Alteraciones cromosómicas en anestésistas del Hospital Universitario de Maracaibo agosto 1996-julio 1997 / Chromosomic alterations in female anesthetist working at the Maracaibo University Hospital (HUM)

Las anestesiólogas que trabajan en los quirófano del HUM (Hospital Universitario de Maracaibo), están expuestas a agentes mutagénicos, gases anestésicos como óxido nitroso, halotano, enflurano y óxido de etileno utilizado en la esterilización de equipos quirúrgicos. Estos gases influyen en la división celular prolongando las fases G1 y G2, inhiben la síntesis de ácido nucleicos, intervienen en la mitosis entre la profase y la anafase. El óxido de etileno, en el hombre induce aberraciones cromosómicas e intercambio de cromátidas hermanas en linfocitos y es considerada como posible carcinógeno, en estudios epidemiológicos realizado con humanos expuestos. En los últimos cinco años se presentó un aumento en el número de abortos y nacidos vivos con malformaciones congénitas en las profesionales anestesistas en el HUM. El objetivo del estudio fue el de demostrar que los agentes anestésicos utilizados determinan daños genotóxicos en las anestesistas expuestas cronicamente, empleando como punto final a las alteraciones cromosómicas. La muestra la constituyeron 21 anestesiólogas, con edad promedio de 40 años, el 50 por ciento tiene más de 5 años de exposición, el 30 por ciento presentó antecedentes de abortos y el 15 por ciento hijos con malformaciones congénitas. Se les práctico estudio cromosómico utilizando la técnica de cultivo en linfocitos humanos con Bandas G. Los resultados mostraron un 55 por ciento de rupturas cromosómicas a nivel de los cromosomas 2 y 3 con mayor frecuecia, y un 100 por ciento de la muestra presentó endorreduplicaciones, con un promedio de 3 por cariotipo. El grupo control presentó un 6 por ciento de endorreduplicaciones, con un promedio de por cariotipo. Esto evidencia daño genotóxico en el grupo expuesto crónicamente a los agentes antes señalados y va depender del mecanismo de reparación del ADN en cada individuo

Baixa estatura na infancia e sindrome de Turner: uma associacao mais frequente do que se supoe / Short stature and Turner syndrome: an association more frequent than expected

A sindrome de Turner e uma causa bem conhecida de baixa estatura em criancas do sexo feminino, mas sua frequencia entre essas pacientes deve variar em diferentes populacoes. O estudo citogenetico de 38 meninas com baixa estatura e bom desenvolvimento neuropsicomotor, sem levar em consideracao a existencia ou nao de sinais dismorficos, revelou que pelo menos uma em cada oito sao portadoras da sindrome de Turner. Essa e uma frequencia inesperadamente alta numa populacao amplamente sujeita a fatores ambientais adversos que determinam deficiencia de crescimento

Detection of chromosome aberrations in interphase nuclei using fluorescence in situ hybridization technique

We report here several experiences of interphase cytogenetics, using fluorescence in situ hybridization (FISH) technique, for the detection of chromosome aberrations. FISH, using alpha satellite specific probes of 18, X, Y chromosomes, was done in interphase nuclei from peripheral blood of patients with Edwards' syndrome, Klinefelter's syndrome and Turner's syndrome with healthy male and female controls, respectively. The distributions of fluorescent signals in 100 interphase nuclei were well correlated with metaphase findings. Nowadays FISH plays an increasingly important role in a variety of research areas, including cytogenetics, prenatal diagnosis, tumor biology, gene amplification and gene mapping.

A comparative study on aberrations of chromosome 17 and proliferating cell fraction in lung cancer

To better understand the relationship between specific chromosome changes found in human lung tumors and their phenotypic consequences a the tissue level, an in situ hybridization (ISH) procedure of chromosome 17 and immunohistochemistry of proliferating cell nuclear antigen (PCNA) were done. The deparaffinized sections were stained with pericentromeric probes for chromosome 17 and an immunohistochemical study of a monoclonal antibody against PCNA were performed. The numbers of chromosome signals were than compared with the positivity of PCNA expression. The mean numbers of chromosome were 1.62 in normal lymphocytes and 2.48 in lung cancer cells. Tumors showed a high mean positivity of PCNA of 43.4%. Mean PCNA expression was higher in squamous carcinomas than in adenocarcinomas (p<0.05). A linear correlation between numbers of ISH signals and PCNA expression was not demonstrated, but there was a tendency of increasing PCNA positivity according to increasing numbers of ISH signals in adenocarcinomas of the lung and the tumor tissues which were over 50% positive PCNA expression. There was no linear correlation between numbers of ISH signals, PCNA positivity and tumor stages, and keratinization of squamous cell lung cancer. These results suggest that ISH will prove to bo an important tool for determining the underlying genetic basis for tissue phenotypic heterogeneity by allowing genetic determinations to be made on paraffin-embedded tissue sections where histologic architecture is preserved, and immunohistochemical nuclear staining with anti-PCNA on routinely processed tissue is a simple technique for the assessment of proliferation in non-small cell lung carcinoma.