Destructive cholangiolitis in seven dogs

In seven dogs presented with clinical signs and laboratory data suggestive of extrahepatic cholestasis, destructive cholangiolitis was diagnosed. The diagnosis was based on the absence of extrahepatic cholestasis at laparoscopy, laparotomy and/or post-mortem examination, and the presence of specific liver lesions i.e. loss of bile ducts in the smaller portal areas. The disease is compared with drug-induced (chlorpromazine) cholestasis in man. In two dogs clinical signs were preceded by longstanding respectively repeated sulphonamide medication.

Bile canalicular morphometry in arteriohepatic dysplasia

The diagnosis of arteriohepatic dysplasia may be difficult, particularly in very young patients with no family history, and the pathogenesis of the disorder remains obscure. It has been reported that the typical ultrastructural changes of cholestasis are scant in this condition and proposed that there is a failure of the hepatocytes to secrete bile into the canaliculi. In an attempt to expand on these observations and to test the value of ultrastructure as a differential diagnostic test for this condition, we chose two parameters felt to be associated with cholestasis that could be reliably and relatively simply determined by ultrastructural morphometry: canalicular dilatation and loss of canalicular microvilli. The values for these parameters were compared in arteriohepatic dysplasia with those in other infantile cholestatic conditions and with those in noncholestatic controls. The results of these morphometric studies corroborated the previous observation that canalicular dilatation in arteriohepatic dysplasia is minimal. There was, however, only a marginal difference in canalicular area between patients with arteriohepatic dysplasia and those with extrahepatic biliary atresia. There was significant overlap of values for canalicular area among all groups. Surprisingly, the studies showed no real loss of canalicular microvilli in any of the cholestatic conditions. The findings suggest that, at least for these two parameters, caution should be exercised in using qualitative electron microscopic evaluation as a diagnostic test for arteriohepatic dysplasia.

Hepatocanalicular injury associated with vitamin A derivative etretinate. An idiosyncratic hypersensitivity reaction

A patient with pustular psoriasis developed jaundice, peripheral blood eosinophilia, and biochemical evidence of hepatocanalicular dysfunction four weeks after the initiation of etretinate therapy. A liver biopsy specimen showed bile duct damage, a periportal inflammatory infiltrate composed of neutrophils, eosinophils and lymphocytes, canalicular cholestasis, and focal hepatocyte necrosis. Clinical exclusion of other possible etiologic factors coupled with near resolution of the biochemical abnormalities within six weeks after complete discontinuation of the drug indicates that etretinate may induce an idiosyncratic hypersensitivity reaction. This is the first report to document etretinate associated bile duct injury.

Pseudoglandular hepatocellular carcinoma. A morphogenetic study

A histopathologic study of pseudoglandular formation was made by observing selected 39 cases of hepatocellular carcinoma (HCC). The pseudoglands were most often derived from the dilatation of bile canaliculi (28/39). The dilated canaliculi were sometimes connected and divided a cell trabecula to give a pseudopapillary appearance. A second type was concerned with tumor cell necrosis and subsequent pseudoglandular formation (6/39). A rare variant similar to papillary carcinoma was also seen in this group. Third, five cases showed microglandular formation in an scirrhous environment thereby resembling cholangiocarcinoma or metastatic adenocarcinomas. Despite these confusing features, the overall tumor histologic features, in particular the existence of a characteristic trabecular growth pattern made it possible to determine all of the cases as HCC. The importance of noticing these variable manifestations of HCC is yet emphasized in regard to differential diagnosis of hepatic tumors. The glandular elements seen in two cases of combined HCC and cholangiocarcinoma differed in that they were positive for mucin staining. In addition, the tumor cells contained mucin-positive intracytoplasmic vacuoles similar to those observed in common mucin producing adenocarcinomas.

