Objective: The metaanalysis aims to estimate the prevalence of suicide plan among college students in mainland China, and to provide more clues and reference for control and prevention of suicide. Methods: The relevant studies were systematically searched via electronic databases (PubMed，Embase，CNKI，Wan Fang Data，VIP). We only selected original articles that either reported on Chinese retrieval words of "college students" "undergraduate" "university" "college" "colleges and universities" "suicide plans" "detection rate" "prevalence" "report rate", and the English retrieval words of "undergraduate" "college" "university" "suicide" "suicidality" "suicide plans" "suicidal plans suicide intending" "prevalence" "report rate" "detection rate" "China" "Chinese". And Stata 12.0 software was used to make a metaanalysis of the data. Results: A total of 18 eligible studies, with 47 071 college students, were finally included. The maximum and minimum reported prevalence of suicidal plan among college students in China mainland was 4.4%(95%CI: 3.4%-5.4%).Subgroup analyses showed that the pooled estimate of suicidal plan of boys(5.4%) was higher than girls’(4.2%); The prevalence among college students from earth, middle and west areas were 5.1%，2.7%，4.5%, respectively; The prevalence among college students in 2010 and after (4.4%)was higher than that before 2010(4.3%), The prevalence among college students of life time suicide plan (4.9%)was higher than that during the past 12 months(4.0%), but there was no statistical significance in the subgroup(P>0.05) . Sensitivity analysis suggested that the results of metaanalysis were relatively stable, while funnel plot analysis suggested that publication bias might exist. Conclusion Prevalence of suicidal plans among college students in mainland China is respectively low, and there was no statistical significance in gender, region, the period of time and simple size.

A method of ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry ( UPLC-Q-TOF MS) was developed to determine 35 kinds of illegally added chemical fungicides in pesticide formulations. The samples were pretreated based on the ultrasonic extraction by the solvent of methanol, and then separated on a Zorbax C18(100 mm×1. 8 mm, 2. 1 μm) column by a gradient elution with 0. 1% formic acid aqueous solution and acetonitrile as the mobile phase. The mass spectrometer was operated under positive mode. Under the optimal conditions, the recoveries at three spiked levels (0. 2, 0. 4, and 2. 0 mg/kg) were in the range of 81. 0%-101. 3% and the RSDs were 1. 0%-4. 4%. Based on the developed method, 100 samples were analyzed, and among which 6 samples were screened out chemical fungicides. The proposed method was high-efficient, accurate and reliable for the qualitatively screening of illegaly added chemical fungicides.

BACKGROUNDMatrix metalloproteinase-9 (MMP-9), endostatin (ES) and vascular endothelial growth factor (VEGF) are important angiogenic regulators for many neoplasms. The aim of this study is to judge clinical and prognostic values of detection of serum MMP-9, ES and VEGF in patients with non-small cell lung cancer (NSCLC).

METHODSSerum levels of MMP-9, ES and VEGF were detected in 92 patients with NSCLC, 50 patients with pulmonary benign disease and 52 healthy controls by ELISA method.

RESULTSThe serum levels of MMP-9, ES and VEGF in NSCLC patients were significantly higher than those in patients with pulmonary benign disease and healthy controls (P=0.000, P=0.000, P=0.000). The sensitivity and specificity of serum MMP-9 was 92.51% and 79.10% with a cutoff value of 117.17 μg/L, 88.32% and 74.25% for ES with a cutoff value of 100.31 μg/L, and 83.40% and 75.63% for VEGF with a cutoff value of 380.32 ng/L. Serum MMP-9 and ES levels were significant prognostic factors for lung cancer patients (P=0.0145, P=0.008). The change of serum MMP-9 level after chemotherapy was a useful indicator of prognosis for NSCLC patients (P=0.0322).

CONCLUSIONSThe serum levels of MMP-9, ES and VEGF are significantly increased in patients with NSCLC. They might be used as prognostic parameters in patients with NSCLC.

BACKGROUNDWith the development of antibody technology, more and more immunoconjugates are used in clinical treatment for different cancers. The aim of this study is to investigate the inhibitive effects of 5F11-DOX immunoconjugate on human lung adenocarcinoma cell line LTEP-A2 in vitro and in vivo and to explore the potential mechanism.

METHODSThe 5F11-DOX immunoconjugate was produced by diluted glutaraldehyde crosslinking. The killing efficiency of 5F11-DOX was detected by clonogenic assay. The distribution of DOX was observed under fluorescence microscope and the 5F11 location was determined by immunohistochemistry. The therapeutic efficacy of 5F11-DOX and free DOX was detected on subcutaneous or intraperitoneal exnogenic transplanted tumors of human lung adenocarcinoma A2 cells in nude mice.

RESULTS5F11-DOX of 0.04mg/L could kill all the A2 cells in vitro and the killing efficiency was 10 times as that of the free DOX. Fluorescence microscopy showed that fluorescence of DOX in 3mg/L 5F11-DOX group was much stronger than that in 3mg/L free DOX group after treating A2 cells with 3mg/L 5F11-DOX or DOX for 3h, then incubating the cells with fresh medium for another 24 hours. Immunohistochemistry showed that 5F11 located in cell membrane and cytoplasm and fluorescence microscopy proved that DOX located inside the cells. The average sizes of subcutaneous or intraperitoneal exnogenic transplanted tumors in 5F11-DOX group were obviously smaller than those of the control group and free DOX group at the same dosage (P < 0.05), and the anti-tumorogenicity efficacy of 5F11-DOX was 4-8 times as that of free DOX. The HE staining showed that extensive necrosis occurred in the center of tumors and around cancer nests in 5F11-DOX group.

CONCLUSIONSThe killing efficacy of 5F11-DOX on human lung adenocarcinoma cell line A2 is obviously higher than that of the free DOX.

BACKGROUNDCytochrome P450 2A6 (CYP2A6) plays an important role in oxidation of nicotine and in activation of tobacco-related carcinogens. It has been suggested that individuals with defective CYP2A6 allele are at a lower risk of developing lung cancer. This study is to investigate the frequency of CYP2A6 gene deletion and the relationship of CYP2A6 genetic polymorphism with lung cancer risk in Chinese.

METHODSA case-control study which detected CYP2A6 genotype of 180 patients with lung cancer and 224 controls by PCR-based genotype assay was conducted.

RESULTSNo relationship was found between the frequency of CYP2A6 gene deletion and lung cancer risk. There was only one case of CYP2A6 del/del genotype in the controls. The frequency of CYP2A6 del allele was 13.8% in the controls, and 12.8% in lung cancer cases. The CYP2A6 del/del genotype was not found in lung cancer cases.

CONCLUSIONSThere is no difference in frequency of CYP2A6 gene deletion between lung cancer cases and controls.

BACKGROUNDTo investigate the relations between metabolizing enzymes' genetic polymorphism and lung cancer risk in Chinese, especially in heavy smokers.

METHODSCYP1A1, 2D6, 2E1 and GSTM1 genotypes were detected in 180 patients with lung cancer and 224 controls by PCR-based genotype assays.

RESULTSCYP1A1 variant allele, CYP2D6 wild allele, CYP2E1 A genotype, GSTM1-null genotype were found to be associated with lung cancer. The individuals who carried GSTM1-null genotype and one of the CYP1A1, CYP2D6, CYP2E1 'in risk' genotypes had a 2.24-2.69 fold increased risk of lung cancer. The heavy smokers had a significantly increased risk of lung cancer than the non-smokers who carried the same genotype of metabolizing enzymes. The heavy smoker who carried all the four 'in risk' genotypes of metabolizing enzymes had an obviously increased risk of lung cancer (OR=9.85, 95%CI=2.30-45.71).

CONCLUSIONSThe individuals who carry the 'in risk' genotype of metabolizing enzymes have an increased risk of lung cancer. It is positively associated with tobacco carcinogen dose.

BACKGROUNDTo study the inhibition effects of both extraneous right sense and antisense p53 on malignant phenotype of human lung cancer cell line.

METHODSThe named 801D cell line with p53 deletion and mutation at 248 code was selected as a model in vitro. The recombined plasmid pEGFP-p53(RS) and pEGFP-p53(AS) were constructed. The extraneous gene was detected by PCR. The p53 mutation protein was examined by immunohistochemical stain of p53 antibody. The inhibition effect of extraneous p53 on tumor growth in vitro were determined by clonogenic survival assay. FCM analysis was carried out in cells. The inhibition effect on malignant growth of extraneous p53 in vivo was observed by heteroplastic transplant on nude mouse.

RESULTSThe transfected cell lines, pEGFP-p53(AS)-801D, pEGFP-p53(RS)-801D and pEGFP-801D were established. Presence of extraneous p53 and neo genes in pEGFP-p53(AS)-801D and pEGFP-p53(RS)-801D was proved by PCR and green fluorescence was found out in those cells under the microscope. Mutant protein in pEGFP-p53(AS)-801D was negative by immunohistochemical stain. The malignant growth of these transfected cell lines was inhibited comparing with parents in vivo and in vitro. Inhibition rate of colony formation was 62.0% for pEGFP-p53(AS)-801D and 80.8% for pEGFP-p53(RS)-801D. The tumorigenicity in nude mice was suppressed. Inhibition effects of extraneous right sense p53 on malignant growth of 801D was more distinct. FCM analysis showed that pEGFP-p53(AS)-801D cells were arrested at G1 phase.

CONCLUSIONSThe transfected cell lines with extraneous right sense and antisense p53 appear that malignant growth can be inhibited in vivo and in vitro.

BACKGROUNDTo construct and express a phage display library of anti human lung cancer monoclonal antibody 5F-11.

METHODSImmunoglobulin variable regions (VH,VL) were amplified from 5F-11 hybridrom by RT-PCR. ScFv genes consisting of VH DNA and VL DNA joined together by a linker DNA were cloned into a phage vector pCANTAB5E. After 4 rounds of screening with lung adenocarcinoma cell line A2 as antigen, an enriched secondary phage display library was obtained.

RESULTSA recombinant phage display library with total of 8×10⁷ pfu/ml was established. Randomized clones from unselected library digested with BstNⅠ showed different patterns, however, those from selected library showed that phages with special pattern were enriched. Twenty-three out of 30 clones were found to respond strongly to A2 cell lines.

CONCLUSIONSThe ScFv of anti-lung adenocarcinoma monoclonal antibody 5F-11 can be successfully produced, which may be useful to widen the application of the antibody.

BACKGROUNDTo study the effects of extraneous p53 antisense RNA on malignant growth and sensitivity to cisplatin of human lung cancer cell line.

METHODS801D cell line with p53 deletion and mutation at 248 codon was selected as a parent cell line. An 1.8 kb human p53 full length cDNA was inserted into a mammalian expression vector PEGFP to construct a p53 antisense RNA recombined plasmid PEGFP-p53(AS) and GFP gene at plasmid was a report gene to monitor extraneous gene expression. The extraneous gene was detected by PCR. The p53 mutation protein was examined by immunohitochemical stain of p53 monoclonal antibody. The inhibition growth efficacy of extraneous p53 in vitro was determined by clonogenic survival assay. Sensitivity of cells to cisplatin was examined with MTT assay. FCM analysis was performed to measure the effect of p53 antisense RNA on cell cycle.

RESULTSTwo cell lines, PEGFP-p53(AS)-801D and PEGFP-801D, were established after transfection of 801-D cells by lipofection and selection. Presence of extraneous p53 gene in PEGFP-p53(AS)-801D was proved by PCR and expression of extraneous p53 was estimated when green fluorescence in those cells was found out under the fluorescent microscopy. Mutated p53 protein in parent cell line 801D was positive and in PEGFP-p53(AS)-801D was negative with immunochemical stain. The inhibition rate of colony formation was 61% for PEGFP-p53(AS)-801D (P < 0.001). The sensitivity of PEGFP-p53(AS)-801D cells to cisplatin was increased. FCM analysis showed that the cell line was arrested at G1 phase.

CONCLUSIONSp53 mutation at 248 code plays an important role on malignant growth and resistance to cisplatin of human lung cancer cell line 801D. Malignant growth of cells with p53 deletion and mutation at 248 codon can be inhibited by extraneous p53 antisense RNA, and simultaneously the sensitivity to cisplatin is also increased.

Objective　To evaluate the inhibition effect of immunoconjugate of doxorubicin(DXR) with a monoclonal antibody, 5F11 on human lung cancer cells and its reversal effect on resistant lung cancer cells to chemotherapeutic drug. Methods　DXR was attached to 5F11 using dilute glutaraldehyde crossing.The antitumor activity of immunoconjugate, 5F11-DXR, against the sensitive antigen-positive cell line, A2, drug-resistant antigen-positive cell lines, 801-D and 801-DDXR, and antigen-negative cell line, ascite cancer cell was evaluated by human tumor cell cloning assay and dye exclusion assay. Results　According to the results of various assays, comparing with single DXR, 5F11-DXR could significantly increase the cytotoxicity to A2, 801-D and 801-DDXR cell lines with a DXR concentration of 0.4*!μg／ml(P＜0.05), and this difference was even more distinct to A2 cell line with lower concentration of DXR (0.04*!μg/ml). However, there was no remarkable difference between 5F11-DXR and single DXR in cytotoxicity to antigen-negative ascite cancer cell(P＞0.05). Conclusion　5F11-DXR can remarkably increase the cytotoxicity of DXR to the sensitive target cells and even effectively reverse the drug-resistant cell lines to DXR. There is no significant difference between 5F11-DXR and DXR in killing antigen-negative cancer cells.