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Biomedical subjects

Na Liu

Publications and source records attributed to Na Liu.

At least 37 records · Page 2Linked to original sources

[Effects of mild hypothermia on expression of N-methyl-D-aspartate receptor-1 in hippocampus neurons after cardiopulmonary resuscitation in rats].

OBJECTIVE: To explore the effects of mild hypothermia on expression of N-methyl-D-aspartate receptor-1 (NMDAR1) in hippocampus neurons after cardiopulmonary resuscitation (CPR) in rats. METHODS: Twenty-four male SD rats were randomly divided into normal control group, normal temperature group, and mild hypothermia group, with 8 rats in each group. The cerebral edema model after CPR was replicated by the sealed bottle method in rats in both normal temperature group and mild hypothermia group. The rats in the mild hypothermia group were treated with mild hypothermia after the model was established. The change in expression of NMDAR1 in hippocampus neurons in rat was determined with semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and pathologic changes in brain tissue were observed in both groups. RESULTS: The cerebral edema was ameliorated, NMDAR1 mRNA and protein in cerebral hippocampus neurons were significantly lower in hypothermia group than control group with significant difference (NMDAR1 mRNA: 80.48+/-0.03 vs. 80.64+/-0.18, P<0.05 ). CONCLUSION: Mild hypothermia can down regulate the expression of NMDAR1 mRNA and protein level, lower positive ion concentration and thus decrease cerebral edema, so mild hypothermia can serve as a treatment measure for cerebral edema after CPR.

Animals↗

Expression of delayed rectifier potassium channels and their possible roles in proliferation of human gastric cancer cells.

Voltage-gated potassium (Kv) channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the Kv channels and related channel activity are involved in the neoplastic process. Our previous study has shown the existence of delayed rectifier potassium (I(K)) current in gastric cancer cells SGC7901. However, the expression and function of most delayed rectifier potassium (K(D)) channel subunits in gastric cancer cells are not completely resolved. Here we examine expression of K(D) channel subunits in Kv1-Kv3 families in immortalized gastric epithelial cells GES and various gastric cancer cells (including AGS, KATOIII, MKN28, MKN45, MGC803, SGC7901, SGC7901/ADR and SGC7901/VCR), and their roles in cell proliferation. RT-PCR analysis reveals that all cell lines examined express Kv1.3, Kv1.5, Kv1.6, Kv2.1 and Kv2.2. However, Kv1.2 and Kv3.2 genes are barely detectable in any given cancer cell lines. Kv1.5 protein, high mRNA levels in all cell lines examined, is also expressed in some cancer cells lines and more frequently detected in gastric cancer tissues. Downregulation of the expression of Kv1.5 in SGC7901 with RNA interference significantly inhibited the proliferation and tumorigenicity of SGC7901 cells. Moreover, in Ca(2+)-containing rather than Ca(2+)-free medium, KCl (50mM) stimulated a rapid increase in the concentration of cytosolic calcium in empty vector transfected cells that was blocked by verapamil. Likewise, decrease the expression of Kv1.5 with short interfering RNA also blocked the depolarization-induced influx of Ca(2+). This finding suggests that more than one kind of K(D) channel subunits are expressed in various gastric cancer cell lines. Kv1.5 may be involved in tumor cells proliferation by controlling Ca(2+) entry, and the interference of K(D) channels expression and/or activity could provide a novel strategy to reverse the malignant phenotype of gastric cancer cells.

Calcium↗

Dual-specificity phosphatase DUSP1 protects overactivation of hypoxia-inducible factor 1 through inactivating ERK MAPK.

