去氢骆驼蓬碱软膏对小鼠上皮细胞 有丝分裂及表皮角化的影响

了解去氢骆驼蓬碱软膏对雌激素周期小鼠阴道上皮模型及鼠尾鳞片表皮模型的作用，为开发新的治疗银屑病药物提供初步的实验依据。方法：制备雌激素周期小鼠阴道上皮模型及鼠尾鳞片表皮模型，用光学显微镜观察分析基底细胞中有丝分裂数及颗粒层鳞片数。结果；与对照组相比，去氢骆驼蓬碱软膏对两个实验模型的作用均存在显著差异（Ｐ＜０．０１）。结论：去氢骆驼蓬碱软膏能抑制增殖活跃的上皮细胞并促使表皮角化完全，起到治疗银屑病的作用。

创伤愈合中表皮再生机理的研究──Ⅱ甘氨酸对表皮细胞游走的影响

本文研究在细胞培养基中加入不同浓度的甘氨酸，进行新生小鼠皮肤培养，然后测定培养０、２４、４８、７２ｈ后的表皮细胞游走的长度，结果表明甘氨酸可以促进表皮细胞的游走，其在创伤愈合初期起积极作用。

肝细胞癌小上皮细胞白蛋白和CK7的表达

目的探讨人类肝癌肝组织是否存在小上皮细胞 (smallepithelialcell,SEC) ,这类细胞是否表达白蛋白CK7双重免疫表型。 方法用肝细胞分化标记白蛋白和胆管上皮分化标记CK7抗体 ,对 30例人肝细胞肝癌的手术标本材料作免疫组化染色 ,对其中 10例作超微结构观察和白蛋白及CK7的免疫电镜标记。 结果 30例中有2 0例在肝癌肿瘤边缘和增生的小胆管发现有少量SEC。这类细胞既表达白蛋白 ,又表达CK7。电镜下 ,这类SEC体积较小 ,核大 ,胞质少 ,胞质内主要为游离核糖体 ,并有胞质内张力微丝及细胞间连接结构。免疫电镜下 ,10例中有5例可显示在同一SEC同时表达白蛋白和CK7。 结论人肝细胞肝癌肝中确实存在SEC。这类SEC具有与人肝母细胞瘤和胆道闭锁肝组织中的SEC一样的形态和免疫表型特点。

大鼠去卵巢前后血清雌二醇浓度变化及其对输卵管粘膜上皮的影响

目的 研究哺乳动物血清雌二醇与输卵管粘膜上皮细胞高度之间的相关性。 方法 据阴道涂片检查将动物分为 :动情间期 (DE)组 ,动情前期 (PE)组 ,动情期 (E)组 ,动情后期 (ME)组和去卵巢 (OVX)组 ,用放射免疫法检测各组大鼠血清雌二醇浓度 ,同时在光镜下对输卵管壶腹部、峡部的形态结构进行测量分析。 结果 大鼠血清雌二醇浓度依次为 :动情期组 >动情前期组 >动情后期组 >动情间期组 >去卵巢组 ,各组间差异均有显著性 ;输卵管粘膜上皮高度在动情周期中变化为 :动情期组 >动情前期组 >动情间期组 >动情后期组 ;去卵巢后 ,输卵管粘膜上皮萎缩。 结论 上述两项检测结果经回归分析发现 ,从动情间期至动情前期再至动情期两者呈正相关。

Effect of acetyl L-carnitine on human retinal pigment epithelium-19 cells in hypoxic conditions

