1.Design and development of artificial substitute for bile duct
Kai LIU ; Songyang LIU ; Guangyi WANG
Chinese Journal of Tissue Engineering Research 2008;12(18):3592-3596
BACKGROUND:The operation of bile duet has always been the most difficult part in the general surgery.The Patients have a high morbidity of the post-operative complications,such as bile duct stenosis,repeated biliary tract infection,and even biliary hepatocirrhosis.Therefore.we are seeking for some kind of artificial bile dlIct to take the place of the damaged one.and then solve the problem in bile duct's repair and reconstruction.OBJECTIVE:This paper reviewed the Iong-term plenty of related studies and litcratures.and then summarized the latest progress of the design and improvement of artificial bile duct.So we could design the optimum artificial bile duct.RETIUEVAL STRATEGY:A computer-based online search of PubMed database (http://www.pubmed.gov/)was undertaken to identify articles about artificial bile duct published in English from January 1959 to December 2007 with keyword of"artificial bile duct,stem cell,tissue engineering".Meanwhile,Chinese articles about artificial bile duct published from January 1994 to October 2007 were retrieved in China National Knowledge Infrastructure(CNKI,http://www.cnki.net),the keyword was"artificial bile duct,stem cell,tissue engineering"in Chinese.Inclusion criteria:①laboratorial and clinical researches about artificial bile duct;② clinical researches about the stem cells;③researches about tissue engineering and biocompatible materials.Exclusion criteria:repeated study.Initial reading these literatures and finding the full text,37feferences were included from the gleaning 414 literatures.LITERATURE EVALUATION:A total of 37 articles were involved.ineluding 10 about background.5 about autotransplant,5 about stem cell technique,2 about nanotechnology,1 about structure of mechanical bile duct,2 about macromolecular materials.and 12 about the latest progress.DATA SYNTHESIS:To analyze and sort out these literatures.the artificial bile duct from biocompatible materials and biomedical engineering is analyzed.The developments in autotransplantation,mechanical structure,nanotechnology,stem cell technique and tissue-engineered macromolecule material have been retained.So far,the tissue-engineered macromolecule material is the best one.Further study aiming at the better artificial bile duct is needed.CONCLUSION:There have been great progresses in research of artificial bile duct,however,there is no significant achievement because of the inextricable shortcomings and limits in autotransplantation,mechanical structure,nanotechnology and stem cell teehnique.Therefore.the tissue-engineered macromolecule material has become the best material for artificial bile duct.
2.Feasibility of fluoroelastomer-246B as the substitute of bile duct
Kai LIU ; Guangyi WANG ; Songyang LIU
Chinese Journal of Tissue Engineering Research 2008;12(10):1977-1982
BACKGROUND: Fluoroelastomer-246B has better histocompatibility than polyethylene and polypropylene, which is the same as expanded polytetrafiuoroethylene (ePTFE). Besides, fluoroelastomer-246B has better rigidity than ePTFE, so it is hard to deform.OBJECTIVE: To investigate the feasibility of fluoroelastomer-246B as a human implant in vivo and a substitute of human bile duct by the test of bile soak, routine sterilized method, and implantation into rat abdominal cavity.DESIGN: A controlled observation.SETTING: First Hospital of Jilin University & Key Laboratory of Education Ministry for Supramolecular Structure and Material of Jilin University.MATERIALS: This study was performed at the Key Laboratory of Education Ministry for Supramolecular Structure and Material of Jilin University from June 2006 to March 2007. A total of 35 male Wistar rats of clean grade, aged 4-5 weeks,weighing 140-160 g, were provided by Laboratory Animal Center, School of Basic Medical Sciences, Jilin University [Permission No. SCXK (Ji) 2003-0001]. Prior to surgery, the Wistar rats were fasted for 5 hours, but they were allowed to access to water freely. The main materials used in the present study were as follows: fluoroelastomer-246B (Yangzhong Municipal Rubber & Plastics Plant, China), ePTFE(Shanghai Suo-Kang Medical Implants Co.,Ltd., China).METHODS: Rectangular fluoroelastomer-246B thin slices (50 mm×10 mm×0.5 mm) made were placed in a beaker filled with fresh bile, and preserved in a 37 ℃ thermostat container. The tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B were tested after 30 days, and the results were compared to those before soaking to investigate whether the physical-chemical properties of fluoroelastomer-246B slices would change after soaking in the bile environment for a long time. The rectangular fluoroelastomer-246B thin slices made as above were sterilized by boiling method, formaldehyde vapors fumigating method, and formaldehyde fluid soaking method. The indices mentioned above were measured, and the data