Usefulness of a Vascular Clipping System to Create an Arteriovenous Fistula

Purpose@#The vascular clipping system (VCS) is beneficial as it is simple and easy to apply for microvascular suturing. Arteriovenous fistula (AVF) creation is a very basic standard technique of microvascular surgery. In this study the VCS and the conventional suture methods were compared in a rabbit model using the carotid artery and vein to create an AVF. @*Methods@#There were 28 rabbits assigned equally into 2 groups using the AVF creation method (conventional suturing or the VCS procedure). Histopathology was performed on fixed samples. The procedure time of the 2 methods and changes in histopathology of tissue samples after surgery were compared. @*Results@#The VCS procedure showed a lower degree of fibrosis and hyperplasia histologically compared with the conventional suture method. The VCS was quicker to perform and no significant anastomosis stricture was observed. @*Conclusion@#In a rabbit model of AVF, the VCS has benefits over the conventional suture method. The VCS provides comparable patency rates, produces fewer side effects such as fibrosis and hyperplasia, and takes less operation time than suturing. The VCS is expected to be useful for cases where renal patients need periodic hemodialysis and thus repetitive access to a vessel.

Usefulness of a Vascular Clipping System to Create an Arteriovenous Fistula

Purpose@#The vascular clipping system (VCS) is beneficial as it is simple and easy to apply for microvascular suturing. Arteriovenous fistula (AVF) creation is a very basic standard technique of microvascular surgery. In this study the VCS and the conventional suture methods were compared in a rabbit model using the carotid artery and vein to create an AVF. @*Methods@#There were 28 rabbits assigned equally into 2 groups using the AVF creation method (conventional suturing or the VCS procedure). Histopathology was performed on fixed samples. The procedure time of the 2 methods and changes in histopathology of tissue samples after surgery were compared. @*Results@#The VCS procedure showed a lower degree of fibrosis and hyperplasia histologically compared with the conventional suture method. The VCS was quicker to perform and no significant anastomosis stricture was observed. @*Conclusion@#In a rabbit model of AVF, the VCS has benefits over the conventional suture method. The VCS provides comparable patency rates, produces fewer side effects such as fibrosis and hyperplasia, and takes less operation time than suturing. The VCS is expected to be useful for cases where renal patients need periodic hemodialysis and thus repetitive access to a vessel.

Protective effect of ischemic postconditioning against hepatic ischemic reperfusion injury in rat liver

PURPOSE: The efficiency of ischemic postconditioning (IPC) was evaluated in a rat model of ischemic liver. Concentration of survivin of liver tissue correlated with the degree of antiapoptosis, so survivin was estimated to evaluate the efficiency of IPC on ischemic reperfusion (IR) injury. METHODS: Twenty-four healthy rats were divided to three groups (SHAM, IR, and IPC). Rats in the SHAM group displayed no change during 3 hours. Rats in the IR group were ischemic within 1 hour of clamping the left hepatic artery and left portal vein. Reperfusion for 2 hours was then done. IPC group, intermittent 2, 3, 5, and 7 minutes of reperfusion followed by 1 hour of warm ischemia. Two-minute reocclusion was done after each reperfusion. Rat sera were analyzed for AST and ALT, and Western blot analysis of rat liver tissue of rats evaluated malondialdehyde (MDA) and survivin. RESULTS: MDA in the liver tissue of rats in the IR and IPC group were significantly high than in the liver tissue of the SHAM group (P = 0.003 and P = 0.008, respectively). Survivin was higher in the IPC group than in the SHAM and IR groups (P = 0.021 and P = 0.024, respectively). CONCLUSION: IPC could not prevent lipid oxidation in liver cell mitochondria, but did aid in the regeneration of ischemic injured liver cells. The results indicate that IPC can suppress the apoptosis of liver cells and reduce reperfusion injury of liver tissue.

Effects of 17beta-Estradiol and Estrogen Receptor Antagonists on the Proliferation of Gastric Cancer Cell Lines

PURPOSE: The aims of this study were as follow: 1) to de scribe the expression status of estrogen receptor-alpha and -beta mRNAs in five gastric carcinoma cell lines; 2) to evaluate in vitro the effects of 17beta-estradiol and estrogen receptor antagonists on the proliferation of the cell lines. MATERIALS AND METHODS: Detection of estrogen receptor-alpha and estrogen receptor-beta mRNA in five human gastric cancer cell lines (AGS, KATO III, MKN28, MKN45 and MKN74) was made by the reverse transcription-polymerase chain reaction system. To evaluate the effect of 17beta-estradiol and estrogen receptor antagonists on the proliferation of gastric cancer cell line, the cell lines which expressed both es trogen receptors were chosen and treated with 17beta-estradiol and estrogen receptor antagonists (methyl-piperidino-pyrazole and pyrazolo [1,5-a] pyrimidine). Cell proliferation was assessed with the methylthiazol tetrazolium test. RESULTS: Estrogen receptor-alpha and estrogen receptor-beta mRNAs were expressed in three (KATO III, MKN28 and MKN45) and all of the five gastric cancer cell lines, respectively. At higher concentrations, 17beta-estradiol inhibited cell growth of MKN28, MKN45 and KATO III cell lines. Neither estrogen receptor-alpha nor estrogen receptor-beta antagonist blocked the anti-proliferative effect of 17beta-estradiol. CONCLUSIONS: Our results indicate that estrogen receptor-beta mRNAs are preferentially expressed in gastric cancers and also imply that hormone therapy rather than estrogen receptor blockers may be a useful strategy for the treatment of estrogen receptor-beta positive gastric cancer. Its therapeutic significance in gastric cancer are, however, limited until more evidence of the roles of estrogen receptors in the gastric cancer are accumulated.

Stem Cell In Adult Pancreas: Its Activation and Induction of Beta Cell Differentiation / 대한해부학회지

Stem cells in adult pancreas and their specific marker are poorly characterized. We hypothesized that pancreatic stem cells could evolve from the duct system in response to neogenic stimulation. Following partial pancreatectomy (Px), we found extensive formation of ductules consisting of nestin-positive epithelial cells with higher replicating ability in the neogenic foci after Px. The neogenic ductules were isolated for the culture of nestin-positive duct cells. These nestinpositive duct cells were numerous and displayed extensive self-replication in the duct cell explants, thus depicted as nestin-positive duct stem (NPDS) cells. Endocrine cells, mostly insulin cells were present in the explants at day 2 as single cells or as small clusters adjacent to the NPDS cells, and formed islet-like masses at day 3 of culture, implying islet cell differentiation from NPDS cells. We found transient up-regulation of PDX-1 expression by RT-PCR at day 3 after Px in pancreatic tissue. We investigated the effect of clusterin overexpression on differentiation of insulin beta cells from duct cells We found that the number of insulin producing cells increased 11.5 fold when clusterin was overexpressed. Insulin expression, both insulin mRNA and peptide levels, was increased in clusterin cDNA transfected cells. In conclusion, we suggest that NPDS cells could be generated from adult pancreas by neogenic motivations and they may differentiate into insulin-secreting-cells, and clusterin could stimulate not only differentiation of precursor cells in the pancreatic duct, but also proliferation of predifferentiated beta cells. Those differentiated beta cells are functional cells secreting insulin in response to glucose stimulation.