Polyketides are very large group of natural products with functional and structural diversity.Most of them are produced by microor- ganism and have medicinal activities,including antibiotic,anticancer,antifungal and antiparasitic properties.The researchs in this area have progressed greatly.More and more polyketides are discovered,on the other hand the mechanisms of biosynthesis of those various polyketides are researched more deeply and clearly.The article reviewed the progress of the research in the diversity of polyketide synthases and the mechanisms of polyketide biosynthesise.

Objective To construct and appraise a series of shRNA eukaryotic expression plasmid which contains vary spots of human SKP2 gene.Methods Three pairs of hairpin-like oligonucleotide sequences specific for human SKP2 gene were designed and synthesized. They were cloned into the eukaryotic expression pSIREN-RetroQ plasmid. The recombinated plasmids were confirmed by PCR and sequencing.Results The shRNA sequences were constructed successfully, and could be inserted into the eukaryotic expression vector pSIREN-RetroQ.Conclusions Three shRNA transcripting plasmids pSIREN-RetroQ are successfully constructed, and form a basis for research in cancer gene target therapy against SKP2 gene.

OBJECTIVE:To observe the effects of parecoxib preemptive analgesia combined with postoperative epidural analgesia on hip replacement and immune function. METHODS:Totally 86 patients undergoing unilateral hip replacement selected from Xining Third People's Hospital during Jan. 2014-Jun. 2016 were divided into observation group and control group according to random num-ber table,with 43 cases in each group. Two groups underwent unilateral hip replacement under spinal epidural anesthesia. Observation group was given Parecoxib sodium for injection 40 mg intravenously 30 min before the end of surgery. Control group was given con-stant volume of normal saline intravenously. Both groups were given epidural analgesia pump(Ropivacaine hydrochloride injection 150 mg+Ondansetron hydrochloride injection 16 mg+Dezocine injection 10 mg,added into normal saline to 100 mL)after surgery with dripping speed of 2 mL/h and patient-controlled time of 15 min. The hemodynamic indexes,analgesic effect,T lymphocyte subsets and NK cells levels were compared between 2 groups at different time points as well as the occurrence of ADR after surgery. RE-SULTS:Two patients of observation group and one patient of control group withdrew from the study. Before surgery,there was no sta-tistical significance in MAP and HR between 2 groups(P>0.05);12,24 h after surgery,MAP and HR of control group were signifi-cantly increased and higher than observation group,with statistical significance(P<0.05). There was no statistical significance in MAP and HR of observation group at different time points compared to before treatment;there was no statistical significance in MAP and HR between 2 groups immediately after surgery,48 h after surgery(P>0.05). There was no statistical significance in VAS score between 2 groups immediately after surgery(P>0.05);6,12,24,48 h after surgery,VAS scores of observation group were signifi-cantly lower than those of control group,with statistical significance(P<0.05). There was no statistical significance in CD3+,CD4+, CD4+/CD8+and NK cells levels between 2 groups before surgery(P>0.05). CD3+,CD4+and NK cells levels of 2 groups immediately after surgery,CD3+,CD4+,CD4+/CD8+ and NK cells levels of 2 groups at 12,24 h after surgery,CD3+and CD4+of control group at 48 h after surgery all changed significantly;CD3+,CD4+,CD4+/CD8+and NK cells levels of observation group at 12,24 h after sur-gery were significantly higher than those of control group,with statistical significantly(P<0.05). There was no statistical significance in the incidence of ADR between 2 groups(P>0.05). CONCLUSIONS:The parecoxib preemptive analgesia combined with postopera-tive epidural analgesia shows good analgesic effect for hip replacement patients,keeps their hemodynamics stable and protects immune function to certain extent with good safety.

Objective:To explore side population(SP) cells in human epithelial cells and to observe the expression of the universal stem cell marker ABCG2,epidermal stem cell markers ?6 integrin and ?1 integrin on SP cells.Methods:Epithelial cells were obtained by digesting human skins with Dispase II and Trypsin and stained with Hoechst33342 and PI.The SP cells were analyzed and sorted by the fluorescence-activated cell sorter.Then the expression of ABCG2,?6 integrin and ?1 integrin was analyzed by flow cytometry.Results:SP cells accounted for 0.2%-0.3% of total human epithelial cells.Only a small part of cells expressed ABCG2,integrin ?6 and integrin ?1 of both SP cells and total human epithelial cells detected by flow cytometry.The difference of positive rates between SP cells and total human epithelial cells was not significant.Conclusion:SP cells accounted for 0.2%-0.3% of total human epithelial cells.The difference of positive rates of stem cells marker ABCG2,integrin ?6 and integrin ?1 between SP cells and total human epithelial cells was not significant.

Objective To analyze the clinical,radiological and pathological features of primary leiomyosarcoma of bone and to im-prove the diagnostic level.Methods Totally 6 cases of PLB proved by pathology were collected in our study.The clinical,radiologi-cal and pathological findings were retrospectively analyzed,and combined with the relevant literature to have a comprehensive analy-sis.Results The lesions of 6 patients were solitary,located in femoral (1 case),distal femur (1 case),proximal tibia (2 cases),is-chium (1 case)and humerus (1 case).There was no periosteal reaction in all 6 cases but they all had soft tissue mass,sometimes there may have some mineralization within the tumor.Ill-defined osteolytic bone destruction was detected in 5 patients,while expan-sion of cystic bone destruction was found in the other 1 patients.3 cases had hardened edge,2 cases with adjacent bone cortical thickening.The MR imaging in 5 patients showed iso-intensity signal on T1 WI,a slightly inhomogeneously higher signal on T2 WI and a significant heterogeneously enhancement after injected of Gd-DTPA.Another 1 patient showed a double ring sign,the central area onT1 WI and T2 WI expressed heterogeneous slightly higher signal,the peripheral annular zone was iso-intensity on T1 WI and slightly higher on T2 WI,after injected contrast medium,it was inhomogeneous enhancement.In immunohistochemically,all tumors reacted positively with SMA,3 patients with Desmin and Vimentin positive,2 patients with Ki-67 positive,and there had some scat-tered cells with CD68 positive,but the S-100 were all negative.Conclusion The clinical,radiological and conventional histological manifestations of PLB are not specific.Immunohistochemical and/or ultrastructural analysis who displayed smooth muscle differenti-ation can confirm the diagnosis.

ObjectiveTo investigate whether aldosterone infusion induces glomerular or podocyte injury in rats and to evaluate the effects of eplerenoen (EPL), andodipine (CCB) and telmisartan (ARB) on aldosterone- induced injury. MethodsThirty male Sprague-Dawley rats were divided into 5 groups: control, subcutaneous infusion of aldosterone (1.5 μg/h, ALD group) and aldosterone infusion plus eplerenone (100 mg·kg-1·d-1, EPL group), amlodipine(10 nag·kg-1·d-1 CCB group), telmisartan (3 mg·kg-1·d-1, ARB group), respectively. Systolic blood pressure(SBP) and urinary albumin excretion ratio(UAER) were measured at day 0, 7, 14, 21, 28. Blood samples were harvested to detect plasma angiotensin Ⅱ, plasma aldosterone, serum sodium, serum potassium and serum creatinine at day 28. Glomerular damge was quantified by morphological glomerular injury score (GIS). Immunohistochemistry and RT-PCR were performed to evaluate podocyte lesion, and apoptosis ratio of pedocyte (ARP) in a glomerular cross section was analyzed by TUNEL. ResultsALD infusion progressively increased SBP and UAER compared with CTL (P＜0.01). SBP was significantly reduced in EPL, CCB or ARB-treated animals, meanwhile, UAER was decreased in EPL and ARB group, but not in CCB group. The ALD-infused rats exibited hypernatremia and hypopotassaemia, which were blocked by EPL adminstration but not by CCB or ARB treatment. ARB group had a significant increase in plasma angiotensin Ⅱ compared with ALD, CCB and EPL groups(P＜0.01). The ALD-infused animals developed hyperaldosteronemia compared with CTL, but with no difference of plasma aldosterone among ALD, EPL, CCB and ARB-treated rats. Treatment with EPL prevented an increase of GIS and ARP compared with CCB and ARB (P＜0.05, P＜0.01). Protein and mRNA expression of nephfin was up-regulated in ALD group (P＜ 0.01), but was significantly prevented by EPL treatment(P＜0.01), whereas CCB and ARB therapy had no such effect. Conclusion ALD infusion significantly induces glomerular and pedocyte injury which is blocked by EPL but not by CCB or ARB independently on systemic hemodynamics.

Background and purpose:Bispecific antibody is a special pattern of genetic engineering antibody.It possesses 2 antigen binding sites, one directed at the effecter cells and the other at the target cells which are always the tumor cells.This enables the effecter cells to recruit to the targets efficiently and exert cytotoxic effect.The experiment was aimed to construct the expression vector of anti-CD3?anti-CD19 bispecific antibody, purification and analyzing the activity of the diabody.Methods:Applyed PCR and overlap PCR to construct the expression vector of anti-CD3?anti-CD19 bispecific antibodies, transformed it into E.coli 16C9 for expression.Purified the diabody by His-tag affinity chromatography and confirmed by 12% SDS-PAGE and Western blot.Antigen binding activity of the diabody was analyzed by FACS.Results:The DNA sequence of the expression vector containing anti-CD3?anti-CD19 fragment was comfirmed.The yield of purified diabody was up to 5 mg/L.The molecular weight of diabody was correctly indicated by SDS-PAGE and Western blot.The diabody could specifically bind to CD19+ Raji cells and CD3+ Jurkat cells while competitively inhibit binding of HIT3a and HIT19a to the cells.Conclusion:Successfully constructed the expression vector of anti-CD3?anti-CD19 bispecific antibodies, the diabody acquired by the method could be produced with high level expression and also had high specific affinity with CD19+ Raji cells and CD3+ Jurkat cells.

Objective To observe whether dermal multipotent stem cells (dMSCs) treated with platelet-derived growth factor-AA ( PDGF-AA )could distribute more frequently to the bone marrow in rats of total body irradiation (TBI).Methods Male dMSCs were isolated and 10 μg/L PDGF-AA was added to the culture medium and further cultured for 2 h.Then the expression of tenascin-C were examined by Western blot, and the migration ability of dMSCs was assessed in transwell chamber.The pre-treated dMSCs were transplanted by tail vein injection into female rats administered with total body irradiation, and 2 weeks after transplantation, real-time PCR was employed to measure the amount of dMSCs in bone marrow.Non-treated dMSCs served as control.Results PDGF-AA treatment increased the expression of tenascin-C in dMSCs, made (1.79 ± 0.13) × 105 cells migrate to the lower chamber under the effect of bone marrow extract, and distributed to bone marrow in TBI rats, significantly more than ( 1.24 ± 0.09) ×105 in non-treated dMSCs (t = 8.833, P ＜ 0.0l ).Conclusions PDGF-AA treatment could enhance the migration ability of dMSCs and increase the amount of dMSCs in bone marrow of TBI rats after transplantation.

Objective To evaluate the value of lymphoscintigraphy in diagnosis of chylous ascites in children.Methods Lymphoscintigraphy was done in 6 cases,computed tomography(CT) was done in 4 cases,X-ray exam was done 42 times.And their video repore were compared.Results Lymphoscintigraphy was done in 6 cases,5 cases′ results were positive which diagnosed chylous ascites,and their leaking positions were also found.Conclusion Lymphoscintigraphy has the qualitative and orientational effect on diagnosis of children with chylous ascites.

Objective To investigate the effect and clinical value of preoperative chemotherapy on the treatment of metastasized lymph nodes in patients with advanced esophageal carcinoma. Methods We studied the pathological results of primary lesions and lymph nodes of 97 patients with advanced esophageal cancer between 1996 and 1999,62patients were treated by preoperative chemotherapy and 35 patients were treated by surgery only. Results The metastasized rate and degree of mediastinum in preoperative group were 16. 1％ and 4.7％ ,whereas 65.7% and 34.2% in the surgery only group (P＜0. 05);That of abdomen in preoperative group were 25.8％ and 6.6％ ,whereas 48. 6％and 12.0％ in the surgery only group (P＜0.05). Conclusion Preparative chemotherapy is effective not only against the primary lesions but also the metastasized lymph nodes. The lower complete response rate of the metastasized lymph may account for the unsatisfied long-term results. Whole resection of primary lesions and lymph nodes are still very important for a better prognosis even for patients who have a good response for the preoperative chemotherapy.