Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Nat Immunol ; 14(9): 927-36, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23892723

RESUMEN

Mutations that result in loss of function of Nod2, an intracellular receptor for bacterial peptidoglycan, are associated with Crohn's disease. Here we found that the E3 ubiquitin ligase Pellino3 was an important mediator in the Nod2 signaling pathway. Pellino3-deficient mice had less induction of cytokines after engagement of Nod2 and had exacerbated disease in various experimental models of colitis. Furthermore, expression of Pellino3 was lower in the colons of patients with Crohn's disease. Pellino3 directly bound to the kinase RIP2 and catalyzed its ubiquitination. Loss of Pellino3 led to attenuation of Nod2-induced ubiquitination of RIP2 and less activation of the transcription factor NF-κB and mitogen-activated protein kinases (MAPKs). Our findings identify RIP2 as a substrate for Pellino3 and Pellino3 as an important mediator in the Nod2 pathway and regulator of intestinal inflammation.


Asunto(s)
Colitis/metabolismo , Proteína Adaptadora de Señalización NOD2/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Transducción de Señal , Ubiquitina-Proteína Ligasas/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Citrobacter rodentium/inmunología , Colitis/genética , Colitis/inmunología , Colitis/microbiología , Enfermedad de Crohn/genética , Enfermedad de Crohn/inmunología , Enfermedad de Crohn/metabolismo , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Humanos , Masculino , Ratones , Ratones Noqueados , Persona de Mediana Edad , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Proteína Serina-Treonina Quinasa 2 de Interacción con Receptor , Ubiquitina-Proteína Ligasas/química , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Adulto Joven
2.
Mol Biol Evol ; 40(11)2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-37948764

RESUMEN

Performing phylogenetic analysis with genome sequences maximizes the information used to estimate phylogenies and the resolution of closely related taxa. The use of single-nucleotide polymorphisms (SNPs) permits estimating trees without genome alignments and permits the use of data sets of hundreds of microbial genomes. kSNP4 is a program that identifies SNPs without using a reference genome, estimates parsimony, maximum likelihood, and neighbor-joining trees, and is able to annotate the discovered SNPs. kSNP4 is a command-line program that does not require any additional programs or dependencies to install or use. kSNP4 does not require any programming experience or bioinformatics experience to install and use. It is suitable for use by students through senior investigators. It includes a detailed user guide that explains all of the many features of kSNP4. In this study, we provide a detailed step-by-step protocol for downloading, installing, and using kSNP4 to build phylogenetic trees from genome sequences.


Asunto(s)
Biología Computacional , Evolución Molecular , Humanos , Filogenia
3.
Issues Ment Health Nurs ; 41(10): 887-898, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32497452

RESUMEN

This study explored the barriers that regulated nurse professionals encountered in recognizing and assessing geriatric depression in residential care facilities in the Canadian province of Alberta. The study used a convergent parallel mixed methods design, including a cross-sectional survey (N = 635) and qualitative interviews (N = 14) with regulated nurse professionals. Findings revealed six major barriers to the recognition of geriatric depression in Alberta, including 1) insufficient clinical knowledge and training in geriatric depression; 2) misconceived beliefs about geriatric depression; 3) limited access to resources; 4) unclear depression assessment protocol and procedures in facilities; 5) characteristics of models of care and organizational culture in facilities; and 6) communication difficulties among all stakeholders in the process. Socio-cultural values and beliefs about geriatric depression played a key role in the complex interaction of the various structural and agential barriers to the effective recognition and assessment of depression in residential care facilities in Alberta.