AIM:To investigate the effect of acetyl-L-carnitine(ALCAR)on cell viability,morphological integrity,and vascular endothelial growth factor(VEGF)expression in human retinal pigment epithelium(ARPE-19)cells using a hypoxic model.METHODS:In the first set of experiments,the optimal CoCl_(2) dose was determined by exposing ARPE-19 cell cultures to different concentrations.To evaluate the effect of ALCAR on cell viability,five groups of ARPE-19 cell culture were established that included a control group,a sham group(200μM CoCl_(2)),and groups that received 1,10 and 100 mM doses of ALCAR combined with 200μM CoCl_(2),respectively.The cell viability was measured by MTT assay.The morphological characteristics of cells were observed by an inverted phase contrast microscope.The levels of VEGF and HIF-1α secretion by ARPE-19 cells were detected by enzyme linked immunosorbent assay(ELISA)assay.RESULTS:ARPE-19 cells were exposed to different doses of CoCl_(2) in order to create a hypoxia model.Nevertheless,when exposed to a concentration of 200μM CoCl_(2),a notable decrease in viability to 83% was noted.ALCAR was found to increase the cell viability at 1 mM and 10 mM concentrations,while the highest concentration(100 mM)did not have an added effect.The cell viability was found to be significantly higher in the groups treated with a concentration of 1 mM and 10 mM ALCAR compared to the Sham group(P=0.041,P=0.019,respectively).The cell viability and morphology remained unaffected by the greatest dose of ALCAR(100 mM).The administration of 10 mM ALCAR demonstrated a statistically significant reduction in the levels of VEGF and HIF-1α compared with the Sham group(P=0.013,P=0.033,respectively).CONCLUSION:The findings from the current study indicate that ALCAR could represent a viable therapeutic option with the potential to open up novel treatment pathways for retinal diseases,particular relevance for age-related macular degeneration(AMD).However,to fully elucidate ALCAR’s application potential in retinal diseases,additional investigation is necessary to clearly define the exact mechanisms involved.

Evidence of Casparian Strip in the Foliar Endodermis of Pinus bungeana

利用荧光显微镜对白皮松 (PinusbungeanaZucc.)针叶内皮层结构进行深入观察 ,确认内皮层径向壁和横向壁上具有能够激发荧光的带状结构 ;用纤维素酶和果胶酶对内皮层充分酶解分离后 ,首次从叶中得到类似于根部内皮层特有的网状结构 ;应用傅立叶变换红外光谱分光术 (FTIR)对网状结构进行化学成分鉴定 ,其吸收光谱的分析结果表明 ,针叶内皮层细胞壁带状结构部分含有木质素、木栓质、纤维素和细胞壁蛋白等 ,而这些成分与针叶维管组织的成分不尽相同。上述证据表明 ,白皮松针叶内皮层细胞壁具有与根部内皮层相似的凯氏带结构。

Leaf epidermal characters of Lonicera japonica and Lonicera confuse and their ecology adaptation

The leaf epidermis of Japanese honeysuckle （Lonicera japonica Thunb.） and Wild Honeysuckle （Lonicera confusa） in the genus of Flos Lonicerae were mainly observed by scanning electron microscopes （SEM） to study the characteristics of stomata, trichomes and dermal cell, etc.. The results showed that stoma exists only on the lower epidermis and its distribution is irregular, and leaf epidermis consist of epidermis cells, stoma complexes and bushy trichomes including glandular hair and non-glandular hair. On the upper epidermis, anticlinal wall caves in sinuous groove to countercheck the transpiration. Evidences from leaf morphological structures serve as another proof on drought-resistant mechanisms. Some strumaes distributing regularly are hypothesized as oxalic calcium on the lower epidermis under laser scanning confocal microscopy （LSCM） with Fluo-3/AM, which can increase their endurance to drought stress. Therefore, the above characteristics of Flos Lonicerae can reduce the loss of water and make Japanese honeysuckle and Wild Honeysuckle adapt to the droughty environment at Karst area in southwest China. However, there is some difference of the two species. From the SEM （Scanning Electron Microscopy） result, it is shown that on the upper epidermis, some glandular hair regularly present along the midrib of Japanese honeysuckle, but Wild Honeysuckle has no glandular hair on the upper epidermis, which can verify the relationships of Flos Lonicerae species and provide the significance for classification of Flos Lonicerae.

