Biomarkers of susceptibility and effect in car painters exposed to organic solvents / Biomarcadores de susceptibilidad y efecto en pintores de carros expuestos a solventes orgánicos

Abstract Introduction: Car painters are routinely exposed to organic solvents classified as carcinogenic and mutagenic substances. Objective: To characterize the population susceptibility and evaluate the genotoxic effects of exposure to organic solvents. Methods: A cross-sectional study comparing a group of car painters exposed to organic solvents with a non-exposed group. CYP2E1 polymorphisms and the presence of micronuclei in lymphocytes were determined. Results: One hundred twenty-two workers participated in the study: 62 who worked in car paint shops and were exposed to solvents, and 60 who were not exposed. There were statistically significant differences between the two groups regarding micronucleated cells and nucleoplasmic bridges frequencies (p=0.042 and p=0.046, respectively; exact likelihood ratio). Significant differences were found at the interaction between the CYP2E1 genotype c1c1 and occupational exposure to solvents, with higher frequencies of micronuclei (p= 0.013) and micronucleated cells (p= 0.015). However, when the frequencies of micronuclei, micronucleated cells and nucleoplasmic bridges in the exposure group were compared between the c1c1 and c2c2/c1c2 allele groups of the CYP2E1 polymorphism, statistically significant differences were found. Conclusions: This study confirms that when workers with CYP2E1 polymorphisms, specifically the c1c1 genotype, are exposed to organic solvents, they are more likely to have somatic cell mutations, a condition associated with increased susceptibility to diseases such as cancer

Resumen Introducción: Los pintores de vehículos automotores están rutinariamente expuestos a agentes como los solventes orgánicos, capaces de producir efectos mutágenos y carcinógenos. Objetivo: Caracterizar la susceptibilidad poblacional y evaluar los efectos genotóxicos debidos a la exposición a solventes orgánicos. Métodos: Estudio de corte transversal que comparó a un grupo de pintores de carros expuestos a solven tes orgánicos con un grupo de personas no expuestas. Fueron determinados tanto los polimorfismos de CYP2E1 como la presencia de micronúcleos en linfocitos. Resultados: Participaron 122 personas, 62 trabajadores de talleres de pintura de autos expuestos a solventes y 60 personas no expuestas. Con relación al cuestionario Q 16, 32% de los expuestos refirieron síntomas sugestivos de neurotoxicidad. Las frecuencias de células micronucleadas y de puentes nucleoplásmicos fueron significativamente mayores en los expuestos que en los no expuestos: p= 0.042 y p= 0.046, respectivamente, Razón de verosimilitud exacta). Fueron halladas diferencias significativas en la interacción de CYP2E1 (c1c1) y la exposición ocupacional a solventes, con mayores frecuencias de micronúcleos (p= 0.013) y de células micronucleadas (p= 0.015). Conclusiones: Este estudio reafirma que los trabajadores expuestos a solventes orgánicos con polimorfismos de CYP2E1, específicamente con genotipo c1c1, tienen mayor probabilidad de presentar mutaciones en las células somáticas, condición asociada con una mayor susceptibilidad a enfermedades como el cáncer

Increased frequency of micronuclei in the lymphocytes of patients chronically infected with hepatitis B or hepatitis C virus

