Effect of gene transfection at different time on bone mineral density and strength of newly formed bone in mandibular distraction gap in rabbit / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of gene transfection at different time on bone mineral density and strength of newly formed bone in mandibular distraction gap in rabbit, so as to explore the optimal time for gene therapy and enhance the therapeutic effect.</p><p><b>METHODS</b>48 New-Zealand rabbits were employed to receive mandibular osteotomy and implantation of distraction devices bilaterly. Then the rabbits were randomly divided into 4 groups as group A, B and C and D. The animals in group A, B, and C were transfected with recombinant plasmids pIRES-hBMP2-hVEGF165 via electroporation-mediated approach at latency period, distraction period, consolidation period respectively. Group D was used as control group without gene transfection. After 3 days of latency period, the distraction devices were activated at the rate of 0.8 mm per day for 10 days. Three rabbits in each group were sacrificed at 1 wk, 2 wk, 4 wk and 8 wk of consolidation respectively. The mandibles were harvested and the left mandible received X-ray examination for bone healing, and quantitative computed tomography (QCT) dectection for the bone mineral density (BMD) of newly formed bone in the distraction gap. The biomechanical properties of the new generation bone at 4 th and 8 th week of consolidation in each group were detected by three point bending test.</p><p><b>RESULTS</b>The bone mineral density and the biomechanical strength of newly formed bone increased along the length of consolidation in each group. After 1 week of consolidation, there was no significant difference in BMD among group A (83.43 +/- 9.96), group B (92.29 +/- 11.25), group C (89.93 +/- 14.15), P > 0.05. But the BMD of group A, B and C was higher than that of group D (70. 31 +/- 3.30), P < 0.05. After 2wk, 4 wk and 8 wk of consolidation, the BMD of group B (137.54 +/- 7.20,492.93 +/- 17.57, 790.48 +/- 12.19) was significantly higher than those of group A (121.44 +/- 9.27, 396.15 +/- 15.70, 603.39 +/- 16.46), C (125.06 +/- 7.24, 464.15 +/- 15.45, 764.15 +/- 17.28), and D (98.86 +/- 8.13, 336.45 +/- 11.95, 577.89 +/- 18.43), P < 0.05. The biomechanical parameters were also higher in group B than those of group A, C and D after four and eight weeks of consolidation (P < 0.05).</p><p><b>CONCLUSION</b>It is better to transfect gene at the beginning of distraction (distraction period) than at other stages of DO. In this way, more remarkable effect could be obtained on new bone formation. It suggests that the distraction stage is the optimal time for gene therapy.</p>

Effect of electroporation-mediated gene transfect on the expression of cyclins during mandible distraction in rabbit / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of electroporation-mediated gene transfect on the expression of cyclins during mandible distraction in rabbit.</p><p><b>METHODS</b>Bilateral mandibular osteotomy was performed in 45 New-Zeland rabbits. After a latency of 3 days, the mandibles were elongated using distractors with a rate of 0.8 mm/day for 7 days. After the completion of distraction, the rabbits were randomly divided into 5 groups. 2 microg (0.1 microg/microl) of pIRES-hVEGF165-hBMP2, recombinant plasmid pIRES-hBMP2, recombinant plasmid pIRES-hVEGF165, pIRES and the same volume of normal saline (NS) was injected into the distraction area in each group, respectively. After injection, electroporation was performed in every group. Three animals in each group were sacrificed at 7, 14, and 28 days after completion of distraction, respectively. The lengthened mandibles were harvested and processed for immunohistochemical examinations. The expression of cyclins A, D1 ,E in positive cells were measured by CMIAS-2001A computerized image analyzer. The data were analyzed with the single factor analysis of variance and q test.</p><p><b>RESULTS</b>Cyclins A, D1, E staining was mainly located in inflammatory cells, granulation tissue monocyte, fibroblast, osteoblasts, osteocyte and the connective tissues around the new bone. The expression reached to the peak at 7th day of consolidation, and decreased at 14th day, and weak at 28th day. Image analysis results showed that, at 7th day, the expression absorbance A in group C (0.59 +/- 0.14) was the strongest, compared to group A (0.41 +/- 0.13), B (0.38 +/- 0.14), D (0.34 +/- 0.12) and E (0.31 +/- 0.10), showing a significant difference (P < 0.05, P < 0.01). There was no significance difference between group A and B (P > 0.05), but the difference between group A/B and group D/E (P < 0.05). At 14th and 28th day, there was no significant difference among group A (0.39 +/- 0.11), B (0.34 +/- 0.10) and C (0.33 +/- 0.09) (P > 0.05), but there was significant difference between group A/B/C and group D (0.19 +/- 0.12) or E (0.14 +/- 0.04) (P < 0.05 or P < 0.01).</p><p><b>CONCLUSIONS</b>Electroporation-mediated gene transfection can promote cyclins A, D1, E expression effectively, which may promote cell differentiation and proliferation, stimulate extracellular matrix synthesis and new bone formation in distraction gap.</p>

