Worldwide trends in mortality for hypertensive heart disease from 1990 to 2019 with projection to 2034: data from the Global Burden of Disease 2019 study.

AIMS: This study aims to analyse the worldwide trends in hypertensive heart disease (HHD) mortality and associations with age, period, and birth cohort and predict the future burden of HHD deaths. METHODS AND RESULTS: Mortality estimates were obtained from Global Burden of Disease 2019 study. We used age-period-cohort (APC) model to examine the age, period, and cohort effects on HHD mortality between 1990 and 2019. Bayesian APC model was utilized to predict HHD deaths to 2034. The global HHD deaths were 1.16 million in 2019 and were projected to increase to 1.57 million in 2034, with the largest increment in low- and middle-income countries (LMICs). Between 1990 and 2019, middle/high-middle socio-demographic index (SDI) countries had the largest mortality reductions (annual percentage change = -2.06%), whereas low SDI countries saw a lagging performance (annual percentage change = -1.09%). There was a prominent transition in the age distribution of deaths towards old-age population in middle/high-middle SDI countries, while the proportion of premature deaths (aged under 60 years) remained at 24% in low SDI countries in 2019. Amongst LMICs, Brazil, China, and Ethiopia showed typically improving trends both over time and in recent birth cohorts, whereas 63 countries including Indonesia, the Philippines, and Pakistan had unfavourable or worsening risks for recent periods and birth cohorts. CONCLUSION: The HHD death burden in 2019 is vast and is expected to increase rapidly in the next decade, particularly for LMICs. Limited progress in HHD management together with high premature mortality would exact huge human and medical costs in low SDI countries. The examples from Brazil, China, and Ethiopia suggest that efficient health systems with action on improving hypertension care can reduce HHD mortality effectively in LMICs.

This study provides the first comprehensive analysis of the age, period, and cohort trends in mortality for hypertensive heart disease (HHD) across 204 countries and territories from 1990 to 2019, with projection to 2034. The death burden of HHD is substantial and growing rapidly in most of the world, particularly in low- and middle-income countries (LMICs). Wide disparities exist within LMICs in HHD management, with most low socio-demographic index countries showing little progress in reducing HHD mortality. The examples from Brazil, China, and Ethiopia suggest that prevention policies for HHD can reduce risks for younger birth cohorts and shift the risks for all age groups over time.

[Scalp-nape acupuncture as adjuvant therapy for pharyngeal dysphagia of stroke at recovery stage: a randomized controlled trial].

OBJECTIVE: To observe the therapeutic effect of scalp-nape acupuncture for pharyngeal dysphagia of stroke at recovery stage on the basis of neuromuscular electrical stimulation (NMES) and rehabilitation training. METHODS: A total of 42 patients with pharyngeal dysphagia of stroke at recovery stage were randomized into an observation group and a control group, 21 cases in each group. Conventional medical symptomatic treatment was given in both groups. NMES and rehabilitation training were adopted in the control group, 30 min for each one. On the basis of the treatment in the control group, scalp-nape acupuncture was given in the observation group, scalp acupuncture was applied at lower 2/5 of anterior and posterior oblique lines of parietal and temporal, nape acupuncture was applied at Fengchi (GB 20), Yiming (EX-HN 14), Gongxue (Extra), Zhiqiang (Extra), Tunyan (Extra), etc. The treatment was given once a day, 5 days a week for 3 weeks in both groups. Before and after treatment, the videofluoroscopic dysphagia scale (VDS) score, the Kubota water swallowing test grade, the functional oral intake scale (FOIS) grade and the swallowing quality of life (SWAL-QOL) score were observed in both groups. RESULTS: After treatment, the VDS scores were decreased and the SWAL-QOL scores were increased compared before treatment (P<0.05), the Kubota water swallowing test grade and FOIS grade were improved compared before treatment (P<0.05) in both groups. The changes of VDS score and SWAL-QOL score, Kubota water swallowing test grade and FOIS grade in the observation group were superior to those in the control group (P<0.05). CONCLUSION: Based on NMES and rehabilitation training, scalp-nape acupuncture can enhance the therapeutic effect on pharyngeal dysphagia of stroke at recovery stage, and improve the patients' swallowing function and quality of life.

Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial.

Importance: A rapid nutritional transition has caused greater childhood obesity prevalence in many countries, but the repertoire of effective preventive interventions remains limited. Objective: To determine the effectiveness of a novel multifaceted intervention for obesity prevention in primary school children. Design, Setting, and Participants: A cluster randomized clinical trial was conducted during a single school year (from September 11, 2018, to June 30, 2019) across 3 socioeconomically distinct regions in China according to a prespecified trial protocol. Twenty-four schools were randomly allocated (1:1) to the intervention or the control group, with 1392 eligible children aged 8 to 10 years participating. Data from the intent-to-treat population were analyzed from October 1 to December 31, 2019. Interventions: A multifaceted intervention targeted both children (promoting healthy diet and physical activity) and their environment (engaging schools and families to support children's behavioral changes). The intervention was novel in its strengthening of family involvement with the assistance of a smartphone app. The control schools engaged in their usual practices. Main Outcomes and Measures: The primary outcome was the change in body mass index (BMI; calculated as weight in kilograms divided by height in square meters) from baseline to the end of the trial. Secondary outcomes included changes in adiposity outcomes (eg, BMI z score, prevalence of obesity), blood pressure, physical activity and dietary behaviors, obesity-related knowledge, and physical fitness. Generalized linear mixed models were used in the analyses. Results: Among the 1392 participants (mean [SD] age, 9.6 [0.4] years; 717 boys [51.5%]; mean [SD] BMI, 18.6 [3.7]), 1362 (97.8%) with follow-up data were included in the analyses. From baseline to the end of the trial, the mean BMI decreased in the intervention group, whereas it increased in the control group; the mean between-group difference in BMI change was -0.46 (95% CI, -0.67 to -0.25; P < .001), which showed no evidence of difference across different regions, sexes, maternal education levels, and primary caregivers (parents vs nonparents). The prevalence of obesity decreased by 27.0% of the baseline figure (a relative decrease) in the intervention group, compared with 5.6% in the control group. The intervention also improved other adiposity outcomes, dietary, sedentary, and physical activity behaviors, and obesity-related knowledge, but it did not change moderate- to vigorous-intensity physical activity, physical fitness, or blood pressure. No adverse events were observed during the intervention. Conclusions and Relevance: The multifaceted intervention effectively reduced the mean BMI and obesity prevalence in primary school children across socioeconomically distinct regions in China, suggesting its potential for national scaling. Trial Registration: ClinicalTrials.gov Identifier: NCT03665857.

Effect of Conduction Band Non-Parabolicity on the Nonlinear Optical Properties in GaAs/Ga1-xAlxAs Double Semi-V-shaped Quantum Wells.

In this paper, we investigate the effect of conduction band non-parabolicity (NPBE) on the third harmonic generation(THG), the linear and nonlinear intersub-band optical absorption coefficients (OACs) related with electronic states of double semi-V-shaped GaAs/Ga1-xAlxAs quantum wells(QWs) by using the compact-density-matrix approach. Simultaneously, the work is performed in the position dependent effective mass in order to compute the electronic structure for the system by the finite difference and self-consistent techniques. We also compare the results with and without considering NPBE. It is found that: (1) the NPBE has a significant influence on the sub-band energy levels of double semi-V-shaped QWs, and (2) the amplitude and position of the resonant peaks of the THG and nonlinear OACs in the case of considering NPBE show complicated behavior due to the energy dependent effective mass m*(E) where the energy value was chosen self-consistently.

The Combined Influence of Hydrostatic Pressure and Temperature on Nonlinear Optical Properties of GaAs/Ga0.7Al0.3As Morse Quantum Well in the Presence of an Applied Magnetic Field.

Studies aimed at understanding the nonlinear optical (NLO) properties of GaAs/Ga0.7Al0.3As morse quantum well (QW) have focused on the intersubband optical absorption coefficients (OACs) and refractive index changes (RICs). These studies have taken two complimentary approaches: (1) The compact-density-matrix approach and iterative method have been used to obtain the expressions of OACs and RICs in morse QW. (2) Finite difference techniques have been used to obtain energy eigenvalues and their corresponding eigenfunctions of GaAs/Ga0.7Al0.3As morse QW under an applied magnetic field, hydrostatic pressure, and temperature. Our results show that the hydrostatic pressure and magnetic field have a significant influence on the position and the magnitude of the resonant peaks of the nonlinear OACs and RICs. Simultaneously, a saturation case is observed on the total absorption spectrum, which is modulated by the hydrostatic pressure and magnetic field. Physical reasons have been analyzed in depth.

