ABSTRACT
<p><b>OBJECTIVE</b>To explore an early stage repair method for soft tissue defect of limbs of modern firearm wound, and to improve treating result.</p><p><b>METHODS</b>Defects of the hind limbs of dogs were repaired with skin, muscle and myocutaneous flaps.</p><p><b>RESULTS</b>Wounds healed within 2 weeks in the experimental group except one that healed in 3 weeks because of infection. Limb function was close to normal. The treatment result was better in the experimental group than the control.</p><p><b>CONCLUSIONS</b>Skin, muscle and myocutaneous flaps can cover soft tissue defect at an early stage, prevent and reduce infection, promote the healing and recovery of combined injury, reduce the time of treatment and disability rate.</p>
Subject(s)
Animals , Dogs , Debridement , Hindlimb , Wounds and Injuries , Microsurgery , Soft Tissue Injuries , General Surgery , Wound Healing , Wounds, Gunshot , General SurgeryABSTRACT
To investigate the temporal variation of cell-mediated immunity in injured tissue of maxillofacial firearm trauma. Cells expressing messenger RNA(mRNA) for IL-2 were demonstrated by dot blotting and in situ hybrization in injured tissue of maxillofacial trauma inflicted by bullet, in conjunction with immunohistochemistry for IL-2 in normal and postinjury conditions. It was found that, apart from a transient eleratim in level within 24h post injury, both IL-2 production and IL-2 mRNA expression were consistently suppressed in cells at the site of the wound compared with the normal. The changes in the tissues of indirect injury by the projectile were significant. These results indicate that the cell-mediated immunity was suppressed in maxillofacial firearm trauma and the principal cellular abnormalities that resulted in altered T cell activation and IL-2 production postinjury was downregulation of mRNA before IL-2 gene transcription. It also suggested that the indirect injury by projectile contribute mainly to the depression of cell-mediated immunity.
ABSTRACT
Objective: To investigate the expression changes of TNF ? mRNA after brain explosive injury in dogs. Methods: With the brain explosive injury model we had developed, nuclei acid in situ hybridization with an antisense RNA probe and computer image analysis were used to detect the dynamic changes of TNF ? mRNA in the cerebral cortex, hippocampus, hypothalamus, and up brain stem after brain injury. Results: The expression of TNF ? mRNA could be found in several regions of normal dog's brain tissues, and the expression became more obvious and widespread following explosive injury to the brain. In all of the brain regions, the expression changes of cerebral contussive area and hippocampus were more significant. TNF ? mRNA expression increased significantly at 30 min and reached maximum at 1 h after the explosive injury, and then decreased gradually, which was higher than normal's. More expression were detected in the ipsilateral hemisphere than contralateral hemisphere. Conclusion: The expression of TNF ? mRNA in basal condition implicate that TNF ? may play an important role in neural function. It is suggested that TNF ? may play an important role in traumatic brain injury. [
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The morphological and pathophysiological manifestations of theheart after abdominal gun-shot wound created by a model-53 smooth bore gun of 6.35 mm in caliber with 1.03 g steel ball were observed in 15 pigs,which were randomized into 3 groups.Five animals of the first group were killed immediately after wounding and all the animals showed small spotty flat hemorrhages on the endocardium of the left ventricle under gross inspection.Focal or small flat hemorrhages on the myocardium and under the endocardium were found under optical microscopy.Under electron microscopy,myofibrilla gaps were widened and filled with fluid,and mitochondrial swelling or vacuolar degeneration in the myocardium could be seen.7 animals of the second group were infused and monitored until they were killed 72 hours after wounding.It was found that there were varying degrees of functional disorder of the left ventricle in every animal.The serum level of creatine kinase isozyme MB increased significantly.The 3 pigs of the third group were killed with large andrapid blood-shedding without gun-shot wound and showed no similar pathological changes.