Correlation between serum growth differentiation factor-15 and TIMI risk scores in patients with unstable angina pectoris / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the correlation between serum levels of growth differentiation factor-15 (GDF-15) and Thrombolysis in Myocardial Infarction (TIMI) risk scores in patients with unstable angina pectoris (UA).</p><p><b>METHODS</b>The serum levels of GDF-15 in 97 patients with UA and 30 healthy volunteers were measured using enzyme-linked immunosorbent assay (ELISA) and compared between 3 patient groups with different TIMI scores to analyze relationship between serum GDF-15 levels and TIMI risk scores.</p><p><b>RESULTS</b>The serum levels of GDF-15 in UA patients were significantly higher than those in the healthy volunteers (P<0.01). GDF-15 levels also differed significantly between patients with different TIMI scores (P<0.01), and showed a significant positive correlation to TIMI risk scores.</p><p><b>CONCLUSION</b>Serum levels of GDF-15 can be used as an index for evaluating the severity of UA.</p>

Influence of serum from rats with scald on the cytoskeleton of colonic smooth muscle cells of rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the influence of serum from scalded rats on the cytoskeleton of colonic smooth muscle cells (CSMC) of rats cultured in vitro, and to probe the possible mechanism of gastrointestinal motility disorder after burn.</p><p><b>METHODS</b>CSMC isolated from healthy adult Wistar rat were cultured and divided into scald serum group (SS) and normal serum group (NS) according to the random number talbi. Two normal Wistar rats were used, one of which was inflicted with deep partial-thickness scald. Serum was obtained from blood collected from these two rats respectively and diluted to 20% in concentration. Serum from scald and normal rats were respectively added to the culture of CSMC in SS and NS groups. The expression of actin and the relative content of β-tubulin in CSMC was respectively determined with flow cytometry and Western blot at post treatment hour (PTH) 1, 3, 6, and 12 (with 10 samples in each group at each time point). Data were processed with t test.</p><p><b>RESULTS</b>Fluorescence intensity of actin in SS group at PTH 1, 3, 6, and 12 was respectively 59 ± 4, 26 ± 6, 39 ± 6, and 42 ± 6, all significantly lower than those in NS group (95 ± 10, 91 ± 10, 102 ± 9, and 97 ± 9, with t value respectively 10.528, 18.069, 18.748, 16.647, P < 0.05 or P < 0.01). In SS group, the fluorescence intensity decreased to the nadir at PTH 3, and then increased persistently at PTH 6 and 12. (2) Relative content of β-tubulin in SS group at PTH 1, 3, 6, and 12 was respectively 14.44 ± 0.26, 8.61 ± 0.19, 11.76 ± 0.31, and 12.13 ± 0.29, all significantly less than those in NS group (22.37 ± 1.15, 21.87 ± 1.79, 23.24 ± 1.55, and 21.99 ± 2.02, with t value respectively 21.176, 23.365, 23.000, 15.273, P values all below 0.01). In SS group, the relative content of β-tubulin decreased to the nadir at PTH 3 and increased slowly at PTH 6 and 12.</p><p><b>CONCLUSIONS</b>The reduction of CMSC content which has the tendency of increasing later, can be attributed to the influence of scald serum in initial stage. This may be related to the tolerance and adaptation to scald serum and self-repair of CMSC.</p>

The effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap in rabbit / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the effect of electroporation mediated gene therapy on bone mineral density and strength of new-formed bone in mandibular distraction gap, so as to enhance the osteogenesis and shorten the distraction term.</p><p><b>METHODS</b>New-Zealand rabbits were employed. The distraction began after 3 days of latency period at the rate of 0. 8 mm per day for 7 days. After distraction, the rabbits were randomly divided into 5 groups to receive injection in the distraction gap with recombinant plasmid 2 microg (0.1 microg/microl) pIRES-hVEGF165-hBMP2 in group A, with recombinant plasmid pIRES-hBMP2 in group B, with recombinant plasmid pIRES-hVEGF165 in group C, with pIRES in group D, and with normal saline (NS) in group E. After injection, electroporation was performed in all the groups. After 1 week, 2 weeks, 4 weeks and 8 weeks of consolidation, all the animals underwent X-ray and quantitative computed tomography (QCT). The new-formed bone in distraction gap was selected as regions of interest (ROI) to measure the bone mineral density(BMD). Then the rabbits were sacrificed and the new-formed bone samples were harvested to detect 3-point crushing strength.</p><p><b>RESULTS</b>BMD of newly formed bone in group A, B and C was markedly higher than that in group D and E (P < 0.01). After 2 weeks of consolidation, BMD in group A was much higher than that in the other groups, but there was no difference between group B and C. After 4 weeks of consolidation, BMD in group A and B was markedly higher than that in group C, D and E (P < 0.01). After 8 weeks of consolidation, BMD in group A was markedly higher than that in the other groups. While the BMD was not significantly different between group B and C, but the BMD in group B and C was higher than that in group D and E (P < 0.01). After 4 weeks of consolidation, the 3-point crushing strength of newly formed bone in group A was markedly higher than that in group B,C, D and E (P < 0.01), which was still the same after 8 weeks of consolidation. And the crushing strength in group B was higher than that in group C, D and E (P < 0. 05).</p><p><b>CONCLUSIONS</b>Electroporation-mediated transfection of recombinant plasmid pIRES-hVEGF165-hBMP2 could greatly enhance osteogenesis and calcification. A combination of VEGF and BMP may promote osteogenesis and angiogenesis simultaneously, so as to magnify the effect of each growth factor, resulting a synergetic effect.</p>

Establishment of animal model for electroporation-mediated gene therapy in distraction osteogenesis of rabbit mandible / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the feasibility of electroporation-mediated transfection of recombinant plasmid to mandibular distraction area of rabbit in vivo.</p><p><b>METHODS</b>New-Zeland rabbit were employed. The mandible was distracted 3 days after operation at a rate of 0.8 mm per day for 7 days. The rabbits were randomly divided into 3 groups as group A (recombinant plasmid pIRES-VEGF165-EGFP), group B (recombinant plasmid plRES-VEGF165-EGFP) and group C (normal saline). The rabbits were sacrified at 3 hours, 1, 3, 7 and 14 d after injection respectively. The tissue at the distraction area was taken out for frozen section. The gene expression was assessed by the detection of expression of green fluorescence protein (GFP) using fluorescence microscope. The liver and kidney function test (ALT, AST, BUN, Scr) and the histological examination of heart, liver and kidney were also performed.</p><p><b>RESULTS</b>GFP was seen in the distraction area in group A and group B 3 hours after injection, which increased at the 1st day, reached peak value at the 3rd day, decreased at the 7th day and was very lower at 14th day. The GFP expression was much stronger in group A than in group B. GFP was not expressed in group C. There was no statistical difference in the concentration of ALT, AST, BUN and Scr in serum of rabbits among the three groups.</p><p><b>CONCLUSIONS</b>Electroporation-mediated transfection of recombinant plasmid can be expressed in the distraction area of rabbits, and there was no toxicity to the liver and kidney of rabbits. Electroporation could obviously improve transfection efficiency in vivo. It indicates that electroporation-mediated transfection of recombinant plasmid to distraction area tissue of rabbits is feasible.</p>

