[Three-dimensional reconstruction technique in gastrocnemius flap surgery: initial clinical application].

OBJECTIVE: To discuss the experience with three-dimensional reconstruction technique in initial clinical application in gastrocnemius muscle flap surgery. METHOD: From 2007 to 2008, 7 patients received gastrocnemius muscle flap surgeries to repair the wounds. Preoperative CT angiography or magnetic resonance imaging (MRI) was performed after injection of the contrast media for individualized three-dimensional gastrocnemius muscle flap reconstruction using Amira4.1 software. According to the size of the defect in the wound, individualized three-dimensional gastrocnemius muscle flap was designed and harvested from the posterior leg. RESULTS: Individualized three-dimensional reconstruction of the gastrocnemius flap was performed in 7 cases, and the reconstructed flaps clearly displayed the blood vessels, skin and the adjacent three-dimensional structures. In 6 cases the main perforating branched and trunk of the blood vessels in the designed flap were consistent with the surgical findings; in 1 case, the perforating branches failed to be clearly displayed in the designed flap, and surgical examination identified perforating branches with an average diameter of 0.5 mm (minimally 0.3 mm). The flaps survived in all the 7 cases. CONCLUSIONS: Three-dimensional reconstruction of the gastrocnemius flap based on the lower limb CT angiography or MRI allows three-dimensional observation of the anatomy of the flap and accurate marking of the extent of the flap to be harvested, therefore avoiding intraoperative injuries to the blood vessels to better survival of the flaps.

Replantation of articular composite tissue masses severed from extremities.

SUMMARY: The techniques and outcomes of in situ replantation are discussed for managing 5 cases of articular composite tissue masses severed from an extremity (digit). All 5 cases treated with in situ replantation survived. Rehabilitation was performed after surgery. Follow-ups of 2-5 years showed good appearance, satisfactory functional and sensory recovery. In situ replantation is indicated for an articular composite tissue masses severed from an extremity (digit), if its structure is complete and a blood supply vessel in the mass is available for anastomosis. Replantation can achieve better outcomes than transfer or grafting of adjacent skin or osteocutaneous flaps, or transplantation of a metatarsophalangeal or interphalangeal joint.

Reconstruction of phalangeal articulations of the hand with vascularised phalangeal articulations of foot.

SUMMARY: Since arthroplasty, prosthetic replacement and non-vascularised articulation autografting do not normally produce very satisfactory results for ankylosis of metacarpophalangeal and interphalangeal joints, the authors performed reconstruction of phalangeal articulations of the hand using vascularised phalangeal articulations of the foot in 11 patients with ankylosis of the metacarpophalangeal and interphalangeal joints of hand due by trauma. Procedures included reconstruction of 9 hand metacarpophalangeal joints with vascularised grafting of pedal metatarsophalangeal joints in six patients, reconstruction of the hand metacarpophalangeal joints with grafting of vascularised proximal interphalangeal joints of foot in two patients and reconstruction of the hand proximal interphalangeal joints with grafting of vascularised proximal interphalangeal joints of foot in three patients. Early functional exercise was encouraged in all cases post-operatively. Follow-up ranged from 3 to 10 years and revealed that 9 cases had normal appearance and length of recipient area, 1 had slightly clumsy dorsal skin in the hand and 1 had slight dorsal angulation of a metacarpal bone. Recovery of joint range of motion was satisfactory. Radiographic, gross and sensation examinations also showed good operative outcomes. The authors believe that vascularised pedal metatarsophalangeal joints, with a rich blood supply, can be grafted to effectively reconstruct the finger joints with good function. A low rate of degeneration results because pedal and hand metatarsophalangeal joints are similar in anatomy and physiological function.

[Green fluorescent protein as a tracer of bone marrow stromal cells in bone tissue engineering in rhesus].

