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Biomedical subjects

R Morecki

Publications and source records attributed to R Morecki.

45 records · Page 3Linked to original sources

Idiopathic neonatal iron storage involving the liver, pancreas, heart, and endocrine and exocrine glands.

Autopsy studies of two infants, one a newborn, the other 4 months old, revealed massive amounts of iron in lysosomes of hepatocytes and pancreatic acinar cells. Iron, which had been transported across the placenta, accumulated in the same cell types as in adults with primary and secondary hemochromatosis. Hemosiderin was found in cardiac muscle cells, gastric and intestinal glands, and endocrine and exocrine organs including pituitary, thyroid, adrenals, islets of Langerhans, and sublingual and sweat glands. The liver was the most affected organ and the normal hepatic architecture was replaced by hepatocytes which were arranged in cluster, pseudoacinar structures, and multinucleated giant cells embedded in a collagen matrix. The islets of Langerhans were hyperplastic and hypertrophic. Ten similar cases, in five families, have been described; no patients liver longer than 4 months. Neonatal iron storage disease is clinically and pathologically distinct from Zellweger's cerebrohepatorenal syndrome and hypermethioninemia (tyrosinemia) neonatal diseases in which large stores of iron are present in hepatocytes. No abnormalities in serum iron, ferritin, or transferrin concentrations were detected in five parents of the affected children.

Cytoplasmic Granules↗

Extrahepatic biliary atresia in a rhesus monkey (Macaca mulatta).

Extrahepatic biliary atresia was observed in a 6-week-old female rhesus monkey. Jaundice and conjugated hyperbilirubinemia were detected at the age of 6 days and persisted throughout life. At 6 weeks of age, the diagnosis of extrahepatic biliary atresia was established at exploratory laparotomy, and bile duct remnants were biopsied. Histological examination of these specimens showed inflammatory and fibrosing lesions similar to those observed in humans with extrahepatic biliary atresia. Because of serologic evidence of Reovirus 3 infection in human patients with extrahepatic biliary atresia, serum of the affected monkey was tested for antibodies to this virus. Three sequential serum samples obtained during the course of illness showed persistently high Reovirus 3 titers which are consistent with but do not prove concurrent Reovirus 3 infection. This report represents the first documented case of spontaneous extrahepatic biliary atresia in a nonhuman primate and suggests that this species may be suitable for further investigation of the pathogenesis of this disease.

Animals↗

Detection of reovirus type 3 in the porta hepatis of an infant with extrahepatic biliary atresia: ultrastructural and immunocytochemical study.

This report describes immunocytochemical and ultrastructural methods which led to the identification of Reovirus type 3 (Reo-3) in the porta hepatis of a patient with extrahepatic biliary atresia. The study indicates that Reo-3 antigenic sites are demonstrable by the avidin-biotinylated complex peroxidase method following formalin fixation and paraffin embedding, but are destroyed by freezing and thawing prior to fixation. Deparaffinization of the block and subsequent rembedding in epon-araldite did not alter immunoperoxidase staining. This procedure offered the advantage of higher light microscopic resolution of semithin (1 micron) sections and assisted in the selection of specific areas for ultrastructural studies. Localization of Reo-3 in extrahepatic biliary atresia was confined to a biliary remnant in which there were acutely inflammed, partially necrotic microscopic ducts. Electron microscopic examination of the immunoreactive sites revealed virus-like particles similar in appearance to Reo-3 particles in infected tissue culture cells. The observations presented here support previously reported serologic data which have shown an association between Reo-3 infection and extrahepatic biliary atresia.

Animals↗

An extrahepatic bile duct growth factor: in vivo effect and preliminary characterization.

Rabbit sera injected intraperitoneally into BALB/c mice were noted to produce a considerable and selective enlargement of extrahepatic bile ducts. The gallbladder, intrahepatic ducts, liver and other organs showed no stimulation of growth. Duct enlargement leading to widening of its outer diameter which, on average, was 3.6 times that of normal, was due entirely to an increased number of epithelial cells with prominent proliferation of intramural glandular components. There was no evidence of inflammatory bile duct injury, fibrosis or obstruction. All of the above changes were reversible and regressed slowly after discontinuation of injections. The bile duct growth-promoting factor was detected in sera of many animal species including humans and birds. Host response to this factor was determined by the number of injections and appeared to be strain-related since it was not observed in C57BL or C3H mice. The sex and age of the donor or recipient were not of any relevance to the growth response. In order to isolate and characterize the bile duct growth factor, rabbit serum was separated into various fractions, and the effect of each fraction was tested in the animal model. Proteins in the 33 to 65% ammonium sulfate precipitate of whole rabbit sera had activity equal to that of native sera. Activity was abolished by treating this serum fraction with 1% sodium dodecyl sulfate plus proteinase K, suggesting that the bile duct growth factor is a protein. Lipids extracted from whole sera using chloroform: methanol or ultracentrifugation were devoid of activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