Simultaneous occlusal orthodontics during mandibular distraction osteogenesis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the significance and principle of simultaneous orthodontics during mandibular distraction osteogenesis.</p><p><b>METHODS</b>Totally 11 patients simultaneously underwent occlusal orthodontic treatment for 3-4 months during mandibular distraction osteogenesis. Square-wire and elastic loops were adapted to perform the orthodontics by ways of more frequent adjustment of orthodontic device than routine method.</p><p><b>RESULTS</b>All 11 patients with mandibular micronathia obtained the improved occlusion with their mandibular expected elongation, for instance, their open-bite and teeth displacement were partially corrected.</p><p><b>CONCLUSION</b>Simultanous orthodontics with mandibular distraction osteogenesis may improve the malocclusion, decrease the orthodontic time, and lead the mandibular distraction direction.</p>

Analysis of the complications following mandibular distraction using internal distractors / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the causes and the prophylactic for the complications following mandibular distraction osteogenesis using internal distractors.</p><p><b>METHODS</b>From 1997 to 2004, a total of 46 patients (61 sides) suffering from malformations or defects of mandible who underwent mandibular distraction osteogenesis were analyzed. The diseases included hemifacial microsomia in 27 cases, congenital or acquired mandibular hypoplasia and micrognathia bilateral in 8 cases and unilateral in 4 cases, electronical injury or postoperative mandibular defects in 3 cases, Treacher Collins syndrome in 2 cases, obstructive sleep apnea syndrome in 2 cases.</p><p><b>RESULTS</b>Of them, 9 patients had postoperative complications, which included 3 patients had complications associated with distractors, local infection occurred in 2 cases, apertognathia of anterior teeth in 2 case, 2 patients had sinus of the skin of the lower lip. 9 patients had been aggressivly managed and obtained satisfactory results.</p><p><b>CONCLUSIONS</b>The pivotal points to reduce complications are to understand the mechanism of mandibular distraction osteogenesis completely, and to be familiar with the anatomy of mandible and adjacent tissues. It is necessary to treat with it preoperatively and postoperatively.</p>

Pathological study of rabbits' femoral arteries subjected to gunshot wounds combining with seawater immersion / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate pathological characteristics of gunshot wounds concomitant seawater immersion in rabbits' femoral arteries.</p><p><b>METHODS</b>Thirty rabbits were divided randomly into 3 groups: simple gunshot-wound group (Group I, n = 10), gunshot wound with seawater immersion for 30 mins (Group II, n = 10), and 60 mins group (Group III, n = 10). Femoral arteries were impacted by 0.38 g steel spheres fired with a 7.62 mm rifle. After being wounded, rabbits in Groups II and III were immersed in seawater for 30 or 60 mins, but those in Group I were not. At 2, 4, 6, 8, 12 hours following injury, a 40 mm segment of the artery on each side of the gunshot point were excised and observed by light and electron microscopy.</p><p><b>RESULTS</b>The patterns of arterial injuries were mainly contusion and transection. Completely transected artery was classified as primary-wound-tract area, contused area and shocked area. Compared with those in Group I, the primary-wound-tract and contused areas in Group II manifested obvious swelling in the arterial wall especially at the outside 2/3 of the media. Vacuolar structures were often seen in smooth muscle cells of the media. Intercellular space among the smooth muscle cells were filled with homogeneous acidophilic substances. Deep rugae among endothelial cells flattened or rugal folds lost their longitudinal orientation, and marked fibrin and platelet deposition were noticed. No significant difference was detected between Group II and III. The pathological changes in the shocked area were similar in 3 groups.</p><p><b>CONCLUSIONS</b>For gunshot wounds concomitant seawater immersion in rabbits' femoral arteries, there was a marked swelling of cells and intercellular space in primary-wound-tract area and contusion area. The influence of these pathological changes on surgical reparation deservers further study.</p>

