Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Cell ; 174(5): 1293-1308.e36, 2018 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-29961579

RESUMEN

Knowledge of immune cell phenotypes in the tumor microenvironment is essential for understanding mechanisms of cancer progression and immunotherapy response. We profiled 45,000 immune cells from eight breast carcinomas, as well as matched normal breast tissue, blood, and lymph nodes, using single-cell RNA-seq. We developed a preprocessing pipeline, SEQC, and a Bayesian clustering and normalization method, Biscuit, to address computational challenges inherent to single-cell data. Despite significant similarity between normal and tumor tissue-resident immune cells, we observed continuous phenotypic expansions specific to the tumor microenvironment. Analysis of paired single-cell RNA and T cell receptor (TCR) sequencing data from 27,000 additional T cells revealed the combinatorial impact of TCR utilization on phenotypic diversity. Our results support a model of continuous activation in T cells and do not comport with the macrophage polarization model in cancer. Our results have important implications for characterizing tumor-infiltrating immune cells.


Asunto(s)
Neoplasias de la Mama/inmunología , Regulación Neoplásica de la Expresión Génica , Receptores de Antígenos de Linfocitos T/metabolismo , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Microambiente Tumoral/inmunología , Teorema de Bayes , Neoplasias de la Mama/patología , Análisis por Conglomerados , Biología Computacional , Femenino , Perfilación de la Expresión Génica , Humanos , Sistema Inmunológico , Inmunoterapia/métodos , Ganglios Linfáticos , Linfocitos Infiltrantes de Tumor , Macrófagos/metabolismo , Fenotipo , Transcriptoma
2.
Immunity ; 50(5): 1202-1217.e7, 2019 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-31027997

RESUMEN

Stable changes in chromatin states and gene expression in cells of the immune system form the basis for memory of infections and other challenges. Here, we used naturally occurring cis-regulatory variation in wild-derived inbred mouse strains to explore the mechanisms underlying long-lasting versus transient gene regulation in CD8 T cells responding to acute viral infection. Stably responsive DNA elements were characterized by dramatic and congruent chromatin remodeling events affecting multiple neighboring sites and required distinct transcription factor (TF) binding motifs for their accessibility. Specifically, we found that cooperative recruitment of T-box and Runx family transcription factors to shared targets mediated stable chromatin remodeling upon T cell activation. Our observations provide insights into the molecular mechanisms driving virus-specific CD8 T cell responses and suggest a general mechanism for the formation of transcriptional and epigenetic memory applicable to other immune and non-immune cells.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Ensamble y Desensamble de Cromatina/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Regulación de la Expresión Génica/genética , Coriomeningitis Linfocítica/inmunología , Virus de la Coriomeningitis Linfocítica/inmunología , Proteínas de Dominio T Box/genética , Animales , Linfocitos T CD8-positivos/virología , Línea Celular , Cromatina/genética , Epigénesis Genética/genética , Femenino , Expresión Génica/genética , Regulación de la Expresión Génica/inmunología , Variación Genética , Memoria Inmunológica/genética , Memoria Inmunológica/inmunología , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Coriomeningitis Linfocítica/virología , Masculino , Ratones , Ratones Endogámicos C57BL , Transcripción Genética/genética
3.
Emerg Infect Dis ; 30(11): 2385-2390, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39322418

RESUMEN

We studied a community cluster of 25 mpox cases in Vietnam caused by emerging monkeypox virus sublineage C.1 and imported into Vietnam through 2 independent events; 1 major cluster carried a novel APOBEC3-like mutation. Three patients died; all had advanced HIV co-infection. Viral evolution and its potential consequences should be closely monitored.


