Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts （URE）, and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C ...Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts （URE）, and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C （MMC）. Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts （URE） were studied using chromosome aberration （CA）, sister chromatid exchange （SCE）, and micronuclei （MN） tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 lag/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC （P〈0.0001）. Conclusion Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.展开更多
The frequency of micronuclei (MN) in cells of the nasal mucosa, oral mucosa and in lym-phocytes was evaluated for 25 students in anatomy classes exposed to formaldehyde (FA) overan 8-week period. Each student served a...The frequency of micronuclei (MN) in cells of the nasal mucosa, oral mucosa and in lym-phocytes was evaluated for 25 students in anatomy classes exposed to formaldehyde (FA) overan 8-week period. Each student served as his or her own control. The time-weighted averageconcentration (TWA) of fOrmaldehyde in anatomical laboratories and in students' dormitorieswas 0. 508 ± 0. 299 mg/m3 and 0. 012 ± 0. 0025mg/m3, respectively. A higher frequency ofmicronuclei was observed in nasal and oral exfoliative cells after formaldehyde exposure (3. 85± 1. 48 vs 1 .20± 0. 676 and 0. 857 ± 0. 558 vs 0. 568 ± 0. 317, paired-t test: P< 0. 001and P < 0. 01, respectively). No significant increase in the frequency of lymphocyte micronu-clei was found after formaldehyde exposure (P >0. 05 ). The present study shows that nasalmucosa cel1s exposed through respiration are the chief target of FA-induced genotoxic effects展开更多
Since the first report by Nagasawa et al.[1] in 1992, which demonstrates evidences that non-irradiated bystandercells also showed damage of sister chromatid exchange in samples irradiated with low-dose α particles, r...Since the first report by Nagasawa et al.[1] in 1992, which demonstrates evidences that non-irradiated bystandercells also showed damage of sister chromatid exchange in samples irradiated with low-dose α particles, radiationinduced bystander effect (RIBE) has been studied for more than decades and many publications showed that RIBEswere found after treatment of both low and high-LET radiations. However, there are also some reports showingcontrary facts that no obvious bystander effects can be found, for example Fournier et al.[2] reported that theyobserved no early cytogenetic damage in the bystander cells after heavy ion microbeam irradiation. RIBE is ofgreat interest in radiotherapy using X-ray radiation or high-LET heavy ions because of RIBE-related cell killing andcarcinogenesis in neighboring normal cells[3]. In this work, we investigated the damage in bystander cells exposedto medium from cells irradiated with X-ray and carbon beam.展开更多
To put forward a method of automatic recognition of the micronuclei on computerized image in bi-nucleated lymphocytes. Methods: The procedure was as the follows: ① The nuclei and cytoplasm images were automatically e...To put forward a method of automatic recognition of the micronuclei on computerized image in bi-nucleated lymphocytes. Methods: The procedure was as the follows: ① The nuclei and cytoplasm images were automatically extracted from the background in order that the nuclei and cytoplasm images could be preprocessed individually.② Noise in two images was reduced, the edges in the nuclei image smoothed and then the big-point noise in the cytoplasm image taken off. ③ The nuclei was identified and the single cytoplasm acquired individually form nuclei and cytoplasm image. ④ The two preprocessed images were put together to identify the bi-nuclei and micronuclei form the overlapped map. Results: Many new models for image processing have been established. Preliminary measurement showed that the accuracy of recognition reached a high percentage of 85%. Conclusion: It is of great value to put the automatic recognition system into use.展开更多
Background and Objectives: Chronic low-dose exposure to dichlorvos occurs in communities in Africa where the substance is used indiscriminately for a variety of purposes. This experiment used an animal model to evalua...Background and Objectives: Chronic low-dose exposure to dichlorvos occurs in communities in Africa where the substance is used indiscriminately for a variety of purposes. This experiment used an animal model to evaluate genomic instability induced by this pattern of chronic exposure and its relationship with some measures of fertility in males. Methods: Seventy-five male Rattus norvegicus rats obtained for this experiment, were randomly allotted into five groups. Dichlorvos was given by oral gavage at doses of 0.28 mg/kg, 0.56 mg/kg and, 1.68 mg/kg, respectively, to three of the groups, on alternate days for 50 weeks. The remaining two groups received plain drinking water and cyclophosphamide as negative and positive controls, respectively. Samples were collected at 17, 34, and 50 weeks. Sperm count, sperm morphology and serum levels of follicle-stimulating hormone, luteinizing hormone, dihydrotestosterone, oestrogen and progesterone were determined. Furthermore, the frequency of micronucleated polychromatic erythrocytes was determined in bone marrow cells obtained from the femur. Results: The mean ranks of micronuclei frequency had an increasing trend. The frequency of micronucleated polychromatic erythrocytes (MnPCE) had a significant negative correlation with oestrogen (r<sub>s</sub> = -0.47, p = 0.00, n = 50), follicle-stimulating hormone (r<sub>s</sub> = -0.41, p = 0.00, n = 50) and progesterone (r<sub>s</sub> = -0.37, p = 0.01, n = 50) serum levels. A positive monotonic relationship also existed between micronuclei frequency and those of tubular necrosis, tubular vacuolation, and residual bodies. A positive significant moderate correlation was found between MnPCE and the proportion of immotile sperms (r<sub>s</sub> = 0.41, p = 0.00, n = 50). Conclusion: The nature of the correlations between micronuclei frequency and the proportion of immotile sperms, adverse histological changes and serum hormone levels found in this study suggest genomic instability as the possible mechanism for diminished fertility in males chronically exposed to dichlorvos.展开更多
研究了液态和气态甲醛对雄性小鼠生殖细胞的毒作用.选用SPF级昆明种纯系雄性小鼠作为研究对象,液态甲醛染毒剂量分别为0.20,2.00,20.00 m g/kg体重,采用腹腔注射染毒7 d,观察睾丸组织的病理改变,并计算脏器系数、精子存活率、活动率、...研究了液态和气态甲醛对雄性小鼠生殖细胞的毒作用.选用SPF级昆明种纯系雄性小鼠作为研究对象,液态甲醛染毒剂量分别为0.20,2.00,20.00 m g/kg体重,采用腹腔注射染毒7 d,观察睾丸组织的病理改变,并计算脏器系数、精子存活率、活动率、精子数及畸形率.气态甲醛染毒剂量分别为0.5,1.0,3.0 m g/m3,连续动态染毒72 h,于首次染毒后第15天观察睾丸细胞的微核率.结果表明,液态甲醛能引起睾丸组织病理损伤,脏器系数、精子存活率、活动率和精子数减少,畸形率升高;气态甲醛能诱导早期精细胞微核率增加,均呈现一定的剂量-反应关系.液态甲醛和气体甲醛均具有小鼠生殖细胞毒性.展开更多
基金supported by a grant from the Scientific and Technical Research Council of Turkey, Ankara (TüBiTAK, 107T279 (TBAG/HD-304).
文摘Objective To determine the in vitro possible clastogenic and cytotoxic activities of Ulva rigida crude extracts （URE）, and identify their antigenotoxic and protective effects on chemotherapeutic agent mitomycine-C （MMC）. Methods Anti-clastogenic and anti-genotoxic activities of Ulva rigida crude extracts （URE） were studied using chromosome aberration （CA）, sister chromatid exchange （SCE）, and micronuclei （MN） tests in human lymphocytes cultured in vitro. Results The chromosome aberration, sister chromatid exchange or micronuclei tests showed that URE at concentrations of 10, 20, and 40 lag/mL had no clastogenic activity in human lymphocyte cell culture. Three doses of URE significantly decreased the number of chromosomal aberrations and the frequencies of SCE and MN when compared with the culture treated with MMC （P〈0.0001）. Conclusion Although URE itself is not a clastogenic or cytotoxic substance, it possesses strong antigenotoxic, anti-clastogenic, and protective effects on MMC in vitro.
文摘The frequency of micronuclei (MN) in cells of the nasal mucosa, oral mucosa and in lym-phocytes was evaluated for 25 students in anatomy classes exposed to formaldehyde (FA) overan 8-week period. Each student served as his or her own control. The time-weighted averageconcentration (TWA) of fOrmaldehyde in anatomical laboratories and in students' dormitorieswas 0. 508 ± 0. 299 mg/m3 and 0. 012 ± 0. 0025mg/m3, respectively. A higher frequency ofmicronuclei was observed in nasal and oral exfoliative cells after formaldehyde exposure (3. 85± 1. 48 vs 1 .20± 0. 676 and 0. 857 ± 0. 558 vs 0. 568 ± 0. 317, paired-t test: P< 0. 001and P < 0. 01, respectively). No significant increase in the frequency of lymphocyte micronu-clei was found after formaldehyde exposure (P >0. 05 ). The present study shows that nasalmucosa cel1s exposed through respiration are the chief target of FA-induced genotoxic effects
文摘Since the first report by Nagasawa et al.[1] in 1992, which demonstrates evidences that non-irradiated bystandercells also showed damage of sister chromatid exchange in samples irradiated with low-dose α particles, radiationinduced bystander effect (RIBE) has been studied for more than decades and many publications showed that RIBEswere found after treatment of both low and high-LET radiations. However, there are also some reports showingcontrary facts that no obvious bystander effects can be found, for example Fournier et al.[2] reported that theyobserved no early cytogenetic damage in the bystander cells after heavy ion microbeam irradiation. RIBE is ofgreat interest in radiotherapy using X-ray radiation or high-LET heavy ions because of RIBE-related cell killing andcarcinogenesis in neighboring normal cells[3]. In this work, we investigated the damage in bystander cells exposedto medium from cells irradiated with X-ray and carbon beam.
文摘To put forward a method of automatic recognition of the micronuclei on computerized image in bi-nucleated lymphocytes. Methods: The procedure was as the follows: ① The nuclei and cytoplasm images were automatically extracted from the background in order that the nuclei and cytoplasm images could be preprocessed individually.② Noise in two images was reduced, the edges in the nuclei image smoothed and then the big-point noise in the cytoplasm image taken off. ③ The nuclei was identified and the single cytoplasm acquired individually form nuclei and cytoplasm image. ④ The two preprocessed images were put together to identify the bi-nuclei and micronuclei form the overlapped map. Results: Many new models for image processing have been established. Preliminary measurement showed that the accuracy of recognition reached a high percentage of 85%. Conclusion: It is of great value to put the automatic recognition system into use.
文摘Background and Objectives: Chronic low-dose exposure to dichlorvos occurs in communities in Africa where the substance is used indiscriminately for a variety of purposes. This experiment used an animal model to evaluate genomic instability induced by this pattern of chronic exposure and its relationship with some measures of fertility in males. Methods: Seventy-five male Rattus norvegicus rats obtained for this experiment, were randomly allotted into five groups. Dichlorvos was given by oral gavage at doses of 0.28 mg/kg, 0.56 mg/kg and, 1.68 mg/kg, respectively, to three of the groups, on alternate days for 50 weeks. The remaining two groups received plain drinking water and cyclophosphamide as negative and positive controls, respectively. Samples were collected at 17, 34, and 50 weeks. Sperm count, sperm morphology and serum levels of follicle-stimulating hormone, luteinizing hormone, dihydrotestosterone, oestrogen and progesterone were determined. Furthermore, the frequency of micronucleated polychromatic erythrocytes was determined in bone marrow cells obtained from the femur. Results: The mean ranks of micronuclei frequency had an increasing trend. The frequency of micronucleated polychromatic erythrocytes (MnPCE) had a significant negative correlation with oestrogen (r<sub>s</sub> = -0.47, p = 0.00, n = 50), follicle-stimulating hormone (r<sub>s</sub> = -0.41, p = 0.00, n = 50) and progesterone (r<sub>s</sub> = -0.37, p = 0.01, n = 50) serum levels. A positive monotonic relationship also existed between micronuclei frequency and those of tubular necrosis, tubular vacuolation, and residual bodies. A positive significant moderate correlation was found between MnPCE and the proportion of immotile sperms (r<sub>s</sub> = 0.41, p = 0.00, n = 50). Conclusion: The nature of the correlations between micronuclei frequency and the proportion of immotile sperms, adverse histological changes and serum hormone levels found in this study suggest genomic instability as the possible mechanism for diminished fertility in males chronically exposed to dichlorvos.
文摘研究了液态和气态甲醛对雄性小鼠生殖细胞的毒作用.选用SPF级昆明种纯系雄性小鼠作为研究对象,液态甲醛染毒剂量分别为0.20,2.00,20.00 m g/kg体重,采用腹腔注射染毒7 d,观察睾丸组织的病理改变,并计算脏器系数、精子存活率、活动率、精子数及畸形率.气态甲醛染毒剂量分别为0.5,1.0,3.0 m g/m3,连续动态染毒72 h,于首次染毒后第15天观察睾丸细胞的微核率.结果表明,液态甲醛能引起睾丸组织病理损伤,脏器系数、精子存活率、活动率和精子数减少,畸形率升高;气态甲醛能诱导早期精细胞微核率增加,均呈现一定的剂量-反应关系.液态甲醛和气体甲醛均具有小鼠生殖细胞毒性.
