Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
Más filtros

Colección BVS Ecuador
Intervalo de año de publicación
1.
Bioinformatics ; 40(Supplement_1): i401-i409, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38940168

RESUMEN

Automated protein function prediction is a crucial and widely studied problem in bioinformatics. Computationally, protein function is a multilabel classification problem where only positive samples are defined and there is a large number of unlabeled annotations. Most existing methods rely on the assumption that the unlabeled set of protein function annotations are negatives, inducing the false negative issue, where potential positive samples are trained as negatives. We introduce a novel approach named PU-GO, wherein we address function prediction as a positive-unlabeled ranking problem. We apply empirical risk minimization, i.e. we minimize the classification risk of a classifier where class priors are obtained from the Gene Ontology hierarchical structure. We show that our approach is more robust than other state-of-the-art methods on similarity-based and time-based benchmark datasets. AVAILABILITY AND IMPLEMENTATION: Data and code are available at https://github.com/bio-ontology-research-group/PU-GO.


Asunto(s)
Biología Computacional , Ontología de Genes , Proteínas , Proteínas/química , Proteínas/metabolismo , Biología Computacional/métodos , Bases de Datos de Proteínas , Algoritmos
2.
Bioinformatics ; 40(5)2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38696757

RESUMEN

MOTIVATION: Whole-exome and genome sequencing have become common tools in diagnosing patients with rare diseases. Despite their success, this approach leaves many patients undiagnosed. A common argument is that more disease variants still await discovery, or the novelty of disease phenotypes results from a combination of variants in multiple disease-related genes. Interpreting the phenotypic consequences of genomic variants relies on information about gene functions, gene expression, physiology, and other genomic features. Phenotype-based methods to identify variants involved in genetic diseases combine molecular features with prior knowledge about the phenotypic consequences of altering gene functions. While phenotype-based methods have been successfully applied to prioritizing variants, such methods are based on known gene-disease or gene-phenotype associations as training data and are applicable to genes that have phenotypes associated, thereby limiting their scope. In addition, phenotypes are not assigned uniformly by different clinicians, and phenotype-based methods need to account for this variability. RESULTS: We developed an Embedding-based Phenotype Variant Predictor (EmbedPVP), a computational method to prioritize variants involved in genetic diseases by combining genomic information and clinical phenotypes. EmbedPVP leverages a large amount of background knowledge from human and model organisms about molecular mechanisms through which abnormal phenotypes may arise. Specifically, EmbedPVP incorporates phenotypes linked to genes, functions of gene products, and the anatomical site of gene expression, and systematically relates them to their phenotypic effects through neuro-symbolic, knowledge-enhanced machine learning. We demonstrate EmbedPVP's efficacy on a large set of synthetic genomes and genomes matched with clinical information. AVAILABILITY AND IMPLEMENTATION: EmbedPVP and all evaluation experiments are freely available at https://github.com/bio-ontology-research-group/EmbedPVP.


Asunto(s)
Genómica , Humanos , Genómica/métodos , Fenotipo , Variación Genética , Biología Computacional/métodos , Aprendizaje Automático
3.
Bioinformatics ; 39(1)2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36534832

RESUMEN

MOTIVATION: Ontologies contain formal and structured information about a domain and are widely used in bioinformatics for annotation and integration of data. Several methods use ontologies to provide background knowledge in machine learning tasks, which is of particular importance in bioinformatics. These methods rely on a set of common primitives that are not readily available in a software library; a library providing these primitives would facilitate the use of current machine learning methods with ontologies and the development of novel methods for other ontology-based biomedical applications. RESULTS: We developed mOWL, a Python library for machine learning with ontologies formalized in the Web Ontology Language (OWL). mOWL implements ontology embedding methods that map information contained in formal knowledge bases and ontologies into vector spaces while preserving some of the properties and relations in ontologies, as well as methods to use these embeddings for similarity computation, deductive inference and zero-shot learning. We demonstrate mOWL on the knowledge-based prediction of protein-protein interactions using the gene ontology and gene-disease associations using phenotype ontologies. AVAILABILITY AND IMPLEMENTATION: mOWL is freely available on https://github.com/bio-ontology-research-group/mowl and as a Python package in PyPi. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Ontologías Biológicas , Ontología de Genes , Bases del Conocimiento , Programas Informáticos , Aprendizaje Automático
4.
Nucleic Acids Res ; 49(W1): W140-W146, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34019664

RESUMEN

Understanding the functions of proteins is crucial to understand biological processes on a molecular level. Many more protein sequences are available than can be investigated experimentally. DeepGOPlus is a protein function prediction method based on deep learning and sequence similarity. DeepGOWeb makes the prediction model available through a website, an API, and through the SPARQL query language for interoperability with databases that rely on Semantic Web technologies. DeepGOWeb provides accurate and fast predictions and ensures that predicted functions are consistent with the Gene Ontology; it can provide predictions for any protein and any function in Gene Ontology. DeepGOWeb is freely available at https://deepgo.cbrc.kaust.edu.sa/.


