Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to b...Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey the Von Mises yield criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by-step manner,updating the coordinates of material points and the property after each step, so that both nonsteady-state and stendy-state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analys- is.Predicted the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.展开更多
AIM： To investigate the effect of activation of canonical Wnt signaling pathway on the proliferation and differentiation of hepatic oval cells in vitro. METHODS： WB-F344 cells were treated with recombinant Wnt3a （2...AIM： To investigate the effect of activation of canonical Wnt signaling pathway on the proliferation and differentiation of hepatic oval cells in vitro. METHODS： WB-F344 cells were treated with recombinant Wnt3a （20, 40, 80, 160, 200 ng/mL） in serum-free medium for 24 h. Cell proliferation was measured by Brdu incorporation analysis; untreated WB-F344 cells were taken as controls. After treatment with Wnt3a （160 ng/mL） for 24 h, subcellular localization and protein expression of p-catenin in WB-F344 cells treated and untreated with Wnt3a were examined by immunofluorescence staining and Western blot analysis. CyclinD1 mRNA expression was determined by semi-quantitative reverse-transcript polymerase chain reaction （RT-PCR）. The mRNA levels of some phenotypic markers （AFP, CK-19, ALB） and two hepatic nuclear factors （HNF-4, HIVF-6） were measured by RT-PCR. Expressions of CK-19 and AFP protein were detected by Western blot analysis. RESULTS： Wnt3a promoted proliferation of WB-F344 cells. Stimulation of WB-F344 cells with recombinant Wnt3a resulte^l in accumulation of the transcriptional activator β-catenin, together with its translocation into the nuclei, and up-regulated typical Wnt target gene CyclinD1. After 3 d of Wnt3a treatment in the absence of serum, WB-F344 cells retained their bipotential to express several specific phenotypic markers of hepatocytes and cholangiocytes, such as AFP and CK-19, following activation of the canonical Wnt signaling pathway. CONCLUSION： The canonical Wnt signaling pathway promotes proliferation and self-renewal of rat hepatic oval cells.展开更多
AIM： To elucidate the interaction between non- parenchymal cells, extracellular matrix and oval cells during the restituting process of liver injury induced by partial hepatectomy （PH）. METHODS： We examined the lo...AIM： To elucidate the interaction between non- parenchymal cells, extracellular matrix and oval cells during the restituting process of liver injury induced by partial hepatectomy （PH）. METHODS： We examined the localization of oval cells, non-parenchymal cells, and the extracellular matrix components using immunohistochemical and double immunofluorescent analysis during the proliferation and differentiation of oval cells in N-2- acetylaminofluorene （2-AAF）/PH rat model. RESULTS： By day 2 after PH, small oval cells began to proliferate around the portal area. Most of stellate cells and laminin were present along the hepatic sinusoids in the periportal area. Kupffer cells and fibronectin markedly increased in the whole hepatic Iobule. From day 4 to 9, oval cells spread further into hepatic parenchyma, closely associated with stellate cells, fibronectin and laminin. Kupffer cells admixed with oval cells by day 6 and then decreased in the periportal zone. From day 12 to 15, most of hepatic stellate cells （HSCs）, laminin and fibronectin located around the small hepatocyte nodus, and minority of them appeared in the nodus. Kupffer cells were mainly limited in the pericentral sinusoids. After day 18, the normal liver Iobule structures began to recover.CONCLUSION： Local hepatic microenvironment may participate in the oval cell-mediated liver regeneration through the cell-cell and cell-matrix interactions.展开更多
AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 l...AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.展开更多
OBJECTIVE: To study the relationship between oval cells and primary hepatocarcinoma and the expression of c-kit and proliferating cell nuclear antigen (PCNA) in oval cells of rats with hepatocellular carcinoma. METHOD...OBJECTIVE: To study the relationship between oval cells and primary hepatocarcinoma and the expression of c-kit and proliferating cell nuclear antigen (PCNA) in oval cells of rats with hepatocellular carcinoma. METHODS: A hundred and twenty clean SD rats were divided into three groups: normal group, cancer-induction group and intervention group. The normal group was fed with standard forage while the rest two groups were fed with 3'-methyl-2-methylamino-azobenzene (DAB) to induce carcinoma for 14 weeks and then fed with standard forage and water. Uscharidin was injected abdominally to the intervention group from the first week to the 14th week. All rats were killed and biopsy specimens were taken from the left and right liver lobes for immunohistochemical staining of c-kit and PCNA on the 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th, 22nd, and 24th week. RESULTS: From the 2nd to 14th week after liver infection, c-kit positive