In this study, we analysed the frequency of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) and evaluated mutagen-induced sensitivity in the lymphocytes of patients chronically infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). In total, 49 patients with chronic viral hepatitis (28 HBV-infected and 21 HCV-infected patients) and 33 healthy, non-infected blood donor controls were investigated. The frequencies (‰) of MN, NPBs and NBUDs in the controls were 4.41 ± 2.15, 1.15 ± 0.97 and 2.98 ± 1.31, respectively. The frequencies of MN and NPBs were significantly increased (p < 0.0001) in the patient group (7.01 ± 3.23 and 2.76 ± 2.08, respectively) compared with the control group. When considered separately, the HBV-infected patients (7.18 ± 3.57) and HCV-infected patients (3.27 ± 2.40) each had greater numbers of MN than did the controls (p < 0.0001). The HCV-infected patients displayed high numbers of NPBs (2.09 ± 1.33) and NBUDs (4.38 ± 3.28), but only the HBV-infected patients exhibited a significant difference (NPBs = 3.27 ± 2.40, p < 0.0001 and NBUDs = 4.71 ± 2.79, p = 0.03) in comparison with the controls. Similar results were obtained for males, but not for females, when all patients or the HBV-infected group was compared with the controls. The lymphocytes of the infected patients did not exhibit sensitivity to mutagen in comparison with the lymphocytes of the controls (p = 0.06). These results showed that the lymphocytes of patients who were chronically infected with HBV or HCV presented greater chromosomal instability.

Mayor frecuencia de aberraciones cromosómicas en linfocitos expuestos o no a mitomicina C, de mujeres posmenopáusicas obesas en comparación con mujeres no obesas del departamento del Cauca, Colombia / High frequency of chromosome aberrations observed in lymphocytes in postmenopausal obese women

Introducción. Los estudios epidemiológicos indican que la obesidad está asociada en el 25 al 30 % con varios tipos de cáncer. Objetivo. Evaluar la frecuencia de aberraciones cromosómicas en linfocitos de mujeres posmenopáusicas obesas y no obesas, mediante la prueba de reto celular (challenge assay) como biomarcador de inestabilidad genómica. Materiales y métodos. Cuarenta mujeres posmenopáusicas fueron incluidas en el estudio (20 obesas y 20 no obesas). Los grupos fueron pareados según edad (± 5 años) y procedencia. Después de la firma voluntaria del consentimiento informado, las mujeres fueron entrevistadas y se les tomó una muestra de 5 ml de sangre periférica. Se establecieron cultivos de linfocitos con tratamiento con mitomicina C y sin él (prueba de reto celular) y, posteriormente, se registró la frecuencia de aberraciones cromosómicas para cada grupo y tratamiento. Resultados. En general, las mujeres obesas presentaron una mayor frecuencia de aberraciones cromosómicas en comparación con las no obesas. Después de exponer los cultivos celulares a mitomicina C, las mujeres obesas presentaron un incremento en el número de aberraciones cromosómicas totales en comparación con las no obesas (3,74±0,63 Vs. 2,70±0,61; p=0,001). Conclusiones. La mayor frecuencia de aberraciones cromosómicas en los linfocitos de mujeres posmenopáusicas obesas que en no obesas, sugiere diferencias en la capacidad de reparación del ADN, lo cual podría explicar la asociación entre la inestabilidad genómica y la mayor incidencia de cáncer en esta población.

Introduction. Epidemiological studies indicate that obesity is associated with an increased risk of 20-25% with several types of cancer. Objective. The frequency of chromosome aberrations was evaluated in lymphocytes from postmenopausal obese and non-obese women. Materials and methods. Twenty obese and 20 non-obese women, all post-menopause, were recruited. The groups were matched according to age (± 5 years) and place of origin. After signing the consent form, women were interviewed using a structured questionnaire, and a blood sample (5 ml) was drawn into vacutainer tubes. From each sample, lymphocyte cell cultures were established with and without mitomycin C (challenge assay). Afterwards, the frequency of chromosome aberrations were recorded for each group and treatment. Data were analyzed using the statistical program SPSS, v. 14.0. Results. Obese women had a higher frequency of chromosome aberrations when compared with non-obese women. After exposing the cell cultures to mitomycin C, obese women presented an increase in the number of total chromosome aberrations in comparison to non-obese women (3.7± 0.6 vs. 2.70±0.6; p=0.001). Conclusions. The higher frequency of chromosome aberrations in lymphocytes from postmenopausal obese women compared to non-obese women suggested differences in the DNA repair capacity. This may indicate an association between genomic instability and the higher incidence of cancer in this population.

