Objective:To study the in vitro bacteriostasis of water extract of humulus. Methods:By using double dilution method and 96-well plates trace broth dilution method, the inhibitory test of water extract of humulus was conducted on Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The minimum inhibitory concentration ( MIC ) , minimum bactericidal concentration ( MBC) and the diameter of inhibition zone were determined. Results: The drug showed different sensitive degree on the test strains. MIC and MBC for Escherichia coli were 31. 25 mg·ml-1 , that for Staphylococcus aureus were 3. 91 mg·ml-1 , and that for Pseudo-monas aeruginosa was 125 and 250 mg·ml-1 . Conclusion:With the water extract of humulus as the research object, the study on the in vitro bacteriostasis effect of humulus scandens is closer to the clinical application form, which provides reference for the further re-search on the related preparation of humulus scandens.

Objective:To optimize the extraction process of antitumor active ingredients in fructus ligustri lucidi. Methods:Using fructus ligustri lucidi medicinal herb as the raw material, the extraction process of luteolin and pelargidenon in the herb was screened by D-optimal design. The extraction yield of different extraction processes was compared to obtain the optimal extraction conditions. Re-sults:The best extraction conditions were as follows:adding 12-fold 95% ethanol, extracting 2 times with 60 minutes for each time. Conclusion:The optimal extraction technology can provide significant reference for the further pharmacodynamic effect development of fructus ligustri lucidi.

Objective To investigate the characteristics of cisplatin resistance in human gastric cancer cell line SGC-7901 . Methods Single cell gel electrophoresis ( SCGE ) was used to measure the level of DNA damage and repair in gastric cancer cell line SGC-7901 and gastric cancer cisplatin resistance cell line SGC-7901/DDP by ob-serving the tail length. Morphological changes of SGC-7901 and SGC-7901/DDP were recorded to evalutate the differences between the two lines. The degree of migration of SGC-7901/DDP and SGC-7901 measured by cell wound scratch assay was used to estimate the ability of invasion. MTT assay was performed to determine the drug sensitivity, IC50 values and cross-resistance of SGC-7901/DDP treated with 5-FU, VP-16, ADM, TAX and LOHP separately. Results The level of DNA damage and repair in SGC-7901/DDP was higher than that in SGC-7901 ac-cording to the tail length of SCGE tests ,suggesting the relationship between cisplatin resistance and the abiity of DNA damage and repair. There was a much smaller volume in SGC-7901/DDP compared with SGC-7901,and clone aggregation always appeared in SGC-7901/DDP. Cell wound scratch assay showed that the migration of SGC-7901/DDP was weaker than that of SGC-7901. MTT showed the significant increase of IC50 and cross resitance in SGC-7901/DDP compared with SGC-7901 treated with 5-FU, VP-16, ADM, TAX and LOHP simultaneously. Conclu-sion The ability of DNA damage and repair in gastric cancer cisplatin resistance cell line SGC-7901 is enhanced significantly. The SGC-7901/DDP shows a notable promotion on multidrug resistance in vivo, and the migration of SGC-7901/DDP is weaker than that of SGC-7901 .

Recent related researches pointed out that a series of adverse reactions may occur when homocysteine (Hcy) level exceeded normal range .More and more studies indicated that Hcy level abnormal elevating was an inde‐pendent risk factor for cardiovascular diseases .This article summarized its related research situation .

Objective:To comparatively analyze the effect of different methods on the content determination of baicalin in Qing-houyan mixtures. Methods:The content of baicalin in Qinghouyan mixtures was quantitatively determined by orthogonal function spec-trophotometry and HPLC method, respectively. Results: The regression equation of the proposed method was obtained as follows:P2 =0. 091 7C-0. 005 9(r=0. 999 9). The linear relationship was good within the range of 0. 045-0. 225 mg/ml. The determina-tion results had no statistical difference from those of HPLC(P>0. 05). Conclusion:The orthogonal function spectrophotometry meth-od is simple, fast and efficient, which can be applied in the determination of the main active components in traditional Chinese medi-cine preparations.

Objective:To compare the content of icariin in Rujiling granules before and after the ray irradiation. Methods: The column was Thermo ODS-2 HYPERSIL (250 mm × 4. 6 mm,5 μm) with the temperature of 30℃, and the mobile phase was acetoni-trile-0. 033 mol·L-1 potassium dihydrogen phosphate(30∶70) with the flow rate of 1. 0 ml·min-1. The detection wavelength was 265nm. Results:There was a good linear relationship within the range of 3. 44-34. 40μg·ml-1 for icariin (r=0. 999 7, n=6). The average recovery was 98. 18% with RSD of 0. 32%(n=9). Conclusion:The content change of icariin in Rujiling granules before and after the ray irradiation is not statistically significant, which illustrates that the conventional dose irradiation has little effect on icariin.

BACKGROUND:5-Fluorouracil occupies an important position in the treatment of gastric cancer, but its long-term use can easily induce adverse reactions such as myelosuppression and leukopenia. Polylactic acid and its copolymers have a higher biocompatibility, and their decomposer cannot gather in the body.
OBJECTIVE:To investigate the in vitro cytotoxicity mechanism of 5-fluorouracil-loaded polylactic acid nanoparticles on gastric cancer cel lines.
METHODS:Ten mice were selected in this study. 5-fluorouracil-loaded polylactic acid nanoparticles (1×10-7, 1×10-6, 1×10-5, 1×10-4 mol/L) were prepared using ultrasonic emulsification method. Kiling effect of polylactic acid nanoparticles on gastric cancer cel lines in vitrowere detected. Then, the inhibition rate was calculated at different concentrations.
RESULTS AND CONCLUSIONS: Under the transmission electron microscope, 5-fluorouracil-loaded polylactic acid nanoparticles had good shape and relatively evenly distributed with no adhesions. After drug administration, the drug concentration was 50% at 24 hours and 62.9% at 72 hours. After 48 hours co-culture with single 5-fluorouracil or 5-fluorouracil-loaded polylactic acid nanoparticles, the viability of gastric cancer cels showed a decrease trend with the increase of drug concentrations, and moreover, 5-fluorouracil-loaded polylactic acid nanoparticles had a better cel inhibition ability than the single 5-fluorouracil (P < 0.05). The IC50value of 5-fluorouracil-loaded polylactic acid nanoparticles was significantly lower than that of 5-fluorouracil (P < 0.05). These findings indicate that polylactic acid nanoparticles as good drug carriers have a strong drug loading capacity and increase drug concentration in the body, but cannot reduce the biological activity of 5-fluorouracil, which provide new ideas for the treatment of gastric cancer.

Objective To discuss the correlation between procrastination and the mentalities of anxiety and depression among medical postgraduates,so as to carry out mental health work effectively.Methods 423 medical postgraduates in Central South University were assessed randomly, using General Procrastination Scale (GPS),Self-rating Anxiety Scale(SAS),Self-rating Depression Scale (SDS).Results Procrastination score and incidence in medical postgraduates was 54.92±8.40 and 60.99%respectively,the differences of procrastination scores(53.3l±8.21,55.90±8.30,55.75±8.49,P=0.013)and incidences(52.60%,66.09%,65.58%.P =0.028)among three grades were statistically significant.Both total coarse score of anxiety and that of depressionwere higher than that of the whole country(31.24±7.40,29.78±10.07,P=0.000;34.8±8.11,33.46±8.55,P=0.000),the differences were statistically significant.Procrastination had a positive correlation with anxiety and depression significantly(r=0.304,P=0.000;r=0.369,P=0.000),the higher the grade was,the weaker the intensity of correlation was.Hish-delay group,low-delay group and normal-behavior group had different deglees of anxiety(46.63±10.55,44.01±10.12,38.32±7.57,P=0.000)and depression(51.45±10.12,47.81±10.78,40.69±8.23,P=0.000),which was statistically significant.Conclusion Anxiety and depression among medical postgraduates were outstanding and had a close relationship with procrastination behavior,which should be taken seriously and handled by strengthening mental health education.

Objective To construct short hairpin RNA (shRNA) expression plasmids against the inhibitor of differentiation 2 (Id2) gene and establish a suitable cell model for the role of Id2 in proliferation and differentiation of human Ewing sarcoma cell.Methods Three shRNA sequences targeting Id2 gene were designed and inserted into the pGPU6/GFP/Neo (-shRNA-Id2) expression vectors.The recombinant pGPU6/GFP/Neo-shRNA-Id2 plasmids were introduced into Ewing sarcoma RD-ES cells by liposome-mediated transfection.The knock-down efficiency of Id2 in infected RD-ES cells was verified by Western blot assay.The cell growth and cell cycle changes were evaluated by cell counting and flow cytometry between transfected cells and control cells.Results The Id2 expression decreased 54 ％ and 57 ％,respectively,in RD-ES cell line which were transfected with the shRNA-Id2-543 and shRNA-Id2-593 plasmids compared with the control group cells by Western blot analysis.The cell growth assay demonstrated that the cell number in transfected cells was significantly decreased during 6-7 d compared with the control group (P ＜ 0.05).The cells at the S-phase of cell cycle were increased [(36.60±1.53) ％ and (44.89E2.46) ％ vs (29.73±2.03) ％,P ＜ 0.05],and no significant changes at the G2 phase or even reduction in the transfected cells.Conclusions Id2 stable knock-down cell lines are successfully established.The reduced expression of Id2 is related with decreased cell growth and cell cycle arrest in the S-phase.Id2 maybe plays an important role in proliferation of Ewing sarcoma cell.

Objective:To investigate the volatile constituents in Folium isatidis. Methods:The volatile constituents from Folium isatidis were analyzed by head-space solid micro-extraction coupled with GC-MS for the first time. Results: Thirty-five compounds (89. 95%) were identified from the volatile constituents in Folium isatidis. The main volatile constituents of Folium isatidis were 6, 10, 14-trimethyl-2-pentadecanone (6. 32%), nonanal (5. 99%), phenethyl isothiocyanate (5. 79%) and palmitic acid (5. 62%). Conclusion:Palmitic acid and benzyl alcohol may be the main effective constituents in Folium isatidis.