Asunto(s)
Monkeypox virus , Mpox , Filogenia , Vietnam/epidemiología , Humanos , Mpox/epidemiología , Mpox/virología , Mpox/transmisión , Monkeypox virus/genética , Monkeypox virus/clasificación , Masculino , Femenino , Adulto , Persona de Mediana Edad , Enfermedades Transmisibles Emergentes/virología , Enfermedades Transmisibles Emergentes/transmisión , Enfermedades Transmisibles Emergentes/epidemiología , Infecciones por VIH/transmisión , Infecciones por VIH/virología , Infecciones por VIH/epidemiología , Historia del Siglo XXI , Mutación , Coinfección/virología
4.
Emerg Infect Dis ; 29(5): 1002-1006, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37015283

RESUMEN

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , SARS-CoV-2/genética , Vietnam/epidemiología , Brotes de Enfermedades
5.
Eur J Haematol ; 111(1): 96-102, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36971022

RESUMEN

OBJECTIVE: To describe the incidence of cardiotoxicity in patients with anthracycline exposure who subsequently receive EPOCH for non-Hodgkin lymphoma (NHL). METHODS: We conducted a retrospective cohort study of adults with anthracycline exposure who subsequently received EPOCH for NHL at Memorial Sloan Kettering Cancer Center. The primary outcome was cumulative incidence of arrhythmia, heart failure (HF), left ventricular (LV) dysfunction, or cardiac death. RESULTS: Among 140 patients, most had diffuse large B-cell lymphoma. Inclusive of EPOCH, median cumulative doxorubicin-equivalent dose was 364 mg/m2 ; exposure was 400 mg/m2 or higher in 41%. With median 36-month follow-up, 23 cardiac events were noted in 20 patients. Cumulative incidence of cardiac events at 60 months was 15% (95% confidence interval [CI]: 9%-21%). When limited to LV dysfunction/HF, cumulative incidence at 60 months was 7% (95% CI: 3%-13%), with most events occurring after the first year. Univariate analysis indicated only history of cardiac disease and dyslipidemia to be associated with cardiotoxicity; no other risk factors, including cumulative anthracycline dose, were identified. CONCLUSIONS: In this retrospective cohort, representing the largest experience in this setting with extended follow-up, cumulative incidence of cardiac events was low. Rates of LV dysfunction or HF were particularly low, suggesting infusional administration may mitigate risk despite prior exposure.


Asunto(s)
Insuficiencia Cardíaca , Linfoma no Hodgkin , Disfunción Ventricular Izquierda , Adulto , Humanos , Estudios Retrospectivos , Incidencia , Cardiotoxicidad/epidemiología , Cardiotoxicidad/etiología , Linfoma no Hodgkin/tratamiento farmacológico , Linfoma no Hodgkin/complicaciones , Insuficiencia Cardíaca/inducido químicamente , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/complicaciones , Antibióticos Antineoplásicos/uso terapéutico , Antraciclinas/efectos adversos , Disfunción Ventricular Izquierda/inducido químicamente , Disfunción Ventricular Izquierda/complicaciones
6.
Int J Health Plann Manage ; 37(1): 5-13, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34490663

RESUMEN

In responding to the COVID-19 pandemic, each country is presented with both opportunities and challenges, some unique and some shared with the global community. It is important to not only recognize, but to embrace them as drivers of the public to the current pandemic success. In this commentary, we discuss the opportunities and challenges that may affect ongoing public health programming in Australia within the current context of epidemiology. COVID-19 within Australia has to date been effectively suppressed through the implementation of nationally coordinated, in which the state delivered public policy, guidelines and practice, and successful establishment of a comprehensive testing, contact tracing, patient isolation and contact quarantine regime combined with national and state social distancing, hygiene etiquette and movement restrictions. However, despite its success to date great challenges lay ahead for future public health policy with the threat of a second wave, or more likely, multiple smaller outbreaks across various population centres. Therefore, policies that aim to balance the twin socioeconomic and health impacts are crucial. The experience of Australia in managing its COVID-19 response can provide a case study for other countries to reshape or adapt their policies and actions in the context of emerging global health crises.