Reduced cholestatic potency of taurolithocholate during backward perfusion of the rat liver

Rat livers perfused backward are less susceptible to taurolithocholate (TLC) cholestasis than livers perfused forward. To understand this phenomenon, the uptake, metabolism, and excretion of TLC were studied in rat livers perfused forward and backward with TLC. Bolus injections of [3H]TLC were administered 20 minutes after the onset of unlabeled TLC infusion. Biliary bile acids were measured enzymatically and bile acid species were separated and quantified by thin-layer chromatography. Determination of radioactivity in each spot yielded the percentage distribution of various biliary bile acid metabolites. After perfusion, livers were examined by light and transmission electron microscopy. TLC infusion at 32 nmoles/minute/gm of liver reduced bile flow by 80% or more within 30 minutes of forward perfusion but not at all during backward perfusion. TLC uptake was over 95% regardless of perfusion direction. Although the distribution of biliary metabolites of TLC was the same during forward and backward perfusion, maximal rate of total biliary bile acid excretion was four-fold higher and total recovery of radioactivity in bile was six-fold higher during backward perfusion. Less than 6% of excreted radioactivity was in the form of unmetabolized TLC. Severe cholestasis induced by forward TLC perfusion was associated with extensive structural distortion of bile canalicular membranes almost exclusively in the periportal zone but with little hepatocellular necrosis. Livers perfused backward manifested no cholestasis. They showed cell necrosis in the pericentral zone which became extensive (10%) by 60 minutes, but the canalicular changes occurred only in a small proportion of canaliculi in the pericentral region. Bile canalicular membrane changes developed extensively only when very high doses of TLC were perfused backward. Even then, bile flow fell only 60%. We conclude: the lesser susceptibility to TLC cholestasis of livers perfused backward is in part related to the greater biotransformation and consequent excretion of TLC by pericentral hepatocytes. TLC-induced cholestasis is associated more closely with bile canalicular membrane changes than with extent of hepatocellular necrosis. The greater reduction of bile flow with periportal than with pericentral canalicular change is compatible with current concepts of biliary microanatomy which postulate a flow of bile from pericentral through periportal regions of the lobule into the bile ductules.

[Value of histopathologic findings following liver transplantation based on biopsy course studies]

A total of forty-four biopsies from nine liver transplantation patients, who had developed complications postoperatively, were studied histologically and, in part, electron-microscopically. Morphologic signs of acute rejection were seen in three patients, while there were indications of chronic rejection in one patient. In combined lesions, such as drug-induced hepatosis, cholangitis, hepatitis, and rejections, the interpretation of biopsy findings may be difficult, and special entities cannot in every case be separated unequivocally. Changes of serum bilirubin and of serum enzyme activity do not run entirely parallel to the microscopically detectable structural lesions. For diagnosis of complications after liver transplantation both the morphologic and the clinical findings must be considered.

A case report of benign recurrent intrahepatic cholestasis

A case of benign recurrent intrahepatic cholestasis was reported. A man had first experienced jaundice at the age of twenty-five, and suffered three subsequent attacks over the next five years. These attacks were characterized by prodromal severe pruritus. During the icteric phase, serum levels of total bile acids increased, most being conjugates of primary bile acids. Electron microscopy revealed that the bile canaliculi were filled with an increased volume of granular substances. Some bile canaliculi fused together resulting in the formation of abnormally elongated channels which abutted on the Disse space. These observations suggest bile regurgitation through the channel of altered canaliculi. In convalescence, these bile canaliculi disappeared. Every attack was followed by complete recovery of liver structure and function.

Isolation, culture and characterization of adult human hepatocytes from surgical liver biopsies

A technique is described for isolation and culture of adult human hepatocytes from surgical liver biopsies. The mean cell yield was 1.75 X 10(7) cells per gm liver and viability averaged 80%. Hepatocytes were maintained in primary culture for about 10 days. Cell morphology and histochemical characteristics were similar to hepatocytes in vivo. Bile canaliculi were observed by electron microscopy. Intracellular albumin was demonstrated up to the 7th day of culture; albumin secretion rate was maximal (0.6 +/- 0.33 micrograms per hr per 10(6) cells) 5 days after plating. These studies demonstrate that adult human hepatocytes can be isolated from surgical biopsies with high yield, and differentiated function can be maintained for several days.