OBJECTIVE: To observe the role of green fluorescent protein (GFP) in tracing rhesus bone marrow stromal cells (rBMSCs) during tissue-engineered bone formation in vivo. METHODS: Ad5.CMV-GFP was amplified by infecting QBI-293A cells, and the bone marrow was harvested from the ilium of adult male rhesus to obtain rBMSCs, which were cultured and passaged in vitro. GFP was transfected into the third-passage rBMSCs via adenovirus vector and the labeled cells were inoculated into absorbable HA scaffold and cultured for 3 days, with untransfected rBMSCs as control, before the cell-matrix compounds were implanted into the latissimus dorsi muscles of rhesus. Samples were harvested at 6 week and embedded in paraform, and ground sections of the bone tissue were prepared to observe green fluorescence under laser scanning confocal microscope. Propidium iodide staining of the sections was also performed for observation. RESULTS: The rBMSCs grew well after GFP transfection, and green fluorescence could be seen 24 h after the transfection and became stronger till 48 h, with a positive transfection rate beyond 80%. Six weeks after cell implantation, the rBMSCs labeled by GFP-emitted green fluorescence were detected in the bone tissue under laser scanning confocal microscope. CONCLUSION: GFP can effectively trace BMSCs during bone tissue engineering, and the transplanted BMSCs constitute the main source of bone-forming cells in bone tissue engineering.

Distribution and property of nerve fibers in human long bone tissue.

OBJECTIVE: To observe the distribution of the nerve fibers in the bone tissue and the entry points of these fibers into the bone. METHODS: The adult tibia was used for the ground sections which were afterwards made into the slice sections by decalcification in ethylenediamine tetraacetic acid (EDTA). The ground sections were stained in silver and the slice sections were stained in silver and haematoxylin and eosin (HE) respectively. Then, the samples of the transmission electron microscope and the atomic force microscope were made and observed. RESULTS: In the human long bone tissue, many nerve fibers were distributed in the membrane, cortical bone, cancellous bone and marrow. The nerve fibers entered the bone from the nutrient foramen, and passed through the nutrient canal, Haversian's canal and Volkmann's canal, and finally into the bone marrow. In the nutrient canal, the nerve fibers, mainly the medullary nerve fibers, followed the blood vessel into the bone. In the cortical bone, the nerve fibers also followed the blood vessels and were mainly distributed along Haversian's canal and Volkmann's canal. In the bone trabecular and bone marrow, there were many nerve fiber endings arranged around the blood vessels, mainly around the tunica media of medium-size arteries in the marrow and around capillary blood vessels, and a few scattered in the bone marrow. There were sporadic nerve endings in epiphyseal plate and no nerve fibers permeated epiphysis to diaphysis. No distribution of nerve fibers could be found in cartilaginous part. CONCLUSIONS: There are many nerve fibers in bone and the nerve passageway is nutrient foramen, Volkman's canal, Haversian's canal and bone marrow.

[Perfusion-weighted magnetic resonance imaging for monitoring vascularization in tissue-engineered bone in rhesuses].

OBJECTIVE: To assess the value of perfusion-weighted magnetic resonance (MR) imaging (PWMRI) in monitoring vascularization in tissue-engineered bone graft. METHODS: Tibial diaphyseal defect of 20 mm was induced in 25 lower limbs of 13 rhesuses and fixed with an AO reconstruction plate with 7 holes. The monkeys were randomized into 5 groups according to the materials used for defect filling: group A, with beta-tricalcium phosphate (beta-TCP), bone marrow stromal cells (BMSCs) and blood vessel bundles; group B, with beta-TCP and blood vessel bundles; group C, with beta-TCP and BMSCs; group D, with beta-TCP, and group E without filling. PWMRI, X-ray, and radionuclide imaging were carried out at weeks 4, 8, 12 postoperatively. The maximum slope rates of the single intensity-time curve (SS(max)) and the baseline values (SI(baseline)) on the same time points were calculated. Transmittances on the X-ray films and isotope counts in the region of interest (ROI) were assessed and calculated. RESULTS: Compared with other groups, group A showed the highest SS(max) at weeks 4, 8, and 12 postoperatively, and its SS(max) at week 8 was significantly higher than that at week 4 (P=0.003). The SS(max) was positively related to isotope counts in ROI at week 8 after operation (r(s)=0.899, P=0.038), and inversely related to transmittance on X-ray films at week 12 (r(s)=-0.892, P=0.042). CONCLUSION: The SS(max) of the single intensity-time curve can accurately reflect the vascularization of the tissue-engineered bone graft, and PWMRI allows sensitive, quantitative, noninvasive and radiation-free vascularization monitoring.

[Bone defect repair with a new tissue-engineered bone carrying bone morphogenetic protein in rabbits].

