Usefulness of ploidy, AgNOR and immunocytochemistry for differentiating benign and malignant cells in serous effusions.

OBJECTIVE: The objective of this study was to establish the value of different markers in differentiating reactive mesothelial cells from metastatic adenocarcinomatous cells in serous effusions (SE). METHODS: Forty-five SE were processed for morphological examination (Papanicolaou stain), assessment of ploidy, AgNOR counting and immunocytochemical assay of carcinoembryonic antigen (CEA), epithelial membrane antigens (EMA), Ber-EP4 and Leu-M1. Ploidy was established in an image-analyser in smears stained by the Feulgen stain method. AgNOR dots were counted in the smears stained with the silver nitrate assay for non-histone proteins present in the nucleolar organizer region. CEA, EMA, Ber-EP4 and Leu-M1 were evaluated by immunocytochemistry using the streptavidin-biotin complex method. RESULTS: All the smears with positive cytology were aneuploid. Three false negatives by morphological studies were aneuploid, with AgNOR values in two of them corresponding to the neoplastic group. CEA and Leu-M1 showed a low specificity; EMA and Ber-EP4 showed moderate sensitivity. CONCLUSIONS: The assessment of ploidy and the study of AgNOR were better methods than immunocytochemistry for distinguishing between reactive mesothelial cells and adenocarcinomatous cells in serous fluid.

Medicina genómica: aplicaciones del polimorfismo de un nucleótido y micromatrices de ADN / Genomic medicine: polymorphisms and microarray applications

This update shows new concepts related to the significance of DNA variations among individuals, as well as to their detection by using a new technology. The sequencing of the human genome is only the beginning of what will enable us to understand genetic diversity. The unit of DNA variability is the polymorphism of a single nucleotide (SNP). At present, studies on SNPs are restricted to basic research but the large number of papers on this subject makes feasible their entrance into clinical practice. We illustrate here the use of SNPs as molecular markers in ethnical genotyping, gene expression in some diseases and as potential targets in pharmacological response, and also introduce the technology of arrays. Microarrays experiments allow the quantification and comparison of gene expression on a large scale, at the same time, by using special chips and array designs. Conventional methods provide data from up to 20 genes, while a single microarray may provide information about thousands of them simultaneously, leading to a more rapid and accurate genotyping. Biotechnology improvements will facilitate our knowledge of each gene sequence, the frequency and exact location of SNPs and their influence on cellular behavior. Although experimental efficiency and validity of results from microarrays are still controversial, the knowledge and characterization of a patient's genetic profile will lead, undoubtedly, to advances in prevention, diagnosis, prognosis and treatment of human diseases.

Esta actualización tiene por objeto difundir un nuevo enfoque de las variaciones del ADN entre individuos y comentar las nuevas tecnologías para su detección. La secuenciación total del genoma humano es el comienzo para conocer la diversidad genética. La unidad de medida reconocida de esta variabilidades el polimorfismo de un solo nucleótido (single nucleotide polymorphism o SNP). El estudio de los SNPs está restringido a la investigación pero las numerosas publicaciones sobre el tema hacen vislumbrar su entrada en la práctica clínica. Se presentan ejemplos del uso de SNPs como marcadores moleculares en la genotipificación étnica, la expresión génica de enfermedades y como potenciales blancos farmacológicos. Se comenta la técnica de las matrices (arrays) que facilita el estudio de múltiples secuencias de genes mediante chips de diseño específico. Los métodos convencionales analizan hasta un máximo de 20 genes, mientras que una sola micromatriz provee información sobre decenas de miles de genes simultáneamente con una genotipificación rápida y exacta. Los avances de la biotecnología permitirán conocer, además de la secuencia de cada gen, la frecuencia y ubicación exacta de los SNPs y su influencia en los comportamientos celulares. Si bien la validez de los resultados y la eficiencia de las micromatrices son aún controvertidos, el conocimiento y caracterización del perfil genético de un paciente impulsará seguramente un cambio radical en la prevención, diagnóstico, pronóstico y tratamiento de las enfermedades humanas.

Medicina genómica: aplicaciones del polimorfismo de un nucleótido y micromatrices de ADN / Genomic medicine: polymorphisms and microarray applications

This update shows new concepts related to the significance of DNA variations among individuals, as well as to their detection by using a new technology. The sequencing of the human genome is only the beginning of what will enable us to understand genetic diversity. The unit of DNA variability is the polymorphism of a single nucleotide (SNP). At present, studies on SNPs are restricted to basic research but the large number of papers on this subject makes feasible their entrance into clinical practice. We illustrate here the use of SNPs as molecular markers in ethnical genotyping, gene expression in some diseases and as potential targets in pharmacological response, and also introduce the technology of arrays. Microarrays experiments allow the quantification and comparison of gene expression on a large scale, at the same time, by using special chips and array designs. Conventional methods provide data from up to 20 genes, while a single microarray may provide information about thousands of them simultaneously, leading to a more rapid and accurate genotyping. Biotechnology improvements will facilitate our knowledge of each gene sequence, the frequency and exact location of SNPs and their influence on cellular behavior. Although experimental efficiency and validity of results from microarrays are still controversial, the knowledge and characterization of a patients genetic profile will lead, undoubtedly, to advances in prevention, diagnosis, prognosis and treatment of human diseases.(AU)