Intrahepatic cholestasis as a canalicular motility disorder. Evidence using cytochalasin

A rich network of actin-containing microfilaments are associated with the plasma membrane of the liver cells. These filaments are especially numerous in the pericanalicular region. Recently, active contractions of bile canaliculi have been observed in normal coupled isolated hepatocytes. In this report, we document that this motility behavior is abolished by cytochalasins B and D. Other cytoplasmic contractile movements are also reduced or lost after a brief initial period of enhanced surface activity with the formation of zeiotic blebs. The lack of contractile activity of bile canaliculi is accompanied by the gradual dilation of canalicular lumina. Since there is overwhelming evidence that the functional effects of the cytochalasins on cell motility are due to their effects on actin filaments, we propose that the altered canalicular contractility observed is due to the effects of cytochalasin on pericanalicular actin filaments. If bile canalicular contractility is a requirement for normal bile flow, then interference with this mechanism may be a factor in the pathogenesis of some types of intrahepatic cholestasis.

Bile canaliculi morphology after bile duct ligation in the rat with portacaval shunt: a time course study

Besides the spontaneous occurrence of portacaval shunts in chronic liver diseases and the performance of shunt to cure portal hypertension, shunts are now proposed for the treatment of some metabolic diseases, especially in children. The portacaval shunt model in the rat, known to induce liver atrophy related to hepatocyte loss and atrophy, was used to investigate morphological liver changes occurring in cholestasis. Two weeks after portacaval or sham portacaval shunt, the bile duct was ligated and livers were examined by light and electron microscopy at 5 h, 20 h, 4 days and 8 days. Portal inflammatory reaction and proliferation of bile ducts were identical but areas of patchy hepatic necrosis were more numerous in shunted rats. Hepatocyte size decreased in the sham group but increased in the other group. Hepatocyte ultrastructural changes were similar in the two groups. At 5 h, the number of bile canaliculi sections increased (X2) and 95% of them were normal. As time elapsed, the ratio of dilated bile canaliculi without microvilli and of bile canaliculi filled with cytoplasmic blebs increased but in no case reached 50% of the total. These results show that in the rat, cholestasis induced by bile duct ligation has approximately the same characteristics in control or shunted animals.

Morphologic structure of bile canaliculi after bile duct ligation in the rat. A time-course study

Changes in bile canaliculi (BCs) after bile duct ligation (BDL) are heterogeneous throughout the liver lobule. Male Wistar rats were killed five hours, 20 hours, four days, or eight days after BDL, and BCs were counted according to their shape (1, normal; 2, elongated with microvilli; 3, dilated, devoid of microvilli; or 4, filled with blebs). Compared with controls, the number of BCs doubled after BDL, less than 10% of the BCs were of type 3. As time elapsed, the ratios of types 3 and 4 increased; however, their combined ratio always was below 50%, and remained stable between days 4 and 8. Bilirubin levels peaked between days 2 and 4, then remained stable. The heterogeneous changes in BCs could be explained by the heterogeneous tightness of tight junctions. Decrease in cell size and increase in the size of BC branches could favor contact between bile and blood.

Hepatotoxicity of bile acids in rabbits: ursodeoxycholic acid is less toxic than chenodeoxycholic acid

The hepatotoxic effects of cholelitholytic bile acids, ursodeoxycholic and chenodeoxycholic acids, were compared with each other and with those of lithocholic acid, a known hepatotoxic bile acid, in the rabbit. Male New Zealand white rabbits were fed regular laboratory chow containing ursodeoxycholic, chenodeoxycholic, or lithocholic acid at a concentration of 0.5 per cent (w/w) for 14 days. The control group was fed the chow without added bile acids. The mortality rate was highest (six of 12) in the lithocholate group, intermediate (two of eight) in the chenodeoxycholate group, and lowest (none of six) in the ursodeoxycholate group. Light microscopy of the liver revealed fibrosis, inflammation, and bile duct proliferation in the portal regions in the three experimental groups; however, the lesions in the lithocholate and chenodeoxycholate groups were more severe and often associated with periportal extension of fibrosis and focal necrosis of the parenchyma. In addition, electron microscopy revealed distortion of bile canaliculi, conspicuous bundles of intermediate-sized filaments, expansion of pericanalicular cytoplasmic matrix due to apparent accumulation of microfilaments, prominence of lysosomes, and fragmentation of cisternae of the rough endoplasmic reticulum. These ultrastructural changes were less marked and often absent in the ursodeoxycholate group. The serum L-alanine aminotransferase activity increased 5- to 6-fold in the lithocholate and chenodeoxycholate groups, whereas it remained less than 2-fold of the control level in the ursodeoxycholate group on day 14. The serum lithocholate concentration was markedly elevated to comparable levels in all three groups, whereas ursodeoxycholate was highly increased in the ursodeoxycholate group but undetectable in the other groups at the time of sacrifice. It is concluded that (1) although the oral administration of three bile acids induces hepatic injuries in the rabbit, ursodeoxycholate causes less severe injury than do the other two, (2) the advantage of ursodeoxycholate versus chenodeoxycholate is probably relative rather than absolute, (3) lithocholate formed through metabolic conversion from ursodeoxycholate may be responsible for the most part for hepatotoxicity, and (4) it is possible that the concurrent presence of ursodeoxycholate may mitigate lithocholate's hepatotoxicity.