Surgical treatment for rabbits' femoral arteries subjected to gunshot wounds combining with seawater immersion / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the surgical treatment methods and evaluate the outcome of gunshot wounds combining with seawater immersion in rabbits' femoral arteries.</p><p><b>METHODS</b>One hundred healthy New Zealand white rabbits (either sex, 3.14 kg+/-0.61 kg in weight) were randomly divided into a seawater immersion group (n=50) and a simple injury group (n=50). The unilateral femoral arteries of all the rabbits were injured by 0.38 g steel spheres with velocity of 600-800 m/s fired by a 7.62 mm rifle. The rabbits in the seawater immersion group were immersed in seawater (saline content of 2.54%, pH 8.2-8.4, and at 21 degrees C) for 60 minutes but those in the simple injury group were not. After the injured segment (observed by naked eyes) of the femoral artery was excised, the blood flow restoration was reconstructed by direct end-to-end anastomosis, reversed autogenous venous grafting or cryopreserved arterial allografting, according to the length of the arterial defects. At 24 hours, and 7, 14 and 21 days after operation, the blood flow was examined. Operative exploration was performed for the animals with partly or fully obstructed blood flow. The tissues around the anastomosis sites and the grafts were harvested for pathological observation under a light microscope and an electron microscope.</p><p><b>RESULTS</b>In the rabbits with completely transected injury, the unobstructed rates in the first 3 weeks after operation were 80.00% in the seawater immersion group and 86.67% in the single injury group, and no significant difference was found between the two groups (P>0.1). In the rabbits with arterial contusion injury, the unobstructed rates in the first 3 weeks after operation were 86.67% in the seawater immersion group and 82.35% in the single injury group, and no significant difference was found between the two groups (P>0.1). Most thrombosis occurred in the first operative week. Atypical endothelial cells were detected at the anastomosis sites at the first operative week, and the anastomosis sites were lined with endothelial cells in 3 weeks postoperatively.</p><p><b>CONCLUSIONS</b>During the surgical treatment for gunshot wounds combining with seawater immersion, resection of the grossly-injured artery and routine artery reconstruction can obtain satisfactory outcome. Homologous artery is a kind of vascular graft with certain applied value.</p>

Mandibular distraction osteogenesis in the treatment of obstructive sleep apnea syndrome in children with micrognathia / 中华整形外科杂志

<p><b>OBJECTIVE</b>To evaluate the treatment of obstructive sleep apnea syndrome (OSAS) in children with congenital micrognathia using mandibular distraction osteogenesis and to discuss the advantages and disadvantages of this approach.</p><p><b>METHODS</b>6 patients (4 males, 2 females) had undergone mandibular distraction osteogenesis, 12 distraction devices were placed through extraoral incision for bilateral distraction. The mean age of treatment was 1 year and 9 months (range 4 months to 9 years). Every patient had been evaluated pre and postoperatively with cephalometry. The period of consolidation was 4 - 11 weeks. The period of follow-up was from 2 to 10 months.</p><p><b>RESULTS</b>The average distraction distance was 19.2 mm (range 15 to 25 mm). The osteotomy and distraction processes were smooth in all the cases, the osteogenesis was good, without infection and other complications. The posterior airway space was increased from averaged 4.5 mm preoperatively to 10. 1mm after surgery. Five children had normal respiration and sleep restored with naso-pharyngeal airway removal or tracheostomy decannulation. One patient is to receive a planned second stage of distraction with a horizontal vector. The results were stable without relapse during a follow-up period of 2 to 10 months.</p><p><b>CONCLUSIONS</b>Application of mandibular distraction osteogenesis is an important component and effective in the treatment of OSAS and permits mandibular advancement in the younger child. As more experience is gained with distraction osteogenesis in the treatment of children with OSAS, the role of distraction will become better defined.</p>

Surgical management of craniomaxillofacial fibrous dysplasia / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the method to obtain good aesthetic and functional results in surgical management of craniomaxillofacial fibrous dysplasia and correct the grotesque deformity.</p><p><b>METHODS</b>According to the type of the lesions, different excision and reconstruction methods were used.</p><p><b>RESULTS</b>19 cases (4 monostotic cases and 15 polyostotic cases) were surgically treated. The period of follow-up range from 9 months to 5 years, all patients obtained satisfactory aesthetic and functional results. No relapse happened during follow up.</p><p><b>CONCLUSIONS</b>Based on modern craniomaxillofacial techniques and computer aided design, extensive radical excision and craniomaxillofacial skeleton reconstruction could be safely accomplished, and the better results were obtained, both aestheticly and functionally.</p>

