BACKGROUND:An efficient blood vessel system has a decisive effect on the survival and function expression of cells in three-dimensional tissues. Therefore it has been a hot research field in tissue engineering to find an appropriate vascularization strategy.
OBJECTIVE:To summarize and discuss the theory and research progress in vascularization strategies.
METHODS:Literature search was performed in PubMed database for English literatures published from 2003 to 2013. The key words are“tissue engineering, vascularization, endothelial cell, scaffold”in English. Then, the papers were further analyzed and reviewed in line with the theme.
RESULTS AND CONCLUSION:A total of 124 papers were searched. At last, 41 papers were selected according to the titles and objectives. Vascularization is the focus and pressing issue in tissue engineering field. There are many vascularization strategies, such as growth factor delivery, cellco-culture, dynamic-culture by bioreactor, scaffolds or decellularized scaffolds. But none of them is recognized as an effective strategy to achieve functional anastomosis with the host and sustain grafts survival for a long time in vivo. It wil be a big breakthrough in the future to co-culture pluripotent stem cells with other stem cells, combine with growth factors and optimize culture conditions for the differentiation in vivo.

Objective To investigate why benign, paroxysmal positional vertigo (BPPV) recurs.Methods Three hundred persons diagnosed with BPPV who had been treated at Tongji Hospital of Huazhong University of Science and Technology between April 2012 and April 2014 were given a telephone follow-up at least one year after their manual repositioning treatment.The respondents were divided into a healthy group and a recurrence group according to whether they said their vertigo had recurred.The age and gender distributions of the two groups were compared, along with their underlying diseases and living-related factors.Causes of the recurrence were then hypothesized.Results Single factor analysis and binary logistic regression analysis showed that overwork, an age over 45, travelling frequently, long use of computers, sleep disorders, oral intake of calcium tablets, posterior circulation ischemia and hyperlipidemia were all closely related to the BPPV recurrence.Age over 45 showed the strongest correlation.Conclusion Aging is the greatest risk factor for the recurrence of BPPV.Posterior circulation ischemia, hyperlipidemia, overwork, sleep disorders, long use of computers and being on business frequently are also predictors of relapse.

Objective To compare the results of the anterior approach (AA) with the conventional approach in the treatment of large hepatocellular carcinoma (HCC).Methods We searched the Medline,PubMed,Cochrane Library,Wanfang database on randomized clinical controlled trials and non-randomized clinical controlled trials comparing AA with the CA in right hepatic resection for large hepatocellular carcinoma.The data were analyzed with the RevMan5 software.Results Five non-randomized clinical controlled trials (NRCTs) and three randomized clinical controlled trials involving 615 patients (304 in the AA group,311 in the CA group) were enrolled into the analysis.There was no significant difference in the operation time between the two groups.Compared with the CA,the AA had lower intraoperative blood loss (WMD=-680.2 ml; 95％CI,-1023.97～-336.43;P=0.0001),blood transfusion rate (OR=0.38;95％ CI,0.25～0.59;P＜0.0001),intraoperative tumor rupture (OR=0.33;95％CI,0.11～0.97;P=0.04),surgical complication (OR=0.59;95％CI,0.38 ～ 0.93 ; P =0.02),hospital mortality (OR =0.37 ; 95 ％ CI,0.21 ～ 0.67 ; P =0.0009),and hospital stay (WMD=-4.75 d;95％CI,-7.82～-1.67;P=0.002).Conclusion AA is superior to CA in the treatment of larger.The operation time is the same for the 2 approaches.

The quality of a donor liver after cardiac death is closely associated with energy metabolism during preservation. Ex vivo mechanical perfusion has broad application prospects because this technique can help energy metabolism and repair ischemia injury of donors' livers. Some core issues are presented in this review in order to provide references for propelling secure application of liver transplantation based on donation after cardiac death.
Death ; Humans ; Liver ; Liver Transplantation ; Organ Preservation ; methods ; Perfusion ; methods ; Warm Ischemia ; adverse effects

Objective:To analyze the value of low dose enteral nutrition (EN) in treatment of septic shock combined with acute gastrointestinal injury Ⅲ (AGI Ⅲ).Methods:Clinical data of septic shock patients combined with AGI Ⅲ admitted at our hospital were analyzed.Patients were divided into two groups according to the nutrition therapy they received:treatment group (EN,n =41) and control group (no EN,n =46).The mortality and ICU hospital stays were collected.The intestinal barrier,inflammatory cytokines,and oxidative stress were evaluated before and after EN treatment.Results:For patients in the treatment group,the dosages of EN ranged from 200 to 410 kcal/d,with the median dose of 350 kcal/d.No significant differences were found on death rates between the two groups (24.4％vs 32.6％,P =0.398).Patients in the treatment group had shorter ICU hospital stays than those of the control group (11.8 ± 3.7 vs 16.2 ± 5.3,P ＜0.01).After one week EN treatment,patients in the treatment group had lower levels of CRP,IL-6,TNF-α,diamine oxidase,endotoxin and D-lactate than those of the control group (P ＜ 0.05).Conclusion:For septic shock patients combined with AGI Ⅲ,low dose EN can improve the intestinal barrier function and systemic inflammatory responses.

OBJECTIVETo develop a method for preparing a decellularized scaffold based on human liver tissue.

METHODSA surgical specimen of the left lateral lobe of the liver was obtained from a patients with hepatic hemangioma. The decellularization process was performed by repeated freezing-thawing, sequential perfusion with 0.01% SDS, 0.1% SDS and 1% Triton X-100 through the portal vein, and sterilization with peracetic acid. L-02 cells were then engrafted onto the decellularized liver scaffold.

RESULTSHE staining, DAPI staining and scanning electron microscopy all verified the absence of residual cellular components in the decellularized scaffold. The residual DNA content in the decellularized scaffolds was 25.3∓14.6 ng/mg (dry weight), which was less than 1% of the total DNA content in a fresh human liver. Immunohistochemistry demonstrated that type I and IV collagens, fibronectin and elastin were all retained in the scaffold. The engrafted L-02 cells survived well on the scaffold with active proliferation and expressed albumin and G6pc.

CONCLUSIONIt is feasible to prepare decellularized scaffolds using surgical specimens of human liver, which can be a new approach to constructing a tissue-engineered liver for clinical purposes.

Objective To develop a method for preparing a decellularized scaffold based on human liver tissue. Methods A surgical specimen of the left lateral lobe of the liver was obtained from a patients with hepatic hemangioma. The decellularization process was performed by repeated freezing-thawing, sequential perfusion with 0.01% SDS, 0.1% SDS and 1% Triton X-100 through the portal vein, and sterilization with peracetic acid. L-02 cells were then engrafted onto the decellularized liver scaffold. Results HE staining, DAPI staining and scanning electron microscopy all verified the absence of residual cellular components in the decellularized scaffold. The residual DNA content in the decellularized scaffolds was 25.3± 14.6 ng/mg (dry weight), which was less than 1% of the total DNA content in a fresh human liver. Immunohistochemistry demonstrated that type I and IV collagens, fibronectin and elastin were all retained in the scaffold. The engrafted L-02 cells survived well on the scaffold with active proliferation and expressed albumin and G6pc. Conclusion It is feasible to prepare decellularized scaffolds using surgical specimens of human liver, which can be a new approach to constructing a tissue-engineered liver for clinical purposes.

Objective To develop a method for preparing a decellularized scaffold based on human liver tissue. Methods A surgical specimen of the left lateral lobe of the liver was obtained from a patients with hepatic hemangioma. The decellularization process was performed by repeated freezing-thawing, sequential perfusion with 0.01% SDS, 0.1% SDS and 1% Triton X-100 through the portal vein, and sterilization with peracetic acid. L-02 cells were then engrafted onto the decellularized liver scaffold. Results HE staining, DAPI staining and scanning electron microscopy all verified the absence of residual cellular components in the decellularized scaffold. The residual DNA content in the decellularized scaffolds was 25.3± 14.6 ng/mg (dry weight), which was less than 1% of the total DNA content in a fresh human liver. Immunohistochemistry demonstrated that type I and IV collagens, fibronectin and elastin were all retained in the scaffold. The engrafted L-02 cells survived well on the scaffold with active proliferation and expressed albumin and G6pc. Conclusion It is feasible to prepare decellularized scaffolds using surgical specimens of human liver, which can be a new approach to constructing a tissue-engineered liver for clinical purposes.

OBJECTIVETo optimize the protocols for isolation, in vitro culture, identification and induction of hepatic differentiation of rat bone marrow mesenchymal stem cells (BMSCs).

METHODSRat BMSCs were separated and purified by differential adherent culture for 1.5 h with the first medium change at 12 h. The surface markers of BMSCs were detected by flow cytometry. The cells were induced to differentiate into adipogenic, osteogenic, and chondrogenesis lineages. A 3-step protocol including sequential addition of growth factors, cytokines and hormones was used to induce the BMSCs to differentiate into hepatocyte-like cells.

RESULTSThe cells isolated using this protocol were positive for CD29, CD44, and CD90 and negative for CD29 and CD45. The adipogenic, osteogenic, and chondrogenic differentiation of the BMSCs were verified by Oil red, Alizarin red, and toluidine blue staining. The BMSCs induced with the 3-step protocol differentiated into hepatic-like cells that expressed hepatocyte-specific proteins (ALB and AFP) and genes.

CONCLUSIONThe optimized protocol allows simple and efficient isolation of highly purified populations of BMSCs, which can be induced into hepatic lineages in specific microenvironment.

The aim of this study was to investigate the correlation between porcine epidemic diar-rhea virus(PEDV)S1 IgG antibody levels and neutralizing antibody potency in sow sera.Sera from 5 PEDV-infected farms with a clear immune background,5 non-infected farms and 5 infected farms with an unclear immune background,and sera from return-fed reserve pigs,totaling 716 copies,were collected and measured,and the correlation between PEDV S1 IgG antibodies and neutralizing antibodies was analyzed.The results showed that the PEDV S1 IgG and neutralizing antibodies of sow sera showed highly significant positive correlation,the correlation coefficient was 0.892(P＜0.000 1).Previous studies have shown that the level of PEDV neutralizing antibodies in sow serum correlates with the ability of piglets'maternal antibodies to resist PEDV infection.Therefore,the a-bility of maternal antibodies against PEDV in piglets can be evaluated by detecting PEDV S1 IgG antibodies in the serum of sows.In 10 PEDV-infected farms,the neutralizing antibodies to PEDV in the sera of sows after immunization were generally high,and the S1 IgG antibodies were also high,and their S/P values were higher than 3.5 in 66.9％of the farms(347/519),and the highest anti-body levels were found in the four farms in which PED did not occur,whereas the neutralizing an-tibodies in the immunized sows in the five PEDV-uninfected farms were generally low,and their S1 IgG antibodies were also low,and only 8.1％(13/161)having S/P values higher than 3.5.The re-sults suggest that most sows in PEDV-infected farms can provide good immunoprotection to pig-lets after immunization,while pigs in PEDV-uninfected farms need further immunization if they need to achieve a higher level of immunoprotection.The present study provides a substantial clini-cal basis for the use of PEDV S1 IgG antibody levels to assess the effectiveness of PEDV antibody protection in swine herds.