Interacciones genotóxicas de mutágenos en mezclas binarias mediante ensayo cometa alcalino en linfocitos humanos / Interaction of mutagens in binary mixtures using the alkaline comet assay in human lymphocytes

Introducción. Los mutágenos contenidos en mezclas complejas presentan interacciones de sinergismo, aditivas o antagónicas. Se han desarrollado enfoques experimentales que permitan dilucidar el responsable de las interacciones en la mezcla. Objetivo. Desarrollar un diseño experimental para comprender los procesos que se llevan a cabo entre los compuestos presentes en las mezclas complejas. Materiales y métodos. Se expusieron linfocitos humanos a mezclas binarias de mutágenos B[a]P, DMBA, Trp-P-1 y MX durante una hora, con activación metabólica y sin ella. La viabilidad se evaluó con azul de tripano y, la genotoxicidad, con cometa alcalino. Resultados. Ningún hidrocarburo tuvo efecto con furanona. Con S9 y sin él, se observó que se presentaban interacciones tóxicas entre hidrocarburos. Se observó sinergismo sin S9 entre B[a]P y Trp-P-1 y, con actividad metabólica, entre DMBA y Trp-P-1. Sin S9 se observó interacción antagónica entre Trp-P-1 y DMBA y, con S9, entre Trp-P-1 y MX y entre MX y DMBA. Se observó un incremento dependiente de la dosis en la longitud de la cola. Hubo daño genotóxico medio y aumento de las células dañadas. Para todas las mezclas se pudo determinar la concentración mínima en la que se observaban efectos adversos y solo para algunas se determinó la concentración máxima en la cual no se observaron efectos adversos. Conclusión. Se hace un aporte para comprender los procesos que ocurren cuando en una mezcla hay presentes, al menos, dos mutágenos y se valida un modelo de análisis que permite dilucidar el compuesto que tiene efecto sobre otro. También, se demostró que según el tipo de compuestos en la mezcla, se tendrá o no un umbral de riesgo.

Introduction. Mutagens contained in complex mixtures can present synergistic interactions, either additive or antagonistic. Therefore, development of experimental approaches is necessary to elucidate which is the responsible agent for the effect in the mixtures. Objective. An experimental design was developed that allowed an understanding of the processes between the compounds of complex mixtures. Materials and methods. Human lymphocytes were exposed to binary mixtures of the mutagens B[a]P, DMBA, Trp-P-1 and MX for 1 hour with or without S9. Viability was assessed with trypan blue dye and the genotoxicity by the comet assay. Results. All of the hydrocarbon showed an effect with furanone. With and without S9, the most toxic interactions were observed between hydrocarbons. Synergistic interaction was observed without S9 between B [a] P and Trp-P-1 and between DMBA and Trp-P-1 with metabolic activity. Without S9 antagonistic interaction was observed only between Trp-P-1+DMBA, and with S9 between Trp-P-1+MX and MX+DMBA. It observed an increase dose dependent in tail length. Half the cultures showed genotoxic damage and increased cell damage. For each mixture, minimum concentrations were determined at which adverse effects are observed; for some only the maximum concentration was determined at which no adverse effects are observed. Conclusion. The processes between mutagens present in a mixture have become better understood, and the results validated an analytical model that determined which component had an effect on another. The results also showed that the type of compounds in the mixture determined whether or not a risk threshold was present.

Micronucleated lymphocytes in parents of Down syndrome children

Down syndrome (DS) is the most common disease due to an autosomal aneuploidy in live born children and also the major known genetic cause of mental retardation. The risk of a DS pregnancy increases substantially with increasing maternal age. However, several women aged less than 35 years at conception have a child with DS. The micronucleus (MN) assay can identify chromosome breakage or chromosome malsegregation and is an ideal biomarker to investigate genomic instability. The aim of the present study was to determine the frequency of peripheral lymphocytes with MN in the parents of DS individuals. The subjects were 17 couples, 1 father and 9 mothers, and 24 couples who had at least one healthy child formed the control group. For each individual we evaluated the frequency of binucleated micronucleated lymphocytes (BNMN%) as number of binucleated lymphocytes containing one or more MN per 1000 binucleated cells. The mean age of DS parents and controls was 32.6 and 29.8 years, respectively. The frequency of MN in DS parents was significantly higher compared to controls. The higher frequency of MN in DS parents suggests a higher predisposition of DS parents to aneuploidy events in this sample.

