A quantitative assessment of the density of the protein gene product 9.5 (PGP9.5), the neural cell adhesion molecule (NCAM), and the low-affinity nerve growth factor receptor (NGFR) expressing nerve fibers in the circular muscle layer in the colon was carried out by morphometric analyses from 13 patients with Hirschsprung's disease (HD). The difference in the nerve fiber density between the ganglionic and aganglionic segments was compared by calculating the ratio of the sum of the areas occupied by positively stained nerve fibers per unit area of the muscle after immunohistochemical staining on paraffin embedded tissue sections using computer software. There was an obvious difference in the density of the PGP9.5 stained nerve fibers between the ganglionic (0.0380 +/- 0.0171) and aganglionic segments (0.0143 +/- 0.01661). The NCAM-positive nerve fibers were fewer in number than those of both the PGP9.5-positive fibers and NCAM-positive fibers, which were also markedly lower in number in the aganglionic segment (0.0066 +/- 0.0076) than in the ganglionic segment (0.0230 +/- 0.0195). Immunostaining for low-affinity NGFR revealed much fainter staining in the ganglionic and aganglionic segment without a statistically significant difference in their density. Considering the fact that PGP9.5 is a very sensitive marker for nerve fibers, the results of this study reaffirm the innervation failure of the proper muscle in HD. The decreased NCAM expression level in the aganglionic segment appears to be caused not by the selective down-regulation of NCAM expression among the nerve fibers but by a markedly reduced number of nerve fibers.
Colon/*innervation ; Hirschsprung Disease/*pathology ; Human ; Muscle, Smooth/*innervation ; Nerve Fibers/*chemistry/pathology ; Neural Cell Adhesion Molecules/*analysis ; Receptor, Nerve Growth Factor/analysis ; Thiolester Hydrolases/*analysis

OBJECTIVETo determine the changes of Substance P in the substantia gelatinosa of the dorsal horn field after transient liquid nitrogen freezing of severed rat sciatic nerve for prevention of terminal neuroma.

METHODSThe bilateral sciatic nerves of 20 SD rats were severed, and the left sciatic nerves was subjected to transient liquid nitrogen freezing with the right sciatic nerve as control. After 20 and 28 weeks, the nerve ends were resected and prepared for microscopic examination, and Substance P in the substantia gelatinosa of the dorsal horn field was determined by immunohistochemistry.

RESULTSTypical neuromas occurred in the severed ends of the right sciatic nerves but not in the left sciatic nerves. The distribution and optical density of Substance P in the substantia gelatinosa of the dorsal horn field was significantly smaller in the left than in the right nerves (P<0.05).

CONCLUSIONLiquid nitrogen freezing of the severed sciatic nerve results in decreased release of Substance P in the substantia gelatinosa of the dorsal horn field, suggesting that noxious stimulation may increase Substance P release in the substantia gelatinosa of the dorsal horn field.

Animals ; Cryopreservation ; methods ; Female ; Male ; Nerve Fibers ; metabolism ; pathology ; Neuroma ; metabolism ; pathology ; prevention & control ; Nitrogen ; chemistry ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; metabolism ; pathology ; Substance P ; metabolism ; Substantia Gelatinosa ; metabolism ; pathology

OBJECTIVETo study the effect of traumatic occlusion on CGRP-immunoreactive (CGRP-IR) nerve fibres in rat molar pulp and observe the recovery of CGRP-IR nerve fibres after removal of traumatic occlusion.

METHODSTo observe immunohistochemically the change of CGRP-IR nerve fibres in molar pulp during traumatic occlusion and after removal.

RESULTSThe increase of number, density and morphology of CGRP-IR nerve fibres in traumatic occlusion group was more than in control group, however, the changes of CGRP-IR nerve fibres in removal of traumatic occlusion group were less than in control group.

CONCLUSIONSThe changes of CGRP-IR nerve fibres in number, morphology, and density are induced by traumatic occlusion in rat molar pulp, however, the nerve fibres recover to normal by removal of traumatic occlusion.

Animals ; Calcitonin Gene-Related Peptide ; analysis ; Dental Occlusion, Traumatic ; metabolism ; pathology ; therapy ; Dental Pulp ; innervation ; Immunohistochemistry ; Male ; Molar ; innervation ; Nerve Fibers ; chemistry ; Rats ; Rats, Sprague-Dawley