much more likely to cause HUS than are those that produce Shiga toxin 1 alone. Improving surveillance will more fully elucidate the incidence and pathological spectrum of these emerging agents. These efforts require increased clinical suspicion, improved clinical laboratory isolation, and continued serotyping of isolates in public health laboratories

    Enterotoxin-producing Escherichia coli O169:H41, United States

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    From 1996 to 2003, 16 outbreaks of enterotoxigenic Escherichia coli (ETEC) infections in the United States and on cruise ships were confirmed. E. coli serotype O169:H41 was identified in 10 outbreaks and was the only serotype in 6. This serotype was identified in 1 of 21 confirmed ETEC outbreaks before 1996

    Intravenous dosing of tocilizumab in patients younger than two years of age with systemic juvenile idiopathic arthritis

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    The anti-interleukin-6 receptor-alpha antibody tocilizumab was approved for intravenous (IV) injection in the treatment of patients with systemic juvenile idiopathic arthritis (sJIA) aged 2 to 17 years based on results of a randomized controlled phase 3 trial. Tocilizumab treatment in systemic juvenile idiopathic arthritis (sJIA) patients younger than 2 was investigated in this open-label phase 1 trial and compared with data from the previous trial in patients aged 2 to 17 years.Patients younger than 2 received open-label tocilizumab 12 mg/kg IV every 2 weeks (Q2W) during a 12-week main evaluation period and an optional extension period. The primary end point was comparability of pharmacokinetics during the main evaluation period to that of the previous trial (in patients aged 2-17 years), and the secondary end point was safety; pharmacodynamics and efficacy end points were exploratory. Descriptive comparisons for pharmacokinetics, pharmacodynamics, safety, and efficacy were made with sJIA patients aged 2 to 17 years weighing < 30 kg (n = 38) who received tocilizumab 12 mg/kg IV Q2W in the previous trial (control group).Eleven patients (mean age, 1.3 years) received tocilizumab during the main evaluation period. The primary end point was met: tocilizumab exposures for patients younger than 2 were within the range of the control group (mean [±SD] Όg/mL concentration at the end-of-dosing interval [Cmin]: 39.8 [±14.3] vs 57.5 [±23.3]; maximum concentration [Cmax] postdose: 288 [±40.4] vs 245 [±57.2]). At week 12, pharmacodynamic measures were similar between patients younger than 2 and the control group; mean change from baseline in Juvenile Arthritis Disease Activity Score-71 was - 17.4 in patients younger than 2 and - 28.8 in the control group; rash was reported by 14.3 and 13.5% of patients, respectively. Safety was comparable except for the incidence of serious hypersensitivity reactions (27.3% in patients younger than 2 vs 2.6% in the control group).Tocilizumab 12 mg/kg IV Q2W provided pharmacokinetics, pharmacodynamics, and efficacy in sJIA patients younger than 2 comparable to those in patients aged 2 to 17 years. Safety was comparable except for a higher incidence of serious hypersensitivity events in patients younger than 2 years.Juvenile idiopathic arthritis.ClinicalTrials.gov, NCT01455701 . Registered, October 20, 2011, Date of enrollment of first participant: October 26, 2012

    Influence of Substrates on the Surface Characteristics and Membrane Proteome of Fibrobacter succinogenes S85