were compared to those before sterilizing to identify whether fluoroelastomer-246B could be used after sterilizing. The same-size slice of fluoroelastomer-246B,ePTFE, polypropylene and polyethylene was separately implanted into rat abdominal cavity. The slices were taken out after 30 days, and the pathological sections of surrounding tissues were made to observe whether allergic response and/or inflammatory reactions existed.MAIN OUTCOME MEASURES: After fluoroelastomer-246B thin slices were soaked in bile for 30 days, their tensile strength, thermal decomposition temperature and glass transition temperature were tested, and the results were compared to those before soaking. After fluoroelastomer-246B thin slices were sterilized by boiling method, formaldehyde vapors fumigating method, and formaldehyde fluid soaking method, the indices mentioned above were measured, and the data were compared to those before sterilizing. The numbers of cells with allergic response and cells with inflammatory reaction were counted.RESULTS: After soaking in the fresh bile for 30 days, the tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B changed slightly compared to before soaking (P>0.05).Fluoroelastomer-246B could well antagonize mechanical stress after bile soaking and sterilizing. Under going sterilizing by boiling method, formaldehyde vapors fumigating method and formaldehyde fluid soaking method separately, the tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B had no marked changes (P>0.05). No noticeable allergic response was observed after fluoroelastomer-246B was implanted into rat abdominal cavity, whereas slight inflammatory reaction was detected, which was similar to ePTFE (P>0.05).CONCLUSION: The primary physical-chemical properties of fluoroelastomer-246B do not change after soaking in bile for 30 days. Fluoroelastomer-246B can well antagonize mechanical stress and be used after sterilizing without metaphysis or allergic response. Therefore, fluoroelastomer-246B can be used as a substitute of bile duct.
3.Implantation of bone marrow mesenchymal stem cells inhibits Bcl-2 and Bax-mediated neuronal apoptosis in rats after cerebral ischemic injury
Guangyi LIU ; Shuhua ZHOU ; Shuxian XU
Chinese Journal of Tissue Engineering Research 2007;11(50):10205-10208
BACKGROUND: The implantation technique of bone marrow mesenchymal stem cells (MSCs) is of important significance for repair of brain injury. However, its action pathway still needs to be investigated.OBJECTIVE: To observe the changes of Bcl-2 and Bax expressions in the injured regions of cerebral cortex and hippocampus of rats with cerebral ischemia in which MSCs were implanted, and to analyze the action mechanism of intracranial implantation of MSCs inhibiting neuronal apoptosis.DESIGN: A randomized controlled experiment.SETTING: Institute for Cerebrovascular Disease, the Affiliated Hospital of Qingdao University Medical College.MATERIALS: Twenty-four male adult Wistar rats, weighing 180 to 240 g, were provided by the Experimental Animal Center of Shandong University. The involved rats were randomized into 3 groups with 8 in each: control group, injury group and implantation group. 5-bromodeoxyuridine (BrdU, Sigma Company), TUNEL kit, Bcl-2, Bax antibody kit were purchased from Beijing Zhongshan Bioengineering Company.METHODS: This study was carried out in the Institute for Cerebrovascular Disease, the Affiliated Hospital of Qingdao University Medical College between April 2005 and September 2006. Rats in the injury group and implantation group were developed into rat models of cerebral ischemia by suture of external carotid artery. Seven days later, the successful rat models in the implantation group were injected in the cerebral cortex and striatum with 2×1012 L-1 MSCs suspension primarily cultured in vitro. The processing of the experimental animals corresponded to the requests of Animal Ethics.MAIN OUTCOME MEASURES: Neuronal apoptosis and Bcl-2 and Bax expressions in the injured regions of cerebral cortex and hippocampus were detected by TUNEL staining and immunohistochemical method on the 7 and 14 days after successful modeling, separately.RESULTS: ①Neuronal apoptosis: On the 7th day after successful modeling, apoptotic cells were not found in the control group, and apoptotic cells in the implantation group were significantly fewer than those in the injury group (P <0.01). ② Bcl-2 and Bax expressions: On the 14th day after successful modeling, Bcl-2-positive neuronal expression in the cerebral cortex and hippocampus of rats in the injury group was significantly weaker than that in the control group and implantation group (P < 0.01). Bax-positive expression in the cerebral cortex and hippocampus of rats in the injury group was significantly stronger than that in the control group and implantation group (P < 0.01).CONCLUSION: MSCs can promote Bcl-2 expression and inhibit Bax expression of rats with cerebral ischemia injury,and accordingly neuronal apoptosis will be reduced.
