Liver diseases post great threats to human public health globally.Lacking of appropriate small animal models largely impeded the translational studies on human liver diseases, especially on viral hepatitis and related cirrhosis, hepatocellular carcinoma, etc.By human hepatocyte transplantation, the liver-humanized mice have significantly contribu-ted to the researches of human liver diseases.This review summarizes the currently widely used and representative human-ized mouse models, including uPA, FAH, TK-NOG, AFC8 mice and their applications in studies of human liver diseases.

Objective To establish an in vivo imaging method of normal or tumorous liver in mice by using a new type nanoparticle contrast agent, ExiTron nano 12000, coupled with micro-CT imaging.Methods Six 6-8-week old male C57BL/6J mice were randomly divided into group A and group group B, by intravenous injection of 50μL and 100μL Ex-iTron nano 12000, respectively.In vivo Micro-CT scans were performed before contrast agent injection, 3 minutes, 24 hours, 7, 14, 28 and 56 days after injection.To determine which dose is suitable for long-term studies, gray scale value a-nalysis was performed on selected region of interest ( ROI) in the left lobe and right anterior lobe of the liver, and the chan-ges of liver tissue contrast was monitored after ExiTron nano 12000 injection.Three male HBV transgenic mice bearing liver tumors ( group C) were intravenously injected with the determined dose of ExiTron nano 12000 and were monitored by mi-cro-CT scans as above described.At 56 days after ExiTron nano 12000 injection, the mice were sacrificed and liver sam-ples were taken for histological analysis.Results Cross-sectional images taken at various time points and the average gray scale value ( AGSV) analysis in the mouse liver revealed that the AGSV peaked at 24 hours after injection of contrast rea-gent and good contrast still presented in the livers within 56 days of observation for both groups, though group B showed a significantly higher contrast than group A (P＜0.01).Those data indicated that the dose of group B (100μL) was better to maintain ExiTron nano 12000 in the liver of mice for a long time.Contrast-enhanced by 100μL of ExiTron nano 12000, the liver tumor nodules in the mice of group C could be clearly delineated by Micro CT imaging during a 56 days observa-tion.Histological analysis revealed atypical hyperplasia, enlarged nuclei with hyperchromasia and cell necrosis in the tumors.Conclusions An in vivo imaging method was established to non-invasively visualize mouse liver using micro-CT combined with nanoparticle-based contrast agent and this technology may be applied to a live imaging of murine primary liv-er tumors.

Objective: To observe the histological changes of lamina extema cranii at both the graft and donor areas after having been grafted in animal experiment. Methods; 4 mini pigs aged from 8 to 12 months were selected. Part of the outer table of skull (2.5 cm × 1.0 cm) was decorticated and was divided equally. Both were implanted on each side of the snouts of animals. 2 pigs were selected randomly and were killed 12 weeks postoperation. Each 1, 0 cm ×0. 5 cm specimen was harvested and histological study was performed. The other 2 animals were killed 24 weeks after operation. Gross inspection of the donor site was performed and histological study was done. Results; In the graft area; bone absorption was obvious 12 weeks postoperation, but bone matrix increased obviously at 24 weeks postoperation. Results of scanning electron microscope showed that interface between bone graft and recipient site was discernment and collagen type I was malaligned 12 weeks postoperation. Collagen fibers were in good order and good mineralization was found 24 weeks postoperation. In the donor area; small amounts of new bone formation could be seen and alignment of cemental line was chaotic 12 weeks postoperation. At 24 weeks, bone formation was obvious and alignment of haversian canal was regular. Scanning electron microscopy showed that structure of the tissue was uneven and disorder at 12 weeks postoperation. Collagen fibers were in good order and good mineralization was found 24 weeks postoperation. On gross view, raw surface of the donor site got complete healing, os-teanagenesis was incomplete and introcession could be observed in the local area. Conclusion; Histological remodeling of lamina exter-na cranii is complete at 24 weeks after having been grafted. The donor site can regenerate but morphologic introcession could be observed.

Objective:To investigate the effects of 5-aza-2′deoxycytidine(5-aza-dC),a DNA methyltransferase (DNMT)inhibitor, on the methylation status of the RECK gene and the invasion of salivary adenoid cystic carcinoma cell lines.Methods:Methylation-specific PCR,Western blot analysis and quantitative real-time PCR were used to investigate the methylation status of RECK gene and the expression of RECK mRNA and protein in SACC cell lines.The invasive ability of SACC cells was examined by transwell assay. Results:Promoter methylation was only found in ACC-Mcell line and not in ACC-2 cell line.Treatment of ACC-Mcells with 5-aza-dC partially reversed the hypermethylation status of the RECK gene and significantly enhanced the expression level of mRNA and pro-tein of RECK,suppressed ACC-Mcell invasive ability.Conclusion:5-aza-dC can inhibit ACC-Mcell invasion by reversal of hyperm-ethylation status of RECK gene.

Objective:To investigate the clinical characters and treatments of maxillofacial fractures. Method: A review of 101 maxillofacial fractures was presented with respect to age, sex, cause of fractures, pattern of fractures, treatments and therapeutic effect. Result:The majority of fractures were found in 20-to-50-years-old males. Most fractures happened in summer and the leading causes were traffic accidents. Mandible was the most part of fractures and associated combined injures were found in 31 cases. Rigid internal fixation was the primary treatment. Conclusion:Maxillofacial factures mainly occurred in young adult males and traffic accidents were the main causes. Rigid internal fixation after exact replacement was the primary common treatment.

Objective To establish uPA inducible expression system using recombinant retroviral system for the further construction of inducible uPA-SCID animal model .Methods The Inducible expression system need to construct two plasmids:pLNHXO1O2-Alb-GLUC-FMN2A -rtTA and pLNHXO5O6-TRE2-uPA-IRES-ZsGreen respectively. Both plasmids were based on retroviral vector pLNHX , Albumin promoter gene ( Alb) and rtTA gene or uPA gene and ZsGreen were obtained by PCR reaction and inserted into pLNHX .The Gaussia enzyme fluorescent element ( GLUC) was used to monitor rtTA expression in pLNHXO1O2-Alb-GLUC-FMN2A-rtTA, and the ZsGreen for uPA expression monitoring in pLNHXO5O6-TRE2-uPA-IRES-ZsGreen.The correct constructed plasmids were transfected into packaging cell line GP 2-293 to gain recombinant viral particles .NIH/3T3 cells were infected with these viral particles and selected with G 418.Gene expression in the surviving cells was confirmed by the PCR method .Results The recombinant retroviral vectors harbouring target genes were successfully cloned .The rtTA gene in pLNHXO1O2-Alb-GLUC-FMN2A-rtTA was expressed, and uPA can be induced to express in pLNHXO5O6-TRE2-uPA-IRES-ZsGreen by doxycycline (Dox) when the plasmid transfected into the HepG-Tet-on cell.The constructed recombinant two retroviral vectors were transfected into GP 2-293 packaging cells respectively to gain infectious viral particles .Then,NIH/3T3 cells were infected with these viral particles and single-cell clones which stably expressed the transgenes were successfully established .Conclusion This study primarily established uPA inducible expression system , it laid a foundation for the murine model of inducible liver damage , and provided a novel technical platform for further building the liver humanised murine models for viral hepatitis studying .

Objective To investigate the effect of neonatal overfeeding on the expression of lipid metabolic associated enzymes and molecular mechanisms in the livers of rats. Methods Male Sprague-Dawley rats were randomly assigned to litter sizes of three group ( small litters,SL group) or ten ( normal litters,NL group) on postnatal day 3. Body weight,milk intake,liver and fat pad (epididymal and retroperitonea) weight,and hepatic histological anal-ysis were recorded in week 2 and week 3,respectively. The levels of lipids were detected by the automatic biochemical analyzer. The mRNA expressions of acetyl-CoA carboxylase ( ACC) ,lipoprotein lipase ( LPL) ,liver-type fatty acid-binding protein (L-FABP), carnitine palmitoyltransferase 1(CPT1),microsomal triglyceride transfer protein (MTP), sterol regulatory element-binding protein-1c (SREBP-1c) and peroxisome proliferator activated receptorα(PPARα) in liver were determined by real time PCR;the protein expressions of SREBP-1c and PPARα were determined by Western lot. Results As early as week 2,the body weight of rats in SL group began to elevate (t=-5. 997,P<0. 001) and food intake (t=-3. 462,P=0. 002) compared with the rats in NL group,and persistent to weaning (body weight:t=-17. 019,P<0. 001;food intake:t=-2. 276,P=0. 031). By the time of 3 weeks old,SL rats increased visceral fat pad [ret-roperitonea (t=-7. 643,P<0. 001),epididymal (t=5. 997,P=0. 001)],liver weight (t=-7. 812,P<0. 001),hepatosomatic index (t=-3.829,P=0. 003) and serum triglyceride (TG) level (t=-2. 703,P=0. 022) compared with those of NL rats,as well as the level of hepatic ACC mRNA (t=-3. 751,P=0. 007),LPL (t=-2. 721,P=0. 017) and L-FABP mRNA (t=-2. 521,P=0. 026) . While CPT1 mRNA (t=-1. 531,P=0. 155) and MTP mRNA (t=-1. 741,P=0. 098) levels remained unchanged in both groups. Hepatic SREBP-1c mRNA expression increased in SL rats after 2 to 3 weeks (t=-2. 836,P=0. 016),paralleled with ACC and LPL mRNA expression;while the mRNA and protein expression of PPARα re-mained unchanged (t=-0. 854,P=0. 411). Conclusions Postnatal overfeeding can promote higher liver pad and dyslip-idemia at the time of weaning. The process may be regulated by up-regulated expression of ACC, LPL and L-FABP. SREBP-1c may be participated in the regulation of ACC,a rate-limiting enzyme involved in lipogenesis.

Objective:To investigate the effect and mechanism of Wogonin on CD3AK cell proliferation and cytotoxicity to SMMC-7721.Methods:CD3AK cells were cultured from peripheral blood mononuclear cells ( PBMC) in vitro by a variety of cytokines for 7 d,and treated with different concentrations of Wogonin for 48 h.CD3AK cells proliferation was measured by CCK-8 assay.SMMC-7721 cell growth was detected by MTT.The expression of perforin (PFP),granzyme B (GrB) and CD107a on CD3AK cells were measured by flow cytometry ( FCM).The cytotoxicity to SMMC-7721 cells was detected by LDH release assay.The expression of ERK1/2 on CD3AK cells was detected by Western blot.The mobility of SMMC-7721 cells was detected with transwell chambers.The merge of SMMC-7721 cells were measured with Wound healing assay.Results:Wogonin could significantly promote CD3AK cells proliferation, especially at 3.2 mg/L (23%higher than that of control group,P<0.05).The highest cytotoxicity to SMMC-7721 was also at the con-centration 3.2 mg/L (60.4%).The expression of PFP,GrB,CD107a were significantly higher than that of control group( P<0.05).The expression of ERK1/2 was obviously improved,especially at 12.5-0.8mg/L.After treated with Wogonin 50,12.5,3.2,0.8,0.2 mg/L for 48 h,the lowest transwell cell was at 12.5 mg/L and lowest merge rate was at 3.2 mg/L.Conclusion:Wogonin could promote CD3AK cell proliferation and enhance the cytotoxicity to SMMC-7721.Wogonin could also inhibit SMMC-7721 cell growth,migration and cell merge.The mechanism may be related to activated ERK1/2 and increase the expression of PFP,GrB,CD107a.

The treatment results of radiofrequency ablation (m) were analyzed in l5 patients with the complicated Supraventricular tachycardia(SVT)． The causes of SVT were dual accessory pathway(AP) in 9 patients, single M with slow-fast atrioventricular junctional reentrant tachycardio (AVJRT) in 5 patients and single AP with slow fast/fast-slow AVJRT in l patient． Results: 24 APs and 6 slow pathways of atrioventricular node were abl a ted． All patients were successful． During the follow-up of 6～48 months, there were no recurrence in l5 patients, also there were no occurrence of atrioventricular block and other complications． Conclusion: Using the proper methods of m of the complicated SVT would have a h igher successful rate, a lower recurrent rate and lower complications．

AIM: To investigate whether RNA interference (RNAi) induced by small interference RNA (siRNA) could suppress Polo- like kinase- 1 (Plk 1 ) expression and its effects in A549 cells. METHODS: A recombinant plasmid containing siRNA targeting Plk1 ( psiRNA - hH1 - Plk1 ) was transfected into A549 cells with Lipofectamine 2000.Expressions of Plk1, cyclin B1 and p53 protein were detected by Western blotting. Cell proliferation was evaluated by direct cell counting, while cell cycle and apoptosis were examined by flow cytometry, and expression of α - tubulin was detected by immunofluorescence. RESULTS: The results demonstrated that sequence specific siRNA targeting Plk1 was capable of suppressing Plk1 expression, and reflecting in lower kinase activity in A549 cells. The level of Plk1 protein was reduced by at least 70％ after 48 h of psiRNA - hH1 - Plk1 treatment relative to controls. Expressions of cyclin B1 and p53 were increased greatly after Plk1 depletion, and cells showed absence of microtubule polymerization and spindle abnormalities in staining for α -tubulin. Growth inhibition, G2/M arrest and apoptosis were observed in psiRNA -hH1 -Plk1 transfected group. CONCLUSION: All these data suggest that siRNA targeted against human Plk1 may be a valuable tool in cancer therapy.