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    Although Fibrobacter succinogenes S85 is one of the most proficient cellulose degrading bacteria among all mesophilic organisms in the rumen of herbivores, the molecular mechanism behind cellulose degradation by this bacterium is not fully elucidated. Previous studies have indicated that cell surface proteins might play a role in adhesion to and subsequent degradation of cellulose in this bacterium. It has also been suggested that cellulose degradation machinery on the surface may be selectively expressed in response to the presence of cellulose. Based on the genome sequence, several models of cellulose degradation have been suggested. The aim of this study is to evaluate the role of the cell envelope proteins in adhesion to cellulose and to gain a better understanding of the subsequent cellulose degradation mechanism in this bacterium. Comparative analysis of the surface (exposed outer membrane) chemistry of the cells grown in glucose, acid-swollen cellulose and microcrystalline cellulose using physico-chemical characterisation techniques such as electrophoretic mobility analysis, microbial adhesion to hydrocarbons assay and Fourier transform infra-red spectroscopy, suggest that adhesion to cellulose is a consequence of an increase in protein display and a concomitant reduction in the cell surface polysaccharides in the presence of cellulose. In order to gain further understanding of the molecular mechanism of cellulose degradation in this bacterium, the cell envelope-associated proteins were enriched using affinity purification and identified by tandem mass spectrometry. In total, 185 cell envelope-associated proteins were confidently identified. Of these, 25 proteins are predicted to be involved in cellulose adhesion and degradation, and 43 proteins are involved in solute transport and energy generation. Our results supports the model that cellulose degradation in F. succinogenes occurs at the outer membrane with active transport of cellodextrins across for further metabolism of cellodextrins to glucose in the periplasmic space and inner cytoplasmic membrane

    A quantitative synthesis of the medicinal ethnobotany of the Malinké of Mali and the Ashåninka of Peru, with a new theoretical framework

