Biliary Proliferation Research Articles

Morphometric Studies of Cystic and Tubulointerstitial Kidney Diseases with Hepatic Fibrosis in Children

Portal tract fibrosis with biliary ductular enlargement or proliferation occurs in a number of genetic diseases that have cystic or tubulointerstitial renal lesions. These include some with renal cystic disease such as autosomal recessive diseases (e.g., infantile polycystic disease, juvenile polycystic disease, and Meckel's syndrome), autosomal dominant diseases (e.g., adult polycystic disease) and, rarely, tuberose sclerosis and dominant glomerulocystic disease. Portal tract fibrosis with biliary enlargement and proliferation occurs also with tubulointerstitial kidney diseases. These probably include at least three disorders in the category nephronophthisis-congenital hepatic fibrosis (one autosomal recessive disease and two either autosomal or X-linked recessive diseases) plus Jeune's syndrome (the tubulointerstitial diseases Fanconi's familial nephronophthisis and anti-tubular membrane antibody disease do not regularly cause hepatic fibrosis). Morphometric data on ratios of bile ductules to connective tissue in hepatic portal tracts show high values for infantile polycystic disease (mean, 0.616) compared to lower values for juvenile polycystic disease (mean, 0.286). That the cystic renal lesions of the first two diseases differ in type and time course is known. Similar data on ratios of glomeruli plus tubules to connective tissue in renal cortices and of tubules to connective tissue in outer medullary zones of kidneys, respectively, are as follows: for Fanconi's nephronophthisis, 0.445 and 0.197; for anti-tubular basement membrane antibody disease, 0.585 and 0.164; and for the three types of nephronophthisis-congenital hepatic fibrosis studied, 0.668 and 0.446, 1.39 and 0.921, and 1.18 and 0.12. These data support clinical impressions that the category nephrophthisis-congenital hepatic fibrosis includes more than one disease entity.

Mutations in c-Ki-ras oncogenes in diseased livers of winter flounder from Boston Harbor.

Livers of a natural population of winter flounder from a contaminated site in Boston Harbor were examined for the presence of oncogenes by transfection of DNA into NIH 3T3 mouse fibroblasts. Tissues analyzed contained histopathologic lesions including abnormal vacuolation, biliary proliferation, and, in many cases, hepatocellular and cholangiocellular carcinomas. Fibroblasts transfected with liver DNA samples from 7 of 13 diseased animals were effective in the induction of subcutaneous sarcomas in nude mice. Further analysis revealed the presence of flounder c-Ki-ras oncogenes in all 10 nude mouse subcutaneous tumors analyzed. Direct DNA sequencing and allele-specific oligonucleotide hybridization following amplification of the tumor DNA by the polymerase chain reaction showed mutations in the 12th codon in this gene. Analysis of DNA from all nude mouse tumors as well as the livers from which they were derived showed mutations at this codon. The mutations comprised G.C----A.T or G.C----T.A base changes resulting in substitution of serine, valine, or cysteine for glycine. Liver DNA samples from five histologically normal livers of animals from a less polluted site were ineffective in the transfection assay and showed only wild-type DNA sequences (GGT) at the 12th codon of c-Ki-ras. The prevalence of mutations in this gene region was associated with the presence of liver lesions and could signify DNA damage resulting from environmental chemical exposure.

Chronic toxicity and oncogenicity studies of Macrodantin in Sprague-Dawley rats

Chronic toxicity and oncogenicity studies of nitrofurantoin formulated as Macrodantin have been undertaken. The doses ranged from 12 to 116 mg/kg body weight/day. At 116 mg/kg/day, female rats showed a decreased weight gain. In the high-dose groups in the chronic toxicity study (males, 81 mg/kg/day; females, 116 mg/kg/day) there was an increase in testicular degeneration, sciatic nerve degeneration and fibrosis in both males and females, and an increase in focal biliary proliferation in females. There was no evidence of renal toxicity. There was no compound-related effect upon neoplasms at any site. In the oncogenicity study, an increase in focal biliary proliferation was observed in females given 31 or 56 mg/kg/day. There was no treatment-related increase in the incidence of neoplasms at any site. In particular there was no increase in the incidence of mammary or renal tumours. The observations in these studies indicate that therapeutic uses of Macrodantin would not present a carcinogenic hazard to man.

Cellular alterations preceding neoplasia in Pseudopleuronectes americanus from Boston Harbor

Dysplastic and neoplastic liver disease has been described in adult winter flounder from Boston Harbor. In this study we examined the pathogenesis of the disease. Early changes, in fish of 100–300 mm, included biliary proliferation, abnormal vacuolation of biliary pre-ductular epithelial cells and macrophage aggregation. The identification of biliary pre-ductular epithelial cells was based on nuclear morphology, numerous cellular junctions with adjacent hepatocyte apices, lack of contiguity with sinusoidal structures and central location in the hepatic tubule. Fish longer than 300 mm had progressively worsening pan-tubular changes in cholangiocytes and hepatocytes which culminated in grossly visible foci of vacuolation and associated neoplasia. Flounder from less contaminated sites showed occasional macrophage aggregations, but none of the other changes noted above. We suggest that the initial vacuolar change in Boston flounder occurs predominantly in pre-ductular cells, which may be stem cells, extending later to fill entire hepatic tubules and intrahepatic portions of the biliary system. The involvement of the vacuolation process in the development of neoplasia is a question we are currently addressing.

