Concurrent Hearing and Genetic Screening of 180,469 Neonates with Follow-up in Beijing, China.

Concurrent hearing and genetic screening of newborns is expected to play important roles not only in early detection and diagnosis of congenital deafness, which triggers intervention, but also in predicting late-onset and progressive hearing loss and identifying individuals who are at risk of drug-induced HL. Concurrent hearing and genetic screening in the whole newborn population in Beijing was launched in January 2012. This study included 180,469 infants born in Beijing between April 2013 and March 2014, with last follow-up on February 24, 2018. Hearing screening was performed using transiently evoked otoacoustic emission (TEOAE) and automated auditory brainstem response (AABR). For genetic testing, dried blood spots were collected and nine variants in four genes, GJB2, SLC26A4, mtDNA 12S rRNA, and GJB3, were screened using a DNA microarray platform. Of the 180,469 infants, 1,915 (1.061%) were referred bilaterally or unilaterally for hearing screening; 8,136 (4.508%) were positive for genetic screening (heterozygote, homozygote, or compound heterozygote and mtDNA homoplasmy or heteroplasmy), among whom 7,896 (4.375%) passed hearing screening. Forty (0.022%) infants carried two variants in GJB2 or SLC26A4 (homozygote or compound heterozygote) and 10 of those infants passed newborn hearing screening. In total, 409 (0.227%) infants carried the mtDNA 12S rRNA variant (m.1555A>G or m.1494C>T), and 405 of them passed newborn hearing screening. In this cohort study, 25% of infants with pathogenic combinations of GJB2 or SLC26A4 variants and 99% of infants with an m.1555A>G or m.1494C>T variant passed routine newborn hearing screening, indicating that concurrent screening provides a more comprehensive approach for management of congenital deafness and prevention of ototoxicity.

A Five-year Surveillance of Carbapenemase-producing Klebsiella pneumoniae in a Pediatric Hospital in China Reveals Increased Predominance of NDM-1.

OBJECTIVE: To characterize carbapenem (CPM)-non-susceptible Klebsiella pneumoniae (K. pneumoniae) and carbape-nemase produced by these strains isolated from Beijing Children's Hospital based on a five-year surveillance. METHODS: The Minimal Inhibition Concentration values for 15 antibiotics were assessed using the Phonix100 compact system. PCR amplification and DNA sequencing were used to detect genes encoding carbapenemases. WHONET 5.6 was finally used for resistance analysis. RESULTS: In total, 179 strains of CPM-non-susceptible K. pneumoniae were isolated from January, 2010 to December, 2014. The rates of non-susceptible to imipenem and meropenem were 95.0% and 95.6%, respectively. In the 179 strains, 95 (53.1%) strains carried the blaIMP gene, and IMP-4 and IMP-8 were detected in 92 (96.8%) and 3 (3.2%) IMP-producing isolates, respectively. 65 (36.3%) strains carried the blaNDM-1 gene. 6 (3.4%) strains carried the blaKPC gene, and KPC-2 were detected in 6 KPC-producing isolates. In addition, New Delhi-Metallo-1 (NDM-1) producing isolates increased from 7.1% to 63.0% in five years and IMP-4 producing isolates decreased from 75.0% to 28.3%. CONCLUSION: High frequencies of multiple resistances to antibiotics were observed in the CPM-non-susceptible K. pneumoniae strains isolated from Beijing Children's Hospital. The production of IMP-4 and NDM-1 metallo-ß-lactamases appears to be an important mechanism for CPM-non- susceptible in K. pneumoniae.

MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

[Relationship of alcohol drinking and tea consumption with the risk of nasopharynx cancer among Chinese population: a meta-analysis].

