Intrahepatic Bile Duct System Research Articles

Intrahepatic distribution of nerves in Suncus murinus by whole-mount immunohistological observation.

In recent years, elucidating the actual state of the liver nervous system has attracted attention, owing to clinical needs, such as liver transplantation. Conventional methods for studying the intrahepatic nerve distribution mostly use liver tissue sections, specific markers for immunohistological studies, or anterograde/retrograde tracing in animals. However, knowledge of the three-dimensional structure of intrahepatic innervation is vague or speculative. In this study, Suncus murinus (Suncus) (n = 10) were perfused and fixed, the livers were excised, and the liver parenchyma was carefully removed, leaving only the intrahepatic vasculature. Specimens were prepared to study the three-dimensional structure of Suncus intrahepatic and hilar innervation by whole-mount immunohistochemical staining using a neurofilament protein antibody. After the nerves running along the intrahepatic arterial system entered the liver parenchyma from the hepatic hilum, they maintained a relatively rich distribution along the interlobular arteries until the distal end. The innervation of the portal system began to decrease after entering the liver parenchyma and decreased significantly after reaching the deep parts. By the time it reached the end of the interlobular vein, there was very little left. The number of nerves running along the intrahepatic bile duct system was significantly reduced after entering the porta hepatis, and innervation was difficult to observe after completely entering the liver parenchyma. Whole-mount immunohistochemical analyses with an anti-NFP antibody showed that intrahepatic innervation mainly accompanied the hepatic interlobular arteries and extended to their terminal ends. Neuronal regulation is very important in the functional regulation of intrahepatic nutritional vessels. However, there were very few NFP-immunoreactive nerves accompanying the intrahepatic bile duct system, possibly suggesting that the functional regulation of the intrahepatic biliary system mainly relies on hormones and neuropeptides.

Gastrointestinal endoscopy in the diagnosis and treatment of biliary liver disease

Biliary liver disease refers to intrahepatic and extrahepatic bile duct system lesions or bile duct epithelial cells damage, resulting in abnormal liver function, inflammation and fibrosis, which mainly manifests as chronic cholestatic liver disease. The common causes include primary biliary cholangitis, primary sclerosing cholangitis, progressive familial intrahepatic cholangitis, bile duct complications after liver transplantation, and vanishing bile duct syndrome caused by drugs or serious infections, and the most prominent symptoms affecting the patients quality life is pruritus and jaundice. Endoscopic retrograde duodenoscopic cholangiopancreatography and cholangiopancreatoscopy (SpyGlass) and other endoscopic examinations can significantly improve the accuracy of early differential diagnosis,cytology and biopsy of primary sclerosing cholangitis, immunoglobulin G4-related cholangitis and cholangiocarcinoma. Endoscopic nasobiliary drainage, balloon dilatation and intrabiliary stent implantation can significantly improve pruritus symptoms, liver biochemical indicators and prognosis. Therefore, gastrointestinal endoscopy has important value and application prospects in the diagnosis and treatment of biliary liver diseases.

Cholangiogenic potential of human deciduous pulp stem cell-converted hepatocyte-like cells

