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A microcapsule is a spherical, with a diameter that can be controlled in the range of 200 -1500 μm and biocompatible semipermeable membrane, which allows the bidirectional diffusion of nutrients,oxygen, secreted therapeutic product, and waste but prevents the penetration of high molecular weight substances from the microcapsule, such as antibodies and immunocytes. In comparison to monolayer culture and multicellular tumor spheroid model, orthotopic injection of microencapsulated tumor cells has uncomparable advantages in cell proliferation, mimicking the in vivo situation, making orthotopic tumor model and distant organ metastases model. Microencapsulated tumor assay has the potential of being widely used for in vitro anticancer drug screening and evaluation of the effects. This article mainly reviews the advantages of microencapsulated tumor assay and its application.
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Pancreatic cancer is a highly malignant tumor. Animal models of pancreatic cancer included xenograft models, carcinogen induced models, genetically engineered models. Xenograft models are relatively reliable and feasible, but the growth pattern is different between serve immunodeficienct animals and human beings. Carcinogens induced models simulated the environmental factors to reconstruct the development of pancreatic cancer. But carcinogens could have other biological effects. Genetically engineered models could make the occurrence of pancreatic cancer at the molecular level. But it is difficult to control the transgenic product accurately. No model could meet all the needs of different experiments. It is important to choose a suitable animal model in different experiments.
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Objective To observe the process of polyamidoamine dendrimer modified single walled carbon nanotubes complexes (CNT-PAMAM-D) entering into pancreatic cancer BxPC3 cells, and to evaluate its safety as a vector. Methods The CNT-PAMAM-D were prepared by ultrasound, mixing and rinsing, and the morphology was characterized by atom force microscopy and transmission electron microscope. Then the prepared CNT-PAMAM-D was incubated with human pancreatic cancer cell line BxPC3 cells for 12, 48, 72hours, and then the cells were collected. Distribution of CNT-PAMAM-D in cells and cell ultrastructure was observed by transmission electron microscopy. Results After the combination of PAMAM-D and CNT, the surface of CNT was surrounded by dendrimer and nanocomposite particles with a size of 20 nm was formed. It was showed that CNT-PAMAM-D could be transfected into human pancreatic cancer cells by cell pinocytotic way, and it entered cytoplasm at 12 h. With the extension of the transfecting time, CNT-PAMAM-D could enter lysosomal and nucleus, but the morphology and ultrastructure ocf BxPC 3 cells was not significantly changed. Conclusions The CNT-PAMAM-D is a highly effective and safe nano vector.
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The solid pseudopapillary tumor of pancreas (SPT) is a rare pancreatic tumor with low malignant potential. It primarily affects young women. The clinical characteristic is nonspecific, but the pathological characteristic is distinct. The tumor consists of both cystic and solid component. The typical histopathological appearance of SPT is the pseudopapillary structure with a fibrovascular surrounded by several layers of epithelial cells.Only a few SPTs present invasive behaviors. The tumor cells express a wide range of immunohistochemical markers. The pathogenesis is associated with the Wnt signaling pathway, which is changed by β-catenin, Pl20-catenin, adenomatous polyposis coli gene( APC), the cyclin-dependent kinase inhibitors p21 and p27.
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Objective To summarize and analyze the pathological characteristics of solid pseudopapillary tumor of pancreas (SPTs).Methods The clinical data of 51 cases of SPTs were retrospectively analyzed.The immunohistochemical localizations of different markers (HSE,SYN,CD_(56),CD_(10),Nestin,Vim,a1-ACT,EMA,AE1/AE3 and CK19) on 39 SPTs were studied.Results Pathological features included a combination of solid and cystic components with pseudopapillae formation and degenerative regions without glands.Among the 39 cases of SPTs,the expression rate of NSE was 97.4%,the expression rate of CD_(56),CD_(10) was 84.6%,the expression rate of Nestin and Vim was 64% and 87%,the expression rate of S100 was 79.5%,the expression rate of a1-ACT and a1-AT was 82.1% and 79.5%,while the expression rate of SYN was 12.8%;however there was low expression and weak positive reaction of EMA,AE1/AE3 and CK19.Conclusions The typical pathological characteristics of SPTs may result from gradual degenerative changes induced anoxemia in some SPT's areas.The heterogeneity of SPTs on different antibody markers showed that the SPTs may be originated from pancreatic embryonic stem cells,and result from immature differentiation of the pluripotential stem cells during pancreatic genesis.