OBJECTIVE: To construct a new tissue-engineered bone with poly (D, L-lactide-co-glycolide) (PLGA), bone morphogenetic protein (BMP) and bone marrow-derived stem cells (BMSCs) and observe its effect in repairing segmental bone defects. METHODS: A 15-mm bone defect in the right radius was induced in New Zealand white rabbits, and the models were randomized into three groups to receive implantation of the tissue-engineered bone grafts constructed with PLGA carrying 5 mg BMP and about 1 x 10(6) BMSCs (experimental group), grafts of PLGA with about 1 x 10(6) BMSCs (control group), or grafts of exclusive PLGA (blank control group), respectively. The osteogenesis in the bone defect after the implantation on was evaluated X-ray films, and the histological changes of the tissues sampled from the bone defect 4, 8, and 12 weeks after operation were observed and new bone formation was measured by image analysis. RESULTS: The bone defect was completely repaired in the experimental group 12 weeks after the implantation, showing the best results among the 3 groups. The bone defects in the blank control group was filled with only fibrous and connective tissues at 12 weeks. CONCLUSION: This tissue-engineered bone constructed with PLGA, BMP and BMSCs possesses good ability in repairing segmental bone defect.

[In vitro biocompatibility of novel absorbable hydroxyapatite and AO artificial bone beta-tricalcium phosphate with rhesus bone marrow stromal cells].

OBJECTIVE: To study the in vitro biocompatibility of novel hydroxyapatite (HA) and AO artificial bone beta-tricalcium phosphate (beta-TCP) with rhesus bone marrow stromal cells (rBMSCs) . METHODS: The third passage of rBMSCs were cultured with HA and beta-TCP respectively, with the cells cultured without the materials as the control. The morphology and proliferation of cells were observed by inverted phase-contrast microscope and scanning electron microscope (SEM). MTT assay was used to semiquantitatively evaluate the cell proliferation. RESULTS: The rBMSC cocultured with HA exhibited good growth as observed under inverted phase-contrast microscope, without significant difference from the cells in the control group. Some small particles were seen pealing off from beta-TCP, and some of the cells died. Under SEM, rBMSCs showed good adhesion to HA with obvious proliferation, but the ratio of adhesive cells was not as high as that in beta-TCP group. MTT assay showed no significant difference in the cell number between HA and the control groups, but the cell number in beta-TCP group was notably less than that of control group. CONCLUSION: Novel HA has good biocompatibility with rBMSCs for bone tissue engineering, and AO artificial bone still needs improvement to serve as scaffold material for BMSCs.

[Effect of bone morphogenetic protein microspheres on biological behavior of rabbit bone marrow stem cells].

OBJECTIVE: To evaluate the effect of bone morphogenetic protein (BMP) on the biological behavior of bone marrow stem cells (BMSCs) of rabbits. METHODS: BMP was either enwrapped or not in the microspheres made of chitosan and sodium alginate, and the biocompatibilities of the composites were examined by means of cell culture. The BMSCs were cultured with the two kinds of microspheres respectively, and the cell extension rate, proliferation, alkaline phosphatase activity and Coomassie blue staining of the cells were assayed. RESULTS: Inhibition of BMSC proliferation did not occur in response to in vitro culture with the microspheres, but alkaline phosphatase activity and D(lambda) values of Coomassie blue staining increased significantly in the cells cultured with BMP microspheres. CONCLUSION: BMP can increase the osteogenic capacity of BMSCs in vitro with the microspheres made of chitosan and sodium alginate as the carrier.

[The regulatory effect of human bone morphogenetic protein 7 gene transfer on the proliferation and differentiation of rabbit bone marrow mesenchymal stem cells].

OBJECTIVE: To detect the proliferation and differentiation of rabbit bone marrow mesenchymal stem cells (BMSc) transferred by retroviral vector carrying human bone morphogenetic protein 7 (hBMP-7) gene. METHODS: hBMP-7-expressing replication-deficient retroviral vector(PT-PLNCX2-hBMP7) was reconstructed using clone technique and recombinant DNA technique. BMSc were infected with the virus granules. The protein of BMP-7 gene in transferred cells were determined by immunohistochemistry. The proliferativity of the transferred cell were assayed by methabenzthiazuron (MTT) method and flow cytometer. Alkaline phosphatase (ALP) were also detected using enzyme kinetics. RESULTS: Cells transferred by PT-PLNCX2-hBMP7 expressed abundant hBMP7 protein in the cytoplasm. Positive findings were not found in those cells that were not transferred. After infected with virus there were not significant difference of cell proliferation and cell cycle between the cells transferred by hBMP-7 or not (P > 0.05). ALP activity in transferred cells were increased significantly (P < 0.01). CONCLUSIONS: hBMP-7 can be transferred and stably expressed in the cultured rabbit bone marrow stem cells. Proliferation and cell cycle of the transferred cell were not affected. hBMP7 gene transfer can be used to induce differentiation of BMSc into osteoblast-like cells.

