OBJECTIVETo study the effect of aqueous extract of Taxus chinensis var. mairei (AETC) combined Erlotnib on the growth of A549 xenograft in nude mice and its mechanism.

METHODSThe xenograft model in nude mice was established by inoculating A549 cells subcutaneously. BALB/c nude mice bearing A549 xenograft were randomly divided into six groups, i.e., the low dose Erlotinib group (A) , the standard dose Erlotnib group (B) , the low dose Erlotinib combined AETC group (C), the standard dose Erlotnib combined AETC group (D), the AETC group (E), the control group (F), 12 in each group. Different medication was performed for 7 successive weeks after 24 h. One mL blood was withdrawn and tumor tissues taken. The tumor inhibition rate was calculated. The combined effect was analyzed by Jin's Formula [Q = Ea + b/(Ea + Eb-Ea x Eb) ]. mRNA and protein expression levels of epidermal growth factor receptor (EGFR), cyclooxygenase-2 (COX-2), and B cell lymphoma-2 (Bcl-2) in xenografts were detected using real-time RT-PCR and ELISA.

RESULTSCompared with Group F, the xenograft weight was obviously lowered in Group B-E (P < 0.05, P < 0.01). The q value was 0.92 in Group C and 0.96 in Group D, which was obtained by simple adding of the two drugs. Compared with Group F, EG- FR mRNA expression in Group D and E, COX-2 mRNA expression in Group A-E; Bcl-2 mRNA expression in Group B-D; COX-2 protein expression in Group B-E; Bcl-2 protein expression in Group C and D were obviously lowered with statistical difference (P < 0.05, P < 0.01).

CONCLUSIONSAETC combined low dose and standard dose Erlotinib had synergistic effect on tumor inhibition. Its mechanism might be associated with down-regulating mRNA and protein expression levels of COX-2 and Bcl-2.

Animals ; Antineoplastic Agents ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; pharmacology ; Cell Line, Tumor ; Cyclooxygenase 2 ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Enzyme Inhibitors ; pharmacology ; Erlotinib Hydrochloride ; pharmacology ; Heterografts ; Lung Neoplasms ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Receptor, Epidermal Growth Factor ; metabolism ; Taxus ; Transplantation, Heterologous

A biosurfactant-producing strain(S_6)was isolated from oil-containing wastewater in oxidation ditch and identified as Pseudomonas aeruginosa based on physiological and biochemical experiments and 16S rDNA sequence analysis.Infrared spectrum analysis revealed that S_6 produced glucolipid in the process of metabolism.It was observed that S_6 decreased the surface tension of water from 72 mN/m to 33.9 mN/m with the critical micelle concentration(CMC)of 50mg/L.The measurement of oil displacement and surface tension demonstrated that the fermented liquid had stable surface activity at varying range of salinity,pH,amount of dissolved oxygen.The optimal culture condition was obtained through orthogonal experiment:glucose 10g/L,urea 5g/L,KH_2PO_4 1g/L,liquor of microelement 2mL,pH 8.0,water 1000mL;and the biosurfactant production under optimal culture condition was 0.173g/L.

A new experiment curriculum system of environmental microbiology was established centering on applied microbiology in environmental protection field and emphasizing on design and research experi- ments to motivate the students’ interests for the course, which helped them to improve their ability of think- ing independently and creatively as well as their practicing ability.

The mechanism of chromium accumulation and microstructure transformation of the fused yeast were studied in this paper.The result showed that the process of Cr6+ reduction and adsorption was accom-panied by the H+ consumption.The main adsorptive groups on the strain surface included amino,hydroxyl,phosphate group and amide,among which phosphate group played vital role in the chromium accumulation.The removal rate of chromium and reduction rate of hexavalent chromium declined 70% and 46%,respec-tively,when phosphate group was masked.During the adsorption process the chromium ions complexed on the surface of fused yeast was transported into the cell wall and combined with inclusion to form steady spe-cies and this took 90 min to reach the equilibrium.The biosorption and reduction of Cr on the cell surface would alter microstructure of cell surface,reduce cell membrane potential and increase cell membrane per-meability.

Objective To investigate the therapeutic effect of silencing fibrinogen-like protein 2 (FGL2) gene on acute necrotic pancreatitis (ANP) mice.Methods Eighteen C57/BL mice were randomly divided into SO (sham operation) group,ANP group and Ad-FGL2-siRNA group carrying FGL2 siRNA adenovirus,with 6 in each group.Sodium taurocholate was retrogradely injected into the biliopancreatic ducts of the mice to induce ANP mice model.The mice in Ad-FGL2-siRNA group were injected intravenously in the tail vein with Ad-FGL2-siRNA befor the model establishment.The mice were sacrificed 6 h later,and then the pancreatic tissue and blood were collected.TNF-α and IL-1β expression were measured with ELISA,pancreatic tissue was examined with routine pathological examination,FGL2 mRNA and protein expression were measured with reverse transcription-PCR,western blotting and immunohistochemical staining,and cell apoptosis was assessed by TUNEL method.Results The pathological score of the pancreatic tissue in SO group,ANP group and Ad-FGL2-miRNA group was(1.33 ±0.21),(9.17 ±0.98) and (6.26 ±0.52),respectively.The serum TNF-α level in SO group,ANP group and Ad-FGL2-miRNA group was(63.8 ± 4.2),(240.4 ± 18.6)and(123.0 ± 10.3)ng/L,respectively.The serum IL-1β level was (43.6 ±4.4),(186.6 ± 18.7)and (92 ±10.9)ng/L.The mRNA expressions of FGL2 was 1.20 ±0.22,4.40 ± 1.21 and 2.15 ± 0.56.The protein expressions of FGL2 was 0.33 ± 0.08,1.23 ± 0.24 and 0.68 ± 0.09.The rate of FGL2 positive cells was (2.56 ± 0.31) ％,(15.10 ± 3.23) ％ and (8.68 ± 1.81) ％.The number of apoptotic cells was (4.51 ±1.21),(35.81 ± 4.11) and (11.79 ± 3.02) / × 200HPF,which in the ANP group was higher than that in SO group,and in the Ad-FGL2-siRNA group was significantly lower than that in ANP group and higher than that in SO group.All the differences were statistically significant (all P values ＜ 0.05),except that on the FGL2 mRNA expression between Ad-FGL2-siRNA group and SO group.Conclusions Silencing FGL2 gene may alleviate pancreatic injury in ANP by reducing the release of inflammatory factors and inhibiting cell apoptosis.

0.05); the levels of LL, LI, RRS in CBA group and CBA+IBT group were significantly lower than those in control group(P

Effects of Cr 6+ concentration and culture time on four heavy metal removing strains,stability of these four strains removing Cr 6+,configuration changes inside or outside their cells,effects of Cr 6+ on soluble reductive sugar inside their cells,and effect of several factors on these strains had been studied,and the Cr 6+ resistance mechanisms of these strains have been discussed elementarily. The results showed that the Lethality of these strains caused by Cr 6+ was similar with one another, namely, increasing at first, then decreasing, and finally increasing again as culture time passed. Acclimatization of Candida sp. was better than Sporobolomycetaceae sp.,and the Cr 6+ resistance of Sporobolomycetaceae sp. 7-3 was the best of the four. The research also demonstrated that the metabolic activity of these strains had been influenced by Cr 6+ in a certain extent. Scanning electron microscopy,transmission electron microscopy,and atomic force microscopy observations approved that removal of Cr 6+ by Candida sp. was depended on both surface adsorption and intracellular accumulation. Effects of Cr 6+ concentration, pH, culture time, nitrogen source, carbon source and adsorption time on these strains are not the same.

OBJECTIVETo study the effect of maternal isolation stress on the epilepsy susceptibility in young rats and the possible mechanism.

METHODSSixty Sprague-Dawley young rats were randomly divided into a normal control and two maternal isolation groups that were subjected to maternal isolation for 15 min or 3 hrs daily on postnatal days 2-17. On postnatal day 18, an amygdala kindling test was performed to induce seizures. The expression of GABA(A) receptor α₁ in the hippocampus was determined by immunohistochemisty.

RESULTSThe weights were reduced, the threshold of amygdala kindling and the stimulation number for full kindling decreased significantly, and seizures were more severe in the maternal isolation 3 hrs group compared with the normal control group. The expression of GABA(A) receptor alpha(1) in the hippocampus CA1 area in the maternal isolation 3 hrs group decreased significantly compared with that in the normal groups. There were no significant differences in the aspects above mentioned between the maternal isolation 15 min and normal control groups.

CONCLUSIONSThe stress of early daily maternal isolation for 3 hrs may affect adversely brain development and increase epilepsy susceptibility in young rats. The decreased expression of GABA(A) receptor α₁ in the hippocampus may contribute to the potential mechanism.

Amygdala ; physiology ; Animals ; Disease Susceptibility ; Epilepsy ; etiology ; Female ; Hippocampus ; chemistry ; Kindling, Neurologic ; Maternal Deprivation ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Receptors, GABA-A ; analysis ; Stress, Psychological ; complications

BACKGROUND:Repair programs of posterolateral tibial plateau fracture included posterior plate screws, lateral plate screw and anterior and posterior lag screw fixation. To choose which fixation methods depends on clinical experiences of physicians. Study results are mainly clinical reports, and lack of mechanical evidence.
OBJECTIVE:To compare biomechanical changes in three fixed manners (lateral plate screw group, posterior plate screw group and anterior and posterior lag screw group) in the repair of posterolateral fracture of tibial plateau from the angle of biomechanics.
METHODS:A total of tibial specimens of six adult male antisepsis corpses (12 samples) were used for measuring bone mineral density of metaphysis. 1/2 posterolateral tibial plateau fracture model was established by electric pendulum saw. The model was randomly divided into three groups:lateral plate screw group, posterior plate screw group and anterior and posterior lag screw group. Finite element method and biomechanics were used to test axial displacement value and the maximal displacement distribution area under the axial loads of 250, 500, and 1 000 N.
RESULTS AND CONCLUSION:There was no significant difference in average bone density in three groups of metaphysis (P>0.05). The minimum axial displacement of the fracture fragments was in the anterior and posterior lag screw group (0.013 521 mm), fol owed by posterior plate screw group (0.016 991 mm), and the maximum was visible in the lateral plate screw group (0.138 200 mm) under 250 N load. Displacement value was similar to the 250 N under 500 and 1 000 N. According to the results of biomechanics, displacement values of anterior and posterior lag screw was obviously less than the lateral plate screw group and posterior plate screw group (P<0.05). There was no significant difference between the lateral plate screw group and posterior plate screw group (P>0.05). The maximal displacement distribution area was proximal tibiofibular joint border zone in two methods. These data indicated that the biomechanical stability was most advantageous in the anterior and posterior lag screw group, and poorest in the lateral plate screw group. In the clinic, anterior and posterior lag screw fixation can be used as a first choice for repair of posterolateral tibial plateau fracture.

Objective Lysine-specific demethylase 1 (LSD1) is a flavin adenine dinucleotide-dependent oxidase, which participates in many biological processes , such as cell proliferation and differentiation and gene activation and repression .The aim of this study was to investigate LSD1 acetylation by histone deacetylase inhib -itor trichostatin A ( TSA) and its effect on TSA-induced apoptosis of ovarian cancer cells . Methods LSD1 shRNA was synthesized and implanted into the pLKO-Tet-On lentiviral vector , which was transfected into HO8910 and SKOV3 ovarian cancer cell lines , and then the transfected cells were screened with 1.5μg/mL puromycin for one week until stable clones were established .The cells were treated for 48 hours with methanol (2 mg/mL, control), TSA (200 nmol/L), TCP (100μmol/L), or TSA+TCP.And in the experiment of RNA interfering the LSD1 expression, the cells were also treated for 48 hours with methanol (2 mg/mL, control), TSA (200 nmol/L), Dox (100 ng/mL), or TSA +Dox.The levels of LSD1 acetylation and its substrate histone H3 lysine 4 dimethylation (H3K4me2) were de-tected by immunoprecipitation (IP) and Western blot.The apoptosis of the cells was determined by Annexin Ⅴ/PI staining and flow cytometry, the transcription levels of the Bax and p21 genes detected by real-time quantitative PCR, and the H3K4me2levels in the promoter regions of Bax and p21 measured by chromatin immunoprecipitation ( ChIP ) .Results In comparison with the methanol control, the TSA group showed significantly increased levels of LSD 1 acetylation in the HO8910(1.00±0.29 vs 5.83±0.46, P<0.01) and SKOV3 cells ( 1.00±0.24 vs 5.07±0.35, P<0.01) as well as that of H3K4me2 ( P<0.01);the total apoptosis rates of HO 8910 and SKOV3 cells were remarkably increased in the TSA, TCP, and TSA+TCP groups (P<0.05), even more significantly in the TSA+TCP than in the TSA and TCP groups ( P<0.05) .The mRNA expressions of Bax and p21 in the HO8910 cells were markedly upregulated in the TSA, Dox, and TSA+Dox groups (P<0.05), even more significantly in the latter than in the former two groups (P<0.05).The TSA group exhibited a higher level of H 3K4me2 than the methanol control in the promoters of Bax(2 .92±0.26 vs 0.68±0.19, P<0.01) and p21 (3.07±0.29 vs 0.93±0.17, P<0.01). Conclusion TSA induces the LSD1 acetylation, while suppression of LSD1 expres-sion and activity may enhance the antitumor activity of TSA .