BackgroundStem cells from human exfoliated deciduous teeth (SHED) have been reported to show the in vivo and in vitro hepatic differentiation, SHED-Heps; however, the cholangiogenic potency of SHED-Heps remains unclear. Here, we hypothesized that SHED-Heps contribute to the regeneration of intrahepatic bile duct system in chronic fibrotic liver.MethodsSHED were induced into SHED-Heps under cytokine stimulation. SHED-Heps were intrasplenically transplanted into chronically CCl4-treated liver fibrosis model mice, followed by the analysis of donor integration and hepatobiliary metabolism in vivo. Immunohistochemical assay was examined for the regeneration of intrahepatic bile duct system in the recipient liver. Furthermore, SHED-Heps were induced under the stimulation of tumor necrosis factor alpha (TNFA).ResultsThe intrasplenic transplantation of SHED-Heps into CCl4-treated mice showed that donor SHED-Heps behaved as human hepatocyte paraffin 1- and human albumin-expressing hepatocyte-like cells in situ and ameliorated CCl4-induced liver fibrosis. Of interest, the integrated SHED-Heps not only expressed biliary canaliculi ATP-binding cassette transporters including ABCB1, ABCB11, and ABCC2, but also recruited human keratin 19- (KRT19-) and KRT17-positive cells, which are considered donor-derived cholangiocytes, regenerating the intrahepatic bile duct system in the recipient liver. Furthermore, the stimulation of TNFA induced SHED-Heps into KRT7- and SRY-box 9-positive cells.ConclusionsCollectively, our findings demonstrate that infused SHED-Heps showed cholangiogenic ability under the stimulation of TNFA in CCl4-damaged livers, resulting in the regeneration of biliary canaliculi and interlobular bile ducts in chronic fibrotic liver. Thus, the present findings suggest that SHED-Heps may be a novel source for the treatment of cholangiopathy.

Application of 3D visualization and 3D printing in individualized precision surgery for Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma

To explore the application of 3D visualization and 3D printing in individualized precision surgical treatment of Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma. We retrospectively analyzed the data of 10 patients with hilar cholangiocarcinoma undergoing surgeries under the guidance of 3D visualization and 3D printing in the Department of Hepatobiliary Surgery, Zhujiang Hospital from May 2016 to March 2019. Thin-section CT data of the patients were collected for 3D reconstruction and 3D printing, and the 3D printed models were used for observing the 3D relationship of tumor with the intrahepatic bile duct, hepatic artery, portal vein and hepatic vein system and for performing preoperative simulated surgery and surgical planning. The 3D printed models were subsequently used for real-time intraoperative navigation to guide surgeries in the operating room. 3D visualization models were successfully reconstructed for all the 10 patients and printed into 3D models. The 3D visualization types in Bismuth-Corlette classification included type Ⅲa (4 cases), type Ⅲb (4 cases), and type Ⅳ (2 cases); 4 patients showed portal vein variation, 3 had hepatic artery variation, and 2 had both portal vein and hepatic artery variations. Two patients were found to have trifurcation type of portal vein variation, one had "I-shaped" variation, and one showed the absence of the right anterior branch of the portal vein; 3 patients had hepatic artery variations with the left hepatic artery originating from the left gastric artery (1 case) and the right hepatic artery originating from the superior mesenteric artery (2 cases). Four patients with type Ⅲb underwent left hepatectomy; 4 with type Ⅲa received right hepatectomy; 1 patient with of type Ⅳ received peripheral hepatic resection and another underwent left hepatectomy. The results of preoperative 3D reconstruction, 3D printed model and preoperative planning were consistent with the intraoperative findings. The operative time was 452±75.12 min with a mean intraoperative blood loss of 356±62.35 mL and a mean hospital stay of 15 ± 4.61 days in these cases. One patient had bile leakage and 3 patients had pleural effusion postoperatively, and they were discharged after drainage and medications. No liver failure or death occurred in these cases perioperatively. 3D visualization and 3D printing can facilitate accurate preoperative assessment, surgical planning and surgical procedure optimization for Bismuth-Corlette type Ⅲ and Ⅳ hilar cholangiocarcinoma to improve surgical safety and reduce surgical risks especially in cases of intrahepatic vascular variations.

Utility of a routine bench cholangiogram for ex situ split liver procedure.

