| 1. BackgroundTraumatic neuroma will inevitably occur postinjury and Cravioto holds that obstinate and unbearable pain exists in about ten percent patients. No effective treatment has been available by far due to the ignorance of its true molecular pathophysiological mechanism. At the same time, it is clear that several kinds of neurotrophic factors are concerned with the survival of neurons and the regeneration of axons post nerve injuries. Thus, it is important to make sure whether some kinds of nerve grow factor and its receptors are indeed related to the formation of traumatic neuroma in the special condition that nerve regeneration and degeneration are concomitant.2. Objective(1) To observe the expression and distribution of alpha-smooth muscle actin( a -SMA) in the traumatic neuroma and discuss its significance and relationship with traumatic-neuroma pain.(2) To observe the expression and distribution of nerve growth factor and its low affinity receptor(p75) in the traumatic neuroma and discuss its significance and relationship with the growth of peripheral nerve and the formation of the traumatic neuroma.3. MethodsForty-two cases of traumatic neuroma were collected with the progress fromhalf to eighty-four months (average 3.9 months), and divided into asymptomatic group(n=31), symptomatic group(n=ll); and according to its course , The cases were also divided into four groups, ie, group I (less than one month), group II (1-3 months), group III (3-6 months) and group IV (more than six months). Fifteen cases of normal nerve samples were harvested as the control group(n=15). Immunohistochemical studies were performed to observe the expression of a -SMA,NGF and p75. Their expression levels were detected respectively by the computer graph analysis system. 4. Results(1) There was no significant expression of a -SMA in the control group and asymptomatic group(no significance between them,Q=0.36 P>0.05) except for the positive reaction in the smooth muscle cells of the small vascular walls, while in the symptomatic group significant expression of a -SMA was observed besides the expression in the smooth muscle cells of the small blood vessels, and the positive fields were mainly located in the cellular plasm. The positive fields were diffusely distributed between the proliferous nerve fibers and collagen tissues most of which showed the streak or linear shapes together with some dot-like expression figures. The difference of the expression level among the three groups was significant(F=289.534, PO.01) and q-test showed that the difference between the asymptomatic group and symptomatic group or the control group was significant (Q=6.87, PO.01; Q=7.44,P<0.01).But there were no significant difference between ehe control group and the asymptomatic group(Q=0.36, P>0.05). Correlation analysis indicated that the expression level of a -SMA was positively correlated with the scale of the pain assessed by means of a 10-point visual analogue scale (VAS) (rs =0.980,/?<0.001) and the linear regression equation was Y=648.498 X -298.261 (P =0.000) .(2) There was no significant expression of NGF and p75 in the normal nerve while in the four studied groups, significant expression of NGFand p75 were all observed. NGF was detected in the early stage of the traumatic neuroma (from two weeks or even earlier) and achieved its peak in about 3-4 months time and became less in about six months. The level of p75 was weak in the early time and achieved its peak in three months, but the high level state was maintained even after six months. The one-way Anova statistic analysis manifests that there were no significant differences of the expression of NGF among the prior three groups (P>0.05} but each compared with the group IV and between themselves, the differences were significant (P<0. 05) ; there were no significant differences of the expression of p75 among the group II, III and IV (P>0.05), but the differences among the group I and the latter three groups were significant (P |
PDF Full Text Request