Extramural Glands Research Articles

Heterogeneous murine peribiliary glands orchestrate compartmentalized epithelial renewal

The extrahepatic branches of the biliary tree have glands that connect to the surface epithelium through narrow pits. The duct epithelia undergo homeostatic renewal, yet the identity and multiplicity of cells that maintain this tissue is unknown. Using marker-free and targeted clonal fate mapping in mice, we provide evidence that the extrahepatic bile duct is compartmentalized. Pit cholangiocytes of extramural glands renewed the surface epithelium, whereas basally oriented cholangiocytes maintained the gland itself. In contrast, basally positioned cholangiocytes replenished the surface epithelium in mural glands. Single-cell sequencing identified genes enriched in the base and surface epithelial populations, with trajectory analysis showing graded gene expression between these compartments. Epithelia were plastic, changing cellular identity upon fasting and refeeding. Gain of canonical Wnt signaling caused basal cell expansion, gastric chief cell marker expression, and a decrease in surface epithelial markers. Our results identify the cellular hierarchy governing extrahepatic biliary epithelial renewal.

ВОЗРАСТНЫЕ ИЗМЕНЕНИЯ ЗАСТЕННЫХ ЖЕЛЕЗ ПИЩЕВАРИТЕЛЬНОЙ СИСТЕМЫВ ПОСТЭМБРИОНАЛЬНОМ ПЕРИОДЕ У ОВЕЦ

This article shows the research findings on age-related changes in the extramural glands of the digestive system of sheep during the postembryonic stage of ontogenesis. The study identified the first month as the most critical period in the postnatal ontogenesis for the growth and development of extramural digestive glands, marked by the most intensive growth in relative organ masses (liver and pancreas of sheep from 12 to 15 months). Organ growth is sustained for 2-3 months, followed by a decline in the growth rate and maximum parenchymal development. Changes in the relative mass of the liver and its lobes occur non-uniformly in terms of the aging process. The relative mass values of the liver lobes increase most intensively up to the age of 12 months, after which they gradually decrease. The weight of the pancreas increased 14.84 times from the age of 3 days to 48 months. The most intensive linear growth occurs at the ages of 3 and 12 months of postnatal development, with the growth values of the right lobe exceeding those of the left lobe and the body of the gland. The histological structure of the liver and pancreas has a typical organization. The development processes of glandular epithelium in the extramural digestive glands occur unevenly and exhibit heterochrony, manifested in the establishment of their structural organization.

Pure Laparoscopic Left Hemihepatectomy for Hepatic Peribiliary Cysts with Biliary Intraepithelial Neoplasia.

Introduction. Hepatic peribiliary cysts (HPCs) usually originate due to the cystic dilatation of the intrahepatic extramural peribiliary glands. We describe our rare experience of pure laparoscopic left hemihepatectomy (PLLH) in a patient with HPCs accompanied by a component of biliary intraepithelial neoplasia (BilIN). Case Presentation. A 65-year-old man was referred for further investigation of mild hepatic dysfunction. Contrast-enhanced computed tomography showed dilatation of the left-sided intrahepatic bile duct, and biliary cytology showed class III cells. The patient was highly suspected of having left side-dominated cholangiocarcinoma and underwent PLLH. Microscopic findings revealed multiple cystic dilatations of the extramural peribiliary glands; hence, this lesion was diagnosed as HPCs. The resected intrahepatic bile duct showed that the normal ductal lumen comprised low columnar epithelia; however, front formation on the BilIN was observed in some parts of the intrahepatic bile duct, indicating that the BilIN coexisted with HPCs. Conclusion. We chose surgical therapy for this patient owing to the presence of some features of biliary malignancy. We employed noble PLLH as a minimally invasive procedure for this patient.

Osteopontin Expression in Patients with Hepatolith.

To investigate the role of osteopontin (OPN) in the formation of hepatolith, we have immunohistochemically studied the involvement of OPN in hepatolithiasis in the intrahepatic bile ducts and the intramural and extramural glands, and in stones. In our hospital, 17 hepatic resections for hepatolithiasis were carried out from June 2006 to October 2009. Immunohistochemistry was performed on 17 liver specimens with hepatolith and on 24 control liver specimens without hepatolith. We compared the osetopontin expression in the epithelia of the intrahepatic bile ducts and peribiliary glands or periglandular macrophages. Staining for OPN was positive in the cytoplasm of the epithelial cells of stone-containing intrahepatic bile ducts and the intramural and extramural glands, and in stones. But there were no significant differences between the hepatolithiasis group and the control group for the OPN immunoreactivity of the luminal surface of the epithelial cells of the intrahepatic bile ducts and intramural and extramural glands. The stone-containing intrahepatic bile ducts were infiltrated by macrophages that showed intense staining for OPN. The core and matrix of the stones showed OPN immunoreactivity. The degree of OPN from the cytoplasm of the epithelia of the intrahepatic bile ducts and peribiliary glands or periglandular macrophages was different between hepatolithiasis and control groups. Our result suggests that the OPN from the intrahepatic bile ducts and peribiliary glands plays a role in the formation of intrahepatic stone.

Sudden death due to polyarteritis nodosa

Classical polyarteritis nodosa (cPAN) refers to a rare, potentially fatal systemic transmural necrotizing vasculitis that usually affects medium-sized, and occasionally small, muscular arteries, primarily involves the kidneys, gastrointestinal tract, skin, nervous system, joints, and muscles, and is rarely, if ever, expressed in the lungs. The incidence of mortality has significantly decreased with recently developed treatment modalities, in particular antiviral medications. Sudden death due to previously undiagnosed cPAN is rarely encountered. We report a case of a young man who had been evaluated on three occasions by medical personnel in the 3 weeks prior to his death. He had complained of nonspecific symptoms of abdominal and perineal/suprapubic pain, nausea, vomiting, sensation of chilling, and constipation. The spectrum of diagnoses included "gastroenteritis," enteric infection, and prostatitis. Found agonal at home and dying despite immediate cardiopulmonary resuscitation (CPR), he underwent a medicolegal autopsy, which revealed vasculitis of various organs, including heart (myocardium and epicardium) and extramural coronary arteries, liver, spleen, kidneys, adrenal glands, stomach and bowel, omentum, gallbladder, and pancreas. His sudden death was cardiac in nature due to PAN associated clinically with hepatitis B surface antigen positivity (hepatitis B virus-associated PAN [HBV-PAN]). A complete autopsy with thorough histopathological examination is necessary to diagnose this uncommon yet potentially fatal vasculitis.

The role of peribiliary cysts in biliary obstruction

Peribiliary cysts are cystic dilatations of the extramural glands of the intrahepatic biliary tree. This disorder is uncommon and is usually asymptomatic. However, it may cause extrinsic biliary compression and consequently, obstructive jaundice. This paper describes 2 such cases presenting with jaundice. The etiology, natural history, investigation findings and treatment of this disorder are also discussed.

An immunohistochemical study of osteopontin in hepatolithiasis

Mucin glycoprotein from the intrahepatic bile ducts, and from the intramural and extramural glandular epithelia, is thought to contribute to the formation of the matrix, or nucleus, in hepatolithiasis and to contribute to biomineralization systems. Osteopontin (OPN), a noncollagenous acidic bone matrix glycoprotein that possesses calcium-binding properties. To investigate the role of OPN in the genesis of hepatolithiasis, OPN was immunohistochemically studied in the intrahepatic bile ducts, intramural and extramural glands, and in stones. An immunohistochemical study was performed in 21 human liver specimens with hepatolithiasis, by the EnVision (Dako Japan, Kyoto, Japan) method. Staining for OPN was strongly positive in the epithelium of stone-laden intrahepatic bile ducts, intramural and extramural glands, and in stones. The stone-laden intrahepatic bile ducts were infiltrated by macrophages showing intense staining for OPN. Sections of the hepatolithiasis, viewed under low magnification, showed a lamellar pattern of OPN immunolabeling, and they showed a reticular pattern under high magnification. In the center of the stones, large nestlike membranous structures were frequently present. Our result indicates that OPN, an acidic glycoprotein from intrahepatic bile ducts and from intramural and extramural glandular epithelia, seems to be involved in lithiasis, both as a core protein in the early phase, and in the late phase.

Proliferating cell nuclear antigen expression in peribiliary glands of stone-containing intrahepatic bile ducts.