Biliary complications can result in a significant morbidity for split liver graft recipients. Biliary drainage for segment 1 and 4 is highly variable and could be the source of bile leaks. Use of a bench cholangiogram (BCH) can accurately define the segmental biliary system and identify any significant biliary radicles that need retention or repair during bench preparation of split grafts. This study evaluates the clinical relevance of routine BCH in split liver transplantation (SLT). Retrospective review of 100 BCH images performed during ex situ deceased donor SLT between January 2009 and January 2015. The radiographs were reviewed by two surgeons and the biliary anatomy was compared using Huang and Reichert classification. 100 BCH images were reviewed. Variant anatomy was frequently identified in the intrahepatic bile duct system, the number and drainage patterns of segment 1&4 duct was diverse. BCH results guided the line of parenchymal transection to obtain a single segment 2&3 duct in 15 cases. A surgical intervention in the form of suture ligation of significant segment 1 or 4 duct at bench preparation was performed in 6 cases. BCH images guided surgical control of post-operative bile leak in 3 patients. Bench cholangiogram is a useful tool to guide liver parenchymal transection and potentially reduce the incidence of biliary complications.

Molecular regulation of mammalian hepatic architecture.

The essential liver exocrine and endocrine functions require a precise spatial arrangement of the hepatic lobule consisting of the central vein, portal vein, hepatic artery, intrahepatic bile duct system, and hepatocyte zonation. This allows blood to be carried through the liver parenchyma sampled by all hepatocytes and bile produced by the hepatocytes to be carried out of the liver through the intrahepatic bile duct system composed of cholangiocytes. The molecular orchestration of multiple signaling pathways and epigenetic factors is required to set up lineage restriction of the bipotential hepatoblast progenitor into the hepatocyte and cholangiocyte cell lineages, and to further refine cell fate heterogeneity within each cell lineage reflected in the functional heterogeneity of hepatocytes and cholangiocytes. In addition to the complex molecular regulation, there is a complicated morphogenetic choreography observed in building the refined hepatic epithelial architecture. Given the multifaceted molecular and cellular regulation, it is not surprising that impairment of any of these processes can result in acute and chronic hepatobiliary diseases. To enlighten the development of potential molecular and cellular targets for therapeutic options, an understanding of how the intricate hepatic molecular and cellular interactions are regulated is imperative. Here, we review the signaling pathways and epigenetic factors regulating hepatic cell lineages, fates, and epithelial architecture.

3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

3-Dimensional Resin Casting and Imaging of Mouse Portal Vein or Intrahepatic Bile Duct System

In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks. A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure(1,2), alterations in brain vasculature of a Alzheimer's disease mouse model(3), portal vein abnormalities in portal hypertensive and cirrhotic mice(4), developmental steps in rat lymphatic maturation between immature and adult lungs(5), immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury(6). Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network, focusing specifically on the portal vein and intrahepatic bile duct. These casts can be visualized by clearing or macerating the tissue and can then be analyzed. This technique can be applied to virtually any vascular or ductal system and would be directly applicable to any study inquiring into the development, function, maintenance, or injury of a 3-dimensional ductal or vascular structure.

Abdominal obesity, weight gain during adulthood and risk of liver and biliary tract cancer in a European cohort

General obesity has been positively associated with risk of liver and probably with biliary tract cancer, but little is known about abdominal obesity or weight gain during adulthood. We used multivariable Cox proportional hazard models to investigate associations between weight, body mass index, waist and hip circumference, waist-to-hip and waist-to-height ratio (WHtR), weight change during adulthood and risk of hepatocellular carcinoma (HCC), intrahepatic (IBDC) and extrahepatic bile duct system cancer [EBDSC including gallbladder cancer (GBC)] among 359,525 men and women in the European Prospective Investigation into Cancer and Nutrition study. Hepatitis B and C virus status was measured in a nested case-control subset. During a mean follow-up of 8.6 years, 177 cases of HCC, 58 cases of IBDC and 210 cases of EBDSC, including 76 cases of GBC, occurred. All anthropometric measures were positively associated with risk of HCC and GBC. WHtR showed the strongest association with HCC [relative risk (RR) comparing extreme tertiles 3.51, 95% confidence interval (95% CI): 2.09-5.87; p(trend) < 0.0001] and with GBC (RR: 1.56, 95% CI: 1.12-2.16 for an increment of one unit in WHtR). Weight gain during adulthood was also positively associated with HCC when comparing extreme tertiles (RR: 2.48, 95% CI: 1.49-4.13; <0.001). No statistically significant association was observed between obesity and risk of IBDC and EBDSC. Our results provide evidence of an association between obesity, particularly abdominal obesity, and risk of HCC and GBC. Our findings support public health recommendations to reduce the prevalence of obesity and weight gain in adulthood for HCC and GBC prevention in Western populations.

