Joint unloading inhibits articular cartilage degeneration in knee joints of a monosodium iodoacetate-induced rat model of osteoarthritis.

OBJECTIVE: The aim of the study was to examine how mechanical unloading affects articular cartilage degeneration in the patellofemoral (PF) and tibiofemoral (TF) joints of a monosodium iodoacetate (MIA)-induced rat model of osteoarthritis (OA). DESIGN: The study involved 60 male rats. OA was induced by intra-articular injecting MIA into both knee joints. All animals were equally divided into two groups: sedentary (SE) and hindlimb unloading (HU) groups. Histopathological changes in the articular cartilage of the PF and TF joints were evaluated using the Osteoarthritis Research Society International (OARSI) score and modified Mankin score at 2 and 4 weeks after MIA injection. RESULTS: In the SE and HU groups, representative histopathological changes in OA were detected in the PF and TF joints. The OARSI and modified Mankin scores for the PF and TF joints tended to increase over time after the injection of 0.2 mg or 1.0 mg of MIA in the SE and HU groups. Both the scores for the HU group were significantly lower than those for the SE group [OARSI score: P < 0.0001 (1.0-mg injection at 4 weeks); modified Mankin score: P = 0.0116 (0.2-mg injection at 4 weeks); P = 0.0004 and < 0.0001 (1.0-mg injection at 2 and 4 weeks, respectively)]. CONCLUSION: This study revealed new histological evidence that indicates that unloading condition suppresses articular cartilage degeneration and is beneficial in many areas of basal and clinical research involving OA.

An unusual case of epithelial-myoepithelial carcinoma of the liver.

The authors present an unusual case of an epithelial-myoepithelial carcinoma of the liver in a 67-year-old man who was admitted for resection of a gastric adenocarcinoma. At operation, a 3 x 3 cm mass in the right liver lobe was also removed. This mass consisted of duct-like structures with dual differentiation. The inner layer was composed of an epithelial lining, and the outer layer consisted of clear cells, all unrelated to the moderately well-differentiated gastric adenocarcinoma. The clear cells were positive for S-100 and alpha-smooth muscle actin, suggesting myoepithelial origin. The mass was considered to be low-grade epithelial-myoepithelial carcinoma. However, the patient had a history of an oral nodule present since childhood, resected 10 years previously. These slides were reviewed and revealed a mixture of clear cells and basal cells with squamous differentiation. In addition, there were duct-like structures with the two-layer pattern found in the liver tumor. This tumor had numerous mitotic figures and showed perineural invasion, suggesting a high grade of malignancy. These findings led to an interpretation of the oral tumor as also being epithelial-myoepithelial carcinoma, which had remained as "benign" for more than 50 years and subsequently underwent malignant transformation. During this long period, liver metastases may have occurred and remained low-grade. Alternatively, the liver and oral tumors may have arisen separately in the foregut during embryologic development, remaining low-grade until malignant transformation occurred.

aly/aly mice: a unique model of biliary disease.

An autosomal recessive murine mutation, coined "aly/aly" or "alymphoplasia," was recently reported. Homozygotes for aly are defective in both humoral and cell-mediated immune function and have diffuse lymphoid cell infiltration of various tissues, particularly around the conduit ducts of the pancreas and salivary glands. In pilot studies in our laboratories, aly/aly mice were found to have peculiar biliary tract lesions, which were analyzed histologically and immunohistochemically in the present study. The livers of aly/aly mice older than 8 weeks consistently showed a variable lymphoid cell infiltration with lymph follicle formation in portal tracts; intrahepatic biliary epithelial cells showed various types of damage including pseudopyloric gland metaplasia and proliferative changes. In addition, the extrahepatic bile duct and intrahepatic large bile duct were found to contain an acidophilic substance in their epithelial cytoplasm. In the lumen and occasionally in the cytoplasm of these bile ducts, acidophilic crystals were also seen. Ultrastructurally, the intracytoplasmic acidophilic substances consisted of membrane-bound intracytoplasmic inclusions with homogeneous electron density, likely derived from rough endoplasmic reticulum (ER). Immunohistochemically, the cytoplasmic acidophilic substances were simultaneously positive for cystatin C, gastrin, serotonin, and somatostatin. In contrast, the acidophilic crystals did not react with any of these antibodies. These findings suggest that the intracytoplasmic acidophilic substances may contain a precursor of the peptide hormones, possibly because of defective secretion or intracellular transport. We believe that the aly/aly mouse is a useful model for the analysis of biliary metabolic events, and for studies of the interaction of the immune system and biliary destruction.

Intrahepatic cholangiocarcinoma arising in congenital hepatic fibrosis: report of an autopsy case.

We report an autopsy case of a 60-year-old woman who had congenital hepatic fibrosis with intrahepatic cholangiocarcinoma. A white nodular lesion with a surrounding vague gray area was detected in the right lobe of the liver. Microscopically, most of the nodular lesion was a poorly-differentiated adenocarcinoma. In the surrounding gray area, small bile ducts and bile ductules showed prominent epithelial overgrowth, some of which was composed of dysplasia and well-differentiated adenocarcinoma. The background liver showed the characteristic features of congenital hepatic fibrosis. Immunohistochemically, biliary oncofetal markers (mucin core protein 1 and carcinoembryonic antigen) were more frequently and extensively expressed in poorly-differentiated than well-differentiated adenocarcinoma. This is the 4th reported case of intrahepatic cholangiocarcinoma arising in congenital hepatic fibrosis and suggests that malignant transformation via dysplasia occurs in the abnormal intrahepatic biliary tree of older congenital hepatic fibrosis patients.

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.

Granulomatous cholangitis in chronic hepatitis C: a new diagnostic problem in liver pathology.

A case of chronic hepatitis C at the pre-cirrhotic stage complicated with hepatocellular carcinoma is reported. The patient, a 64 year old female, showed elevated levels of serum alkaline phosphatase and immunoglobulin M. Antimitochondrial antibodies were negative by indirect immunofluorescence. Western blotting using beef heart mitochondria and recombinant polypeptides coding for mitochondrial antigens revealed that the patient's serum was positive only for the E2-subunit of the branched chain ketoacid dehydrogenase complex. In the non-neoplastic liver, chronic non-suppurative cholangitis surrounded by epithelioid granuloma, resembling the granulomatous destructive cholangitis of primary biliary cirrhosis, was found. The damaged bile ducts were immunohistochemically minimally positive or ambiguous for HLA-DR, and their expression of the E2-subunit of the pyruvate dehydrogenase complex E2 (PDC-E2) was diffuse or granular, and not typical of primary biliary cirrhosis. There was no bile duct loss, and orcein-positive copper binding granules reflecting chronic cholestasis were negative in periportal hepatocytes. The overall features in this case were consistent with primary biliary cirrhosis presenting an infrequent profile of antimitochondrial antibodies and atypical expression of HLA-DR and PDC-E2 on biliary epithelial cells, with late superimposition on chronic hepatitis C. However, it is also possible that this is a case of chronic hepatitis C with hepatitis-associated bile duct damage accompanied by granulomatous reaction. Either way, this case raises new diagnostic issues in the differential diagnosis of chronic liver diseases presented with granulomatous cholangitis.

Histopathology of the liver in non-cirrhotic portal hypertension of unknown aetiology.

Non-cirrhotic, long-standing portal hypertension of unknown aetiology is being re-evaluated histopathologically and clinically. In this study, we examined 107 livers with this condition (92 wedge biopsy and 15 autopsy specimens) from five institutions in Japan. These cases were histologically categorized into four groups: idiopathic portal hypertension (66 cases), nodular regenerative hyperplasia (14 cases), partial nodular transformation (two cases), and incomplete septal cirrhosis (25 cases). These four groups shared several histological features: dense portal fibrosis with portal venous obliteration and intralobular slender fibrosis. In addition, the histopathological features characteristic of one group were also found to a mild degree in other groups. The histopathological lesions preceding portal venous obliteration remain speculative. However, the portal venous obliteration may be responsible for the occurrence of sustained portal hypertension and several of the pathological changes in these livers. It seems likely that idiopathic portal hypertension, nodular regenerative hyperplasia, partial nodular transformation and incomplete septal cirrhosis comprise a family of non-cirrhotic, long-standing portal hypertension in Japan, and the histological differences between them may reflect chronological progression of a single disease.

Carcinoembryonic antigen and blood group-related carbohydrate antigens in glycoproteins in human bile in hepatolithiasis. Japanese Study Group of Hepatolithiasis.

We investigated whether carbohydrate antigens on biliary glycoproteins and carcinoembryonic antigen (CEA) are related to hepatolithiasis. CEA, ABO, and Lewis blood group-related antigens, as well as sialyl-Tn antigen in hepatic bile, were analyzed by Western blotting in samples from 12 patients with hepatolithiasis and 37 with other biliary diseases (choledocholithiasis, 13; cholecystolithiasis, 5; acute cholecystitis, 2; cholangiocarcinoma, 5; common bile duct carcinoma, 4; pancreatic carcinoma, 6; and metastatic carcinoma of liver, 2). CEA was positive on mucinous glycoprotein in six patients (50%) with hepatolithiasis and one case (17%) with pancreatic carcinoma. CEA was also positive on a glycoprotein of approximately 200 kd in eight patients (67%) with hepatolithiasis and two (33%) with pancreatic carcinoma. Lewis X was detected on the mucinous glycoprotein in almost all samples, as well as on glycoproteins of approximately 180 kd in all hepatolithiasis samples and approximately half of those from patients with other diseases. Sialyl-Tn antigen was detected on mucinous glycoprotein in four (80%) with cholangiocarcinoma, two (50%) with common bile duct carcinoma, and all pancreatic carcinoma samples. Mucinous glycoprotein and glycoproteins containing CEA and Lewis X antigens are enriched in hepatic bile of hepatolithiasis, and they may be closely related to the formation of intrahepatic calculi. Sialyl-Tn antigen in biliary mucinous glycoprotein will be a good marker of biliary and pancreatic carcinoma, and probably for cholangiocarcinoma complicated with hepatolithiasis.

Three cases of primary biliary cirrhosis associated with bronchial asthma.

The association of primary biliary cirrhosis (PBC) and bronchial asthma was observed in three patients. All of these patients were female (53, 54, and 41 years old, respectively), and were positive for antimitochondrial antibodies. The patients fulfilled the diagnostic criteria of both PBC and bronchial asthma. Bronchial asthma preceded PBC in two patients, and the reverse order was seen in the other. Patient the clinical symptoms were mainly due to the bronchial asthma. Two patients had asymptomatic PBC and the third patient complained of pruritus. The liver histology showed mild to moderate eosinophilic infiltration in addition to the ductal and hepatic parenchymal changes characteristic of PBC. A survey of 266 cases of PBC referred to us disclosed that, in 6 of these, the PBC was associated with bronchial asthma, while no association with bronchial asthma was the material of found in 166 patients with viral hepatitis in our liver biopsy files. The 3 present cases we experienced suggest that bronchial asthma may be included in the list of extrahepatic diseases associated with PBC. The significance of this association is unclear and may merit further study. Steroid therapy, which is known to cause adverse effects in PBC, was employed for bronchial asthma in these 3 patients. Another therapeutic approach will have to be considered in patients with bronchial asthma associated with PBC.

Poorly differentiated ('insular') carcinoma of the thyroid.

Three cases of unusual poorly differentiated ('insular') carcinoma of the thyroid gland are presented. These three thyroid carcinomas were large; the tumors from patients 1 and 3 were encapsulated, and that from patient 2 showed invasive growth. Microscopically the tumors were characterized by well-defined solid nests (insulae), which were composed of rather small and uniform tumor cells with round to oval nuclei. Formation of small and colloid-containing follicles was associated with these nests to varying degrees. The tumors of patients 1 and 3 were composed entirely of insular components, but that of patient 2 was associated with small areas of well-differentiated follicular carcinoma. The metastatic tumors of patients 1 and 2 were essentially similar to the primary with small foci of follicular carcinoma. Patient 1 is alive with local and mediastinal node recurrences, but patient 2 died of the disease with local recurrences and metastases to lungs, bones and skin. Patient 3 had no recurrences and died of unrelated disease 5 years after surgery. The present study indicates that insular carcinomas have characteristic histologic features and a less favorable prognosis, confirming the findings of previous studies.

Distribution of cytokeratin 19-positive biliary cells in cirrhotic nodules, hepatic borderline nodules (atypical adenomatous hyperplasia), and small hepatocellular carcinomas.

Borderline nodule (BN) in the cirrhotic liver is considered to be a precancerous lesion leading to hepatocellular carcinoma (HCC). We investigated the distribution of cytokeratin 19 (CK 19)-positive biliary cells, recognizable by a monoclonal antibody AE1, in normal livers, chronic active hepatitis, cirrhosis, BN, and small HCC. The CK 19-positive biliary cells in the hepatic parenchyma were clearly divisible into two types (I and II). Type I cells were located within the hepatic parenchyma as small clusters forming small tubules (intraparenchymal ductules). Type II cells were bile ductules located in the peripheral rim of the hepatic lobules or hepatocellular lesions (peripheral ductular reaction) and were continuous with proliferated bile ductules in fibrous septae or portal tracts. In chronic active hepatitis and regenerative nodules of cirrhosis, a few type I cells and a variable number of type II cells were present. In the BN, all cases harbored a few type I cells as well as a variable number of type II cells. The type II cells in the BN were fewer in number and more randomly distributed than those in chronic active hepatitis and cirrhosis. Malignant foci in some BNs lacked CK 19-positive biliary cells. In small HCC, no CK 19-positive biliary cells were found; instead, AE1-positive HCC cells were present in three cases (17%). Although a great majority of type I cells corresponded to intraparenchymal ductules, some type I cells in the BN were composed of rather large tubules considered as interlobular bile ducts.(ABSTRACT TRUNCATED AT 250 WORDS)

Biliary epithelial expression of pyruvate dehydrogenase complex in primary biliary cirrhosis: an immunohistochemical and immunoelectron microscopic study.