Protective role of glycyrrhizin on experimental obstructive nephropat hy in rats / 第三军医大学学报

Objective　To investigate the protective role of glycyrrhizin on experimental obstructive nephropathy in rats. Methods 　The model of obstructive nephropathy was induced by unilateral uretera l ligation in rats and the animals were sacrificed at 12 h and 3,14,28,56 d resp ectively after operation. Specimens were taken from the cortex of kidney. In re nal stroma, routine morphological examinations and counts of karyocyte were made , the expression of collagen type Ⅰand type Ⅲ were also detected by immunohist ochemical staining,then, semi-quantified by EIG image analysis system. Results　 A progressive fibrosis was observed in renal stroma of the mod el. 12 h after operation, counts of karyocyte increased markedly i n renal stroma in groups of treatment and pretreatment with glycyrrhizin compar ed with that in sham-operation group（P<0.05）,and decreased distinctly compared with that in saline treated group（P<0.01）, but no significant di fference was found between treatment group and pretreatment group（P>0.05） ;3 d after operation, in group treated or pretreated with glycyrrhizin. The e xpression of collagen type Ⅰ increased markedly compared with that in sham-o peration group（P<0.01） in renal stroma, but decreased notably compare d with that in saline treated group（P<0.01）,while, there was not any diffe rence between treatment group and pretreatment group（P>0.05）. The expressi on of collagen type Ⅲ in renal stroma was almost the same as that of coll agen type Ⅰ. Conclusion　Glycyrrhizin has some therapeutical bu t no preventive effect to experimental obstructive nephropathy in rats.

Surgical management and its therapeutic effect of gunshot wounded femor al arteries immered in seawater in rabbits / 第三军医大学学报

Objective　To investigate the surgical management of a gun shot wound of blood vessels and immersied, and evaluate its primary effect. Methods　100 rabbits were divided randomly into simple wounded group(SWG,n=50) and seawater immersion group(SIG,n=50).F emoral arteries were impacted by 0.38 gram steel spheres with velocity of 600 ～800 meters per second fired by 7.62 mm rifle. Animals in SIG were immersed in artificial seawater (pH 8.2～8.4, salinity 25.4,temperature 21℃) for 60 min, o f which those in SWG were spared. Grossly injuried artery was excised and restor ation of blood flow was reconstructed by end-to-end anastomosis or reversed au togenous venous grafting or cryopreserved arterial allografting. At 24 h,7,1 4,21 days after operation, blood flow was examined by Doppler ultrasonic detecti on and part of anastomotic sites and graft were collected for pathological obser vation. Results　In completely transected injury, the patency in SIG was 80.00%,while that in SWG was 86.67% in the first 3 weeks. In arterial c ontused injury ,patency in SIG was 86.67%,and that in SWG was 82.35% at the same time. Thrombosis occurred mostly in the first postoperative week. Atypical endo thelial cells were found at the anastomosis sites in the first postoperative week, and the anastomosis sites were lined with endothelium in 3 weeks postopera tively. Conclusion　Early curative effect could be obtained. Whe n grossly injuried artery is excised and followed by a routine surgical procedur e in the treating gunshot wounds immersed in seawater.

Cold-stress stimulates pregnancy-induced hypertension syndrome in pregnant rats / 第三军医大学学报

Objective　To determine whether cold-stress stimulation could lead to pregnancy-induced hypertension syndrome (PIH) in rats. Methods　Female adult Wistar female rats were randomly divided into 4 groups: non-pregnant control group (NN), non-pregnant cold-stress group (NC), pregnant control group (PN) and pregnant cold-stress group (PC). The rats were kept in (4±2) ℃ for 4 h (cold-stress groups) every day or remained in 25 ℃ (control groups) from the 1 st day to 19 th day of pregnancy. The blood pressure, urine protein, body weight, haematocrit (HCT), weight of placenta, length and weight of fetus were all measured. The histological change of the placenta and kidneys were also observed. Results　After cold-stress stimulation for 2 weeks, the blood pressure, urine protein in NC and PC group increased significantly compared with that in control group, while the weight of placenta and fetus, the length of fetus in PC decreased significantly than that in PN. Obvious ischemic and anoxic histological changes in kidneys and all layers of placenta were found in PC group. Conclusion　Repeated cold-stress stimulation can induce PIH in rats, thus provide a new non-invasive method to establish an animal model of PIH.