All cases of hepatolithiasis showed features of chronic proliferative cholangitis, and it has been speculated that the atypical glandular proliferation might be a precursor to overt cholangiocarcinoma. Proliferative cell nuclear antigen (PCNA) is a nuclear protein synthesized in the G1/S phase of the cell cycle and therefore is related to cell proliferative activity. In an attempt to assess the activity of cell proliferation of stone-containing intrahepatic bile ducts, we conducted a study using immunohistochemical staining with monoclonal antibody to score PCNA in intrahepatic bile ducts. Thirty patients (10 men, 20 women; mean age 52.4 years) having hepatolithiasis surgically resected were studied. Ten stone-free patients served as controls. All 40 specimens were immunostained for PCNA using PC 10 monoclonal antibody. PCNA of both stone-containing and stone-free intrahepatic bile ducts were assessed by counting positive staining nuclei per 500 cells and expressed as labeling index (LI), ie, percentage of positive nuclei to the total number of nuclei. The PCNA LI in stone-free intrahepatic bile ducts was generally low: 10.0+/-13.2%, 10.4+/-10.7% and 7.9+/-9.6% for extramural glands, intramural glands, and epithelial lining, respectively. In contrast, the PCNA LI for stone-containing intrahepatic bile ducts were significantly higher than those of controls (P < 0.001): 49.4+/-8.3%, 40.6+/-7.0% and 34.1+/-6.8% for extramural glands, intramural glands, and epithelial lining, respectively. The extramural glands had a significantly higher PCNA LI (P < 0.001) than the intramural glands and controls. Hyperplasia was found in all specimens, while dysplasia was found in six of 30 cases with hepatolithiasis. The dysplastic cells also had a higher PCNA LI (P < 0.001) than the hyperplastic cells and normal epithelium. Our findings showed that there is marked increase of activity of cell proliferation in stone-containing intrahepatic bile ducts. It is well known that genetic mutations are facilitated in proliferating cells. Therefore, our results suggest that the high epithelial turnover in dysplastic cells and extramural glands had higher potential for proliferation and neoplastic transformation in long-standing untreated hepatolithiasis.

Microstructure and development of the normal and pathologic biliary tract in humans, including blood supply.

Microstructure and development of the normal biliary tract and the pathologies of several biliary tract diseases in humans are reviewed. The biliary tract, comprising the bile duct and peribiliary glands, is anatomically divided into the extrahepatic and intrahepatic biliary tree. The intrahepatic biliary tree is further divided into large bile ducts, corresponding to the right and left hepatic ducts and their first to third order branches, and into septal and interlobular bile ducts and bile ductules according to their size and location relative to the hepatic lobules and surrounding structures. The right and left hepatic ducts and the extrahepatic bile ducts are composed of dense fibrous duct walls lined by a layer of columnar biliary epithelium. The peribiliary glands, which may secrete mucinous and serous substances into the bile, are found along the extrahepatic and large intrahepatic bile ducts. They are divided in glands within and outside the duct wall. The former (intramural glands) drain directly into the lumen of the bile duct, while the latter (extramural glands) are composed of several lobules and drain into the ductal lumen via their own conduits. The biliary tract is supplied by a complex vasculature called the peribiliary vascular plexus. Afferent vessels of this plexus derive from hepatic arterial branches, and this plexus drains into the portal venous system or directly hepatic sinusoids. The development of the intrahepatic biliary tract is divided into three stages: the stage of the ductal plate, the stage of biliary cell migration into the mesenchyme, and the stage of bile duct formation in the portal tract. It remains unclear how the extrahepatic and intrahepatic biliary tract integrate. Along with these developmental changes in the biliary tract, the peribiliary glands and the vascular plexus also develop in a step-wise manner and their maturation is completed after birth. Pathologies of various biliary diseases are briefly reviewed noting their relevance to several histologic elements and the microenvironment of the biliary tract and the developmental anomalies of the biliary tract including ductal plate malformation.

Lectin histochemical study of cholagiocarcinoma arising from stone‐bearing intrahepatic bile duct

With the purpose of studying changes in the expression of glycoconjugate structures in cholangiocarcinoma and the nonneoplastic epithelium of stone-bearing intrahepatic bile ducts, a panel of 12 biotinylated lectins were used on formalin-fixed, paraffin-embedded tissue sections from 13 patients who had undergone surgical resection of cholangiocarcinoma and on nonneoplastic stone-bearing intrahepatic bile ducts from 10 patients. Of the 13 patients with cholangiocarcinoma 10 had hepatolithiasis and 3 did not. Among the 12 lectins, only wheat germ agglutinin (WGA) stained the cholangiocarcinoma and nonneoplastic epithelium of the stone-bearing intrahepatic bile duct. All nonneoplastic epithelia of stone-bearing intrahepatic bile ducts were stained heavily and homogeneously by WGA, the GlcNAC-specific lectin. The high columnar epithelium of both intramural and extramural glands was stained in the supranuclear region, while the low columnar epithelium of serous acini was stained in the whole cytoplasm. cytoplasm. In the well-differentiated cholangiocarcinoma, the WGA weakly stained the neoplastic cells in the supranuclear region, while it stained the luminal cytoplasmic membrane heavily. In the poorly-differentiated cholangiocarcinoma, about 50% of cancer cells were stained with WGA. The carcinoma was moderately stained in the cytoplasm. Less reactivity and a lower percentage of cells stained with lectin were found in cholangiocarcinomas when compared to nonneoplastic epithelia. This led us to conclude that there is a dramatic decrease in lectin-binding carbohydrate structures associated with cholangiocarcinoma progression.

A lectin histochemical study of intrahepatic ducts in patients with hepatolithiasis

A panel of 12 biotinylated lectins was used to investigate the diversity of glycoconjugate on the epithelium of stone-containing intrahepatic bile ducts and compared to controls. Among the 12 lectins, only WGA (wheat germ agglutinin) and Con A (concanavalin agglutinin) stained the epithelium of stone-containing intrahepatic ducts. Con A, a glucose/mannose-specific lectin, bound weakly on the epithelium of the stone-bearing intrahepatic duct in 10 of the 25 specimens, but none of the controls. All stone-containing intrahepatic bile ducts were stained heavily and homogenously by WGA, the N-acetylglucosamine-specific lectin. The high columnar epithelia of both intramural and extramural glands were stained in the supranuclear region, while the serous acini of extramural glands were stained in whole cytoplasm. The epithelium of intrahepatic ducts from the controls was stained weakly by WGA only. The WGA receptors were not abolished by pretreatment of neuraminidase. This led us to conclude that the stone-containing intrahepatic ducts were rich in N-acetylglucosamine and the heavy and homogenous staining with WGA will be indicative of hypersecretion of mucus from stone-bearing intrahepatic bile ducts.

Intrahepatic peribiliary glands of humans. I. Anatomy, development and presumed functions

The intrahepatic biliary tree is regarded as an excretory duct of two secretory units: hepatocytes and intrahepatic peribiliary glands. This review describes the anatomy, development and presumed functions of the latter. These glands are preferentially located around the intrahepatic large bile ducts, and are histologically divided into intramural and extramural structures. The former consist of simple tubular glands with much mucin, and are sparsely and irregularly distributed within the ductal wall. The latter are characterized by the presence of excretory units that consist of seromucinous acini and a conducting system in the periductal tissue. Pancreatic exocrine acini are occasionally admixed with extramural glands. These peribiliary glands appear in the late fetal period and complete their development about 15 years after birth. Extramural and intramural glands secrete neutral and acid mucin into the ductal lumen. Extramural glands contain several enzymes for digestion of protein and lipids. Neural and vascular supply of these glands may be related to the regulation of their secretion. Specific and non-specific immune responses within this glandular system may also be essential in the sterility of bile.

Lactoferrin and lysozyme in the intrahepatic bile duct of normal livers and hepatolithiasis: An immunohistochemical study

Lactoferrin and lysozyme have bactericidal activities and are responsible for mucosal defense against local bacterial infections. To assess the local defense mechanisms in the intrahepatic biliary tree, we studied the distribution of lactoferrin and lysozyme immunohistochemically in 14 normal autopsy livers and in 29 surgically resected and two autopsy livers of hepatolithiasis. In the latter, bacterial infection was constantly found. Lactoferrin and lysozyme were detected in low doses and in specific areas in the intramural and extramural glands of certain normal livers. In contrast, in hepatolithiasis, the incidence of lactoferrin- and lysozyme-positive cases significantly increased both in the intramural glands (94% and 77% of 31 cases, respectively) and in the extramural glands (72% and 48% of 29 cases, respectively) ( p < 0.01) in the stone-containing bile ducts. These glands proliferated considerably in the stone-containing bile ducts and were stained more widely and intensely than in normal livers. These data suggest that these proliferated peribiliary glands in the stone-containing bile ducts produce and secrete significant amounts of lactoferrin and lysozyme. Increased production and secretion of lactoferrin and lysozyme suggests activated local defense mechanisms against bacterial infection in the stone-containing bile ducts, and may be beneficial for inhibition of the growth of calculi and prevention of the suppurative inflammation.

Pathologic observations of intrahepatic peribiliary glands in 1,000 consecutive autopsy livers: IV. Hyperplasia of intramural and extramural glands

Hyperplastic changes of intrahepatic peribiliary glands have rarely been reported, with the exception of hepatolithiasis. To determine whether there are any hyperplastic changes in the glands in livers without hepatolithiasis, we examined 1,000 consecutive autopsy liver specimens that had no hepatolithiasis. The glands were divided into intramural mucous glands and extramural seromucous glands. The hyperplastic changes were found in “normal” livers and in livers with various hepatobiliary diseases, and they were classified into three categories: hyperplasia of intramural glands (49 cases; 4.9%), hyperplasia of extramural serous acini (35 cases; 3.5%), and hyperplasia of extramural mucous acini (92 cases; 9.2%). Two or more of these three hyperplastic changes occasionally coexisted in the same liver. Hyperplasia of intramural glands was seen rather evenly in normal livers and in livers with various hepatobiliary diseases. Prevalence of hyperplasia of extramural serous acini was high in intrahepatic cholangitis and submassive hepatic necrosis. Prevalence of hyperplasia of extramural mucous acini was high in cirrhosis, submassive hepatic necrosis, cholangitis, systemic infection, and extrahepatic biliary obstruction. The hyperplastic intramural glands and mucous acini of extramural glands contained more neutral, carboxylated, and sulfated mucin than normal glands. Although their pathogenesis is unclear, these hyperplastic changes may enhance seromucous secretion into biliary lumens and may lead to biliary dysfunctions such as retardation of bile flow and increased bile viscosity. These hyperplastic changes may be preexisting conditions predisposing to hepatolithiasis.

Immunohistochemistry with keratin and smooth muscle actin monoclonal antibodies in canine digestive tract and extramural glands.

The canine digestive system and its extramural glands (parotid gland, liver, pancreas) were immunohistochemically studied using a panel of twelve monoclonal antibodies (MoAbs) specific for human keratin proteins and for alpha-smooth muscle actin. Various epithelial tissues and cells were characterized by different keratin staining patterns. So, the epithelial lining of the upper alimentary tract was characterized by staining with the MoAb 6B10, specific for keratin-type (K) 4, and the absence of staining with the MoAbs directed against K 8 and 18 (CAM 5.2 and RGE 53, DE-K18 respectively), whereas the lower alimentary tract epithelium was not labeled by 6B10, but stained by the latter MoAbs. In the salivary glands the luminal and basal cells of the adenomeres as well as the different ductal structures could be immunohistochemically differentiated. The duct epithelium in liver and pancreas showed next to keratin staining characteristics in common with hepatocytes and exocrine pancreatic cells, additional staining by several keratin MoAbs. The keratin staining patterns in the canine tissues showed, in addition to similarities also distinct discrepancies when compared to the staining patterns in corresponding human tissues. Myoepithelial cells in salivary and oesophageal glands could be differentiated from other basally located epithelial cells by their exclusive immunoreactivity for alpha-smooth muscle actin. Canine pancreatic endocrine cells were not labeled by any of the keratin MoAbs. It is concluded that immunohistochemistry with polypeptide specific MoAbs specific for human keratin-types can be used to differentiate between different types of canine epithelial tissues and epithelial cells in the digestive tract. As a result such reagents may find their application in developmental biology and pathology of this species.

Morphological examination of intrahepatic bile ducts in hepatolithiasis.

Numerous glandular elements are characteristically found within and around the intrahepatic bile duct walls in hepatolithiasis. These glandular elements were studied by reconstruction of serial sections and mucus histochemistry. The glands were of two types: glands within the thickened ductal wall (intramural) and those outside the wall (extramural). The former were mucous glands arranged in tubular pattern and the latter seromucous glands arranged in tubuloalveolar pattern. Mucous acini of both glands were rich in neutral, carboxylated and sulfated mucus glycoproteins. Serial section observations showed that the intramural glands communicated with bile duct lumina directly, and the extramural glands with ductal lumina via their own conduits. The intramural glands were usually continuous with the epithelia lining bile ducts, suggesting that they were derived from an invagination and subsequently proliferating epithelium lining bile ducts. The extramural glands may have arisen from a proliferation of the pre-existing peribiliary glands. Hypersecreted mucus from the intramural and extramural glands might be causally related to the development and growth of calculi in the intrahepatic biliary tree.

Glandular elements around the intrahepatic bile ducts in man; their morphology and distribution in normal livers.

The morphology and distribution of the glandular elements around the intrahepatic bile ducts, hitherto poorly described, were examined in autopsied human livers with the aid of postmortem cholangiographs. The glands could be divided into intramural and extramural. The former were small in number, scattered within the bile duct walls, and were simple tubular mucous glands. The latter were more abundant, located in the periductal connective tissue, and were branched tubuloalveolar seromucous glands. Serial section observations revealed that neither gland communicated with the hepatic parenchyma, and the extramural glands drained into the large bile duct lumina via the conduits. The mucous cells of both glands contained neutral, carboxylated and sulfated glycoproteins. The extramural glands were distributed from the hepatic to the segment ducts in almost all livers, and were also discerned around the area ducts in two-fifths of the livers. The glands seemed to decrease in number as the bile ducts became more branched.