Hypoxia-inducible factor 1 (HIF-1) plays a critical role in controlling oxygen delivery and metabolic adaptation to hypoxic conditions in hypoxic tumor cells. HIF-1 activation is initiated by several factors including mitogen-activated protein kinase (MAPK) superfamily. We have previously reported that mitogen-activated protein kinase phosphatase DUSP1 (MKP-1) was implicated in the negative regulation of HIF-1alpha subunit phosphorylation and HIF-1 activity. However, the molecular basis by which MKP-1 influences HIF-1 activity is not clarified. In this paper, we show that hypoxia transcriptionally induces MKP-1 expression in a time-dependent manner. Meanwhile, hypoxia also activates extracellular signal-regulated kinase (ERK) whose activity is enhanced or reduced by MKP-1 suppression or MKP-1 overexpression, respectively. We also show that suppression of MKP-1 expression facilitates the interaction between HIF-1alpha subunit and p300, a co-activator of HIF-1. Moreover, MKP-1 suppression leads to enhanced HIF-1 activity, which can be counteracted by PD98059, an ERK kinase inhibitor. Taken together, the results presented here suggest that hypoxia-induced MKP-1 protects overactivation of HIF-1 activation through inhibiting ERK kinase activity.

Cell Cycle Proteins↗

Oral attenuated Salmonella typhimurium vaccine against MG7-Ag mimotope of gastric cancer.

AIM: To develop an oral attenuated Salmonella typhimurium vaccine against gastric cancer and to evaluate its efficacy in mice. METHODS: A complementary sequence of Nco I site and a sequence coding for MG7-Ag mimotope were designed at the 5' terminus of forward primer. Using p1.2 II-HBCAg plasmid as template, PCR was performed to get a fusion gene of the mimotope and a HBcAg gene. The fusion gene was then subcloned into the plasmid pYA3341 complementary to Salmonella typhimurium X4550, and the recombinant plasmid was then transformed into attenuated Salmonella typhimurium X4550. Balb/c mice were orally immunized with the recombinant Salmonella typhimurium X4550. The mice were immunized every 2 wk to reinforce the immunity. At the 6th wk, serum titer of antibody was detected by ELISA, and at the 8th wk, cellular immunity was detected by (51)Cr release test. Ehrlich ascites carcinoma cells expressing MG7-Ag were used in tumor challenge assay as a model to evaluate the protective effect of the vaccine. RESULTS: Serum titer of antibody against MG7-Ag was significantly higher in mice immunized with the vaccine than in control groups (0.9538+/-0.043 vs 0.6531+/-0.018, P<0.01; 0.9538+/-0.043 vs 0.6915+/-0.012, P<0.01), while in vitro (51)Cr release assay of the splenocytes showed no statistical difference in the three groups. Two weeks after tumor challenge, 1 in 5 immunized mice was tumor free, while all the mice in the control group presented tumor. CONCLUSION: Oral attenuated Salmonella typhimurium vaccine against the MG7-Ag mimotope of gastric cancer is immunogenic. It can induce significant humoral immunity against tumors in mice, and has some protective effects.

Administration, Oral↗

Regulation of multidrug resistance by ribosomal protein l6 in gastric cancer cells.

Ribosomal proteins (RP) L6 was previously identified as an up-regulated gene in multidrug-resistant gastric cancer cells SGC7901/ADR comparing to its parental cells SGC7901 by subtractive hybridization. The aim of this study was to explore the roles of RPL6 in multidrug resistance (MDR) in gastric cancer cells. Northern and Western blot analysis confirmed that RPL6 was overexpressed in SGC7901/ADR cells. By gene transfection, RPL6 was genetically upregulated in SGC7901 or down-regulated in SGC7901/ ADR cells. Upregulation of RPL6 was associated with enhanced resistance to multiple anticancer drugs (adriamycin, vincristine, etoposide, 5-fluorouracil and cisplatin) and to adriamycin-induced apoptosis. Downregulation of RPL6 reversed MDR and sensitized cells to adriamycin-induced apoptosis. Alteration of RPL6 showed no obvious influence on intracellular adriamycin accumulation, glutathione content and expression of glutathione S-transferase. RPL6 could upregulate Bcl-2 and downregulate Bax in cells. Together, this work demonstrates that RPL6 could regulate MDR in gastric cancer cells by suppressing drug-induced apoptosis.

Antibiotics, Antineoplastic↗

Overexpression and significance of prion protein in gastric cancer and multidrug-resistant gastric carcinoma cell line SGC7901/ADR.

In our previous work, cellular prion protein (PrPc) was identified as an upregulated gene in adriamycin-resistant gastric carcinoma cell line SGC7901/ADR compared to its parental cell line SGC7901. Here we investigate the expression of PrPc in gastric cancer and whether it was involved in multidrug resistance (MDR) of gastric cancer. We demonstrated that PrPc was ubiquitously expressed in gastric cancer cell lines and tissues. PrPc conferred resistance of both P-glycoprotein (P-gp)-related and P-gp-nonrelated drugs on SGC7901, which was accompanied by decreased accumulation and increased releasing amount of adriamycin in PrPc-overexpressing cell line. Inhibition of PrPc expression by antisense or RNAi technology could partially reverse multidrug-resistant phenotype of SGC7901/ADR. PrPc significantly upregulated the expression of the classical MDR-related molecule P-gp but not multidrug resistance associated protein and glutathione S-transferase pi. The PrPc-induced MDR could be partially reversed by P-gp inhibitor verapamil. PrPc could also suppress adriamycin-induced apoptosis and alter the expression of Bcl-2 and Bax, which might be another pathway contributing to PrPc-related MDR. The further study of the biological functions of PrPc may be helpful for understanding the mechanisms of occurrence and development of clinical gastric carcinoma and PrPc-related MDR and developing possible strategies to treat gastric cancer.

Adenocarcinoma↗

Inhibition of gastric cancer angiogenesis by vector-based RNA interference for Raf-1.

Tumor angiogenesis plays an important role in the malignancy of solid tumors. A number of recent studies including our own have suggested that Raf-1 is involved in this process, and may be critical in regulating gene activation of several angiogenesis factors. To further define Raf-1 function in angiogenesis and to explore novel approaches to modulate angiogenesis, we employed the small interference RNA technique to knock-down gene expression of Raf-1 in gastric cancer cell line SGC7901 that expresses a high level of Raf-1. The protein level of Raf-1 in the SGC7901cells was decreased dramatically after transfection with a Raf-1 specific siRNA vector. Further study proved that, VEGF and HIF-1alpha, two angiogenesis promoting factors, were found to be downregulated. And we also find that Vector-based RNA interference for Raf-1 increases transfected gastric cell apoptosis and inhibits cellular proliferation. Our results suggest that Raf-1 may be involved in angiogenesis by controlling the expression of angiogenesis-related factors and provide a possible strategy for the treatment of tumor angiogenesis by targeting Raf-1.

Down-Regulation↗

ATM deficiency induces oxidative stress and endoplasmic reticulum stress in astrocytes.

ATM kinase, the product of the ataxia telangiectasia mutated (Atm) gene, is activated by genomic damage. ATM plays a crucial role in cell growth and development. Here we report that primary astrocytes isolated from ATM-deficient mice grow slowly, become senescent, and die in culture. However, before reaching senescence, these primary Atm(-/-) astrocytes, like Atm(-/-) lymphocytes, show increased spontaneous DNA synthesis. These astrocytes also show markers of oxidative stress and endoplasmic reticulum (ER) stress, including increased levels of heat shock proteins (HSP70 and GRP78), malondialdehyde adducts, Cu/Zn superoxide dismutase, procaspase 12 cleavage, and redox-sensitive phosphorylation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2). In addition, HSP70 and ERK1/2 phosphorylation are upregulated in the cerebella of ATM-deficient mice. This increase in ERK1/2 phosphorylation is seen primarily in cerebellar astrocytes, or Bergmann glia, near degenerating Purkinje cells. ERK1/2 activation and astrogliosis are also found in other parts of the brain, for example, the cortex. We conclude that ATM deficiency induces intrinsic growth defects, oxidative stress, ER stress, and ERKs activation in astrocytes.

Animals↗

Up-regulation of astrocyte cyclooxygenase-2, CCAAT/enhancer-binding protein-homology protein, glucose-related protein 78, eukaryotic initiation factor 2 alpha, and c-Jun N-terminal kinase by a neurovirulent murine retrovirus.

In susceptible strains of mice, infection with the mutant retrovirus MoMuLV-ts1 causes a neurodegeneration and immunodeficiency syndrome that resembles human human immunodeficiency virus-acquired immunodeficiency syndrome (HIV-AIDS). In this study the authors show increased expression of cyclooxygenase-2 (COX-2) in the brainstem tissues of ts1-infected mice. Up-regulated central nervous system (CNS) levels of this enzyme are associated with HIV-associated dementia and other inflammatory and neurodegenerative diseases such as amyotrophic lateral sclerosis, Alzheimer's disease, and Parkinson's disease. In brainstem sections, the authors find that astrocytes surrounding spongiform lesions contain increased amounts of immunoreactive COX-2. COX-2 is also up-regulated in cultured ts1-infected cells from the C1 astrocytic cell line, and activation of c-Jun N-terminal kinase, or JNK, pathway. Markers of endoplasmic reticulum (ER) stress, specifically the CCAAT/enhancer-binding protein (CHOP), the glucose-related protein 78 (GRP78), and phosphorylated eukaryotic initiation factor 2 alpha (eIF2 alpha), were also up-regulated in ts1-infected C1 astrocytes. Up-regulation of COX-2 and the above ER signaling factors was reversed by treatment of the infected cells with curcumin which specifically inhibits the JNK/c-Jun pathway. These findings indicate that the JNK/c-Jun pathway is most likely responsible for COX-2 expression induced by ts1 in astrocytes, and that ts1 infection in astrocytes may lead to up-regulation of both inflammatory and ER stress pathways in the central nervous system. Because COX-2 inhibitors are now widely used to treat inflammatory conditions in animals and humans, this finding suggests that these drugs may be useful for therapeutic intervention in neurodegenerative syndromes as well.

Animals↗

Rapid and accurate genotyping of YMDD motif variants in the hepatitis B virus genome by an improved reverse dot blot method.

By using the "flow-through hybridization" principle, we developed a new, rapid and accurate reverse dot blot (RDB) method to detect lamivudine resistance-associated YMDD motif variants in hepatitis B virus (HBV) genome. The improved RDB method was very fast at simultaneously detecting HBV YMDD wild-type and mutant motifs. In a blind analysis, 100 samples previously genotyped by DNA clonal sequencing analysis were used to evaluate the sensitivity and specificity of this assay. Conventional restriction fragment length polymorphism (RFLP) data were also used to test our method. In blind experiments, our improved RDB method had an accuracy and specificity of 100%, which was much higher than RFLP, which had an accuracy and specificity of only 83.0%. In clinical detection practice, 49 patients highly suspected of lamivudine resistance were successfully diagnosed by this method. Our improved RDB assay is a simple, rapid, cheap, semiautomatic, accurate, sensitive, and contamination-proof method of detecting lamivudine resistance-associated mutants in the human hepatitis B virus genome.

Amino Acid Motifs↗

Quality evaluation of traditional Chinese drug toad venom from different origins through a simultaneous determination of bufogenins and indole alkaloids by HPLC.

A simple and efficient HPLC method has been developed to evaluate the quality of traditional Chinese medicine toad venoms. The major bioactive ingredients, including 10 bufogenins and 4 indole alkaloids in the drug, were separated and quantified on a phenyl-hexyl column with a UV detector. A total of 27 toad venom samples from two species, Bufo bufo gargarizans CANTOR and Bufo melanostictus SCHNEIDER, from the different drug production regions of China, were analyzed. The chromatograms showed significant differences with respect to the samples from different origins. These toad venom samples can be distinctly classified into 4 groups by cluster analysis using the contents of the 14 main constituents, including toad venom samples from B. bufo gargarizans from north China, median China and south China, and samples from B. melanostictus from south China. Toad venom samples from B. bufo gargarizans from median China were considered to be of the highest quality.

Alkaloids↗

[Smoking and passive smoking in Chinese, 2002].

OBJECTIVE: To describe the prevalence of smoking, quitting smoke, and passive smoking in different populations by education status, occupation and geographic distribution. METHODS: Surveillance on risk behaviors in 145 disease surveillance points (DSP) was carried out in 2002 by multi-steps random sampling through questionnaires. 16,407 records had been completed with 16 056 used for analysis. Indicators as smoking, current smoking, average cigarettes smoked and the cost per day, etc., were calculated by weight on age proportions from the 2000 census. RESULTS: Ever-smoking rates in males and females aged 15 and over were 66.0% and 3.1%, respectively with ever-smoking rate dropped 1.8% in whole population, but increased in people aged 15-24. The number of total smokers was about 350 million, 30 million more than that in 1996. There were no obvious geographic differences seen among male, but big difference was seen in female smokers. Higher smoking rates were seen in the northeast and northern parts of the country. Rate of quitting smoking was increasing, from 9.42% in 1996 to 11.5% in 2002, referring to an increase of 10 million quitters. However, the rate of no intention to quit among smokers was still very high--74%. The average cigarettes consumption per person-day was the same as that in 1996--14.8 cigarettes/day, which cost 2.73 RBM/day. The cost was various in different groups of population with a 15 times difference. The level of exposure for passive smokers was not improved. The prevalence of passive smoking in nonsmokers were 53% in 1996 and 52% in 2002. Knowledge on smoking and health condition in population had been greatly improved, but still poor in the western areas. 60% of the people claimed in supporting banning of smoking in public places, 45% supporting the banning of all cigarettes ads, but big difference was seen in different geographic areas. CONCLUSION: The prevalence of smoking in Chinese males had reached its peak, leveling but had not yet obvious dropped. Communication on the knowledge of harm in smoking remained weak since people did not understand or support the strategies on tobacco control, especially in the western areas. Data indicated that the prevalence of tobacco use would not decrease over in short period and the disease burden caused by tobacco use would still be heavy in the next 30-50 years. The government and public health authorities should develop effective tobacco control in no time to decrease disease burden caused by smoking and passive smoking.

Adolescent↗

[Study on diet, physical activities and body mass index in Chinese population in 2002].

OBJECTIVE: To describe the prevalence of behavior on diet, physical activities and body mass index (BMI) in different populations related to factors as education, occupation and geographical distribution. METHODS: Indicators including frequency of taking different foods, intake of cooking oil/fast foods, intensities of physical activities at work, proportion of taking physical exercises during the day, sedentary life style and BMI were calculated based on results from 17 questions of behavior risk factors surveillance (BRFS) questionnaire by weight on age structures from 2000 census. RESULTS: Seventy percentage of the people took vegetable and 40 percent took fruits 5-7 days per week, and over 50 percent of them ate pork/beef/mutton but few of them ate beans and eggs. 25 percent of the people ate chicken/duck/fish/and shrimps 5-7 times per week but another 40 percent ate them only less then once per week. 70% of the people almost never drank milk or milk-products. 15 percent of them consumed sweet and greasy foods 3-7 days per week and 30 percent of them ate smoked food 3-7 days per week in the past 30 days. The proportions of food intake were different under different geographical regions, education levels and occupations. 11.7% of the sample population cooked mainly with animal oil, and 33% of the students had ever been to McDonald's. 11.7%, 20.5%, 44.7% and 23.0% of the subjects engaged in sedentary, light, moderate or heavy physical activities respectively. 18.04% of the subjects took part in physical exercises with different proportions by gender, occupation, education and geographical settings. 8.3% people were slim which was defined as having BMI lower than 18.5 kg/m(2). 68.0% of the people had a BMI as 18.5-23.9 kg/m(2). 23.7% of the subjects were being overweight which was defined as having BMI greater than 24 kg/m(2), among which 8.5% people with a BMI of 24-24.9 kg/m(2). CONCLUSION: The prevalence of overweight and obesity will increase in the next 20-30 years, with the habits of taking more foods with high fat and energy but with less physical activities and keeping the idea as "fattier makes happier". Priorities should be given to changing the diet habit, avoiding over-intake of high fat and high energy plus increasing physical activities through publicity of knowledge on health, policy enforcement and development of supportive environment.

Adult↗

[Study on knowledge, attitudes and behaviors regarding infectious diseases among Chinese people in 2002].

OBJECTIVE: To describe knowledge, attitudes and behaviors on infectious diseases in different Chinese populations by their education levels, occupation and residential districts. METHODS: Data regarding awareness of the transmission routes and prevention strategies on hepatitis, sexually transmitted diseases (STD), acquired immune deficiency syndrome (AIDS) and prevalence rates on a) self-reported STD b) seeking treatment for STD c) source of knowledge on AIDS prevention, were calculated based on results from 17 questions of BRFS questionnaire by weight on age structures from 2000 census. RESULTS: Most people realized that hepatitis, STD and AIDS were important issues in public health. However, their awareness on the transmission routes of these diseases was not satisfied. Moreover, due to the fear of these diseases, 27.6% and 30.1% of the people studied thought that shaking hands with STD patients and HIV carriers could get infected. 9.9% of the people reported that they ever used a condom during the past year. 2.2/1000 of the people reported that they had ever suffered from STD during the past 5 years, with 3.4/1000 in males, 0.9/1000 in females, 4.2/1000 in urban population and 1.6/1000 in rural population. Among these STD patients, 75.0% of them reported that they had ever received treatment in a STD clinic including 38.2% of them reporting that they had ever received treatment in private clinics without license, and 6.7% of them reported that they had ever treated by drugs bought by themselves. 47.0% of people reported that they had received health education materials or information on AIDS prevention from medical workers or through media. 12.1% of the people had been informed that condom use could prevent from STD and AIDS transmission. CONCLUSION: The awareness on hepatitis, STD and AIDS was quite insufficient in the Chinese general population, especially in rural and western part of China. With the development of AIDS epidemic from people with high risk behavior to the general population, China will undertake tremendous disease burdens from AIDS in the future.

Acquired Immunodeficiency Syndrome↗

[Cryopreservation of mouse embryos in ethylene glycol-based solutions: a search for the optimal and simple protocols].

Although ethylene glycol (EG) has been widely used for embryo cryopreservation in domestic animals, few attempts were made to use this molecule to freeze mouse and human embryos. In the few studies that used EG for slow-freezing of mouse and human embryos, complicated protocols for human embryos were used, and the protocols need to be simplified. Besides, freezing mouse morula with EG as a cryoprotectant has not been reported. In this paper, we studied the effects of embryo stages, EG concentration, duration and procedure of equilibration, sucrose supplementation and EG removal after thawing on the development of thawed mouse embryos, using the simple freezing and thawing procedures for bovine embryos. The blastulation and hatching rates (81.92% +/- 2.24% and 68.56% +/- 2.43%, respectively) of the thawed late compact morulae were significantly (P < 0.05) higher than those of embryos frozen-thawed at other stages. When mouse late compact morulae were frozen with different concentrations of EG, the highest rates of blastocyst formation and hatching were obtained with 1.8mol/L EG. The blastulation rate was significantly higher when late morulae were equilibrated in 1.8 mol/L EG for 10 min prior to freezing than when they were equilibrated for 30 min, and the hatching rate of embryos exposed to EG for 10 min was significantly higher than that of embryos exposed for 20 and 30 min. Both rates of blastocyst formation and hatching obtained with two-step equilibration were higher (P < 0.05) than with one-step equilibration in 1.8 mol/L EG. Addition of sucrose to the EG-based solution had no beneficial effects. On the contrary, an increased sucrose level (0.4 mol/L) in the solution impaired the development of the frozen-thawed embryos. In contrast, addition of 0.1 mol/L sucrose to the propylene glycol (PG)-based solution significantly improved the development of the frozen-thawed embryos. Elimination of the cryoprotectant after thawing did not improve the development of the thawed embryos. The cell numbers were less (P < 0.05) in blastocysts developed from the thawed morulae than in the in vivo derived ones. In summary, embryo stage, EG concentration, duration and procedure of equilibration and sucrose supplementation had marked effects on development of the thawed mouse embryos, and a protocol for cryopreservation of mouse embryos is recommended in which the late morulae are frozen in 1.8 mol/L EG using the simple freezing and thawing procedures of bovine embryos after a two-step equilibration and the embryos can be cultured or transferred without EG removal after thawing.

Animals↗

[Implementation of second prevention measures on chronic diseases in Chinese, 2002].

OBJECTIVE: To describe the implementation of secondary prevention measures (blood pressure measure, test of blood lipid, and screening test for breast cancer and cervix uteri) on chronic diseases in different populations. METHODS: The indicators on proportion of receiving blood pressure measurement, tests on blood lipid, screening of breast cancer and cervix uteri in research samples, as well as awareness of the risk of hypertension and hyper lipid were calculated based on results from 1BRFS questionnaire by weight on age structures from 2000 census. RESULTS: 22% and 5% of people under research understood the risk of hypertension and hyper lipid on their health. In addition, proportion of receiving these screening tests in sample populations were low. Secondly, the main target population including females over 50 years old but the proportion of screening breast cancer among those females over 50 years old was lower than that in females over 25 years old. Besides educational, occupational and geographic factors, the types of medical insurance for people also were important factors affecting the proportion of receiving screening tests. CONCLUSION: Screening tests were important second prevention measures for reducing severity of the diseases. Except blood pressure tests among people over 35 years old, proportions of receiving other screening tests were very low. There were significant differences of receiving these screening tests in people by education occupation, geographic areas and types of medical insurance. In addition, the policy of screening was not clear on target orientation. It is necessary for developing guideline of screening to guide the screening programs.

Adult↗

[Injury associated health risk factors in Chinese people, in 2002].

OBJECTIVE: To describe the prevalence of injury associated health risk factors, especially traffic accident/suicide-associated health risk factors in different populations by education, occupation and districts. METHODS: The indicators on traffic peccancy behavior and protective measures, storage of pesticide and micecide were calculated based on results from 13 questions of BRFS questionnaire by weight on age structures from 2000 census. RESULTS: 36.7% pedestrians reported that they had traffic peccancy behavior in the past 30 days with 3.67% as always, 11.3% as sometimes and 21.7% as seldom. 30.3% bicycle riders reported that they had traffic peccancy behavior in the past 30 days. There were 13.2%, 11.4% and 16.9% auto-drivers reported ever having drunken driving, tired driving or driving without license. 7.7% drivers and riders always wore a safety belt. 19.1% motorcycle drivers and riders reported that they wore a crash helmet while riding. The traffic peccancy behavior in males, in rural area was more serious than in females and in urban areas. There were more families preserving pesticide and micecide in rural than in urban areas. 10% of these families did not have a good storage. CONCLUSION: The traffic peccancy behavior was very serious, but the protective measures were not well conducted in China. The storage of pesticide and micecide was unsatifactory. The awareness on safety was insufficient in the general population, suggesting that it is of urgent importance to change people's improper behaviors through health education. It is also important to develop regulations to create supportive environment in reducing the deaths caused by injury.

Accidents, Traffic↗

NDRG2 expression and mutation in human liver and pancreatic cancers.

AIM: To investigate the expression of NDRG2 and mutation of the entire coding region of NDRG2 in human liver and pancreatic cancers, and to further discuss the possible causes of NDRG2 distinct expression patterns. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the expression of NDRG2 mRNA in 37 fresh cancer specimens (including 8 cases of pancreatic cancer and 29 cases of liver cancer) and adjacent normal tissues collected from clinical operation. In addition, mutation analysis of the whole coding region of NDRG2 in these cancers was examined by polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP). RESULTS: Compared with adjacent normal tissues, the expression levels of NDRG2 mRNA in corresponding cancer tissues reduced significantly (pancreatic cancer: 0.680+/-0.112 vs 2.089+/-0.214, P<0.01) (liver cancer: 0.894+/-0.098 vs 1.345+/-0.177, P<0.05). Using PCR-SSCP, the mutation of the whole coding region of NDRG2 was not found in those cancer tissues where the expression of NDRG2 mRNA reduced markedly. CONCLUSION: NDRG2 gene might express differently between normal tissues and cancer tissues, and might play an important role in the development of pancreatic cancer and liver cancer. Low expression of NDRG2 might be unrelated to the mutation of coding region of NDRG2.

Gene Expression Regulation, Neoplastic↗