Genotoxicidad por exposición a cigarrillos en fumadores jóvenes en Colombia / Genotoxicity from exposure to cigarettes in young smokers in Colombia

OBJETIVO: Evaluar la frecuencia de aberraciones cromosómicas (AC) en los linfocitos de sangre periférica de jóvenes fumadores de cigarrillos de la ciudad de Popayán, Colombia. MÉTODOS: En este estudio citogenético de casos y testigos participaron 32 jóvenes fumadores de cigarrillos y 32 jóvenes no fumadores. Todos se encontraban entre los 19 y 29 años de edad y ninguno consumía drogas psicoactivas, padecía de enfermedades crónicas o infecciosas o había estado expuesto a quimioterapia, radioterapia o a agentes químicos en el ámbito ocupacional. Se aplicó una encuesta a fin de obtener información demográfica, ocupacional (tipo de empleo, tipo y tiempo de exposición a agentes químicos), estilo de vida (consumo de bebidas alcohólicas y de drogas psicoactivas) y hábitos tabáquicos (fumador actual o previo, número de cigarrillos que fumaba diariamente, tiempo que llevaba fumando y tipo de cigarrillos que fumaba). Se parearon los casos con los testigos según la edad (± 5 años) y el sexo. El estudio microscópico de las AC a partir de cultivos de linfocitos se realizó bajo el microscopio óptico con un aumento de 100X. Se analizaron 100 células en metafase completa (2n= 46 cromosomas) por persona y se contaron las AC estructurales (quiebres cromatídicos y cromosómicos) y numéricas (cambio en el número de cromosomas). Se ajustó la frecuencia de AC en función del consumo de alcohol mediante un modelo lineal unifactorial. RESULTADOS: La frecuencia de AC totales fue significativamente mayor en los jóvenes fumadores de cigarrillos (6,02 ± 0,52) que en los que no fumaban (3,04 ± 0,50) y el mayor número de AC (7,77 ± 0,88) se encontró en los que fumaban más de 3,0 años-cajetilla. Además, se observó una relación entre dosis y efecto, demostrada por el aumento de la frecuencia de AC al aumentar la intensidad del consumo (r² = 0,2257). CONCLUSION: Se confirmó la presencia de una asociación entre el consumo de cigarrillos y las AC en jóvenes que fumaban poco. Estos resultados se deben tomar en cuenta para formular las políticas nacionales de prevención del tabaquismo y para evaluar las consecuencias del hábito de fumar, tanto desde el punto de vista social, económico y ambiental, como desde el punto de vista de la salud de las generaciones futuras.

Aspectos morfológicos y citoquímicos de las células sanguíneas de salminus maxillosus: characiformes characidae / Morphological and cytochemistry observation in blood cells of salminus maxillosus: characiformes characidae

Las características morfológicas de sangre periférica del pez Salminus maxillosus fueron descritas usando microscopía de luz. Para demostrar el comportamiento citoquímico de las células sanguíneas del pez en estudio, fueron aplicados métodos específicos para la detección de cuatro tipos básicos de componentes macromoleculares, de naturaleza química diferente: carbohidratos, lípidos. proteínas enzimáticas y estructurales. Fueron observados 6 tipos de células: eritrocitos, trombocitos, monocitos, linfocitos, neutrófilos de los tipos I y II y eosinófilos. Los trombocitos y los neutrófilos de los tipos I y II presentaron glucógeno en el citoplasma. Los neutrófilos del tipo II presentan gránulos sudanófilos y mielloperoxidasa. Además presentan, reacción difusa intensa para proteínas en el citoplasma. Los eosinófilos muestran reacción intensa en sus gránulos

Monitoring of molecular ans cytogenetic damage in lymphocytes from three persons with polycystic kidney disease

Background. Much interest has been generated in the studies that would help to under stand whether is a causal association between disease and various types of molecular or cytogenetic damage detected in human cells. Materials and Methods. The aims of this study were to elicit the possible association between DNA and cytogenetic damage induced in lymphocytes of three members of a family with autosomal dominant polycystic kidney disease (ADPKD). Ther predictability to develop cancer or to sensitive response to enviromental exposure of the young girl at the age of 19, her brother (9 years old) and a maternal aunt at the age of 41 were sought. Cytogenetic studies, analysis of DNA damage by single cell gel electrophoresis assay (SCGE known as a Comet assay), and analysis of p21ras protein level in blood plasma were carried out on their lymphocytes. Results. The analysis for presence of chromosome aberrations in the first mitosis and sister chromatid exchanges in the second mitosis revealed elevated levels of cytogenetic biomarkers when compared to the mean values observed in the reference group in environmental biological monitoring studies. Results of sister chromatid exchanges (SCE) and percent of cells with elevated number of exchanges (high frequency cells) that were significantly higher in two probands had demonstrated susceptibility to or possibility of enviromental exposure (pesticides, smoking). The results of this study show that the lymphocytes of two persons revealed increased sensitivity to 0.5 Gy dose of gamma radiation expressed in the increased, atthough statistically insignificant, damage detected on the molecular level after cell irradiation. Conclusions. The latter might be associated with a specific aberration present in the cells of these persons. But final conclusions can be arrived at when an application of FISH technique is completed

Inflammatory response of the spinal cord to multiple episodes of blood-brain barrier disruption and toxic demyelination in Wistar rats

Multiple episodes of blood-brain barrier disruption were induced by sequential intraspinal injections of ethidium bromide. In addition to the barrier disruption, there was toxic demyelination and exposure of myelin components to the immune system. Twenty-seven 3-month-old Wistar rats received 2, 3 or 4 injections of 1 mul of either 0.1 percent ethidium bromide in normal saline (19 rats) or 0.9 percent saline (8 rats) at different levels of the spinal cord. The time intervals between the injections ranged from 28 to 42 days. Ten days after the last injection, all rats were perfused with 2.5 percent glutaraldehyde. The spinal sections were evaluated macroscopically and by light and transmission electron microscopy. All the lesions demonstrated a mononuclear phagocytic infiltrate apparently removing myelin. Lymphocytes were not conspicuos and were found in only 34 percent of the lesions. No perivascular cuffings were detected. In older lesions (38 days and older) they were found only within Virchow-Robin spaces. This result suggests that multiple blood-brain barrier disruptions with demyelination and exposure of myelin components to the immune system were not sufficient to induce an immune-mediated reaction in the central nervous system.

Activity satellite association and polymorphismo of Ag stained nucleolus organizer regions (Ag+ NORs) in lymphocytes from women with cervical uterine cancer

Thirty five female patients with different stages of neoplastic lesions: cervical intraepithelial neoplasia (CIN) or dysplasia (CIN I and CIN II), in situ carcinoma (CIS), and adenocarcinoma, and 27 healthy women (controls) wee studied to determine the activity, satellite association, and jpolymorphism of Ag stained nucleolus organizer regions (Ag+NORs) in acrocentric chromosomes in metaphases obtained from peripheral blood lymphocytes. For each person, 25 to 50 metaphases stained with ammoniacal silver technique were scored. The average number of Ag+ NORs was higher in women with adenocarcinoma (7.66 ñ 0.72) than in controls (6.65 ñ 0.74). Non-associated chromosomes showing Ag+ NORs were found more frequently in patients (5.85 ñ 0.88) than in controls (4.81 ñ 0.67). Patients aged 30-39 and 60 or more had an increase of Ag+ NORs (7.99 ñ 1.04, and 7.81 ñ0.71) with respect to their controls (6.36 ñ 0.052 and 6.17 ñ 0.88), but the frequency of satellite association showed lower values in 50 -59 year-old patients (0.75 ñ 0.08) than in controls (1.02 ñ 0.19). The most frequent association in patients was the large type (patients = 38.96 perecent, controls 30.49 ). The partial association showed higher values (6.49 percent) than controls (2.44 percent). Otherwise, the spherical association was more frequent for controls (37.80 percent) than for patients (28.57 percent). All these differences were statistically significant (p<0.05). The frequency of Ag+ NORs and the type of polymorphism of satellite association could be related to the neoplastic process, while the frequency of satellite association and of polymorphism of Ag+ NORs seems to be irrelevant

C-anaphases (Common Variant) are unrelated to colchicine and phytohemagglutinin

We wvaluated the effect of different concentrations of colchicine (0.0, 0.1, 0.3, 0.5 µg/ml) and phytohemagglutinin (PHA) (0.10, 0.15, 0.20 µg/ml) on the rate of C-anaphases in lymphocyte cultures from five healthy individuals with the common variant of C-anaphases. For each of the 12 possible combinations, two subjects were randomly tested. The frequency of these variant figures was <3 percent; a single culture (out of six with the colchicine concentration of 0.1 µg/ml) lacked C-anaphases. Multiple variance and Student's t tests revealed, as the only significant difference, a decrease with the colchicine concnetration of 0.3 µg/ml compared with the cultures without colchicie (p<0.05), which exhibited the greatest ratio of C-anaphases. The PHA had no influence on the frequency of C-anaphases. We conclude that the common variant of C-anaphases is unrelated to the colchicine and PHA concentrations tested; moreover, our data confirm the occurrence of such a mitotic variant in colchicine-free cultures

Cytogenetic analysis of malignant B-cells from iranian patients with chronic lymphocytic leukemia

Lymphocytes of 37 Iranian patients with B-cell chronic lymphocytic leukemia were stimulated with different mitogens i.e., phorbol myristate acetate [PMA], pokweed mitogen and Staphylococcus aureus Cowan I. Adequate metaphases were obtained in 23 subjects following PMA stimulation. Cytogenetic analysis of G-banded mitosis showed both numerical and structural abnormalities. The most frequent abnormality observed in this study involved chromosome 21 [-21 in four cases and +21 in three cases]. Trisomy 12 and 15 as well as structural abnormalities and other alterations related to chromosomes 2, 3, 6, 7, 10, 12, 18 and 19 were also observed. The high frequency of numerical abnormalities involving chromosome 21 found in this study may be considered as a characteristic feature of B-CLL in Iran

Trifluoperazine reduces the expression of CD69 in phytohemagglutinin-activated lymphocytes

Trifluoperazine (TFP) is a phenothiazine capable of inhibiting lymphocyte proliferation as well as natural killer cells (NK) and lymphokine-activated killer cells (LAK) cytotoxic activity. CD69 is a surface molecule induced by various mechanisms of cellular activation. In the present work the modulation of CD69 expression by TFP was investigated on PHA-stimulated peripheral blood mononuclear cells and compared to that of CD25 (IL-2 receptor) expression. Determination of surface molecules was performed in an indirect immunofluorescence assay using anti-CD69 or anti-CD25 monoclonal antibodies, and analyzed by flow cytometry. The time course of the expression of these two molecules differed: CD69 expression was already declining at 48 h, whereas CD25 was still increasing at 72 h after stimulation. TFP (10 muM) reduced CD69 expression by 71.8 per cent at 24 h, 68.4 per cent at 48 h and 24 per cent at 72 h following activation. In contrast, the same dose of TFP did not significantly affect CD25 expression at 24 h but showed an inhibitory effect at later times. These results suggest that different activation pathways are involved in the expression of CD25 and CD69.

Studies on the surface properties of human lymphocytes by photon correlation spectroscopy technique.

Electrokinetic behaviour of human lymphocytes was studied by photon correlation spectroscopy technique on laser IR-spectrometer. The electrophoretic mobilities (EPMs) were measured for peripheral blood lymphocytes (PBL) and CEM-C12 T cell line in 1:1 electrolyte at 22 degrees C. Plots of mobility vs ionic strength in the range 0.001-0.1 M were compared with theoretical curves calculated from (i) the Smoluchowsky formula, (ii) the simplified form of the Dukhin-Deryaguin equation which takes into account the fact that the mobility decreases due to the relaxation effect and (iii) the equation suggested by Donath and Pastushenko, which takes into account the influence of cell glycoprotein layer (GPL) on the EPM values. It has been found that the first two equations describe the experimental data with the assumption that surface charge density (sigma) decreases and width of the hydrodynamically immobile layer (L) increases with decreasing ionic strength; the relaxation effect turns out to be insignificant for the cell charges and sizes under consideration. In agreement with these findings, the third equation is approximately consistent with experimental data on the condition that GPL is allowed to expand with decreasing ionic strength, with simultaneous decrease of its full charge density (sigma(f)). The results are compared with relevant evidence for erythrocytes. The possible applications of the inferences arrived at in electrophoretic studies of cell behaviour are also discussed.

Morfometria do intestino delgado em crianças com diarréia por Escherichia coli enteropatogênica clássica e enteropatia ambiental assintomática / Morphometrics of the small bowel in children with diarrhea due to classical enteropathogenic Escherichia coli and to environmental asymptomatic enteropathy

Infecçäo entérica por Escherichia coli enteropatogênica clássica (EPEC) pode causar diferentes graus de alteraçöes das vilosidades do intestino delgado.OBJETIVOS. Este estudo teve por objetivo: 1) avaliar as alteraçöes morfológicas da mucosa intestinal na diarréia aguda por EPEC, por meio da morfometria linear, e compará-la a um grupo controle; 2) comparar o número de LIE encontrado na diarréia aguda e/ou persistente por EPEC com aqueles encontrados no grupo controle; 3) pesquisar a presença de E. coli aderida à mucosa do intestinodelgado naquelas crianças que apresentaram diarréia com coprocultura positiva para EPEC. PACIENTES E MÉTODOS. Foram analisados 30 biópsias da mucosa do intestino delgado de crianças com diarréia aguda e/ou persistente, com coprocultura positiva para EPEC e 16 biópsias obtidas da mucosa do intestino delgado de crianças portadoras de enteropatia ambiental assintomática, que constituíram nosso grupo controle. Foram realizadas as seguintes análises morfométricas: RESULTADOS: Espessura total mucosa µ EPEC=279,6 EAA=445,1 p<0,001; Altura vilosidade µ EPEC 134,3 EAA 248,0 p<0,001; Extensäo da zona críptica µ EPEC 145,2 EAA 197,1 p<0,02; linfócitos intra-epiteliais EPEC 11,6 EAA 15,5 p<0,005. CONCLUSÄO. Presença de bactéria gram-negativa, portanto, provavelmente, EPEC, foi constatada em três dos 30 pacientes com diarréia, apresentando coprocultura positiva para EPEC. As alteraçöes morfométricas ocorrem, principalmente, às custas da diminuiçäo das visolidades intestinais.

Efecto citogenético del ozono en cultivo de linfocitos humanos / Cytogenetic effect of ozono on human cultures lymphocyte

El ozono es un poderoso oxidante atmosférico, formado en las reacciones de smog fotoquímico entre hidrocarburos volátiles y óxidos de nitrógeno (NOx), cuya acción biológica se manifiesta en la destrucción oxidante de biomóleculas, razón por la cual se ha considerado importante conocer sus efectos en la salud. En vista de que los niveles de ozono presentes en la ciudad de México son elevados y, debido a que la información sobre su efecto a nivel genético es escasa y contradictoria, en este trabajo se evalúa su acción citogenética mediante el análisis de intercambio de cromátides hermanas (ICH) en cultivo de linfocitos humanos. Se realizó burbujeo directo de ozono sobre cultivo de linfocitos durante 30 min a concentraciones 0.2, 0.3 y 0.4 ppm, las mediciones fueron hechas con un monitor Dasibi 1008-AH. Los resultados mostraron que a estas concentraciones y tiempo de tratamiento, no se elevaron significativamente las frecuencias del ICH

Sitios frágiles en linfocitos de pacientes con carcinoma canalicular infiltrante de mama / Fragile sites in lymphocytes of patients with breast canalicular infiltrating carcinoma

Los sitios frágiles son puntos específicos en los cromosomas que se manifiestan como brechas y roturas. Algunas de ellas se pueden presentar en un individuo normal y se consideran como alteraciones constitutivas que se expresan en cualquier célula del individuo. La búsqueda de sitios frágiles en sujetos con cáncer de mama puede proveer información en cuanto a una predisposición a este tipo de neoplasia, ya que se ha propuesto que los sitios frágiles podrían estar relacionados con algunos de los rearreglos cromosómicos estructurales que se presentan en las células neoplásicas. Con esto en mente se determinó la frecuencia de sitios frágiles en linfocitos de 15 pacientes con carcinoma canicular infiltrante de mama y de 15 individuos controles y se relacionó con algunos parámetros clínicos de las pacientes. No existió diferencia significativa en la frecuencia y tipo de sitios frágiles en pacientes con cáncer de mama e individuos controles. Sin embargo, se encontró diferencia estadísticamente significativa entre la frecuencia de aberraciones cromosómicas y la presencia en el tumor de receptores para progesterona (p = 0.4); se desconoce la relevancia biológica de este fenómeno. Se concluye que los sitios frágiles cromosómicos no están relacionados con una predisposición a carcinoma canicular infiltrante de mama

Ensayo de la proliferación celular en cultivo de linfocitos de cerdo / Assay kinetics cell proliferations lymphocytes from pigs

Se reporta el cultivo de linfocitos de sangre periférica completa de cerdos sanos e infectados, para evaluar la cinética de proliferación celular; 0.5 ml de sangre fue cultivada en 6.0 ml de RPMI-11640 suplementado, en presencia de fitohemaglutinina y 5-BrdU, a 37§C. Al cabo de 48 horas de incubación se cosecharon y fueron teñidos de acuerdo a la técnica de fluorescencia más Giemsa, obteniéndose así células en diferentes etapas de diferenciación, identificándolas en primera, segunda y tercera división. La actividad proliferativa se midió bajo dos parámetros: índice mitótico e índice de replicación. Los resultados son reproducibles y se pueden diferenciar los efectos citotóxicos de los citostáticos sobre los linfocitos del huésped

Relative ranking of culture media based on proliferation kinetics and spontaneous chromosomal aberrations in PHA-responsive human peripheral blood lymphocytes.

Proliferation kinetics and spontaneous yield of chromosomal aberrations phytohemagglutinin (PHA)-responsive peripheral blood lymphocytes were studied from blood samples collected from 45 individuals in 4 different synthetic media. Except for a significant difference for Eagle's MEM and RPMI 1640, the other media did not show difference for the yield of chromatid or chromosome type of aberrations. Differences were however noticed in the proliferation kinetics (mitotic and proliferative rate indices) of cells among the media used. The study indicated that (i) the intrinsic properties of media which influence proliferation rate and yield of chromosomal aberrations are independent of each other as higher proportion of first division cells do not correspond with higher frequency of chromosomal aberrations, (ii) the amount of free-radical scavengers present in the medium, apart from the genetic make-up of the individuals, may contribute to the spontaneous yield of chromosomal aberrations and (iii) RPMI 1640 medium, which showed higher transformation and faster cycling rate for the lymphocytes, may be considered as medium of choice for analysing two main cytogenetic end-points, chromosomal aberrations and sister chromatid exchanges (SCEs).