RESUMO
The interest in experimental use of coronary arteries of swine as a stage towards their application in human hearts justifies the need for obtaining a detailed anatomical understanding of those arteries, particularly to evaluate similarities and differences. However, we did not find any citations about anatomical indicators of coronary dominance among swine in the literature. Many authors have used the crux cordis and the origin of the posterior interventricular branch as references for defining three types of pattern in human hearts: right, balanced and left dominance. We used 30 hearts fixed in 10% formalin from male and female Landrace swine aged five to six months, weighing 80 to 110 kg. The branch corresponding to the subsinuosal interventricular sulcus came from the right coronary artery (96.7%) or from both coronary arteries (3.3%). The subsinuosal interventricular branch presented at least one small branch that went beyond the crux cordis. The apical area presented predominance of the paraconal interventricular (left anterior descending) branch in 43.3%, the subsinuosal interventricular branch in 23.3% and presence of both arteries in 33.3%. The left coronary artery emitted 54.5% of the ventricular branches and the right coronary artery 46.5%. Taking the crux cordis and the subsinuosal interventricular branch as references, the arterial pattern in swine hearts is right dominance. The diversity of the apical pattern and the balance in the distribution of ventricular branches do not allow this to be used as an approach in isolation. The similarities between human and swine hearts also apply to the coronary artery pattern.
Assuntos
Vasos Coronários/anatomia & histologia , Sus scrofa/anatomia & histologia , Animais , Circulação Coronária , Vasos Coronários/fisiologia , Feminino , Humanos , Masculino , Especificidade da EspécieRESUMO
The hepatitis B virus protein HBx has been implicated in the development of liver cancer. It has been shown that the HBx protein is able to bind to single-stranded DNA in a specific manner. This DNA binding activity might be relevant for HBx oncogene character. To study the HBx interaction with nucleic acids in more detail we expressed full-length HBx as well as several N- and C-terminally truncated HBx proteins as 6xHis and GST-fusions in E. coli. Using a gel shift assay, we were able to demonstrate that all of the truncated HBx proteins have the ability to bind to an AU-rich RNA. The affinity of GST-HBx #3 (residues 80-142) was an order of magnitude higher than that of GST-HBx #2 (residues 5-79), indicating that a high affinity RNA binding site is located in HBx C-terminal half. AUF1 is the protein ligand that binds to AU-rich RNA regions present in certain proto-oncogene mRNAs and causes their rapid degradation. By a competitive binding experiment of AUF1 and HBx to the AU-rich RNA oligonucleotide, we show that HBx is able to displace AUF1 from its binding site on the RNA oligonucleotide. This new aspect of HBx function is discussed in the context of cellular transformation.