It has been reported recently that there is a unique distribution of the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2) on biliary epithelial cells in patients with primary biliary cirrhosis (PBC) but not primary sclerosing cholangitis. This distribution has been demonstrated using a mouse monoclonal antibody, coined C355.1. The epitope recognized by C355.1 is near the lipoic acid binding site of PDC-E2. C355.1 inhibits PDC-E2 activity in vitro and, unlike a panel of other monoclonal antibodies against different regions of PDC-E2, appears to bind not only to mitochondria but also to a unique antigen expressed predominantly on the luminal side of biliary epithelial cells in PBC. We have extended these observations by studying the subcellular reactivity of C355.1 using postembedding immunoelectron microscopy on the intrahepatic small bile ducts of PBC livers, extrahepatic biliary obstruction (EBO) livers, and normal livers. We report that the reactivity of C355.1 can be classified into two categories. The first category is characterized by small foci of reaction products that were randomly dispersed in cytoplasm, particularly in supranuclear areas; the ultrastructural characterization of these foci was impossible to define but was similar in PBC and EBO. However, of particular interest was the second category of reactivity, which was characterized by deposition of reaction products around the biliary lumen, including microvilli and adjacent subluminal ectoplasm and secretory substances in the biliary lumen. This staining pattern was frequent in PBC livers, only occasionally evident in EBO livers, and not found in normal livers. These data further define and highlight the unique subcellular distribution of PDC-E2 around the biliary lumen in PBC livers and suggest that this abnormality is related to the pathogenesis of bile duct lesions.

Partial nodular transformation of the liver with portal vein thrombosis. A report of two autopsy cases.

Partial nodular transformation (PNT) of the liver is a rare condition in which nonfibrous nodules composed of hyperplastic hepatocytes replace the hepatic parenchyma around the hepatic hilus. We report two autopsy cases involving PNT of the liver with portal vein thrombosis. Case 1 was a 27-year-old man with malignant lymphoma. Ascites gradually increased, and he died 4 years after the onset of his illness. Case 2 was a 73-year-old woman treated for cirrhosis for 4 years who died of renal failure. Postmortem examination of these two cases revealed numerous coalescent nodules in the hilus of the liver as well as portal vein thrombus in the hilus. Microscopically, these nodules in the perihilar area were composed of hyperplastic hepatocytes without fibrous rim, and the peripheral parenchyma showed atrophy to some extent. The portal vein thrombi in the hilus and large portal tracts were mainly fresh and partially organized. Portal vein branches in the peripheral small portal tracts were devoid of significant pathologic changes. We suggest that PNT of the liver in our cases occurred as the result of uneven blood supply to the perihilar parenchyma due to portal vein thrombosis in the hepatic hilus.

Pancreatic enzymes in the epithelium of intrahepatic large bile ducts and in hepatic bile in patients with extrahepatic bile duct obstruction.

AIM: To determine whether pancreatic enzymes are present in hepatic bile and in intrahepatic bile duct epithelium. METHODS: The activity and proteins of pancreatic enzymes (pancreatic alpha-amylase, lipase, trypsin/trypsinogen) in hepatic bile were investigated using biochemical and western blot analyses in 25 patients with extrahepatic bile duct obstruction. Immunolocalization of enzyme proteins was evaluated by immunohistochemistry in 20 necropsy livers with extrahepatic bile duct obstruction. RESULTS: Western blot analysis showed proteins of pancreatic alpha-amylase, lipase, and trypsin in 19 of 25 (76%), 10 of 25 (40%), and 14 of 25 (56%) patients, respectively. Pancreatic alpha-amylase and lipase activities was present in every bile specimen. Radioimmunoassay showed that trypsin was present in every bile sample. Immunohistochemically, the immunoreactivity of the three enzymes was present in epithelia and in the lumina of intrahepatic large bile ducts, septal bile ducts, and peribiliary glands in all cases. CONCLUSIONS: These results strongly suggest that biliary epithelia of larger intrahepatic ducts produce pancreatic alpha-amylase, lipase, and trypsin, and that these enzymes are secreted into the lumina of intrahepatic bile ducts.

Argyrophilic nucleolar organizer regions in neoplastic and non-neoplastic hepatocytes bearing Mallory bodies.

The proliferative activity of Mallory bodies (MB)-positive hepatocytes (neoplastic and non-neoplastic) was examined by counting the argyrophilic nucleolar organizer regions (AgNORs). Among 19 cases of hepatocellular carcinoma, the mean number of AgNORs was lower in the MB-positive carcinoma cells than in the negative ones in nine cases, higher in six, and there was no difference in four. In non-neoplastic cases (seven cases of advanced primary biliary cirrhosis and seven cases of alcoholic or nutritional liver injury), the mean number of AgNORs was lower in the MB-positive hepatocytes than that in the negative ones in eight cases, and approximately equal in number in six cases. These findings imply that MB formation does not directly represent the level of proliferative activity of hepatocytes, regardless of whether they are malignant or not.