Asunto(s)
Proteínas/fisiología , Análisis de Secuencia de Proteína/métodos , Programas Informáticos , Aprendizaje Profundo , Ontología de Genes , Internet , Proteínas/química , Proteínas/genética
5.
Int J Mol Sci ; 24(16)2023 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-37629140

RESUMEN

We assessed whether allicin, through its antihypertensive and antioxidant effects, relieves vascular remodeling, endothelial function, and oxidative stress (OS), thereby improving experimental pulmonary arterial hypertension (PAH). Allicin (16 mg/kg) was administered to rats with PAH (monocrotaline 60 mg/kg). Allicin encouraged body weight gain and survival rate, and medial wall thickness and the right ventricle (RV) hypertrophy were prevented. Also, angiotensin II concentrations in the lung (0.37 ± 0.01 vs. 0.47 ± 0.06 pmoles/mL, allicin and control, respectively) and plasma (0.57 ± 0.05 vs. 0.75 ± 0.064, allicin and control respectively) and the expressions of angiotensin-converting enzyme II and angiotensin II type 1 receptor in lung tissue were maintained at normal control levels with allicin. In PAH rats treated with allicin, nitric oxide (NO) (31.72 ± 1.22 and 51.4 ± 3.45 pmoles/mL), tetrahydrobiopterin (8.43 ± 0.33 and 10.14 ± 0.70 pmoles/mL), cyclic guanosine monophosphate (5.54 ± 0.42 and 5.64 ± 0.73 pmoles/mL), and Ang-(1-7) (0.88 ± 0.23 and 0.83 ± 0.056 pmoles/mL) concentrations increased in lung tissue and plasma, respectively. In contrast, dihydrobiopterin increase was prevented in both lung tissue and plasma (5.75 ± 0.3 and 5.64 ± 0.73 pmoles/mL); meanwhile, phosphodiesterase-5 was maintained at normal levels in lung tissue. OS in PAH was prevented with allicin through the increased expression of Nrf2 in the lung. Allicin prevented the lung response to hypoxia, preventing the overexpression of HIF-1α and VEGF. Allicin attenuated the vascular remodeling and RV hypertrophy in PAH through its effects on NO-dependent vasodilation, modulation of RAS, and amelioration of OS. Also, these effects could be associated with the modulation of HIF-1α and improved lung oxygenation. The global effects of allicin contribute to preventing endothelial dysfunction, remodeling of the pulmonary arteries, and RV hypertrophy, preventing heart failure, thus favoring survival. Although human studies are needed, the data suggest that, alone or in combination therapy, allicin may be an alternative in treating PAH if we consider that, similarly to current treatments, it improves lung vasodilation and increase survival. Allicin may be considered an option when there is a lack of efficacy, and where drug intolerance is observed, to enhance the efficacy of drugs, or when more than one pathogenic mechanism must be addressed.


Asunto(s)
Hipertensión Arterial Pulmonar , Humanos , Animales , Ratas , Remodelación Vascular , Hipertensión Pulmonar Primaria Familiar , Hipertrofia
6.
J Antimicrob Chemother ; 77(4): 1045-1051, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-35045160

RESUMEN

BACKGROUND: Surveillance studies including antibiotic resistance and evolution of pneumococcal serotypes are critical to evaluate the susceptibility of commonly used antibiotics and the contribution of conjugate vaccines against resistant strains. OBJECTIVES: To determine the susceptibility of clinical isolates of Streptococcus pneumoniae with reduced susceptibility to penicillin to a panel of antibiotics during the period 2004-20 and characterize the impact of pneumococcal conjugate vaccines in the evolution of resistant serotypes. METHODS: We selected 3017 clinical isolates in order to determine the minimal inhibitory concentration to penicillin, amoxicillin, cefotaxime, erythromycin, levofloxacin and oral cephalosporins, including cefditoren, cefixime and cefpodoxime. RESULTS: The antibiotics with the lowest proportion of resistant strains from 2004 to 2020 were cefditoren (<0.4%), followed by cefotaxime (<5%), penicillin (<6.5%) and levofloxacin (<7%). Among oral cephalosporins, cefixime was the cephalosporin with the highest MIC90 (32 mg/L) and MIC50 (8-16 mg/L) throughout the study, followed by cefpodoxime with highest values of MIC90 (4 mg/L) and MIC50 (2 mg/L) for the majority of the study period. In contrast, cefditoren was the cephalosporin with the lowest MIC90 (1 mg/L) and MIC50 (0.25-0.5 mg/L). CONCLUSIONS: Cefditoren was the antibiotic with the highest proportion of susceptible strains. Hence, more than 80% of the clinical strains were susceptible to cefditoren throughout the period 2004-20. The proportion of resistant isolates to cefditoren and cefotaxime was scarce, being less than 0.4% for cefditoren and lower than 5% for cefotaxime, despite the increased rates of serotypes not covered by the 13-valent pneumococcal conjugate vaccine.