ABSTRACT
The injurious changes of the microvasculature in the maxillofacial region due to high-velocity bullet injury were observed in different time intervals with scanning and transmission electron microscopy. It was found that there were microthrombus formation in the vascular lumen, and endothelial loss and dege-neration or necrosis of the vascular wall in the microvasulature around the wound. Our findings indicate that when early reconstructive surgery for the tissue defect due to gunshot wound especially for those in the maxillofacial region is to be performed with microsurgical technique, it is essential for the surgeon to realize and consider the wounding condition on the microvasculature of the recipient site.
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Through the experiments of producing spherical steel-bullet (4.763mm in caliber and 0,44gm in weight) wound on the hind legs of 17 dogs, the authors re- ported that there was a definite linear relationship between the reactions of the serum creatine kinase and the amount of kintic energy from the high speed of the bullets absorbed by the tissues and also with the weight of dead tissue removed around the bullet-path, Within the first 6 hours after injury, the activity of SCK increased with the rise of the biologic effect values of the amount of the kinetic energy absorbed and the weight of the dead tissue removed.
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The processes of temporary cavitations produced with 7.62mm bullet, 5.56 mm bullet and 6.35mm spherical steel-pellet in water were recorded with a high speed (8,000 frames per second) camera to investigate the traumatic mechanism of fragments with high velocity and small mass. The temporary cavities produced with above mentioned projectiles were different because of their different ballistic behaviors. The shape and size of the temporary cavitv and the time of its formation were closely related to the density of the adjacent tissues and also to the extent of the tissue damage. Thus the study on the temporary cavitations after projectiles of high velocity but small mass is of clinical significance.
ABSTRACT
Histopathological and ultrastructural changes of the lungs were observed in various intervals after high-velocity bullet wounds of the two thighs of dogs. It was found that histologically there were microvascular dilatation, congestion, capillary rupture, interstitial and alveolar bleeding, focal atelecta-sis and pulmonary emphysema in the first half hour and the 6th hour after injury. In addition, microvascular embolism and hyaline membrane formation were seen in the 24th and 72nd hour after injury. Under electron microscopy, there were swelling of capillary endothelium, swelling, degeneration and necrosis of type I pneumocytes, shortening and decreasing of the microvilli of type II pneu-mocytes, significant vacuolation of the lamonar bodies, accumulation of leucocytes and platelets in the capillary lumen,and obvious decrease of the granules in the leucocytes. The mechanism of the pulmonary injury accompanying bullet wound of the thighs was discussed.
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The pressure changes in water and in 20% gelatin blocks produced by bullets of 7.62 mm and 5.56 mm calibre and spherical steel balls of 1.03gm were studied. The pressure was measured by the BJ-100 model transducer.It was demonstrated that there were three peak waves produced when the two kinds of bullets were fired through a water tank. The interval between the two peaks was longer in the waves produced by 7.62mm bullet than in those produced by 5.56mm bullet, the value of The pressure due to 5.56mm bullet was the largest, that due to 7.62mm bullet was the second, and that due to the spherical steel ball was the lowest.The fore-mentioned differences among the pressures produced by different projectiles were closely related to characteristic ballistics of the projectiles. And the pressure value detected and the pattern of the pressure change vary with the transient space eifect and the characteristics of tissue damage.
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The effects of the temporary cavities and pressure waves of peripheral nerves were studied following 5.56mm and 7.62mm bullets shooting the soap block and both thighs of dogs. The studies indicated that there was an exponential regression correlation among the displacement and stretching ratio of nerves and temporary cavity, the maximum of pressure peak(MPP), and energy absorption (EA). The degree of nervous injuries depended on the temporary cavity volume and amounts of EA. The amounts of EA of 5.56mm bullets were 40.67kg?m,2.5 times as much that of 7.62mm bullets.MPP of 5.56mm bullets was 1.8 times as of 7.62mm.This suggested that the nerve injuries caused by 5.56mm bullets were more severe than of 7.62mm bullets. Pathological examination showed that the microstructure of nerves was damaged though the microstructure unchanged. Fibre-broken-up, bleeding in perineurium, deformation of axon, mitochondria swelling and axon membrane dividing from its myelin sheath could be seen. In 5.56 bullet wounding group the potential latency was prolonged and the amplitude decreased remarkedly. This indicated that the nerves were only damaged partially. In early management it is important to release intraneural pressure, remove the hematoma in the fascia to recover microcirculation.
