Nitric Oxide: Perspectives and Emerging Studies of a Well Known Cytotoxin

The free radical nitric oxide (NO•) is known to play a dual role in human physiology and pathophysiology. At low levels, NO• can protect cells; however, at higher levels, NO• is a known cytotoxin, having been implicated in tumor angiogenesis and progression. While the majority of research devoted to understanding the role of NO• in cancer has to date been tissue-specific, we herein review underlying commonalities of NO• which may well exist among tumors arising from a variety of different sites. We also discuss the role of NO• in human physiology and pathophysiology, including the very important relationship between NO• and the glutathione-transferases, a class of protective enzymes involved in cellular protection. The emerging role of NO• in three main areas of epigenetics—DNA methylation, microRNAs, and histone modifications—is then discussed. Finally, we describe the recent development of a model cell line system in which human tumor cell lines were adapted to high NO• (HNO) levels. We anticipate that these HNO cell lines will serve as a useful tool in the ongoing efforts to better understand the role of NO• in cancer

Photoresponsiveness of Aplysia Eye is Modulated by the Ocular Circadian Pacemaker and Serotonin

Volume: 180Start Page: 284End Page: 29

Synaptic Connections between a Transplanted Insect Ganglion and Muscles of the Host

When a metathoracic ganglion from one cockroach (Periplaneta americana) is transplanted into the coxa of another cockroach, it innervates only those leg muscles that have been previously denervated. The transplanted ganglion evokes hyperpolarizing synaptic potentials in the host muscles that it innervates. These potentials are correlated with twitching of the host limb

Nerve Regeneration: Correlation of Electrical, Histological, and Behavioral Events

Wihtin 5 days after the leg nerves of a cockroach are injured, miniature end-plate potentials have disappeared. and the muscle is unresponsive to electrical stimulation. The soma of the injured neutron has a dense perinuclear ring of RNA. By 40 days after the injury, locomotor activity has returned, and the miniature end-plate potentials and evoked electrical responses have reappeared in the muscle. The RNA ring has disappeared, and the nucleus of the regenerating neuron has shifted to an eccentric position