Asunto(s)
Depresión , Cultura Organizacional , Instituciones Residenciales , Anciano , Alberta , Estudios Transversales , Evaluación Geriátrica , Humanos , Enfermeras y Enfermeros
4.
Mol Biol Evol ; 34(12): 3303-3309, 2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-29029174

RESUMEN

Growth rates are an important tool in microbiology because they provide high throughput fitness measurements. The release of GrowthRates, a program that uses the output of plate reader files to automatically calculate growth rates, has facilitated experimental procedures in many areas. However, many sources of variation within replicate growth rate data exist and can decrease data reliability. We have developed a new statistical package, CompareGrowthRates (CGR), to enhance the program GrowthRates and accurately measure variation in growth rate data sets. We define a metric, Variability-score (V-score), that can help determine if variation within a data set might result in false interpretations. CGR also uses the bootstrap method to determine the fraction of bootstrap replicates in which a strain will grow the fastest. We illustrate the usage of CGR with growth rate data sets similar to those in Mira, Meza, et al. (Adaptive landscapes of resistance genes change as antibiotic concentrations change. Mol Biol Evol. 32(10): 2707-2715). These statistical methods are compatible with the analytic methods described in Growth Rates Made Easy and can be used with any set of growth rate output from GrowthRates.


Asunto(s)
Bacterias/crecimiento & desarrollo , Recuento de Colonia Microbiana/métodos , Recuento de Colonia Microbiana/estadística & datos numéricos , Biometría/métodos , Viabilidad Microbiana/genética , Reproducibilidad de los Resultados , Programas Informáticos
5.
J Adv Nurs ; 74(11): 2685-2700, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30019353

RESUMEN

AIMS: To report on the development and validation of the Moral Distress in Dementia Care Survey instrument. BACKGROUND: Despite growing awareness of moral distress among nurses, little is known about the moral distress experiences of nursing staff in dementia care settings. To address this gap, our research team developed a tool for measuring the frequency, severity and effects of moral distress in nursing staff working in dementia care. DESIGN: The research team employed an exploratory sequential mixed method design to generate items for the moral distress questionnaire. Data were collected between January 2013 - June 2014. In this paper, we report on the development and validation of the Moral Distress in Dementia Care Survey instrument. METHODS: The Moral Distress in Dementia Care Survey instrument was piloted with a portion of the target population prior to a broader implementation. Appropriate statistical analyses and psychometric testing were completed. RESULTS: The team collected 389 completed surveys from registered nurses, licensed practical nurses and healthcare aides, representing a 43.6% response rate across 23 sites. The Moral Distress in Dementia Care Survey emerged as a reliable and valid instrument to measure the frequency, severity and effects of moral distress for nursing staff in dementia care settings. The relative value of the Moral Distress in Dementia Care Survey as a measurement instrument was superseded by its clinical relevance for dementia care staff. CONCLUSION: The Moral Distress in Dementia Care Survey is a potentially useful tool for estimating the frequency, severity and effects of moral distress in nursing staff working in dementia care settings and for the evaluation of measures taken to mitigate moral distress.


Asunto(s)
Demencia/enfermería , Ética en Enfermería , Principios Morales , Atención de Enfermería/ética , Atención de Enfermería/psicología , Personal de Enfermería en Hospital/ética , Personal de Enfermería en Hospital/psicología , Adulto , Anciano , Anciano de 80 o más Años , Actitud del Personal de Salud , Canadá , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psicometría , Reproducibilidad de los Resultados , Estrés Psicológico , Encuestas y Cuestionarios
6.
J Clin Microbiol ; 55(7): 2143-2152, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28446577

RESUMEN

Strict infection control practices have been implemented for health care visits by cystic fibrosis (CF) patients in an attempt to prevent transmission of important pathogens. This study used whole-genome sequencing (WGS) to determine strain relatedness and assess population dynamics of Staphylococcus aureus isolates from a cohort of CF patients as assessed by strain relatedness. A total of 311 S. aureus isolates were collected from respiratory cultures of 115 CF patients during a 22-month study period. Whole-genome sequencing was performed, and using single nucleotide polymorphism (SNP) analysis, phylogenetic trees were assembled to determine relatedness between isolates. Methicillin-resistant Staphylococcus aureus (MRSA) phenotypes were predicted using PPFS2 and compared to the observed phenotype. The accumulation of SNPs in multiple isolates obtained over time from the same patient was examined to determine if a genomic molecular clock could be calculated. Pairs of isolates with ≤71 SNP differences were considered to be the "same" strain. All of the "same" strain isolates were either from the same patient or siblings pairs. There were 47 examples of patients being superinfected with an unrelated strain. The predicted MRSA phenotype was accurate in all but three isolates. Mutation rates were unable to be determined because the branching order in the phylogenetic tree was inconsistent with the order of isolation. The observation that transmissions were identified between sibling patients shows that WGS is an effective tool for determining transmission between patients. The observation that transmission only occurred between siblings suggests that Staphylococcus aureus acquisition in our CF population occurred outside the hospital environment and indicates that current infection prevention efforts appear effective.