Stable SET knockdown in breast cell carcinoma inhibits cell migration and invasion.

Breast cancer is the most malignant tumor for women, however, the mechanisms underlying this devastating disease remain unclear. SET is an endogenous inhibitor of protein phosphatase 2A (PP2A) and involved in many physiological and pathological processes. SET could promote the occurrence of tumor through inhibiting PP2A. In this study, we explore the role of SET in the migration and invasion of breast cancer cells MDA-MB-231 and ZR-75-30. The stable suppression of SET expression through lentivirus-mediated RNA interference (RNAi) was shown to inhibit the growth, migration and invasion of breast cancer cells. Knockdown of SET increases the activity and expression of PP2Ac and decrease the expression of matrix metalloproteinase 9 (MMP-9). These data demonstrate that SET may be involved in the pathogenic processes of breast cancer, indicating that SET can serve as a potential therapeutic target for the treatment of breast cancer.

Study on the application of Raman spectroscopy on detecting water hardness.

Laser Raman spectrum method was used to study the hardness index of four water samples. The ratio of bending vibration peak intensity to stretching vibration peak intensity of these water samples was measured. The results showed that as the total hardness of water decreases, so does the ratio. This offers a possible new approach to water quality analysis that is both simple and effective.

[Study on sperm damage caused by trichloroethylene in male rats].

OBJECTIVE: To study in vitro sperm damage caused by trichloroethylene in male rats. METHODS: Sperms of Sprague-Dawley (SD) rats were collected 4 hours after being contaminated by trichloroethylene of 0, 2, 4, 6, 8, and 10 mmol/L in vitro. Giemsa staining was performed to observe the morphological changes of sperms, and flow cytometer was used to detect the changes in mitochondrial membrane potential. RESULTS: The sperm motilities in 6, 8, and 10 mmol/L trichloroethylene groups decreased significantly compared with that in control group (P <0.01); the sperm aberration rates in 8 and 10 mmol/L trichloroethylene groups were significantly higher than that in control group (P<0.01). With the increase in exposure dose, the proportion of sperms with reduced mitochondrial membrane potential increased, and there were significant differences in sperm apoptosis rate between the 4, 6, 8, and 10 mmol/L trichloroethylene groups and control group (P<0.01). CONCLUSION: In vitro exposure to trichloroethylene can reduce sperm motility and increase the aberration rate and apoptosis rate of sperms in male SD rats.

Proteome of melamine urinary bladder stones and implication for stone formation.

Melamine can cause urinary stones related to nephropathy of the kidney and hyperplasia or carcinoma of the bladder, but the mechanism of stone formation is not well understood. In this study, male rats were administered melamine for thirteen weeks to establish melamine bladder stone models and the stones were analysed by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS) and western blot, respectively, for the composition and proteome, and to explore the implication of proteins for stone formation. The results showed bladder stones were composed of predominant melamine and a few amount of proteins. The proteins had a wide range of molecular weights and 1051 proteins were identified. Gene Ontology (GO) classification of the identified proteins showed most proteins were from injured cells, involved in various metabolic processes and had binding functions. Of the identified proteins, there were a few inflammatory proteins and urinary proteins. Physicochemical characteristics of the identified proteins showed that 67.1% proteins' isoelectric points (pI) value was below 7.0, 91.1% proteins' grand average of hydropathicity (GRAVY) scores were below 0 and nearly half of the proteins were stable. Our data indicated proteins might play an important role in melamine bladder stone formation.

Chromium(VI) causes down regulation of biotinidase in human bronchial epithelial cells by modifications of histone acetylation.