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Antibacterianos/farmacología , Cefalosporinas/farmacología , Humanos , Estudios Longitudinales , Pruebas de Sensibilidad Microbiana , Infecciones Neumocócicas/epidemiología , España/epidemiología
7.
PLoS Pathog ; 16(4): e1008404, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32240273

RESUMEN

Among infectious diseases, tuberculosis is the leading cause of death worldwide, and represents a serious threat, especially in developing countries. The protective effects of Bacillus Calmette-Guerin (BCG), the current vaccine against tuberculosis, have been related not only to specific induction of T-cell immunity, but also with the long-term epigenetic and metabolic reprogramming of the cells from the innate immune system through a process termed trained immunity. Here we show that MTBVAC, a live attenuated strain of Mycobacterium tuberculosis, safe and immunogenic against tuberculosis antigens in adults and newborns, is also able to generate trained immunity through the induction of glycolysis and glutaminolysis and the accumulation of histone methylation marks at the promoters of proinflammatory genes, facilitating an enhanced response after secondary challenge with non-related bacterial stimuli. Importantly, these findings in human primary myeloid cells are complemented by a strong MTBVAC-induced heterologous protection against a lethal challenge with Streptococcus pneumoniae in an experimental murine model of pneumonia.


Asunto(s)
Modelos Animales de Enfermedad , Inmunidad Innata/inmunología , Monocitos/inmunología , Mycobacterium tuberculosis/inmunología , Neumonía/prevención & control , Vacunas contra la Tuberculosis/administración & dosificación , Tuberculosis/prevención & control , Animales , Vacuna BCG/administración & dosificación , Vacuna BCG/inmunología , Células Cultivadas , Reprogramación Celular , Femenino , Humanos , Inmunidad Innata/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Mycobacterium tuberculosis/efectos de los fármacos , Neumonía/inmunología , Neumonía/microbiología , Tuberculosis/inmunología , Tuberculosis/microbiología , Vacunación
8.
Clin Infect Dis ; 73(11): e3778-e3787, 2021 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-32990303

RESUMEN

BACKGROUND: Introduction of pneumococcal conjugate vaccines (PCVs) has reduced the disease caused by vaccine serotypes in children, providing herd protection to adults. However, the emergence of nonvaccine serotypes is of great concern worldwide. METHODS: This study includes national laboratory data from invasive pneumococcal disease (IPD) cases that affected pediatric and adult populations during 2009-2019. The impact of implementing different vaccine strategies for immunocompetent adults by comparing Spanish regions that used the 13-valent PCV (PCV13) vs regions that used the 23-valent pneumococcal polysaccharide vaccine (PPV23) was also analyzed for 2017-2019. RESULTS: The overall reductions in IPD cases by PCV13 serotypes in children and adults were 88% and 59%, respectively, during 2009-2019, with a constant increase in serotype 8 in adults since 2015. IPD cases by additional serotypes covered by PPV23 increased from 20% in 2009 to 52% in 2019. In children, serotype 24F was the most frequent in 2019, whereas serotypes 3 and 8 accounted for 36% of IPD cases in adults. Introduction of PCV13 or PPV23 in the adult calendar of certain Spanish regions reduced the IPD cases by PCV13 serotypes by up to 25% and 11%, respectively, showing a decrease of serotype 3 when PCV13 was used. CONCLUSIONS: Use of PCV13 in children has affected the epidemiology, reducing the burden of IPD in children but also in adults by herd protection; however, the increase in serotype 8 in adults is worrisome. Vaccination with PCV13 in adults seems to control IPD cases by PCV13 serotypes including serotype 3.


