Objective To construct a voxel mouse model combining with Monte Carlo method used for radiation dose calculation.Methods A set of slice images obtained from a nude male mouse (28 g) was utilized, all slice images were registered,some organs or tissues were identified, segmented and filled with specific color, and finally the physical property was defined by MCNP application.Results A mouse model with a voxel size of 0.2 mm×0.2 mm×0.2 mm, consisting of 14 organs or tissues,was constructed, which could satisfy the requirement of precision for radiation dose distribution calculation and moderate computing time.Conclusion The voxel mouse model can be used to calculate the quantity of ionization radiation dosimetry in related areas including radiological medicine, nuclear medicine and space radiation medicine.

Objective To establish a calcification mode in vitro of human vascular smooth muscle cells (HVSMCs) induced by β-GP. Methods Primary HVSMCs were obtained from human embryo by plant method and confirmed by stain with α-sm-actin antibody. The cells after 4-6 passages were divided into two groups.The control group was incubated with normal DMEM medium while the calcification group was incubated with the medium containing 10 mmol/L β-glycerophosphate for 10 days.Calcification was confirmed by alizarin red S stain and alkaline phosphatase(ALP) assays. Results The primary cells observed by S-P stain were positive and the cells after being stained were pale yellow. After being induced with β-GP, the cells of calcification group began concentric growth and formed vesicles. Alizarin red S staining showed that the reaction of calcifying nodules was red,ALP activity was higher than that of controls at various time points(4 d,6 d,8 d and 10 d,P＜0.01 ).Conclusion The HVSMCs could be induced into calcification in vitro by β-GP, and this model contribates to further studies of vascular diseases.

Objective To establish a method of isolation, purification, primary culture and identification of alveolar type Ⅱ epithelial cells(AT-Ⅱ).Methods The AT-Ⅱs were isolated from Wistar rats by trypsin,purified by differential centrifugation, erythrocyte spallation, differential adherence and immune adherence, and identified by observing the morphology of cultured cells under the inverted phase and tannic acid staining. Results and Conclusion The cultured primary AT-Ⅱs in vitro presented single or island form growth, and their shapes were round or elliptical. A great deal of fine particles showed sharp contrast, and were observed in intracytoplasm. The cell nuclei were clear. They were positive for tannic acid staining.The primary culture AT-Ⅱs obtained from improved isolation and purification have good growth state and purity, and are suitable for research in vitro.

Objective To establish a method for culturing neonatal mice cardiomyocytes, and construct an in vitro model of cardiomyocytes for assessing the cardiac toxicity of chemicals. Methods Hearts of neonatal mice of 1 day old were digested with enzyme mixture of trypsin/collagenase type Ⅱ/dispase and the cell suspensions were pre-plated to flask for a short time and then seeded on coated dishes. The cultured cells were treated with 5-fiuorine-deoxy-uridine(15 μg/ml)and uridine(35 μg/ml)to enrich cardiomyocytes that were identified according to the morphology and immunocytochemistry of α-actin antigen. Cardiac myocytes were incubated with 0-64 μg/ml of a fusarium mycotoxin butenolide(BUT) for 12 h. Cell viability was then evaluated by MTT assay. Microscopic observation showed that BUT induced significant morphological changes including cellular swelling, vacuolation and breakage of muscle fibers. Results It was found that 96% of the cultured cells were cardiomyocytes and the myocytes kept beating after 90 days of culture. Concentration-dependent decreases in cell viability following exposure of cardiac myocytes to BUT were observed. Conclusion The results indicated that relatively pure primary culture of neonatal mice cardiomyocytes is successfully established. BUT possesses the potential to induce myocardial toxicity.

Objective To investigate the endurance or resistance of different bacteriophages to bubbling stress in different sampling solutions,to select the optimum sampling solution from three different ones and to select relatively stress-resistant bacteriophages from five different ones.Methods AGI-10(all glass impinger)was used as the representative for all the impingers that would bubble during operation to fulfill the bubbling experiment.Three different sampling solutions used,such as distilled water(DW),phosphatic buffer solution(PBS),and suspension medium(SM),were divided into two groups by adding olive oil(50 μl) or otherwise(0 μl).The impingers were operated 30 min at a flow rate of 7.0 L/min.The titers of bacteriophages and the volume of final sampling solutions were determined before the corrected survival probability was used to evaluate the stress resistance of several different bacteriophages.Results It was found that the survival probability of the same bacteriophage bubbling with different sampling solutions was different except for bacteriophage F2.The use of SM as the collection fluid was related to a high survival probability which remained unchanged between 50 μl and 0 μl olive oil.The corrected survival probability was 79%,77%,86%,50% and 71% for phage SM701,SM702,PhiX174,EcP1 and F2 respectively after 60 minutes of impingement at a flow rate of 7.0 L/min.Conclusion The endurance or resistance of different kinds of bacteriophages in the same sampling solution is different.SM might be an optimum sampling solution for phages.Bacteriophage SM701,SM702 and PhiX174 are more resistant to bubbling stress than EcP1 and F2.

Objective: To observe the effects of microwave on the activity of SOD and the contents of MDA in renal cortex and testis of mice. Methods: Microwave generator(2 450 MHz, 10 mW/cm2) was used to expose mice; NBT,DTNB and TBA were used to mearure the activity of SOD and the contents of MDA in renal cortex and testis of the mice after microwave exposure.Results: The content of MDA in renal cortex and testis of the mice increased progressively on days 1,6,12 and reached the highest level on day 24 after the microwave exposure (P<0.01). The activity of SOD in renal cortex and testis of the mice decreased progressively on days 1, 6, 12 and reached the lowest level on day 24 after the microwave exposure (P<0.01). Conclusions: Microwave exposure can produce reactive oxygen free radicals and lead to depress SOD activity.

Objective:To investigate the molecular interaction between non-structural protein 3 serine protease of hepatitis C virus(HCV)and wild type P53,and to lay the basis for elucidating the mechanism of oncogenesis of hepatocellular carcinoma(HCC)after infection of HCV.Methods:The recombinant plasmids,pGAD424-NS3,pGAD424-NS315aa- and pGAD424-NS330aa-,were constructed and the interaction between NS3 serine protease and its cofactor NS4A,the interaction between wild type P53 and NS3 serine protease and its N-truncated mutants were dectected qualitatively and quantitatively in yeast two-hybrid system.Results:The results indicated that interaction existed not only between full-length NS3 serine protease and P53,but also between N-truncated mutants of NS3 serine protease and P53.Furthermore,the difference between enzyme activity unit(IU)of β-gal induced by these interactions was not significant(P>0.05).Conclusions:NS3 serine protease of hepatitis C virus and its N-truncated mutants can interact with wild type P53,and the region of NS3 serine protease involved in the interaction may be located in its C-terminal,but not in its N-terminal.

Objective:To compare the two-dimensional electrophoresis(2-DE) maps of rat spinal cord protein extracted by two different solution systems.Methods: Adult rat spinal cord protein was precipitated with 10% trichloracetic acid in acetone and resuspended in 8 mol/L urea plus 4%CHAPS (A solution) or, 5 mol/L urea, 2 mol/L thiourea, 2%CHAPS plus 2%SB3-10 (B solution). One hundred and fifty micrograms of protein was loaded on 18 cm IPG strip holder and run isoelectric focusing electrophoresis as the first dimension, then horizontal SDS-PAGE as the second dimension. Protein spots were visualized by silver stain.Results:There were 1 059 and 1 023 protein spots in each map, of which 790 spots were matched in two maps. There were 269 and 233 spots exclusively extracted by A and B solutions, respectively. Taken together, 1292 different spots were totally obtained by A and B solutions.Conclusion: Integrating protein spots extracted by different solution systems is beneficial for achieving intact 2-DE map of tissues.

Objective:To purify HLA-DR molecules. Methods: Anti-HLA-DR antibody L243 was purified and coupled with CNBr activated Sepharose 4B gel. Immunoaffinity column was used to purify HLA-DR molecules. Results:Twenty micrograms of HLA-DR molecules were isolated from about 5 g Epstein-Barr virus-transformed human B lymphoblastoid cell line RAJI lysates by affinity chromatography. The purified HLA-DR molecules existed in α/β heterodimers form and could bind to conformation-dependent antibody L243. These HLA-DR molecules were separated into two strands,α and β,by boiling denaturation. These results are the basis for studying MHC Ⅱ binding peptide motif and CD4＋ T cell epitopes of antigens in future.

Objective: To study the recombinant epitope antigens of hepatitis C virus (HCV), in order to fulfil the requirements of recombinant immunoblot assay kit. Methods: An expressing vector pBVIL1 for expression of recombinant antigens in a fusion manner with IL-1β was constructed. A series of selected genes from the HCV antigens including the C, NS3, NS4 and NS5 were amplified from HCV gene-containing plasmids using PCR and the expression plasmids for these genes were constructed in pBVIL1, respectively. The activity of the purified recombinant antigens were tested against an identified HCV antibody positive and negative panel with ELISA. Results and Conclusions: All the cloned genes of chosen antigen epitopes were highly expressed in pBVIL1 in E.coli. The activity of the C and NS4 antigens were slightly higher than the RIBA3.0 antigens, while the activity of NS3 was slightly lower than the RIBA3.0 antigen. But the total evaluation for the panel was same as RIBA3.0. That means the cloned antigens were suitable for the use in RIBA test kit.