Asunto(s)
Fibrosis Quística/complicaciones , Variación Genética , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Secuenciación Completa del Genoma , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Filogenia , Polimorfismo de Nucleótido Simple , Dinámica Poblacional , Staphylococcus aureus/aislamiento & purificación , Adulto Joven
7.
Bioinformatics ; 31(17): 2877-8, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-25913206

RESUMEN

UNLABELLED: We announce the release of kSNP3.0, a program for SNP identification and phylogenetic analysis without genome alignment or the requirement for reference genomes. kSNP3.0 is a significantly improved version of kSNP v2. AVAILABILITY AND IMPLEMENTATION: kSNP3.0 is implemented as a package of stand-alone executables for Linux and Mac OS X under the open-source BSD license. The executable packages, source code and a full User Guide are freely available at https://sourceforge.net/projects/ksnp/files/ CONTACT: barryghall@gmail.com.


Asunto(s)
Biología Computacional/métodos , Escherichia coli/genética , Genoma Bacteriano , Filogenia , Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ADN/métodos , Programas Informáticos , Bases de Datos de Ácidos Nucleicos , Escherichia coli/clasificación , Anotación de Secuencia Molecular
8.
Cladistics ; 32(1): 90-99, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34732024

RESUMEN

kSNP v2 is a powerful tool for single nucleotide polymorphism (SNP) identification from complete microbial genomes and for estimating phylogenetic trees from the identified SNPs. kSNP can analyse finished genomes, genome assemblies, raw reads or any combination of those and does not require either genome alignment or reference genomes. This study uses sequence evolution simulations to evaluate the topological accuracy of kSNP trees and to assess the effects of diversity and recombination on that accuracy. The accuracies of kSNP trees are strongly affected by increasing diversity, with parsimony accuracy > maximum-likelihood accuracy > neighbour-joining accuracy. Accuracy is also strongly influenced by recombination; as recombination increases accuracy decreases. Reliable trees are arbitrarily defined as those that have ≥ 90% topological accuracy. It is determined that the best predictor of topological accuracy is the ratio of r/m, a measure of the effect of recombination, to FCK (the fraction of core kmers), a measure of diversity. Tools are available to allow investigators to determine both r/m and FCK, and the relationship between topological accuracy and the ratio of r/m to FCK is determined. The practical implication of this study is that kSNP is an effective tool for estimating phylogenetic trees from microbial genome sequences provided that both recombination and sequence diversity are within acceptable ranges.

9.
Scand J Gastroenterol ; 51(4): 393-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26540240

RESUMEN

BACKGROUND: Small bowel angiodysplasias (SBA) account for 50% of obscure gastrointestinal bleeding. Lesions bleed recurrently and current treatments are relatively ineffective at reducing re-bleeding. Little is known about the natural history of SBA which is needed to guide treatment decisions and counsel patients on prognosis. AIM: The aim of this study is to describe the natural history of a cohort of patients with SBA. METHODS: Patients with SBA were identified retrospectively and clinical and outcome information were collected. Logistic regression analysis was performed to identify factors associated with re-bleeding. RESULTS: SBAs were found in 86 patients of which 54% (n = 47) were female, and the average age was 71.6 years. The majority (69%) had multiple lesions, mean of 2.76/patient, and 65% were located in the jejunum. Follow-up was available in 65% (n = 56). There was a significant increase in haemoglobin level from 10.05g/dL to 11.94g/dL, p < 0.001 after mean follow up of 31.9 (6-62) months. Re-bleeding events occurred in 80% (n = 45), with an average of 2.91/person. The mean interval between diagnosis and the first re-bleeding event was 10.7 months. Of the group overall, 70% (n = 40) required transfusions during follow up, and 67% required hospitalisation due to re-bleeding. About 50% received a directed treatment, including argon plasma coagulation, somatostatin analogues, or surgical resection. A total of 3.5% (n = 2) died as a direct consequence of bleeding from SBAs. Multiple lesions (p = 0.048) and valvular heart disease (p = 0.034) were predictive of re-bleeding. CONCLUSION: Our results show the significant impact of SBA on patients' morbidity, with high rates of re-bleeding, persistent anaemia and a mortality rate of 3.5%, despite the use of currently available medical and endoscopic therapies.