ABSTRACT
This paper is to report the study of the characteristics of the temporary cavitations produced by two kinds of bullets on the soft tissues of dogs. The diameters of the bullets were 5.56mm and 7.62mm respectively. And the experiments were performed on 35 dogs. High speed roentgenography of the injured parts was taken 0.268-5.690 ms after injury. It was found that the cavity produced by 5.56mm bullet was formed earlier, existed longer, and was accompanied heavier soft tissue damage than that produced by 7.62mm bullet. It was also found that the characteristics of the temporary cavity were closely related to the amount of the energy transmitted from the bullet to the surrounding tissues, the construction of the bullet and its ballistic behavior in the tissues.
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Pathohistological observations on the soft tissue wounds experimentally produced with steel-bullets of three different weights and 8 different velocities were carried out on 42 dogs. It was found that if the weight of the bullets was identi- cal while their velocities were different, the severity of the injury and the extent of the contusion zone were directly related to the velocity of the bullet. The characteristic feature was that the injury at the entrance of the bullet was more severe than that at the exit. It might be resulted from the fact that the energy of the bullet was rapidly delivered soon after it penetrated the skin because of its light weight and the high resistance of the tissues.
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In order to assess whether there is any possibility of early reconstructive surgery to repair oromaxillofacial soft tissue defect resulting from gun-shot wound.8 dogs were wounded in the left cheek with model Mm bullet of 5.56 mm in diameter fired from a M]6 rifle made in USA with a firing distance of 6 meters.As a result,there was a hole in the left cheek of the dogs.Debridement was performed,immediately and it was repeated 72 hours after wounding.Meanwhile,saphenous artery skin flap was excised and used to repair the skin defect of the left cheek with microvascular anastomosis.The defect of the mucous membrane was repaired by drawing the adjacent mucous membrane together or by a sliding mucous membrand flap.The dogs were observed for 2 to 6 months postoperatively.The survival rate of the free skin flap was 75%.Our findings suggest that it is practicable to perform early reconstructive surgery for the repair of the oromaxillofacial soft tissue defect resulting from gunshot wound with vascular anastomotic free skin flap.
ABSTRACT
To investigate the temporal variation of cell mediated immunity in injured tissue of maxillofacial firearm trauma. Cells expressing messenger RNA(mRNA) for IL 2 were demonstrated by dot blotting and in situ hybrization in injured tissue of maxillofacial trauma inflicted by bullet, in conjunction with immunohistochemistry for IL 2 in normal and postinjury conditions. It was found that, apart from a transient eleratim in level within 24h post injury, both IL 2 production and IL 2 mRNA expression were consistently suppressed in cells at the site of the wound compared with the normal. The changes in the tissues of indirect injury by the projectile were significant. These results indicate that the cell-mediated immunity was suppressed in maxillofacial firearm trauma and the principal cellular abnormalities that resulted in altered T cell activation and IL 2 production postinjury was downregulation of mRNA before IL 2 gene transcription. It also suggested that the indirect injury by projectile contribute mainly to the depression of cell mediated immunity.
ABSTRACT
On the basis of experimental results and clinical observations, the mechanism of injury and clinical features of wounds inflicted by modern weapons are evaluated from the view-point of wound ballistics. It is emphasized that, in order to accurately assess the injury, to formulate an appropriate treatment regime, and to prevent misdiagnosis, it is essential to learn the fundamental principles of wound ballis tics.