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Objective To evaluate reoperations for benign bile duct strictures after a prewousRoux-en-Y hepaticojejunostomy.Methods Clinical date of 28 patients with previous reconstruction of Roux-en-Y hepaticojejunostomy for benign bile duct strictures were retrospectively analyzed.For data staftstical analysis t-test and stepwise logistic regression analysis were used.Results Reoperative surgery was performed for residual biliary stones with bile duct stricture in 10 cases(35.7%),simple anastomotic stricture of hepaticojejunostomy in 11 cases(39.3%),remained biliary stricture after initial rear in 6 cases (21.4%).anastomotic leakage with duodenal leakage in one case(3.6%).Mode of reoperation:18 cases (64.3%)underwent hepatic lobectomy with Roux-en-Y hepaticojejunostomy,liver splitting approach to Roux-en-Y hepaticojejunostomy in 5 cases(17.9%),right hemihepatectomy in one case(3.6%),resection of anastomotic stenosis involved segment and Roux-en-Y hepaticojejunostomy in one case(3.6%),abdominal drainage and duodenum fistulization and jejunum ostomy in one case(3.6%),choledocholithotomy with T-tube drainage in 2 cases(7.1%);Thirteen patients(46.4%)developed postoperative complications.Conclusion Biliary tract stenosis remains the main cause for reoperation in patients undergoing a faeled reconstruction.Wide and patent biliary tract drainage and reconstruction somenmes necessitate a hepatic lobectomy.
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OBJECTIVE:To create an in vitro harvesting method of culturing a large number of adult bone marrow MSCs(BMSCs) DESIGN,TIME AND SETTlNG:The randomized, controlled study was performed at the Shanghai Institute of Digestive Surgery (Key Laboratory of Education Committee of Shanghai City),as well as Department of General Surgery and Organ Transplantation Center,Ruijin Hospital,Medical College.Shanghai Jiao Tong University from September 2005 to April 2006.MATERIALS:Bone marrow samples were collected from normal persons.who did bone marrow examination at the Department of Hematology,Ruijin Hospital,Medical College.Shanghai Jiao Tong University.Donors were volunteers who signed the informed consent.METHODS:Human BMSCs were harvested using Pemoll gradient centrifugation and adherence method.and then incubated in microcarrier cytodex3.Common monolayer polystyrene was incubated as controls.Cell phenotype and proliferative activity were tested utilizing flow cytometry and MTT.MAIN OUTCOME MEASURES:Collection.incubation,morphology of human BMSCs.and prolireration and cell cycle of human BMSCs on the cytodex 3 were measured.RESULlTS:Flow cytometry detection showed that the surface marker of human BMSCs on the cytodex3 was ldentical to that on the common monolayer polystyrene;BMSCs were positive for CD29,CD44 and CD105.but negative for CD14,CD34,CD45,VLA-1 and HLA-DR.MTT detection demonstrated that human BMSCs were in the adaptive phase at days 1-3.and entered logarithmic phase frOm day 3.No significant difference was detected in human BMSCs on the monolayer polystyrene and cytodex3(P>0.05).On the monolayer polystyrene,human BMSCs entered degenerating stage from day 6,whereas on the cytodex3,human BMSCs were still in the logarithmic growth phase at day 9(P<0.05).Flow cytometry detection confirmed that the cell cycle of human BMSCs was the same both on the monolayer polystyrene and cytodex3 (P>0.05). CONCLUSION:Using cytodex3 culture technique,a large amount of human BMSCs can be obtained,and the proliferative activity of these BMSCs is good.
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Objective To explore the clinical significance and operational methods during extended radical excision for pancreatic cancer combined with portal vein ( PV )/superior mesentery vein ( SMV ) resection,and to investigate the management of iatrogenic arterial injury. Methods Clinical date of 242 patients with pancreatic cancer undergoing extended radical excision were retrospectively analyzed. All cases were divided into three groups, patients with PV/SMV resection were in group A (n = 51 ), patients with iatrogenic arterial injury during operation were in group B(n =5) ,patients without resection of vessels werein group C (n = 186 ). Operating time、volume of intraoperative blood transfusion, time of vascular interruption、the mean hospitalization,postoperative complications and postoperative survival analysis among three groups were compared with each other. Results Operating time in group A、B and C were (442. 85 ± 102. 32 ) min, ( 348. 62 ± 92. 31 ) min and ( 315.00 ± 83.43 ) min respectively, volume of intraoperative blood transfusion were ( 1430. 83 ± 1092. 43 ) ml、( 1420. 22 ± 794. 41 ) ml and ( 928. 19 ±571.57) ml respectively,operating time and volume of intraoperative blood transfusion were of significantly difference(P <0. 05) among the 3 groups,there was no significant difference in the mean hospitalization and postoperative complications. The postoperative median survival period was 18.4 months for patients of pancreatic adenocarcinoma with PV/SMV resection, the postoperative median survival period was 16. 1 months without PV/SMV resection, there was no significant difference between these by postoperative survival analysis. In the 51 cases with vessel resection,7 cases underwent partial resection of the vascular wall,44 cases underwent segmental resection, reconstruction of the portal vein was performed by end-to-end anastomosis in 38 patients, stent graft in 6 cases, the mean length of the PV/SMV resection was (2. 92 ±1.35 ) cm; latrngenic arterial injury occurred during operation in 5 patients ( 1 in hepatic artery, 1 in superior mesenteric artery, 3 in celiac think), the artery was reconstructed by end-to-end anastomosis in 4 cases,repair in 1 case. Conclusions Active and reasonable operation for pancreatic cancer with PV/SMV resection is important for improving the rate of surgical resection and the quality of life. Because of complex topography,iatrogenic vascular injury may happened frequently.
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BACKGROUND: Hepatocyte/polymer interface with good biocompatibility is the key factor in bioreactor design andconstruction, however, bioreactor used in the clinical practice currently is not an ideal one.OBJECTIVE: To establish human hepatocyte compatible polypropylene interface and to lay a foundation for establishingbioartificial liver reactor with polypropylene hollow fiber.DESIGN, TIME AND SETTING: The comparative observation, cell compatibility experiment was performed betweenFebruary and October 2003 at Shanghai Jiao Tong University, Shanghai, China.MATERIALS: Polypropylene Photochemical graft polymerization modification technique was used to graft hydrophilicacrylamide groups on the surface of polypropylene membrane by chemical bonds to form modified polypropylenemembrane.METHODS: L02 human hepatoeytes were seeded on polypropylene membrane, modified polypropylene membrane andpolystyrene membrane, and polystyrene membrane was used as normal control.MAIN OUTCOME MEASURES: Static water contact angle of polypropylene membrane before and after graftmodification; morphology, adherent rate and proliferation activity of L02 human hepatocytes on different material surfaces.RESULTS: Static water contact angle after polypropylene membrane graft modification was smaller than that before graftmodification (P < 0.05). The adherent rate of L02 human hepatocytes on the surface of modified polypropylene membranewas 0, and the proliferation activity of them, which grew as spherical aggregates, was markedly higher than that of cells onpolystyrene membrane and polypropylene membrane without graft modification.CONCLUSION: Grafting polyacrylamide on the surface of polypropylene can establish good interface of L02 humanhepatocytes/polypropylene and form hepatocyte spherical aggregates through simple static culture.
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Objective To study the clinical characteristics and diagnosis of the solid-psendopapillary tumor of pancreas (SPT).Methods The clinical data of 40 SPT from January 1996 to January 2008 were retrospectively analyzed. The average age was (32.9 + 13.6 )years. The average clinical course was (8.6±0.1) months.Clinical symptoms usually included distensible pains and secret anguish in abdomen (60.0%).No jaundice appeared in any case.Results The surgical resection was favorable for the treatment of SPT,which had excellent prognosis.No tumor recurrence were found in those following-up patients. Grossly,the cut surface showed areas of solid and papillary tissue,cystic degeneration,hemorrhage,and necrosis.Pathological features included a combination of solid and cystic components with pseudopapillae formation and degenerative regions without glands.Conclusions SPT has its uniquely clinical and pathological characteristics.Its main diagnosed points are helpful for clinical doctors to make timely diagnosis and reduce the rate of misdiagnosis and mistreatment.
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Objective To improve the diagnosis and management of solid-pseudopapillary tumor (SPT) of the pancreas. MethodsTwenty-two SPT patients were retrospectively reviewed and divided into two groups, misdiagnosed group and those with preoperatively correct diagnosis. ResultsAbout one half (46%) SPT cases were misdiagnosed preoperatively. With time SPT tends to invade its capsule resulting in impossibility of radical resection, and increased medical expenses. ConclusionsAlthough SPT is of low degree malignant, and the prognosis after surgical resection is satisfactory, misdiagnosis and preoperative misdiagnosis and inappropriate management still cost the patients increased expenses and inhospital stay.