Asunto(s)
COVID-19 , Pandemias , Humanos , Pandemias/prevención & control , Salud Pública , Cuarentena , SARS-CoV-2
7.
J Oncol Pharm Pract ; 27(2): 389-394, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33459159

RESUMEN

PURPOSE: With the rapid spread of COVID-19 in New York City since early March 2020, innovative measures were needed for clinical pharmacy specialists to provide direct clinical care safely to cancer patients. Allocating the workforce was necessary to meet the surging needs of the inpatient services due to the COVID-19 outbreak, which had the potential to compromise outpatient services. We present here our approach of restructuring clinical pharmacy services and providing direct patient care in outpatient clinics during the pandemic. DATA SOURCES: We conducted a retrospective review of electronic clinical documentation involving clinical pharmacy specialist patient encounters in 9 outpatient clinics from March 1, 2020 to May 31, 2020. The analysis of the clinical pharmacy specialist interventions and the impact of the interventions was descriptive. DATA SUMMARY: As hospital services were modified to handle the surge due to COVID-19, select clinical pharmacy specialists were redeployed from the outpatient clinics or research blocks to COVID-19 inpatient teams. During these 3 months, clinical pharmacy specialists were involved in 2535 patient visits from 9 outpatient clinics and contributed a total of 4022 interventions, the majority of which utilized telemedicine. The interventions provided critical clinical pharmacy care during the pandemic and omitted 199 in-person visits for medical care. CONCLUSION: The swift transition to telemedicine allowed the provision of direct clinical pharmacy services to patients with cancer during the COVID-19 pandemic.


Asunto(s)
Instituciones de Atención Ambulatoria/organización & administración , COVID-19 , Instituciones Oncológicas/organización & administración , Neoplasias/terapia , Pandemias , Servicio de Farmacia en Hospital/organización & administración , COVID-19/terapia , Humanos , Ciudad de Nueva York , Atención al Paciente , Farmacéuticos , Rol Profesional , Estudios Retrospectivos , Telemedicina
8.
Genome Res ; 27(9): 1573-1588, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28768687

RESUMEN

Prioritizing molecular alterations that act as drivers of cancer remains a crucial bottleneck in therapeutic development. Here we introduce HIT'nDRIVE, a computational method that integrates genomic and transcriptomic data to identify a set of patient-specific, sequence-altered genes, with sufficient collective influence over dysregulated transcripts. HIT'nDRIVE aims to solve the "random walk facility location" (RWFL) problem in a gene (or protein) interaction network, which differs from the standard facility location problem by its use of an alternative distance measure: "multihitting time," the expected length of the shortest random walk from any one of the set of sequence-altered genes to an expression-altered target gene. When applied to 2200 tumors from four major cancer types, HIT'nDRIVE revealed many potentially clinically actionable driver genes. We also demonstrated that it is possible to perform accurate phenotype prediction for tumor samples by only using HIT'nDRIVE-seeded driver gene modules from gene interaction networks. In addition, we identified a number of breast cancer subtype-specific driver modules that are associated with patients' survival outcome. Furthermore, HIT'nDRIVE, when applied to a large panel of pan-cancer cell lines, accurately predicted drug efficacy using the driver genes and their seeded gene modules. Overall, HIT'nDRIVE may help clinicians contextualize massive multiomics data in therapeutic decision making, enabling widespread implementation of precision oncology.


Asunto(s)
Neoplasias de la Mama/genética , Variaciones en el Número de Copia de ADN/genética , Programas Informáticos , Transcriptoma/genética , Neoplasias de la Mama/patología , Biología Computacional , Femenino , Genómica , Humanos , Mutación , Mapas de Interacción de Proteínas/genética
9.
BMC Med Genet ; 20(1): 115, 2019 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-31248375

