DNA damages in mouse hepatocytes and lymphocytes induced by aniline and their repair dynamics / 中国实验动物学报

Objective To investigate the genotoxicity of aniline and repair dynamics in hepatocytes and lymph-cytes.Methods Aniline was administered intragastrically to SPF Kunming mice ( five mice in each group) in a single dose of 100 mg/kg body weight.The hepatocytes and peripheral blood lymphocytes were obtained at 3, 8, 16, 24, and 32 hours after aniline administration, respectively.The control mice received tap water only.The DNA damages were detected by single cell gel electrophoresis assay ( SCGE) and the time-effect relationship was analyzed.Results The results of SCGE experiment showed that both the tail lenth and tail moment of the hepatocyte DNA were increased gradually from 8 h, and reached the maximum at 16 h ( P0.05).The two DNA damage indexes of peripheral blood lymphocytes started to increase at 16 h, reached the maxi-mum at 24 h ( P<0.01) , and began to recover at 32 h after aniline administration.Conclusions Our findings suggeste that aniline may be a potential genotoxicant to hepatocytes and peripheral blood lymphocytes.There is a clear time-response relationship in terms of the two DNA damage indexes, indicating that hepatocytes and lymphocytes in mice possess an effi-cient DNA repair mechanism against aniline toxicity.

Assessing extent of single stranded DNA damage in oral mucosal cells of patients with oral squamous cell carcinoma and its correlation with TNM staging.

Context: This study was carried out on the assumption that oral mucosal cells might show DNA damage in oral squamous cell carcinoma (OSCC). Aims: To evaluate the extent of DNA damage in oral smears of patients with OSCC and determine correlation if any of the extent of DNA damage to TNM staging of oral cancer. Settings and design: A randomized controlled study at a regional cancer centre was designed for this project. Smears were taken from lesion proper of 30 patients with OSCC and from the buccal mucosa of 30 normal healthy volunteers. Materials and methods: Collected cells were centrifuged and single-cell gel electrophoresis (SCGE) assay was performed. DNA damage was visualized under a fluorescent microscope. Statistical analysis used : Mean DNA damage levels of both the groups were measured and statistically analyzed with students' test. The extent of DNA damage was correlated with the TNM stages by employing the one way ANOVA 'F' technique. Results: High statistical significance (P < 0.0001) was found in DNA damage levels between control and study groups. A stepwise increase in DNA damage levels with high statistical significance (P < 0.005) was also found between all the TNM stages. Conclusions: Statistically significant increased DNA damage levels in OSCC patients and their correlation to clinical staging suggest that comet assay may be used effectively to assess the prognosis of OSCC.

Daño basal del ADN en un grupo de individuos cubanos sanos mediante ensayo Cometa alcalino / Basal DNA damage on a group of Cuban healthy individuals by alkaline Comet assay / Dano basal no DNA em um grupo de indivíduos cubanos saudáveis através do ensaio Cometa alcalino

El ADN de las células humanas está sujeto de forma constante a diferentes tipos de daños debido a factores ambientales y a procesos metabólicos propios de la célula, que de no ser reparados y renovada su integridad, provocan inestabilidad genómica. Consecuentemente el daño en el ADN ha sido utilizado como marcador biológico en el biomonitoreo humano. El objetivo del presente trabajo fue determinar el daño basal del ADN en linfocitos aislados de sangre periférica de individuos voluntarios sanos, sin antecedentes patológicos y/o exposición a agentes genotóxicos. Se incluyó un total de 95 sujetos residentes en La Habana, con una edad promedio de 34±12 años, en los que el 71,13% correspondió a mujeres. Se empleó la variante alcalina del ensayo Cometa. Los niveles de daño fueron determinados en unidades arbitrarias. El daño basal del ADN, cuantificado en los 95 individuos, fue de 34,98±19,6 UA (25%=20,5 UA, 75%=47,5 UA). Los valores determinados constituyen los valores de referencia del laboratorio para el daño basal del ADN, en sujetos sanos. El punto de corte de daño al ADN, correspondiente al percentil 75, presenta aplicabilidad en el estudio de pacientes e individuos expuestos a xenobióticos. El uso de este valor permite la realización de estrategias de intervención oportunas que contribuyan a reparar tempranamente el daño detectado.

Human cell DNA is constantly subject to different types of damage due to environmental factors and metabolic processes of the same cell, which cause genomic instability if not repaired and completely renewed. Consequently, DNA damage has been used as a biomarker in human biomonitoring. The aim of this study was to determine basal DNA damage in lymphocytes isolated from peripheral blood of healthy volunteers with no medical history and/or exposure to genotoxic agents. A total of 95 subjects from the western region of Cuba, with an average age of 34±12 years, 71.13% of whom were female were included. Alkaline Comet assay variant was used. Damage levels were determined in arbitrary units. Basal DNA damage, measured in 95 subjects, was 34.98 ± 19.6 AU (25% = 20.5 AU, 75% = 47.5 AU). The values determined are the laboratory reference values for basal DNA damage in healthy subjects. The cutoff of DNA damage, corresponding to 75 percentile, has applicability in the study of patients and subjects exposed to xenobiotics. Use of this value allows for the realization of appropriate intervention strategies that help early repair of the damage detected.

O DNA das células humanas está constantemente sujeito a diferentes tipos de danos devido a fatores ambientais e a processos metabólicos próprios da célula, que se não forem reparados e a sua integridade renovada, provocam instabilidade genômica. Por conseguinte, o dano no DNA foi utilizado como um biomarcador no biomonitoramento humano. O objetivo deste estudo foi determinar o dano basal do DNA em linfócitos isolados de sangue periférico de voluntários saudáveis, sem antecedentes patológicos e/ou exposição a agentes genotóxicos. Um total de 95 indivíduos residentes em Havana foram incluídos, com uma idade em média de 34±12 dos quais 71,13% eram mulheres. Foi utilizada a variante alcalina do ensaio Cometa. Os níveis de dano foram determinados em unidades arbitrárias. O dano basal do DNA, medido nos 95 pacientes, foi de 34,98 ± 19,6 UA (25% = 20,5 UA, 75%=47,5 UA). Os valores determinados são os valores de referência do laboratório para o dano basal do DNA em indivíduos saudáveis. O ponto de corte de dano ao DNA, correspondente ao 75 percentil, tem aplicabilidade no estudo de pacientes e indivíduos expostos a xenobióticos. O uso deste valor permite a realização de estratégias de intervenção adequadas que ajudem a reparar precocemente o dano detectado.

DNA Damage in Lymphocytes after Hair Dyeing and Related Factors among Women Volunteers / 예방의학회지

OBJECTIVES: To evaluate the DNA damage by hair dyeing in human lymphocytes. METHODS: Comet assays were carried out to evaluate the DNA damage in lymphocytes by hair dyeing. Twenty subjects were selected from women volunteers whose age ranged from 55 to 67 year old. All subjects had no smoking history. Blood samples were collected before and 6 hours after hair dyeing. DNA damage was evaluated by means of the tail moments, which were quantified by a KOMET 4.0 image analysis system. RESUJLTS: The tail moments before hair dyeing showed no significant differences among subjects except for the high frequency group. The mean values of the tail moments in subjects with low and high frequencies of hair dyeing were 1.39 and 1.77, respectively (p<0.05). The tail moments after hair dyeing increased significantly. The mean values of tail moments in subjects before and after hair dyeing were 1.45 and 1.79, respectively (p<0.01). However, the difference levels of DNA damage in lymphocytes before and after hair dyeing were found to be slightly lower in both the dietary supplement taking group and high frequency group. CONCLUSIONS: The high frequency group appears to have a higher level of DNA damage than the low frequency group before hair dyeing. DNA damage in lymphocytes was found to be significantly higher in the volunteers after hair dyeing. In this study, the related factors such as high frequency and taking dietary supplements appeard to reduce DNA damage in lymphocytes after hair dyeing.

DNA Damage in Lymphocytes after Hair Dyeing and Related Factors among Women Volunteers / 예방의학회지

OBJECTIVES: To evaluate the DNA damage by hair dyeing in human lymphocytes. METHODS: Comet assays were carried out to evaluate the DNA damage in lymphocytes by hair dyeing. Twenty subjects were selected from women volunteers whose age ranged from 55 to 67 year old. All subjects had no smoking history. Blood samples were collected before and 6 hours after hair dyeing. DNA damage was evaluated by means of the tail moments, which were quantified by a KOMET 4.0 image analysis system. RESUJLTS: The tail moments before hair dyeing showed no significant differences among subjects except for the high frequency group. The mean values of the tail moments in subjects with low and high frequencies of hair dyeing were 1.39 and 1.77, respectively (p<0.05). The tail moments after hair dyeing increased significantly. The mean values of tail moments in subjects before and after hair dyeing were 1.45 and 1.79, respectively (p<0.01). However, the difference levels of DNA damage in lymphocytes before and after hair dyeing were found to be slightly lower in both the dietary supplement taking group and high frequency group. CONCLUSIONS: The high frequency group appears to have a higher level of DNA damage than the low frequency group before hair dyeing. DNA damage in lymphocytes was found to be significantly higher in the volunteers after hair dyeing. In this study, the related factors such as high frequency and taking dietary supplements appeard to reduce DNA damage in lymphocytes after hair dyeing.