No abstract available.
Chromium* ; Micronucleus Tests*

Cytokinesis ; Micronucleus Tests

Cytokinesis ; Humans ; Lymphocytes ; pathology ; Micronucleus Tests ; Neoplasms ; genetics ; Risk Factors

PURPOSE: Calcium phosphate cement (CPC) is one of many useful materials for restoring tooth defects, periodontium and maxillofacial area. Chitosan is a biodegradable material that has been shown to promote the growth and differentiation of osteoblasts in culture. This study examined the interaction between odontoblasts and bio-calcium phosphate cement reinforced with chitosan. MATERIALS AND METHODS: 5x10(3) odontoblastic cells were seeded into each well. Various concentrations of bio-calcium phosphate cement reinforced with chitosan (10, 20, 50, 100, 200, 500 microg/ml, 1, 2, 4 mg/ml) were diluted and added to the wells. The well was incubated for 24 h, 48 h and 72 h. After incubation, the number of cells was assessed to determine the cell viability. A cytokinesis-block micronucleus assay and chromosomal aberration test were carried out to estimate the extent of chromosomal abnormalities. Microscopic photographs and RT-PCR were performed to examine the adhesion potential of bio-calcium phosphate cement reinforced with chitosan. RESULTS: Bio-CPC-reinforced chitosan did not show significant cytotoxicity. The number of damaged chromosomes in the cells treated with Bio-CPC-reinforced chitosan was similar to that in the control cells. There was no significant increase in the number of chromosomal aberrations in the Bio-CPC reinforced chitosan exposed cells. Microscopic photographs and RT-PCR confirmed the adhesive potential of bio-CPC reinforced chitosan to odontoblasts. CONCLUSION: Bio-CPC-reinforced chitosan did not affect the odontoblastic cell viability, and had no significant cytotoxic effect. Bio-CPC-reinforced chitosan showed adhesive potential to odontoblasts. These results are expected form the basis of future studies on the effectiveness of dental restorative materials in Bio-CPC reinforced with chitosan.
Adhesives ; Calcium ; Calcium Phosphates ; Cell Survival ; Chitosan ; Chromosome Aberrations ; Micronucleus Tests ; Odontoblasts ; Osteoblasts ; Periodontium ; Seeds ; Tooth

OBJECTIVE: This study evaluated the cytotoxicity and genotoxicity of fixed orthodontic treatment with three different light-cured orthodontic bonding composites by analyzing micronucleus (MN) formation in the buccal mucosa during a 6-month period. METHODS: Thirty healthy volunteers were selected from consecutive patients referred for orthodontic treatment. Equilibrium 2 brackets and molar tubes (Dentaurum) were bonded with three different light-cured orthodontic bonding composites-Transbond XT (3M Unitek), Kurasper F (Kuraray Europe), or GrenGloo (Ormco Corporation)- to all teeth in both arches. Exfoliated buccal epithelial cells were scraped from the middle part of the inner cheeks with sterile cement spatulas before treatment and at 1, 3, and 6 months after treatment. MNs and nuclear alterations, such as karyorrhexis (KR), karyolysis (KL), and binucleated cells (BNs), were scored under a light microscope. Repeated measure ANOVA was used to calculate statistical differences in degenerative nuclear abnormalities. RESULTS: MN rates did not significantly differ among different time points within the same cell type (p > 0.05). In contrast, the number of BNs in buccal epithelial cells significantly increased in all composite groups (p < 0.01, Transbond XT; p < 0.001, Kurasper F and GrenGloo). KL frequency significantly increased between the beginning and end of the study in the Kurasfer F (0.80 +/- 0.79 to 1.90 +/- 1.10; p < 0.05) and GrenGloo (1.30 +/- 1.06 to 2.40 +/- 1.08; p < 0.05) groups. CONCLUSIONS: After 6 months of fixed orthodontic treatment with different light-cured composites, morphological signs of cytotoxicity were observed but genotoxic effects were absent.
Cheek ; Epithelial Cells* ; Healthy Volunteers ; Humans ; Micronucleus Tests* ; Molar ; Mouth Mucosa ; Tooth

PURPOSE: The purpose of this study was to develop in vivo dosimetries using both chromosomal aberrations and micronuclei in mice to assess biological effects of radiations. MATERIALS AND METHODS: Five each mice were irradiated with 0, 1, 2, 3, 4, 5, 10 Gy of Cs-137 gamma-rays. We scored numbers of chromosomal aberrations in metaphase spreads and numbers of micronuclei in bone marrow smears under light microscope, and obtained the dose-response relationships. We also examined the relationship between the two dose-response curves. RESULTS: The frequency of both chromosomal aberrations and micronuclei increased with dose, in a linear-quadratic manner. The delta, beta, and alpha coefficients were 0.0176, 0.0324, and 0.0567 for metaphase analysis (r=1.0, p<0.001) and 0.0019, 0.0073, and 0.0506 for micronuclei assay (r=1.0, p<0.001). The frequency of chromosomal aberrations and micronuclei in diffirent radiation doses was significantly correlated (r=0.99, p<0.01). CONCLUSION: In vivo dosimetry using either metaphase analysis or micronucleus assay was feasible in mice. These methods could be useful to evaluate biological effects of radiation.
Animals ; Bone Marrow Cells* ; Bone Marrow* ; Chromosome Aberrations ; Metaphase* ; Mice* ; Micronucleus Tests

PURPOSE: Radiation adaptive response in human peripheral lymphocytes and mouse bone marrow cells was investigated using both metaphase analysis and micronucleus assay. We assessed the correlation between both tests. MATERIALS AND METHODS: Two groups of the human peripheral lymphocytes and mouse bone marrow cells were exposed to low dose (conditioning dose, 0.18 Gy) or high dose (challenging dose, 2 Gy) gamma-rays. The other 4 groups were exposed to low dose followed by high dose after several time intervals (4, 7, 12, and 24 hours, respectively). The frequencies of chromosomal aberrations in metphase analysis and micronuclei in micronucleus assay were counted. RESULTS: Chromosomal aberrations and micronuclei of preexposed group were lower than those of the group only exposed to high dose radiation. Maximal reduction in frequencies of chromosomal aberrations were observed in the group to which challenging dose was given at 7 hour after a conditioning dose (p<0.001). Metaphase analysis and micronucleus assay revealed very good correlation in both human lymphocytes and mouse bone marrow cells (r=0.98, p<0.001; r=0.99, p=0.001, respectively). CONCLUSION: Radiation adaptive response could be induced by low dose irradiation in both human lymphocytes and mouse bone marrow cells. There was a significant correlation between metaphase analysis and micronucleus assay
Animals ; Bone Marrow Cells* ; Bone Marrow* ; Chromosome Aberrations ; Cytogenetics* ; Humans* ; Lymphocytes* ; Metaphase* ; Mice* ; Micronucleus Tests

OBJECTIVETo explore the relationship between genetic polymorphism of P53, P21, CCND1 and susceptibility of chromosomal damage induced by vinyl chloride monomer (VCM).

METHODS183 workers occupationally exposed to VCM were involved in our study. Cytokinesis-block micronucleus (CB-MN) assay was used to detect chromosome damage in peripheral lymphocyte. PCR-RFLP technique was applied to detect polymorphisms in P53 gene (exon4, intron3 and intron6), P21 gene (exon2 and exon3) and CCND1 (exon4).

RESULTSThe risk of chromosomal damage for VCM-exposed workers with more than 30 yr was 1.2202 (95% CI: 1.0580 approximately 1.4072, P = 0.0062) compared with the younger workers, and the risk of female workers was 1.1491 (95% CI: 0.9841 approximately 1.3416, P = 0.0772) compared with male workers. The MN frequency in subjects with P53 intron6 mutant homozygous and heterozygous was higher than their wild-type homozygous counterparts (OR = 1.3032, 95% CI: 1.1285 approximately 1.6405, P = 0.0285). P53 exon4, intron3 and intron6 haplotype pairs of BBB/AAA and BAB/AAA were associated with the increased frequencies of micronucleus.

CONCLUSIONAmong VCM-exposed workers, more than 30ys, female, carrying P53 intron6 mutated allele and BBB/AAA and BAB/AAA haplotype pairs have higher risk of chromosomal damage.

Cell Cycle Checkpoints ; Humans ; Micronucleus Tests ; Occupational Exposure ; Polymorphism, Genetic ; Vinyl Chloride

OBJECTIVEThe health surveillance proposal for chromate exposed workers was provided and analyzed on the evidence-based study and then to be improved.

METHODFirstly, the related literatures were searched about liver damage, micronuclei, urinary chromium and hexavalent chromium exposure in Evidence Based Medicine Reviews such as Cochran library, OVID Medline, Web of knowledge in December 2011; and then, these literatures were reviewed in according to inclusion and exclusion criteria; 22 articles totally were retrieved, evaluated and classified in according to the grading standard by Oxford Centre for Evidence-based Medicine.Finally, field epidemiological investigation was further adopted to confirm the efficiency and feasibility of this proposal, combined with cost-effectiveness analysis:the ratio of total cost divided survival years was used to express the cost-effectiveness.

RESULTOnly the glutamic pyruvic transaminase test could not reflect liver damage caused by chromate exposure well; Urinary chromium correlated well with the index reflecting body damage caused by chromate exposure; Binucleated cells micronucleus index in peripheral blood lymphocyte could reflect the genetic damage caused by chromate exposure. As for health economic evaluation of chromate lung cancer, the value of cost/effectiveness was ¥42 321.61 per year that was far below the value of common people (¥252 868.97 per year) .

CONCLUSIONIt was suggested that serum glutamic pyruvic transaminase test should be replaced by liver function test, urinary chromium should be classified as a compulsory index and binucleated cells micronucleus index in peripheral blood lymphocyte should be supplied as a recommended index.

Alanine Transaminase ; blood ; Chromates ; urine ; Evidence-Based Medicine ; Humans ; Micronucleus Tests ; Occupational Exposure ; Population Surveillance

OBJECTIVETo investigate the association of rs2910164 G > C polymorphism and rs11614913 T > C polymorphism in pre-miR-146a and pre-miR-196a2 with genetic damage levels in coke oven workers.

METHODSA total of 575 nonsmoking workers who have worked for more than one year in a coke-oven plant at Wuhan, Hubei Province were enrolled in this study in September to October, 2010. The general characteristics as well as blood and urine samples were collected. The genetic damage levels were detected by cytokinesis-block micronucleus cytom assay and represented as micronucleus (MN) frequencies of binucleate cells in peripheral blood lymphocytes. The rs2910164 G > C polymorphisms in pre-miR-146a and rs11614913 T > C polymorphisms in pre-miR-196a2 were genotyped by using TaqMan assay. The plasma concentrations of benzo[a]pyrene-diolepoxide (BPDE)-albumin adducts were determined by using ELISA. All data were analyzed, the frequency ratio (FR) and 95%CI were calculated.

RESULTSTotally, 575 workers were taken into consideration. The rs2910164 C allele was associated with increased MN frequencies in the coke oven workers (P trend = 0.025), and the MN frequencies were higher in rs2910164 CC genotype carriers (4.38 ± 3.46) than in wild-type rs2910164 GG genotype carriers (4.02 ± 3.09) (FR = 1.18, 95%CI:1.04-1.34). The further stratified analyses by working years, gender, alcohol consumption, and the levels of BPDE-albumin adducts showed that the effects of rs2910164 C allele in increasing MN frequencies were robust in subjects who were males (FR = 1.11, 95%CI:1.02-1.20), nondrinkers (FR = 1.07, 95%CI:1.00-1.14), working years less than 20 (FR = 1.12, 95%CI:1.03-1.22), and workers with lower BPDE-albumin adducts levels (FR = 1.11, 95%CI:1.02-1.21) (P trend = 0.011, 0.044, 0.006 and 0.020, respectively). In addition, the MN frequencies were higher in workers with rs11614913 TC genotype (4.27 ± 2.91) than workers with rs11614913 TT genotype (3.90 ± 3.32) (FR = 1.12, 95%CI:1.02-1.23).Workers carried both rs2910164 GG and rs11614913 TT genotypes were set as a control, and the MN frequencies of workers with both rs2910164 CC and rs11614913 CC genotypes (5.32 ± 4.94) were 1.51 (1.21-1.89) times higher than the control (3.75 ± 3.01).

CONCLUSIONThe rs2910164 C allele in pre-miR-146a and rs11614913 C allele in pre-miR-196a2 were associated with increased genetic damage levels in coke oven workers.

Adult ; Alleles ; Coke ; Female ; Genotype ; Humans ; Male ; MicroRNAs ; genetics ; Micronucleus Tests ; Occupational Exposure ; Polymorphism, Single Nucleotide