Pattern of expression of gamma-glutamyl transpeptidase in rat liver and kidney during development: study by immunochemistry and in situ hybridization.

We used an in situ hybridization technique using single-stranded RNA probes to study the expression pattern of gamma-glutamyl transpeptidase (GGT) in rat liver and kidney during development. The results were compared to those obtained with an immunoperoxidase technique and with Northern blot analysis of GGT mRNA. In the kidney, northern blot revealed a 20-fold increase of GGT mRNA between day 18 of gestation and adulthood. Protein and mRNA localization clearly identified the proximal tubules as the site of synthesis of GGT. In the liver, the expression was lower than in the kidney and Northern blot showed a dramatic decrease of expression after birth. Using immunohistochemistry, the protein was detected within parenchymal cells in embryo and hepatocyte membranes and bile ducts in adults. Using in situ hybridization, GGT mRNA was only detected on days 1 and 2 after birth and exclusively in hepatocytes. Immunoperoxidase may be more sensitive than in situ hybridization to study the expression of minor liver protein such as GGT. However, the study of GGT expression using in situ hybridization is possible in cases of increased expression such as alcoholism, cholestasis, and carcinogenesis.

Interstitial deletion of the short arm of chromosome 20 in arteriohepatic dysplasia (Alagille syndrome).

An autosomal dominant transmission of arteriohepatic dysplasia, or Alagille syndrome, with reduced penetrance and variable expressivity has been suggested from familial pedigrees, but the nature of the genetic defect and its chromosomal localization are not firmly established. We report the case of an 8-year-old boy with arteriohepatic dysplasia, in whom high-resolution chromosome study showed a partial deletion of the short arm of chromosome 20, which encompasses subbands p11.23 to p12.3. In situ hybridization and Southern blotting localized four restriction fragment length polymorphism probes within the deletion and another one distal to the deletion. Because one patient has already been reported to have arteriohepatic dysplasia and deletion of the short arm of chromosome 20, and six additional patients with such a deletion had major features of Alagille syndrome, this syndrome should now be assigned to chromosome 20p.

Detection of mononuclear cells expressing hepatitis B virus in peripheral blood from HBsAg positive and negative patients by in situ hybridisation.

In situ hybridisation was used to detect RNA of Hepatitis B virus (HBV) in peripheral mononuclear blood cells. Presence of HBV-RNA was detected in 10/17 HBsAg positive HBeAg positive patients, in 8/18 HBsAg positive HBeAg negative patients, in 1/3 anti-HBs positive subjects. Four control subjects were negative. The frequency of labelled cells varied from 1 to 10% of mononuclear cells. These results indicate that the DNA detected so far in mononuclear blood cells may be transcriptionally active.

Immunoglobulin deposits in the biliary remnants of extrahepatic biliary atresia: a study by immunoperoxidase staining in 128 infants.

Bile duct remnants taken from 128 infants during surgery for extrahepatic biliary atresia were paraffin embedded prior to immunoperoxidase staining. Immunoglobulin deposits were found in 44 remnants. They were made up of IgM alone in 25 cases and of IgM and IgG in 19. Deposits were observed along the basement membranes of glandular structures. These findings suggest that extrahepatic biliary atresia might be an acquired and evolving disease.

Reduced ratio of portal tracts to paucity of intrahepatic bile ducts.

The syndrome of "paucity" of intrahepatic bile ducts is characterized by a reduction of the ratio of interlobular bile ducts to portal areas. The present unidirectional study of liver biopsy specimens in cases of so-called intrahepatic biliary atresia, controlled essentially by age-matched autopsy control, showed that there is also a reduced number of portal areas in the livers of these subjects. This fact suggests an injury to the vascular anlage associated with biliary injury.

An animal model for the study of human alpha-1-antitrypsin deficiency.

Turkeys with "round heart disease" often have a deficiency in alpha1 globulin. Within their liver cells, PAS +, diastase resistant granules are present, and are remarkably similar to those of persons with inherited AAT deficiency. The electrophoretic patterns made according Fagerhol's method showed differences between the serum of healthy birds and the turkeys suffering from "round heart disease".