[Significance of p53 gene mutation and P53 protein expression abnormality on the prognosis of esophageal cancer: a meta-analysis study].

OBJECTIVE: To evaluate the prognostic significance of p53 mutation and P53 protein expression abnormality among esophageal cancer. METHODS: The results of 27 random controlled trials from 1990 to 2003 were analyzed by meta-analysis method. The overall positive rate of p53 was 52.9% among the cumulative 2174 cases. Relative hazard (RH) was applied to evaluate the risk of disease and all data were analyzed by Dersimonian-Laird method. RESULTS: The analysis for homogeneity (q statistics test) showed that all eligible studies were with heterogeneity (q = 59.88, P < 0.005). The combined RH was 2.07 and 95% confidence interval was 1.58-2.70. CONCLUSION: Findings showed that p53 was a poor prognosis biomarker for esophageal cancer gene diagnosis but might benefit to the strategy of treatment.

[Logistic analysis on risk factors related to smear positive pulmonary tuberculosis].

OBJECTIVE: To explore the risk factors on relapsing tuberculosis related to smear positive pulmonary tuberculosis which had been cured for five years. METHODS: Patients with smear positive pulmonary tuberculosis registered in 1995 from ten countries in Hubei province were studied and logistic regression was used for data analysis. RESULTS: The 5-year relapse rate of smear positive pulmonary tuberculosis was 3.85 percent. Risk factors related to relapse would include being non-modeled county, negative smear after treated for three months, the class of retreatment, management of non-DOTS, method of chemotherapy and patients that did not get treated by the tuberculosis institute, with odds ratios of 0.15, 4.62, 3.68, 5.88 and 6.47, respectively. CONCLUSION: Effect standard, regulation DOTS and the centralized management measure might have had effects on decreasing the relapse rate.

[Study on the application of artificial neural network in analysing the risk factors of diabetes mellitus].

OBJECTIVE: To study the use of neural network in determining the risk factors of diseases. METHODS: With back-propagation neural network (BP network) as fitting model based upon data gathered from an epidemiological survey on diabetes mellitus and under the network structure of 22-6-1, the mean impact value (MIV) for each input variables and sequencing the factors according to their absolute MIVs were calculated. The results from BP network with multiple logistic regression analysis and log-linear model for united actions between factors were compared with optimizing Levenberg-Marquardt algorithm. RESULTS: By BP network analysis, the sequence of importance for the risk factors of diabetes mellitus became: faster pulse, diabetes mellitus family history, living longer in the investigated area, with medical record of nephropathy, having higher ratio for waist-to-hip, being male, with medical records of diseases as hyperlipoproteinmia, coronary heart disease, hypertension, high diastolic pressure, higher income, do no drink alcohol, age, higher systolic pressure, less educated, body mass index, with medical records of other diseases, physical exercise related to jobs smoking, occupation, with medical record for cerebrovascular disease, with medical record for liver disease etc. However, only 7 factors were statistically significant in multiple logistic regression analysis. The sequence of their importance appeared as: pulse, diabetes mellitus family history, the medical record of nephropathy, waist-to-hip ratio, the medical record of hypertension, work-place related exercise and age. The sequences of importance were almost the same between the two while the difference could partly be explained by the interaction among risk factors through log-linear model. CONCLUSION: Neural network could be used to analyze the risk factors of diseases and could assimilate more complicated relationships (main effects and interactions) between inputs and outputs, better than using the traditional methods.

Polymorphisms in the DNA repair gene XPD and susceptibility to esophageal squamous cell carcinoma.

Polymorphisms of the nucleotide excision repair gene XPD are candidates for influencing cancer susceptibility. To determine the effect of XPD genetic polymorphisms on the risk of esophageal squamous cell carcinoma (ESCC) and its interaction with carcinogen exposure, XPD polymorphisms at codon 312 (Asp-->Asn) and codon 751 (Lys-->Gln) were determined in 135 ESCC patients and 152 normal controls. Polymorphism at codon 312 made no contribution to genetic risk for ESCC. Our results showed that there was a significant difference between frequencies for XPD 751 Gln/Gln genotype in ESCC patients (8.9%) and normal cases (1.3%), and that Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio [OR] = 6.71; 95% confidence interval [CI]: 1.90-23.73). The results of the logistic regression model showed that XPD 751 Gln/Gln genotype and drinking were candidates for influencing the risk of ESCC. Among smokers, the risk of ESCC in XPD 751 Gln/Gln genotype increased 8-fold than that XPD 751 Lys/Lys genotype (OR = 8.42, 95% CI: 1.02-69.58). The results indicated that XPD 751 Gln/Gln genotype may be contributing factors in the risk of ESCC and may modify risk attributable to environmental exposures.

DNA repair gene XRCC1 polymorphisms, smoking, and esophageal cancer risk.

To investigate the effect of X-ray repair cross complementing 1 (XRCC1) genetic polymorphisms on esophageal cancer risk, we determined XRCC1 polymorphisms at codon 194 (Arg --> Trp) and codon 399 (Arg --> Gln) in 135 patients with esophageal squamous cell carcinoma (ESCC) and 152 normal controls from hospitals. Although polymorphism at codon 194 was not associated with risk for ESCC, we found that the frequency of XRCC1 399 Gln/Gln genotype in ESCC patients (14.1%) was significantly higher than that in normal controls (3.3%), and that XRCC1 399 Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio (OR) = 5.15, 95% confidence interval (CI): 2.42-0.93). In addition, we found that the risk for smoker increased 4.2-fold than non-smokers in the 399 Gln/Gln genotype (OR = 4.20, 95% CI: 2.37-7.44). These results suggest that XRCC1 399 Gln/Gln genotype may contribute to the risk of ESCC and modify risk associated with smoking.

[The control study on risk factors of high-risk population in diabetes].

OBJECTIVE: To examine the significance of individual risk on diabetes to subjects who underwent diabetes screening. METHODS: 2003 asymptomatic diabetes subjects with high-risk factors of diabetes as family history, obesity, hypertension, and/or dyslipidemia, fetal giant history were screened. 5362 subjects having no risk factors but from the same community were allocated as controls. RESULTS: There were 131 (6.54%) diabetes identified in the screening group and 1547 (77.23%) subjects having 1 risk factor, 387 (19.27%) having 2 risk factors, 70 (3.49%) having 3 or more risk factors. There were 96 (1.79%) diabetes identified in the control group. Compared with control group, the OR (95% CI) value was 2.68 (2.20-3.25) after adjusted on age among the high risk group. The OR value of those having 1 risk factor was 2.89, but these having 3 or more risk factors increased to 4.68. CONCLUSION: The relation between the risk of high-risk group with diabetes and the number of risk factors of diabetes presented positive correlation. Early and regular screening for diabetes was essential in these individuals with high-risk factors.

[Re-evaluation of marketed chemical drugs and biological products of therapeutic - a systematic review of literature].

OBJECTIVE: To assess the current status on re-evaluation of marketed drug in China since the promulgation of drug law in 1985. METHODS: Review of literature on Chinese pharmaceutical abstract and CBMdisc from 1985 to 2001 year was done. RESULTS: 4029 papers and 855 marketed drugs from 1985 to 2001 were included. Drugs on anti-infection agent, cardiovascular system and digestive system were the main drugs being re-evaluated, with the proportions of 27.1%, 20.1% and 11.1% respectively. The amounts of both marketed drugs and literature were increasing year by year. The method used for re-evaluation were random and non-random clinical trial. 41.4% of all the samples had a sample size of 50 - 100 research subjects. There were 13 papers with more than 5000 samples. The level on evidence based literature was assessed. 44 papers were graded as first class, and 182 papers the second, 2466 papers the third and 1337 papers the fourth. The quality of literature was improved year by year. CONCLUSION: The amount, quality as well as the sample size of literature being re-evaluated on marketed drug were increased from 1985 to 2001. However, the design and evaluation of those trials were not standardized.

Awareness and attitudes of healthcare professionals in Wuhan, China to the reporting of adverse drug reactions.

BACKGROUND: A voluntary procedure for reporting adverse drug reactions (ADRs) was formally put in place in 1989. However, only a small proportion of ADR reports are actually forwarded to the national monitoring center. To identify the reasons for underreporting, the authors investigated the awareness and attitudes of healthcare professionals (doctors, nurses, and administrators) toward the ADR system in China. In addition, the authors sought to formulate approaches to improve the current ADR reporting system. METHODS: Structured interviews were carried out in 16 hospitals selected from 27 municipal hospitals in Wuhan, Hubei Province, China. A questionnaire survey of a stratified random sample of approximately 15% of healthcare professionals in each selected hospital was conducted during February to March 2003. RESULTS: The response rate of this survey was 85%. One thousand six hundred and fifty-three questionnaires were used in the final analysis. Only 2.7% of the healthcare professionals had a correct understanding to the definition of ADR. Eighty-nine point two percent of the healthcare professionals had encountered ADRs. Ninety-four percent of them were aware of the need to report these to the ADR monitoring center. However, only 28.5% of doctors, 22.8% of nurses, and 29.7% of administrators actually submitted a report. For the most part, they reported ADRs to the hospital pharmacy (66.0%), to other departments in the hospital (72.5%), and to the pharmaceutical industry (23.0%), rather than to the national monitoring center (2.9%) or regional monitoring center (9.5%). Severe or rare ADRs and ADRs to new products were generally perceived to be significant enough to report. Sixty-two point one percent of the healthcare professionals had encountered ADRs, yet not reported them to anybody. The major reasons for not reporting included no knowledge of the reporting procedure (71.4%), unavailability of the reporting center mailing address (67.9%), unavailability of the ADR report form (60.4%), lack of knowledge of the existence of a national ADR reporting system (52.2%), and belief that the ADR in question was already well known (44.1%). CONCLUSIONS: Healthcare professionals in Wuhan, China have little basic knowledge of ADR and of the voluntary reporting system. The main reasons for underreporting were lack of basic knowledge about ADRs and the voluntary reporting procedure. Education and training of healthcare professionals is needed to improve the current ADR reporting system.

Expression of cyclooxygenase-2 (COX-2) in human esophageal cancer and in vitro inhibition by a specific COX-2 inhibitor, NS-398.

BACKGROUND: The purpose of the present paper was to study the expression of cyclooxygenase-2 (COX-2) in normal squamous epithelium, squamous dysplasia and squamous cell carcinoma (SCC) of the esophagus, to elucidate the role of COX-2 in esophageal carcinogenesis, and to evaluate the in vitro effect and mechanism of a COX-2 inhibitor, NS-398, in inducing growth inhibition and apoptosis of human esophageal cancer cells. METHODS: Biopsy specimens of esophageal dysplasia (n = 21), and surgical resections of SCC (n = 37) were compared with normal esophagus (n = 37) and analyzed by RT-PCR. Human esophageal cells were used for the study. Anti-proliferative effect was measured by MTT, apoptosis was determined by DNA fragmentation assay. RESULTS: Marked COX-2 expression was shown in SCC and esophageal squamous dysplasia, and no marked COX-2 expression was observed in the normal squamous epithelium, respectively. NS-398 could inhibit esophageal cells growth in a dose-dependent manner, induce apoptosis, and elevate caspase-3 activity in vitro. CONCLUSIONS: This study provides evidence that COX-2 is upregulated in the majority of cases of squamous dysplasia and SCC of esophagus, and that NS-398 can inhibit growth and induce apoptosis via activating caspase-3 activity in vitro. These results suggest that selective inhibitors of COX-2 may be an effective preventive and therapeutic option for esophageal carcinoma.

[Expression of cyclooxygenase-2 in esophageal squamous cell carcinogenesis].

OBJECTIVES: To investigate the expression of cyclooxygenase-2 (cox-2) protein in normal squamous epithelium, squamous dysplasia and squamous cell carcinoma of the esophagus, and to elucidate the role of cox-2 in esophageal carcinogenesis. METHODS: Biopsy specimens of atypical esophageal dysplasia (n = 47) and surgical resection of squamous cell carcinoma (n = 86) were compared with normal esophageal specimens (n = 42) and the expression of cox-2 in those specimens was analyzed by immunohistochemistry and western blotting. RESULTS: A significant elevated cox-2 expression was shown in atypical esophageal squamous dysplasia and squamous cell carcinoma, as compared to that in normal esophageal squamous epithelium, with immunohistochemical stain scores of 2.67 +/- 1.77, 2.19 +/- 1.79 and 0.71 +/- 0.46, respectively. Results of western blotting analysis confirmed those obtained by immunohistochemistry. Cox-2 expression significantly correlated with proliferation activity assessed by proliferating cell nuclear antigen index in dysplastic and carcinomous lesions, respectively, and no such correlation could be found in normal esophageal mucosa. Elevated cox-2 expression was not associated with clinical-pathological features of esophageal squamous carcinoma, including age, gender, tumor size, histological grade, lymph node metastasis and clinical stage. CONCLUSION: Elevated expression of cox-2 in atypical squamous dysplasia and squamous cell carcinoma of the esophagus, which correlated with cell proliferation activity, indicated that cox-2 may be involved in the early stage of squamous carcinogenesis of the esophagus, and may be a target of prevention and treatment for esophageal squamous cell carcinoma.

[Study on the knowledge and attitude to adverse drug reactions reporting among healthcare professionals in Wuhan city].

OBJECTIVE: To investigate the knowledge and attitudes of healthcare professionals (doctors, nurses and administrators) to adverse drug reactions (ADR) in Wuhan city and to identify the reasons for under-reporting. METHODS: Structured interviews were carried out in Wuhan, Hubei province. Questionnaire survey to approximately 15% of the medical practitioners selected from 16 hospitals, was conducted during the period from February to March 2003. RESULTS: Only 2.7% of the interviewees knew the definition of adverse drug reactions. 61.7% of the doctors, 62.7% of the nurses and 61.1% of the administrators had ever encountered an ADR during their practices, but did not report to the national monitoring center or other centers. The major reasons for not reporting included: ignorant about the requirement and the reporting process of ADR (71.4%); address of the reporting agency and Forms unavailable (67.9%, 60.4%); unaware of the existence of a national ADR reporting system (52.2%); needless to report as the ADR being too well known (44.1%). They mainly reported an ADR to the hospital pharmacy or other departments, or to the pharmaceutical administration. Education, training and developing new institutions were ways to improve the reporting system. CONCLUSIONS: Our results showed that healthcare professionals had little knowledge on the basic ADR knowledge. The main reasons for underreporting were related to factors on reporting process, address of related centers and unavailable of the Forms. Education and training to doctors and nurses to enhance the awareness of administrators were the ways to improve the reporting system.

[Study on the evolutionary pressure on the env gene of the human immunodeficiency virus type 1 CRF01-AE strains circulating in China].

OBJECTIVE: To identify variations in the env gene of human immunodeficiency virus type 1 (HIV-1) subtype CRF01-AE strains circulating in China and to elucidate the potential relationship between genetic variation and evolutionary pressure. METHODS: Fragments of the HIV-1 env gene were amplified by nested-polymerase chain reaction (n-PCR) from the whole blood of HIV-1 infected individuals from four provinces in Southeast China (Guangdong, Hunan, Jiangsu and Jiangxi). The PCR products were then directly sequenced by ABI 377 DNA sequencers. The sequences covering the env V3-V4 region of 34 HIV-1 subtype CRF01-AE strains were selected to analyse phylogenetic trees and amino acid mutations. The accumulation of synonymous (Ks) and antonymous (Ka) substitutions as well as Ks/Ka ratios were calculated using DIVERGE. RESULTS: Phylogenetic trees showed that the 34 HIV-1 subtype CRF01-AE strains from China clustered with the Chinese AE reference strain (AE.97CNGX2F), as well as with the reference strains from Thailand (AE.CM240 and AE.93TH253). The amino acid sequences of the env V4 and C3 regions in the samples were highly variable, compared with those of V3 and V3-downstream regions. The V3 loop central motif in the majority (87.5%) of the strains was GPGQ. The majority of strains did not contain positively charged amino acids at positions 306 and 320 in V3 loop. The N-linked glycosylation sites in the V3-V4 region and flanking regions in these strains were relatively conserved. Analysis of the entire region showed that the mean Ks values were significantly higher than that of the Ka values (P < 0.001), with the Ks/Ka significantly higher than 1.0 (P < 0.001). In contrast, the Ks/Ka ratio in the V4 region was significantly lower than 1.0 (P < 0.01). CONCLUSIONS: Our study indicated that the majority of HIV-1 subtype CRF01-AE strains circulating in China were highly homogeneous. The amino acid sequences of the V4 and C3 regions were significantly more variable than those of the V3 loop. Our analysis also suggested that the phenotype of nearly all strains was likely to be non-syncytium inducing (NSI). Finally, the variation found in the V3-V4 sequence was significantly influenced by functional constraints as opposed to positive selective pressure, while the variability of the lone V4 region was strongly related to positive selective pressure.

[Expression of telomerase reverse transcriptase in premalignant esophageal squamous dysplasia].

OBJECTIVE: To study the relationship of human telomerase reverse transcriptase (hTRT) and malignant transformation of esophageal dysplasia. METHODS: Telomerase activity and hTRT expression in esophageal dysplasia (n = 47), squamous cell carcinoma (n = 29) and normal esophagus (n = 11) were detected by telomeric repeat amplification protocol (TRAP) and in situ hybridization, respectively. RESULTS: Telomerase activity was detected in none of the 11 cases of normal esophageal tissues (0%) but in 21 of 47 cases (44.7%) of dysplasia, and in 25 of 29 cases (86.2%) of esophageal squamous cell carcinoma. There were statistically significant differences among the telomerase activity in normal esophagus, esophageal dysplasia, and in squamous cell carcinoma (chi(2) = 5.89, P < 0.05; chi(2) = 11.35, P < 0.01). hTRT mRNA was expressed in none of the 11 cases of normal esophageal tissues (0%) but in 23 of 47 cases (48.9%) of dysplasia, and in 24 of 29 cases (82.8%) of esophageal squamous cell carcinoma. There were statistically significant differences among the expression of hTRT mRNA in normal esophagus, esophageal dysplasia, and in squamous cell carcinoma (chi(2) = 6.99, P < 0.01; chi(2) = 7.32, P < 0.01). Significant correlation was found between the telomerase activity and the expression of hTRT mRNA (chi(2) = 57.91, P < 0.001). CONCLUSION: The mRNA expression of hTRT which paralleled to telomerase activity implied that there was a crucial role to play in regulating the activation of telomerase, and was closely related to the malignant transformation of esophageal dysplasia. hTRT might serve as a new, valuable biomarker to detect esophageal squamous cell carcinoma.

[Comprehensive evaluation and trend prediction of risk factors on breast cancer].

OBJECTIVE: To comprehensively analyse and evaluate the risk factors and to predict the trend of breast cancer in China. METHODS: Collecting the articles on case-control studies related to breast cancer in the last 10 years in China. Calculating the relative risk (OR) and 95% confidence interval (95%CI) of risk factors by the random effect model of Meta-analysis to estimate present and future population attributable risk percent (PARP) based on the exposure rate of risk factor and to predict the change of incidence rates of breast cancer during the following 5 years with the change of exposure rates. RESULTS: Twenty-two articles referred to case-control studies on breast cancer were selected. The OR and its 95%CI of the first 5 risk factors of breast cancer in China were benign breast lesion 3.39 (2.97 - 3.86), psychological stimulation 2.36 (2.09 - 2.67), breast-feeding 1.95 (1.54 - 2.47), family history of tumor 1.84 (1.63 - 2.08) and menstruation 1.65 (1.44 - 1.89). The factors with higher PRAP were benign breast lesion, breast-feeding, psychological stimulation with PRAR 15.47%, 15.17%, 13.76%, respectively. Their PRAP would have decreased to 12.77%, 11.32%, 12.52% and 9.90%, 8.74%, 9.69% respectively if the exposure rates had decreased 20% and 40% in the next 5 or 10 years. Factors contributing to the change of incidence rate of breast cancer would include benign breast lesion, breast-feeding, psychological stimulation along with the change of exposure rate. The incidence rates of breast cancer would then have become 3.09%, 2.75%, 3.03% and 6.19%, 5.50%, 6.07% respectively if their exposure rate had decreased 20% and 40% in the next 5 or 10 years. CONCLUSION: Decreasing benign breast lesion, avoiding psychological stimulation, advocating on breast-feeding seemed to be the effective measures to control the occurrence and development of breast cancer.

Cyclooxygenase-2 expression in squamous dysplasia and squamous cell carcinoma of the esophagus.

Cyclooxygenase-2 (cox-2) overexpression has been observed in several types of human cancers and has been implicated in carcinogenesis. To elucidate the role of cox-2 in esophageal carcinogenesis, we evaluated the expression of cox-2 in normal squamous epithelium squamous epithelial dysplasia (n=47), and squamous cell carcinoma of the esophagus (n=86) by immunohistochemistry, reverse transcription-PCR assay, and western blotting. A significant overexpression of cox-2 was observed in esophageal squamous dysplasia and squamous cell carcinoma compared with normal squamous epithelium. The immunoreactive score of cox-2 expression, an index determined by intensity and positivity of cox-2 staining, was 0.71 +/- 0.46 (mean +/- SD) in normal squamous esophagus, 2.19 +/- 1.79 in squamous epithelial dysplasia, and 2.67 +/- 1.77 in squamous cell carcinoma. The results of immunohistochemistry were confirmed by a reverse transcription-PCR assay and western blotting analysis. Cox-2 expression level was correlated with proliferation activity assessed by proliferating cell nuclear antigen (PCNA) index and MIB-1 index in dysplastic lesion (r=0.55, P<0.01 with PCNA and r=0.72, P<0.01 with MIB-1) and carcinoma (r=0.56, P<0.01 with PCNA and r=0.72, P<0.01 with MIB-1). Elevated cox-2 expression was associated with high p53 expression (p<0.001) but not with clinicopathological features including age, sex, tumor size, histological grade, lymph node metastasis, and TNM stage. The results indicated that cox-2 may be involved in an early stage of squamous carcinogenesis of the esophagus, and that cox-2 overexpression was related to cell proliferation in esophageal squamous dysplasia and squamous cell carcinoma.

[Sequence variation in the env V3-V4 region of HIV type 1 predominant subtype B and C strains circulating in China].

OBJECTIVE: To identify genetic variation of HIV-1 predominant subtype B and C strains in China during rapid horizontal transmission and to elucidate the potential relationship between genetic variation and selective pressure. METHODS: After the fragments of HIV-1 env gene were amplified by nested-PCR from the whole blood of 258 HIV-1 infected individuals, PCR products were directly sequenced using ABI 377 DNA sequencer. The sequences covering env V3-V4 region of 72 HIV-1 subtype B(n=37) and C(n=35) strains were selected for phylogenetic analysis. In addition, the ratios of synonymous (Ks) substitutions per nonsynonymous (Ka) substitutions were calculated using DIVERGE. RESULTS: The genetic distances of the V3-V4 region of subtype B strains were higher than that of subtype C strains. Furthermore, sequence analysis revealed that the V4 region was more variable than the V3 region for both subtype B and C strains. What's more, the V3 loop was less variable compared with the V3 upstream region and C3 region for subtype C Ks/Ka ratios of the entire aligned sequence of the two subtypes were below 1 0, with the lowest values found in the V3 region of subtype B strain and the V4 region of subtype C strain. CONCLUSIONS: The majority of variation in both subtypes B and C strains occurred in the V4 rather than the V3 region. It is important that our study found for the first time the V3 loop was more conservative than the V3 upstream region and C3 region for subtype C. Calculations of the Ks/Ka ratios throughout the V3-V4 region demonstrate that significant selective pressures experienced during the rapid horizontal spread of the virus in the Chinese HIV-1 infected population may have directed change in the V3 loop for the subtype B strain and the V4 loop for the subtype C strain. These results will contribute to the policy of AIDS prevention and control and the ongoing development vaccine.

[A study on the role of DNA repair gene O6-methylguanine-DNA methyltransferase in the development of human lung cancer].

OBJECTIVE: To study the role of O(6)-methylguanine-DNA methyltransferase (hMGMT) in the development of human lung cancer. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) method was applied to measure hMGMT mRNA expression in 150 lung cancer specimens, 40 normal lung tissues, and in the peripheral mononuclear blood cells from 50 lung cancer cases and 50 normal controls. The protein expressions of p53, C-MYC and K-RAS were assessed by immuno-histochemistry. The effects of some exposure factors on the expression of hMGMT gene were analyzed. The relationships between hMGMT gene and cancer related genes p53, C-MYC and K-RAS were investigated. RESULTS: The mRNA of hMGMT was low or absent in 49 of 150 (32.7%) lung cancer specimens, whereas 2 of 40 (5%) normal lung tissues had reduced the levels of hMGMT mRNA. The low expression of hMGMT seemed to be a risk factor of lung cancer, with a OR of 9.22 (2.05-57.65). Reduced expression levels of hMGMT mRNA were observed in 10 of 50 (20%) lung cancer patients' peripheral mononuclear blood cells, and 2 of 50 (4%) blood cells among normal controls. When investigating the exposure factors which affecting the expression of hMGMT gene, we noticed that smoking was suppressing the expression of hMGMT gene. Interestingly, over-expression of K-RAS oncogene was significantly correlated with low expression of hMGMT (P < 0.05). However, the expressions of p53 and C-myc were not correlated with the status of hMGMT gene. CONCLUSION: hMGMT might play an important role in the development of human lung cancer. Low expression of hMGMT gene seemed to be a risk factor for lung cancer which could be used as a valuable biomarker on susceptibility of human lung cancers.

[Meta-analysis of the risk factors on lung cancer in Chinese people].

OBJECTIVE: To provide evidence for decision-making on lung cancer prevention through studying the main risk factors related to the incidence of lung cancer in Chinese people. METHODS: The results from 41 epidemiological studies on risk factors of lung cancer from 1990 to 2001 were analyzed synthetically by Meta-analysis. The cumulative cases and controls were 5,600 and 6,892, respectively. RESULTS: The pools odds ratio (OR) values of mentality (3.34), smoking (3.04), indoor coal pollution (3.20), indoor cooking oil fume pollution (2.72), family history of lung cancer (2.61), vegetables (0.49), fruits (0.69), BMI (1.57), family history of other tumour (2.97), personal history of respiratory system diseases (2.66), ventilation in kitchen (2.13), coal ever used in life (1.50), and exposure to environmental tobacco smoking (1.42). CONCLUSION: The main factors influencing the incidence of lung cancer in Chinese people were patients, mentality, smoking, indoor environmental pollution, personal history of respiratory system diseases, family history of cancer, intake of vegetables, fruits and so on.

[Study on lung carcinogenesis associated genes in human lung squamous cell carcinoma and malignant transformation of human bronchial epithelial cells induced by carcinogen].

OBJECTIVE: To investigate lung carcinogenesis associated genes in human lung squamous cell carcinoma and malignant transformation of human bronchial epithelial cells induced by chemical carcinogens with cDNA microarray. METHODS: The gene expression patterns were detected in all specimens by cDNA microarray which representing 4 096 different human genes. The differences in gene expression among 6 cases of human lung squamous cell carcinoma tissues and 6 normal lung tissues were analyzed. The different gene expression patterns between the normal human bronchial epithelial cell lines (16HBE) and the malignant transformation of human bronchial epithelial cells induced by Benzo(a)pyrene metabolite BPDE (anti-Benzo(a)pyrene diol-epoxide,BPDE) and crystalline nickel sulfide were also studied by that method. The similar changed genes among those gene expression patterns were identified as lung carcinogenesis associated genes. RESULTS: Among the 4096 genes of cDNA microarrays, there were 171 genes expressed differently among lung cancer tissues and normal lungs, 143 genes expressed differently between BPDE transformed cells and normal 16HBE cell lines, 151 genes differed between nickel sulfide transformed cells and normal 16HBE cell lines. By comparing the gene expression profiles, there were 89 similar changed genes which might be associated with human lung carcinogenesis, 39 of which were up regulated: 6 oncogenes, 4 cell cycle control genes, 6 cell proliferation genes, 8 metastasis genes, 3 neuroendocrine genes, 1 drug-resister gene, 1 anti-apoptosis gene, 1 oxidative gene and other 9 genes. 50 genes were down-regulated: 7 tumor suppression genes, 11 DNA repair genes, 1 antioxidant genes, 3 GST family genes, 3 cell framework genes, 2 apoptosis induced genes, 5 signal conduction genes, 5 cytokines and their receptor genes, 7 metabolization genes, 1 cell matrix genes, and other 5 genes. CONCLUSION: cDNA microarray can be applied to study gene expression profiles effectively and to screen human lung carcinogenesis associated genes.

[Study on the epidemiology and risk factors of renal calculi in special economic zone of Shenzhen city].

OBJECTIVE: To study the epidemiological characters and risk factors of renal calculi in Shenzhen for future intervention. METHODS: Risk factors of renal calculi were analyzed by factor analysis and linear structural relation model, followed by fitting and evaluating the model. RESULTS: The prevalence rates of renal calculi were 8.00% and 5.12% in males and females. The results of LISEREL showed that the total effect of age and sex affecting the development of renal calculi was 0.4614, with directly effect 0.3600 and indirect 0.1014. The direct effects of blood uric acid, blood calcium and body mass index, blood cholesterol, blood sugar were 0.3400 and 0.3200 respectively. The indirect effect of education, exercise and dietary habit affected the development of renal calculi through index of biochemistry and obesity, were -0.0416 and 0.1882. CONCLUSION: Sex, age, obesity and high blood cholesterol, high blood sugar, high blood uric acid, high blood calcium were the direct influencing factors to renal calculi. At the same time, education, exercise and dietary habit were also associated with the disease.