The cellular changes that take place as the intestinal cell migrates from crypt to villus are morphologically and biochemically remarkable. It is fortunate that many of these phenomena can be delineated by following enzymic activities. Sucrase-isomaltase is a particularly fascinating enzyme complex because it is a marker of the differentiated cell. Sucrase is inducible with steroids and protected by the substrate sucrose. Purified enzyme can be used to stimulate production of specific antibodies in goats; these antibodies have been used as probes to locate enzymically active and inactive antigen in the cells of the crypt and villus respectively. Further examination of the enzyme has indicated a molecular weight of 200 000--350 000. These higher molecular weight components are located in the brush border of the enterocytes. Lower molecular weight subunits are antigenically active and are in the cytosol. It is assumed that these smaller components are enzymically inactive pre-combination subunits of the sucrase-isomaltase complex and that the sucrase-isomaltase of the brush border is an aggregate of these subunits. The California sea lion, which is deficient in intestinal sucrase activity, does have isomaltase activity. This finding supports the concept that there are different gene complexes for sucrase and for isomaltase.

Aging↗

PubMedDate not supplied

Orthotopic liver transplantation: a pathological study of 63 serial liver biopsies from 17 patients with special reference to the diagnostic features and natural history of rejection.

The histopathological features of orthotopic liver transplants were evaluated in 63 serial biopsy specimens from 17 patients. Biopsies were taken at the time of insertion of the liver (six biopsies), at the time of development of liver function abnormalities (11 biopsies) and as follow-up to previously abnormal biopsies (46 biopsies). The biopsies taken at the time of insertion all showed diffuse hepatocellular ballooning with confluent areas of necrosis in one case. Biopsies taken at the time of onset of rejection (nine cases) all showed a mixed portal inflammatory infiltrate, bile duct damage and central or portal vein endothelialitis (i.e., attachment of lymphocytes to the vein endothelium). Follow-up biopsies showed several patterns including: (i) resolution of changes of acute rejection with subsequent development of recurrent acute or chronic rejection (four cases); (ii) prolonged acute rejection simulating extrahepatic biliary obstruction (four cases); (iii) prolonged acute rejection with predominance of eosinophils simulating a drug reaction (one case); and (iv) rapidly progressive acute rejection leading to death (one case). Biopsy of the transplanted liver at the time of transplantation is useful to provide a baseline for comparison with later biopsies. Biopsy at the time of onset of changes in liver function is essential to confirm the presence of rejection prior to alteration of immunosuppression.

Adolescent↗

PubMedDate not supplied

The liver in Crigler-Najjar syndrome, protoporphyria, and other metabolic disorders.

The liver may be involved in metabolic disorders in two ways. (i) Due to its critical role in several metabolic pathways, the liver may be the major site of expression of a biochemical abnormality. For example, in Type I Crigler-Najjar syndrome, absence of hepatic bilirubin glucuronyl transferase activity causes severe unconjugated hyperbilirubinemia which invariably leads to death from kernicterus. (ii) The liver may also be structurally damaged by the metabolic disorder. Several patients with protoporphyria have died in hepatic failure due to liver damage caused by protoporphyrin deposition. Numerous other metabolic disorders can be sited in which significant liver involvement occurs. In many of these disorders, there is no effective medical therapy.

Animals↗

PubMedDate not supplied

Hepatic alpha 1-antitrypsin mRNA content in cirrhosis with normal and abnormal protease inhibitor phenotypes.

We quantitated alpha 1-antitrypsin mRNA in normal, alpha 1-antitrypsin-deficient cirrhotic and biliary cirrhotic livers using two-dimensional electrophoretograms of [35S]methionine-labeled translational products of total hepatic RNA and RNA/DNA hybridization. alpha 1-Antitrypsin precursor product was identified by immunoprecipitation. The relative abundance of alpha 1-antitrypsin product from normal (0.989 +/- 0.197), cirrhotic (0.956 +/- 0.062) and alpha 1-antitrypsin deficient (0.818 +/- 0.12) livers was not significantly different. Although (RNA/DNA) was decreased in the PiZZ cirrhotic livers compared to normal (0.56 +/- 0.045 vs. 0.95 +/- 0.225), it equaled that found in the PiM cirrhotic livers (0.56 +/- 0.055). The concentration of alpha 1-antitrypsin mRNA [relative abundance X (RNA/DNA)], while decreased in PiZZ compared to normal liver, is thus no different in PiZZ cirrhotics than in PiM cirrhotics. We confirmed this observation by quantitation of the alpha 1-antitrypsin mRNA using an alpha 1-antitrypsin genomic probe. By RNA/DNA hybridization, alpha 1-antitrypsin mRNA was equal in PiM cirrhotic and PiZZ cirrhotic (38.48 +/- 4.5 vs. 31.93 +/- 2.1), but significantly decreased from noncirrhotic PiM liver (58.36 +/- 12.7). We conclude that alpha 1-antitrypsin mRNA is decreased in cirrhosis of any etiology, and this decrease appears to represent a general response of the liver to injury. Since the decreased alpha 1-antitrypsin mRNA in PiM cirrhotics is associated with normal serum alpha 1-antitrypsin levels, it is unlikely that the decreased alpha 1-antitrypsin mRNA in PiZZ cirrhotics accounts for their decreased serum levels.

Adult↗

PubMedDate not supplied

What is "primary sclerosing cholangitis"?

Explore the source record for details and available documents.

Antibodies, Antinuclear↗