OBJECTIVE: To evaluate the relationship and strength of association for alcohol drinking and tea consumption with the riskS of nasopharynx cancer among Chinese population so as to provide control rationales for nasopharynx cancer in China. METHODS: A systematic search of 3 Chinese electronic databases (CNKI, VIP, Wanfang) and 3 English databases (Pubmed, ScienceDirect and SpringerLink) up to March 2013 was performed. Two reviewers independently conducted the literature search, examined eligibility and performed data extraction and quality evaluations. Pooled odd ratio (OR) value and 95%CI value were calculated with random-effects model weighted with inverse of variances. RESULTS: A total of 14 studies (including 3 cohort and 11 case-control) involving 6559 cases of nasopharynx cancer and 10 567 controls from 6 provinces were included. The pooled OR between alcohol drinking and risks of nasopharynx cancer was 1.12 (95%CI: 0.98-1.26; I(2) = 44.5%, P = 0.037). Compared with the non-drinkers, the risks of nasopharynx cancer for regular drinkers and occasional drinkers were 1.18 (95%CI: 1.00-1.38; I(2) = 0.0%, P = 0.578) and 0.76 (95%CI: 0.65-0.89; I(2) = 33.4%, P = 0.212). And the association of tea consumption with the risks of nasopharynx cancer was 0.53 (95%CI: 0.43-0.60; I(2) = 17.9%, P = 0.301). CONCLUSIONS: In China, occasional alcohol drinking may decrease the risks of nasopharynx cancer while regular drinking elevates the risks. And there is significantly protective effect for tea consumption on the risks of nasopharynx cancer.

[Functional Bax polymorphism associated with lung cancer susceptibility].

OBJECTIVE: The Bcl-2 associated X protein (Bax), belonging to the Bcl-2 family, plays a pivotal role in mitochondria-dependent apoptosis. The aims of this study are to revalidate the functional significance of Bax G(-248)A polymorphism, and investigate its association with lung cancer risk in Chinese population. METHODS: The biological function of Bax G(-248)A was tested by luciferase assays, and its effects on lung cancer risk was determined by case-control analysis of 989 patients with lung cancer and 990 controls. RESULTS: Bax -248A allele exhibited significantly higher transcriptional activity compared with G allele. The Bax-248A allele carriers yielded a significantly decreased risk of lung cancer, compared with -248G allele carriers (OR = 0.68, 95% CI = 0.48 approximately 0.90, P = 0.01). Furthermore, a significant gene-smoking interaction between Bax G(-248)A polymorphism and smoking existed among the light smokers. CONCLUSION: Bax G(-248)A polymorphism is associated with lung cancer susceptibility in Chinese population.

[Chemical Characteristics of Groundwater and Material Sources Analysis in Shiqi River Basin].

To investigate the chemical characteristics of groundwater and material sources in a typical karst hill (valley) depression, 41 groundwater samples were systematically collected in the Shiqi River basin. The statistical analysis of the conventional ion content in the groundwater shows that pH of the groundwater in the study area is between 6.06-8.07, the total solid solubility is between 18.21 mg ·L-1 and 336.28 mg ·L-1, and the charges of anions and cations in the water body are balanced. Ca2+, Mg2+, and HCO3- are the main ions in groundwater, with concentrations of 2.61-108.7 mg ·L-1, 0.54-27.61 mg ·L-1, and 8.1-370.74 mg ·L-1, respectively. The groundwater characteristics in the study area are consistent with the high calcium and weak alkalinity characteristics of karst water. By using the Gibbs diagram, piper diagram, end-member analysis, and ion proportional coefficient, hydrochemical characteristics and material sources of groundwater were further analyzed. The results show that Ca2+ and Mg2+ are mainly controlled by the weathering of limestone and dolomite in which carbonic acid is involved. Na+ mainly comes from the dissolution of silicate rocks. At the same time, Ca2+ and Na+ undergo cationic exchange adsorption in the groundwater flow process. K+, Cl-, and NO3- are mainly affected by agricultural fertilizer application and domestic wastewater discharge. The hydrogen and oxygen isotope analysis of groundwater shows that atmospheric precipitation is the main recharge source of groundwater in this region, which impacts the chemical characteristics and material sources of local groundwater. The results of this study show that the geological background of groundwater is the main factor that affects its hydrochemical characteristics and material sources in areas with relatively little anthropogenic activity.

[Identifying Nitrate Sources in a Typical Karst Underground River Basin].