cells, mainly oval cells were found in the portal area in the carcinoma-induction group and dotted positive pigmentations in liver lobules. In the 22nd week, a large number of cancerous nodes occurred and nuclei heteromorphi-m was apparent; the number of positive cell decreased but positive cells could be sparsely observed in cancerous nodes. In the 2nd week of the carcinoma-induction process, PCNA positive cells were oval cells in the portal area. In the 4th week, a lot of hepatic cells were positively stained, especially in the central vein area. In the 6th week, PCNA positive cells could be seen in the lobules of the liver. In the 8th week, the number of PCNA cells decreased comparatively. From the 10th to 14th week, oval cells in the portal area were still over-expressed. From the 16th to 24th week, a large number of cancerous nodes occurred and PCNA was over-expressed in some of them. In necrotic cancerous nodes, the para-cancerous PCNA positive cells were sparsely distributed and their number was less than that of PCNA positive cells of cancerous tissues. CONCLUSIONS: Hepatic展开更多
BACKGROUND: This study was designed to assess theroles of oval cells and c-myc mRNA in the process of hepa-tocarcinogenesis and to clarify the function of carcinogenec-myc in the development of hepatocellular carcinom...BACKGROUND: This study was designed to assess theroles of oval cells and c-myc mRNA in the process of hepa-tocarcinogenesis and to clarify the function of carcinogenec-myc in the development of hepatocellular carcinoma( HCC) and the mechanism of inhibitory function of uscha-ridin on HCC in mouse hepatocarcinogenesis.METHODS: A total of 120 clean SD mice were divided intonormal group, cancer induction group, and interventiongroup. The normal group was fed with standard foragewhile the rest two groups were given p-dimethylaminoazo-benzene (DAB) to induce cancer. Thirteen weeks after in-duction of cancer, the two groups were fed with standardforage and water. Once the pattern was set up, the inter-vention group was given uscharidin injection into the ab-dominal cavity from the first week to the 14th week. Onthe 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th,22nd, and 24th week, all mice were killed and biopsiedfrom the liver lobe for pathological analysis. At the sametime, the number of tumor nodes was counted and the ex-pression of c-myc mRNA was tested by RT-PCR.RESULTS: Since the 2nd week after cancer induction, pro-liferated oval cells could be seen in the portal area. Initially,the oval cells appeared in the cortical layer of the portalarea, then proliferated gradually and immigrated into theliver parenchyma. In the period of fibrosis after liver proli-feration, proliferated heaps of oval cells were noted in bothportal and peripheral areas. In the period of carcinomatouschange, oval cells could be seen both outside and inside ofcancer nodes, but most of them were distributed outside.The c-myc gene was expressed negatively in the liver tissueof mice. The quantity of the expression began to increaseat the time of infection of the liver and tended to increasewith the degree of hepatic injury. In the period of cancera-tion, the expression level of c-myc mRNA increased gra-dually. The intervention of uscharidin could not inhibit butdelay the increase of the expression of c-myc mRNA.CONCLUSION: Oval cells are展开更多
AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GF...AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GFP） or 5, 6- carboxyfluorescein diacetate succinmidyl ester （CFDASE）. Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA- SE labeled HOC （5 × 10^6 cells each rat） were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin （ALB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and total bilirubin （TBil） levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.RESULTS： The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 （9/15 vs 6/15） and 72 h （9/15 vs 4/15） after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum AIb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.CONCLUSION： CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.展开更多
AIM： To investigate whether Thyl recognizes oval cells in the fetal liver and to characterize the cultured Thy1 selected cells from E14 rat livers. METHODS： Thyl populations were analyzed by fluorescence activated c...AIM： To investigate whether Thyl recognizes oval cells in the fetal liver and to characterize the cultured Thy1 selected cells from E14 rat livers. METHODS： Thyl populations were analyzed by fluorescence activated cell sorter analysis. Thyl positive cells were isolated using magnetic beads. Hepatic markers were detected by Western blotting, immunocytochemistry and RT-PCR. RESULTS： The percentage of Thyl-positive cells decreased during early development of fetal rat liver （E13-E16）. E14 fetal livers contained 7.8% Thy1 positive cells, of which 61% were positive for α-fetoprotein （AFP） and 25% expressed albumin. The Thy1＋ population expressed oval cell markers c-Kit and CXCR4, liver enriched-transcription factors HNF1α and HNF6, hepatocytic markers albumin, AFP and cytokeratin 18, and biliary marker cytokeratin 19. Thy1- selected cells formed only mesenchymal colonies when plated on collagen and in serum-containing media. Thyl selected cells were able to form hepatic colonies positive for HNF1α, HNF6, albumin, AFP, cytokeratin 18, cytokeratin 19 and glycogen, when grown on STO feeder layers in serum free-media. CONCLUSION： Oval cells positive for Thyl are present in early liver embryonic stages.展开更多
AIM:To investigate the ultrastructure of oval cells in children with chronic hepatitis B,with special emphasis on their location in areas of collagen fibroplasia. METHODS:Morphological investigations were conducted on...AIM:To investigate the ultrastructure of oval cells in children with chronic hepatitis B,with special emphasis on their location in areas of collagen fibroplasia. METHODS:Morphological investigations were conducted on biopsy material obtained from 40 children,aged 3-16 years with chronic hepatitis B. The stage of fibrosis was assessed histologically using the arbitrary semiquantitative numerical scoring system proposed by Ishak et al. The material for ultrastructural investigation was fixed in glutaraldehyde and paraformaldehyde and processed for transmission-electron microscopic analysis. RESULTS:Ultrastructural examination of biopsy specimens obtained from children with chronic hepatitis B showed the presence of two types of oval cells,the hepatic progenitor cells and intermediate hepatic-like cells. These cells were present in the parenchyma and were seen most commonly in areas of intense periportal fibrosis (at least stage 2 according to Ishak et al) and in the vicinity of the limiting plate of the lobule. The activated nonparenchymal hepatic cells,i.e. transformed hepatic stellate cells and Kupffer cells were seen in close proximity to the intermediate hepatic-like cells. CONCLUSION:We found a distinct relationship between the prevalence of oval cells (hepatic progenitor cells and intermediate hepatocyte-like cells) and fibrosis stage in pediatric patients with chronic hepatitis B.展开更多
The liver possesses an extraordinary ability to regenerate after injury.Hepatocyte-driven liver regeneration is the default pathway in response to mild-to-moderate acute liver damage.When replication of mature hepatoc...The liver possesses an extraordinary ability to regenerate after injury.Hepatocyte-driven liver regeneration is the default pathway in response to mild-to-moderate acute liver damage.When replication of mature hepatocytes is blocked,facultative hepatic progenitor cells(HPCs),also referred to as oval cells(OCs)in rodents,are activated.HPC/OCs have the ability to proliferate clonogenically and differentiate into several lineages including hepatocytes and bile ductal epithelia.This is a conserved liver injury response that has been studied in many species ranging from mammals(rat,mouse,and human)to fish.In addition,improper HPC/OC activation is closely associated with fibrotic responses,characterized by myofibroblast activation and extracellular matrix production,in many chronic liver diseases.Matrix remodeling and metalloprotease activities play an important role in the regulation of HPC/OC proliferation and fibrosis progression.Thus,understanding molecular mechanisms underlying HPC/OC activation has therapeutic implications for rational design of anti-fibrotic therapies.展开更多
Objective: To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window(OW).Methods: Data from three cases with OW atresia, malformed stapes and abnormal facial ner...Objective: To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window(OW).Methods: Data from three cases with OW atresia, malformed stapes and abnormal facial nerve courses were reported, in which a scala tympani drill-out technique was employed with a TORP between the tympanic membrane and scala tympani fenestration for hearing reconstruction.Results: Air conduction hearing improved in two of the three cases following surgery. In the third case, there was no improvement in air conduction hearing following a canal wall up mastoidectomy and tympanoplasty. There were no vertigo, tinnitus or sensorineural hearing loss in the three cases.Conclusion: The scala tympani drill-out technique, which is basically fenestration at the initial part of the basal turn, provides a choice in hearing reconstruction when the OW is completely covered by abarrently coursed facial nerve.展开更多
文摘Three dimensional thermal-mechanical coupled elasto-plastic FEM has been used for simulation of round to oval single pass rolling. The analysis was conducted using MARC/AUTOFORCE1. 2 code. The material is assumed to be elasto-plastic and it obey the Von Mises yield criterion and Prandtl- Reuss rule. Deformation of the workpiece is simulated in a step-by-step manner,updating the coordinates of material points and the property after each step, so that both nonsteady-state and stendy-state deformation can be simulated. The heat transfter between the workpiece, the rolls, and enviroment and the heat generation due to plastic work and friction force, are considered in the analys- is.Predicted the deformation shape of the workpiece, distributions of strains, stresses, strain rates and temperatures, roll-separating force and roll torque are presented.
文摘AIM： To investigate the effect of activation of canonical Wnt signaling pathway on the proliferation and differentiation of hepatic oval cells in vitro. METHODS： WB-F344 cells were treated with recombinant Wnt3a （20, 40, 80, 160, 200 ng/mL） in serum-free medium for 24 h. Cell proliferation was measured by Brdu incorporation analysis; untreated WB-F344 cells were taken as controls. After treatment with Wnt3a （160 ng/mL） for 24 h, subcellular localization and protein expression of p-catenin in WB-F344 cells treated and untreated with Wnt3a were examined by immunofluorescence staining and Western blot analysis. CyclinD1 mRNA expression was determined by semi-quantitative reverse-transcript polymerase chain reaction （RT-PCR）. The mRNA levels of some phenotypic markers （AFP, CK-19, ALB） and two hepatic nuclear factors （HNF-4, HIVF-6） were measured by RT-PCR. Expressions of CK-19 and AFP protein were detected by Western blot analysis. RESULTS： Wnt3a promoted proliferation of WB-F344 cells. Stimulation of WB-F344 cells with recombinant Wnt3a resulte^l in accumulation of the transcriptional activator β-catenin, together with its translocation into the nuclei, and up-regulated typical Wnt target gene CyclinD1. After 3 d of Wnt3a treatment in the absence of serum, WB-F344 cells retained their bipotential to express several specific phenotypic markers of hepatocytes and cholangiocytes, such as AFP and CK-19, following activation of the canonical Wnt signaling pathway. CONCLUSION： The canonical Wnt signaling pathway promotes proliferation and self-renewal of rat hepatic oval cells.
基金Supported by A grant from National Natural Science Foundation of China
文摘AIM： To elucidate the interaction between non- parenchymal cells, extracellular matrix and oval cells during the restituting process of liver injury induced by partial hepatectomy （PH）. METHODS： We examined the localization of oval cells, non-parenchymal cells, and the extracellular matrix components using immunohistochemical and double immunofluorescent analysis during the proliferation and differentiation of oval cells in N-2- acetylaminofluorene （2-AAF）/PH rat model. RESULTS： By day 2 after PH, small oval cells began to proliferate around the portal area. Most of stellate cells and laminin were present along the hepatic sinusoids in the periportal area. Kupffer cells and fibronectin markedly increased in the whole hepatic Iobule. From day 4 to 9, oval cells spread further into hepatic parenchyma, closely associated with stellate cells, fibronectin and laminin. Kupffer cells admixed with oval cells by day 6 and then decreased in the periportal zone. From day 12 to 15, most of hepatic stellate cells （HSCs）, laminin and fibronectin located around the small hepatocyte nodus, and minority of them appeared in the nodus. Kupffer cells were mainly limited in the pericentral sinusoids. After day 18, the normal liver Iobule structures began to recover.CONCLUSION： Local hepatic microenvironment may participate in the oval cell-mediated liver regeneration through the cell-cell and cell-matrix interactions.
文摘AIM: To detect immunohistochemically the presence of oval cells in chronic viral hepatitis with antibody against c-kit. METHODS: We detected oval cells in paraffin embedded liver sections of 3 normal controls and 26 liver samples from patients with chronic viral hepatitis, using immunohistochemistry with antibodies against c-kit, piclass glutathione S-transferase (pi-GST) and cytokeratins 19 (CK19). RESULTS: Oval cells were not observed in normal livers. In chronic viral hepatitis, hepatic oval cells were located predominantly in the periportal region and fibrosis septa,characterized by an ovoid nucleus, small size,and scant cytoplasm. Antibody against stem cell factor receptor, c-kit, had higher sensitivity and specificity than pi-GST and CK19. About 50%-70% of c-kit positive oval cells were stained positively for either pi-GST or CK19. CONCLUSION: Oval cells are frequently detected in human livers with chronic viral hepatitis, suggesting that oval cell proliferation is associated with the liver regeneration in this condition.
基金This work was supported by the grants from Science Foundation of Guangdong Province (No. 00593 and 01059. 2001).
文摘OBJECTIVE: To study the relationship between oval cells and primary hepatocarcinoma and the expression of c-kit and proliferating cell nuclear antigen (PCNA) in oval cells of rats with hepatocellular carcinoma. METHODS: A hundred and twenty clean SD rats were divided into three groups: normal group, cancer-induction group and intervention group. The normal group was fed with standard forage while the rest two groups were fed with 3'-methyl-2-methylamino-azobenzene (DAB) to induce carcinoma for 14 weeks and then fed with standard forage and water. Uscharidin was injected abdominally to the intervention group from the first week to the 14th week. All rats were killed and biopsy specimens were taken from the left and right liver lobes for immunohistochemical staining of c-kit and PCNA on the 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th, 22nd, and 24th week. RESULTS: From the 2nd to 14th week after liver infection, c-kit positive cells, mainly oval cells were found in the portal area in the carcinoma-induction group and dotted positive pigmentations in liver lobules. In the 22nd week, a large number of cancerous nodes occurred and nuclei heteromorphi-m was apparent; the number of positive cell decreased but positive cells could be sparsely observed in cancerous nodes. In the 2nd week of the carcinoma-induction process, PCNA positive cells were oval cells in the portal area. In the 4th week, a lot of hepatic cells were positively stained, especially in the central vein area. In the 6th week, PCNA positive cells could be seen in the lobules of the liver. In the 8th week, the number of PCNA cells decreased comparatively. From the 10th to 14th week, oval cells in the portal area were still over-expressed. From the 16th to 24th week, a large number of cancerous nodes occurred and PCNA was over-expressed in some of them. In necrotic cancerous nodes, the para-cancerous PCNA positive cells were sparsely distributed and their number was less than that of PCNA positive cells of cancerous tissues. CONCLUSIONS: Hepatic
基金This work was supported by two grants from the Science Fundation ofGuangdong Province, China (No. 010593 No. 020097).
文摘BACKGROUND: This study was designed to assess theroles of oval cells and c-myc mRNA in the process of hepa-tocarcinogenesis and to clarify the function of carcinogenec-myc in the development of hepatocellular carcinoma( HCC) and the mechanism of inhibitory function of uscha-ridin on HCC in mouse hepatocarcinogenesis.METHODS: A total of 120 clean SD mice were divided intonormal group, cancer induction group, and interventiongroup. The normal group was fed with standard foragewhile the rest two groups were given p-dimethylaminoazo-benzene (DAB) to induce cancer. Thirteen weeks after in-duction of cancer, the two groups were fed with standardforage and water. Once the pattern was set up, the inter-vention group was given uscharidin injection into the ab-dominal cavity from the first week to the 14th week. Onthe 2nd, 4th, 6th, 8th, 10th, 12th, 14th, 16th, 18th, 20th,22nd, and 24th week, all mice were killed and biopsiedfrom the liver lobe for pathological analysis. At the sametime, the number of tumor nodes was counted and the ex-pression of c-myc mRNA was tested by RT-PCR.RESULTS: Since the 2nd week after cancer induction, pro-liferated oval cells could be seen in the portal area. Initially,the oval cells appeared in the cortical layer of the portalarea, then proliferated gradually and immigrated into theliver parenchyma. In the period of fibrosis after liver proli-feration, proliferated heaps of oval cells were noted in bothportal and peripheral areas. In the period of carcinomatouschange, oval cells could be seen both outside and inside ofcancer nodes, but most of them were distributed outside.The c-myc gene was expressed negatively in the liver tissueof mice. The quantity of the expression began to increaseat the time of infection of the liver and tended to increasewith the degree of hepatic injury. In the period of cancera-tion, the expression level of c-myc mRNA increased gra-dually. The intervention of uscharidin could not inhibit butdelay the increase of the expression of c-myc mRNA.CONCLUSION: Oval cells are
基金Supported by Tianjin Science Committee,Grant No.05SYSYJC02600Tianjin Health Bureau,Grant No.05KYR01
文摘AIM： To evaluate the effect of intrahepatic transplantation of hepatic oval cells （HOC） on fulminant hepatic failure （FHF） in rats.METHODS： HOC obtained from rats were labeled with green fluocescent protein （GFP） or 5, 6- carboxyfluorescein diacetate succinmidyl ester （CFDASE）. Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA- SE labeled HOC （5 × 10^6 cells each rat） were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin （ALB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and total bilirubin （TBil） levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.RESULTS： The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 （9/15 vs 6/15） and 72 h （9/15 vs 4/15） after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum AIb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.CONCLUSION： CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.
基金Supported by the Genesis Consortium for Cell Therapy, Israel Ministry of Science
文摘AIM： To investigate whether Thyl recognizes oval cells in the fetal liver and to characterize the cultured Thy1 selected cells from E14 rat livers. METHODS： Thyl populations were analyzed by fluorescence activated cell sorter analysis. Thyl positive cells were isolated using magnetic beads. Hepatic markers were detected by Western blotting, immunocytochemistry and RT-PCR. RESULTS： The percentage of Thyl-positive cells decreased during early development of fetal rat liver （E13-E16）. E14 fetal livers contained 7.8% Thy1 positive cells, of which 61% were positive for α-fetoprotein （AFP） and 25% expressed albumin. The Thy1＋ population expressed oval cell markers c-Kit and CXCR4, liver enriched-transcription factors HNF1α and HNF6, hepatocytic markers albumin, AFP and cytokeratin 18, and biliary marker cytokeratin 19. Thy1- selected cells formed only mesenchymal colonies when plated on collagen and in serum-containing media. Thyl selected cells were able to form hepatic colonies positive for HNF1α, HNF6, albumin, AFP, cytokeratin 18, cytokeratin 19 and glycogen, when grown on STO feeder layers in serum free-media. CONCLUSION： Oval cells positive for Thyl are present in early liver embryonic stages.
文摘AIM:To investigate the ultrastructure of oval cells in children with chronic hepatitis B,with special emphasis on their location in areas of collagen fibroplasia. METHODS:Morphological investigations were conducted on biopsy material obtained from 40 children,aged 3-16 years with chronic hepatitis B. The stage of fibrosis was assessed histologically using the arbitrary semiquantitative numerical scoring system proposed by Ishak et al. The material for ultrastructural investigation was fixed in glutaraldehyde and paraformaldehyde and processed for transmission-electron microscopic analysis. RESULTS:Ultrastructural examination of biopsy specimens obtained from children with chronic hepatitis B showed the presence of two types of oval cells,the hepatic progenitor cells and intermediate hepatic-like cells. These cells were present in the parenchyma and were seen most commonly in areas of intense periportal fibrosis (at least stage 2 according to Ishak et al) and in the vicinity of the limiting plate of the lobule. The activated nonparenchymal hepatic cells,i.e. transformed hepatic stellate cells and Kupffer cells were seen in close proximity to the intermediate hepatic-like cells. CONCLUSION:We found a distinct relationship between the prevalence of oval cells (hepatic progenitor cells and intermediate hepatocyte-like cells) and fibrosis stage in pediatric patients with chronic hepatitis B.
文摘The liver possesses an extraordinary ability to regenerate after injury.Hepatocyte-driven liver regeneration is the default pathway in response to mild-to-moderate acute liver damage.When replication of mature hepatocytes is blocked,facultative hepatic progenitor cells(HPCs),also referred to as oval cells(OCs)in rodents,are activated.HPC/OCs have the ability to proliferate clonogenically and differentiate into several lineages including hepatocytes and bile ductal epithelia.This is a conserved liver injury response that has been studied in many species ranging from mammals(rat,mouse,and human)to fish.In addition,improper HPC/OC activation is closely associated with fibrotic responses,characterized by myofibroblast activation and extracellular matrix production,in many chronic liver diseases.Matrix remodeling and metalloprotease activities play an important role in the regulation of HPC/OC proliferation and fibrosis progression.Thus,understanding molecular mechanisms underlying HPC/OC activation has therapeutic implications for rational design of anti-fibrotic therapies.
文摘Objective: To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window(OW).Methods: Data from three cases with OW atresia, malformed stapes and abnormal facial nerve courses were reported, in which a scala tympani drill-out technique was employed with a TORP between the tympanic membrane and scala tympani fenestration for hearing reconstruction.Results: Air conduction hearing improved in two of the three cases following surgery. In the third case, there was no improvement in air conduction hearing following a canal wall up mastoidectomy and tympanoplasty. There were no vertigo, tinnitus or sensorineural hearing loss in the three cases.Conclusion: The scala tympani drill-out technique, which is basically fenestration at the initial part of the basal turn, provides a choice in hearing reconstruction when the OW is completely covered by abarrently coursed facial nerve.