[The method of accelerating osteanagenesis and revascularization of tissue engineered bone in big animal in vivo].

OBJECTIVE: To study whether tissue engineered bone can repair the large segment bone defect of large animal or not. To observe what character the fascia flap played during the osteanagenesis and revascularization process of tissue engineered bone. METHODS: 9 Chinese goats were made 2 cm left tibia diaphyseal defect. The repairing effect of the defects was evaluated by ECT, X-ray and histology. 27 goats were divided into three groups: group of CHAP, the defect was filled with coral hydroxyapatite (CHAP); group of tissue engineered bone, the defect was filled with CHAP + bone marrow stroma cells (BMSc); group of fascia flap, the defect was filled with CHAP + BMSc + fascia flap. After finished culturing and inducing the BMSc, CHAP of group of tissue engineered bone and of fascia flap was combined with it. Making fascia flap, different materials as described above were then implanted separately into the defects. Radionuclide bone imaging was used to monitor the revascularization of the implants at 2, 4, 8 weeks after operation. X-ray examination, optical density index of X-ray film, V-G staining of tissue slice of the implants were used at 4, 8, 12 weeks after operation, and the biomechanical character of the specimens were tested at 12 weeks post operation. RESULTS: In the first study, the defect showed no bone regeneration phenomenon. 2 cm tibia defect was an ideal animal model. In the second study, group of CHAP manifested a little trace of bone regeneration, as to group of tissue engineered bone, the defect was almost repaired totally. In group of fascia flap, with the assistance of fascia flap which gave more chance to making implants to get more nutrient, the repair was quite complete. CONCLUSIONS: The model of 2 cm caprine tibia diaphyseal defect cannot be repaired by goat itself and can satisfy the tissue engineering's demands. Tissue engineered bone had good ability to repair large segment tibia defect of goat. Fascia flap can accelerate the revascularization process of tissue engineered bone. And by this way, it augment the ability of tissue engineered bone to repair the large bone defect of goat.

[Repair of tibial defect with tissue-engineered bone graft and radionuclide bone imaging in goats].

OBJECTIVE: To observe the effect of tissue-engineered bone grafts in repairing large tibial defect in goats, and assess the value of radionuclide bone imaging in monitoring the therapeutic effect of this approach. METHODS: Tibial defects measuring 2 cm was artificially made in the left tibia of 27 normal goats that were subsequently divided into 3 groups (9 each) to undergo treatment with tissue-engineered bone grafts, artificial bone grafts or without any grafts (as control group) respectively. The tissue-engineered bone grafts contained bone marrow stroma cells (BMSCs) of the goats and coral hydroxyapatite (CHAP), while the artificial bone grafts were from CHAP only. After the operations, radionuclide bone imaging was used to monitor the therapeutic effects at 2, 4 and 8 postoperative weeks. RESULTS: The 99mTc-MDP uptake of the region of interest (ROI) and the target to non-target ratios (T/NT) of the control group did not indicate any process of revascularization or bone regeneration. An increasing tendency of the revascularization and bone regeneration, in contrast, was observed in goats receiving the artificial bone grafts, a tendency that was far more obvious in the goats with tissue-engineered bone grafts. CONCLUSION: Tissue-engineered bone graft is eligible in repairing large defect in the caprine tibia, and radionuclide bone imaging may accurately monitor the revascularization and bone regeneration after the bone graft implantation.

[Biocompatibility of adult human osteoblasts with coral-derived hydroxyapatite in vitro].

OBJECTIVE: To study the biocompatibility of the osteoblasts from adult human bone marrow with coral-derived hydroxyapatite (CHA) in in vitro culture. METHODS: Bone marrow was obtained from healthy adult subjects and cultured in Dulbecco's modified Eagle's medium (DMEM) containing 10 % fetal bovine serum. The subsequent cell passaging was conducted in conditioned medium containing dexamethasone, beta-sodium glycerophosphate and ascorbic acid, with the osteoblasts in culture then divided into CHA group (in which the cells were cultured with CHA) and osteoblasts group (without CHA). The proliferation and differentiation of all the cultured cells were observed at different time points under inverted phase contrast microscope, optical microscope with HE staining and scanning electron microscope respectively. Proliferation of the cultured cells were evaluated by MTT assay, and the activity of alkaline phosphatase and total micro-protein contents in these cultured osteoblasts were quantitatively detected. RESULTS: The osteoblasts from adult human bone marrow grow well in vitro, regardless of the presence of CHA, with biological and morphological characteristics similar to those of normal osteoblasts. CHA improved the adhesion, growth and proliferation of the cultured cells, showing no adverse effects on the cell functions. CONCLUSION: CHA is an optimal scaffold material for bone tissue engineering, which may potentially find clinical application for bone defect repair.