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Adulto , Niño , Humanos , Incidencia , Lactante , Infecciones Neumocócicas/epidemiología , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas , Serogrupo , España/epidemiología , Vacunas Conjugadas
9.
Int J Obes (Lond) ; 45(8): 1687-1695, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34083744

RESUMEN

BACKGROUND: Extended-release naltrexone/bupropion (NB) is indicated for chronic weight management. Incretin agents are recommended for patients with type 2 diabetes. This analysis looked at the add-on of NB to incretins to see if weight loss could occur in patients already stabilized on incretin agents. METHODS: This was a post-hoc analysis of NB vs. placebo (PL) among subjects with type 2 diabetes stable on an incretin agent prior to randomization in a double-blind, PL-controlled cardiovascular outcome trial (N = 1317). RESULTS: Over 1 year, mean weight loss was significantly greater among NB patients vs. PL among those taking DPP-4i (mean absolute difference 4.6% [p < 0.0001]) and those taking GLP-1RAs (mean absolute difference 5.2%, p < 0.0001). Proportions of subjects achieving 5% weight loss were significantly greater for NB vs. PL at weeks 26 and 52 among those taking DPP-4is or GLP-1RAs. There were no significant differences in effectiveness observed between NB + DPP-4i and NB + GLP-1RA or between PL + DPP-4i and PL + GLP-1RA in any of the analyses. Serious adverse events were reported by 9.1% and 11.1% for PL + DPP-4i and PL + GLP-1RA, respectively, and 13.3% and 12.4% of NB + DPP-4i and NB + GLP-1RA, respectively. CONCLUSION: NB appears to be effective in reducing weight in patients with T2DM and obesity/overweight who are taking DPP-4ihibitors or GLP-1RA. The SAE rates in all arms of this analysis were lower than have been reported in other cardiovascular outcome trials in type 2 diabetes.


Asunto(s)
Fármacos Antiobesidad , Bupropión , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Incretinas/uso terapéutico , Naltrexona , Anciano , Fármacos Antiobesidad/efectos adversos , Fármacos Antiobesidad/farmacología , Fármacos Antiobesidad/uso terapéutico , Peso Corporal/efectos de los fármacos , Bupropión/efectos adversos , Bupropión/farmacología , Bupropión/uso terapéutico , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Humanos , Hipoglucemiantes/uso terapéutico , Masculino , Persona de Mediana Edad , Naltrexona/efectos adversos , Naltrexona/farmacología , Naltrexona/uso terapéutico , Obesidad/complicaciones , Obesidad/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto , Pérdida de Peso/efectos de los fármacos
10.
Diabetes Obes Metab ; 23(3): 861-865, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33275326

RESUMEN

Sustained weight loss improves liver histology in non-alcoholic fatty liver disease. This post hoc analysis of four phase III, 56-week, randomized controlled trials investigated if extended-release naltrexone and bupropion (NB) affects alanine aminotransferase (ALT) and Fibrosis-4 (FIB-4) index in adults with overweight or obesity. Two thousand and seventy-three subjects (NB = 1310; placebo = 763; 79.0% female; 81.6% Caucasian) had baseline mean weight 101 kg, body mass index 36.2 kg/m2 , ALT 26.9 IU/L and FIB-4 0.79. At 56 weeks, NB-treated subjects experienced more weight loss than placebo (8.7 vs. 3.2 kg, respectively, P < .0001). Weight loss, independent of treatment, was associated with improved ALT and FIB-4 (P < .0001). There was a significant independent effect of NB on change from baseline for FIB-4 (P < .0001), but not for ALT (P = .54). Categorical ALT response (from above to within normal ranges: 10-40 IU/L for men; 7-35 IU/L for women) and achievement of 25% and 50% reduction in ALT were greater for NB versus placebo, and independently affected by weight loss (P < .0001), but not treatment. NB-associated weight loss may improve liver health by normalizing ALT values for those with high baseline levels.


Asunto(s)
Naltrexona , Enfermedad del Hígado Graso no Alcohólico , Adulto , Alanina Transaminasa , Bupropión/uso terapéutico , Método Doble Ciego , Femenino , Humanos , Hígado , Masculino , Naltrexona/uso terapéutico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto
11.
Diabetes Obes Metab ; 21(3): 691-699, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30393961