Right/left symmetry of the intrahepatic distribution and terminology of the hepatic artery proper and the intrahepatic bile duct system: proposals to revise the Terminologia Anatomica

Anatomical terminology is the foundation of medical terminology and it is important that doctors and scientists throughout the world use the same name for each structure. It is also important that the anatomical terms for a specific anatomical structure are presented in a logical order. To eliminate confusion, it is crucial that the same name is not attributed to two or more anatomical elements. However, the term artery of caudate lobe is used for two distinct anatomic elements with different origins (right/left branch of hepatic proper artery). Also, I draw attention to the incorrect positioning of right/left duct of caudate lobe in the description of terms homologated for the intrahepatic bile duct system. These proposals to amend the terminology in the liver anatomy are a necessary step in the evolution of the Terminologia Anatomica.

Bile duct to portal space ratio and ductal plate remnants in liver disease of infants aged less than 1 year

To validate the bile duct to portal space ratio as an independent factor useful for the prognosis of neonatal liver disease. We assessed the maturation of the intrahepatic bile duct system (IBDS) in 87 consecutive infants aged less than 1 year undergoing non-subcapsular, adequate (at least six portal tracts), liver needle biopsies because of hepatomegaly and/or cholestasis. The maturation of the IBDS was evaluated by immunohistochemistry with an antibody directed to cytokeratin 7 (CK7), a biliary-type intermediate filament of the cytoskeleton, and a schema showing the IBDS remodelling. We used five categories to fit the different patterns of the IBDS remodelling using the ratio between the number of bile ducts and the number of portal tracts (BD/PT) and the presence of abnormal reaction patterns (marked intra-acinar pseudorosettes and/or periportal ductular proliferation): (A) abnormal reaction patterns with any BD/PT; (B) BD/PT = 0; (C) 0.1 < or = BD/PT < 0.5; (D) 0.5 < or = BD/PT < 0.9; and (E) BD/PT > 0.9 (B-E categories: no abnormal reaction patterns). Further, we evaluated cholestasis, portal fibrosis (PF), portal inflammation (PI), giant cell transformation (GCT), and extramedullary haematopoiesis (EMH). We identified A-E categories in 24, 14, 17, 8, and 24 biopsies, respectively. B and C categories were frequently observed in biliary atresia (BA), A category in neonatal hepatitis (NH), A-C categories in paucity of intrahepatic bile ducts (PIBD), and E category in 'other liver diseases' (OLD). Cholestasis, PI, GCT, and EMH were more frequent in A and C, while PF was variably seen in all categories. The lowest survival rate occurred in B (Kaplan-Meier estimator). (1) Biliary epithelial cell patterns recapitulate the primitive stages of the IBDS maturation; (2) abnormal reaction patterns occur mainly in NH, whilst BD/PT < 0.5 in BA; and (3) lack of intrahepatic bile ducts in infants aged less than 1 year is an adverse prognostic factor independent from aetiology of neonatal liver disease.

Placement of a biliary metal stent to expand a choledochus stenosis after Frey's surgery

A 47-year-old patient presented with jaundice. Laboratory examinations confirmed cholestasis. The patient had a long history of chronic pancreatitis. Subsequently, cholecystectomy and a duodenumpreserving resection of the pancreatic head (Frey's surgery) had been performed. Endoscopic retrograd holangiography was done. The endoscope was inserted the normal way to the untouched papilla vateri. After injection of contrast medium, only the side-to-side choledocho-jejunal anastomosis but not the common bile duct could be visualized because the catheter spontaneously slipped into the jejunum via the side-to-side choledocho-jejunal anastomosis. After introducing a catheter percutaneously into the intrahepatic bile duct system, a long stenosis of the common bile duct could be visualized. It was possible to overcome the stenosis with a wire, but the wire also dislocated into the jejunum via the side-to-side choledocho-jejunal anastomosis and could not be placed through the papilla into the duodenum. The problem was solved in a tricky way: A wire was introduced into the common bile duct via the papilla and placed into the duodenum. A loop was brought in percutaneously and was also placed in the jejunum. With the loop, the wire was grabbed and taken out percutaneously. Now a biliary metal stent could be positioned correctly over the wire to expand the stenosis. After the procedure jaundice was cured quickly. The further course was uneventful with complete recovery.

ERCP characteristics of 164 patients of hepatocellular carcinoma with obstructive jaundice

AIM: To study the etiology and the manifestation of ERCP in patients of obstructive jaundice with HCC. METHODS: Routine ERCP examinations were performed in 164 cases of hepatocellular carcinoma complicated with obstructive jaundice. Intrahepatic bile duct system was filled as much as possible. Biliary drainage and antibiotics were given routinely after the procedures. RESULTS: Overall, 97.5 % presented as malignant bile duct obstruction and 2.4 % was benign biliary tract lesion. Among malignant obstruction, malignant hepatic hilar and perihilar bile duct stricture were found in 67.7 %, intraductal tumor thrombus in 20.1 %, intraductal thrombus with malignant perihilar stricture in 7.3 %, metastasis of hilar lymph nodes in 1.8 %, retroperitoneal lymph node metastasis in 1.2 %. While in benign lesions, choledolithiasis and distal common bile duct stenosis were found in 1.2 %, respectively. In 110 cases presented as malignant perihilar stricture, 95.4 % were diagnosed as type III and IV. In 33 cases of ductal thrombi, 90.9 % were classified as type III and IV. In 6 cases who were performed papillatomy to remove tumour thrombi, histopathologically, one was diagnosed possibly tumour, one of debris stone and necrotic tissues respectively, two of necrotic tumor tissues and 1 of HCC respectively. Two cases of bile duct cytology were shown exfoliated epithelial cells.

Induction of bile ducts in embryonic liver by mesenchyme: a new perspective for the treatment of biliary atresia?

Presently only those forms of Extrahepatic Biliary Atresia (EHBA) with minimal or no intrahepatic manifestations can be treated successfully by extensive hepatoportoenterostomy. Intraoperative macro- and microscopic observations show that the typical pathogenetic manifestations in EHBA are most prominent at the porta hepatis. We therefore postulate that EHBA is the result of a defective embryonic development of the porta hepatis. In rat embryos hepatic bile duct formation is initiated at the porta hepatis and in this context mesenchyme from the periportal region seems to play a major inductive role. In order to demonstrate the role of invading periportal mesenchyme for the process of bile duct rudiment formation we established an organ culture model of the embryonic porta hepatis by recombining periportal mesenchyme with peripheral liver fragments from 15 days old rat embryos (Carnegie Stage 21). The degree of mesenchyme invasion as well as the formation of mesenchyme-surrounded liver cell clusters, rosettes or vesicles (bile duct rudiments) were assessed. Mesenchyme from the porta hepatis invaded the peripheral liver fragments and induced the formation of mesenchyme-surrounded liver cell clusters and rosettes with the beginning of lumen formation. Kidney mesenchyme recombined with liver fragments as a mesenchymal alternative showed almost the same effect, lung mesenchyme showed only a very weak inductive effect. To assess the effect of a diffusible factor versus direct cell contact, a millipore filter with and without paraffin coating was interposed between mesenchyme containing tissue and peripheral liver tissue fragments. Without direct cell contact to mesenchyme no hepatoblast cluster or rosette formation could be observed. Comparing this result to the normal development of the liver in rats our investigations suggest that the embryogenesis of the porta hepatis is probably defined by the following two developmental steps: First, differentiation of the intrahepatic bile duct system which is induced by invading mesenchyme originating from the extrahepatic periportal region and realized by epithelium mesenchyme interaction. Second, fusion of extra- and intrahepatic bile duct systems at the level of the later porta hepatis. Disturbances of this complex process can possibly lead to biliary atresia. Further investigations regarding details of the role of the mesenchyme, its inductive factors and the kidney mesenchyme's inductive potential in liver development may provide a new perspective for future treatment of biliary atresia.

Distortion in TGF beta 1 peptide immunolocalization in biliary atresia: comparison with the normal pattern in the developing human intrahepatic bile duct system.

Biliary atresia is an important cause of neonatal obstructive jaundice in which there is inflammation, sclerosis and eventual obliteration of the bile duct system. Its onset may be antenatal, affecting the normal development of the biliary system. The intrahepatic biliary system is derived from the ductal plate, a sheath of cuboidal epithelium that appears at the hepatocyte-mesenchymal junction around the portal vein branches at 6 weeks gestation. This epithelial structure is moulded into a network of tubular bile ducts by the proliferating mesenchyme. Certain portions of the ductal plate are selected to become definitive bile ducts, while redundant biliary epithelium is deleted. The molecular dynamics controlling the intra-uterine development of the biliary system in humans are not yet clearly understood. Transforming growth factor-beta 1 is a cytokine that stimulates mesenchymal proliferation and inhibits epithelial growth, and has been shown to be important in organogenesis. In the present study, the pattern of TGF beta 1 peptide immunolocalization was investigated with the aid of computerized image analysis, in normal human bile duct development and in biliary atresia. TGF beta 1 peptide was detected within hepatocytes and ductal plate epithelium from 7 weeks gestation; increased TGF beta 1 immunoreactivity was present within the epithelium of developing bile ducts at 13 weeks gestation, and apical polarization of the cytokine was observed from 16 weeks gestation. In biliary atresia, the TGF beta 1 immunoreactivity pattern within the bile duct structures at the porta hepatis and within intrahepatic portal tracts resembled that of the primitive ductal plate, and there was no significant apical polarization. This may indicate a developmental arrest in the normal ductal plate remodelling process in biliary atresia, and suggests an underlying epithelial-mesenchymal interactive disorder.

Biliary tract strictures after orthotopic liver transplantation: diagnosis and management.

Biliary tract complications in 105 patients who had undergone orthotopic liver transplantation were reviewed in order to determine their incidence and localization. In addition, the possible endoscopic and percutaneous management of such complications was evaluated. Signs of cholestasis appeared in 32 of 105 (30.5%) transplant recipients after a mean of 6.5 months (range 1-19 months), and visualization of the biliary system was performed in all. Twenty biliary tract complications were observed in these 32 patients (62.5%). There were multiple strictures, both intrahepatic and extrahepatic, in 11 grafts. Five of the nine extrahepatic strictures were not confined to the site of the bile duct anastomosis, and involved the whole common bile duct of the donor liver, while the remaining four were confined. The multiple intrahepatic and extrahepatic strictures were related either to occlusion of the hepatic artery or to the fact that the graft had been in a cold ischemic state for a prolonged time. In contrast, multiple strictures and necrosis of the whole extrahepatic bile duct were attributed to local ischemia due to the harvesting procedure. Stenoses strictly confined to the site of anastomosis were thought to be due to surgical technique. Ten extrahepatic bile duct stenoses with considerably impaired bile flow were corrected endoscopically (four), percutaneously (three) and by surgery (three). In four patients with complications in the whole intrahepatic and extrahepatic system, retransplantation was necessary. Biliary tract complications in our patients occurred in up to 19% after liver transplantation on long-term follow-up. Complications of only the extrahepatic system can be treated successfully, whereas complications involving multiple stenoses of the intrahepatic bile duct system frequently require retransplantation.