Time course of the intrahepatic lesion of extrahepatic biliary atresia: a morphometric study.

The time course of the intrahepatic lesions of untreated extrahepatic biliary atresia was evaluated by morphometric analysis of 49 specimens from 27 patients. The data show an early phase of rapid bile ductular proliferation, with peak in this material at 205 days, followed by rapid duct regression to approximately 400 days, and slower progressive intrahepatic duct loss thereafter. The ratio of ducts to connective tissue in portal tracts follows a similar course. Connective tissue in portal tracts rises on a slower course and continues to increase after maximum duct regression is reached, so the ratio of parenchyma to fibrous septa falls over the later course of the process. Although duct and connective tissue proliferation in hepatic portal tracts is associated in many liver diseases, the data of this study demonstrate dissociability of the relationships, with the fibrosis in the later stages of the intrahepatic process in extrahepatic biliary atresia apparently neither responsive to nor inducing biliary ductular proliferation.

Hepatic proline after bile duct ligation in rats.

Since biliary hyperplasia of fascioliasis correlated with hepatic proline level, we examined the occurrence of a similar chemical stimulus during bile obstruction. Uptake of tritiated proline and glycine rose in both hepatocytes and a bile duct enriched cell fraction, following duct ligation in rats. The increased hepatic content of proline but not glycine suggests that proline has a role in post-obstructive biliary proliferation.

Serum bile acid concentration in some experimental liver lesions of rat

The usefulness of measuring serum bile acid concentrations by RIA in a number of acute experimental liver injuries of rats was assessed by comparing the concentrations with the results of some of the routinely employed methods of examining hepatotoxic changes. Centribular liver cell injury produced by CCl 4 revealed leakage of GPT and GDH and to a lesser extent AP; along with minimal increase in serum bile acid levels. Serum bilirubin concentration remained unchanged. Surgical bile duct ligation resulted in marked rises in AP, GPT and GDH and total bilirubin levels and levels of serum bile acids. Intravenous injection of MnSO 4 induced focal necrosis of liver and bile canalicular dilation associated with elevated GDH and GPT concentrations. AP and bilirubin levels were unchanged. Bile acid levels were raised among female rats. 2,4-Xylidine induced hepatotoxicity revealed bile duct hyperplasia, liver cell enlargement, liver cell necrosis, biliary canalicular dilation and proliferation of endoplasmic reticulum. GDH and GPT levels were raised along with bile acid concentrations. This study suggested that assay of bile acid concentration is a sensitive indicator of several acute hepatic injuries.

The effect of maternal liver injury and dietary reduction on foetal growth in the rat

The effects on foetal growth of administering allyl formate or aflatoxin B 1 or of feeding a restricted diet to the pregnant rat have been studied. A significant retardation of foetal growth occurred in rats given allyl formate (0·15 ml/kg) by intubation on day 19 of pregnancy and in rats developing grade II liver lesions (extensive fatty infiltration, biliary proliferation and persistent cell necrosis) following similar administration of 5–7 mg aflatoxin B 1/kg on day 16. Paired-feeding experiments with untreated animals demonstrated that the reduction of foetal growth was related primarily to the dietary intake of the pregnant rat and only indirectly to the severity of the maternal liver lesion.

Lack of Effect of Dietary Chenodeoxycholic Acid on Plasma and Liver Lipids and the Ductular Cell Reaction in the Chick

Dietary lithocholic acid has been shown to induce a biliary proliferation or the ductular cell reaction in the chicken (Hunt et al., 1963), rabbit, guinea pig, rat, mouse (Hunt et al., 1964) and monkey (Hunt, 1965). This bile acid also elevates plasma lipids in the chicken (Leveille et al., 1963) and rabbit (Hunt et al., 1964).Holsti (1962) has reported that dietary chenodeoxycholic acid induces a hepatic biliary proliferation in the rabbit analogous to that seen with dietary lithocholic acid. It was therefore of interest to study the effects of chenodeoxycholic acid in the chicken since this species, like the rabbit, is extremely sensitive to dietary lithocholic acid; also, chenodeoxycholic acid has been reported to be a normal constituent of bile in the chicken (Anderson and Haslewood, 1957).Male Hy-Line White Leghorn chicks were fed a stock diet for one week and then received the basal diet previously described (Leveille…

Extraction of aflatoxin from rat liver.

It has been shown that a single dose of aflatoxin B1 given to a rat will result in acute liver damage1. Histologically the lesion, which is periportal in distribution, develops slowly as compared with either carbon tetrachloride2 or dimethylnitrosamine (DMN)3. Necrosis is first seen at 36–48 h. The liver parenchyma regenerates slowly and is accompanied by a biliary proliferation. After one month the liver still shows the biliary proliferation and also large hyperchromatic parenchymal cells.