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D Biermanns

Publications and source records attributed to D Biermanns.

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Progress in developing animal models for biliary atresia.

Animal models for extrahepatic biliary atresia (EHBA) have failed to simulate the course of the disease. Until now only a few aspects of the entity could be investigated and no model was helpful in discovering the etiology of EHBA. Following the suspicion of a viral and hepatotropic infection, investigations in an infectious mouse model were continued. The results of previous and topical studies are summarized here. Infection of newborn Balb/c-mice with rhesus rotavirus (RRV) leads to cholestasis in 85% of the animals followed by a lethality of 90%. Preparation and histomorphological investigation of liver and ligamentum duodenale reveal EHBA of varying extent. Clinical course and morphological findings in mice are very similar to EHBA in newborn children and the results are presented in a chronological table. Hepatobiliary morbidity and lethality after RRV infection is higher in Balb/c-mice than in other mouse strains. This observation supports the suspicion that immunocompetence might be a determining factor in the etiology of EHBA. Initial therapeutic trials were made using this model by treating infected newborn mice with interferon-alpha (IFN). The prophylactic application of IFN protects the infected mice from cholestatic symptoms and appears to induce partial immunity. Their descendants are protected against the hepatotropic effect of RRV infection. Infected animals presenting with clinical signs of cholestasis can be treated successfully by IFN-therapy for one week. In the presented animal model. EHBA can be better induced and simulated than by any other method. As a first trial, a non-surgical and more etiologically orientated therapeutic method is tested in this model.

Animals↗

New aspects in a murine model for extrahepatic biliary atresia.

The cause of extrahepatic biliary atresia (EHBA) remains unknown, and even an animal model is still lacking. Observations in a murine infectious model (newborn Balb/c mice infected with rhesus rotavirus group A [RRV]) reported extrahepatic biliary obstruction similar to findings in children who have EHBA. In the present study, this animal experiment was repeated, and the clinical and histomorphologic changes were observed over 3 weeks. Eighty-nine newborn mice were infected with RRV, and 67% showed signs of cholestasis and delayed growth. Eight of these animals recovered spontaneously whereas the others remained icteric. Fourty-six pups were prepared for microscopic examination following a 2-day interval. From the fifth day, the whole biliary tract showed edematous swelling with cellular infiltration. Ten days later, in the extrahepatic bile duct, a transformation took place in which concentric infiltration led to complete obstruction, sometimes with prestenotic dilatation. The intrahepatic changes showed reactive necrosis and proliferation of the small bile ducts. In one 19-day-old mouse, a ballooning dilatation was observed, similar to a developing choledochal cyst. Infection with RRV induces in newborn Balb/c mice a cholestatic clinical picture with different courses of the disease leading mostly to complete biliary obstruction and secondary hepatic changes similar to EHBA in children. This is the first animal model for EHBA with complete obstruction of the extrahepatic bile duct induced by infection. These findings present a new basis for further studies.

Animals↗