The development of the intrahepatic bile ducts in man: A keratin-immunohistochemical study

The development of the intrahepatic bile ducts in man was studied using an immunohistochemical technique on 56 liver specimens ranging in age from 6 weeks of gestation to 8 months after birth. On paraffin sections, two monoclonal anticytokeratin antibodies (CAM 5.2 and KL-1) that normally stain both hepatocytes and bile duct cells and two polyclonal anticytokeratin antisera that in normal adult liver stain bile ducts only were applied. For immunohistochemical staining of cryostat sections (only available from 14 weeks of gestation on), four monoclonal antibodies specifically directed against individual cytokeratin polypeptides 7,8, 18 and 19 were used. Adult human hepatocytes contain cytokeratin 8 and 18 whereas bile duct cells also express cytokeratin 7 and 19 in addition to cytokeratin 8 and 18. On paraffin sections, primitive hepatocytes were stained with monoclonal antibodies CAM 5.2 and KL-1 from 6 weeks of gestation on. On cryostat sections, they were positive with monoclonal antibodies anticytokeratin 8 and 18 from the earliest time point examined (14 weeks). From 9 weeks of gestation on, portal vein branches were surrounded by a layer of cells showing a stronger positive reaction with monoclonal antibodies CAM 5.2 and KL-1 on paraffin sections and with monoclonal antibodies anti-cytokeratin 8 and 18 on cryostat sections (only available from 14 weeks on). This layer, referred to as the ductal plate, first appeared around large portal vein branches close to the hilum and subsequently around more peripheral branches. The duct plates became duplicated over variably long segments of their perimeter, lumina appeared and tubular structures were formed. The latter gradually became incorporated in the connective tissue surrounding the portal vein, resulting in the appearance of individualized bile ducts. Ductal plate cells were stained by both polyclonal anticytokeratin antisera on paraffin sections. On cryostat sections (available from 14 weeks of gestation on), they were immunoreactive for cytokeratin 19 but negative with the monoclonal antibody directed against cytokeratin 7 until 20 weeks of gestation. From then on, weakly positive staining for cytokeratin 7 was detected, but staining intensity subsequently increased and reached the level observed in adult liver at 1 month after birth. At birth, the smallest branches of the portal vein were still surrounded by a discontinuous ductal plate. We conclude that intrahepatic bile duct cells develop from hepatocytes around branches of the portal vein.(ABSTRACT TRUNCATED AT 400 WORDS)

Endoscopic retrograde intrahepatic cholangiography in liver diseases

Particular attention to the radiographic characteristics of the intrahepatic bile duct system was directed to a series of 56 patients selected on the basis of having nearly simultaneous endoscopic retrograde cholangiography and liver biopsy. Careful attention to details of the fine ductal configuration may contribute information helpful in resolving the differential diagnosis of intrahepatic disease.

A CASE OF ABNORMAL INTRAHEPATIC BILE DUCT ARRANGEMENT SUBMITTED TO THREE DIMENSIONAL RECONSTRUCTION

A case of abnormal intrahepatic bile duct arrangement, which in all probability should be classified as congenital hepatic fibrosis, was submitted to three‐dimensional reconstruction. This proved that the duct system of the portal tracts had the form of curving plates. This unusual architecture is compared with the embryological development of the intrahepatic bile duct system. On this base a hypothesis of the pathogenesis of the abnormal findings is presented.

Intrahepatic biliary obstruction in congenital bile duct atresia.

The three-dimensional structure of small intrahepatic bile ducts in congenital biliary atresia was examined by graphical reconstruction of serial histological sections. In the disease, intrahepatic bile duct system was constituted by an extremely complex network of proliferating bile ductules. Bile duct proliferation was interpreted as a reaction of the bile system to bile stagnation and bile leakage in the portal area. The restoration of a patent intrahepatic bile system seemed to depend upon the preservation of `main routes' of bile passage, which probably belonged to the pre-existing bile duct system. The maintenance of anatomically recognizable main routes could be correlated with the clinical effect of extrahepatic bile duct plasty.