Hydroxysafflor Yellow A Promotes Vascular Endothelial Cell Proliferation via VEGF/VEGF Receptor

Aim To study the proliferative effeet of hydroxysaftlor yellow A （HSYA） on cultured canine aortic endothelial cell （VEC） in normoxic （21% O2 ） or hypoxic （10% O2 ） culture and the underlying mechanism. Methods The endothelial cells were scratched from trypsined canine aorta endothelium. HSYA was added to the cells at final concentrations of 1 × 10^-3, 1 × 10^-4 and 1 × 10^-5 mol· L^-1, respectively. VEGF （2.6 × 10^-7 mol· L^-1 ）-treated cells were used as the positive control. The proliferative effect of HSYA on VEC was determined at 48, 72, 96, and 120 h in normoxic culture by MTI＂ assay. Similarly, the proliferation of VEC was determined at 12, 24, 48, and 72 h in hypoxic culture by MTF assay. The effects of HSYA on VEC proliferation and VEGF secretion were investigated by MTr and ELISA assays at the presence of the antibodies to VEGF and VEGF receptors. Results Pretreatment with HSYA at concentrations of 1 × 10^-3 and 1 × 10^-4 mol· L^-1 enhanced VEC proliferation in normoxic culture. The most significant enhancing effect of HSYA on VEC proliferation was achieved at 24, 48, and 72 h in hypoxic culture in concentration-dependent and time-dependent manner. HSYA at 1 × 10^-3 mol·L^-1 showed a potency similar to VEGF at 2.6 × 10^-7 mol·L^-1 . Pretreatment with the antibodies of Flt-1, KDR or VEGF blocked the proliferative effect of HSYA with similar potencies. Antibodies of Fit-1 or VEGF antagonized the promoting effect of HSYA on VEGF secretion. Conclusion HSYA promotes VEC proliferation either in normoxic or hypoxic culture, especially in the latter condition. This effect of HSYA is at least partly mediated by VEGF and VEGF receptor.

MicroRNA let-7b targets important cell cycle molecules in malignant melanoma cells and interferes with anchorage-independent growth

A microRNA expression screen was performed analyzing 157 different microRNAs in laser-microdissected tissues from benign melanocytic nevi （n = 10） and primary malignant melanomas （n = 10）, using quantitative real-time PCR. Differential expression was found for 72 microRNAs. Members of the let-7 family of microRNAs were significantly downregulated in primary melanomas as compared with benign nevi, suggestive for a possible role of these molecules as tumor suppressors in malignant melanoma. Interestingly, similar findings had been described for lung and colon cancer. Overexpression of let-7b in melanoma cells in vitro downregulated the expression of cyclins D1, D3, and A, and cyclin-dependent kinase （Cdk） 4, all of which had been described to play a role in melanoma development. The effect oflet-7b on protein expression was due to targeting of 3＇-untranslated regions （3＇UTRs） of individual mRNAs, as exemplified by reporter gene analyses for cyclin D1. In line with its downmodulating effects on cell cycle regulators, let-7b inhibited cell cycle progression and anchorage-independent growth of melanoma cells. Taken together, these findings not only point to new regulatory mechanisms of early melanoma development, but also may open avenues for future targeted therapies of this tumor.

Involvement of aquaporins in a mouse model of rotavirus diarrhea

Rotavirus diarrhea is a major worldwide cause of infantile gastroenteritis; however, the mechanism responsible for intestinal fluid loss remains unclear. Water transfer across the intestinal epithelial membrane seems to occur because of aquaporins(AQPs). Accumulating evidence indicates that alterations in AQPs may play an important role in pathogenesis. Here, we focus on changes in AQPs in a mouse model of rotavirus diarrhea. In the present study, 32 of 35 mice developed diarrhea and mild dehydration within 24 hours after infection with rotavirus strain SA11. Intestinal epithelial cells demonstrated cytoplasmic vacuolation, malaligned villi, and atrophy. AQP1 expression was significantly attenuated in the ileum and colon in comparison with controls; likewise, AQP4 and-8 protein expression were significantly decreased in the colon of rotavirus diarrhea-infected mice. In contrast, AQP3 protein expression was significantly increased in the colon of rotavirus-infected mice in comparison with controls. These results indicate that rotavirus diarrhea is associated with the downregulation of AQP1,-4, and-8 expression. Therefore, AQPs play an important role in rotavirus diarrhea.

