Duck hepatitis B virus infection, aflatoxin B1 and liver cancer in domestic Chinese ducks

Abstract

The oncogenicity of Duck hepatitis B virus (DHBV) is unclear since hepatocellular carcinomas (HCCs) have been reported only in domestic ducks in Qidong, an area of China where hepatitis B virus (HBV) and aflatoxin B1 (AFB1) are risk factors for liver cancer in man. In order to better define the association between DHBV infection, AFB1 and HCC we analysed a series of 16 duck liver samples collected from local farms in Qidong. HCC was found in eight and cirrhosis in one of these samples. Furthermore bile duct proliferation, characteristic of AFB1 exposure in ducks and other animal species, was found in these ducks. Integration of DHBV DNA into cellular DNA was observed in only one out of four DHBV positive HCCs, indicating that viral integration is not prerequisite for tumour development. In four remaining HCCs the polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in these ducks in the absence of DHBV infection. In addition, AFB1-DNA adducts were detected by hplc-immunoassay in one such DHBV-negative tumour. In summary we demonstrate that risk factors other than DHBV, including AFB1 exposure, may be important in duck liver carcinogenesis in Qidong. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Reduction of toxic effects of aflatoxin B1 by using baker yeast (Saccharomyces cerevisiae) in growing broiler chicks diets

“…In the present investigation, the data from the results demonstrated that dietary aflatoxin significantly lowers the feed intake and body weight of the birds. Similar results has been reported by Cova et al (1994). Sell et al (1998), studying ducks, had similarly reported decreased feed intake and lower body weight.…”

Acute Liver Injury Following Infection With A Cytopathic Strain of Duck Hepatitis B Virus

“…Periportal cell proliferation is a well-documented response of the duck liver to injury by the hepatotoxin, aflatoxin B 1 . [18][19][20] At day 9, the bile ductulelike cells were organized into cords and ductular networks that had greatly regressed in their prominence by 23 days' postinfection. It is possible that these small cells contributed to the restoration of normal hepatic architecture observed by day 23 postinfection by providing a source of newly differentiated hepatocytes to the injured liver.…”

Sequence-specific inhibition of duck hepatitis B virus reverse transcription by peptide nucleic acids (PNA)

“…In addition, DNA was extracted from DHBV positive duck serum and used as control for input viral DNA migration. The DNAs (5 mg) were analyzed by Southern blot using a 32 P-labelled DHBV probe as described previously [38,39]. Viral DNA was quantified by PhosphorImager using ImageQuant software (Molecular Dynamics).…”