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1.
Pilot Feasibility Stud ; 8(1): 264, 2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36564795

RESUMEN

BACKGROUND: Antiretroviral treatment (ART) is the most effective clinical intervention for reducing morbidity and mortality among persons living with HIV. However, in Uganda, there are disparities between men and women in viral load suppression and related HIV care engagement outcomes, which suggests problems with the implementation of ART. Gender norms are a known driver of HIV disparities in sub-Saharan Africa, and patient-provider relationships are a key factor in HIV care engagement; therefore, the role of gender norms is important to consider in interventions to achieve the equitable provision of treatment and the quality of ART counseling. METHODS: The overall research objective of this study is to pilot test an implementation strategy (i.e., methods to improve the implementation of an evidence-based intervention) to increase providers' capacity to provide gender-responsive treatment and counseling to men and women on HIV treatment in Uganda. Delivered to HIV providers, this group training adapts evidence-based strategies to reduce gender biases and increase skills to deliver gender-specific and transformative HIV counseling to patients. The implementation strategy will be piloted through a quasi-experimental controlled trial. Clinics will be randomly assigned to either the intervention or control conditions. The trial will assess feasibility and acceptability and explore barriers and facilitators to implementation and future adoption while gathering preliminary evidence on the implementation strategy's effectiveness by comparing changes in patient (N = 240) and provider (N = 80-140) outcomes across intervention and control clinics through 12-month follow-up. Quantitative data will be descriptively analyzed, qualitative data will be analyzed through thematic analysis, and these data will be mixed during the presentation and interpretation of results where appropriate. DISCUSSION: This pilot intervention trial will gather preliminary evidence on the acceptability, feasibility, and potential effect of a novel implementation strategy to improve men and women's HIV care engagement, with the potential to reduce gender disparities in HIV outcomes. TRIAL REGISTRATION: Clinicaltrials.gov NCT05178979 , retrospectively registered on January 5, 2022.

2.
Int J Tuberc Lung Dis ; 26(8): 720-726, 2022 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-35898127

RESUMEN

BACKGROUND: South Texas has higher TB disease incidence than much of the United States. We evaluated a multi-site South Texas interferon-gamma release assay (IGRA)-based testing and latent TB infection (LTBI) treatment program targeting high-risk populations.METHODS: Number of IGRA tests, test results, LTBI confirmation, and treatment outcomes were collected over 2.5 years. Sixteen semi-structured patient interviews and 10 site-based focus groups were conducted with providers, nurses, and administrators. Grounded theory identified themes associated with successful outcomes.RESULTS: Of 9,050 IGRA tests, 687 (8%) were positive; 340 (49%) confirmed as LTBI; 191 initiated LTBI treatment; and 130 (68% of initiators) completed treatment. Patient barriers to treatment completion included lack of knowledge, misconceptions, and treatment toxicities. Clinic staff concurred that toxicity was a barrier to treatment and requiring new processes with limited resources were implementation barriers.CONCLUSIONS: Over 9,000 patients were screened with a high prevalence of IGRA positivity, but confirming LTBI, initiating, and completing treatment were challenging. Qualitative evaluation supports low literacy patient education on LTBI and toxicities and expanded support for process implementation and provider training. These findings highlight challenges at all levels of the LTBI care cascade and provide patient, staff, and provider perspectives on implementation of these programs.


Asunto(s)
Tuberculosis Latente , Prueba de Tuberculina , Humanos , Ensayos de Liberación de Interferón gamma/métodos , Tuberculosis Latente/diagnóstico , Tuberculosis Latente/tratamiento farmacológico , Tuberculosis Latente/epidemiología , Tamizaje Masivo/métodos , Prevalencia , Prueba de Tuberculina/métodos
4.
Drug Alcohol Depend ; 212: 108039, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32428789

RESUMEN

BACKGROUND: Evidence in different countries suggest an association between sex work and drug use. In the Dominican Republic an estimated 60,000-100,000 women work in the sex industry. However, little is known about their drug use behaviors. OBJECTIVE: To characterize the burden of drug use and examine correlates of these behaviors among female sex workers in the Dominican Republic. METHODS: Data for this analysis comes from a cross-sectional study among key populations at risk for HIV. A community sample of female sex workers (N = 389) was recruited using passive and active recruitment strategies. Participants completed a behavioral survey between 2015 and 2016. Logistic regression models were constructed to examine predictors of drug use. RESULTS: Protective factors against marijuana and crack or cocaine use included being heterosexual, having a higher level of education, regular employment, and fewer male sexual partners. Increased odds of crack or cocaine use were associated with incarceration, having slept in a place not meant for human habitation in the last six months, and having ever lived in a batey (a community around a sugar mill where workers and their families live). Participants that used marijuana were generally younger, while those that used crack or cocaine were older. CONCLUSIONS: Our findings highlight characteristics of the social and economic environment that require further research to optimize prevention and care strategies for this population. Public health interventions are needed that address drug use, sexual risk-taking, and helping female sex workers and their families achieve a healthy life.


Asunto(s)
Trabajadores Sexuales/psicología , Medio Social , Factores Socioeconómicos , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/psicología , Población Urbana/tendencias , Adolescente , Adulto , Estudios Transversales , República Dominicana/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Trabajo Sexual/psicología , Conducta Sexual/psicología , Trastornos Relacionados con Sustancias/economía , Adulto Joven
5.
Ann Oncol ; 31(5): 599-608, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32178965

RESUMEN

BACKGROUND: Programmed death-ligand 1 (PD-L1) expression is the only FDA-approved biomarker for immune checkpoint inhibitors (ICIs) in patients with lung adenocarcinoma, but sensitivity is modest. Understanding the impact of molecular phenotype, clinical characteristics, and tumor features on PD-L1 expression is largely unknown and may improve prediction of response to ICI. PATIENTS AND METHODS: We evaluated patients with lung adenocarcinoma for whom PD-L1 testing and targeted next-generation sequencing (using MSK-IMPACT) was performed on the same tissue sample. Clinical and molecular features were compared across PD-L1 subgroups to examine how molecular phenotype associated with tumor PD-L1 expression. In patients treated with anti-PD-(L)1 blockade, we assessed how these interactions impacted efficacy. RESULTS: A total of 1586 patients with lung adenocarcinoma had paired PD-L1 testing and targeted next-generation sequencing. PD-L1 negativity was more common in primary compared to metastatic samples (P < 0.001). The distribution of PD-L1 expression (lymph nodes enriched for PD-L1 high; bones predominantly PD-L1 negative) and predictiveness of PD-L1 expression on ICI response varied by organ. Mutations in KRAS, TP53, and MET significantly associated with PD-L1 high expression (each P < 0.001, Q < 0.001) and EGFR and STK11 mutations associated with PD-L1 negativity (P < 0.001, Q = 0.01; P = 0.001, Q < 0.001, respectively). WNT pathway alterations also associated with PD-L1 negativity (P = 0.005). EGFR and STK11 mutants abrogated the predictive value of PD-L1 expression on ICI response. CONCLUSION: PD-L1 expression and association with ICI response vary across tissue sample sites. Specific molecular features are associated with differential expression of PD-L1 and may impact the predictive capacity of PD-L1 for response to ICIs.


Asunto(s)
Antígeno B7-H1 , Neoplasias Pulmonares , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Mutación
6.
Br J Surg ; 107(1): 14-19, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31763684

RESUMEN

A subset of patients with early gastric cancer demonstrate early recurrence and poor survival despite margin-negative resection. This study used an extremes-of-survivorship approach to identify an association between TP53 hotspot mutations co-occurring with loss of heterozygosity and unexpectedly poor survival in early gastric cancer. This distinct genomic profile may be a novel biomarker of poor survival in patients with completely resected early gastric cancer, and warrants large-scale validation. Promising, validation needed.


Asunto(s)
Mutación/genética , Neoplasias Gástricas/cirugía , Proteína p53 Supresora de Tumor/genética , Anciano , Biomarcadores de Tumor/genética , Femenino , Marcadores Genéticos/genética , Genómica , Humanos , Pérdida de Heterocigocidad/genética , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/mortalidad , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidad , Secuenciación Completa del Genoma
7.
Ann Oncol ; 30(8): 1221-1231, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31050713

RESUMEN

It is increasingly common in oncology practice to perform tumour sequencing using large cancer panels. For pathogenic sequence variants in cancer susceptibility genes identified on tumour-only sequencing, it is often unclear whether they are of somatic or constitutional (germline) origin. There is wide-spread disparity regarding both the extent to which systematic 'germline-focussed analysis' is carried out upon tumour sequencing data and for which variants follow-up analysis of a germline sample is carried out. Here we present analyses of paired sequencing data from 17 152 cancer samples, in which 1494 pathogenic sequence variants were identified across 65 cancer susceptibility genes. From these analyses, the European Society of Medical Oncology Precision Medicine Working Group Germline Subgroup has generated (i) recommendations regarding germline-focussed analyses of tumour-only sequencing data, (ii) indications for germline follow-up testing and (iii) guidance on patient information-giving and consent.


Asunto(s)
Biomarcadores de Tumor/genética , Pruebas Genéticas/normas , Neoplasias/diagnóstico , Medicina de Precisión/métodos , Análisis Mutacional de ADN , Unión Europea , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Consentimiento Informado/normas , Oncología Médica/métodos , Oncología Médica/normas , Neoplasias/genética , Guías de Práctica Clínica como Asunto , Medicina de Precisión/normas , Sociedades Médicas/normas
9.
Ann Oncol ; 28(9): 2298-2304, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28911072

RESUMEN

BACKGROUND: Genomic profiling is increasingly incorporated into oncology research and the clinical care of cancer patients. We sought to determine physician perception and use of enterprise-scale clinical sequencing at our center, including whether testing changed management and the reasoning behind this decision-making. PATIENTS AND METHODS: All physicians who consented patients to MSK-IMPACT, a next-generation hybridization capture assay, in tumor types where molecular profiling is not routinely performed were asked to complete a questionnaire for each patient. Physician determination of genomic 'actionability' was compared to an expertly curated knowledgebase of somatic variants. Reported management decisions were compared to chart review. RESULTS: Responses were received from 146 physicians pertaining to 1932 patients diagnosed with 1 of 49 cancer types. Physicians indicated that sequencing altered management in 21% (331/1593) of patients in need of a treatment change. Among those in whom treatment was not altered, physicians indicated the presence of an actionable alteration in 55% (805/1474), however, only 45% (362/805) of these cases had a genomic variant annotated as actionable by expert curators. Further evaluation of these patients revealed that 66% (291/443) had a variant in a gene associated with biologic but not clinical evidence of actionability or a variant of unknown significance in a gene with at least one known actionable alteration. Of the cases annotated as actionable by experts, physicians identified an actionable alteration in 81% (362/445). In total, 13% (245/1932) of patients were enrolled to a genomically matched trial. CONCLUSION: Although physician and expert assessment differed, clinicians demonstrate substantial awareness of the genes associated with potential actionability and report using this knowledge to inform management in one in five patients. CLINICAL TRIAL NUMBER: NCT01775072.


Asunto(s)
Perfilación de la Expresión Génica/estadística & datos numéricos , Estudios de Asociación Genética/estadística & datos numéricos , Secuenciación de Nucleótidos de Alto Rendimiento/estadística & datos numéricos , Neoplasias/genética , Oncólogos , Medicina de Precisión/psicología , Femenino , Humanos , Masculino , Neoplasias/terapia , Hibridación de Ácido Nucleico , Percepción
10.
Ann Oncol ; 28(3): 512-518, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-27993796

RESUMEN

Background: Based upon preclinical synergy in murine models, we carried out a phase I trial to determine the maximum tolerated dose (MTD), toxicities, pharmacokinetics, and biomarkers of response for the combination of BKM120, a PI3K inhibitor, and olaparib, a PARP inhibitor. Patients and methods: Olaparib was administered twice daily (tablet formulation) and BKM120 daily on a 28-day cycle, both orally. A 3 + 3 dose-escalation design was employed with the primary objective of defining the combination MTD, and secondary objectives were to define toxicities, activity, and pharmacokinetic profiles. Eligibility included recurrent breast (BC) or ovarian cancer (OC); dose-expansion cohorts at the MTD were enrolled for each cancer. Results: In total, 69 of 70 patients enrolled received study treatment; one patient never received study treatment because of ineligibility. Twenty-four patients had BC; 46 patients had OC. Thirty-five patients had a germline BRCA mutation (gBRCAm). Two DLTs (grade 3 transaminitis and hyperglycemia) were observed at DL0 (BKM120 60 mg/olaparib and 100 mg b.i.d.). The MTD was determined to be BKM120 50 mg q.d. and olaparib 300 mg b.i.d. (DL8). Additional DLTs included grade 3 depression and transaminitis, occurring early in cycle 2 (DL7). Anticancer activity was observed in BC and OC and in gBRCAm and gBRCA wild-type (gBRCAwt) patients. Conclusions: BKM120 and olaparib can be co-administered, but the combination requires attenuation of the BKM120 dose. Clinical benefit was observed in both gBRCAm and gBRCAwt pts. Randomized phase II studies will be needed to further define the efficacy of PI3K/PARP-inhibitor combinations as compared with a PARP inhibitor alone.


Asunto(s)
Aminopiridinas/administración & dosificación , Proteína BRCA1/genética , Proteína BRCA2/genética , Neoplasias de la Mama/tratamiento farmacológico , Morfolinas/administración & dosificación , Neoplasias Ováricas/tratamiento farmacológico , Ftalazinas/administración & dosificación , Piperazinas/administración & dosificación , Adulto , Anciano , Aminopiridinas/farmacocinética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Relación Dosis-Respuesta a Droga , Femenino , Mutación de Línea Germinal , Humanos , Persona de Mediana Edad , Morfolinas/farmacocinética , Clasificación del Tumor , Recurrencia Local de Neoplasia/tratamiento farmacológico , Recurrencia Local de Neoplasia/genética , Recurrencia Local de Neoplasia/patología , Neoplasias Ováricas/genética , Neoplasias Ováricas/patología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Ftalazinas/farmacocinética , Piperazinas/farmacocinética , Inhibidores de Poli(ADP-Ribosa) Polimerasas/administración & dosificación , Poli(ADP-Ribosa) Polimerasas/genética
11.
Environ Sci Pollut Res Int ; 24(1): 725-731, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27752949

RESUMEN

Exposure to human antidepressants has been shown to disrupt locomotion and other foot-mediated mechanisms in aquatic snails. We tested the effect of three selective serotonin reuptake inhibitor (SSRI)- and one selective serotonin-norepinephrine reuptake inhibitor (SNRI)-type antidepressants on the righting response in the marine snail, Ilyanassa obsoleta. All four antidepressants (fluoxetine, sertraline, paroxetine, venlafaxine) significantly increased righting time compared with controls with an exposure time as short as 1 h. Dose responses were nonmonotonic with effects seen mainly at the lowest exposure concentrations and shortest duration. The lowest concentration to show an effect was 3.45 µg/L fluoxetine with a 2-h exposure period and is about 3.71 times higher than environmental concentrations. Our results highlight rapid disruption of another foot-mediated behavior in aquatic snails by SSRI-type antidepressants. We discuss these and other reported nonmonotonic dose responses caused by antidepressants in terms of the various possible physiological mechanisms of action in nontarget aquatic species.


Asunto(s)
Antidepresivos/toxicidad , Inhibidores Selectivos de la Recaptación de Serotonina/toxicidad , Inhibidores de Captación de Serotonina y Norepinefrina/toxicidad , Caracoles/efectos de los fármacos , Animales , Fluoxetina/toxicidad , Paroxetina/toxicidad , Sertralina/toxicidad , Caracoles/fisiología , Clorhidrato de Venlafaxina/toxicidad
12.
Oncogene ; 31(4): 446-57, 2012 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-21725359

RESUMEN

Identifying the spectrum of genetic alterations that cooperate with critical oncogenes to promote transformation provides a foundation for understanding the diversity of clinical phenotypes observed in human cancers. Here, we performed integrated analyses to identify genomic alterations that co-occur with oncogenic BRAF in melanoma and abrogate cellular dependence upon this oncogene. We identified concurrent mutational inactivation of the PTEN and RB1 tumor suppressors as a mechanism for loss of BRAF/MEK dependence in melanomas harboring (V600E)BRAF mutations. RB1 alterations were mutually exclusive with loss of p16(INK4A), suggesting that whereas p16(INK4A) and RB1 may have overlapping roles in preventing tumor formation, tumors with loss of RB1 exhibit diminished dependence upon BRAF signaling for cell proliferation. These findings provide a genetic basis for the heterogeneity of clinical outcomes in patients treated with targeted inhibitors of the mitogen-activated protein kinase pathway. Our results also suggest a need for comprehensive screening for RB1 and PTEN inactivation in patients treated with RAF and MEK-selective inhibitors to determine whether these alterations are associated with diminished clinical benefit in patients whose cancers harbor mutant BRAF.


Asunto(s)
Melanoma/genética , Mutación , Fosfohidrolasa PTEN/fisiología , Proteínas Proto-Oncogénicas B-raf/genética , Proteína de Retinoblastoma/fisiología , Proteínas Supresoras de Tumor/fisiología , Quinasas raf/fisiología , Animales , Quinasa 4 Dependiente de la Ciclina/genética , Humanos , Ratones , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Quinasas de Proteína Quinasa Activadas por Mitógenos/fisiología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Proteínas Proto-Oncogénicas B-raf/fisiología , Proteínas Proto-Oncogénicas c-akt/fisiología
13.
Eur J Clin Microbiol Infect Dis ; 31(4): 505-11, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21789605

RESUMEN

Staphylococcus aureus infections continue to pose a global public health problem. Frequently, this epidemic is driven by the successful spread of single S. aureus clones within a geographic region, but international travel has been recognized as a potential risk factor for S. aureus infections. To study the molecular epidemiology of S. aureus infections in the Caribbean, a major international tourist destination, we collected methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates from community-onset infections in the Dominican Republic (n = 112) and Martinique (n = 143). Isolates were characterized by a combination of pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) typing. In Martinique, MRSA infections (n = 56) were mainly caused by t304-ST8 strains (n = 44), whereas MSSA isolates were derived from genetically diverse backgrounds. Among MRSA strains (n = 22) from the Dominican Republic, ST5, ST30, and ST72 predominated, while ST30 t665-PVL+ (30/90) accounted for a substantial number of MSSA infections. Despite epidemiological differences in sample collections from both countries, a considerable number of MSSA infections (~10%) were caused by ST5 and ST398 isolates at each site. Further phylogenetic analysis suggests the presence of lineages shared by the two countries, followed by recent genetic diversification unique to each site. Our findings also imply the frequent import and exchange of international S. aureus strains in the Caribbean.


Asunto(s)
Pandemias , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Análisis por Conglomerados , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/microbiología , República Dominicana/epidemiología , Electroforesis en Gel de Campo Pulsado , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Masculino , Martinica/epidemiología , Persona de Mediana Edad , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Pacientes Ambulatorios , Staphylococcus aureus/genética , Adulto Joven
14.
Oncogene ; 28(31): 2773-83, 2009 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-19525976

RESUMEN

To address the biological heterogeneity of lung cancer, we studied 199 lung adenocarcinomas by integrating genome-wide data on copy number alterations and gene expression with full annotation for major known somatic mutations in this cancer. This showed non-random patterns of copy number alterations significantly linked to EGFR and KRAS mutation status and to distinct clinical outcomes, and led to the discovery of a striking association of EGFR mutations with underexpression of DUSP4, a gene within a broad region of frequent single-copy loss on 8p. DUSP4 is involved in negative feedback control of EGFR signaling, and we provide functional validation for its role as a growth suppressor in EGFR-mutant lung adenocarcinoma. DUSP4 loss also associates with p16/CDKN2A deletion and defines a distinct clinical subset of lung cancer patients. Another novel observation is that of a reciprocal relationship between EGFR and LKB1 mutations. These results highlight the power of integrated genomics to identify candidate driver genes within recurrent broad regions of copy number alteration and to delineate distinct oncogenetic pathways in genetically complex common epithelial cancers.


Asunto(s)
Adenocarcinoma/genética , Fosfatasas de Especificidad Dual/genética , Receptores ErbB/genética , Perfilación de la Expresión Génica , Neoplasias Pulmonares/genética , Fosfatasas de la Proteína Quinasa Activada por Mitógenos/genética , Mutación , Adenocarcinoma/patología , Línea Celular Tumoral , Proliferación Celular , Aberraciones Cromosómicas , Análisis por Conglomerados , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Femenino , Dosificación de Gen , Regulación Neoplásica de la Expresión Génica , Genes ras/genética , Estudio de Asociación del Genoma Completo , Humanos , Hibridación Fluorescente in Situ , Estimación de Kaplan-Meier , Neoplasias Pulmonares/patología , Masculino , Hibridación de Ácido Nucleico , Interferencia de ARN
15.
Br J Cancer ; 95(4): 425-30, 2006 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-16880794

RESUMEN

Molecular alterations in the prostate cancer proteome mediate the functional and phenotypic transformation from clinically localised to metastatic cancer, a transition that drives patient's mortality and challenges therapeutic intervention. A first approximation of differential proteomic alterations stratified by disease stage has yielded repertoires of potential diagnostic and prognostic markers, multiplex signatures of predictive value, and yield fundamental insight into molecular commonalities in cancer progression. Deciphering these causative proteomic alterations from the molecular noise will continue to mature our understanding of tumour biology and drive new computational and integrative approaches to model a system's view that accommodates the heterogeneity of prostate cancer progression.


Asunto(s)
Perfilación de la Expresión Génica , Proteínas de Neoplasias/metabolismo , Neoplasias de la Próstata/metabolismo , Biomarcadores de Tumor/análisis , Progresión de la Enfermedad , Humanos , Masculino , Modelos Biológicos , Metástasis de la Neoplasia/diagnóstico
16.
Oncogene ; 20(45): 6531-7, 2001 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-11641777

RESUMEN

While both nitric oxide synthase-2 (NOS-2) and low molecular weight GTPases, such as Ras and Rho, have been implicated in malignant transformation, the cross talk between these important proteins is ill understood. In this study we examined the ability of H-Ras, RhoA, RhoB and Rac1 to modulate cytokine-induced NOS2. In the normal human liver AKN-1 cell line and in the human non-small cell lung carcinoma cell line, A-549, the ability of the cytokines (INF-gamma, IL-1beta and TNF-alpha) to activate NOS-2 was blocked by activated L61-H-Ras whereas dominant negative N17-H-Ras enhanced NOS-2 activation. Consistent with this dominant negative Erk2 as well as a MEK inhibitor also enhanced cytokine activation of NOS-2. Furthermore, activated L63-RhoA blocked whereas activated V14-RhoB enhanced cytokine NOS-2 activation. Activated I115-Racl did not affect NOS-2 activation. These results demonstrate that the Ras/Erk and the Ras/RhoA pathways negatively regulate whereas RhoB enhances cytokine-induced NOS-2. This is the first demonstration that genes that promote malignant transformation such as Ras and RhoA inhibit, whereas genes with tumor suppressor activity such as RhoB enhance NOS2 induction.


Asunto(s)
Citocinas/farmacología , Hígado/metabolismo , Neoplasias Pulmonares/genética , Óxido Nítrico Sintasa/genética , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Proteínas de Unión al GTP rho/fisiología , Línea Celular , Genes Reporteros , Humanos , Hígado/efectos de los fármacos , Neoplasias Pulmonares/enzimología , Quinasas de Proteína Quinasa Activadas por Mitógenos/fisiología , Proteínas Quinasas Activadas por Mitógenos/fisiología , Mutación , Óxido Nítrico Sintasa de Tipo II , Proteínas Proto-Oncogénicas p21(ras)/genética , Activación Transcripcional , Transfección , Células Tumorales Cultivadas , Proteína de Unión al GTP rac1/fisiología , Proteína de Unión al GTP rhoA/fisiología , Proteína de Unión al GTP rhoB/fisiología
17.
Proc Natl Acad Sci U S A ; 98(15): 8638-43, 2001 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-11438703

RESUMEN

The human inducible nitric oxide synthase (hiNOS) gene is expressed in several disease states and is also important in the normal immune response. Previously, we described a cytokine-responsive enhancer between -5.2 and -6.1 kb in the 5'-flanking hiNOS promoter DNA, which contains multiple nuclear factor kappa beta (NF-kappa B) elements. Here, we describe the role of the IFN-Jak kinase-Stat (signal transducer and activator of transcription) 1 pathway for regulation of hiNOS gene transcription. In A549 human lung epithelial cells, a combination of cytokines tumor necrosis factor-alpha, interleukin-1 beta, and IFN-gamma (TNF-alpha, IL-1 beta, and IFN-gamma) function synergistically for induction of hiNOS transcription. Pharmacological inhibitors of Jak2 kinase inhibit cytokine-induced Stat 1 DNA-binding and hiNOS gene expression. Expression of a dominant-negative mutant Stat 1 inhibits cytokine-induced hiNOS reporter expression. Site-directed mutagenesis of a cis-acting DNA element at -5.8 kb in the hiNOS promoter identifies a bifunctional NF-kappa B/Stat 1 motif. In contrast, gel shift assays indicate that only Stat 1 binds to the DNA element at -5.2 kb in the hiNOS promoter. Interestingly, Stat 1 is repressive to basal and stimulated iNOS mRNA expression in 2fTGH human fibroblasts, which are refractory to iNOS induction. Overexpression of NF-kappa B activates hiNOS promoter-reporter expression in Stat 1 mutant fibroblasts, but not in the wild type, suggesting that Stat 1 inhibits NF-kappa B function in these cells. These results indicate that both Stat 1 and NF-kappa B are important in the regulation of hiNOS transcription by cytokines in a complex and cell type-specific manner.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Regulación Enzimológica de la Expresión Génica , FN-kappa B/metabolismo , Óxido Nítrico Sintasa/genética , Proteínas Proto-Oncogénicas , Transactivadores/metabolismo , Transcripción Genética , Sitios de Unión , Línea Celular , Proteínas de Unión al ADN/genética , Fibroblastos/citología , Fibroblastos/metabolismo , Genes Reporteros , Humanos , Interferón gamma/farmacología , Janus Quinasa 2 , Mutagénesis , FN-kappa B/genética , Óxido Nítrico Sintasa de Tipo II , Regiones Promotoras Genéticas , Proteínas Tirosina Quinasas/metabolismo , Factor de Transcripción STAT1 , Transducción de Señal , Transactivadores/genética
18.
J Surg Res ; 99(2): 258-64, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11469895

RESUMEN

BACKGROUND: The inducible nitric oxide synthase (iNOS) is strongly expressed following inflammatory stimuli. Adenosine 3',5'-cyclic monophosphate (cAMP) increases iNOS expression and activity in a number of cell types but decreases cytokine-stimulated iNOS expression in hepatocytes. The mechanisms for this effect are unknown. METHODS: Rat hepatocytes were stimulated with cytokines to induce iNOS and cultured with cAMP agonists dibutyryl-cAMP (dbcAMP), 8-bromo-cAMP, and forskolin (FSK). Nitric oxide synthesis was assessed by supernatant nitrite levels and iNOS expression was measured by Northern and Western blot analyses. Nuclear factor kappaB binding was assessed by electromobility shift assay. RESULTS: Cyclic AMP dose dependently decreased NO synthesis in response to a combination of proinflammatory cytokines or interleukin-1beta (IL-1beta) alone. The adenylate cyclase inhibitor SQ 22,536 increased cytokine- or IL-1beta-stimulated NO synthesis. dbcAMP decreased iNOS mRNA expression and iNOS protein expression. Both dbcAMP and glucagon decreased iNOS promoter activity in rat hepatocytes transfected with the murine iNOS promoter and decreased DNA binding of the transcription factor NF-kappaB. CONCLUSION: These data suggest that cAMP is important in hepatocyte iNOS expression and agents that alter cAMP levels may profoundly alter the response of hepatocytes to inflammatory stimuli through effects onthe iNOS promoter region and NF-kappaB.


Asunto(s)
Adenina/análogos & derivados , AMP Cíclico/farmacología , Hepatocitos/enzimología , FN-kappa B/metabolismo , Óxido Nítrico Sintasa/genética , 8-Bromo Monofosfato de Adenosina Cíclica/farmacología , Adenina/farmacología , Inhibidores de Adenilato Ciclasa , Adenilil Ciclasas/metabolismo , Animales , Bucladesina/farmacología , Células Cultivadas , Colforsina/farmacología , Inhibidores Enzimáticos/farmacología , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/fisiología , Glucagón/farmacología , Hepatocitos/citología , Interleucina-1/farmacología , Masculino , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/enzimología , Óxido Nítrico Sintasa de Tipo II , Regiones Promotoras Genéticas/fisiología , Arteria Pulmonar/citología , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Sistemas de Mensajero Secundario/fisiología , Sepsis/metabolismo , Sepsis/fisiopatología , Transfección
19.
Shock ; 13(6): 413-24, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10847627

RESUMEN

In critically ill patients, the human inducible nitric oxide synthase (iNOS) gene is expressed in nearly every organ and has been shown to be associated with the refractory hypotension of septic and hemorrhagic shock. The molecular regulation of iNOS expression is complex and occurs at multiple sites in the gene expression pathway. Work in our laboratory has demonstrated that a combination of cytokines synergistically activate iNOS expression, which has resulted in the cloning of the first human iNOS gene from cytokine-stimulated hepatocytes. In addition, we have demonstrated that iNOS expression is transcriptionally regulated and that the functional promoter elements are located upstream of -4.7 kilobases (kb) within a unique enhancer region containing four functional nuclear factor kappa B elements. These results contrast markedly with the murine iNOS promoter, where only 1.0 kb of 5'-flanking sequence is required for lipopolysaccharide and cytokine responsiveness. Furthermore, numerous mechanisms have evolved to down-regulate iNOS expression. By elucidating these mechanisms, therapeutic strategies to govern iNOS expression may be developed.


Asunto(s)
Regulación Enzimológica de la Expresión Génica , Óxido Nítrico Sintasa/genética , Células 3T3/enzimología , Animales , Elementos de Facilitación Genéticos , Inducción Enzimática/efectos de los fármacos , Genes , Sustancias de Crecimiento/fisiología , Humanos , Hígado/enzimología , Ratones , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa/biosíntesis , Óxido Nítrico Sintasa de Tipo II , Especificidad de Órganos , Transducción de Señal , Especificidad de la Especie , Factores de Transcripción/fisiología , Transcripción Genética , Factor de Crecimiento Transformador beta/fisiología
20.
J Vasc Surg ; 30(6): 1052-9, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10587389

RESUMEN

OBJECTIVE: The compression of femoral artery pseudoaneurysms is a time consuming, painful, and sometimes unsuccessful procedure. Thrombin injection has been advocated as a superior alternative. In this study, we compare our experiences with both techniques. METHODS: All the records of femoral artery false aneurysms that were treated in the vascular laboratory from January 1996 to April 1999 were retrospectively reviewed. Treatment with ultrasound scan-guided compression was compared with treatment with dilute thrombin injection (100 U/mL). RESULTS: Both groups had similar demographics and aneurysm sizes (P >.2). Of the pseudoaneursyms, 88% were caused by cardiac catheterization and the others were the results of femoral artery access for cardiac surgery (6%), arteriography (5%), and renal dialysis (1%). Compression was successful in 25 of 40 patients (63%). Nine persistent aneurysms necessitated operation, and six were treated successfully with thrombin injection. Primary thrombin injection successfully obliterated 21 pseudoaneurysms in 23 patients. Overall, 27 of 29 pseudoaneurysms were treated successfully with thrombin injection (93%). Thrombosis occurred within seconds of the thrombin injection and required, on average, 300 units of thrombin (100 to 600 units). The patients who underwent successful compression required an average of 37 minutes of compression (range, 5 to 70 minutes) and required analgesia on several occasions. No patients in the thrombin group required analgesia or sedation. Neither group had complications. A cost analysis shows that thrombin treatment results in considerable savings in vascular laboratory resource use but not in overall hospital expenditures. CONCLUSION: Ultrasound scan-guided thrombin injection is a safe, fast, and painless procedure that completely obliterates femoral artery pseudoaneurysms. The shift from compressive therapy to thrombin injection reduces vascular laboratory use and is less expensive, although it does not significantly impact hospital costs.


Asunto(s)
Aneurisma Falso/terapia , Arteria Femoral , Técnicas Hemostáticas , Trombina/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma Falso/diagnóstico por imagen , Femenino , Arteria Femoral/diagnóstico por imagen , Humanos , Inyecciones Intraarteriales , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Presión , Estudios Retrospectivos , Resultado del Tratamiento , Ultrasonografía
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