RESUMEN

AIM: There is limited information concerning the effects of canagliflozin (CANA), a sodium-glucose co-transporter 2 inhibitor (SGLT2i) in a real-world clinical setting in Canada. CanCARE is a 12-month, prospective, observational analysis to demonstrate the effectiveness and safety of CANA in usual clinical practice in Canada. MATERIALS AND METHODS: SGLT2i-naïve adult patients with type 2 diabetes mellitus (T2DM) (n = 527) on a stable antihyperglycemic agent (AHA) regimen with glycated hemoglobin (A1C) ≥ 7%, an estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m2 , were initiated on CANA as part of their usual treatment approach, and were followed for a period of 12 months. The primary effectiveness objective was the mean change in HbA1c from baseline to 6 and 12 months. RESULTS: Significant improvement from baseline in mean HbA1c levels were observed at 6 months (-0.90%; 95% CI, -1.02, -0.78) and at 12 months (-1.04%; 95% CI, -1.15, -0.92), regardless of duration of diabetes or background AHA treatment regimen. Similarly, significant decreases in systolic blood pressure (-4.65 mm Hg); body weight (-3.24 kg), waist circumference (-2.91 cm) and body mass index (-1.15 kg/m2 ) were observed at 12 months. Additionally, 40.5% of patients achieved the double endpoint (≥0.5% HbA1c reduction and ≥ 3% weight loss), while 24.3% of patients achieved the triple composite endpoint (≥0.5% HbA1c reduction, ≥3% weight loss and ≥ 4 mm Hg systolic blood pressure reduction). No unexpected adverse events were reported. CONCLUSION: CANA provided sustained clinically meaningful improvements in cardiometabolic parameters in this study in a real-world setting, confirming findings from randomized controlled trials.


Asunto(s)
Canagliflozina/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Adulto , Anciano , Canadá , Canagliflozina/efectos adversos , Diabetes Mellitus Tipo 2/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Registros Electrónicos de Salud/estadística & datos numéricos , Femenino , Medicina General/estadística & datos numéricos , Humanos , Masculino , Persona de Mediana Edad , Sistema de Registros , Resultado del Tratamiento
12.
Artículo en Inglés | MEDLINE | ID: mdl-29581113

RESUMEN

Bacteriophage-borne lytic enzymes, also named lysins or enzybiotics, are efficient agents for the killing of bacterial pathogens. The colonization of the respiratory tract by Streptococcus pneumoniae is a prerequisite for the establishment of the infection process. Hence, we have evaluated the antibacterial activities of three different lysins against pneumococcal colonization using human nasopharyngeal and lung epithelial cells as well as a mouse model of nasopharyngeal colonization. The lysins tested were the wild-type Cpl-1, the engineered Cpl-7S, and the chimera Cpl-711. Moreover, we included amoxicillin as a comparator antibiotic. Human epithelial cells were infected with three different multidrug-resistant clinical isolates of S. pneumoniae followed by a single dose of the corresponding lysin. The antimicrobial activities of these lysins were also evaluated using a mouse nasopharyngeal carriage model. The exposure of the infected epithelial cells to Cpl-7S did not result in the killing of any of the pneumococcal strains investigated. However, the treatment with Cpl-1 or Cpl-711 increased the killing of S. pneumoniae organisms adhered to both types of human epithelial cells, with Cpl-711 being more effective than Cpl-1, at subinhibitory concentrations. In addition, a treatment with amoxicillin had no effect on reducing the carrier state, whereas mice treated by the intranasal route with Cpl-711 showed significantly reduced nasopharyngeal colonization, with no detection of bacterial load in 20 to 40% of the mice. This study indicates that Cpl-1 and Cpl-711 lysins might be promising antimicrobial candidates for therapy against pneumococcal colonization.


Asunto(s)
Antibacterianos/farmacología , Enfermedades Nasofaríngeas/microbiología , Infecciones Neumocócicas/microbiología , Sistema Respiratorio/microbiología , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/patogenicidad , Animales , Antibacterianos/uso terapéutico , Humanos , Ratones , Enfermedades Nasofaríngeas/tratamiento farmacológico , Infecciones Neumocócicas/tratamiento farmacológico
13.
PLoS Pathog ; 12(3): e1005500, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26975045

RESUMEN

Bacterial uptake by phagocytic cells is a vital event in the clearance of invading pathogens such as Streptococcus pneumoniae. A major role of the P-selectin glycoprotein ligand-1 (PSGL-1) on leukocytes against invasive pneumococcal disease is described in this study. Phagocytosis experiments using different serotypes demonstrated that PSGL-1 is involved in the recognition, uptake and killing of S. pneumoniae. Co-localization of several clinical isolates of S. pneumoniae with PSGL-1 was demonstrated, observing a rapid and active phagocytosis in the presence of PSGL-1. Furthermore, the pneumococcal capsular polysaccharide and the main autolysin of the bacterium--the amidase LytA--were identified as bacterial ligands for PSGL-1. Experimental models of pneumococcal disease including invasive pneumonia and systemic infection showed that bacterial levels were markedly increased in the blood of PSGL-1-/- mice. During pneumonia, PSGL-1 controls the severity of pneumococcal dissemination from the lung to the bloodstream. In systemic infection, a major role of PSGL-1 in host defense is to clear the bacteria in the systemic circulation controlling bacterial replication. These results confirmed the importance of this receptor in the recognition and clearance of S. pneumoniae during invasive pneumococcal disease. Histological and cellular analysis demonstrated that PSGL-1-/- mice have increased levels of T cells migrating to the lung than the corresponding wild-type mice. In contrast, during systemic infection, PSGL-1-/- mice had increased numbers of neutrophils and macrophages in blood, but were less effective controlling the infection process due to the lack of this functional receptor. Overall, this study demonstrates that PSGL-1 is a novel receptor for S. pneumoniae that contributes to protection against invasive pneumococcal disease.