Long-term omeprazole and esomeprazole treatment does not significantly increase gastric epithelial cell proliferation and epithelial growth factor receptor expression and has no effect on apoptosis and p53 expression

AIM： To study the effect of proton pump inhibitor （PPI） treatment on patients with reflux esophagitis and its in vivo effect on apoptosis, p53- and epidermal growth factor receptor （EGFR） expression. METHODS： After informed consent was obtained, gastric biopsies of the antrum were taken from patients with reflux oesophagitis prior to and after 6 mo of 20 mg omeprazole （n = 24） or 40 mg esomeprazole （n = 22） therapy. Patients did not take any other medications known to affect the gastric mucosa. All patients were Helicobacter pylori negative as confirmed by rapid urease test and histology, respectively. Cell proliferation, apoptosis, EGFR, and p53 expression were measured by immunohistochemical techniques. At least 600 glandular epithelial cells were encountered and results were expressed as percentage of total cells counted. Was considered statistically significant. RESULTS： Although there was a trend towards increase of cell proliferation and EGFR expression both in omeprazole and esomeprazole treated group, the difference was not statistically significant. Neither apoptosis nor p53 expression was affected. CONCLUSION： Long-term PPI treatment does not significantly increase gastric epithelial cell proliferation and EGFR expression and has no effect on apoptosis and p53 expression.

Successful treatment of severe pouchitis with rebamipide refractory to antibiotics and corticosteroids:A case report

The antibiotics, metronidazole and ciprofloxacin, are the first-line treatment for pouchitis. Patients who do not respond to antibiotics or conventional medications represent a major challenge to therapy. In this report, we have described a successful treatment of severe refractory pouchitis with a novel agent, rebamipide, known to promote epithelial cell regeneration and angiogenesis. A 27-year-old male with ileo-anal pouch surgery presented with worsening anal pain, diarrhea, and abdominal pain. The patient was diagnosed to have pouchitis and was given metronidazole together with betamethasone enema （3.95 rag/dose）. However, despite this intensive therapy, the patient did not improve. On endoscopy, ulceration and inflammation were seen in the ileal pouch together with contact bleeding and mucous discharge. The patient was treated with rebamipide enema （150 rag/close） twice a clay for 8 wk without additional drug therapy. Two weeks after the rebamipide therapy, stool frequency started to decrease and fecal hemoglobin became negative at the 4^th wk. At the end of the therapy, endoscopy revealed that ulcers in the ileal pouch had healed with no obvious inflammation. The effect of rebamipide enema was dramatic and was maintained throughout the ll-mo follow-up. The patient continued to be in remission. No adverse effects were observed during the treatment or the follow-up period. The sustained response seen in this case with severe and refractory pouchitis indicates that agents, which promote epithelial cell growth, angiogenesis and mucosal tissue regeneration, are potential therapeutic agents for the treatment of refractory colorectal lesions.

Erythropoietin -induced proliferation of gastric mucosal cells

AIM： To analyze the localization of erythropoietin receptor on gastric specimens and characterize the effects of erythropoietin on the normal gastric epithelial proliferation using a porcine gastric epithelial cell culture model. METHODS： Erythropoietin receptor was detected by RT-PCR, Western blotting and immunohistochermistry. Growth stimulation effects of erythropoietin on cultured gastric mucosal cells were determined by ELISA using bromodeoxyuridine （BrdU）. RESULTS： Erythropoietin receptor was detected on cultured porcine gastric mucosal epithelial cells. Erythropoietin receptor was also detected histochemically at the base of gastric mucosal epithelium. BrdU assay demonstrated a dose-dependent increase in growth potential of cultured porcine gastric mucosal epithelial cells by administration of erythropoietin, as well as these effects were inhibited by administration of antierythropoietin antibody （P〈 0.01）. CONCLUSION： These findings indicate that erythropoietin has a potential to proliferate gastric mucosal epithelium via erythropoietin receptor.

Interactions of primary neuroepithelial progenitor and brain endothelial cells: distinct effect on neural progenitor maintenance and differentiation by soluble factors and direct contact

Neurovascular interactions are crucial for the normal development of the central nervous system. To study such interactions in primary cultures, we developed a procedure to simultaneously isolate neural progenitor and endothelial cell fractions from embryonic mouse brains. Depending on the culture conditions endothelial cells were found to favor maintenance of the neuroprogenitor phenotype through the production of soluble factors, or to promote neuronal differentiation of neural progenitors through direct contact. These apparently opposing effects could reflect differential cellular interactions needed for the proper development of the brain.

Endothelial precursor cells promote angiogenesis in hepatocellular carcinoma

AIM:To investigate the role of bone marrow-derived endothelial progenitor cells(EPCs) in the angiogenesis of hepatocellular carcinoma(HCC).METHODS:The bone marrow of HCC mice was reconstructed by transplanting green fluorescent protein(GFP) + bone marrow cells.The concentration of circulating EPCs was determined by colony-forming assays and fluorescence-activated cell sorting.Serum and tissue levels of vascular endothelial growth factor(VEGF) and colony-stimulating factor(CSF) were quantified by enzyme-linked immunosorbent assay.The distribution of EPCs in tumor and tumor-free tissues was detected by immunohistochemistry and real-time polymerase chain reaction.The incorporation of EPCs into hepatic vessels was examined by immunofluorescence and immunohistochemistry.The proportion of EPCs in vessels was then calculated.RESULTS:The HCC model was successful established.The flow cytometry analysis showed the mean percentage of CD133CD34 and CD133VEGFR2 double positive cells in HCC mice was 0.45% ± 0.16% and 0.20% ± 0.09% respectively.These values are much higher than in the sham-operation group(0.11% ± 0.13%,0.05% ± 0.11%,n = 9) at 14 d after modeling.At 21 d,the mean percentage of circulating CD133CD34 and CD133VEGFR2 cells is 0.23% ± 0.19%,0.25% ± 0.15% in HCC model vs 0.05% ± 0.04%,0.12% ± 0.11% in control.Compared to the transient increase observed in controls,the higher level of circulating EPCs were induced by HCC.In addition,the level of serum VEGF and CSF increased gradually in HCC,reaching its peak 14 d after modeling,then slowly decreased.Consecutive sections stained for the CD133 and CD34 antigens showed that the CD133+ and CD34+ VEGFR2 cells were mostly recruited to HCC tissue and concentrated in tumor microvessels.Under fluorescence microscopy,the bone-marrow(BM)-derived cells labeled with GFP were concentrated in the same area.The relative levels of CD133 and CD34 gene expression were elevated in tumors,around 5.0 and 3.8 times that of the tumor free area.In frozen liver sections from HCC mice,cells co-expressing CD133 and VEGFR2 were identified by immunohistochemical staining using anti-CD133 and VEGFR2 antibodies.In tumor tissue,the double-positive cells were incorporated into vessel walls.In immunofluorescent staining.These CD31 and GFP double positive cells are direct evidence that tumor vascular endothelial cells(VECs) come partly from BM-derived EPCs.The proportion of GFP CD31 double positive VECs(out of all VECs) on day 21 was around 35.3% ± 21.2%.This is much higher than the value recorded on day 7 group(17.1% ± 8.9%).The expression of intercellular adhesion molecule 1,vascular adhesion molecule 1,and VEGF was higher in tumor areas than in tumor-free tissues.CONCLUSION:Mobilized EPCs were found to participate in tumor vasculogenesis of HCC.Inhibiting EPC mobilization or recruitment to tumor tissue may be an efficient strategy for treating HCC.

Expression and clinical implication of p27 and p57 in cutaneous squamous cell carcinoma and Bowen's disease

Objective： To investigate the expression and clinical significance of cyclin dependent kinase inhibitors p27 and p57 in cutaneous squamous cell carcinoma and Bowen＇s disease. Methods： The expression of p27 and p57 were evaluated in 10 normal skin tissues, 25 Bowen＇s disease （BD） and 30 cutaneous squamous cell carcinoma （SCC） with immunohistochemistrical staining. Results： The levels of p27 protein expression in SCC were dramatically lower than those in normal skin and BD （P 〈 0.057. The levels of p57 protein expression in SCC were dramatically lower than those in normal skin and BD （P 〈 0.057. There was a posilk, e correlation between p27 and p57 （r = 0.469, P 〈 0.057. Conclusion： The decrease of p27 and skp2 may be used for considering the biological behavior of human cutaneous squamous cell carcinoma and Bowen＇s disease.

Aggressive primary hepatic epithelioid hemangioendothelioma:a case report and literature review

A new case of epithelioid hemangioendothelioma is reported to have occurred to a 67-year-old patient who consulted for rightsided chest pain. The work-up showed multiple right pulmonary lesions associated with bilateral moderate pleural effusion and left-sided pleural thickening and three hypodense nodules in the right lobe of the liver, peritoneal thickening, ascites, and multiple vertebral lytic lesions. The diagnosis of an epithelioid hemangioendothelioma was concluded through a histological examination of a computed tomography scan guided biopsy of the liver. The patient received a primary mono-chemotherapy with Adriamycin(75 mg/m^2 every three weeks) and intravenous bisphosphonates without response and general status impairment. The patient died after 16 months of follow-up.

Ex vivo differentiation of multipotent adult progenitor cells to skin epidermal cells

Objective： By establishing the indirect contact co-culture system, we studied the in vitro condition for MAPCs differentiating into epidermal cells and the transformation of MAPCs into epidermal cell phenotype. Methods： Cell culture insert membrane was used for substitute basal membrane and MAPCs, fibroblast cells （FCs） and mixture of MAPCs and epidermal cells and FCs were separately implanted into 2 sides of it. PKH26 was used to label cloned MAPCs; type IV collagen rapid adhering method was used to isolate and culture the skin epidermal cells from l-day-old SD rat. Results： Part of the MAPCs transformed into cells expressing keratin in the presence of peripheral epithelia and FCs. Type Ⅳ collagen rapid adhering method successfully selected rats＇ epidermal stem cells. The mixture of the 2 kinds of cells or indirect culture might promote the differentiation through mesenchymal factors secreted by dermis FC. Conclusion： We were the first to have established the in vitro model of MAPCs differentiation into epidermal cells, in which MAPCs were transformed into epithelium-like cells.

Ephrin-B2 is differentially expressed in the intestinal epithelium in Crohn's disease and contributes to accelerated epithelial wound healing in vitro

AIM:Eph receptor tyrosine kinases and their membrane bound receptor-like ligands, the ephrins, represent a bi-directional cell-cell contact signaling system that directs epithelial movements in development. The meaning of this system in the adult human gut is unknown. We investigated the Eph/ephrin mRNA expression in the intestinal epithelium of healthy controls and patients with inflammatory bowel disease (IBD). METHODS: mRNA expression profiles of all Eph/ephrin family members in normal small intestine and colon were established by real-time RT-PCR. In addition, differential expression in IBD was investigated by cDNA array technology, and validated by both real-time RT-PCR and immunohistochemistry. Potential effects of enhanced EphB/ephrin-B signaling were analyzed in an in vitro IEC-6 cell scratch wound model. RESULTS: Human adult intestinal mucosa exhibits a complex pattern of Eph receptors and ephrins. Beside the known prominent co-expression of EphA2 and ephrinAl, we found abundantly co-expressed EphB2 and ephrin-B1/2. Interestingly, cDNA array data, validated by real-time PCR and immunohistochemistry, showed upregulation of ephrin-B2 in both perilesional and lesional intestinal epithelial cells of IBD patients, suggesting a role in epithelial homeostasis. Stimulation of ephrin-B signaling in ephrin- B1/2 expressing rat IEC-6-cells with recombinant EphB1-Fc resulted in a significant dose-dependent acceleration of wound closure. Furthermore, fluorescence microscopy showed that EphB1-Fc induced coordinated migration of wound edge cells is associated with enhanced formation of lamellipodial protrusions into the wound, increased actin stress fiber assembly and production of laminin at the wound edge. CONCLUSION: EphB/ephrin-B signaling might represent a novel protective mechanism that promotes intestinal epithelial wound healing, with potential impact on epithelial restitution in IBD.

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM:To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in livertransplanted rats. METHODS:Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups:a shamoperation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion. RESULTS:With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened. CONCLUSION:A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.