RESUMEN
OBJECTIVES: Despite more than 40 years of experience performing the Bethesda assay (BA), poor intra- and interlaboratory precision remains the biggest laboratory challenge to date. METHODS: The BA procedure was modeled using stochastic simulation techniques to determine the precision of the BA up to dilutions of 1:4,096, to estimate the minimum significant relative change at various inhibitor titers, and to understand the laboratory procedural variables that could significantly affect the performance of the BA at high dilutions. RESULTS: Selecting the lowest dilution tube with a residual activity closest to 25% for calculating the reported Bethesda titer (BT), using a factor activity assay with a coefficient of variation less than or equal toâ 7.5% in the range of 15% to 50% factor activity level, performing the factor activity measurement in replicates, and minimizing pipette volumetric error resulted in the lowest imprecision in the reported BT. The factor neutralization kinetics of the inhibitor appear to have little impact on the precision of the assay if the incubation time is greater than 90 minutes. CONCLUSIONS: This in silico model will assist future laboratory efforts in standardizing the quantification of specific coagulation factor inhibitors and improving the precision of the reported results.
Asunto(s)
Pruebas de Coagulación Sanguínea/normas , Simulación por Computador , Pruebas de Coagulación Sanguínea/métodos , Humanos , Sensibilidad y EspecificidadRESUMEN
Many patients with hilar cholangiocarcinoma (HC) have a poor prognosis. Snail, a transcription factor and E-cadherin repressor, is a novel prognostic factor in many cancers. The aim of this study was to evaluate the relationship between snail and E-cadherin protein expression and the prognostic significance of snail expression in HC. We examined the protein expression of snail and E-cadherin in HC tissues from 47 patients (22 males and 25 females, mean age 61.2 years) using immunohistochemistry and RT-PCR. Proliferation rate was also evaluated in the same cases by the MIB1 index. High, low and negative snail protein expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively, and 40.4% (19/47) cases showed reduced E-cadherin protein expression in HC samples. No significant correlation was found between snail and E-cadherin protein expression levels (P = 0.056). No significant correlation was found between snail protein expression levels and gender, age, tumor grade, vascular or perineural invasion, nodal metastasis and invasion, or proliferative index. Cancer samples with positive snail protein expression were associated with poor survival compared with the negative expresser groups. Kaplan-Meier curves comparing different snail protein expression levels to survival showed highly significant separation (P < 0.0001, log-rank test). With multivariate analysis, only snail protein expression among all parameters was found to influence survival (P = 0.0003). We suggest that snail expression levels can predict poor survival regardless of pathological features and tumor proliferation. Immunohistochemical detection of snail protein expression levels in routine sections may provide the first biological prognostic marker.
Asunto(s)
Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de los Conductos Biliares/metabolismo , Conductos Biliares Intrahepáticos/metabolismo , Colangiocarcinoma/metabolismo , Factores de Transcripción/metabolismo , Biomarcadores de Tumor/metabolismo , Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/patología , Conductos Biliares Intrahepáticos/patología , Cadherinas/metabolismo , Colangiocarcinoma/mortalidad , Colangiocarcinoma/patología , Inmunohistoquímica , Estimación de Kaplan-Meier , Estadificación de Neoplasias , Pronóstico , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Many patients with hilar cholangiocarcinoma (HC) have a poor prognosis. Snail, a transcription factor and E-cadherin repressor, is a novel prognostic factor in many cancers. The aim of this study was to evaluate the relationship between snail and E-cadherin protein expression and the prognostic significance of snail expression in HC. We examined the protein expression of snail and E-cadherin in HC tissues from 47 patients (22 males and 25 females, mean age 61.2 years) using immunohistochemistry and RT-PCR. Proliferation rate was also evaluated in the same cases by the MIB1 index. High, low and negative snail protein expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively, and 40.4% (19/47) cases showed reduced E-cadherin protein expression in HC samples. No significant correlation was found between snail and E-cadherin protein expression levels (P = 0.056). No significant correlation was found between snail protein expression levels and gender, age, tumor grade, vascular or perineural invasion, nodal metastasis and invasion, or proliferative index. Cancer samples with positive snail protein expression were associated with poor survival compared with the negative expresser groups. Kaplan-Meier curves comparing different snail protein expression levels to survival showed highly significant separation (P < 0.0001, log-rank test). With multivariate analysis, only snail protein expression among all parameters was found to influence survival (P = 0.0003). We suggest that snail expression levels can predict poor survival regardless of pathological features and tumor proliferation. Immunohistochemical detection of snail protein expression levels in routine sections may provide the first biological prognostic marker.
Asunto(s)
Neoplasias de los Conductos Biliares/metabolismo , Conductos Biliares Intrahepáticos/metabolismo , Biomarcadores de Tumor/metabolismo , Colangiocarcinoma/metabolismo , Factores de Transcripción/metabolismo , Neoplasias de los Conductos Biliares/mortalidad , Neoplasias de los Conductos Biliares/patología , Conductos Biliares Intrahepáticos/patología , Cadherinas/metabolismo , Colangiocarcinoma/mortalidad , Colangiocarcinoma/patología , Femenino , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factores de Transcripción de la Familia SnailRESUMEN
Phytochemical investigation of the leaves of Trichilia connaroides afforded 12 new limonoids with phragmalin- (1-11) and mexicanolide-type skeletons (12). The structures of these limonoids, including the absolute configuration of 3, were determined by spectroscopic analysis. Compounds 6 and 8 showed moderate cytotoxicity against HL-60 cells.