Underground rivers are an important source of groundwater in karst area. Recently, nitrate pollution of underground rivers has become a serious issue. To identify the sources of nitrate in Guancun typical karst underground river basin, stable isotope techniques (δ15N-NO3-, δ18O-NO3-, and δ18O-H2O) were applied in this study. The contribution rates of different nitrate sources in groundwater were quantitatively identified based on the stable isotope analysis in R (SIAR) model, and the influence of land use type on nitrate distribution and source in watershed water was clarified. The results showed that ① nitrate mainly came from fertilizers, soil organic nitrogen, and manure/sewage based to the isotopic composition of nitrate nitrogen and oxygen isotopes. It was revealed that non-point sources significantly contributed to nitrate in waters of the Guancun underground river basin. ② Nitrification dominated the formation process of nitrate in groundwater, and the initial values of nitrogen and oxygen isotopes were not affected by fractionation. ③ Based on SIAR, the contribution of different sources to nitrate in water in the basin varied seasonally, and the contributions of fertilizer, soil organic nitrogen, and manure/sewage to nitrate were 57.07%, 34.06%, and 8.87% in the wet season and 34.14%, 33.02%, and 32.84% in the dry season, respectively. Overall, the present study quantitatively evaluated the temporal variations of nitrate sources in a typical karst groundwater river basin and provided a theoretical foundation for prevention and control management of non-point source pollution and watershed management in karst areas.

[Biogeochemical Characteristics in Shengli Site of Lijiang River Under the High Resolution Monitoring].

This study was done to understand the diel variation and factors influencing the hydrochemistry of the Lijing River in different seasons. This is a typical medium river located at Guilin City in the Guangxi Zhuang Autonomous Region, SW China. The Shengli site was selected for this study. Two-day monitoring work with a high resolution rate logger and high frequency sampling at 2 hour intervals was conducted at the Shengli site of the Lijiang River in summer and autumn separately. Physical and hydrogeochemical parameters including pH, dissolved oxygen (DO), water temperature (T), electrical conductivity (EC), dissolved inorganic carbon (DIC), isotopes, and other chemical parameters were examined. The results show that:① the physical and hydrochemical parameters[T, pH, DO, SIC, EC, p (CO2)] and major ions (HCO3-, Ca2+) at the Shengli site displayed regular diel variation during monitoring. The data for T, pH, DO, and SIC increased in daylight and decreased at night, while the data for Ca2+, HCO3-, EC, and p (CO2) decreased in daylight and increased at night. ② The diurnal changes of nutrient elements (SO42-, NO3-, Cl-, Na+, Mg2+, and K+) at the Shengli site were mainly controlled by photosynthesis and respiration of aquatic plants, and showed the trend of decrease in daylight and increase at night. Due to the influence of a flood in mid-August 2017, the amount of diurnal variation in the nutrient element levels in summer was less than that in autumn. ③ The δ13CDIC increased in daylight and decreased at night both in summer and autumn, reflecting the influences of photosynthesis and precipitation. Under the influence of different root systems, soil microbial respiration intensity, and seasonal variation of river hydrological factors, the δ13CDIC in summer was generally lighter than that in autumn, with average values of -10.08‰ and -8.90‰, respectively. ④ The daily average fixation amount of karst carbon sink caused by aquatic plants was calculated to be 2.12 mmol·L-1 and 0.94 mmol·L-1 for Autumn and Summer, respectively. To sum up, there is a higher efficiency of karst carbon sink caused by aquatic plants in Autumn than that in Summer.

[Genetic polymorphism in MDM2 is associated with susceptibility to colorectal cancer in a Chinese population].

OBJECTIVE: The tumor suppressor p53 pathway plays a crucial role in preventing carcinogenesis through its ability to impose cell cycle arrest and apoptosis following DNA damage or oncogene activation. Mouse double minute 2 (MDM2) gene is a key negative regulator of p53 pathway and overexpressed in many cancers as oncoprotein. We have previously shown that genetic polymorphisms in the MDM2 promoter (309T --> G) and p53 coding region (72Arg --> Pro) are associated with susceptibility to esophageal and lung cancers. This study investigated the associations between these polymorphisms in p53 and MDM2 and risk of the occurrence and progression of colorectal cancer. METHODS: Genotypes of 1000 Chinese colorectal cancer patients and 1300 controls were determined by PCR-based restriction fragment length polymorphism or tetra-primer amplification refractory mutation system-PCR. Associations with risk of colorectal cancer were estimated by unconditional logistic regression. RESULTS: An increased colorectal cancer risk associated with the MDM2 GG [odds ratio (OR) = 2.06, 95% confidence interval (CI) = 1.62-2.62] or TG (OR = 1.31, 95% CI = 1.06-1.62) genotype was observed compared with the TT genotype. No association was found between p53 polymorphism and risk of the cancer, with the ORs being 0.87 (95% CI = 0.68-1.11) for the Pro/Pro and 0. 85 (95% CI = 0.70-1.04) for the Arg/Pro genotype compared with the Arg/Arg genotype. However, combined analysis of MDM2 and p53 polymorphisms showed that compared with subjects carrying both MDM2 TT and p53 Arg/Arg genotypes, the OR for subjects carrying both MDM2 GG and p53 Pro/Pro genotypes was 2.75 (95% CI = 1.60-4.70), significantly higher than that for subjects carrying both MDM2 TT and p53 Pro/Pro genotypes (OR = 1.09, 95% CI = 0.63-1.88). CONCLUSION: These results suggest that genetic polymorphism in MDM2 may be associated with susceptibility to colorectal cancer in a Chinese population.

Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside.

Nucleoside phosphorylases (NPases) were found to be induced in Enterobacter aerogenes DGO-04, and cytidine and cytidine 5'-monophosphate (CMP) were the best inducers. Five mmol/L to fifteen mmol/L cytidine or CMP could distinctly increase the activities of purine nucleoside phosphorylase (PNPase), uridine phosphorylase (UPase) and thymidine phosphorylase (TPase) when they were added into medium from 0 to 8 h. In the process of enzymatic synthesis of adenine arabinoside from adenine and uracil arabinoside with wet cells of Enterobacter aerogenes DGO-04 induced by cytidine or CMP, the reaction time could be shortened from 36 to 6 h. After enzymatic reaction the activity of NPase in the cells induced remained higher than that in the cells uninduced.

[Association between single nucleotide polymorphisms in the promoter of cyclooxygenase COX-2 gene and hereditary susceptibility to pancreatic cancer].

OBJECTIVE: To evaluate the effects of -1290A > G, -1195G > A and -765G > C single nucleotide polymorphisms (SNPs) in the promoter of cyclooxygenase (COX)-2 gene on the risk of pathogenesis of pancreatic cancer. METHODS: Peripheral blood samples were collected from 283 patients with pancreatic cancer and 566 normal controls. Questionnaire survey was conducted to understand the demographic data and status of smoking and smoking cessation of the subjects. Polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) was used to detect the genotypes of the gene fragments containing the 3 SNP sites in the promoter regions of the COX-2 gene. Statistical tests were performed to analyze the relations among different factors and the risk of pancreatic cancer. RESULTS: Three SNPs, -1290A > G, -1195G > A, and -765G > C were identified. A case-control analysis revealed 1.75-fold (95% CI = 1.16-2.64) and 2.53-fold (95% CI = 1.43-4.47) excesses of risks of developing pancreatic cancer for the -1195AA and -765CG genotype carriers respectively compared with the non-carriers. Compared with A(-1290)-G(-1195)-G(-765) containing haplotype, greater risks of developing pancreatic cancer were observed for A(-1290)-A(-1195)-G(-765), (OR = 1.26, 95%, CI = 1.02-1.56) and G(-1290)-A(-1195)-C(-765) (OR = 5.54, 95% CI = 1.79-17.16) containing haplotypes. There were interactions between the -765CG or -1195AA genotype and smoking in the risk of developing pancreatic cancer. CONCLUSION: The SNP of -1195A > G and -765G > C in the COX -2 promoter may play an important role in mediating hereditary susceptibility to developing pancreatic cancer.

Low Bacterial Co-infection Invalidates the Early Use of Non-anti-Mycoplasma pneumoniae Antibiotics in Pediatric Refractory Mycoplasma pneumoniae Pneumonia Patients.

Background: Childhood refractory mycoplasma pneumoniae (MP) pneumonia (RMPP) is a lung disease with elevated level of C-reactive protein and severe clinical and radiological deterioration. Whether bacterial co-infection contributes to disease of RMPP and whether inclusion of non-anti-MP antibiotics in treatment regimen would benefit RMPP patients remains elusive. Methods: We retrospectively reviewed the medical records of 675 RMPP children. Traditional bacterial culture and next generation sequencing (NGS) were used to detect bacteria in bronchoalveolar lavage fluid in all the 675 patients and 18 patients respectively. Antibiotics used and clinical outcomes were analyzed along with other clinical measurements. Results: Positive bacterial cultures were only found in 18 out of 675 cases (2.67%) and NGS analyses of another 18 cases did not revealed positive bacterial infection, which were consistent with the results of bacterial cultures. Non-anti-MP antibiotics were utilized in 630 cases (93.33%), even last-line antibiotics, such as glycopeptides or carbapenems, were frequently used. Conclusion: Bacterial co-infection in RMPP was rare and non-anti-MP antibiotics didn't show any efficacy for early treatment of RMPP patients, which may provide a rationale for restricting the use of non-anti-MP antibiotics in RMPP patients and preventing antibiotic resistance globally.

[Association between genetic polymorphism in xeroderma pigmentosum G gene and risks of laryngeal and hypopharyngeal carcinomas].

OBJECTIVE: To study the association between polymorphism of DNA repair gene xeroderma pigmentosum G (XPG) Asp1104His and the risks of developing laryngeal and hypopharyngeal carcinomas. METHODS: Totally 175 patients with laryngeal or hypopharyngeal carcinoma and 525 cancer-free controls were genotyped for the polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model. RESULTS: Compared with those having the Asp/Asp genotype, patients having the XPG 1104Asp/His genotype had a higher risk for laryngeal carcinoma (OR = 2.46, 95% CI = 1.15-5.24, P < 0.05), but not for hypopharyngeal carcinoma (OR = 1.36, 95% CI = 0.87-2.12, P > 0.05). In addition, the XPG 1104Asp/His genotype appeared to be associated with well differentiated squamous cell carcinoma in both larynx and hypopharynx (OR = 1.88, 95% CI = 1.05-3.40, P < 0.05 ). CONCLUSION: The XPG Asp1104His polymorphism may play a role in the development of laryngeal and hypopharyngeal carcinomas.

[Genetic polymorphisms in the promoter region of cyclooxygenase-2 and their association with risk of gastric cancer].

OBJECTIVE: To examine the genetic polymorphisms in the promoter region of cyclooxygenase-2 ( COX-2) and evaluate their association with the risk of gastric cancer. METHODS: Single-strand conformational polymorphism and DNA sequencing were used to screen the genetic variants of the COX-2 promoter region. Total 323 patients with gastric cancer and 646 frequency-matched controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism method. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Haplotype frequency was estimated using Haplo. stat software. RESULTS: Three single nucleotide polymorphisms, including - 1290A > G, -1195G > A, and -765G > C were identified in the promoter of COX- 2. Case-control analysis showed an increased risk of developing gastric cancer for the -1290AG (OR 1.64; 95% CI 1.03-2.61), -1195AA (OR 2.68; 95% CI 1.65-4.33), and -765CG (OR 2.66; 95% CI 1.53-4.64) genotype carriers, respectively, compared with noncarriers. A greater risk of developing gastric cancer was observed for the A(-1290) -A(-1195) -C(-765) haplotype compared with the A(-1290) -G(-1195) -G(-765) haplotypes (OR 11.80; 95% CI 2.43-57.25). CONCLUSION: Genetic polymorphisms in COX-2 promoter region may play a role in gastric carcinogenesis.

Pneumomediastinum Secondary to Foreign Body Aspiration: Clinical Features and Treatment Explorement in 39 Pediatric Patients.

BACKGROUND: Pneumomediastinum (PM) secondary to foreign body aspiration (FBA) is rare in children. Although it is mainly benign, some cases may be fatal. Due to the rare nature of this clinical entity, proper assessment and management have been poorly studied so far. Here, we characterized the presentation and management of this clinical entity and provided an evaluation system for the management. METHODS: We retrospectively reviewed children with PM secondary to FBA, who were treated in Beijing Children's Hospital from January 2010 to December 2015. All patients were stratified according to the degree of dyspnea on admission, and interventions were given accordingly. Bronchoscopic removals of airway foreign bodies (FBs) were performed on all patients. For patients in acute respiratory distress, emergent air evacuation and/or resuscitations were performed first. Admission data, interventions, and clinical outcomes were recorded. RESULTS: A total of 39 patients were included in this study. The clinical severity was divided into three grades (Grades I, II, and III) according to the degree of dyspnea. Thirty-one patients were in Grade I dyspnea, and they simply underwent bronchoscopic FBs removals. PM resolved spontaneously and all patients recovered uneventfully. Six patients were in Grade II dyspnea, and emergent drainage preceded rigid bronchoscopy. They all recovered uneventfully under close observation. Two exhausted patients were in Grade III dyspnea. They died from large PM and bilateral pneumothorax, respectively, despite of aggressive interventions in our hospital. CONCLUSIONS: PM secondary to FBA could be life-threatening in some patients. The degree of dyspnea should be evaluated immediately, and patients in different dyspnea should be treated accordingly. For patients in Grade I dyspnea, simple bronchoscopic FBs removals could promise a good outcome. For patients in Grade II dyspnea, emergent air evacuation and/or resuscitation should precede a bronchoscopy before the children become exhausted.

[Genetic polymorphisms of apoptosis-associated genes FAS and FASL and risk of colorectal cancer].

OBJECTIVE: The FAS and FASL system plays a key role in regulating apoptotic cell death and corruption of this signaling pathway has been shown to participate in tumorigenesis. We previously have shown that the FAS-1377G/A and FASL-844T/C polymorphisms are associated with esophageal cancer. This case-control study was to examine the contribution of the polymorphisms to susceptibility of colorectal cancer. METHODS: PCR-RFLP method was used to determine the genotypes of FAS-1377G/A and FASL-844T/C in 382 patients with colorectal cancer and 648 controls. The adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression model. RESULTS: The subjects with the AA genotype of FAS-1377G/A and CC genotype of FASL-844T/C had an increased risk for colorectal cancer compared with those with the FAS-1377GG genotype (adjusted OR, 1.65; 95% CI, 1.14-2.38) and FASL-844TT genotype (adjusted OR, 1.76; 95% CI, 1.37-2.28). Furthermore, the effect of FAS and FASL polymorphisms on risk of colorectal cancer displayed a significantly gene-gene interaction (likelihood ratio test, P = 0.002). CONCLUSION: These findings suggest that the FAS-1377G/A and FASL-844T/C polymorphisms may be genetic susceptibility factors for colorectal cancer among Chinese population.

Drug resistance effects of ribosomal protein L24 overexpression in hepatocellular carcinoma HepG2 cells.

BACKGROUND: The morbidity and mortality rate of liver cancer continues to rise in China and advanced cases respond poorly to chemotherapy. Ribosomal protein L24 has been reported to be a potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cell growth of cancer. MATERIALS AND METHODS: Total RNA of cultured amycin-resistant and susceptible HepG2 cells was isolated, and real time quantitative RT-PCR were used to indicate differences between amycin-resistant and susceptible strains of HepG2 cells. Viability assays were used to determine amycin resistance in RPL24 transfected and control vector and null- transfected HepG2 cell lines. RESULTS: The ribosomal protein L24 transcription level was 7.7 times higher in the drug-resistant HepG2 cells as compared to susceptible cells on quantitative RT-PCR analysis. This was associated with enhanced drug resistance as determined by methyl tritiated thymidine (3H-TdR) incorporation. CONCLUSIONS: The ribosomal protein L24 gene may have effects on drug resistance mechanisms in hepatocellular carcinoma HepG2 cells.

[Research of early-warning method for regional groundwater pollution based on risk management].

Groundwater is the main source of water supply in China, and China's overall situation of groundwater pollution is not optimistic at present. Groundwater pollution risk evaluation and early-warning are the effective measures to prevent groundwater pollution. At present, research of groundwater early-warning method at home and abroad is still at the exploratory stage, and the sophisticated technology has not been developed for reference. This paper briefly described the data and technological demand of the early-warning method in different scales, and the main factors influencing the early-warning results of groundwater pollution were classified as protection performance of geological medium, characteristics of pollution sources, groundwater dynamics and groundwater value. Then the main early-warning indexes of groundwater pollution were screened to establish the early-warning model of regional or watershed scale by the index overlay method. At last, the established early-warning model was used in Baotou plain, and the different early-warning grades were zoned by the model. The research results could provide scientific support for the local management department to protect the groundwater resources.

[Association between genetic polymorphism in DNA repair genes XRCC3 and risks of laryngeal and hypopharyngeal carcinomas].

OBJECTIVE: To study the association between polymorphism of DNA repair gene XRCC3 Thr 241 Met and the risks of developing laryngeal and hypopharyngeal carcinomas. METHODS: One hundred and seventy five patients with laryngeal or hypopharyngeal carcinoma and 525 cancer-free controls were genotyped for the polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression model. RESULTS: The XRCC3 241 Met allele increased the risk of developing laryngeal carcinoma and hypopharyngeal carcinoma. Comparing with subjects having the XRCC3 241 Thr/Thr genotype, the subjects at least having one XRCC3 241 Met allele had OR of 2. 26 (95% CI 1.33 -3.82). Respectively analyzing the risks of laryngeal carcinoma and hypopharyngeal carcinoma, The allele XRCC3 241 Met increased the risks of developing both laryngeal and hypopharyngeal carcinoma. Comparing with the subjects having the XRCC3 241 Thr/Thr genotype, the subjects with laryngeal carcinoma at least having one XRCC3 241 Met genotype had OR of 2.27 (95% CI 1.26 - 4.09); the subjects with hypopharyngeal carcinoma at least having one XRCC3 241 Met genotype had OR of 2. 99 (95% CI 1.27 - 7.04). Smoking may increase the risk of developing laryngeal carcinoma and hypopharyngeal carcinoma. The interaction of smoking and XRCC3 Thr241 Met increased risk of laryngeal carcinoma and hypopharyngeal carcinoma in a super-multiplicative manner. The subjects with heavy smoking and at least having one XRCC3 241Met allele had OR of 19.09 (95% CI 7.38 -49.40) comparing with those having the XRCC3 241 Thr/ Thr genotype and no smoking, which was greater than the multiplication of ORs both of subjects at least having one 241 Met allele meanwhile without smoking (OR, 0.91; 95% CI, 0.20 - 4.21) and of subjects having XRCC3 241 Thr/Thr genotype meanwhile with smoking (OR, 4.13; 95% CI, 2.38 - 7.17). CONCLUSIONS: XRCC3 Thr 241 Met plays an important role in the development of laryngeal and hypopharyngeal carcinoma.

[Correlation of genetic polymorphisms in DNA repair genes ADPRT and XRCC1 to risk of gastric cancer].

BACKGROUND & OBJECTIVE: Adenosine diphosphate ribosyl transferase (ADPRT) and X-ray repair cross-complementing 1 (XRCC1) are 2 major DNA base excision repair (BER) proteins and act interactively in stimulating and executing BER processes. Polymorphisms of ADPRT 762Val-->Ala and XRCC1 399Arg-->Gln have been verified to associate with altered protein function and BER activity. This study was to examine the contribution of these 2 polymorphisms, alone or in combination, to the risk of developing gastric cancer. METHODS: A total of 236 patients with gastric cancer and 708 cancer-free controls were genotyped for the 2 polymorphisms by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) method. Odds ratio (OR) and 95% confidence interval (CI) were calculated using unconditional logistic regression model to evaluate the impact of these 2 polymorphisms on the risk of developing gastric cancer. RESULTS: The subjects having the ADPRT Ala/Ala genotype had an OR of 2.07 (95% CI=1.33-3.21; P=0.001) compared with those having the Val/Val genotype. Gene-gene interaction of ADPRT and XRCC1 polymorphisms increased the risk of gastric cancer in a super-multiplicative manner, with an OR of 5.32 (95% CI=1.12-28.57) for the presence of both ADPRT 762Ala/Ala and XRCC1 399Gln/Gln genotypes, although the XRCC1 polymorphism itself was not associated with the risk of gastric cancer. CONCLUSION: The ADPRT 762Val-->Ala polymorphism plays an important role in the development of gastric cancer, and the XRCC1 399Arg-->Gln polymorphism may serve as a risk modifier.