Esta actualización tiene por objeto difundir un nuevo enfoque de las variaciones del ADN entre individuos y comentar las nuevas tecnologías para su detección. La secuenciación total del genoma humano es el comienzo para conocer la diversidad genética. La unidad de medida reconocida de esta variabilidades el polimorfismo de un solo nucleótido (single nucleotide polymorphism o SNP). El estudio de los SNPs está restringido a la investigación pero las numerosas publicaciones sobre el tema hacen vislumbrar su entrada en la práctica clínica. Se presentan ejemplos del uso de SNPs como marcadores moleculares en la genotipificación étnica, la expresión génica de enfermedades y como potenciales blancos farmacológicos. Se comenta la técnica de las matrices (arrays) que facilita el estudio de múltiples secuencias de genes mediante chips de diseño específico. Los métodos convencionales analizan hasta un máximo de 20 genes, mientras que una sola micromatriz provee información sobre decenas de miles de genes simultáneamente con una genotipificación rápida y exacta. Los avances de la biotecnología permitirán conocer, además de la secuencia de cada gen, la frecuencia y ubicación exacta de los SNPs y su influencia en los comportamientos celulares. Si bien la validez de los resultados y la eficiencia de las micromatrices son aún controvertidos, el conocimiento y caracterización del perfil genético de un paciente impulsará seguramente un cambio radical en la prevención, diagnóstico, pronóstico y tratamiento de las enfermedades humanas.(AU)

[Serum testosterone: a possible marker for colorectal cancer]. / Testosterona sérica: posible marcador en el cáncer colorrectal.

A reduction of circulating testosterone has been reported in lung, stomach and pancreatic carcinoma. In order to evaluate the concentration of this hormone in patients with colorectal cancer, we studied 58 men with histologically confirmed disease. Seric testosterone, estradiol and carcinoembryogenic antigen were simultaneously measured in 24 patients under pre-surgical evaluation (group I) and in 34 patients after surgical resection (group II). The results were compared with a control group carrying benign gastrointestinal pathologies. According to the Kruskal-Wallis test, the testosterone level in cancer groups was significantly lower than in the control group (p < 0.0001). We have also observed a statistical significance between subgroups I and II compared to the control group (p < 0.001), while no conspicuous differences were perceived in estradiol concentrations between benign and cancer groups. Decreased serum levels of testosterone were found in 69% of patients with colon or rectal carcinoma and 56.9% of them had raised levels of carcinoembryonic antigen. The combined determination of both biomarkers increase to 86.2% the sensitivity of tumor screening compared with a single detection. Our results suggest that the combination of testosterone and carcinoembryonic antigen enhances the efficiency of tumor screening. We conclude that the evaluation of circulating testosterone could be a new and more sensitive assay for diagnosis and follow-up of colorectal carcinoma in males, specially in patients with normal levels of carcinoembryonic antigen.

Testosterona sérica: posible marcador en el cáncer colorrectal. / [Serum testosterone: a possible marker for colorectal cancer]

A reduction of circulating testosterone has been reported in lung, stomach and pancreatic carcinoma. In order to evaluate the concentration of this hormone in patients with colorectal cancer, we studied 58 men with histologically confirmed disease. Seric testosterone, estradiol and carcinoembryogenic antigen were simultaneously measured in 24 patients under pre-surgical evaluation (group I) and in 34 patients after surgical resection (group II). The results were compared with a control group carrying benign gastrointestinal pathologies. According to the Kruskal-Wallis test, the testosterone level in cancer groups was significantly lower than in the control group (p < 0.0001). We have also observed a statistical significance between subgroups I and II compared to the control group (p < 0.001), while no conspicuous differences were perceived in estradiol concentrations between benign and cancer groups. Decreased serum levels of testosterone were found in 69

of patients with colon or rectal carcinoma and 56.9

of them had raised levels of carcinoembryonic antigen. The combined determination of both biomarkers increase to 86.2

the sensitivity of tumor screening compared with a single detection. Our results suggest that the combination of testosterone and carcinoembryonic antigen enhances the efficiency of tumor screening. We conclude that the evaluation of circulating testosterone could be a new and more sensitive assay for diagnosis and follow-up of colorectal carcinoma in males, specially in patients with normal levels of carcinoembryonic antigen.