Asunto(s)
Angiodisplasia/diagnóstico , Enfermedades del Colon/diagnóstico , Intestino Delgado/irrigación sanguínea , Adulto , Anciano , Anciano de 80 o más Años , Angiodisplasia/terapia , Enfermedades del Colon/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
10.
Mol Biol Evol ; 31(1): 232-8, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24170494

RESUMEN

In the 1960s-1980s, determination of bacterial growth rates was an important tool in microbial genetics, biochemistry, molecular biology, and microbial physiology. The exciting technical developments of the 1990s and the 2000s eclipsed that tool; as a result, many investigators today lack experience with growth rate measurements. Recently, investigators in a number of areas have started to use measurements of bacterial growth rates for a variety of purposes. Those measurements have been greatly facilitated by the availability of microwell plate readers that permit the simultaneous measurements on up to 384 different cultures. Only the exponential (logarithmic) portions of the resulting growth curves are useful for determining growth rates, and manual determination of that portion and calculation of growth rates can be tedious for high-throughput purposes. Here, we introduce the program GrowthRates that uses plate reader output files to automatically determine the exponential portion of the curve and to automatically calculate the growth rate, the maximum culture density, and the duration of the growth lag phase. GrowthRates is freely available for Macintosh, Windows, and Linux. We discuss the effects of culture volume, the classical bacterial growth curve, and the differences between determinations in rich media and minimal (mineral salts) media. This protocol covers calibration of the plate reader, growth of culture inocula for both rich and minimal media, and experimental setup. As a guide to reliability, we report typical day-to-day variation in growth rates and variation within experiments with respect to position of wells within the plates.


Asunto(s)
Bacterias/crecimiento & desarrollo , Programas Informáticos , Algoritmos , Técnicas Bacteriológicas , Medios de Cultivo/química , Fenotipo , Reproducibilidad de los Resultados
11.
J Clin Gastroenterol ; 49(10): 831-6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25319741

RESUMEN

GOALS: To identify putative angiogenic factors associated with sporadic small bowel angiodysplasia (SBA). BACKGROUND: SBAs account for 50% of obscure gastrointestinal bleeding and due to delays in diagnosis and ineffective treatments, are associated with high levels of morbidity and mortality. Treatment development is impeded by a limited knowledge of the pathophysiology behind SBA formation. STUDY: We identified patients with definite sporadic SBA, and fecal immunochemical-negative controls were recruited from our institution's colorectal cancer screening program. Serum levels of VEGF, endoglin, Angiopoietin-2 (Ang-2), PDGF, Angiopoietin-1 (Ang-1), and TNF-α were measured using commercially available enzyme-linked immunosorbent assay kits. On the basis of serum results, we measured gene expression of target angiogenic factors in small bowel biopsy samples from angiodysplasias and unaffected tissue by quantitative PCR assessment. RESULTS: Serum samples were analyzed from 40 SBA patients and 40 controls. Median serum levels of Ang-2 were significantly higher in patients than controls with levels of Ang-1 and TNF-α significantly lower. There were no differences in serum levels of VEGF, endoglin, or PDGF. Gene expression levels of Ang-1, Ang-2, and their receptor Tie2 were all significantly higher in biopsies from areas of angiodysplasia compared with normal small bowel. CONCLUSIONS: This study, the first to explore the role of angiogenic factors in SBA, has identified a positive association between SBA and the Angiopoietin pathway, with increased serum and mucosal expression of Ang-2, which could potentially be used as a serum biomarker and future therapeutic target to improve outcome in affected patients.