Asunto(s)
Leucocitos/inmunología , Glicoproteínas de Membrana/inmunología , Infecciones Neumocócicas/inmunología , Neumonía Neumocócica/inmunología , Streptococcus pneumoniae/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Pulmón/inmunología , Macrófagos/patología , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Neutrófilos/inmunología , Fagocitosis/inmunología , Sepsis/microbiología
14.
J Virol ; 90(24): 11220-11230, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27707923

RESUMEN

Most double-stranded RNA (dsRNA) viruses are transcribed and replicated in a specialized icosahedral capsid with a T=1 lattice consisting of 60 asymmetric capsid protein (CP) dimers. These capsids help to organize the viral genome and replicative complex(es). They also act as molecular sieves that isolate the virus genome from host defense mechanisms and allow the passage of nucleotides and viral transcripts. Rosellinia necatrix quadrivirus 1 (RnQV1), the type species of the family Quadriviridae, is a dsRNA fungal virus with a multipartite genome consisting of four monocistronic segments (segments 1 to 4). dsRNA-2 and dsRNA-4 encode two CPs (P2 and P4, respectively), which coassemble into ∼450-Å-diameter capsids. We used three-dimensional cryo-electron microscopy combined with complementary biophysical techniques to determine the structures of RnQV1 virion strains W1075 and W1118. RnQV1 has a quadripartite genome, and the capsid is based on a single-shelled T=1 lattice built of P2-P4 dimers. Whereas the RnQV1-W1118 capsid is built of full-length CP, P2 and P4 of RnQV1-W1075 are cleaved into several polypeptides, maintaining the capsid structural organization. RnQV1 heterodimers have a quaternary organization similar to that of homodimers of reoviruses and other dsRNA mycoviruses. The RnQV1 capsid is the first T=1 capsid with a heterodimer as an asymmetric unit reported to date and follows the architectural principle for dsRNA viruses that a 120-subunit capsid is a conserved assembly that supports dsRNA replication and organization. IMPORTANCE: Given their importance to health, members of the family Reoviridae are the basis of most structural and functional studies and provide much of our knowledge of dsRNA viruses. Analysis of bacterial, protozoal, and fungal dsRNA viruses has improved our understanding of their structure, function, and evolution, as well. Here, we studied a dsRNA virus that infects the fungus Rosellinia necatrix, an ascomycete that is pathogenic to a wide range of plants. Using three-dimensional cryo-electron microscopy and analytical ultracentrifugation analysis, we determined the structure and stoichiometry of Rosellinia necatrix quadrivirus 1 (RnQV1). The RnQV1 capsid is a T=1 capsid with 60 heterodimers as the asymmetric units. The large amount of genetic information used by RnQV1 to construct a simple T=1 capsid is probably related to the numerous virus-host and virus-virus interactions that it must face in its life cycle, which lacks an extracellular phase.


Asunto(s)
Proteínas de la Cápside/química , Cápside/ultraestructura , Genoma Viral , Virus ARN/ultraestructura , ARN Viral/ultraestructura , Virión/ultraestructura , Secuencia de Aminoácidos , Cápside/química , Proteínas de la Cápside/ultraestructura , Microscopía por Crioelectrón , Multimerización de Proteína , Estructura Secundaria de Proteína , Virus ARN/química , ARN Viral/metabolismo , Virión/química , Replicación Viral
15.
PLoS Pathog ; 10(5): e1004157, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24873828

RESUMEN

The infectivity of rotavirus, the main causative agent of childhood diarrhea, is dependent on activation of the extracellular viral particles by trypsin-like proteases in the host intestinal lumen. This step entails proteolytic cleavage of the VP4 spike protein into its mature products, VP8* and VP5*. Previous cryo-electron microscopy (cryo-EM) analysis of trypsin-activated particles showed well-resolved spikes, although no density was identified for the spikes in uncleaved particles; these data suggested that trypsin activation triggers important conformational changes that give rise to the rigid, entry-competent spike. The nature of these structural changes is not well understood, due to lack of data relative to the uncleaved spike structure. Here we used cryo-EM and cryo-electron tomography (cryo-ET) to characterize the structure of the uncleaved virion in two model rotavirus strains. Cryo-EM three-dimensional reconstruction of uncleaved virions showed spikes with a structure compatible with the atomic model of the cleaved spike, and indistinguishable from that of digested particles. Cryo-ET and subvolume average, combined with classification methods, resolved the presence of non-icosahedral structures, providing a model for the complete structure of the uncleaved spike. Despite the similar rigid structure observed for uncleaved and cleaved particles, trypsin activation is necessary for successful infection. These observations suggest that the spike precursor protein must be proteolytically processed, not to achieve a rigid conformation, but to allow the conformational changes that drive virus entry.


Asunto(s)
Rotavirus/metabolismo , Virión/aislamiento & purificación , Internalización del Virus , Animales , Cápside/metabolismo , Células Cultivadas , Diarrea/microbiología , Haplorrinos , Tripsina/metabolismo , Acoplamiento Viral
16.
Infect Immun ; 83(2): 591-603, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25404032

RESUMEN

The complement system is a key component of the host immune response for the recognition and clearance of Streptococcus pneumoniae. In this study, we demonstrate that the amidase LytA, the main pneumococcal autolysin, inhibits complement-mediated immunity independently of effects on pneumolysin by a complex process of impaired complement activation, increased binding of complement regulators, and direct degradation of complement C3. The use of human sera depleted of either C1q or factor B confirmed that LytA prevented activation of both the classical and alternative pathways, whereas pneumolysin inhibited only the classical pathway. LytA prevented binding of C1q and the acute-phase protein C-reactive protein to S. pneumoniae, thereby reducing activation of the classical pathway on the bacterial surface. In addition, LytA increased recruitment of the complement downregulators C4BP and factor H to the pneumococcal cell wall and directly cleaved C3b and iC3b to generate degradation products. As a consequence, C3b deposition and phagocytosis increased in the absence of LytA and were markedly enhanced for the lytA ply double mutant, confirming that a combination of LytA and Ply is essential for the establishment of pneumococcal pneumonia and sepsis in a murine model of infection. These data demonstrate that LytA has pleiotropic effects on complement activation, a finding which, in combination with the effects of pneumolysin on complement to assist with pneumococcal complement evasion, confirms a major role of both proteins for the full virulence of the microorganism during septicemia.


Asunto(s)
Pared Celular/inmunología , Activación de Complemento/inmunología , Complemento C3/metabolismo , Interacciones Huésped-Patógeno/inmunología , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Infecciones Neumocócicas/inmunología , Streptococcus pneumoniae/inmunología , Animales , Cápsulas Bacterianas/inmunología , Proteínas Bacterianas/genética , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Pared Celular/enzimología , Complemento C3/antagonistas & inhibidores , Complemento C3/inmunología , Factor H de Complemento/inmunología , Antígenos de Histocompatibilidad/inmunología , Ratones , Ratones Endogámicos C57BL , N-Acetil Muramoil-L-Alanina Amidasa/genética , Fagocitosis/inmunología , Fosforilcolina/metabolismo , Infecciones Neumocócicas/microbiología , Polisacáridos Bacterianos/inmunología , Sepsis/inmunología , Sepsis/microbiología , Estreptolisinas/genética , Estreptolisinas/inmunología
17.
Ginecol Obstet Mex ; 82(10): 672-87, 2014 Oct.
Artículo en Español | MEDLINE | ID: mdl-25510059

RESUMEN

BACKGROUND: In major regions of the world, the importance of gynecological care to children and adolescents has been recognized. There are multiple publications, journals and associations dedicated to this purpose. In Mexico, it has not been the case. OBJECTIVE: The aim of this publication is to raise awareness to the medical community about the importance of sub specialized gynecological care to children and adolescents. MATERIAL AND METHODS: Retrospective study. The number of office evalu- ations issued by the Department of Gynecology of the National Institute of Pediatrics (INP) from January 1, 2002 to December 31, 2013 were counted. Results were grouped by age groups. Group 1: 1 year or less. Group 2: 2 to 9 years. Group 3: 10 to 18 years. The major causes of morbidity were analyzed by groups and in general. RESULTS: In the 12 year period reported, 21,190 girls granted gynecological consultation: 15.2% were first consultations (n = 3,221), 74.76% subsequent consultations (n = 15,842) and 10.04% evaluations and interconsultations (n = 2,127). The yearly average was 1,766 consultations. From 2002 to 2005, two certififyed obstetrician-gynecologists (OB-GYN) worked in the Departament, with the subsecuent increase in the number of attentions; 2005 was the year with the highest productivity (2,265). From 2006, only one OB-GYN continued laboring, and the number of visits decreased gradually. 2013 was the year with fewer productivity (1,351). The main causes of morbidity were: abnormal uterine bleeding (26.48%), inflammatory conditions of vagina and vulva (13.58%), dysmenorrhea (12.31%); which occupied 52.37% of the total (10,404 / 19,867). 81% of the patients corresponded to group 3 (17,079/21,190). To a younger patient, corresponded a smaller number of visits. CONCLUSION: It is required to institute the subspecialty of Child and Adolescent Gynecology in Mexico and to establish Services formed by subspecialists in this matter in the top pediatric hospitals of the country.


