Rapid decompression of congenital hydrocephalus associated with parenchymal hemorrhage.

A newborn boy with congenital hydrocephalus was diagnosed with aqueductal stenosis using magnetic resonance imaging. Low-resistance ventriculoperitoneal shunt placement was followed by clinical deterioration. Repeat imaging studies revealed a collapsed cortical mantle with subdural hemorrhage.

Implantation of PNS graft inhibits the induction of neuronal nitric oxide synthase and enhances the survival of spinal motoneurons following root avulsion.

In a spinal root injury model, our previous studies have shown that induction of nitric oxide synthase (NOS) appears only in spinal motoneurons of the root-avulsed segment in which significant motoneuron loss occurs but not in those of the distal root-axotomized segment (root axotomy 5-10 mm from the spinal cord) in which most motoneurons survive the injury. One hypothesis for the different response of motoneurons to root avulsion and distal root axotomy is that neurotrophic factors produced by the remaining peripheral nervous system (PNS) component are available for the distally axotomized motoneurons but are not available following avulsion. This hypothesis is tested in the present study by implantation of a PNS graft following the root avulsion.

Expression of c-jun and neuronal nitric oxide synthase in rat spinal motoneurons following axonal injury.

Expression of neuronal NOS, c-jun and c-fos in spinal motoneurons following axonal damage were investigated in the present study. Although either distal spinal root axotomy or root avulsion induced expression of c-jun, expression of c-jun was predominantly found in distal root-axotomized motoneurons. In contrast, expression of NOS was exclusively observed in avulsed motoneurons.

Neuronal nitric oxide synthase is induced in spinal neurons by traumatic injury.

Nitric oxide appears to mediate the immune functions of macrophages, the influence of endothelial cells on blood vessel relaxation, and also to serve as a neurotransmitter in the central and peripheral nervous system. Macrophage nitric oxide synthase is inducible with massive increases in new nitric oxide synthase protein synthesis following immune stimulation of macrophages. By contrast, endothelial nitric oxide synthase and neuronal nitric oxide synthase are thought to be constitutive with activation induced by calcium entry into cells in the absence of new protein synthesis.

Development of nitric oxide synthase expression in the superficial dorsal horn of the rat spinal cord.

Development of nitric oxide synthase (NOS) expression in the superficial dorsal horn of the rat spinal cord was studied using NADPH diaphorase histochemistry. At birth, no positive staining was seen in the superficial laminae of the cord. A week later, a few small positive neurons and fibers were seen in presumptive lamina II.