RESUMEN

BACKGROUND: Calreticulin (CALR) gene mutations are currently recommended as biomarkers in diagnosis of patients with myeloproliferative neoplasms (MPN) with Jak2 V617F negative phenotype. Our aim was to establish a rapid, low cost and sensitive assay for identification of CALR gene mutations and to validate the diagnostic performance of the established assay in a patient cohort with different clinical MPN phenotypes. METHODS: One hundred five Philadelphia-negative MPN patients, including polycythemia vera (PV), essential thrombocythaemia (ET), and primary myelofibrosis (PMF) were initially screened for JAK2 mutations by amplification-refractory mutation system (ARMS-PCR) methodology and were further subjected to detection of CALR gene mutations by our in-house assay, a PCR based amplicon length differentiation assay (PCR-ALDA). The PCR-ALDA methodology was compared with real time PCR and Sanger sequencing methods. Furthermore, the analytical sensitivity of the assay was established. RESULTS: PCR - ALDA approach was able to detect and discriminate the pseudo-positive samples containing more than 1% CALR mutant alleles. CALR mutations were not detected in 63 Jak2 V617F positive cases in all three methods. In contrast, amongst 42 Jak2 V617F negative cases, both PCR-ALDA and Sanger sequencing coherently identified 12 CALR mutants compared to 10 CALR mutants detected by real-time PCR method. CONCLUSION: PCR-ALDA can be utilized as an easy-to-use, rapid, low cost and sensitive tool in the detection of CALR mutations in Philadelphia-negative MPN patients.


Asunto(s)
Calreticulina/genética , Mutación , Trastornos Mieloproliferativos/diagnóstico , Trastornos Mieloproliferativos/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Biomarcadores de Tumor , Análisis Costo-Beneficio , Femenino , Técnicas de Genotipaje/métodos , Humanos , Janus Quinasa 2/genética , Leucemia Mieloide Crónica Atípica BCR-ABL Negativa , Masculino , Persona de Mediana Edad , Fenotipo , Policitemia Vera , Mielofibrosis Primaria , Reacción en Cadena en Tiempo Real de la Polimerasa/economía , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Sensibilidad y Especificidad , Trombocitemia Esencial , Adulto Joven
10.
BMC Med Genet ; 20(1): 201, 2019 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-31864292

RESUMEN

BACKGROUND: Vitamin D derivatives and their receptor (VDR) are potent modulators of immune responses in various diseases including malignancies as well as in metabolic and infectious disorders. The impact of vitamin D receptor polymorphisms on clinical outcomes of hepatitis B virus (HBV) infection is not well understood. This study aims to investigate the potential role of VDR polymorphisms (TaqI, FokI, ApaI, and BsmI) in Vietnamese HBV infected patients and to correlate these polymorphisms with the progression of HBV-related liver disease. METHODS: Four hundred forty-three HBV infected patients of the three clinically well-defined subgroups chronic hepatitis B (CHB, n = 183), liver cirrhosis (LC, n = 89) and hepatocellular carcinoma (HCC, n = 171) and 238 healthy individuals (HC) were enrolled. VDR polymorphisms were genotyped by DNA sequencing and in-house validated ARMS assays. Logistic regression models were applied in order to determine the association of VDR polymorphisms with manifest HBV infection as well as with progression of related liver diseases mulin different genetic models. RESULTS: The VDR ApaI CA genotype was less frequent in HCC than in CHB patients in different genetic models (codominant model, OR = 0.5, 95%CI = 0.3-0.84, P = 0.004; dominant model, OR = 0.46, 95%CI = 0.27-0.76, P = 0.0023). In the recessive model, the genotype ApaI AA was found more frequently among HCC compared to CHB patients (OR = 2.56, 95%CI = 1.01-6.48, P = 0.04). Similarly, the ApaI CA genotype was less frequent in HCC than in non-HCC group codominant model, OR = 0.6, 95%CI = 0.4-0.98, dominant model, P = 0.04 and OR = 0.6, 95%CI = 0.38-0.90, P = 0.017). The ApaI genotypes CA and AA was significantly associated with higher levels of liver enzymes, bilirubin, and HBV DNA (P < 0.05). No association between TaqI, FokI and BsmI polymorphisms and any clinical outcome as well as liver disease progression was found. CONCLUSIONS: Among the four investigated VDR polymorphisms, ApaI is associated with clinical outcome and liver disease progression in Vietnamese HBV infected patients.


Asunto(s)
Carcinoma Hepatocelular/genética , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Virus de la Hepatitis B/aislamiento & purificación , Neoplasias Hepáticas/genética , Polimorfismo de Nucleótido Simple , Receptores de Calcitriol/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/virología , Estudios de Casos y Controles , Progresión de la Enfermedad , Genotipo , Humanos , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/virología , Vietnam
12.
BMC Endocr Disord ; 19(1): 121, 2019 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-31711488

RESUMEN

BACKGROUND: Diabetic ketoacidosis (DKA) is an acute, major, life-threatening complication of diabetes that requires immediate treatment. Allergic reaction to insulin is rare, especially when using recombinant human insulin. The clinical presentation of insulin allergy can range from minor local symptoms to a severe generalized allergic reaction such as anaphylaxis. A limited number of cases have been reported on the treatment of severe DKA in patients with type 2 diabetes with insulin allergy. Here, we describe a patient with type 2 diabetes with insulin allergy in which severe DKA resolved after the initiation of continuous intravenous (IV) recombinant human insulin infusion. CASE PRESENTATION: A 58-year-old man with type 2 diabetes initiated subcutaneous insulin administration (SIA) after failure of oral antidiabetic treatment. Symptoms of an allergic reaction developed, including pruritic wheals appearing within 10 min of injection and lasting over 24 h. Both skin prick and intradermal tests were positive with different types of insulin. Two days before admission, he stopped SIA because of allergic symptoms and then experienced weakness and upper abdominal pain. On admission, he was in severe metabolic acidosis with a pH of 6.984 and bicarbonate of 2.5 mmol/litre. The blood glucose level was 20.79 mmol/litre, BUN 4.01 mmol/litre, creatinine 128 µmol/litre, and urinary ketone 11.44 mmol/litre. Over 24 h, metabolic acidosis was refractory to IV fluids, bicarbonate and potassium replacement, as well as haemodialysis. Ultimately, he received continuous IV recombinant human insulin infusion at a rate of 0.1 units/kg/hour, in combination with haemodiafiltration, and no further allergic reactions were observed. On day 5, ketonaemia and metabolic acidosis completely resolved. He had transitioned from IV insulin infusion to SIA on day 14. He was discharged on day 21 with SIA treatment. Three months later, he had good glycaemic control but still had allergic symptoms at the insulin injection sites. CONCLUSIONS: In this patient, SIA caused an allergic reaction, in contrast to continuous IV insulin infusion for which allergic symptoms did not appear. Continuous IV recombinant human insulin infusion in combination with haemodiafiltration could be an option for the treatment of severe DKA in patients with diabetes with insulin allergy.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Cetoacidosis Diabética/tratamiento farmacológico , Hipersensibilidad a las Drogas/prevención & control , Infusiones Intravenosas/métodos , Insulina/administración & dosificación , Cetoacidosis Diabética/etiología , Hipersensibilidad a las Drogas/etiología , Humanos , Insulina/efectos adversos , Sistemas de Infusión de Insulina , Masculino , Persona de Mediana Edad , Pronóstico
13.
PLoS Comput Biol ; 13(10): e1005695, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29023534

RESUMEN

The analysis of the mutational landscape of cancer, including mutual exclusivity and co-occurrence of mutations, has been instrumental in studying the disease. We hypothesized that exploring the interplay between co-occurrence, mutual exclusivity, and functional interactions between genes will further improve our understanding of the disease and help to uncover new relations between cancer driving genes and pathways. To this end, we designed a general framework, BeWith, for identifying modules with different combinations of mutation and interaction patterns. We focused on three different settings of the BeWith schema: (i) BeME-WithFun, in which the relations between modules are enriched with mutual exclusivity, while genes within each module are functionally related; (ii) BeME-WithCo, which combines mutual exclusivity between modules with co-occurrence within modules; and (iii) BeCo-WithMEFun, which ensures co-occurrence between modules, while the within module relations combine mutual exclusivity and functional interactions. We formulated the BeWith framework using Integer Linear Programming (ILP), enabling us to find optimally scoring sets of modules. Our results demonstrate the utility of BeWith in providing novel information about mutational patterns, driver genes, and pathways. In particular, BeME-WithFun helped identify functionally coherent modules that might be relevant for cancer progression. In addition to finding previously well-known drivers, the identified modules pointed to other novel findings such as the interaction between NCOR2 and NCOA3 in breast cancer. Additionally, an application of the BeME-WithCo setting revealed that gene groups differ with respect to their vulnerability to different mutagenic processes, and helped us to uncover pairs of genes with potentially synergistic effects, including a potential synergy between mutations in TP53 and the metastasis related DCC gene. Overall, BeWith not only helped us uncover relations between potential driver genes and pathways, but also provided additional insights on patterns of the mutational landscape, going beyond cancer driving mutations. Implementation is available at https://www.ncbi.nlm.nih.gov/CBBresearch/Przytycka/software/bewith.html.


Asunto(s)
Biología Computacional/métodos , Redes Reguladoras de Genes/genética , Neoplasias/genética , Neoplasias/metabolismo , Algoritmos , Humanos , Péptidos y Proteínas de Señalización Intracelular/análisis , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Mutación/genética
14.
PLoS Comput Biol ; 12(4): e1004821, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27078128

RESUMEN

Recent genome-wide analyses have uncovered a high accumulation of RNA polymerase II (Pol II) at the 5' end of genes. This elevated Pol II presence at promoters, referred to here as Poll II poising, is mainly (but not exclusively) attributed to temporal pausing of transcription during early elongation which, in turn, has been proposed to be a regulatory step for processes that need to be activated "on demand". Yet, the full genome-wide regulatory role of Pol II poising is yet to be delineated. To elucidate the role of Pol II poising in B cell activation, we compared Pol II profiles in resting and activated B cells. We found that while Pol II poised genes generally overlap functionally among different B cell states and correspond to the functional groups previously identified for other cell types, non-poised genes are B cell state specific. Focusing on the changes in transcription activity upon B cell activation, we found that the majority of such changes were from poised to non-poised state. The genes showing this type of transition were functionally enriched in translation, RNA processing and mRNA metabolic process. Interestingly, we also observed a transition from non-poised to poised state. Within this set of genes we identified several Immediate Early Genes (IEG), which were highly expressed in resting B cell and shifted from non-poised to poised state after B cell activation. Thus Pol II poising does not only mark genes for rapid expression in the future, but it is also associated with genes that are silenced after a burst of their expression. Finally, we performed comparative analysis of the presence of G4 motifs in the context of poised versus non-poised but active genes. Interestingly we observed a differential enrichment of these motifs upstream versus downstream of TSS depending on poising status. The enrichment of G4 sequence motifs upstream of TSS of non-poised active genes suggests a potential role of quadruplexes in expression regulation.


Asunto(s)
Linfocitos B/enzimología , ARN Polimerasa II/metabolismo , Animales , Linfocitos B/citología , Linfocitos B/inmunología , Biología Computacional , G-Cuádruplex , Regulación de la Expresión Génica , Genes Inmediatos-Precoces , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Regiones Promotoras Genéticas , Elongación de la Transcripción Genética , Sitio de Iniciación de la Transcripción
15.
Nucleic Acids Res ; 43(12): 5699-707, 2015 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-25870409

RESUMEN

High-Throughput (HT) SELEX combines SELEX (Systematic Evolution of Ligands by EXponential Enrichment), a method for aptamer discovery, with massively parallel sequencing technologies. This emerging technology provides data for a global analysis of the selection process and for simultaneous discovery of a large number of candidates but currently lacks dedicated computational approaches for their analysis. To close this gap, we developed novel in-silico methods to analyze HT-SELEX data and utilized them to study the emergence of polymerase errors during HT-SELEX. Rather than considering these errors as a nuisance, we demonstrated their utility for guiding aptamer discovery. Our approach builds on two main advancements in aptamer analysis: AptaMut-a novel technique allowing for the identification of polymerase errors conferring an improved binding affinity relative to the 'parent' sequence and AptaCluster-an aptamer clustering algorithm which is to our best knowledge, the only currently available tool capable of efficiently clustering entire aptamer pools. We applied these methods to an HT-SELEX experiment developing aptamers against Interleukin 10 receptor alpha chain (IL-10RA) and experimentally confirmed our predictions thus validating our computational methods.


Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento , Mutación , Técnica SELEX de Producción de Aptámeros/métodos , Programas Informáticos , Algoritmos , Aptámeros de Nucleótidos/metabolismo , Simulación por Computador , Subunidad alfa del Receptor de Interleucina-10/metabolismo , Modelos Estadísticos , Mutagénesis
16.
J Am Chem Soc ; 138(31): 9747-50, 2016 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-27472048

RESUMEN

We report a (129)Xe NMR relaxation-based sensing approach that exploits changes in the bulk xenon relaxation rate induced by slowed tumbling of a cryptophane-based sensor upon target binding. The amplification afforded by detection of the bulk dissolved xenon allows sensitive detection of targets. The sensor comprises a xenon-binding cryptophane cage, a target interaction element, and a metal chelating agent. Xenon associated with the target-bound cryptophane cage is rapidly relaxed and then detected after exchange with the bulk. Here we show that large macromolecular targets increase the rotational correlation time of xenon, increasing its relaxation rate. Upon binding of a biotin-containing sensor to avidin at 1.5 µM concentration, the free xenon T2 is reduced by a factor of 4.


Asunto(s)
Técnicas Biosensibles , Sustancias Macromoleculares/química , Isótopos de Xenón/química , Biotina/química , Quelantes/química , Espectroscopía de Resonancia Magnética , Metales/química , Peso Molecular , Péptidos/química , Compuestos Policíclicos , Unión Proteica , Solubilidad , Agua/química
17.
Bioinformatics ; 31(12): i284-92, 2015 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-26072494

RESUMEN

MOTIVATION: The data gathered by the Pan-Cancer initiative has created an unprecedented opportunity for illuminating common features across different cancer types. However, separating tissue-specific features from across cancer signatures has proven to be challenging. One of the often-observed properties of the mutational landscape of cancer is the mutual exclusivity of cancer driving mutations. Even though studies based on individual cancer types suggested that mutually exclusive pairs often share the same functional pathway, the relationship between across cancer mutual exclusivity and functional connectivity has not been previously investigated. RESULTS: We introduce a classification of mutual exclusivity into three basic classes: within tissue type exclusivity, across tissue type exclusivity and between tissue type exclusivity. We then combined across-cancer mutual exclusivity with interactions data to uncover pan-cancer dysregulated pathways. Our new method, Mutual Exclusivity Module Cover (MEMCover) not only identified previously known Pan-Cancer dysregulated subnetworks but also novel subnetworks whose across cancer role has not been appreciated well before. In addition, we demonstrate the existence of mutual exclusivity hubs, putatively corresponding to cancer drivers with strong growth advantages. Finally, we show that while mutually exclusive pairs within or across cancer types are predominantly functionally interacting, the pairs in between cancer mutual exclusivity class are more often disconnected in functional networks.


Asunto(s)
Algoritmos , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Mutación , Neoplasias/genética , Humanos , Neoplasias/clasificación
18.
BMC Infect Dis ; 16(1): 507, 2016 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-27659316

