Natamycin is a polyene macrolide antifungal antibiotic ,which is wide ly used in the food industry in order to prevent mould contamination .Biosynthe s is gene cluster of natamycin is discovered by the overall of progress in molecul ar biology of natamycin, including 16 open reading frames which includes the gen e for 26-member ring formation of natamycin (pimS0-pimS4 ) and the modifying gene s, and the function of the protein including polyketide synthases(PKSs)、PimD、P imJ、PimK were studied

ObjectiveTo study the change of autophagy of human pancreatic cancer cell MiaPaCa-2 before and after Ad5-KAI1 tranfection,and to investigate the possible mechanism.MethodsThe MiaPaCa-2 cells without KAI1 expression were infected with Ad5-KAI1 with KAI1 target gene,and Ad5-null was used as negative control,and parental cell was used as blank control.The formation of autophagosomes was observed by electromicroscopy.The green fluorescent protein-labeled light chain 3 (LC3) associations with autophagosome membranes was detected by confocal microscopy.PD98059,LY294002 were applied to pre-treat the cells.The expression levels of beclin 1,AKT,ERK,the phosphorylation of AKT and ERK protein and the ratio of LC3-Ⅱ to LC3- Ⅰ were detected by Western blotting.ResultsAfter 100 MOI Ad5-KAI1 infections for 24 h,the rate of cell expressing KAI1 protein reached (84.97 ±8.56)％,number of LC3 increased from 4 to 20; and swelling,degeneration of mitochondria was observed,and bilayer-like structure in cytoplasm was found.The expression of beclinl increased (1.4 ±0.3 ) folds,and the expression of LC3-Ⅱ/LC3- Ⅰ increased (8.00 ±2.78) folds.PI3K blockade LY294002 pretreatment significantly suppressed the phosphorylation of AKT of MiaPaCa-2 (2.756 vs 1.516),but it did not inhibit the increase of ratio of LC3-Ⅱ to LC3- Ⅰ(0.770 vs 1.403).ERK blockade PD98059 pretreatment not only significantly suppressed the phosphorylation of ERK of MiaPaCa-2 ( 1.637 vs 0.403 ),but also inhibit the up-regulation of beclin 1 protein expression ( 2.377 vs 1.150) and increase of ratio of LC3- Ⅱ to LC3- Ⅰ (2.225 vs 0.680).ConclusionsKAI1 can significantly induce autophagy of human pancreatic cell line MiaPaCa-2 through phosphorylation of ERK rather than AKT.

Objective To explore the pathway of KAI1 induced autophagy regulating apoptosis in human pancreatic cancer cell line MiaPaCa-2.Methods There were three groups in the experiment,which were extracellular regulated protein kinases (ERK) phosphorylation inhibitor PD98059 pretreated group,Caspase-3 activation inhibitor VAD-FMK pretreated group and no PD98059 or VAD-FMK pretreated groups.And each group was divided into three sub groups with different treatment,which were adenovirus AD5-null vector infected control group,the human KAI1 gene recombinant adenovirus vector AD5 KAI1 infected group and autophagy inhibitor 3-MA pretreated and AD5-KAI1 infected group.The cell apoptosis was observed by AnnexinV-FITC/PI double staining.Caspase-3 activation level was evaluated by flow cytometry.ERK phosphorylation and poly(ADPribose) polymerase (PARP) cleavage were determined by Western blot.Results After the cancer cells infected with AD5 KAI1,KAI1 protein was expressed and GFP-LC3 green particles increased.Caspase-3 activation,PARP cleavage,ERK phosphorylation and apoptosis increased obviously.After autophagy inhibitor 3-MA pretreated,the percentage of apoptosis increased from (63.0 ± 7.9)％ to (88.0±4.5) ％ and Caspase-3 activation increased from (34.0±2.8) ％ to (44.2±4.0) ％ and PARP cleavage more.The apoptosis induced by 3-MA could be totally inhibited by Caspase-3 activation inhibitor VAD-FMK pretreated but could not be inhibited by ERK phosphorylation inhibitor PD98059.Conclusion KAI1- induced autophagy inhibits apoptosis through the downregulation of Caspase-3activation and PARP cleavage instead of ERK phosphorylation.

Medical Image has been increasingly applied in clinical diagnosis and treatment.It is very important to make use of large numbers of images in medical image management system in order to help clinician to analyze and diagnose.The traditional information retrieval techniques are not fit for retrieving large scale medical image databases.It is a very promising idea to introduce Content-based Image Retrieval(CBIR) technique into indexing medical image databases.The structure of the Content-based Medical Image Retrieval System(CBMIR) is introduced,and the key problems are mainly investigated,which included image segmentation,feature extraction,similarity searching and feedback mechanism.At last,the status and development of CBMIR are discussed.

Objective To investigate the effects of extractum trametes robiniphila murr combinated with hydroxyurea on proliferation and apoptosis of K562 cells and whether the 2 drugs have synergistic effects,and to detect the antiproliferation and apoptosis ratio of cells in diffe-rent groups were detected.Methods K562 cells were cultured in vitro,and logarithmic phase cells were used for study.MTT-inhibitory test and cell morphological analysis were employed to examine the effects of extractum trametes robiniphila murr alone or in combination with hydroxyurea on proliferation of K562 cells.The effects of extractum trametes robiniphila murr alone or in combinated with hydroxyurea on apoptosis of K562 cells were examined by flow cytometry.The expressions of bcr-abl,bax and bcl-xl mRNA levels were detected by way of reverse transcription polymerase chain reaction(RT-PCR).Results Extractum trametes robiniphila murr could inhibit proliferation and induce apoptosis of K562 cells,and extractum trametes robiniphila murr combinated with hydroxyurea had a synergistic effects on cell prolife-ration and apoptosis.The RT-PCR displayed that either extractum trametes robiniphila murr alone or in combinated with hydroxyurea could down-regulate the expression of bcl-xl mRNA and up-regulate the expression of bax mRNA and the effect of the 2 drugs had a synergistic effect on bcl-xl and bax mRNA expressions.Extractum trametes robiniphila murr alone could also down-regulate the expression of bcr-abl mRNA,but hydroxyurea alone did not show any effect on the expression of bcr-abl mRNA and the 2 drugs had no synergistic effect.Conclusions The effect of extractum trametes robiniphila murr combinated with hydroxyurea on the proliferation and apoptosis of K562 cells has a synergistic effect.The mechanism of antiproliferation and inducing apoptosis of extractum trametes robiniphila murr is probably related to down-regulating the expression of bcl-xl and bcr-abl mRNA and up-regulating the expression of bax mRNA.The synergistic effect of antiproliferation and inducing apoptosis of extractum trametes robiniphila murr combinated with hydroxyurea on K562 cells is probably related to down-regulating the expression of bcl-xl mRNA and up-regulating the expression of bax mRNA.

Objective:To study the effects of 17 beta-estradiol (E2) on the proliferation and metastasis potential of salivary gland mucoepidermoid carcinoma M_3SP_4 cells. Methods:The effects of E2 on the potential of proliferation and metastasis of M_3SP_4 cells were investigated by cell counting, MTT assay, clonegenetic assay, in vivo tumour growth and metastasis assay in nude mice.The expression of VEGF,c-erbB-2,Ki-67 and P16 in M_3SP_4 cells was examined by immunohistochemistry assay. Results:E2 increased the proliferation of M_3SP_4 cells at 10~-10-10~-5 mol/L. E2 at 10~-7 mol/L showed the strongest effects.After treatment with E2 at 10~-7 mol/L,the population doubling time of M_3SP_4 cells decreased by 10.8%,clonegenecity increased by 225%, VEGF,c-erbB-2 and Ki-67 expression increased,P16 decreased.In the in vivo assay,the tumour growth increased by 65% and metastasis increased by 609% in nude mice treated with E2 at 0.005 2 mg/d. Conclusion:E2 may stimulate the proliferation and metastasis potential of M_3SP_4 cells.

Objective:To establish a culture method of human salivary gland epithelial cells and to study their growth characteristics in vitro.Methods:Tissue explant technic was employed to culture human salivary gland epithelial cells in serum free medium (SFM),1∶1 DMEM/F12 and 1∶1 DMEM/F12 containing 25 ml/L fetal boven serum (FBS) respectively.The morphology of the cultured cells was observed by phase contract microscope.The cell growth was studied by cell counting.The cells were identified by HE staining,PAS staining and SP staining.Results:Growth of human salivary gland epithelial cells was observed in primary culture in the three kinds of medium in all 10 cases. The cultured cells were epidermoid, positive for cytokeratin, negative for Vimentin and positive for PAS staining. The cells in SFM could be subcultured for five passages,while only for one passage in the other two kinds of medium.Conclusion:SFM is superior to serum free 1∶1 DMEM/F12 or 1∶1 DMEM/F12 containing 25 ml/L FBS for the culture of human salivary gland epithelial cells.

Objective To compare the biomechanical properties of non-locking compression plate (DCP) and locking compression plate (LCP) in the internal fixation of humeral shaft fracture by means of finite element analysis.Methods Three-dimensional finite element models were constructed to simulate DCP and LCP internal fixation of humeral transverse fracture.The DCP and LCP groups were compared in terms of peak stress on the humeral fracture fragments (MPa),peak stress on the screws (MPa),and overall displacement peak value (mm) under 4 basic loads (bending,shear,torsion and compression).The biomechanical stability was analyzed after fracture fixation.Results The stress tended to concentrate at the connection sites of plate and screws and distributed evenly on DCP.The stress distributed in a gradient manner at the multiple screw holes and tended to concentrated on the central screws on LCP.Under the bending,shear and torsion loadings,the peak stresses on the fracture fragments and screws in the DCP fixation were larger than in the LCP fixation.However,under the compression loading,the peak stresses on the fracture fragments and screws in the DCP fixation were smaller than in the LCP fixation.DCP and LCP had similar trends in displacement.Under the bending,shear and torsion loadings,the overall displacement peak values in LCP fixation were smaller.However,under the compression loading,the overall displacement peak values in DCP fixation were smaller.Conclusions DCP and LCP have similar biomechanical properties to resist bending,shear,torsion and compression.Due to the gradient distribution of stress among the screw holes,LCP is more suitable for patients with comminuted fracture or osteoporosis.Stress distribution is more even in DCP.Surgeons should consider the advantages of both DCP and LCP to achieve better stability.

Objective To investigate the effects of tibiofibula crossing healing on ankle joint movement. Methods A retrospective study was done for seven patients who experienced tibiofibula crossing healing for an average of 30 months (10 to 54 months) from September 1999 to November 2003. There were four left sides and three right sides. Two patients received plate fixation for their open tibiofibula fractures, while the other five intramedullary nailing for their closed fractures. The plantar flexion and dorsiflexion of the ankle were measured at the follow-ups. Results According to the Kofoed' s evaluation system for the ankle joint, six were assessed as excellent and one as good in this series. Tibiofibula crossing healing had an average influence of 6.3 degrees on the dorsiflexion of ankle, but little influence on the normal gait. Five patients reported different extents of discomfortableness at the ankle. Conclusion Tibiofibula crossing healing has a significant influence on ankle cataplasia.

Objective To investigate the clinical manifestations,diagnosis and treatment of restless legs syndrome.Methods 10 cases with restless legs syndrome were analyzed retrospectively and the relative literature were reviewed.Results and Conclusion Patients with restless legs syndrome showed predominant paraesthesia in their lower limbs,and it appeared or became serious during resting and relieved or disappeared after active or passive movements.All patients complain of aggravated symptom in the night,which resulted in sleep disturbance.Restless legs syndrome is often misdiagnosed.The diagnosis of restless legs is based on its characteristic clinical presentation.Levodopa and dopamine receptor agonist were effective.