[mRNA expression of recombinant human bone morphogenetic protein 7 in skeletal muscle satellite cells with retroviral vector-mediated rhBMP7 gene transfection].

OBJECTIVE: To detect the expression of recombinant human bone morphogenetic protein7 (rhBMP7) in skeletal muscle satellite cells (SMSCs) with rhBMP7 gene transfection mediated by retroviral vector. METHODS: rhBMP7 gene was reconstructed in retroviral vector and transferred into packaging cells PT67 via liposome reagent, with the positive cell clones selected with G418. In vitro cultured SMSCs were transfected with the virus granules secreted by PT67 cells and followed by G418 selection. Reverse transcriptase-polymerase chain reaction was utilized for analysis for rhBMP7 mRNA in the transfected cells. RESULTS: rhBMP7 retrovirus vector was successfully constructed and transferred into PT67 cells, and abundant mRNA expression of rhBMP7 was observed in the skeletal muscle satellite cells transfected with the virus and selected with G418. CONCLUSION: rhBMP7 gene can be transferred into the skeletal muscle satellite cells via retroviral vector to yield effective rhBMP7 mRNA expression.

[Dynamic changes of SOD and MDA in canine limbs with gunshot wound in hot and humid environment: an experimental study].

OBJECTIVE: To study the dynamic changes in lipid peroxidation and the activity of antioxidative enzyme in canine limbs with gunshot wound in hot and humid environment. METHODS: Eighteen dogs with gunshot wound were randomly assigned into 3 groups with equal numbers. Dogs observed after injury in normal environment was designated as NE group, those in hot and humid environment as HHE group and those in hot and humid environment with preceding heat acclimatization training as HA group. Contents of superoxide dismutase (SOD) and malonaldehyde (MDA) in both the peripheral blood and muscular tissues from gunshot wound tract were measured at 0, 1, 3, 4, 6, 8, 10, 14, 18 and 24 h respectively after the dogs had been wounded. RESULTS: Positive correlation between SOD and MDA contents was observed in each group. Three hours after injury, MDA level in HHE group began to ascend, reaching the peak level at 6 h that was significantly higher than those in the other 2 groups (P<0.05); SOD level underwent a reverse change, which was significantly lower in HHE group than in the other groups with that in HA group being the highest. Comparable SOD levels in the groups occurred at the time of 14 h, which happened to MDA levels 4 h later. CONCLUSION: Gunshot injuries in the limbs of dogs exposed to hot and humid environment induces increased free oxygen and aggravated the lipid peroxidation, which can be alleviated by heat acclimatization.

[Expression of human bone morphogenetic protein 7 mRNA after the gene transfection in rabbit bone marrow-derived mesenchymal stem cells].

OBJECTIVE: To detect the expression of human bone morphogenetic protein 7 (hBMP-7) mRNA in rabbit bone marrow-derived mesenchymal stem cells with hBMP-7 gene transfection mediated by retroviral vector. METHODS: Retroviral vector for hBMP-7 gene was constructed that was transferred into the packaging cell PT67 mediated by liposome. hBMP-7 gene-positive cell clones were selected with G418 (600 ng/ml) and amplified to obtain the retroviral supernatant containing the target genes that were subsequently used to transfect rabbit bone marrow-derived mesenchymal stem cells (MSCs). HBMP-7 mRNA expression in the MSCs was examined by way of in situ hybridization and reverse transcriptase-polymerase chain reaction. RESULTS: hBMP-7 retroviral vector was successfully constructed and transferred into PT67 cells with resistance to G418, and after transfection with the recombinant retrovirus, transcription and expression of hBMP-7 mRNA were detected in MSCs. CONCLUSION: Rabbit bone marrow stem cells transfected with hBMP gene via retroviral vector can secrete the correspondent protein, indicating the possibility of enhancing the osteogenic capacity of MSCs in the study of bone tissue engineering.

[Bacterium culture and flora analysis of gunshot wound on limbs of dogs in hot and humid environment].