RESUMEN

BACKGROUND: As an immune modulator, vitamin D is involved in various pathophysiological mechanisms in a plethora of diseases. This study aims to correlate the vitamin D deficiency status and clinical progression of liver diseases associated with hepatitis B virus (HBV) infection in patients in Vietnam and to compare it to healthy controls. METHODS: We quantified the levels of total vitamin D [25-(OH) D2 and D3] in serum samples from 400 HBV patients (chronic hepatitis B infection [CHB], n = 165; HBV-associated liver cirrhosis [LC], n = 127; HBV-associated hepatocellular carcinoma [HCC], n = 108) and 122 unrelated healthy controls (HC). Univariate and multivariate analyses were performed in order to determine the association between vitamin D levels and distinct clinical parameters. RESULTS: The prevalence of vitamin D inadequacy (<30 ng/mL) was high among healthy individuals (81.7 %) as well as in HBV patients (84.3 %). Vitamin D deficiency (<20 ng/ml) or severe deficiency (<10 ng/ml) was observed more frequently among HBV patients (52 %) and subgroups (CHB, 47.8 %; LC, 54.4 %; HCC, 55.3 %) compared to the control group (32.5 %) (P < 0.001). Vitamin D levels and HBV-DNA load were strongly and inversely correlated (rho = -0.57, P < 0.0001). Multivariate regression analysis also revealed an independent association of HBV-DNA loads with low vitamin D levels (P = 0.0004). In addition, reduced vitamin D levels were associated with significant clinical progression of LC (Child-Pugh C versus Child-Pugh A, P = 0.0018; Child-Pugh C versus Child-Pugh B, P = 0.016). CONCLUSIONS: Vitamin D deficiency was observed in the majority of HBV-infected patients and associated with adverse clinical outcomes. Our findings suggest that substitution of vitamin D may be a supportive option in the treatment of chronic liver diseases, in particular of HBV-associated disorders.

19.
Bioinformatics ; 30(5): 644-51, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-24130305

RESUMEN

MOTIVATION: RNA-Seq technology is promising to uncover many novel alternative splicing events, gene fusions and other variations in RNA transcripts. For an accurate detection and quantification of transcripts, it is important to resolve the mapping ambiguity for those RNA-Seq reads that can be mapped to multiple loci: >17% of the reads from mouse RNA-Seq data and 50% of the reads from some plant RNA-Seq data have multiple mapping loci. In this study, we show how to resolve the mapping ambiguity in the presence of novel transcriptomic events such as exon skipping and novel indels towards accurate downstream analysis. We introduce ORMAN ( O ptimal R esolution of M ultimapping A mbiguity of R N A-Seq Reads), which aims to compute the minimum number of potential transcript products for each gene and to assign each multimapping read to one of these transcripts based on the estimated distribution of the region covering the read. ORMAN achieves this objective through a combinatorial optimization formulation, which is solved through well-known approximation algorithms, integer linear programs and heuristics. RESULTS: On a simulated RNA-Seq dataset including a random subset of transcripts from the UCSC database, the performance of several state-of-the-art methods for identifying and quantifying novel transcripts, such as Cufflinks, IsoLasso and CLIIQ, is significantly improved through the use of ORMAN. Furthermore, in an experiment using real RNA-Seq reads, we show that ORMAN is able to resolve multimapping to produce coverage values that are similar to the original distribution, even in genes with highly non-uniform coverage. AVAILABILITY: ORMAN is available at http://orman.sf.net


Asunto(s)
Perfilación de la Expresión Génica/métodos , Isoformas de ARN/metabolismo , Análisis de Secuencia de ARN/métodos , Programas Informáticos , Algoritmos , Empalme Alternativo , Exones , Humanos , Isoformas de ARN/química , Alineación de Secuencia
20.
Chemphyschem ; 16(17): 3573-7, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26376768

RESUMEN

Recent work has shown that xenon chemical shifts in cryptophane-cage sensors are affected when tethered chelators bind to metals. Here, we explore the xenon shifts in response to a wide range of metal ions binding to diastereomeric forms of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) linked to cryptophane-A. The shifts induced by the binding of Ca(2+) , Cu(2+) , Ce(3+) , Zn(2+) , Cd(2+) , Ni(2+) , Co(2+) , Cr(2+) , Fe(3+) , and Hg(2+) are distinct. In addition, the different responses of the diastereomers for the same metal ion indicate that shifts are affected by partial folding with a correlation between the expected coordination number of the metal in the DOTA complex and the chemical shift of (129) Xe. These sensors may be used to detect and quantify many important metal ions, and a better understanding of the basis for the induced shifts could enhance future designs.


Asunto(s)
Quelantes/química , Compuestos Heterocíclicos con 1 Anillo/química , Metales Alcalinotérreos/química , Metales Pesados/química , Cristalografía por Rayos X , Modelos Moleculares , Estructura Molecular , Isótopos de Xenón/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA