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.

Mallory body clustering in adenomatous hyperplasia in human cirrhotic livers: report of four cases.

We report four cases of liver cirrhosis in which seven nodules of adenomatous hyperplasia (AH) were present. Each nodule contained one to several foci of hepatocytes with Mallory bodies (MBs). All of these foci were well-circumscribed lesions located within the nodules of AH. The cells containing MBs showed variable degrees of atypia. At least two of the foci were considered to represent a recent proliferation of the cells containing MBs, possibly premalignant foci, because they showed resistance to the accumulation of stainable iron in siderotic background. From these observations, it was suggested that the MB-containing hepatocellular clusters in AH might have occurred as the result of proliferation in small foci and that at least some of them may be related to hepatocarcinogenesis in humans.

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.

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.

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.

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.

Cytophotometric DNA analysis of adenomatous hyperplasia in cirrhotic livers.

The possibility of adenomatous hyperplasia (AH) being a precursor lesion of hepatocellular carcinoma (HCC) in human cirrhotic livers was investigated. Feulgen DNA cytophotometry was used to measure the DNA content of the hepatocytes in 13 AH nodules obtained from six cirrhotic livers. DNA distribution patterns were classified into types I (diploid pattern), II (hyperploid pattern) and III (aneuploid pattern). According to the cellular and structural atypia, AH nodules were divided into ordinary type (2 nodules) and atypical type (11 nodules), 6 of the latter possessing foci of apparent HCC within them. Two ordinary AH nodules showed a type I DNA distribution pattern, similar to the surrounding regenerative nodules. A major part of the atypical AH nodules also showed type I. However, small foci showing moderate and structural atypia within these atypical AH nodules presented a type I pattern with more hyperploid cells and some aneuploid cells and also a type II histogram pattern with some aneuploid cells. Neoplastic foci, found within 5 atypical AH nodules, displayed various patterns (type I, II, III) as seen in well-developed HCC nodules. These data may imply that atypical AH nodules are precursor lesions of HCC, or are actually undergoing malignant transformation. It is apparent that at least some HCCs occurring in liver cirrhosis evolve through AH.

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.

Clinicopathological characteristics of hepatocellular carcinoma bearing Mallory bodies: an autopsy study.

Mallory bodies are known to occur in hepatocellular carcinoma. The simple question whether or not there are any clinicopathological features characterizing Mallory body-positive hepatocellular carcinoma remains unresolved to date. The present study of 200 consecutive autopsy cases of hepatocellular carcinoma showed several important differences between 49 cases bearing Mallory bodies and 151 cases bearing no Mallory bodies in carcinoma cells. The patients in the former group were older, showed a higher association rate of liver cirrhosis, and their liver weight was lighter. As to the gross pathology of hepatocellular carcinoma, the nodular type was relatively frequent in Mallory body-positive hepatocellular carcinoma, while the massive and diffuse types were relatively frequent in Mallory body-negative cases. The frequency of extrahepatic metastases in the Mallory body-positive group was lower than that in the Mallory body-negative cases. The reasons for these differences remain speculative.

Cytophotometric DNA analysis of hepatocellular carcinoma with Mallory bodies.

In order to clarify the pathological significance of Mallory body (MB) formation in human hepatocellular carcinoma (HCC), cell nuclear deoxyribonucleic acid (DNA) content was measured microspectrophotometrically in 20 autopsied cases of HCC associated with cirrhosis and bearing many MBs. According to the degree of dispersion, the DNA histogram was classified into type I (diploid pattern), type II (hyperploid pattern) and type III (aneuploid pattern). Non-neoplastic hepatocytes of normal livers and of cirrhotic areas of the 20 HCC cases showed generally a diploid pattern (type I). In contrast, MB-positive HCC cells showed more hyperploidy or aneuploidy (type I: 0%; type II: 35%; and type III: 65%) compared with MB-negative HCC cells (type I: 25%; type II: 50%; and type III: 25%). These data suggest that MB formation in HCC is accompanied by a constant change of DNA content of HCC cells, though the causal relation between them is only speculative. Two separate HCC nodules in the same liver, both of which contained many MB-positive cells, showed the same type of DNA histogram pattern, suggesting the possibility that they were of a monoclonal origin and had spread discontinuously in the liver.

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)

Development of cavernous vasculatures in livers with hepatocellular carcinoma. An autopsy study.