OBJECTIVE: To investigate the time of bacterial invasion into the blood and conduct flora analysis of the blood and secretions in the gunshot wound in the limbs of dogs in hot and humid environment. METHODS: Gun-shot wound was induced in 8 dogs who were subsequently assigned at random into hot and humid environment (HHE) group and normal environment (NE) group for observation. At the time points of 0, 4, 6, 8, 12, 24 h after injury, body temperature was measured and bacterial culture and flora analysis performed. RESULTS: Body temperature elevation occurred earlier and lasted for longer time in HEE group than in NE group. Bacterial invasion into the blood occurred at 12 h after the injury in NE group, but at 8 h in HHE group. In the wound tracts of the dogs, surface bacteria were found in both groups. Surface bacteria were also found in the blood of dogs in both groups, but in HHE group, even intestinal flora were identified. CONCLUSION: Body temperature elevation and bacterial invasion into the blood occurred at an earlier time in hot and humid environment where migration of intestinal bacteria into the blood easily takes place, indicating the early application of broad-spectrum antibiotics under such environmental conditions.

Effect of X-ray irradiation on limb allograft rejection in adult rats.

OBJECTIVE: To establish appropriate animal models for observing the effects of X-ray irradiation on limb allograft rejection. METHODS: Wistar rats were used as donators and SD rats as recipients, the latter divided into 2 groups, namely irradiation group and non-irradiation group according to pretransplant treatment with or without X-ray radiation (5 Gy) on the part of the donators. The donor limbs were transplanted into SD rats who had their own limbs cut off, and the sciatic nerve, femoral nerve, and femoral artery and femoral vein were anastomosed in operation. After the operation, all the recipients were given benzathine benzylpenicillin, and their vital signs, together with changes of the allografts, observed. RESULTS: A total of 16 rats received transplantation that was successful in 6 rats of non-radiation group and 7 of irradiation group. The graft survival averaged 12.0+/-2.4 d in non-irradiation group and 24.7+/-8.1 d in irradiation group, showing significant difference in the lengths of survival between the 2 groups (P<0.05). CONCLUSION: The graft survival time in rats can be significantly prolonged by pretransplant irradiation of the allograft, which also help control acute rejection of the allograft.

[Effects of bone morphogenetic protein on proliferation and collagen-1 synthesis of skeletal muscle satellite cells].

OBJECTIVE: To investigate the effects of bone morphogenetic protein (BMP) on the proliferation and collagen synthesis of skeletal muscle satellite cells. METHODS: Skeletal muscle satellite cells were harvested and cultured in vitro. The 0 ng/ml, 50 ng/ml, 100 ng/ml, 500 ng/ml, and 1000 ng/ml BMP were used to induce skeletal muscle satellite cells for 48 hours. Cell proliferation, rate of myotube formation and collagen-1 synthesis were measured. RESULTS: BMP promoted cell proliferation and reduced the rate of myotube formation. Collagen synthesis increased when skeletal muscle satellite cells were induced with more than 500 ng/ml BMP. And the higher the concentration of BMP was, the stronger this effect became. CONCLUSION: BMP can enhance the proliferation of skeletal muscle satellite cells and change their differentiation from myoblasts to osteoblasts.

Dynamic changes of TNF-alpha content in dogs after gunshot wound in the limbs in hot and humid environment.

OBJECTIVE: To investigate the dynamic changes of TNF-alpha content in the plasma and body tissues of dogs after gunshot wound in the limbs in hot and humid environment. METHODS: Eighteen dogs with gunshot wound were divided into 3 groups (6 in each), one observed in normal environment (Ne group) and the other two in hot and humid environment including a heat-acclimatized group (HA group) and a non-acclimatied group (NHA group). The contents of tumor necrosis factor-alpha (TNF-alpha) in the plasma and muscle tissues from the gunshot wound tract were measured at 0, 1, 3, 4, 6, 8, 10, 14, 18, 24 h respectively after the injury. RESULTS: TNF-alpha content in the muscular tissue from gunshot wound tract was significantly higher than that in the plasma (P<0.05). At 4 h after injury, TNF-alpha content started to rise in NE group, reaching the peak level at 14 h, the rise and peaking of which occurred at 3 and 10 h respectively in NHE group with higher peak level than that in NE group (P<0.05). The changes of TNF-alpha participates in the pathophysiological process after gunshot wound in hot and humid environment and may play the role of and indicator for the pathological changes that take place after the injury.