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    <p>Abstract</p> <p>Background</p> <p>Although ethnomedically and taxonomically guided searches for new medicinal plants can improve the percentage of plants found containing active compounds when compared to random sampling, ethnobotany has fulfilled little of its promise in the last few decades to deliver a bounty of new, laboratory-proven medicinal plants and compounds. It is quite difficult to test, isolate, and elucidate the structure and mechanism of compounds from the plethora of new medicinal plant uses described each year with limited laboratory time and resources and the high cost of clinical trials of new drug candidates.</p> <p>Methods</p> <p>A new quantitative theoretical framework of mathematical formulas called "relational efficacy" is proposed that should narrow down this search for new plant-derived medicines based on the hypothesis that closely related plants used to treat closely related diseases in distantly related cultures have a higher probability of being effective because they are more likely to be independent discoveries of similar plant compounds and disease mechanisms. A prerequisite to this hypothesis, the idea that empirical testing in traditional medicine will lead to choosing similar medicinal plants and therefore the medicinal flora of two distant cultures will prove to be more similar than their general flora, is tested using resampling statistics on cross-cultural field data of the plants used by the MalinkĂ© of Mali and the AshĂĄninka of Peru to treat the diseases malaria, African sleeping sickness, Chagas' disease, leishmaniasis, diabetes, eczema, asthma, and uterine fibroids.</p> <p>Results</p> <p>In this case, the similarity of the medicinal floras is found to be significantly greater than the similarity of the general floras, but only when the diseases in question are grouped into the categories of parasitic and autoimmune diseases.</p> <p>Conclusion</p> <p>If the central theoretical framework of this hypothesis is shown to be true, it will allow the synthesis of medicinal plant information from around the world to pinpoint the species with the highest potential efficacy to take into the laboratory and analyze further, ultimately saving much field and laboratory time and resources.</p> <p><b>Spanish abstract</b></p> <p>Las bĂșsquedas que utilizan la etnomedicina y la taxonomĂ­a para descubrir nuevas plantas medicinales, pueden aumentar la probabilidad de Ă©xito de encontrar compuestos quĂ­micos activos en plantas, en comparaciĂłn con las bĂșsquedas aleatorias. A pesar de lo anterior, en las Ășltimas dĂ©cadas, la etnobotĂĄnica no ha cumplido con las expectativas de proveer numerosas plantas medicinales y quĂ­micos nuevos una vez examinados en el laboratorio. Cada año se describen una plĂ©tora de plantas medicinales y sus usos, sin embargo las limitaciones de tiempo y recursos en los laboratorios, unidos al alto coste de los ensayos clĂ­nicos de las drogas potenciales, hacen muy difĂ­cil probar, aislar, y elucidar la estructura y el mecanismo de los compuestos de estas plantas. Se propone un nuevo marco teĂłrico cuantitativo cuyo fin es focalizar la bĂșsqueda de nueva plantas medicinales. Este marco teĂłrico estĂĄ basado en la hipĂłtesis que las plantas cercanamente relacionadas, usadas para tratar enfermedades cercanamente relacionadas en culturas distantemente relacionadas, tienen una eficacia potencial mĂĄs alta, debido a que es mĂĄs probable que estos hallazgos sean descubrimientos independientes de compuestos quĂ­micos similares. Parte de esta hipĂłtesis, que las escogencias racionales se hacen para elegir plantas medicinales similares y que la flora medicinal de dos culturas distantes es mĂĄs similar que su flora general, se probĂł usando mĂ©todos estadĂ­sticos de remuestreo con datos de campo de la comunidad MalinkĂ© de MalĂ­ y de la AshĂĄninka de PerĂș, y las enfermedades de paludismo, enfermedad africana del sueño, enfermedad de Chagas, leishmania, diabetes, eczema, asma, y fibromas uterinos. Se encontrĂł, en este caso, que la similitud de las floras medicinales es significativamente mayor a la similitud de las floras generales, solamente cuando las enfermedades analizadas se agruparon en las categorĂ­as de enfermedades parasitarias y enfermedades autoinmunes. Si se demostrara que las otras partes de esta hipĂłtesis son ciertas, se podrĂ­a sintetizar la informaciĂłn sobre plantas medicinales alrededor del mundo, para establecer asĂ­ las plantas potencialmente mĂĄs eficaces para llevarlas al laboratorio y analizarlas mĂĄs profundamente.</p> <p><b>French abstract</b></p> <p>Par rapport aux recherches menĂ©es de façon alĂ©atoire, les recherches effectuĂ©es par des critĂšres ethnobotaniques et taxonomiques ont de meilleures chances Ă  dĂ©couvrir de nouvelles plantes mĂ©dicinales Ă  produit chimique actifs. Pendant les derniĂšres dĂ©cennies pourtant, l'ethnobotanique a rĂ©alisĂ© peu de ces promesses Ă  rĂ©vĂ©ler un grand nombre de plantes mĂ©dicinales et de nouveaux produits chimiques, testĂ©s au laboratoire. Avec les ressources limitĂ©es pour la recherche au laboratoire et le coĂ»t Ă©levĂ© des Ă©preuves cliniques pour trouver de nouveaux candidats aux mĂ©dicaments, il est difficile d'Ă©tudier, d'isoler et d'Ă©lucider la structure et le mĂ©canisme des produits chimiques de chacune des nombreuses plantes mĂ©dicinales (et les utilisations de ces plantes) dĂ©crites chaque annĂ©e. Nous proposons une nouvelle technique thĂ©orique et quantitative pour prĂ©ciser la recherche de nouvelles plantes mĂ©dicinales; elle est basĂ©e sur l'hypothĂšse que les plantes Ă©troitement apparentĂ©es, employĂ©es pour traiter les maladies Ă©troitement apparentĂ©es dans les cultures trĂšs Ă©loignĂ©es les unes des autres, ont une potentialitĂ© d'efficacitĂ© supĂ©rieure parce qu'elles reprĂ©sentent la dĂ©couverte indĂ©pendante des propriĂ©tĂ©s chimiques semblables des plantes. Une partie de cette hypothĂšse-qui dĂ©montre que la sĂ©lection des plantes mĂ©dicinales semblables est un choix rationnel et qu'il y a davantage de ressemblance dans la flore mĂ©dicinale de deux cultures Ă©loignĂ©es que dans leur flore gĂ©nĂ©rale-est examinĂ©e par un re-Ă©chantillonnage des donnĂ©es de recherches effectuĂ©es parmi les MalinkĂ© au Mali et les AshĂĄninka au PĂ©rou, en particulier sur la malaria, la maladie africaine du sommeil, la maladie de Chagas, la leishmania, le diabĂšte, l'eczĂ©ma, l'asthme et les fibromes utĂ©rins. Dans ces cas prĂ©cis, la similitude de la flore mĂ©dicinale s'avĂšre sensiblement plus grande que la similitude de la flore gĂ©nĂ©rale, mais seulement quand les maladies en question sont regroupĂ©es ensemble comme maladies parasitaires et auto-immunitaires. Si cette hypothĂšse est prouvĂ©e, elle permettra la synthĂšse des informations recueillies sur les plantes mĂ©dicinales du monde entier pour en sĂ©lectionner de façon plus prĂ©cise celles qui sont les plus efficaces et qui mĂ©ritent analyse plus approfondie au laboratoire.</p> <p><b>AshĂĄninka abstract</b></p> <p>Aayiantyarori irĂČpero aavintane, ontzimatye ancovacovatero ayotero ovaqueraripaye incashi iyoyetziri ashaninka, ayotzityaro aajatzi iyotane viracocha paitachari "quimica" ancantero aaca oshintsinka inchashipaye. Atziri yotacotzirori cametsa, ishtoriajacotzirori iyotane ashaninkapaye te iroñàrantero maaroni ocaratzi yamenacotaqueri laboratorioki. Aaviantyarori cametsa, ayotacotero aavintarontsiyetatsiri osamani antzimaventero ishtoriatacotaro, aajatzi osheki opinata ampinaventero aparopaye inchashi, acoviriqui ayotacotero, osaretsikipaye. Tzimatsi ovaquerari quenquishiriantsitatsiri ero opinata osheki ashitoriatacotero aparopaye inchashi, asampiyetatyrey pashinipaye atziri saicatsiri intaina puitarika inchasshi yavintari, ajatzirica oshiyaro ayotzi aaca, quemetachari atziri saikatsiri nampitsiki malinke aajatzi ishiyari ashaninka saicatsiri peruki, tzimatsi inchashi aajatzi yaavintari osheki okamĂštsatzi aririka anteri mantsiyarentsi icantaitziri ompetarentsi catsirentsi, pochokirentsi, patsarontsi(matatsi) ashipetate maaroni, ampochavathate, ancainikentsite, oncatsithakite tsinani. Aririka añaker aajatzi ahiyaro inchashi yaavintayetari pashinipaye atziri intainasatzi irdotake ahitoriatacoperoteri anĂ ashityard aavintarontsi ovamairiri shithanentsi, onĂ shitaavintarontsi tzicaacoventairi ero antane mantsiyarentsi. Omanperotatyarica irĂČperotzi avintarontsi, oshitovake laboratorioki aritaque iyoitanaquero maaroni quipatsiki iroperori avintarontsi.</p