Asunto(s)
Angiodisplasia/sangre , Inductores de la Angiogénesis/metabolismo , Enfermedades Intestinales/sangre , Intestino Delgado/irrigación sanguínea , Adulto , Anciano , Anciano de 80 o más Años , Angiodisplasia/complicaciones , Angiodisplasia/genética , Antígenos CD/sangre , Biopsia , Estudios de Casos y Controles , Endoglina , Ensayo de Inmunoadsorción Enzimática , Femenino , Hemorragia Gastrointestinal/sangre , Hemorragia Gastrointestinal/genética , Humanos , Enfermedades Intestinales/complicaciones , Enfermedades Intestinales/genética , Masculino , Persona de Mediana Edad , Factor de Crecimiento Derivado de Plaquetas/metabolismo , Receptor TIE-2/metabolismo , Receptores de Superficie Celular/sangre , Ribonucleasa Pancreática/sangre , Factor de Necrosis Tumoral alfa/sangre , Factor A de Crecimiento Endotelial Vascular/sangre , Proteínas de Transporte Vesicular/sangre
12.
Dig Dis ; 33(1): 42-51, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25531496

RESUMEN

An increasing understanding of the pathogenesis of Crohn's disease (CD), coupled with improvements in therapeutic options, has promoted the concept of stratifying patients with CD into distinct disease phenotypes according to risk. Small bowel CD, due to the numerous non-specific potential symptoms and the anatomical location of the disease, is a particularly difficult phenotype to identify. The fact that the majority of de novo strictures occur in the ileum/ileo-colonic region ensures that recognition of small bowel involvement is essential. Certainly, it is becoming increasingly recognised due to improvements in imaging and endoscopic techniques. Both CT and MR enterography appear capable of accurately diagnosing small bowel CD. Furthermore, the development of capsule endoscopy and balloon-assisted enteroscopy allow direct visualisation of the small bowel. Limited data to date would suggest that small bowel CD is a difficult entity to treat even in the current era of the ever-expanding field of biological therapies. Further long-term follow-up studies are necessary using both small bowel capsule endoscopy and cross-sectional imaging to truly assess, firstly, whether small bowel CD is more resistant to treatment and, secondly, whether it has an effect over time in terms of complications. In the future, serological and genetic tests, coupled with the aforementioned investigations, will permit early diagnosis and early treatment of small bowel CD.


Asunto(s)
Enfermedad de Crohn/patología , Intestino Delgado/patología , Biomarcadores/metabolismo , Enfermedad de Crohn/etiología , Enfermedad de Crohn/genética , Enfermedad de Crohn/terapia , Humanos , Fenotipo
13.
Mol Biol Evol ; 30(5): 1229-35, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23486614

RESUMEN

Phylogenetic analysis is sometimes regarded as being an intimidating, complex process that requires expertise and years of experience. In fact, it is a fairly straightforward process that can be learned quickly and applied effectively. This Protocol describes the several steps required to produce a phylogenetic tree from molecular data for novices. In the example illustrated here, the program MEGA is used to implement all those steps, thereby eliminating the need to learn several programs, and to deal with multiple file formats from one step to another (Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S. 2011. MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol. 28:2731-2739). The first step, identification of a set of homologous sequences and downloading those sequences, is implemented by MEGA's own browser built on top of the Google Chrome toolkit. For the second step, alignment of those sequences, MEGA offers two different algorithms: ClustalW and MUSCLE. For the third step, construction of a phylogenetic tree from the aligned sequences, MEGA offers many different methods. Here we illustrate the maximum likelihood method, beginning with MEGA's Models feature, which permits selecting the most suitable substitution model. Finally, MEGA provides a powerful and flexible interface for the final step, actually drawing the tree for publication. Here a step-by-step protocol is presented in sufficient detail to allow a novice to start with a sequence of interest and to build a publication-quality tree illustrating the evolution of an appropriate set of homologs of that sequence. MEGA is available for use on PCs and Macs from www.megasoftware.net.


Asunto(s)
Evolución Molecular , Filogenia , Programas Informáticos , Algoritmos , Internet
14.
Scand J Gastroenterol ; 49(11): 1275-84, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25260016

RESUMEN

BACKGROUND: The development of capsule technology has modified our approach to the diagnosis of gastrointestinal disease. The relatively rapid uptake of capsule endoscopy as an important clinical tool can be largely ascribed to a number of key factors, including the fact that it is a relatively easy examination to perform in an outpatient setting. It has been established as an integral part of the investigation pathway for obscure gastrointestinal bleeding and suspected small bowel Crohn's disease (CD). CURRENT USE OF CAPSULE ENDOSCOPY: Small bowel CD can be a challenging entity to diagnose. Capsule endoscopy has been shown to be both useful and safe in patients with both suspected and established small bowel CD. In suspected disease, capsule endoscopy has both a high diagnostic yield and negative predictive value. Capsule findings lead to changes in management in up to 73% of patients with established CD. However, while the technology appears capable of detecting subtle mucosal changes not readily apparent on alternate imaging modalities, the question of what actually constitutes small bowel CD as described by capsule is an issue that remains unresolved to date. Thus, capsule endoscopy is best utilised in tandem with advanced imaging and endoscopic techniques such as balloon- assisted enteroscopy. FUTURE DEVELOPMENTS: The development of a capsule capable of viewing the colon coupled with improvements in image quality and battery life are likely to lead to the increasing uptake of this technology. In the future, 'interactive' capsules with the ability to view the entire gastrointestinal tract may be a reality.


Asunto(s)
Endoscopía Capsular/tendencias , Enfermedad de Crohn/diagnóstico , Humanos , Reproducibilidad de los Resultados
15.
Scand J Gastroenterol ; 48(4): 433-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23356721

RESUMEN

OBJECTIVE: Gastrointestinal angiodysplasias recurrently bleed, accounting for 3-5% of obscure gastrointestinal bleeding. The advent of small bowel capsule endoscopy (SBCE) has led to an increased recognition of small bowel angiodysplasias (SBAs) but little is known about their etiology. Previous small cohorts and case reports suggest an equal gender incidence and associations with cardiovascular disease, renal impairment, and coagulopathies. METHODS: Patients with SBA were identified from our SBCE database. A control group, in whom gastrointestinal bleeding had been excluded, was also identified. Information on patient demographics, past medical/surgical/social history and medications was prospectively obtained. RESULTS: A total of 82 patients and 95 controls were identified. Data was available from 81% (n = 66) of SBA patients. The mean age of patients and controls was 66.9 years (35-90) and 69.2 years (54-77), and 60% (n = 40) and 58% (n = 55) were females, respectively. There was a higher rate of all comorbidities in the SBA group 92% (61/66) versus controls 76% (72/95) p < 0.002. Significant associations were found with: hypertension (odds ratio [OR] 2.8), ischemic heart disease (OR 4.25), arrhythmias (OR 4.36), valvular heart disease (OR 18), congestive heart failure (OR 4.22), chronic kidney disease (CKD) (OR 8.4), chronic respiratory conditions (OR 2.0), and previous venous thromboembolism (VTE) (OR 6.4). Anticoagulant use was higher in patients with SBA, 50% (n = 33) versus 27% (n = 26) of controls, p < 0.002, specifically warfarin and asasantin retard. CONCLUSIONS: SBA occurs in elderly patients with cardiovascular disease and CKD, as previously suggested. This study identifies a previously unrecognised risk in females, patients with chronic respiratory conditions and VTE, and the use of warfarin and asasantin retard. These associations should raise awareness of possible underlying SBA in risk patients with anemia.


Asunto(s)
Angiodisplasia/complicaciones , Intestino Delgado , Adulto , Anciano , Anciano de 80 o más Años , Angiodisplasia/diagnóstico , Angiodisplasia/tratamiento farmacológico , Angiodisplasia/epidemiología , Anticoagulantes/uso terapéutico , Arritmias Cardíacas/complicaciones , Endoscopía Capsular/métodos , Estudios de Casos y Controles , Estudios de Cohortes , Diagnóstico Precoz , Femenino , Insuficiencia Cardíaca/complicaciones , Enfermedades de las Válvulas Cardíacas/complicaciones , Humanos , Hipertensión/complicaciones , Incidencia , Intestino Delgado/diagnóstico por imagen , Intestino Delgado/patología , Irlanda/epidemiología , Fallo Renal Crónico/complicaciones , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Estudios Prospectivos , Enfermedades Respiratorias/complicaciones , Factores de Riesgo , Encuestas y Cuestionarios , Ultrasonografía , Tromboembolia Venosa/complicaciones
16.
J Bacteriol ; 194(15): 3922-37, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22609915

RESUMEN

Gardnerella vaginalis is associated with a spectrum of clinical conditions, suggesting high degrees of genetic heterogeneity among stains. Seventeen G. vaginalis isolates were subjected to a battery of comparative genomic analyses to determine their level of relatedness. For each measure, the degree of difference among the G. vaginalis strains was the highest observed among 23 pathogenic bacterial species for which at least eight genomes are available. Genome sizes ranged from 1.491 to 1.716 Mb; GC contents ranged from 41.18% to 43.40%; and the core genome, consisting of only 746 genes, makes up only 51.6% of each strain's genome on average and accounts for only 27% of the species supragenome. Neighbor-grouping analyses, using both distributed gene possession data and core gene allelic data, each identified two major sets of strains, each of which is composed of two groups. Each of the four groups has its own characteristic genome size, GC ratio, and greatly expanded core gene content, making the genomic diversity of each group within the range for other bacterial species. To test whether these 4 groups corresponded to genetically isolated clades, we inferred the phylogeny of each distributed gene that was present in at least two strains and absent in at least two strains; this analysis identified frequent homologous recombination within groups but not between groups or sets. G. vaginalis appears to include four nonrecombining groups/clades of organisms with distinct gene pools and genomic properties, which may confer distinct ecological properties. Consequently, it may be appropriate to treat these four groups as separate species.


Asunto(s)
Infecciones Bacterianas/microbiología , ADN Bacteriano/genética , Gardnerella vaginalis/clasificación , Gardnerella vaginalis/genética , Genoma Bacteriano , Polimorfismo Genético , Composición de Base , Análisis por Conglomerados , ADN Bacteriano/química , Gardnerella vaginalis/aislamiento & purificación , Genes Bacterianos , Genotipo , Humanos , Datos de Secuencia Molecular , Filogenia , Análisis de Secuencia de ADN
17.
PLoS One ; 17(10): e0276040, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36228033

RESUMEN

The spectrophotometer has been used for decades to measure the density of bacterial populations as the turbidity expressed as optical density-OD. However, the OD alone is an unreliable metric and is only proportionately accurate to cell titers to about an OD of 0.1. The relationship between OD and cell titer depends on the configuration of the spectrophotometer, the length of the light path through the culture, the size of the bacterial cells, and the cell culture density. We demonstrate the importance of plate reader calibration to identify the exact relationship between OD and cells/mL. We use four bacterial genera and two sizes of micro-titer plates (96-well and 384-well) to show that the cell/ml per unit OD depends heavily on the bacterial cell size and plate size. We applied our calibration curve to real growth curve data and conclude the cells/mL-rather than OD-is a metric that can be used to directly compare results across experiments, labs, instruments, and species.


Asunto(s)
Bacterias , Espectrofotometría/métodos
18.
BMC Genomics ; 12: 187, 2011 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-21489287

RESUMEN

BACKGROUND: Staphylococcus aureus is associated with a spectrum of symbiotic relationships with its human host from carriage to sepsis and is frequently associated with nosocomial and community-acquired infections, thus the differential gene content among strains is of interest. RESULTS: We sequenced three clinical strains and combined these data with 13 publically available human isolates and one bovine strain for comparative genomic analyses. All genomes were annotated using RAST, and then their gene similarities and differences were delineated. Gene clustering yielded 3,155 orthologous gene clusters, of which 2,266 were core, 755 were distributed, and 134 were unique. Individual genomes contained between 2,524 and 2,648 genes. Gene-content comparisons among all possible S. aureus strain pairs (n = 136) revealed a mean difference of 296 genes and a maximum difference of 476 genes. We developed a revised version of our finite supragenome model to estimate the size of the S. aureus supragenome (3,221 genes, with 2,245 core genes), and compared it with those of Haemophilus influenzae and Streptococcus pneumoniae. There was excellent agreement between RAST's annotations and our CDS clustering procedure providing for high fidelity metabolomic subsystem analyses to extend our comparative genomic characterization of these strains. CONCLUSIONS: Using a multi-species comparative supragenomic analysis enabled by an improved version of our finite supragenome model we provide data and an interpretation explaining the relatively larger core genome of S. aureus compared to other opportunistic nasopharyngeal pathogens. In addition, we provide independent validation for the efficiency and effectiveness of our orthologous gene clustering algorithm.