4.Effects of glutamine-enriched early enteral nutrition on intestinal mucosal barrier injury after liver transplantation in rats
Guangyi LIU ; Yang LI ; Haitao GU
Chinese Journal of Organ Transplantation 2013;(5):304-308
Objective To observe the effect of glutamine-enriched early enteral nutrition on intestinal mucosal barrier injury after orthotopic liver transplantation in rats.Method Male Wistar rats,the recipients were randomly divided into three groups:control group (control group,n =10),orthotopic liver transplantation group (OLT group,n =30) and glutamine-enriched early enteral nutrition group (EEN group,n =30).Only dissecting hepatoduodenal ligament was performed in control group,and OLT was performed from Wistar to Wistar rats by modified two-cuff method in OLT group and EEN group.For EEN group,recipients were supplied with Nutrison Fiber (125 ml/kg every day) plus Gln (0.3 g/kg every day) for 3 days before and 3 h after surgery by gastric perfusion.For OLT group,the same volume of normal saline was administered instead of the Nutrison in the same time.No special treatment was given in control group.The levels of plasma endotoxin,D-lactic acid,and TNF-α were determined at different time points in the three groups.The ultrastructural changes of ileal mucosa were observed under the transmission electron microscopy.At the same time,the remaining 5 rats per group were used for observing the lifetime.Result As compared with control group at 12,24 and 72 h,the levels of plasma endotoxin,D-lactic acid,and TNF-α were significantly increased in OLT group and EEN group (P<0.01),and as compared with OLT group,the above-mentioned indexes were obviously decreased in EEN group at 24 and 72 h (P< 0.01).The ileal mucosal epithelial clearance in control was normal,and microvilli arranged neatly under the electron microscope.the ultrastructure damage in OLT group was more serious than in EEN group at 12,24,and 72 h.As compared with control group at 12,24,and 72 h,the expression levels of TNF-α mRNA were significantly increased in OLT group and EEN group (P<0.01),and as compared with OLT group,the expression levels of TNF-α mRNA were obviously decreased in EEN group (P<0.01).The survival time in cntrol group was significantly longer than in OLT group and EEN group (P<0.05),and as compared with OLT group,the survival time in EEN group was obviously extended (P<0.05).Conclusion OLT can lead to the damage of intestinal mucosal barrier,and glutamine-enriched early enteral nutrition is a potent protection against intestinal mucosal barrier injury and prolongs the survival time of rats after OLT.
5.Investigation of the relationship between IL-6 levels and neuronal damage after cerebral ischemic reperfusion in rats
Jianbo XIE ; Jianzhang JIANG ; Guangyi LIU
Journal of Clinical Neurology 1995;0(04):-
0.05).The expression began to increase around the infarction at 12h reperfusion,it reached the peak at the 3th day in the boundary zone and then it gradually decreased.Conclusion The overexpression of IL 6 played an important role in the course of cerebral ischemic reperfusion, and could damage the brain tissue.
6.The apoptosis of endothelial cell and the relation between it and the expression of P53 after focal cerebral ischemia reperfusion in rats
Haowen XU ; Guangyi LIU ; Yunliang GUO
Journal of Clinical Neurology 2001;0(05):-
Objective To study the apoptosis of endothelial cells and the relation between it and the expression of P53 protein after focal cerebral ischemia reperfusion in rats.Methods The apoptosis of endothelial cell 2,6,12 h and 1,2,3,7,14,21 d after cerebral ischemic reperfusion were observed using an in situ end labeling method,and the expression of P53 protein was detected by immunohistochemical staining methods.Results Apoptotic endothelial cells in ischemic penumbra were observed 2h after cerebral ischemic reperfusion, they peaked at 12~24 h, and decreased gradually.There was no remarkable difference between it and the sham operative group at 21 d.The P53 protein began to express 6h after cerebral ischemic reperfusion, it peaked at 1~2 d, and then declined gradually to controlled level at 7d. The expression peak time of P53 was 24 h later than that of cell apoptosis.Conclusion Apoptosis was a pattern of endothelial cell death after reperfusion of MCAO. P53 protein played an important role in the process of apoptosis of endothelial cells.
7.Influence of Laparoscopic Surgery on the Expression of Potential Metastasis-related Molecules and Implantation of Endometrial Cancer
Chun FU ; Guangyi LI ; Fengying LIU
Chinese Journal of Minimally Invasive Surgery 2001;0(02):-
0.05).Follow-up was available for(14.2?3.6) months(range,7-19 months) in the laparoscopic group and for(13.1?4.2) months(range,7-19 months) in the laparotomy group.No recurrence was detected in both the groups during the follow-up.ConclusionLaparoscopic surgery do not affect the expression levels of the factors,including E-cadherin,MMP-2,VEGF-C,and CD44v6,that influence the metastasis and implantation of tumor cells in patients with endometrial cancer.
8.Treatment of hyperlipidemic pancreatitis
Xiaoju SHI ; Guangyi WANG ; Yahui LIU ; Yingchao WANG ; Kai LIU
Chinese Journal of Hepatobiliary Surgery 2011;17(11):949-952
Recently,there is a gradual increase in the incidence of hyperlipidemic pancreatitis with high serum triglyceride (TG) levels.The treatments include general measures,lipid-lowering drugs,blood purification,low molecular weight heparin and insulin,traditional medicine,improving microcirculation,surgical therapy and gene therapy.The prevention of recurrence of hyperlipidemic pancreatitis is different from other types of pancreatitis.
9.Biological effect of artificial bile duct combined with bionic valve made by fluoroelastomers-246B following implantation in dogs
Kai LIU ; Guangyi WANG ; Songyang LIU ; Junfeng YE
Chinese Journal of Tissue Engineering Research 2007;0(21):-
0.05). At day 30 after operation,half-pipe blockage occurred,and some yellow-green sediments were observed on the pipe wall in the straight tube group; a few of yellow-green sediments were found at top of wall,and some white floc sediments were observed in lumen but nothing was observed on valve in the venous valve tube group; a few of yellow-green sediments were found on pipe wall near the living valve,and some white floc sediments were observed in bile in the living valve tube group. At day 30 after operation,epithelium of mucous membrane was not intact,and gland proliferated lightly in the straight tube group; epithelium of mucous membrane was generally intact,and proliferation of gland was not found in the venous valve tube group; epithelium of mucous membrane was exactly intact,and glandular epithelial cells were not heteromorphism in the living valve tube group. CONCLUSION:The artificial bile ducts with a valve structure and living value structure has a good patency and plays an effective role of anti-reflux after a short-term observation,suggesting that a valve structure acts as a similar function to Oddis sphincter.
10.The comparative study of perfusion MR imaging in primary central nervous system lymphomas and high grade astrocytomas
Biao HUANG ; Changhong LIANG ; Hongjun LIU ; Guangyi WANG ; Zhenggen ZHOU
Chinese Journal of Radiology 2008;(3):276-280
Objective To investigate the value of perfusion MR imaging in differential diagnosis between primary central nervous system lymphomas(PCNSL)and high grade astrocytomas.Methods Twelve patients with PCNSL and 23 patients with high grade astrocytomas were preoperatively examined using a 1.5T MR unit.Routine MR sequences were performed followed by dynamic susceptibility contrastenhanced MR perfusion imaging.The perfusion color images and the time-signal intensity curves of the two tumor groups were compared.The relative cerebral blood volume(rCBV)within the tumor parenchyma was measured and the data were analyzed with unpaired Student's t-test.Results The rCBVs within the tumor parenchyma of the PCNSL and high grade astrocytomas were 1.78±0.5 1 and 3.87±0.87 respectively.The rCBV in the PCNSL was significantly lower than that of the high grade astrocytoma(P<0.05).When the time-signal intensity curves were compared,the PCNSL showed a trend towards the baseline after the first pass and the curves even overshot above the baseline in 7 out of 12 cases,whereas the high grade astrocytoma showed a trend to be close to the baseline but couldn't return to the baseline completely.Conclusion The MR perfusion imaging can be very useful in distinguishing the PCNSL from high grade astrocytomas.