Asunto(s)
Servicios de Salud del Adolescente , Servicios de Salud del Niño , Enfermedades de los Genitales Femeninos , Ginecología , Pediatría , Academias e Institutos , Adolescente , Niño , Femenino , Enfermedades de los Genitales Femeninos/diagnóstico , Enfermedades de los Genitales Femeninos/terapia , Humanos , México , Estudios Retrospectivos , Factores de Tiempo
18.
Respir Med Case Rep ; 49: 102027, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38737834

RESUMEN

Pneumatoceles are thin-walled, air or fluid-filled cysts within the lung parenchyma typically formed due to inflammation or bronchial injury from infectious and non-infectious etiologies. To our knowledge, there are only a handful of cases in the literature reporting complicated pneumatoceles as a result of acute respiratory distress without the use of positive-pressure ventilation. We present a unique case of a 34-year-old male who rapidly developed complicated pneumatoceles associated with SARS-CoV-2 pneumonia, without positive pressure ventilation, with complete resolution after conservative management.

19.
J Infect Public Health ; 17(6): 1047-1049, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38678725

RESUMEN

Legionellers' desease accounts for 1-8 % of cases of severe community-acquired pneumonia (CAP). Legionella spp. Is the causative organism that can result in respiratory failure, multi-organ dysfunction, sepsis, and death. Therefore, rapid diagnosis and efficient treatment are crucial. We report the clinical and microbiology study of a patient with community-acquired pneumonia caused by Legionella pneumophila, with fatal outcome. After death, the strain causing the infection was identified as Legionella pneumophila serogroup 1, Olda OLDA phenotype and sequence-type 1. This is the first reported case of septic shock and death associated with an isolate of these characteristics.


Asunto(s)
Infecciones Comunitarias Adquiridas , Legionella pneumophila , Enfermedad de los Legionarios , Choque Séptico , Humanos , Infecciones Comunitarias Adquiridas/microbiología , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Infecciones Comunitarias Adquiridas/diagnóstico , Legionella pneumophila/aislamiento & purificación , Legionella pneumophila/genética , Choque Séptico/microbiología , Enfermedad de los Legionarios/diagnóstico , Enfermedad de los Legionarios/microbiología , Resultado Fatal , Masculino , Anciano , Serogrupo , Persona de Mediana Edad
20.
J Glob Antimicrob Resist ; 37: 75-80, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38452900

RESUMEN

OBJECTIVES: P. aeruginosa is one of the most metabolically versatile bacteria having the ability to survive in multiple environments through its accessory genome. An important hallmark of P. aeruginosa is the high level of antibiotic resistance, which often makes eradication difficult and sometimes impossible. Evolutionary forces have led to this bacterium to develop high antimicrobial resistance with a variety of elements contributing to both intrinsic and acquired resistance. The objectives were to genetically and phenotypically characterizer P. aeruginosa strains isolated from companion animals of different species. METHODS: We characterized a collection of 39 P. aeruginosa strains isolated from infected animals. The genetic characterization was in relation to chromosomal profile by PFGE; content of virulence gene; presence of genomic islands (GIs); genes of the cytotoxins exported by T3SS: exoU, exoS, exoT and exoY; and type IV pili allele. The phenotypic characterization was based on patterns of susceptibility to different antimicrobials. RESULTS: Each strain had a PFGE profile, a high virulence genes content, and a large accessory genome. However, most of the strains presented high sensitivity to almost all antimicrobials tested, showing no acquired resistance (no ß-lactamases). The exception to this lack of resistance was seen with penicillin. CONCLUSIONS: P. aeruginosa could be a naturally sensitive bacterium to standard antimicrobials but could rapidly develop intrinsic and acquired resistance when the bacterium is exposed to pressure exerted by antibiotics, as observed in hospital settings.


Asunto(s)
Antibacterianos , Islas Genómicas , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Factores de Virulencia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Pseudomonas aeruginosa/aislamiento & purificación , Animales , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/veterinaria , Antibacterianos/farmacología , Factores de Virulencia/genética , Virulencia/genética , Farmacorresistencia Bacteriana Múltiple/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA