RESUMEN
Although dysregulation of tight junction (TJ) proteins is observed in epithelial malignancy, their participation in epithelial transformation is poorly understood. Recently we demonstrated that expression of oncogenic Raf 1 in Pa4 epithelial cells disrupts TJs and induces an oncogenic phenotype by downregulating expression of the TJ protein, occludin. Here we report the mechanism by which Raf 1 regulates occludin expression. Raf 1 inhibited occludin transcription by repressing a minimal segment of the occludin promoter in concert with upregulation of the transcriptional repressor, Slug without influencing the well-documented transcriptional repressor, Snail. Overexpression of Slug in Pa4 cells recapitulated the effect of Raf 1 on occludin expression, and depletion of Slug by small interfering RNA abrogated the effect of Raf 1 on occludin. Finally, chromatin immunoprecipitation assays and site-directed mutagenesis demonstrated a direct interaction between Slug and an E-box within the minimal Raf 1-responsive segment of the occludin promoter. These findings support a role of Slug in mediating Raf 1-induced transcriptional repression of occludin and subsequent epithelial to mesenchymal transition.
Asunto(s)
Proteínas de la Membrana/genética , Proteínas Proto-Oncogénicas c-raf/metabolismo , Proteínas Represoras/metabolismo , Uniones Estrechas/metabolismo , Factores de Transcripción/metabolismo , Animales , Inmunoprecipitación de Cromatina , Regulación hacia Abajo , Elementos E-Box , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas de la Membrana/análisis , Proteínas de la Membrana/metabolismo , Ocludina , Ratas , Factores de Transcripción de la Familia Snail , Uniones Estrechas/química , Dedos de ZincAsunto(s)
Disparidad de Par Base , ADN/química , Oligonucleótidos/química , Secuencia de Bases , TermodinámicaRESUMEN
To determine if use of a physician chart reminder improves the rate of physician-initiated discussion and subsequent completion of advance directives (ADs) in patients with AIDS, a controlled study was conducted with 74 patients with AIDS and ten physicians providing primary care at a university-based hospital clinic. Chart reminders were placed on medical records of intervention patients at each primary care clinic visit for six months. Twelve out of 39 (31%) reminder group patients, but only three out of 35 (9%, p = 0.02) control patients underwent AD discussion with physicians. Further, more subjects in the reminder group completed ADs (28% versus 9%, p = 0.03). Controlling for demographic and clinical factors, only assignment to reminder group was associated with discussion and completion of ADs. Physician-level analysis showed that the effect was physician-dependent. Physician chart reminders are an effective tool for promoting discussion and completion of ADs in patients with AIDS although the effect is physician-dependent.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/psicología , Directivas Anticipadas , Sistemas Recordatorios , Adulto , Estudios de Casos y Controles , Promoción de la Salud , Humanos , Registros Médicos , Cuerpo Médico de Hospitales , Atención Primaria de SaludRESUMEN
BACKGROUND: Patients infected with HIV value both longevity and health. OBJECTIVE: To understand how HIV-infected patients value their health. DESIGN: Interview study. SETTING: Regional treatment center for HIV. PATIENTS: 51 patients with HIV infection. MEASUREMENTS: Life-satisfaction, health rating, time-tradeoff, and standard-gamble scores. RESULTS: Of the 51 patients, 49% (95% CI, 35% to 63%) said that their life was better currently than it was before they contracted HIV infection; only 29% said that life was currently worse. The mean (+/- SD) time-tradeoff score was 0.95 +/- 0.10, indicating that, on average, patients would give up no more than 5% of their remaining life expectancy in their current state of health in exchange for a shorter but healthy life. The average health rating score was 71.0 +/- 18.7 on a scale of 0 to 100, and the average standard-gamble score was 0.80 +/- 0.27. Factors contributing to life satisfaction and time-tradeoff scores included spirituality and having children. CONCLUSION: Many patients with HIV have a strong will to live, and many feel that life with HIV is better than it was before they became infected.
Asunto(s)
Infecciones por VIH/psicología , Calidad de Vida , Adulto , Anciano , Interpretación Estadística de Datos , Femenino , Estado de Salud , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Religión , Espiritualidad , Encuestas y Cuestionarios , Valor de la VidaRESUMEN
The purpose of this study was to evaluate the intercorrelation between three genetic assays in 112 subjects. The group was pooled from two originally separate but homogeneous subgroups of 56 persons each. Procedures included assays for hprt mutant frequencies, micronuclei in human lymphocytes, and mutations at the glycophorin A (gpa) loci. We found no statistically significant or biologically important intercorrelations among the three biomarkers. We did, however, observe significant correlations between log(e) hprt mutant frequency and cloning efficiency (inverse correlation for these 2 variables), age and log(e) hprt mutant frequency, an inverse relationship between cloning efficiency and age, and an important differential sex effect favoring a greater micronuclei frequency in females than males. No significant correlations between the covariates of interest and glycophorin A variant frequencies NN or NO were observed. Using multivariable linear regression, age was found to account for the majority of the variability in hprt mutant frequency (greater than sex and/or smoking); for micronuclei data, only sex contributed a statistically significant and biologically important proportion to the total variation. We conclude that despite observing no significant intercorrelations between the three assays performed simultaneously from the same individuals in a large population database, a significant correlation between age and hprt mutant frequency and an inverse association between cloning efficiency and hprt do exist; furthermore, we verified the strong differential sex-specific effect on micronucleus frequencies.
Asunto(s)
Monitoreo del Ambiente/métodos , Glicoforinas/genética , Hipoxantina Fosforribosiltransferasa/genética , Pruebas de Mutagenicidad , Mutación , Factores de Edad , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Biomarcadores , Femenino , Frecuencia de los Genes , Variación Genética , Homocigoto , Humanos , Linfocitos/citología , Masculino , Pruebas de Micronúcleos , Persona de Mediana Edad , Fenotipo , Análisis de Regresión , Reproducibilidad de los Resultados , Fumar , Encuestas y CuestionariosRESUMEN
The objective of this study was to examine if individuals living near a uranium processing site have greater mutagenic damage, as measured by three mutagenicity assays, compared with subjects unexposed to any nuclear facilities. The design was a cross-sectional exploratory analysis of 112 subjects; 56 volunteer residents were from within a 5-mile radius of the Fernald Uranium Processing site and 56 'control' subjects were from a geographically separate area unexposed to any known uranium emissions. The groups were constrained to be similar in age and sex composition. The main outcome measures were three human somatic gene mutation assays consisting of the HPRT T-lymphocyte cloning assay to measure 6-thioguanine resistant lymphocytes; the glycophorin A assay to detect the loss of expression of the M or N allele; and the micronucleus assay as a marker of chromosomal damage. The results showed no statistically significant or quantitatively important differences between groups for all three mutagenicity assays; only the unselected cloning efficiency was statistically significantly different between groups (0.42 +/- 0.16 for the Fernald versus 0.35 +/- 0.12 for the comparison groups). In both groups, age was significantly related to HPRT mutant frequency, with a 1.25% rate of increase in mutant frequencies for each 1-year gain of age in the Fernald group and a 1.12% rate of increase in mutant frequencies for each 1-year gain of age in the comparison group. For the micronucleus data, females had a greater mean micronucleus frequency than males. In addition, smokers had an increased mean ln (natural logarithm) HPRT mutant frequency (3.06 +/- 0.14 for current smokers compared with a mean of 2.72 +/- 0.05 for non-current (i.e. never plus former) smokers). Our results are consistent with the previously reported association between sex type and micronucleus frequency, the known relationship between age and T-lymphocyte cloning efficiency and age and HPRT mutant frequency, and verify the wide inter-subject variability for the latter. Finally, we conclude that at a population level, the relationships between current cigarette use and HPRT mutant frequency, and sex type and micronucleus frequency, are stronger than is the association between geographic proximity to a uranium processing site and mutagenic abnormalities.
Asunto(s)
Mutación , Uranio/efectos adversos , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Exposición a Riesgos Ambientales , Monitoreo del Ambiente , Femenino , Glicoforinas/genética , Humanos , Hipoxantina Fosforribosiltransferasa/genética , Masculino , Pruebas de Micronúcleos , Persona de Mediana Edad , Pruebas de Mutagenicidad , Ohio , Dosis de Radiación , Residuos Radiactivos/efectos adversosRESUMEN
Antiretroviral therapy with zidovudine is indicated in patients with CD4 cell counts below 500 per mm3 (500 x 10(6) per L). Patients intolerant of zidovudine and those with advanced human immunodeficiency virus infection may benefit from newer antiretroviral agents, such as didanosine (ddl) or zalcitabine (ddC). Prophylactic therapy for Pneumocystis carinii pneumonia is indicated in patients with CD4 cell counts below 200 per mm3 (200 x 10(6) per L), in patients with CD4 cell counts less than 20 percent of the total lymphocytes and in patients with a prior history of P. carinii infection. In addition, prophylaxis is often initiated if thrush is present, even when CD4 cell counts are above 200. Trimethoprim-sulfamethoxazole is the drug of choice for Pneumocystis prophylaxis; aerosolized pentamidine is reserved for patients unable to tolerate trimethoprim-sulfamethoxazole. Oral candidiasis is treated with nystatin suspension, clotrimazole troches, ketoconazole or fluconazole, with fluconazole used for resistant or more invasive infection. Finally, acyclovir is used to treat herpes zoster or herpes simplex virus infection.