The incidence and morphology of cavernous vasculatures in livers with hepatocellular carcinoma were examined. These vasculatures were grossly or microscopically found in 64% of 102 autopsied livers with hepatocellular carcinoma, though the incidence of grossly visible vasculatures was only 7%. These vasculatures were preferentially found within the portal tracts in the vicinity of portal veins obstructed by tumor emboli, especially in the cases with marked tumor emboli of the portal venous system. A majority of these vasculatures showed histochemical and immunohistochemical characteristics of blood vessels. Our findings suggest that these vasculatures frequently develop as collaterals of portal veins obstructed by the tumor emboli in hepatocellular carcinoma.

Microvasculature in the small portal tracts in idiopathic portal hypertension. A morphological comparison with other hepatic diseases.

The morphology of the microvasculature in the small portal tracts was examined in normal livers, idiopathic portal hypertension (IPH) and other hepatic diseases. The microvasculature examined was arbitrary divided into two groups: that near the limiting plate and that within portal tracts, particularly around bile ducts. Based on comparisons of histology, immunohistochemistry and vascular casts, it is suggested that the former corresponded to inlet venules and the latter to distributing portal veins and peribiliary capillary plexus. Both of these microvasculatures were positive for Ulex europaeus lectin I, and (infrequently and weakly) for factor VIII-related antigen. Morphometry disclosed that inlet venules were reduced in number in IPH compared with normal livers and that distributing portal veins, peribiliary capillary plexus and inlet venules were increased in extrahepatic portal obstruction, chronic active hepatitis and extrahepatic obstructive cholestasis. We believe that the change in the microvasculature reflects abnormal microcirculation in the small portal tracts, and that the reduction of inlet venules plays an important role in the development of portal hypertension in IPH.

Expression of HLA-DR antigen on hepatic vascular endothelial cells in idiopathic portal hypertension.

Immunologic abnormalities have been reported in idiopathic portal hypertension, though the exact immunologic mechanism(s) leading to various portal venopathies in this disease remain unsettled. Recently, aberrant expression of HLA-DR antigen on target cells has been noted in the organ-specific autoimmune diseases. In this study the expression of HLA-DR antigen on the hepatic vasculature was surveyed immunohistochemically in idiopathic portal hypertension (n = 36) and in control livers: normal livers (n = 27), chronic active hepatitis (n = 35) and cirrhosis (n = 21). Endothelial cells of hepatic veins and hepatic arteries occasionally expressed HLA-DR antigen, and there was no difference in the expression between idiopathic portal hypertension and controls. Endothelial cells of the main portal vein, within the small and medium-sized portal tract, did not express HLA-DR antigen in idiopathic portal hypertension and controls. By contrast, endothelial cells of the smaller venous radicles, including inlet venules in these portal tracts other than the main portal vein, more frequently expressed HLA-DR antigen in idiopathic portal hypertension (78%) than in chronic active hepatitis (26%), cirrhosis (29%) and normal liver (15%). These data raise the possibility that the smaller venous radicles in the small and medium-sized portal tracts are targets of immunologic attack in idiopathic portal hypertension.

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.

Atrophy and ductopenia of the right hepatic lobe in a patient with choledocholithiasis.

An extremely rare case of atrophy and extensive ductopenia of the right hepatic lobe is presented. The surgically resected atrophic right lobe (100 g) did not show cholestasis or cirrhosis. The right hepatic bile duct revealed sclerosis with luminal obliteration and marked diminution of its branches. The extrahepatic bile duct contained a single cholesterol stone. The right portal vein branches showed luminal narrowing. Disturbance of biliary drainage following sclerosing cholangitis and impediment of portal venous flow in the right hepatic lobe were considered responsible for atrophy of the lobe. Although choledocholithiasis presumably played an important part in the pathogenesis of the sclerosing cholangitis and ductopenia, the reason for selective involvement of the right biliary tree remains nuclear.

Pathologic study of primary biliary cirrhosis of early histologic stages presenting cholestatic jaundice.

While cholestatic jaundice usually develops in the advanced stages of primary biliary cirrhosis, our series of this disease disclosed that 8 of the 88 cases presented cholestatic jaundice in the early histologic stages (stages 1 and 2). These patients frequently presented esophageal varices (57%) and showed a low incidence of positive mitochondrial antibodies compared to the non-jaundices cases in the same histologic stages. Histologic changes of livers from the jaundiced patients failed to show fundamental differences from those of the non-jaundiced patients, except for the presence of bile plugs and extensive bile duct loss in the former. Deposition of orcein-positive granules and increased hepatic copper content, suggesting prolonged cholestasis, were rather advanced, and inflammatory changes in the portal tracts and piecemeal necrosis were rather mild in the jaundiced patients. These data suggest that cholestatic jaundice occurs in a few patients in the early histologic stages on a biopsy with extensive bile duct loss and features of prolonged cholestasis; it is not clear whether such patients are a small separate cluster in PBC, or not.