Microfilaments around the bile canaliculi in patients with intrahepatic cholestasis

The cytoplasmic microfilaments of hepatocytes, especially in the pericanalicular area, were examined in 25 liver biopsy specimens obtained from 15 patients with intrahepatic cholestasis. About 25 days after the onset of jaundice an increase in bile canaliculi dilation was noted, though an increase in amount of microfilaments was less conspicuous in comparison with the next stage. At about 55 days an increase in number was seen around dilated canaliculi. At about 100 days microfilaments decreased in amount and the dilation of canaliculi became less evident, while swollen microvilli protruded into the canaliculi with their microfilaments irregularly arranged. An increase of microfilaments in hepatocytes, particularly in the pericanalicular area, might be a reflection of the secretion of bile.

Opisthorchis viverrini: liver changes in golden hamsters maintained on high and low protein diets

Two groups of hamsters maintained on eight high (25.6%) or low (5.3%) content protein diets were infected with 50 Opisthorchis viverrini metacercariae by intragastric inoculation. Three animals from each group were sacrificed at 14-day intervals over a 32-week period. Two groups of non-infected control animals maintained on identical diets were killed at similar intervals. Histological examination revealed qualitatively similar pathological responses to the parasite in both diet groups, but overall the low protein diet group had the more severe lesions. Two weeks after infection, second order bile ducts showed epithelial focal necrosis, reactive hyperplasia and folding of the bile duct epithelium with some periductal fibrosis. Periductal inflammatory cells were predominantly eosinophils and lymphocytes at this time, changing after six weeks to predominantly lymphoblast and plasma cell infiltrates. Central bile ducts showed maximal concentric fibrosis at 12 weeks and this was considerably more pronounced in high protein fed animals. The small peripheral bile ductules proliferated and by four weeks post-infection, adjacent portal tracts appeared linked together, until at eight weeks some of the livers were nodular. The degree of bile ductule proliferation was markedly more pronounced in the low protein fed animals such that by 12 weeks parts of the peripheral liver substance was obliterated by proliferating ductules. No tumours or evidence of premalignant lesions were detected in livers from any of the infected animals, but it is likely that the infection period was rather too short for malignant transformation to ensue. The possible pathogenetic mechanisms operating in this animal model of opisthorchiasis are discussed with particular reference to the disease in man.

Hepatic fibrosis. The relation between proliferating bile ductules and alpha1-antitrypsin

Since there is a remarkable increase in connective tissue around the proliferating bile ductules in chronic hepatitis and liver cirrhosis, the participation of proliferating bile ductules in hepatic fibrosis has been discussed by many during the past. With the use of immunofluorescent method, the present authors have recently succeeded in detecting alpha1-antitrypsin, a protease inhibitor, in the epithelial cells of proliferating bile ductules and a portion of the hepatocytes connected with these epithelial cells. When considering the posibility of alpha1-antitrypsin being secreted into the interstitial tissue, it is conceivable that this glycoprotein plays an important role in restraining collagenase activity, which takes part in the degradation of collagen, and leads to abnormal proliferation of collagen.