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Tissue sections from four normal human thoracic ganglia were hybridized in situ with a varicella-zoster virus-RNA probe. Varicella-zoster virus was detected in two of four ganglia, localized exclusively in neurons. The detection of latent varicella-zoster virus genetic material in thoracic ganglia provides further evidence of varicella-zoster virus latency at multiple levels of the human neuraxis and supports the notion that the neuron is the primary site of herpesvirus latency.

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Human cataractous lens nuclei extract inhibited, in a dose-dependent fashion, [3H]ouabain binding to rat brain synaptosomes and microsomal Na+-and K+-dependent adenosine triphosphate (Na+ , K+-ATPase) activity and interacted with anti-digoxin antibodies. The compounds responsible for these activities, termed digitalis-like compounds (DLC), were also detected in bovine, rat, cat and rabbit, normal, transparent lenses, but the levels were only 0.7-5.4% of the average levels in the cataractous human lenses. DLC from the human cataractous lenses were purified by a procedure consisting of organic extractions and batch chromatography followed by filtration through a 3000 Da cut-off filter and subsequent separations using reverse-phase high-performance liquid chromatography. The presence of DLC in the different fractions obtained in the chromatograms was monitored by their ability to inhibit [3H]ouabain binding and Na+, K+-ATPase activity. Based on chemical ionization mass spectrometry together with ultraviolet spectrometry and biological characterization, it is suggested that new bufodienolides, 19-norbufalin and 19-norbufalin peptide derivatives are responsible for the endogenous DLC activity. It is proposed that these compounds may regulate Na+, K+-ATPase activity in the lens under some physiological and pathological conditions.The Na+-and K+-dependent adenosine triphosphate (Na+, K'-ATPase) is an integral plasma membrane protein responsible for the maintenance of Na+ and K' concentration gradients in all eukaryotic cells. Since Na+, K'-ATPase has a high-affinity receptor for digitalis steroids, it has been postulated that there are endogenous ligands for these receptors which regulate the Na+, K' pump activity. Indeed, based on their ability to inhibit ['Hlouabain binding and Na+, K+-ATPase activity, digitalis-like compounds (DLC) have been shown to be present in the brain [l-31, heart [4] [24]. However, none of these compounds appears to be the natural ligand of the digitalis receptor of the Na+, K+-ATPase because of their limited specificity and affinity. Bufodienolides, which resemble the structure of the plant cardiac glycosides, have been identified in the plasma, brain and other tissues of toads [14, 15, 25, 261, however, their

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