Antisense approaches for elucidating ranavirus gene function in an infected fish cell line.

Viral virulence/immune evasion strategies and host anti-viral responses represent different sides of the continuing struggle between virus and host survival. To identify virus-encoding molecules whose function is to subvert or blunt host immune responses, we have adapted anti-sense approaches to knock down the expression of specific viral gene products. Our intention is to correlate knock down with loss of function and thus infer the role of a given viral gene. As a starting point in this process we have targeted several structural and catalytic genes using antisense morpholino oligonucleotides (asMO) and small, interfering RNAs (siRNA). In proof of concept experiments we show the feasibility of this approach and describe recent work targeting five frog virus 3 genes. Our results indicate that both 46K and 32R, two immediate-early viral proteins, are essential for replication in vitro, and confirm earlier findings that the major capsid protein, the largest subunit of the viral homolog of RNA polymerase II, and the viral DNA methyltransferase are also essential for replication in cell culture.

Histamine receptors in urethrovesical smooth muscle.

Through the method of pharmacologic antagonism, the contractile effect of histamine was studied simultaneously on isolated smooth muscle preparations obtained from the body and base of the bladder and from the proximal urethra of the guinea pig. Histamine had a contractile effect mediated specifically through H1 receptors, with no H2 activity. This effect was most marked in the body of the bladder, comparatively moderate in the base, and slight in the proximal urethra. It appears that histamine effect is not mediated through either a cholinergic or an adrenergic mechanism. Clinical implications are discussed.