Cationic-vacancy-induced room-temperature ferromagnetism in transparent, conducting anatase Ti1-xTaxO2 (x~0.05) thin films

We report room-temperature ferromagnetism (FM) in highly conducting, transparent anatase Ti(1-x)Ta(x)O(2) (x∼0.05) thin films grown by pulsed laser deposition on LaAlO(3) substrates. Rutherford backscattering spectrometry (RBS), X-ray diffraction, proton-induced X-ray emission, X-ray absorption spectroscopy (XAS) and time-of-flight secondary-ion mass spectrometry indicated negligible magnetic contaminants in the films. The presence of FM with concomitant large carrier densities was determined by a combination of superconducting quantum interference device magnetometry, electrical transport measurements, soft X-ray magnetic circular dichroism (SXMCD), XAS and optical magnetic circular dichroism, and was supported by first-principles calculations. SXMCD and XAS measurements revealed a 90 per cent contribution to FM from the Ti ions, and a 10 per cent contribution from the O ions. RBS/channelling measurements show complete Ta substitution in the Ti sites, though carrier activation was only 50 per cent at 5 per cent Ta concentration, implying compensation by cationic defects. The role of the Ti vacancy (V(Ti)) and Ti(3+) was studied via XAS and X-ray photoemission spectroscopy, respectively. It was found that, in films with strong FM, the V(Ti) signal was strong while the Ti(3+) signal was absent. We propose (in the absence of any obvious exchange mechanisms) that the localized magnetic moments, V(Ti) sites, are ferromagnetically ordered by itinerant carriers. Cationic-defect-induced magnetism is an alternative route to FM in wide-band-gap semiconducting oxides without any magnetic elements.

SIRT1 induces EMT by cooperating with EMT transcription factors and enhances prostate cancer cell migration and metastasis

The epithelial-to-mesenchymal transition (EMT) is a crucial program for the invasion and metastasis of epithelial tumors that involves loss of cell-cell adhesion and increased cell mobility; however, mechanisms underlying this transition are not fully elucidated. Here, we propose a novel mechanism through which the nicotinamide adenine dinucleotide-dependent histone deacetylase SIRT1 regulates EMT in prostate cancer cells through cooperation with the EMT inducing transcription factor ZEB1. We found that forced expression of SIRT1 in non-transformed PZ-HPV-7 prostate epithelial cells disrupts the epithelial morphology concomitant with decreased expression of the epithelial marker, E-cadherin, and increased expression of mesenchymal markers. In contrast, silencing SIRT1 in metastatic prostate tumor cells restores cell-cell adhesion and induces a shift toward an epithelial morphology concomitant with increased expression of E-cadherin and decreased expression of mesenchymal markers. We also found that SIRT1 has a physiologically relevant role in endogenous EMT induced by EGF signaling in prostate cancer cells. We propose that the regulation of EMT by SIRT1 involves modulation of, and cooperation with, the EMT inducing transcription factor ZEB1. Specifically, we show that SIRT1 silencing reduces expression of ZEB1 and that SIRT1 is recruited to the E-cadherin proximal promoter by ZEB1 to deacetylate histone H3 and to reduce binding of RNA polymerase II, ultimately suppressing E-cadherin transcription. We thus identify a necessary role for ZEB1 in SIRT1-mediated EMT. Finally, we show that reduction of SIRT1 decreases prostate cancer cell migration in vitro and metastasis in vivo in immunodeficient mice, which is largely independent of any general effects of SIRT1 on prostate cancer growth and survival. We therefore identify SIRT1 as a positive regulator of EMT and metastatic growth of prostate cancer cells and our findings implicate overexpressed SIRT1 as a potential therapeutic target to reverse EMT and to prevent prostate cancer progression.

Characterizing hepatocellular carcinoma using multi-breath-hold two-dimensional susceptibility-weighted imaging: comparison to conventional liver MRI

AIM

To characterize the imaging manifestations of hepatocellular carcinoma (HCC) using multi-breath-hold two-dimensional susceptibility-weighted imaging (SWI) and compare to conventional liver magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Forty-three patients with histopathologically confirmed HCC underwent conventional liver MRI, multi-breath-hold two-dimensional SWI, and contrast-enhanced CT preoperatively. The T1-weighted imaging (WI), T2WI, and SWI images were evaluated in consensus by two experienced radiologists. The tumour boundaries, blood products in the tumour, venous vessels, and non-tumour liver parenchyma were compared.

RESULTS

SWI demonstrated significantly better tumour boundary detection than T1WI and T2WI imaging (67.4 and 25.6%, respectively). The detection rate for intra-tumoural blood products using SWI was higher than that of T1WI and T2WI (76.7 and 16.3%, respectively). The detection rate for tumour venous vessels using SWI was 72.1%, while none was detected with conventional T1WI and T2WI. The detection rate for siderotic nodules in non-tumour liver parenchyma using SWI was higher than that of conventional T1WI and T2WI (65.1 and 20.9%, respectively).

CONCLUSIONS

SWI can provide more detailed information than conventional liver MRI in evaluation of tumour boundaries, blood products, venous vasculature, and non-tumour liver parenchyma. SWI is a valuable complement to conventional liver MRI.

MicroRNA-155 inhibits proliferation and migration of human extravillous trophoblast derived HTR-8/SVneo cells via down-regulating cyclin D1

MiR-155 is known to participate in various cellular processes by targeting gene expression. We previously revealed a link between miR-155 and perturbation of trophoblast invasion and differentiation. This study aimed to investigate the target molecule(s) of miR-155 on the influence on the proliferation and migration of trophoblast cells. Bioinformatics analysis showed that, at the 3' untranslated region (UTR) of cyclin D1, six bases are complementary to the seed region of miR-155. Luciferase assays and cyclin D1 3'UTR transfection assays validated that cyclin D1 3'UTR was the target of miR-155 in HTR-8/SVneo cells. Overexpression of miR-155 in HTR-8/SVneo cells reduced the level of cyclin D1 protein, decreased cell proliferation and invasion, and increased cell number at the G1 stage. Furthermore, the increased expression of miR-155 also regulated the protein levels of kinase inhibitory protein p27 and phosphorylated cytoskeletal protein filamin A. In conclusion, we found that cyclin D1 may be a target of miR-155 in HTR-8/SVneo cells, and demonstrated a negative regulatory role of miR-155 involved in cyclin D1/p27 pathway in proliferation and migration of the cells.

Development and validation of a parenting assessment tool for Chinese parents

OBJECTIVE

The objective of this study was to develop a parenting assessment tool (PAT) for parents of children aged 3 to 6 years to assess parenting attitudes and skills within the Chinese socio-cultural context.

METHODS AND PARTICIPANTS

Focus group discussions were used to gather information for composing the PAT test items. Factor analysis was performed to build and refine the factor structure of PAT. Ten cities included in a larger programme, the Early Childhood Development Promotion Project carried out by the Capital Institute of Pediatrics in China, were chosen as the study area. Six hundred and twelve parents and their single children were chosen from those 10 cities by convenience sampling for the large-scale investigation of PAT, and the results were used to test and validate the psychometric properties of PAT.

RESULTS

The internal consistency of total PAT scores was 0.87, and those of the eight subscales ranged from 0.53 to 0.79. Test-retest reliability over 2 weeks was also significant for the total scores and all subscales (range: 0.68-0.89). For the factor structure, an eight-factor solution accounting for 65.54% of the variance was most consistently fit. Concurrent validity was supported by significant positive correlations between total PAT scores and children's language ability, sociability and adaptive ability as assessed by the Developmental Diagnostic Scale of Children Aged 0-6 Years.

CONCLUSIONS

The newly devised PAT test is a reliable instrument to assess the parenting skills and attitudes of parents of young children in urban China.

Microchemical inhomogeneity to characterize atomic configurations in the heating and quenching of a CuHf2 alloy

Based on the constructed Cu-Hf interatomic potential, Monte Carlo simulations were conducted to reveal the atomic configurations in heating and quenching of a CuHf(2) alloy through scrutinizing the evolution of microchemical inhomogeneity. Simulations show that the CuHf(2) crystalline structure becomes more homogeneous during heating but an obvious drop in microchemical inhomogeneity appears when reaching its melting point. During the quenching process, the CuHf(2) melt becomes increasingly inhomogeneous and shows a change in the slope in the microchemical inhomogeneity around glass transition temperature. Simulation results were evidenced by the atomic packing analysis through the Voronoi tessellation method. The implications of our study suggest that the glass transition could be visualized as a process involving increase of microchemical inhomogeneity from the liquid to glassy state.

Character of chicken polymorphic major histocompatibility complex class II alleles of 3 Chinese local breeds

To better understand the major histocompatibility complex (MHC) genetic character of domestic birds, we sequenced and analyzed chicken MHC II (B-L) genes of 3 local chicken breeds, derived from 3 separate areas in China. We amplified cDNA sequences from 105 individuals, accounting for 35 alleles. Some of the same B-LB alleles with a high frequency were found in all samples. The putative B-L α-chain had few polymorphic sites, whereas the B-L β-chain had several polymorphic sites. Most of the mutation positions were located in the B-LB β1 domain encoded by exon 2, especially in the peptide-binding region. This indicated that the highly polymorphic peptide-binding region could potentiate binding diverse antigen epitopes. The comparison of 3-D molecule structures of chicken B-L and human HLA-DR1 revealed a distinctly structural similarity, but the chicken B-L molecule had more polymorphic sites than the human HLA-DR1 molecule, which presumably might be a mechanism to compensate for responding to a wider array of pathogens due to fewer loci for chicken. Moreover, some conserved sites in human and chicken MHC class II molecules reflected their common ancestry and similar functions. These results suggest that the chicken B-L gene showed more polymorphic sites and distinctly dominant trans-breed alleles, potentially to adapt to pathogens.

Genetic damage induced by organic extract of coke oven emissions on human bronchial epithelial cells

Coke oven emissions are known as human carcinogen, which is a complex mixture of polycyclic aromatic hydrocarbon. In this study, we aimed to clarify the mechanism of action of coke oven emissions induced carcinogenesis and to identify biomarkers of early biological effects in a human bronchial epithelial cell line with CYP1A1 activity (HBE-CYP1A1). Particulate matter was collected in the oven area on glass filter, extracted and analyzed by GC/MS. DNA breaks and oxidative damage were evaluated by alkaline and endonucleases (FPG, hOGG1 and ENDO III)-modified comet assays. Cytotoxicity and chromosomal damage were assessed by the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay. The cells were treated with organic extract of coke oven emissions (OE-COE) representing 5, 10, 20, 40μg/mL extract for 24h. We found that there was a dose-effect relationship between the OE-COE and the direct DNA damage presented by tail length, tail intensity and Olive tail moment in the comet assay. The presence of lesion-specific endonucleases in the assays increased DNA migration after OE-COE treatment when compared to those without enzymes, which indicated that OE-COE produced oxidative damage at the level of pyrimidine and purine bases. The dose-dependent increase of micronuclei, nucleoplasmic bridges and nuclear buds in exposed cells was significant, indicating chromosomal and genomic damage induced by OE-COE. Based on the cytotoxic biomarkers in CBMN-Cyt assay, OE-COE may inhibit nuclear division, interfere with apoptosis, or induce cell necrosis. This study indicates that OE-COE exposure can induce DNA breaks/oxidative damage and genomic instability in HBE-CYP1A1 cells. The FPG-comet assay appears more specific for detecting oxidative DNA damage induced by complex mixtures of genotoxic substances.

Sirtuin 1 (SIRT1) and steroid hormone receptor activity in cancer

Sirtuins, which are class III NAD-dependent histone deacetylases that regulate a number of physiological processes, play important roles in the regulation of metabolism, aging, oncogenesis, and cancer progression. Recently, a role for the sirtuins in the regulation of steroid hormone receptor signaling is emerging. In this mini-review, we will summarize current research into the regulation of estrogen, androgen, progesterone, mineralocorticoid, and glucocorticoid signaling by sirtuins in cancer. Sirtuins can regulate steroid hormone signaling through a variety of molecular mechanisms, including acting as co-regulatory transcription factors, deacetylating histones in the promoters of genes with nuclear receptor-binding sites, directly deacetylating steroid hormone nuclear receptors, and regulating pathways that modify steroid hormone receptors through phosphorylation. Furthermore, disruption of sirtuin activity may be an important step in the development of steroid hormone-refractory cancers.

Neurotrophic effect of bone marrow mesenchymal stem cells for erectile dysfunction in diabetic rats

It has been demonstrated that intracavernous injection of bone marrow-derived mesenchymal stem cells (BM-MSCs) had beneficial effects on improving erectile function in type-1 diabetic rats. This study was designed to investigate the neurotrophic effect of BM-MSCs for type-1 diabetic rats. Streptozocin-induced type-1 diabetic rats were randomly divided into three groups: diabetic group, BM-MSCs-treated group and BM-MSCs-conditioned medium-treated group. At the 3d, 1 and 2w time points after BM-MSCs injection, three randomly selected rats in MSCs group were sacrificed and penile samples were harvested to detect BM-MSCs in penile tissue. Four weeks after intracavernous injection of BM-MSCs or BM-MSCs-conditioned medium, intracavernous pressure (ICP) was assessed to evaluate the erectile function. Immunohistochemistry was used to track labelled BM-MSCs in penile tissue and to detect neuronal nitric oxide synthase (nNOS) and neurofilament (NF) positive fibres in penile dorsal nerve. Enzyme lined immunosorbent assay (ELISA) was used to measure the concentrations of vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in BM-MSCs-conditioned medium. BM- MSCs secreted detectable levels of VEGF, BDNF and NGF. Intracavernous injection of BM-MSCs improved erectile function in diabetic rats. The functional improvement was accompanied by promoted nNOS and NF positive nerve fibres within penile dorsal nerve in type-1 diabetic rats. Histological data revealed a time-dependent decrease in the number of BM-MSCs in the corpus cavernosum following injection. Furthermore, the beneficial effect of BM-MSCs was partially repeated by BM-MSCs-conditioned medium. Intracavernous injection of BM-MSCs is effective in improving nerve regeneration in diabetic rats. Paracrine effects of BM-MSCs are probably involved in the improvement.

Association of interleukin-13 C-1112T and G+2044A polymorphisms with asthma: a meta-analysis

BACKGROUND AND OBJECTIVE

Polymorphisms in the IL13 gene have been reported to be associated with susceptibility to asthma. However, a number of studies have shown inconsistent results. A meta-analysis was performed to investigate whether polymorphisms in the IL13 gene were associated with the risk of asthma.

METHODS

Searches were performed of the Medline and Chinese National Knowledge Infrastructure (CNKI) databases, covering all papers published up to 31 August 2010. A recently proposed logistic regression-based method for meta-analysis of case-control genetic association studies was used to analyse pooled data. All statistical analyses were performed using stata version 10.0 software.

RESULTS

The IL13 C-1112T and G+2044A polymorphisms were investigated in 10 and 14 studies, respectively. The summary estimates suggested that both these polymorphisms were associated with susceptibility to asthma. Carriers of the IL13 -1112T allele had a 38.9% increased risk of asthma compared with homozygotes (-1112CC) (odds ratio (OR) 1.389, 95% confidence interval (CI): 1.103-1.749). Carriers of the IL13+2044A allele had a 40.0% increased risk of asthma compared with homozygotes (+2044GG) (OR 1.400, 95% CI: 1.137-1.724). In a subgroup analysis by ethnicity, the IL13 -1112T allele was associated with an increased risk of asthma among Caucasians (OR 1.629, 95% CI: 1.255-2.113) but not among Asians, and the IL13+2044A allele was associated with an increased risk of asthma among Asians (OR 1.436, 95% CI: 1.101-1.873) but not among Caucasians.

CONCLUSIONS

This meta-analysis indicated that the IL13 C-1112T and G+2044A polymorphisms predispose to asthma. Further studies, including pooling of individual data to facilitate evaluation of gene-gene and gene-environment interactions between these IL13 gene polymorphisms and asthma susceptibility, are recommended.

Polymorphisms of NOD2 and the risk of tuberculosis: a validation study in the Chinese population

A genome-wide association study (GWAS) of leprosy reported four specific genetic polymorphisms of NOD2 that were associated with susceptibility to Mycobacterium leprae in China. Considering the role of NOD2 in innate immune defence, we performed a study in a Chinese population to determine whether the same SNPs of NOD2 that were associated with disease caused by M. leprae were also associated with disease caused by Mycobacterium tuberculosis. We performed a frequency-matched case-control study in 1043 patients with pulmonary tuberculosis and 808 unaffected controls. All subjects were >15 years old and were Han Chinese from Jiangsu Province. We extracted DNA from a blood sample from each study participant. SNPs of rs3135499, rs7194886, rs8057341 and rs9302752 in the NOD2 gene were genotyped using a TaqMan-based allelic discrimination system. Using all possible patients with tuberculosis as cases, no significant association was found between the four specific SNPs and the risk of tuberculosis. In a subgroup analysis restricted to cases with bacteriologically confirmed tuberculosis (sputum culture positive), the variant genotype of rs7194886 was significantly associated with an altered risk of tuberculosis. Compared with the CC genotype, individuals carrying the CT/TT genotype of rs7194886 had an increased risk [odds ratio (OR) 1.35, 95% confidence interval (CI) (1.05-1.72)]. The association was stronger among tobacco smokers and males. By haplotype analysis, rs9302752C-rs7194886T was associated with an increased risk of bacteriologically confirmed tuberculosis (sputum culture positive) (P = 0.039), but it was not significant after correcting for multiple comparisons. In summary, genetic polymorphisms of the SNP rs7194886 in the NOD2 gene, which were discovered in the GWAS of leprosy, might also be associated with the pulmonary tuberculosis in the Chinese population.

Proliferation of dental follicle-derived cell populations in heat-stress conditions

OBJECTIVES

Isolation and purification of adult stem cells (ASC) are a great challenge. Our objectives were to determine whether ASC are more heat-tolerant than non-stem cells, and to explore if ASC could be enriched by heat-stress treatments.

MATERIALS AND METHODS

Rat dental follicle cells were cultured in a variety of media to obtain either a heterogeneous cell population (H-DFC) consisting of stem cells and non-stem cells, or a homogenous cell population (DFC) containing non-stem cells only. Real-time RT-PCR was conducted to compare expression of heat-shock proteins (HSPs) between the two populations. To study heat tolerance, H-DFC and DFC were incubated under heat-stress conditions and cell proliferation was evaluated by alamar blue reduction assay. Furthermore, cells resulting from heat-stress treatments were evaluated for differentiation capability and expression of stem cell markers.

RESULTS

H-DFC expressed higher levels of HSP110, HSP70s and HSP27s than did DFC. H-DFC increased levels of proliferation at 40 °C compared to controls grown at 37 °C; no significant reduction in proliferation occurred at temperatures below 40.5 °C. In contrast, DFC showed significant reduction in proliferation under all heat-stress treatments. Heat-stressed H-DFC had increased differentiation capability and increased expression of stem cell markers.

CONCLUSION

Stem cells appear to be more tolerant to heat stress than non-stem cells. Incubation of a heterogeneous cell population in heat-stress conditions resulted in increased stem cell numbers.

Different iron-deposition patterns of multiple system atrophy with predominant parkinsonism and idiopathetic Parkinson diseases demonstrated by phase-corrected susceptibility-weighted imaging

BACKGROUND AND PURPOSE

MSA-P and IPD have similar clinical presentations that may complicate accurate clinical diagnosis. Different iron-deposition patterns of those 2 diseases have been demonstrated in histopathology. The aim was to demonstrate the different iron-deposition patterns of MSA-P and IPD by using SWI phase images.

MATERIALS AND METHODS

Sixteen patients with IPD, 8 with MSA-P, and 44 age-matched healthy controls underwent SWI of brain. The different phase shifts as well as the high iron percentage of the area in several gray nuclei were statistically evaluated. The putamen was divided into 4 subregions for further analysis.

RESULTS

Patients with MSA-P had significantly higher iron deposition in the putamen and PT compared with those with IPD (P < .05). Moreover, ROC curves indicated slightly more sensitivity in differentiating MSA-P from IPD, by means of the high-iron-deposition-percentage area than the average phase shift (putamen: AUC = 0.88 versus 0.78; PT: AUC = 0.79 versus 0.62). Moreover, the lower inner region of the putamen was the most valuable subregion in differentiating MSA-P from IPD among the 4 subregions (AUC = 0.92 and 0.91 for high-iron-percentage area and average phase shift, respectively).

CONCLUSIONS

Higher iron deposition in the putamen and PT may differentiate MSA-P from IPD, but the lower inner region of the putamen may be better compared with the PT and other subregions of the putamen. Moreover, the high iron percentage makes it possible to detect smaller increases in iron content more confidently in comparison with average phase shift.

Inhibition of β-catenin signaling by nongenomic action of orphan nuclear receptor Nur77

Dysregulation of β-catenin turnover due to mutations of its regulatory proteins including adenomatous polyposis coli (APC) and p53 is implicated in the pathogenesis of cancer. Thus, intensive effort is being made to search for alternative approaches to reduce abnormally activated β-catenin in cancer cells. Nur77, an orphan member of the nuclear receptor superfamily, has a role in the growth and apoptosis of cancer cells. Here, we reported that Nur77 could inhibit transcriptional activity of β-catenin by inducing β-catenin degradation via proteasomal degradation pathway that is glycogen synthase kinase 3β and Siah-1 independent. Nur77 induction of β-catenin degradation required both the N-terminal region of Nur77, which was involved in Nur77 ubiquitination, and the C-terminal region, which was responsible for β-catenin binding. Nur77/ΔDBD, a Nur77 mutant lacking its DNA-binding domain, resided in the cytoplasm, interacted with β-catenin, and induced β-catenin degradation, demonstrating that Nur77-mediated β-catenin degradation was independent of its DNA binding and transactivation, and might occur in the cytoplasm. In addition, we reported our identification of two digitalis-like compounds (DLCs), H-9 and ATE-i2-b4, which potently induced Nur77 expression and β-catenin degradation in SW620 colon cancer cells expressing mutant APC protein in vitro and in animals. DLC-induced Nur77 protein was mainly found in the cytoplasm, and inhibition of Nur77 nuclear export by the CRM1-dependent nuclear export inhibitor leptomycin B or Jun N-terminal kinase inhibitor prevented the effect of DLC on inducing β-catenin degradation. Together, our results demonstrate that β-catenin can be degraded by cytoplasmic Nur77 through their interaction and identify H-9 and ATE-i2-b4 as potent activators of the Nur77-mediated pathway for β-catenin degradation.

1H NMR-based metabolomic study of metabolic profiling for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease characterized by multi-system involvement, diverse clinical presentation, and alterations in circulating metabolites. In this study, a 1H NMR spectroscopy-based metabolomics approach was applied to establish a human SLE serum metabolic profile. Serum samples were obtained from patients with SLE ( n = 64), patients with rheumatoid arthritis (RA) ( n = 30) and healthy controls ( n = 35). The NOESYPR1D spectrum combined with multi-variate pattern recognition analysis was used to cluster the groups and establish a disease-specific metabolites phenotype. Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) models were capable of distinguishing SLE or RA patients from healthy subjects. The OPLS-DA model was able to predict diagnosis of SLE with a sensitivity rate of 60.9% and a specificity rate of 97.1%. For diagnosing RA, the model has much higher sensitivity (96.7%) and specificity (91.4%). The SLE serum samples were characterized by reduced concentrations of valine, tyrosine, phenylalanine, lysine, isoleucine, histidine, glutamine, alanine, citrate, creatinine, creatine, pyruvate, high-density lipoprotein, cholesterol, glycerol, formate and increased concentrations of N-acetyl glycoprotein, very low-density lipoprotein and low-density lipoprotein in comparison with the control population. Theresults not only indicated that serum NMR-based metabolomic methods had sufficient sensitivity and specificity to distinguish SLE and RA from healthy controls, but also have the potential to be developed into a clinically useful diagnostic tool, and could also contribute to a further understanding of disease mechanisms.

Successful organ donation from brain dead donors in a Chinese organ transplantation center

Solid organ transplantation is an effective treatment for patients with end-stage organ failure. Donation after brain death (DBD) is a means of addressing the inadequate supply of acceptable donor organs but has only gradually begun to be accepted in mainland China. A major barrier has been the absence of brain death and organ transplant legislation. This paper describes our initial experience with organ transplantation using organs from brain dead donors and discusses strategies for encouraging organ transplantation and brain death legislation in China. Six patients underwent renal transplantation and two patients underwent liver transplantation with organs procured from three brain dead donors at the Organ Transplantation Center, the 181st Hospital. All patients are alive with excellent graft function. DBD is an important means of increasing the number of organs available for transplantation and its widespread implementation in China should be encouraged. Brain death and organ transplantation legislation is necessary to ensure the rights and obligations of donors, recipients and medical institutions.

Modulation of DNA repair capacity by ataxia telangiectasia mutated gene polymorphisms among polycyclic aromatic hydrocarbons-exposed workers

The purpose of this study was to address the association between the ataxia telangiectasia mutated (ATM) gene polymorphisms and susceptibility to DNA repair capacity (DRC) among polycyclic aromatic hydrocarbons (PAHs)-exposed workers. Polymorphisms of ATM were genotyped. DRC was determined by comet assay. Chromosomal damage was detected by cytokinesis-block micronucleus (CBMN) assay. Flow cytometry was used to detect the distributions of cell cycle. Expressions of ATM and rH2AX were determined by immunoblotting analysis. Luciferase assays were performed to determine the functional difference of ATM promoter region allele. Subjects carrying T allele of rs228589 had significantly lower DRC compared with those with AA genotype. Subjects carrying G allele of rs652311 had significantly lower DRC than those with zero copy number of haplotype CGGT. SH ataxia telangiectasia mutated (SHATM) cells had significantly lower DRC than SH green fluorescent protein (SHGFP) cells induced by bleomycin and higher CBMN frequencies treated by benzo(a)pyrene [B(a)P] than SHGFP cells. After B(a)P treatment, a decrease in the percentage of G1 phase cells was observed in SHATM cells compared with SHGFP cells, rH2AX expressions were increased in SHATM cells and SHGFP cells, but ATM expressions had no change in 16HBE-SHGFP cells and HEK-SHGFP cells. Luciferase expression was not different between rs228589T and rs228589A plasmid constructs. In conclusions, it is suggested that ATM polymorphisms are associated with DRC among PAHs-exposed workers and ATM plays key roles in repair of chromosomal damage and cell cycle control with the treatment of B(a)P.