Seven healthy adult dogs were used in this study. One was used as a
negative control. Three were subjected to high-velocity missile injury in
their left hind limb and considered as test animals. The other three were
subjected to low-velocity missile injury lacking high-pressure waves and
considered as positive controls. Small specimens of skeletal muscle were
taken from the diaphragm and the right fore limb (distant limb from the
shot site) ('fall animals for light and electron microscopic examinations.
Specimens of the high velocity injured animals showed abnormal
changes on electron microscopic examination in some muscle fibers as
widened spaces between myofibrils and myofilaments and oblique spaces
accompanied by disruption of sarcomeres. Also, distortion and irregularity
of Z lines, widening and breaking of sarcoplasmic reticulum and bursting
of some mitochondria were detected. These findings with normal
appearance on gross and light microscopic examination could be
attributed to the compression effect of the pressure waves accompanying
Tanta Medical Journal
452
high velocity missile injury. The absence of changes in the positive
control specimens on electron microscopic examination confirms the
suggested role of pressure waves. The more changes detected in the
diaphragm specimens in contrast to those seen in the right fore limb could
also be correlated to the distance from the site of injury. |
