Aqueous two phase system(ATPS) provides a gentle, non-denaturing separation environment for proteins, enzymes. While high-speed countercurrent chromatography (HSCCC) is a liquid-liquid partition chromatography which uses centrifugal force to hold the stationary phase and facilities the mobile phase partitioning through the stationary phase, it can produce high separation efficiency with large sample loading capacity. However, the ordinary HSCCC apparatus (Type J ) fails to retention a satisfactory stationary phase of ATPS because of its high viscosity and low interfacial tension. Nevertheless, the later designed cross-axis planetary centrifuge system(X-CPC) can produce a greater lateral force field and enhances significantly the retention of the ATPS stationary phase. A review of the application of these CCC techniques with ATPS in the separation of proteins was given. Meanwhile, new techniques such as pH-peak focusing CCC and dye-ligand affinity CCC and some new CCC column design for improvement of separation efficiency and retention of ATPS stationary phase are introduced.

Adult ; Antineoplastic Agents ; adverse effects ; Comet Assay ; DNA Damage ; Female ; Humans ; Nurses ; Occupational Exposure ; Young Adult

Animals ; Animals, Newborn ; Brain Edema ; prevention & control ; Hypoxia-Ischemia, Brain ; prevention & control ; Progesterone ; therapeutic use ; Rats ; Rats, Wistar

BACKGROUND: Bone marrow mesenchymal stem cells (BMSCs) are conveniently cultured and separated in vitro because theirimmunogenicity is low. Therefore, BMSCs are suitable for cell transplantation. Research has shown that BMSCs are potential to repair neurological defect. OBJECTIVE: To determine whether in vitro cultured BMSCs can be transplanted to repair peripheral nerve injury or not, and to investigate its mechanisms. DESIGN, TIME AND SETTING: Randomized controlled animal study This study was performed in Department of Toxicology, Public Health College of Jilin University from March 2006 to March 2007.MATERIALS: Fifty healthy female Wistar rats aging 2 months and six 1-week-old female Wistar rats were used for extraction of BMSCs. Rabbit-anti-nerve growth factor (NGF) monoclonal antibody was provided by Santa Cruz Company. METHODS:BMSCs were separated and cultured with adherent method. In the 3rd generation, BMSCs were preiabeled with bromodeoxyuridine (BrdU) 48 hours before transplantation. Fifty healthy Wistar rats were selected to prepare sciatic nerve crush injury models with clamping method.Subsequently, rats were randomly divided into transplantation group and control group, with 25 rats in each group. Rats in the transplantation group underwent transplantation of BrdU-labeied BMSCs at nerve injured sites; while, the same volume DMEM was injected into rats in the control group. MAIN OUTCOME MEASURES: Injured nerve in the transplantation group suffered from anti-BrdU staining 1, 2, 4, and 6 weeks after surgery. Distal injured nerve in both groups suffered from NGF immunohistochemical staining 1, 2, 4, and 6 weeks after surgery. Image analysis system was adopted to analyze integrated absorbance of positive expression. Gait analysis was performed every week after surgery to measure sciatic nerve function index, and it was also adopted to measure regenerated nerve conduction velocity 6 weeks after surgery. Subsequently, amount and inner diameter of medullated nerve fibers were calculated after luxol fast blue staining, while wet weight of experimental-lateral gastrocnemius muscle and cross section area of muscle fiber were measured at the same time. RESULTS: Fifty rats were included in the final analysis. BrdU-labeled positive cells could be found at injured nerve in the transplantation group 1, 2, and 4 weeks after surgery. Integrated absorbance of NGF protein expression in the transplantation group was significantly higher than that in the control group 1 and 2 weeks after surgery (P < 0.01), but there were no significant differences between the two groups 4 and 6 weeks after surgery (P > 0.05). Sciatic nerve function index in the transplantation group superiorly recovered to that in the control group 3-6 weeks after surgery. Furthermore, 6 weeks after surgery, nerve conduction velocity, amount and diameter of medullated nerve fibers, wet weight and cross section area of gastrocnemius muscle in the transplantation group were significantly higher than those in the control group (P < 0.05-0.01). CONCLUSION: BMSCs can be transplantated into injuried nerve tissue, and promote the recovery of nerve function in the micro-enviroment, improve NGF expression in an early phase may be one of its mechanisms.

Powder X-ray diffraction (PXRD) technology combined with cluster analysis method was used to classify 75 batches of crystalline ceftriaxone sodium into subtypes, the crystalline characteristics of each subtype were measured with scanning electron microscope (SEM). By comparing some parameters of these subtypes correlated to crystallization process of ceftriaxone sodium, such as salification rate, water content in different subtypes, as well as by studying different lattice stabilities, different compatibilities with rubber closures during accelerated stability tests, the key point to improve the quality of domestic ceftriaxone sodium was disclosed. The results of this paper indicated that the fine structure of the products could be controlled well by improving the salification and crystallization process. As a result, the subtype II of ceftriaxone sodium with high stability can be produced.

Objective To study the expression of Stat5,E-cadherin and Vimentin in thyroid carcinoma and the correlation among them. Method The expression of Stat5,E-cadherin and Vimentin in 149 cases of thyroid specimens(including 23 cases of nodular goiter and 126 cases of thyroid carcinoma)was detected by immunohisto-chemistry SP method and the correlation analysis was conducted with the main clinical pathological parameters. Results The positive rate of Stat5 and Vimentin in thyroid carcinoma was 85.71% and 77.78% respectively, which was significantly higher than that in nodular goiter(26.09%and 8.70%)(P<0.05)and the positive rate of E-cadherin in thyroid carcinoma was 25.40%,lower than that in nodular goiter(86.96%)(P<0.05). Three kinds of protein expression were not significantly correlated with gender and age (P > 0.05),but obviously with lymph node metastasis and pathological type(P<0.05). Stat5 was negatively correlated with the expression of E-cadherin (r=-0.335,P=0.000)but positively with the expression of Vimentin(r=0.218,P<0.05). Conclusion The high expression of Stat5 and EMT in thyroid carcinoma tissues indicate that Stat5 may be involved in the EMT process of thyroid carcinoma ,thus it can promote the invasion and metastasis of thyroid carcinoma.

Objective:To study the function of transcription factor 4 (TCF4) and to prepare TCF4 polyclonal antibody.Methods:pET-41/TCF4 was transformed into E.coli BL21(DE3) and induced by IPTG.The purified GST-TCF4 fusion protein was applied to immunize rabbit to produce antiserum. The specificity of the affinity of purified anti-TCF4 antibody was examined by Western blotting analysis of the eukaryotic expressed products of TCF4. Dig-labeled probe and antibody against TCF4 were used to examine the expression of TCF4 in Saos-2 cells under mechanical stretch. Results:Western blotting showed that the antibody could bind to TCF4 specifically. The expression of TCF4 mRNA and protein were significantly increased in Saos-2 cells under mechanical stretch. Conclusion: TCF4 antibody has been prepared successfully.

Objective:To observe the specific cellular immune response and the protection against P815 mastovytoma cells(H 2 d) stable expressing HBV surface antigen and HCV core antigen after the immunized mice(H 2 d) with plasmids SpcDNA3.1,CpcDNA3.1 and chimeric plasmid CSpcDNA3.1.Methods:After subcutaneous immunization with the three plasmids SpcDNA3.1,CpcDNA3.1 and CSpcDNA3.1 respecitively 3 w,the mice were inoculated with the transfected P815 tumor cells.The tumors size and the survival rate were measured.CTL assay was detected with LDH methods.Results:The chimeric plasmid CSpcDNA3.1 could inhibit the tumor growth,prolong the survival period and improve the survivial rate evidently.The splencytes from immunized mice showed strong CTL activity to CSpcDNA3.1 transfected P815 tumor cells.Conclusion:It was suggestd that specific antitumor cellular immunity could be induced by immunization with the chimeric plasmid CSpcDNA3.1 that contain chimeric HBV and HCV gene.

ObjectiveTo investigate the changes of non-linear dynamics characteristics of EEG during picture memory masks, and the application of non-linear dynamic analysis for memory research.MethodsEEGs of 30 healthy old volunteers were recorded under the states of opened eyes and picture memory. Correlation dimension (D2) was calculated for all subjects.ResultsD2 increased significantly during memory tasks compared with the rest state with eyes opened (P<0.05). In different memory tasks, the complexity of mental functions and the regions involved in the memory task were different.ConclusionNon-linear analysis is appropriate for the study of functional changes and working mechanism of brain during memory.

Objective: The inhibition on the proliferation of colorectal carcinoma cell strain with different proliferative potential by ATRA was investigated in present study, which would benefit for the therapy of ATRA on colorectal carcinoma. Methods: The proliferation of LS174T and CW-2 colorectal carcinoma cell strain inhibited by ATRA was determined using cell observation, FACS and MTT methods. Results: The growth speed of LS174T cell strain was faster than that of CW-2. ATRA played a significant role on inhibiting the proliferation of LS174T and CW-2 cell strain and inducting the cell differetiation in vitro. Conclusions: ATRA could inhibit the growth of LS174T and CW-2 cell strain. ATRA could inhibit the proliferation of colorectal carcinoma cell and induce cell differentiation to some extent, which was correlated with the concentration of ATRA.