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2–4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

    Genetic mechanisms of critical illness in COVID-19.

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    Host-mediated lung inflammation is present1, and drives mortality2, in the critical illness caused by coronavirus disease 2019 (COVID-19). Host genetic variants associated with critical illness may identify mechanistic targets for therapeutic development3. Here we report the results of the GenOMICC (Genetics Of Mortality In Critical Care) genome-wide association study in 2,244 critically ill patients with COVID-19 from 208 UK intensive care units. We have identified and replicated the following new genome-wide significant associations: on chromosome 12q24.13 (rs10735079, P = 1.65 × 10-8) in a gene cluster that encodes antiviral restriction enzyme activators (OAS1, OAS2 and OAS3); on chromosome 19p13.2 (rs74956615, P = 2.3 × 10-8) near the gene that encodes tyrosine kinase 2 (TYK2); on chromosome 19p13.3 (rs2109069, P = 3.98 ×  10-12) within the gene that encodes dipeptidyl peptidase 9 (DPP9); and on chromosome 21q22.1 (rs2236757, P = 4.99 × 10-8) in the interferon receptor gene IFNAR2. We identified potential targets for repurposing of licensed medications: using Mendelian randomization, we found evidence that low expression of IFNAR2, or high expression of TYK2, are associated with life-threatening disease; and transcriptome-wide association in lung tissue revealed that high expression of the monocyte-macrophage chemotactic receptor CCR2 is associated with severe COVID-19. Our results identify robust genetic signals relating to key host antiviral defence mechanisms and mediators of inflammatory organ damage in COVID-19. Both mechanisms may be amenable to targeted treatment with existing drugs. However, large-scale randomized clinical trials will be essential before any change to clinical practice

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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