Hexavalent chromium (Cr(VI)), a commonly used industrial metal, is a well-known mutagen and carcinogen, and occupational exposure can induce a broad spectrum of adverse health effects, including cancers. Although Cr(VI)-induced DNA damage is thought to be the primary mechanism of chromate genotoxicity and mutagenicity, there is an increasing number of reports showing that epigenetic mechanisms of gene regulation might be a central target of Cr(VI) toxicity. Epigenetic changes, such as changes in phosphorylation, altered DNA methylation status, histone acetylation and signaling pathways, have been observed after chromium exposure. Nevertheless, to better demonstrate the roles of epigenetic modifications in Cr(VI)-induced carcinogenesis, more work needs to be carried out. This study is aimed to investigate changes in biotinidase (BTD) and holocarboxylase synthetase (HCS), two major proteins which maintain homeostasis of the newfound epigenetic modification: histone biotinylation, in cells exposed to Cr(VI). The data showed that Cr(VI) decreased BTD expression at the transcriptional level in human bronchial epithelial cells (16HBE). In addition, using the epigenetic modifiers, 5-Aza-2'-deoxycytidine (Aza) and Trichostatin A (TSA), we found that modifications of histone acetylation reversed the inhibition of BTD, suggesting that Cr(VI) may cause down regulation of BTD by modifications of histone acetylation.

[A cell-based detection of ciguatoxin using sodium fluorescence probe].

OBJECTIVE: To establish a cell-based detection method of ciguatoxin using fluorescence assay. METHODS: Mouse neuroblastoma N-2A cells were exposed to ouabain and veratridine and different concentrations of standard ciguatoxin samples (P-CTX-1) to establish the curvilinear relationship between the toxin dosage and fluorescence intensity using the sodium fluorescence probe CoroNaTM Green. The toxicity curvilinear relationship was also generated between the toxin dosage and cell survival using CCK-8 method. Based on these standard curves, the presence of ciguatoxin was detected in 33 samples of deep-sea coral fish. RESULTS: A correlation was found between the detection results of cell-based fluorescence assay and cytotoxicity assay, whose detection limit reached 103 g/ml and 1012 g/ml, respectively. The cell-based fluorescent assay sensitivity showed a higher sensitivity than cytotoxicity assay with a 2-4 h reduction of the detection time. CONCLUSIONS: The cell-based fluorescent assay can quickly and sensitively detect ciguatoxin and may serve as a good option for preliminary screening of the toxin.

[Study on mRNA expression of immune-related genes in patients with allergic dermatitis induced by trichloroethylene].

OBJECTIVE: To study mRNA expression of immune-related genes (Foxp3, GATA3, CTLA4 and T-bet) in peripheral blood of the patients with allergic dermatitis induced by trichloroethylene (TCE). METHODS: The peripheral blood samples were collected from 8 healthy workers (control group) and 8 patients with allergic dermatitis induced by TCE (case group). Real-time quantitative PCR was applied to detect mRNA expression of immune-related genes (Foxp3, GATA3, CTLA4, T-bet). RESULTS: The mRNA expression levels of Foxp3, GATA3 and CTLA4 genes increased by 115%, 97% and 241% in case group, as compared with control group (P < 0.01). The mRNA expression level of T-bet gene decreased by 47% in case group, as compared with control group (P < 0.01). CONCLUSION: The mRNA expression levels of some immune-related genes changed in patients with allergic dermatitis induced by TCE, those genes may play an important role in TCE-induced allergy.

[Association of cooking oil fumes exposure and oxidative DNA damage among occupational exposed populations].

BACKGROUND: Previous investigations indicate that cooks are exposed to polycyclic aromatic hydrocarbons (PAH) from cooking oil fumes (COF). However, Emission of PAH and their carcinogenic potencies from cooking oil fumes sources have not been investigated among cooks. AIMS: To investigate the urinary excretion of a marker for oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OHdG), in different groups of cooks and different exposure groups, and to study the association between 8-OHdG and 1-hydroxypyrene (1-OHP), a biological marker for PAH exposure. METHODS: Urine samples were collected from different groups of cooks (n = 86) and from unexposed controls (n = 36), all are male with similar age and smoking habits. The health status, occupational history, smoking, and alcohol consumption 24 hours prior to sampling was estimated from questionnaires. The urinary samples were frozen for later analyses of 8-OHdG and 1-OHP by high performance liquid chromatography. RESULTS: Excretion in urine of 8-OHdG were similar for controls (mean 1.2 µmol/mol creatinine, n = 36), and for those who had been in the kitchen room with exhaust hood operation (mean 1.5 µmol/mol creatinine, n = 45). COF exposed cooks without exhaust hood operation had increased excretion of 8-OHdG (mean 2.3 µmol/mol creatinine, n = 18). The difference between this group and the unexposed controls was significant. The urinary levels of ln 1-OHP and ln 8-OHdG were still significantly correlated in a multiple regression analysis. CONCLUSION: Results indicate that exposure to PAH or possibly other compounds in COF may cause oxidative DNA damage.

[Screening and identification of differential serum proteins related to dermatitis medicamentosa-like of trichloroethylene].

OBJECTIVE: To screen and identify differential serum proteins which might be involved in dermatitis medicamentosa-like of trichloroethylene (DMLT). METHODS: Three groups of sera were collected from population exposed to trichloroethylene (TCE) (group I), patients suffering from DMLT (group II), and the healed cases (group III). After removing albumin and IgG in the three pools of sera, a comparative proteomic analysis was carried out. The images were analyzed using ImageMaster Platinum 2D 5.0 to screen the differentially expressed proteins. The protein spots were then subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry sequencing of tryptic peptides for further identification. RESULTS: The depletion of albumin and IgG greatly increased the number of protein spots to 300 ± 12.Five differential spots were identified, which were complement component C4b, apolipoprotein A-I, apolipoprotein C-III apolipoprotein C-II and transthyretin. Compared with group I, the expression levels of complement component C4b in group III and apolipoprotein C-II in group II were up-regulated (1.352 88-fold, 1.512 14-fold, respectively); compared with group I, the expression levels of apolipoprotein A-I, apolipoprotein C-III and transthyretin in group II were down-regulated (1.601 17-fold, 1.034 49-fold, 1.313 35-fold, respectively). CONCLUSION: The findings of this study show that most of the identified differential proteins are closely related to immunity and liver dysfunction, which provides some evidence on elucidating the mechanisms and screening of biomarkers of TCE intoxication.

[Construction of a eukaryotic expression vector harboring the small interfering RNA targeting HCMV-IE1 gene and its gene silencing efficiency].

OBJECTIVE: To investigate the effect of RNA interference targeting human cytomegalovirus immediate early gene 1 (HCMV- IE1) on the gene expression in vitro. METHODS: According to the sequence of HCMV-IE1 gene, the small interfering RNA (siRNA) sequences were designed and introduced into the eukaryotic expression vector containing the U6 promoter. After verification by sequence analysis, the recombinant eukaryotic plasmid (pHCMV-IE1i) was transfected into HEL HCMVAD169 cells. The effectiveness of HCMV-IE1 gene silencing was investigated by fluorescence microscopy, flow cytometry and RT-PCR. RESULTS: Sequence analysis confirmed successful construction of the recombinant eukaryotic expression plasmid pHCMV-IE1i. The expression of HCMV-IE1 was effectively suppressed by pHCMV-IE1i transfection in HEL cells as shown by fluorescence microscopy, flow cytometry (P < 0.05) and RT-PCR (P < 0.05). CONCLUSION: The expression of HCMV-IE1 can be effectively suppressed by RNA interference technique in vitro, which provides experimental data for prevention and treatment of HCMV infection.

[Effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase in normal rat kidney epithelial cells].

OBJECTIVE: To explore the effect of cadmium chloride on the expression and phosphorylation of mitogen-activated protein kinase (MAPK) in normal rat kidney epithelial (NRK) cells. METHODS: The NRK cells were incubated with cadmium chloride either at respective dose (0, 1, 5, 10, 20, 40 µmol/L) for 24 h or at same dose (10 µmol/L) for respective time (0, 0.5, 1.0, 2.0, 4.0, 8.0 h). Western blotting was applied to test the expression of MAPK in NRK cells (ERK1/2, p38, JNK); and phosphor-specific antibody to detect the phosphorylated MAPK (p-ERK1/2, p-p38, p-JNK). RESULTS: There was no significant difference in the MAPK expression among the groups either treated with different doses or for different time; however, the level of phosphorylated MAPK was comparatively higher than it in control group. There was an obvious expression of p-ERK1/2 at 1.00 ± 0.06 in the group incubated with 10 µmol/L CdCl(2); and the expression in the 20 µmol/L and 40 µmol/L CdCl(2) group was 2.58 ± 0.11, 2.76 ± 0.23 respectively, which was 1.58 and 1.76 times more than it in 10 µmol/L CdCl(2) group. The differences were statistically significant (F = 827.70, P < 0.01). The respective expression of p-p38MAPK in the 20 µmol/L (2.47 ± 0.20)and 40 µmol/L CdCl(2) group (3.73 ± 0.25)was 1.47 and 2.73 times more than it in control group (1.00 ± 0.02), and the differences were also statistically significant (F = 280.06, P < 0.01). There was a dose-effect relationship of the concentration of cadmium in the expression of p-ERK1/2 (r = 0.919, t = 4.69, P = 0.009) and p-p38MAPK (r = 0.945, t = 5.79, P = 0.004). Additionally, phosphorylated MAPK expressed in a time-dependent manner. The expression of p-ERK1/2 was obvious in the group incubated for 1 h (1.26 ± 0.11), and the respective expression in the 4 h group (1.51 ± 0.07) and 8 h group (3.53 ± 0.23) was 1.5 and 3.5 times of it in the control group (1.00 ± 0.02). The differences were statistically significant (F = 427.82, P < 0.001). The expression of p-p38MAPK increased significantly in 1 h group (1.31 ± 0.07); while the respective expression in 4 h group (3.53 ± 0.32) and 8 h group (4.41 ± 0.38) was 3.5 and 4.4 times of it in control group (1.00 ± 0.03). The differences were also statistically significant (F = 280.06, P < 0.001). CONCLUSION: Cadmium chloride could significantly enhance the phosphorylation of MAPK in NRK cells; and it is probably associated with the activation of MAPK.

[Effect of hydroquinone on expression of ubiquitin-ligating enzyme Rad18 in human L-02 hepatic cells].

OBJECTIVE: To investigate the effects of hydroquinone (HQ) on expression of ubiquitin-ligating enzyme Rad18 in human hepatic cells (L-02), and to explore the role and possible mechanism of Rad18 involved in toxicity of HQ to hepatic cells. METHODS: After L-02 hepatic cells were exposed to HQ with various concentrations (0, 5, 10, 20, 40, 80 and 160 micromol/L) for 24 h, cell survival rate was measured by MTT assay; DNA impairment was evaluated by single cell gel electrophoresis (SCGE); The expression levels of Rad18 mRNA and protein were detected by Real-time fluorescent quantitative polymerase chain reaction (QPCR) technique and Western blot method respectively. RESULTS: HQ with concentration from 0 to 80 micromol/L had little effect on survival rate of L-02 (P > 0.05); Whereas the survival rate in the group of 160 micromol/L was significantly lower than in the control with the significant difference (P < 0.01) after treated with HQ for 24 h; The higher dose of HQ presented, the more degrees of olive tail moment (OTM) were produced and a dose-dependent relationship was shown. HQ in a low concentration (0 to approximately 40 micromol/L) could induce increase in the expression of Rad18 mRNA and protein which was in proportion to the increment of HQ concentration; the expression of Rad18 mRNA was enhanced increasingly, while the expression of Rad18 protein unchanged basically once the concentration of HQ exceeded 40 micromol/L; Besides, there was a positive correlation between OTM and the expression level of Rad18 mRNA (r = 0.919, P < 0.01). CONCLUSION: HQ could regulate up the expression of Rad18 in L-02 hepatic cells.

Effect of PARP-1 deficiency on DNA damage and repair in human bronchial epithelial cells exposed to Benzo(a)pyrene.

Benzo[a]pyrene is a ubiquitously distributed environmental pollutant known to cause DNA damage, whereas PARP-1 is a nuclear enzyme that is activated by damaged DNA and plays an important role in base excision repair and genomic stability. Here, 16HBE and its PAPR1-deficient cells were exposed to BaP, and the DNA damage level and repair ability of both cell lines were measured by alkaline comet assay. The results showed that cell viability of both cell lines decreased in a dose-dependent manner when exposed to BaP, but there was no significant difference between two cell lines. Comet assay showed that BaP caused DNA damage in both cell lines at an obvious dose- and time-dependent manner. Compare with 16HBE, the PARP1-deficient cells were more sensitive to the damage caused by BaP. The results of DNA repair experiment showed that both cell lines can recover from the damage in a time-dependent pattern. The relative repair percentage of PARP1-deficient cells were generally lower than that of 16HBE at all exposed concentrations at the early stage of repair, but tended to be closer between two cell lines at the later period. According to results, we came to the conclusion that PARP1-deficient cells were more sensitive to BaP in contrast to normal 16HBE; DNA repair capacity in PARP1-deficient cells decreased significantly at the early stage of repair, but increased to the equivalent level of normal 16HBE in the later period. PARP-1 plays an important role in early repair of DNA damage caused by BaP in 16HBE notwithstanding the main repair work is taken by NER pathway.

An investigation of hormesis of trichloroethylene in L-02 liver cells by differential proteomic analysis.

Hormesis is the dose-response pattern of the biological responses to toxic chemicals, characterized by low-dose stimulation and high-dose inhibition. Although it is known that some cell types exhibit an adaptive response to low levels of cytotoxic agents, its molecular mechanism is still unclear and it has yet to be established whether this is a universal phenomenon that occurs in all cell types in response to exposure to every chemical. Trichloroethylene (TCE) is an organic solvent widely used and is released into the atmosphere from industrial degreasing operations. Acute (short-term) and chronic (long-term) inhalation exposure to trichloroethylene can affect the human health. In order to elucidate a cell-survival adaptive response of L-02 liver cells exposed to low dose of TCE, CCK-8 assay was used to assess cytotoxicity, and examined the possible mechanisms of hormesis by proteomics technology. We found that exposure of L-02 liver cells to low level of TCE resulted in adaptation to further exposure to higher level, about 1,000 protein-spots were obtained by two-dimensional electrophoresis (2-DE) and five protein spots were identified by matrix-assisted laser desorption/ionization mass spectrometry and tandem mass spectrometry sequencing of tryptic peptides. Our results suggest that a relationship may exist between identified proteins and TCE-induced hormesis, which are very useful for further study of the mechanism and risk assessment of TCE.

[Study on the relationship between breast cancer resistance protein expression and 5-fluorouracil resistance].

OBJECTIVE: To screen breast cancer resistance protein BCRP-mediated resistance agents and to investigate the relations between BCRP expression and drug resistance. METHODS: MT assay was performed to screen BCRP-mediated resistant agents with established BCRP expression cell model. While, the high performance liquid chromatography (HPLC) assay was administrated to measure the related dosage of intracellular retention resistant agents. The BCRP expression was investigated by both real-time RT-PCR and immunohistochemistry (IHC) assay in 140 clinical breast cancer tissue specimens. Chemosensitivity to resistant agents for clinical breast cancer tissue specimens was analyzed by MT assay. The Nonparametric variance statistics method was used to analyze the correlations between clinical breast cancer tissue of BCRP expression and drug resistance. RESULTS: MT assay showed that increasing resistance of 5-fluorouracil (5-Fu) climbed with the increases of the BCRP expressions by 10.58 times (P < 0.05, n = 3) in cell model. HPLC assay also proved that a significant negative correlation between the intracellular retention dose of 5-Fu with different expression of BCRP (r = -0.897, P < 0.05, n = 3). Forty-seven tissue specimens of BCRP-positive expression were rapidly determined by using both real-time RT-PCR and IHC in 140 clinical breast cancer tissue specimens. Subsequently, the resistance index (RI) for 47 BCRP-positive clinical breast cancer tissues to 5-Fu was shown from 7 to 12 times compared with normal cancer-side tissues through MT assay. The statistical correlation between BCRP expression and 5-Fu resistance was observed in clinical breast cancer tissue specimens (R2 = 0.8124, P < 0.01). CONCLUSION: This study results showed that there is a significant relationship between BCRP expression and 5-Fu resistance. Moreover, the results suggest that the chemotherapy scheme could be optimized on BCRP-positive expression breast cancer patients.