Asunto(s)
Genoma Bacteriano , Haemophilus influenzae/genética , Staphylococcus aureus/genética , Streptococcus pneumoniae/genética , Algoritmos , Animales , Bovinos , Regulación Bacteriana de la Expresión Génica , Haemophilus influenzae/aislamiento & purificación , Humanos , Modelos Genéticos , Familia de Multigenes , Sistemas de Lectura Abierta , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/aislamiento & purificación , Streptococcus pneumoniae/aislamiento & purificación
19.
J Clin Microbiol ; 49(10): 3568-75, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21849692

RESUMEN

Minimum spanning trees (MSTs) are frequently used in molecular epidemiology research to estimate relationships among individual strains or isolates. Nevertheless, there are significant caveats to MST algorithms that have been largely ignored in molecular epidemiology studies and that have the potential to confound or alter the interpretation of the results of those analyses. Specifically, (i) presenting a single, arbitrarily selected MST illustrates only one of potentially many equally optimal solutions, and (ii) statistical metrics are not used to assess the credibility of MST estimations. Here, we survey published MSTs previously used to infer microbial population structure in order to determine the effect of these factors. We propose a technique to estimate the number of alternative MSTs for a data set and find that multiple MSTs exist for each case in our survey. By implementing a bootstrapping metric to evaluate the reliability of alternative MST solutions, we discover that they encompass a wide range of credibility values. On the basis of these observations, we conclude that current approaches to studying population structure using MSTs are inadequate. We instead propose a systematic approach to MST estimation that bases analyses on the optimal computation of an input distance matrix, provides information about the number and configurations of alternative MSTs, and allows identification of the most credible MST or MSTs by using a bootstrapping metric. It is our hope this algorithm will become the new "gold standard" approach for analyzing MSTs for molecular epidemiology so that this generally useful computational approach can be used informatively and to its full potential.


Asunto(s)
Tipificación Molecular/métodos , Polimorfismo Genético , Análisis por Conglomerados , Genotipo , Humanos , Epidemiología Molecular/métodos
20.
Rural Remote Health ; 11(3): 1716, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21827218

RESUMEN

INTRODUCTION: The public health system must consider violence as an all too common reality in modern life. Violence can contribute to long-lasting negative consequences for individuals and communities. Research on violence has primarily focused on urban environments. Research examining youth violence within rural communities is limited. This is particularly the case for the links between gender and violence in small rural settings. The purpose of this study was to examine rural violence from a gender perspective by examining four variables: meaning, causes, consequences and solutions. METHODS: A survey was completed in Central Alberta, Canada with 178 students from grades 6 to 12. The schools' geographic locations represented two distinct economic settings: one natural resources and the other agriculture. The mean age of the participants was 16 years with 60% of the youth female and 40% male. The survey instrument was composed of demographic questions and 70 questions that focused on violence. RESULTS: Violence was a concern for all youth, but there were gender differences. Females viewed the meaning of violence as having the intent to harm others and causes contributing to violence included television, movies, video games and the internet. Females were more concerned than males about the emotional consequences of violence. For solutions, females were more accepting of intrusive means to control violence such as increased security and stricter school rules, and involving non-peer helpers such as teachers and community based agencies as a means to help combat violence. CONCLUSIONS: The results of this study indicate that violence exists among rural youth and causes a great deal of concern. In particular, the study underscores the fact that there are potential gender differences in relation to causes, meaning, impact and solutions to violence. All the youth believed that violence in their lives needs to be addressed and want to develop anti-violence strategies. Females in particular see the development of such programs including youth themselves and community partners.


Asunto(s)
Violencia/estadística & datos numéricos , Adolescente , Alberta , Niño , Recolección de Datos , Femenino , Humanos , Masculino , Población Rural , Factores Sexuales , Violencia/prevención & control , Violencia/psicología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA