Tartrazina induce genotoxicidad en linfocitos de BALB/c Mus musculus / Tartrazine induces genotoxicity in BALB/c Mus musculus lymphocytes

RESUMEN Objetivos. Determinar el efecto genotóxico de la tartrazina en linfocitos de sangre periférica de Mus musculus BALB/c. Materiales y métodos. Se realizó un estudio experimental, a través de cinco grupos, con cinco ratones en cada uno. Se les registró el peso durante 17 semanas y, en la semana 15 se les administró suero fisiológico (control negativo), dicromato de potasio 25 mg/kg de peso corporal (pc) (control positivo) y tartrazina a dosis de 0,75 mg/kg pc, 7,5 mg/kg pc y 75 mg/kg pc, durante siete días, a excepción del control positivo que fue en dosis única. Luego, cada 24 h se obtuvo una muestra de sangre periférica de la cola y se realizó el frotis, secado y coloración. Posteriormente, se realizó el conteo de 1000 linfocitos por muestra de cada ratón, en todos los tratamientos. Resultados. Los tres tratamientos con tartrazina no causaron diferencias significativas en el peso de ratones a la semana 15, pero sí produjeron diferencias significativas en la frecuencia de linfocitos micronucleados, siendo el tratamiento con tartrazina de 75 mg/kg pc el de mayor efecto genotóxico, induciendo un promedio de 1,63 ± 0,08 linfocitos micronucleados, comparado con el control positivo que generó un promedio de 1,42 ± 0,08 linfocitos micronucleados. Conclusiones. La tartrazina produjo un efecto genotóxico, incrementando el número de linfocitos micronucleados, a dosis de 0,75; 7,5 y 75 mg/kg pc y no afecta el peso corporal durante siete días de administración en M. musculus BALB/c.

ABSTRACT Objectives. To determine the genotoxic effect of tartrazine on peripheral blood lymphocytes of BALB/c Mus musculus. Materials and methods. An experimental study was carried out using five groups, with five mice in each group. Their weight was registered for 17 weeks, and at week 15 they were administered physiological saline solution (negative control), potassium dichromate at 25 mg/kg body weight (bw) (positive control) and tartrazine at doses of 0.75 mg/kg bw, 7.5 mg/kg bw and 75 mg/kg bw, for seven days, with the exception of the positive control which was a single dose. Then, every 24 hours, a peripheral blood sample was obtained from the tail, which was then smeared, dried and stained. Subsequently, 1000 lymphocytes were counted for each sample from each mouse, for all treatment groups. Results. The three tartrazine treatments did not cause significant differences in the weight of mice at week 15, but did produce significant differences in the frequency of micronucleated lymphocytes, with the 75 mg/kg bw tartrazine treatment having the greatest genotoxic effect, inducing an average of 1.63 ± 0.08 micronucleated lymphocytes, compared to the positive control which obtained an average of 1.42 ± 0.08 micronucleated lymphocytes. Conclusions. Tartrazine produced a genotoxic effect, increasing the number of micronucleated lymphocytes, at doses of 0.75; 7.5 and 75 mg/kg bw and did not affect body weight during seven days of administration to BALB/c M. musculus.

The correlation between micronuclei count and smoking behavior: a hospital-based study / Correlación entre recuento de micronúcleos y hábito tabáquico: un estudio hospitalario

Background: Micronucleus is a microscopically visible cyto-plasmic chromatin mass in the extranuclear vicinity, originating from aberrant mitosis, which consists of eccentric chromosomes that have failed to reach spindle poles during mitosis. The present study was designed to evaluate and compare cytogenetic changes in the buccal mucosa of smokers and non-smokers based on the occurrence of micronuclei. The study aimed to determine the correlation between the micronuclei count and the frequency and duration of smoking habit. Materials and Methods: Two groups (smokers and non-smokers) of 34 individuals each were examined. Cytological buccal smears were taken from participants using a moistened wooden spatula and stained with standard Papanicolaou stain. Presence of micronuclei was assessed at 40X magnification using a light microscope and a count per 500 cells was determined. The results of the study were analyzed statistically using Mann-Whitney U test, Spearman's rank correlation coefficient and Student t-test. Result: Smears from smokers showed a significant increase in the total number of micronuclei per 500 cell count compared to non-smokers. There was a strong positive correlation between the occurrence of micronuclei and the frequency and duration of smoking. A age-related increase in older age groups was also observed. Conclusion: The study reveals a strong positive correlation between the occurrence of micronuclei and the frequency and duration of smoking. This observation is vital in the utilization of the micronuclei detection in smears as a prognostic, educational and interventional tool in the management of patients with smoking habits.

Antecedentes: El micronúcleo es una masa de cromatina citoplasmática microscópicamente visible en el área extranuclear, que se origina a partir de la mitosis aberrante, y que consiste en cromosomas excéntricos que no han podido alcanzar los polos del huso durante la mitosis. El presente estudio fue diseñado para evaluar y comparar los cambios citogenéticos en la mucosa bucal de fumadores y no fumadores en función de la aparición de micronúcleos. El estudio tuvo como objetivo determinar la correlación entre el recuento de micronúcleos y la frecuencia y duración del hábito de fumar. Materiales and Métodos: Se examinaron dos grupos (fumadores y no fumadores) de 34 individuos cada uno. Se tomaron frotis bucales citológicos de todos los participantes con una espátula de madera humedecida y se tiñeron con la tinción estándar de Papanicolaou. La presencia de micronúcleos se evaluó al microscopio óptico con un aumento de 40X y se determinó un recuento por 500 células. Los resultados del estudio se analizaron estadísticamente utilizando la prueba U de Mann-Whitney, el coeficiente de correlación de rango de Spearman y la prueba t de Student. Resultados: Los frotis de fumadores mostraron un aumento significativo en el número total de micronúcleos por 500 células en comparación con los no fumadores. Hubo una fuerte correlación positiva entre la aparición de micronúcleos y la frecuencia y duración del tabaquismo. También se observó un aumento relacionado con la edad en los grupos de mayor edad. Conclusión: el estudio revela una fuerte correlación positiva entre la aparición de micronúcleos y la frecuencia y duración del tabaquismo. Esta observación es vital en la utilización de la detección de micronúcleos en frotis como una herramienta pronostica, educativa e intervencionista en el manejo de pacientes con hábitos de fumar.

Citometría de flujo en reticulocitos de sangre periférica como indicador de inestabilidad cromosómica en pacientes con gliomas de alto grado / Flow cytometry in peripheral blood reticulocytes as a marker of chromosome instability in highgrade glioma patients

Resumen Introducción. La cuantificación de la inestabilidad cromosómica es un parámetro importante para evaluar la genotoxicidad y la radiosensibilidad. Las técnicas convencionales requieren cultivos celulares o laboriosos análisis microscópicos de cromosomas o núcleos. La citometría de flujo en reticulocitos ha surgido como una alternativa para los estudios in vivo, ya que reduce los tiempos de análisis e incrementa hasta en 20 veces el número de células analizables. Objetivos. Estandarizar los parámetros de citometría de flujo requeridos para seleccionar y cuantificar reticulocitos micronucleados (RET-MN) a partir de muestras de sangre periférica, y cuantificar la frecuencia de esta subpoblación anormal como medida de inestabilidad citogenética en sendas poblaciones de voluntarios sanos (n=25) y pacientes (n=25) recién diagnosticados con gliomas de alto grado antes de iniciar el tratamiento. Materiales y métodos. Las células sanguíneas se marcaron con anti-CD71-PE para reticulocitos, anti- CD61-FITC para la exclusión de plaquetas y yoduro de propidio para detectar el ADN en reticulocitos. La fracción celular MN-RETCD71+ se seleccionó y se cuantificó con un citómetro de flujo automático. Resultados. Se describió detalladamente la estandarización de los parámetros citométricos, con énfasis en la selección y la cuantificación de la subpoblación celular MN-RETCD71+. Se establecieron los niveles basales de MN-RETCD71+ en la población de control y en los pacientes se encontró un incremento de 5,2 veces antes de iniciar el tratamiento (p<0,05). Conclusión. Los resultados evidenciaron la utilidad de la citometría de flujo acoplada a la marcación de las células RETCD71+ como método eficiente para cuantificar la inestabilidad cromosómica in vivo. Se sugieren posibles razones del incremento de micronúcleos en células RETCD71+ de pacientes con gliomas.

Abstract Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti- CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.

Avaliação de danos genotóxicos e citotóxicos em células da mucosa bucal de soldadores nas cidades de Cubatão e Santos, São Paulo / Evaluation of genotoxic and cytotoxic effects in buccal mucosa cells of welders in the cities of Cubatão and Santos, state of São Paulo, Brazil

Contexto: Estima-se que no mundo existam, aproximadamente, 5 milhões de trabalhadores expostos ocupacionalmente à fumaça de soldagem. Níquel e Cromo são metais que podem ocasionar danos ao material genético, e soldadores, por força do ofício, são rotineiramente expostos a eles. Objetivo: O objetivo do presente estudo foi investigar a frequência de danos citotóxicos e genotóxicos em células da mucosa bucal de um grupo de soldadores. Métodos: Um total de 44 indivíduos, distribuídos em 2 grupos ­ soldadores e não soldadores ­, foi comparado utilizando a técnica do ensaio do micronúcleo e morte celular (picnose, cariorrexe e cariólise) em células da mucosa oral de trabalhadores de soldagem. As células examinadas foram coradas com Feulgen/Fast-green. Resultado: Os soldadores apresentaram maior frequência (p<0,05) de alterações indicativas de citotoxicidade quando comparados ao grupo de indivíduos não expostos a fumos metálicos. Conclusão: Os resultados deste estudo preliminar sugerem que soldadores apresentam maior frequência de danos citotóxicos e morte celular em células da mucosa bucal que trabalhadores não expostos.

Context: It is estimated that approximately 5 million workers are occupationally exposed to welding fumes worldwide. Nickel and Chromium are genotoxic metals found in welding fumes and thus welders are exposed to these metals at the working place. Objective: The objective of this study was to investigate the frequency of cytotoxic and genetic damage in cells harvested from the oral mucosa of welders and also from a group of workers not exposed to metallic fumes. Methods: A total of 44 individuals, divided into 2 groups ­ welders and not-welders ­ were compared using the micronucleus assay technique and cell death (pycnosis, karyorrexis and karyolysis) in buccal mucosa cells of welding workers. The cells examined were staining with Feulgen/Fast-green. Results: Welders presented higher frequency (p<0.05) of cytotoxicity than the group of volunteers who were not exposed to metallic fumes. Conclusion: The results from this preliminary study suggest that welders may have a higher frequency of cytotoxic damage in buccal mucosa cells than non-welding workers.

Micronuclei and nuclear anomalies in Mexico's indigenous population / Micronúcleos y anormalidades nucleares en población indígena de México

Abstract: Objective: To determine the number of micronuclei and nuclear anomalies in Mexico's indigenous population. Materials and methods: One hundred twenty indigenous individuals were evaluated, including thirty from the ethnicities Cora, Huichol, Tarahumara and Tepehuano. The number of micronuclei (MN) and any nuclear abnormality (NA) in oral mucosa cells, including cells with nuclear buds, binucleated cells, cells with karyolysis, karyorrhetic, condensed chromatin and pyknotic cells were determined for each participant. Results: Tepehuano and Tarahumaras showed the greatest damage to DNA. The Tepehuano group presented the highest number of MN and NA, this being a significant difference (p < 0.05) compared with the rest of the studied groups. This group also presented the highest herbicide exposure (46.7%). In relation to the smoking and drinking habits, these were more frequent in the Tarahumara group (33.3 and 50% respectively). Conclusion: The ethnic diversity, habits and customs may influence the DNA nuclear integrity in the Amerindian groups.

Resumen: Objetivo: Determinar el número de micronúcleos y anomalías nucleares en la población indígena de México. Material y métodos: Se evaluó a ciento veinte indígenas, incluyendo treinta individuos de las etnias cora, huichol, tarahumara y tepehuana. A cada participante se le determinó el número de micronúcleos (MN) y de alguna anomalía nuclear (AN) en células de mucosa bucal, incluyendo células con brotes nucleares, binucleadas, cariolisis, cariorrexis, cromatina condensada y picnóticas. Resultados: Los tepehuanos y tarahumaras mostraron el mayor daño al ADN. El grupo tepehuano presentó el mayor número de MN y AN, con una diferencia significativa (p < 0.05) en comparación con el resto de los grupos estudiados; este grupo presentó también la mayor exposición a herbicidas (46.7%). En relación con los hábitos de fumar y beber, se presentaron con mayor frecuencia en el grupo tarahumara (33.3 y 50%, respectivamente). Conclusión. La diversidad étnica, hábitos y costumbres pueden influir la integridad del ADN en los grupos amerindios.

Antiproliferative and genotoxic effects of nature identical and artificial synthetic food additives of aroma and flavor / Efeito antiproliferativo e genotóxico de aditivos alimentares de aroma e sabor sintéticos, dos tipos idêntico ao natural e artificial

Abstract This study aimed to analyze the antiproliferative and genotoxic potential of synthetic food flavorings, nature identical passion fruit and artificial vanilla. This assessment used root meristem cells of Allium cepa L., in exposure times of 24 and 48 hours and using doses of 0.2; 0.4 and 0.6 mL. Roots were fixed in Carnoy’s solution, hydrolyzed in hydrochloric acid, stained with acetic orcein and analyzed with optical microscope at 400× magnification, 5,000 cells for each treatment. For data analysis, it was used Chi-square test at 5%. Doses of 0.2 mL at ET 48 h; 0.4 and 0.6 mL at ET 24 and 48 h of passion fruit flavor, and the three doses of the vanilla flavor at ET 24 and 48 h significantly reduced the cell division rate in the meristems of roots, proving to be cytotoxic. Doses of 0.2; 0.4 and 0.6 mL of the passion fruit additive, and the three doses of vanilla tested, in the two exposure times, induced mitotic spindle changes and micronuclei formation in the cells of the test organism used, proving to be genotoxic. Therefore, under the studied conditions, flavoring solutions of vanilla and passion fruit, marketed nationally and internationally, significantly altered the functioning of the cell cycle in root meristem cells of A. cepa.

Resumo Neste trabalho teve-se por objetivo analisar o potencial antiproliferativo e genotóxico de aromatizantes alimentares sintéticos, idêntico ao natural de Maracujá, e artificial de Baunilha. Esta avaliação foi realizada por meio das células meristemáticas de raízes de Allium cepa L., nos tempos de exposição de 24 e 48 horas e nas doses de 0,2; 0,4 e 0,6 ml. As raízes foram fixadas em solução de Carnoy, hidrolisadas em ácido clorídrico e coradas com orceína acética. Analisou-se, em microscópio óptico em aumento de 400×, 5.000 células por grupo tratamento, e utilizou-se o teste estatístico Qui-quadrado a 5% para análise dos dados. Verificou-se que as doses de 0,2 ml, no TE 48 h; 0,4 e 0,6 ml, nos TE 24 e 48 h, do aromatizante de Maracujá, e as três doses analisadas, nos TE 24 e 48 h, do aditivo de Baunilha reduziram significativamente o índice de divisão celular dos meristemas de raízes, mostrando-se citotóxicas. As doses 0,2; 0,4 e 0,6 ml do aditivo de Maracujá, e a de 0,6 ml do aromatizante de Baunilha, nos dois tempos de exposição considerados, induziram alterações de fuso mitótico e micronúcleos as células do organismo de prova utilizado, mostrando-se genotóxicas. Portanto, nas condições analisadas, as soluções aromatizantes de Baunilha e Maracujá, comercializadas nacional e internacionalmente, alteraram significativamente o funcionamento do ciclo celular das células meristemáticas de raízes de A. cepa.

Assessment of hematopoiesis and cytogenetics changes in interventional radiologists / 浙江大学学报·医学版

To investigate hematopoiesis and cytogenetics changes in staff of interventional radiology.A total of 121 intervention radiation workers, 245 common radiation workers and 100 medical personnel (healthy control) without exposure to radiation were enrolled in the study. The peripheral lymphocyte chromosomal aberrations and micronucleus were detected, and the result of white blood cells examination was analyzed.Compared with common radiation group and healthy control group, decreases in white blood cells count, neutrophil ratio, and increase in lymphocyte ratio were observed in intervention radiation group (all<0.05). Intervention radiation group had higher chromosome aberration rate and micronuclear rate than common radiation group and healthy control group (all<0.05). Most common chromosome aberrations were dicentric chromosome, acentric ring, fragments and minute chromosome. Abnormal rates in chromosome aberration and micronucleus rates were increased with the rise of length of service, but no statistically significant difference was observed (>0.05).Long term exposure to ionizing radiation may lead to changes in the human hematopoietic system and cause human chromosome aberration, and the severity of such injuries may be associated with the dose of ionizing radiation.

Effect of CCM3 gene defect on lead-induced cell genotoxicity in mouse embryonic fibroblasts / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of CCM3 gene defection on lead induced cell genotoxicity in mouse embryonic fibroblasts.</p><p><b>METHODS</b>C57 female mice were mated with CCM3 gene heterozygous male mice. E13.5 embryos were taken to isolate primary mouse embryonic fibroblasts. After genotyping, wild type and heterozygous cells were treated with different doses of lead acetate. Cell viability, genotoxicity and protein expression were detected by MTS assay, CB micronucleus method and Western blot, respectively.</p><p><b>RESULTS</b>Mouse embryonic fibroblasts with lead acetate treatment for 24 h, wild-type cells 100.00 µmol/L lead acetate-treated group (69.16±1.36) and the control group (100.00±2.33) compared to cells decreased by 30%, CCM3 heterozygous type cell 100.00 µmol/L lead acetate-treated group (87.16±5.50) and the control group (100.00±2.06) compared to cells decreased by 13%, the difference was statistically significant (F values were 98.59, 82.63, P<0.001). Lead acetate treatment after 48 h, wild-type cells 100.00 µmol/L lead acetate-treated group (51.99±5.62) and the control group (100.00±3.11) compared to cells decreased by 50%, heterozygous type cells 100.00 µmol/L lead acetate treatment group (66.33±4.06) and the control group (100.00±5.72) compared to cells decreased by 35%, the differences were statistically significant (F values were 82.63, 36.86, P < 0.001). The results of CBMN test showed that with increased dose, micronucleus cell rate of two genotypes showed an increasing trend, in the wild-type cells, the micronucleus cell rate (/1 000) for the control group, 29.6±2.2, 6.25 µmol/L dose group 47.3±6.6, 25 µmol/L dose group 55.5±9.1, 100.00 µmol/L dose group 66.8±3.5; heterozygous cells micronucleus cell rate (/1 000) for the control group, 35.3±5.6, 6.25 µmol/L dose of 50.0±8.3, 25.00 µmol/L dose group 57.0±8.5, 100.00 µmol/L dose group 58.8±2.1. Micronucleus cell rates (/1 000) were significant differences, in 100.00 µmol/L dose groups of two genotypes. Western blot results showed that wild-type cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.70±0.03) was 1.32 times higher than the control group (0.53±0.07), heterozygous cells CCM3 expression 100.00 µmol/L lead acetate-treated group (0.48±0.02) was 1.77 times higher than control group that of 0.27±0.04, there was statistically significant difference (F values were 14.77, 25.74, P < 0.001); wild-type cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.69±0.03) was 1.06 times higher than the control group (0.65±0.07), heterozygous cells γ-H2AX expression 100.00 µmol/L lead acetate-treated group (0.99±0.04) was 1.55 times higher than the control group CCM3 expression levels (0.64±0.06), there was statistically significant difference (wild-type cells: F = 7.08, P = 0.012, heterozygous type cell: F = 13.49, P = 0.002).</p><p><b>CONCLUSION</b>CCM3 gene may play a role in lead-induced genetic toxicity of mouse embryonic fibroblasts, CCM3 gene-lead interactions effects on mouse embryonic fibroblasts cell toxicity.</p>

Re-emergence of Chorioptes bovis (Acari: Psoroptidae) in cattle in the state of Rio Grande do Sul, Brazil / Reemergência de Chorioptes bovis (Acari: Psoroptidae) em bovinos no Estado do Rio Grande do Sul, Brasil

Here we describe an outbreak of chorioptic mange in cattle, 56 years after its first identification in Brazil. Between the months of June and July 2011, dermatitis characterized by alopecia and crusted and thickened skin at the insertion of the tail and in the ischiorectal fossa was recognized in 40 (35.7%) out of 112 Holstein cows on a farm in the northeastern mesoregion of the state of Rio Grande do Sul, Brazil. After diagnosing mange caused by Chorioptes bovis, the cows were weighed and treated with 0.5% ivermectin, as a pour-on single dose, and were separated into two groups: cows in early lactation and those in late lactation. The survival rate of C. bovis and the healing rate in the two groups of infested cows were monitored every seven days through skin scrapings. After 28 days of evaluation, the cure rate through treatment was greater among cows in early lactation (p <0.0001). The survival rate of C. bovis was higher in cows in late lactation.

O objetivo deste estudo foi descrever um surto de sarna corióptica em bovinos, 56 anos após a sua primeira identificação no Brasil. Entre os meses de junho a julho de 2011, a dermatite caracterizada por alopecia, com crosta e espessamento da pele na inserção da cauda e na fossa isquiorretal, foi observada em 40 (35,7%) de 112 vacas holandesas de uma propriedade rural pertencente à Mesorregião do Nordeste do Estado do Rio Grande do Sul, Brasil. Após o diagnóstico da sarna causada por Chorioptes bovis, as vacas foram pesadas, tratadas com 0,5% de ivermectina pour on em dose única e separadas em dois grupos: vacas no início da lactação e no final da lactação. A taxa de sobrevivência de C. bovis e a taxa de cura dos dois grupos de vacas infestadas foram monitoradas a cada sete dias por meio de raspas de pele. Após 28 dias do estudo, a taxa de cura com o tratamento foi maior em vacas no início da lactação (p <0,0001). A taxa de sobrevivência de C. bovis foi maior em vacas no final da lactação.

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.

Avaliação citogenética de frentistas expostos ao benzeno em postos de gasolina de Campo Maior, PI / Cytogenetic assessment of attendants exposed to benzene in gas stations in Campo Maior, PI

O biomonitoramento do risco ocupacional em trabalhadores expostos ao benzeno e derivados é realizado como diagnóstico e prevenção de danos a curto e longo prazo ao material genético. Testes de curta duração que determinam o perigo genético são categorizados pelos indicadores biológicos que avaliam mutação gênica, dano cromossômico ou lesão no DNA. A associação íntima desses indicadores fortalece a importância dos testes de genotoxicidade. O estudo objetiva avaliar o risco de mutagenicidade e anormalidades nucleares em indivíduos expostos ao benzeno. Avaliaram-se células da mucosa oral (teste de micronúcleos), sangue periférico (hemograma automatizado) de vinte frentistas da cidade de Campo Maior, PI, e o do grupo controle, além da aplicação do questionário de estudo epidemiológico. Relacionaram-se os resultados ao estilo de vida desses profissionais. A frequência de micronúcleos no grupo exposto foi significativa (***P,0,0001/Student's test), assim como a frequência de anormalidades nucleares para cariólise (**P<0,001) e para binucleação (*P<0,05). A frequência de cariólise e etilismo (r= 0,464) também apresentou uma correlação positiva(P*<0,05). Evidenciou-se que essa exposição ao petróleo e derivados induz mutagenicidade, citotoxicidade e apoptose, sendo necessário, por isso, conscientizar empregadores e trabalhadores dos postos de gasolina sobre o uso de EPI e intensificar o monitoramento ocupacional.

Genotoxic effects of oral-exposed TiO2 nanoparticles on bone marrow cells in young rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the genotoxic effects of oral-exposed TiO2 nanoparticles on bone marrow cells in young rats.</p><p><b>METHODS</b>Twenty-eight SD male young rats (4 weeks old) were randomly divided into 4 groups, which were exposed to TiO2 nanoparticles ((75 ± 15) nm, anatase) through intragastric administration at 0, 10, 50 and 200 mg/kg body weight (bw) every day for 30 days. The bone marrow cells were collected for micronuclei and γ-H2AX immunofluorescence analysis.</p><p><b>RESULTS</b>The percentage of γ-H2AX foci-positive cells (37.4 ± 10.0)% in the 50 mg/kg bw dose group were significantly higher than that in the control group (19.8 ± 3.1)% (t value was -17.59, P < 0.01). No significantly difference was found in polychromatic erythrocyte/normochromatic erythrocyte (PCE/NCE) ratio and PCE micronucleus rate between three experimental groups and control group.</p><p><b>CONCLUSION</b>TiO2 nanoparticles can increase the frequency of DNA double-strand breaks in bone marrow cells, but has no effect on micronucleus of bone marrow cells in young rats.</p>

Effects of polymorphisms in XRCC1 and APE1 on vinyl chloride-induced chromosome damage / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of polymorphisms in XRCC1 and APE1 genes on vinyl chloride (VC)-induced chromosomal damage in peripheral lymphocytes.</p><p><b>METHODS</b>In this study, 317 workers occupationally exposed to VC were recruited from a factory in Shandong Province, China. The micronucleus (MN) frequency in peripheral lymphocytes was used as an indicator of chromosomal damage. Polymerase chain reaction-restriction fragment length polymorphism and created restriction site combined with restriction fragment length polymorphism were used to determine the five single nucleotide polymorphisms in XRCC1 and APE1 genes in the base excision repair pathway. The association of chromosomal damage with these polymorphisms and the haplotype of XRCC1 was analyzed using Poisson regression and PHASE 2.0.2.</p><p><b>RESULTS</b>It was found that among the VC-exposed workers, individuals with XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) had a significantly higher MN frequency than those with homozygous wild-type genotypes, with frequency ratios (FR) as follows, respectively: FR = 1.21, 95%CI: 1.05∼1.39 (P < 0.05); FR = 1.14, 95%CI: 1.00∼1.38 (P < 0.05); FR = 1.26, 95%CI: 1.11∼1.44 (P < 0.05); FR = 1.23, 95%CI: 1.08∼1.46 (P < 0.05). APE1 Asp148Glu was found of no significant relationship with MN frequency. Haplotype analysis of XRCC1 demonstrated that the MN frequencies in subjects with CTAA/CTAA and CCAA/CTAA were significantly higher than that in those with TCGG/TCGG (FR = 1.19, 95%CI: 1.02∼1.32, P < 0.05; FR = 1.41, 95%CI: 1.02∼1.87, P < 0.05). Furthermore, association was found between accumulated exposure to VC and XRCC1 polymorphisms (-77C/T, Arg194Trp, Arg280His, and Arg399Gln) after adjustment for age, sex, drinking, and smoking.</p><p><b>CONCLUSION</b>VC can induce chromosomal damage even when the exposure level is lower than the national occupational health standard of China (PC-TWA: 10 mg/m(3)); the polymorphisms in XRCC1 and APE1 are associated with chromosomal damage induced by VC.</p>

Estudio comparativo de la frecuencia de micronúcleos y anormalidades nucleares en eritrocitos de tres especies ícticas / Comparative studies of the frequency of micronuclei and nuclear abnormalities in erythrocytes of three species fishes

Los ecosistemas acuáticos cercanos a las zonas urbanas sufren un deterioro constante ocasionado por diversos factores físico-químicos relacionados con la actividad antrópica, representando un riesgo para los organismos que los habitan, en especial los peces. Estos efectos pueden ser biomonitoreados mediante técnicas de amplia utilización, como el Test de Micronúcleos (Mn) y el de Anormalidades nucleares (AN), entre otros. El objetivo de este trabajo fue verifcar y comparar la frecuencia de micronúcleos y anormalidades nucleares en tres especies ícticas colectadas en un lago urbano, Cyprinus carpio, Astyanax eigenmanniorum y Cheirodon interruptus. Luego de la captura y anestesia de los peces, se extrajo de cada individuo una muestra de sangre y se registró el peso y la longitud total. Las muestras fueron fjadas y luego teñidas con Giemsa al 10%, posteriormente se las analizó con microscopio (1000X) y se les tomaron fotografías con cámara digital. Se calculó, además, el índice de condición corporal (K) para cada uno de los ejemplares capturados. Se aplicó un análisis de correlación de rangos de Spearman (rs) entre frecuencia de Mn y AN vs K para cada especie. La prueba de Kruskal-Wallis se aplicó para evaluar diferencias de Mn y AN entre las especies. Los resultados no mostraron una correlación estadísticamente signifcativa (P> 0,05) entre las frecuencias de Mn y AN vs K. Las frecuencias de Mn entre las diferentes especies no arrojaron diferencias signifcativas (P> 0,05), mientras que las AN sí (P< 0,05). Astyanax eigenmanniorum fue la especie que mayor sensibilidad presentó. Las diferencias preliminares de AN entre las especies utilizadas, convierten a A. eigenmanniorum en una especie "centinela" y posible biomonitor de agentes xenobióticos.

Aquatic ecosystems near urban areas suffer a steady deterioration caused by physical and chemical factors related to human activity, representing a danger to organisms that inhabit them, especially the fsh. These effects may be biomonitored by widely used techniques, such as the Micronucleus Test (Mn) and Nuclear Abnormalities (NA), among others. The aim of this study was to verify and compare the frequency of micronuclei and nuclear abnormalities in three fsh species collected in an urban lake, Cyprinus carpio, Astyanax eigenmanniorum and Cheirodon interruptus. After the capture and anesthesia of the fsh, weight and length were registered, and a blood sample was obtained from each individual. The samples were fxed and stained with 10% Giemsa, subsequently they were analyzed with the microscope (1000X) and photographed with a digital camera. The body con-dition index (K) was calculated for each fsh caught. A correlation analysis Spearman rank (rs) between frequency of Mn and NA vs. K was performed for each species. The Kruskal-Wallis test was applied to assess differences in Mn and NA between species. The results showed no statistically signifcant correlation (P> 0.05) between the frequencies of Mn and NA vs K. The frequencies of Mn between different species yielded no signifcant differences (P> 0.05), whereas NA (P <0.05) did. A. eigenmanniorum was the most sensitive species. NA preliminary differences between the species used, convert A. eigenmanniorum in a sort of "sentinel specie" and a possible biomonitor of xenobiotic agents.

Analysis of micronuclei in buccal epithelial cells in patients subjected to panoramic radiography.

Context: Ionizing radiation is a well-known carcinogen in humans. Chromosomal aberrations and formation of micronuclei in cell cytoplasm are early biological evidence of carcinogenesis. Aims: This study was undertaken to assess the genotoxic effect of panoramic radiography in the buccal epithelial cells. Materials and Methods: The study included 60 healthy individuals (median age 23.5 years; age range 12-65 years) who underwent panoramic radiographic examination. Exfoliated buccal epithelial cells were obtained immediately before and 10 days after radiation exposure. The cells were stained with Giemsa and evaluated for micronuclei by scoring 1000 cells per sample. Statistical analysis used: The paired 't ' test was used to find out the significance of difference in the number of micronuclei before and after x-ray exposure. The Karl Pearson correlation coefficient was used to find out the correlation between age and micronucleated cell frequencies and number of micronucleus per 1000 cells. The ANOVA test was used to find out if there were significant differences in micronucleated cell frequencies between different age-groups. Student's unpaired 't' test was used to find out the significance of difference in micronucleated cell frequencies and number of micronucleus per 1000 cells between genders. Results: The paired 't' test showed that micronucleated cell frequencies (P = 0.02) and number of micronucleus per 1000 cells (P = 0.047) were significantly higher after radiographic exposure. The mean number of micronucleated cells before and after radiation exposure were 0.48 ± 0.14 and 0.51 ± 0.15, respectively. There was statistically significant increase in the frequency of micronuclei in buccal epithelial cells after exposure to panoramic radiography. The correlation of micronucleus frequency with age and gender was statistically nonsignificant. Conclusions: The results indicate that panoramic radiography may induce genotoxic effects in buccal epithelial cells. Considering this risk, panoramic radiography should be used cautiously.

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.

Comparación entre dos biomodelos murinos (ratones Balb/c y ratas Sprague Dawley) en el ensayo de micronúcleos transplacentarios / Comparison between two murine biomodles (Balb/c mice and Sprague Dawley rats) in a transplacental micronucleus assay

Objetivo: comparar fetos de ratones Balb/c y ratas Sprague Dawley como biomodelos en el ensayo de micronúcleos transplacentarios, determinando la frecuencia espontánea e inducida, y vincular el efecto genotóxico y reproductivo. Métodos: se formaron tres grupos experimentales/especie: control negativo (simulacro), control solvente NaCl (0,9 %) y ciclofosfamida 50 mg/kg. Todos los grupos se administraron por vía intraperitoneal los días 14, 15 y 16 de la gestación, y 24 h después de la última inoculación en ratones y 48 h en ratas se procedió a realizar la eutanasia de las gestantes, para obtener las muestras de hígado fetal. Resultados: los fetos de ratas Sprague Dawley demostraron tener menores índices de citotoxicidad y de genotoxicidad, y se obtuvieron los resultados más bajos de micronúcleos endógenos. Los mejores resultados de inducción de citotoxicidad y genotoxicidad por la alta formación de micronúcleos con ciclofosfamida fueron en fetos de ratas Sprague Dawley, los que resultaron más susceptibles al daño genotóxico de este mutágeno. Se corroboró el poder clastogénico transplacentario de la ciclofosfamida, vinculando este ensayo de genotoxicidad a toxicología de la reproducción. Conclusiones: los resultados sugieren el mejor uso de fetos de ratas Sprague Dawley como biomodelo en este ensayo cuando es utilizada la ciclofosfamida como control positivo por la vía y dosis estudiada; además, se pudieran utilizar en la evaluación de nuevas drogas con carácter antigenotóxico por vía transplacentaria.

Objectives: to compare fetuses from Balb/c mice and Sprague Dawley rats as biomodels in transplacental micronuclei assay and to determine the spontaneous and induced frequency to link the genotoxic and reproductive effect. Methods: three experimental groups by species were formed: a negative control (simulation), NaCl (0.9 %) solvent control and 50 mg/kg cyclophosphamide. All the groups were intraperitoneally administered at 14th, 15th and 16th days of gestation, and 24 h after the last inoculation in mice and 48 h in rats, it proceeded to perform euthanasia in the pregnant animals to obtain the fetal liver samples. Results: the fetuses from Sprague Dawley exhibited smaller cytotoxicity and genotoxicity indexes, and the lowest endogenous micronucleus results. The best results of the cytotoxicity and genotoxicity induction for the high micronucleus formation with cyclophosphamide were found in Sprague Dawley rat fetuses, being more susceptible to the genotoxic damage by this mutagen. The clastogenic transplacental power of cyclophosphamide was confirmed whereas this genotoxicity assay was linked to reproduction toxicology. Conclusions: these results suggest that the Sprague Dawley rats fetuses could be better used as biomodels in this assay when cyclophosphamide is employed as positive control through the way of administration and the studied dosage. It could be similarly used in the evaluation of new antigenotoxic drugs with antigenotoxic effect through transplacental administration.

Protective effect of an extract of Guipi Pill against radiation-induced damage in mice / 中国结合医学杂志

<p><b>OBJECTIVE</b>To study the protective effect of an extract of Guipi Pill () against radiation-induced damage.</p><p><b>METHODS</b>A total of 100 Kunming mice were randomly divided into normal group, model group, positive drug group (treated with radioprotective agent "523", 5 mg/kg at 24 h before irradiation) and two treatment groups, with 20 mice in each group. The extract of water extraction-alcohol precipitation (WAP) from Guipi Pill were administered orally to the mice in the two treatment groups at the dose of 500 and 1,000 mg/kg, respectively, for 6 days prior to whole body radiation (8 Gy). Fifty mice with 10 in each group were used to observe the survival rate 30 days after radiation. The other 50 mice with 10 in each group were sacrificed on day 10 after radiation (6 Gy) in order to take blood, liver and unilateral femur.</p><p><b>RESULTS</b>Pretreatment prior to irradiation with WAP resulted in a significantly higher 30-day survival rate of mice after exposure to a potentially lethal dose of 8-Gy radiation. WAP could significantly increase the total white blood cell count and DNA content of bone marrow, and it also increased the activity of various antioxidant enzymes, such as superoxide dismutase, catalase, total antioxidant capacity and glutathione peroxidase in liver tissue of mice, which were reduced by radiation treatment. Maleic dialdehyde level and bone marrow micronucleus rate were significantly reduced by WAP, which were increased after 6-Gy radiation.</p><p><b>CONCLUSION</b>WAP of Guipi Pill could increase the 30-day survival rate and the antioxidant capacity as well as protect bone marrow in mice. WAP of Guipi Pill is an effective radioprotective agent.</p>

Polymorphism of XRCC1 and chromosome damage in workers occupationally exposed to benzene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the relationship between the polymorphisms of DNA repair gene (XRCC1 194, 280 and 399) and the chromosomal damage induced by benzene.</p><p><b>METHODS</b>The chromosomal damage of the peripheral lymphocytes in 459 workers occupationally exposed to benzene and 88 non-exposed controls were detected with cytokinesis-block micronucleus (CBMN) assay. PCR-RFLP technique was used to measure polymorphisms in XRCC1 194, 280 and 399.</p><p><b>RESULTS</b>It was found that the MN frequency (2.12‰ ± 1.88‰) of the exposed group was significantly higher than that (1.19‰ ± 1.68‰) of the control group (P < 0.05), in the exposed group, the MN frequency (3.00‰ ± 2.76‰) of older workers (> 35 years) was significantly higher than that (2.02‰ ± 1.71‰) of younger workers (≤ 35 years) (P < 0.05). The effect of genetic polymorphisms of XRCC1 on CBMN was not found. The haplotypes AAA/BAA, AAB/AAB, ABA/ABA, ABB/ABB could associated with the increased frequencies of total micronucleus (P < 0.05).</p><p><b>CONCLUSION</b>Benzene exposure could result in chromosome damage. Age of workers and diplotypes of XRCC1 could associated with chromosomal damage induced by benzene.</p>

Using the stable HSPA1A promoter-driven luciferase reporter HepG2 cells to assess the overall toxicity of coke oven emissions / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>Using the stable HSPA1A (HSP70-1) promoter-driven luciferase reporter HepG2 cells (HepG2/HSPA1A cells) to assess the overall toxicity of coke oven emissions.</p><p><b>METHODS</b>The stable HepG2/HSPA1A cells were treated with different concentrations of coke oven emissions (COEs) collected from the top, side, and bottom of a coke oven battery for 24 h. After the treatments, luciferase activity, cell viability, malondialdehyde (MDA) concentration, Olive tail moment, and micronuclei frequency were determined, respectively.</p><p><b>RESULTS</b>The bottom COEs induced significant increases (P < 0.01) in relative luciferase activity up to 1.4 times the control level at 0.15 µg/L. The low dose of side COEs (0.02 µg/L) led to a significant increase (P < 0.01) in relative luciferase activity that progressively increased to 2.1 times the control level at 65.4 µg/L. The top COEs produced a strong dose-dependent induction of relative luciferase activity up to over 5 times the control level at the highest concentration tested (202 µg/L). In HepG2/HSPA1A cells treated with the bottom COEs, relative luciferase activity was positively correlated with MDA concentration (r = 0.404, P < 0.05). For the three COEs samples, positive correlations were observed between relative luciferase activity and Olive tail moment and micronuclei frequency.</p><p><b>CONCLUSION</b>The relative luciferase activity in HepG2/HSPA1A cells can sensitively reflect the overall toxicity of COEs. The stable HepG2/HSPA1A cells can be used for rapid screening of the overall toxicity of complex air pollutants in the workplace.</p>