Study on the evaluation of the execution of super high velocity fragment / 第三军医大学学报

Objective　To provide experimental basis for the weapon design by means of observing the injury by super high velocity fragments. Methods　Nine male Huanan dogs were wounded by super high velocity aluminium bullet shot from an explosive gun with the energy of 15 360,12 643 and 8 144 J respectively, the degree of injury of local tissues and the pathological changes of main organs were observed. Results　The injury degree of local tissue wounded by the super high velocity fragment of 15 360 J was similar to that of 8 144 J, and was more severe than that of wound by 12 643 J. Conclusion　The injury degree is closely related to the mass and the momentum of the super high velocity fragment, the more the momentum is,the greater the execution is. No significant relationship exist between the injury degree and the energy.

Protective role of glycyrrhizin on experimental obstructive nephropat hy in rats / 第三军医大学学报

Objective　To investigate the protective role of glycyrrhizin on experimental obstructive nephropathy in rats. Methods 　The model of obstructive nephropathy was induced by unilateral uretera l ligation in rats and the animals were sacrificed at 12 h and 3,14,28,56 d resp ectively after operation. Specimens were taken from the cortex of kidney. In re nal stroma, routine morphological examinations and counts of karyocyte were made , the expression of collagen type Ⅰand type Ⅲ were also detected by immunohist ochemical staining,then, semi-quantified by EIG image analysis system. Results　 A progressive fibrosis was observed in renal stroma of the mod el. 12 h after operation, counts of karyocyte increased markedly i n renal stroma in groups of treatment and pretreatment with glycyrrhizin compar ed with that in sham-operation group（P<0.05）,and decreased distinctly compared with that in saline treated group（P<0.01）, but no significant di fference was found between treatment group and pretreatment group（P>0.05） ;3 d after operation, in group treated or pretreated with glycyrrhizin. The e xpression of collagen type Ⅰ increased markedly compared with that in sham-o peration group（P<0.01） in renal stroma, but decreased notably compare d with that in saline treated group（P<0.01）,while, there was not any diffe rence between treatment group and pretreatment group（P>0.05）. The expressi on of collagen type Ⅲ in renal stroma was almost the same as that of coll agen type Ⅰ. Conclusion　Glycyrrhizin has some therapeutical bu t no preventive effect to experimental obstructive nephropathy in rats.

Surgical management and its therapeutic effect of gunshot wounded femor al arteries immered in seawater in rabbits / 第三军医大学学报

Objective　To investigate the surgical management of a gun shot wound of blood vessels and immersied, and evaluate its primary effect. Methods　100 rabbits were divided randomly into simple wounded group(SWG,n=50) and seawater immersion group(SIG,n=50).F emoral arteries were impacted by 0.38 gram steel spheres with velocity of 600 ～800 meters per second fired by 7.62 mm rifle. Animals in SIG were immersed in artificial seawater (pH 8.2～8.4, salinity 25.4,temperature 21℃) for 60 min, o f which those in SWG were spared. Grossly injuried artery was excised and restor ation of blood flow was reconstructed by end-to-end anastomosis or reversed au togenous venous grafting or cryopreserved arterial allografting. At 24 h,7,1 4,21 days after operation, blood flow was examined by Doppler ultrasonic detecti on and part of anastomotic sites and graft were collected for pathological obser vation. Results　In completely transected injury, the patency in SIG was 80.00%,while that in SWG was 86.67% in the first 3 weeks. In arterial c ontused injury ,patency in SIG was 86.67%,and that in SWG was 82.35% at the same time. Thrombosis occurred mostly in the first postoperative week. Atypical endo thelial cells were found at the anastomosis sites in the first postoperative week, and the anastomosis sites were lined with endothelium in 3 weeks postopera tively. Conclusion　Early curative effect could be obtained. Whe n grossly injuried artery is excised and followed by a routine surgical procedur e in the treating gunshot wounds immersed in seawater.

Cold-stress stimulates pregnancy-induced hypertension syndrome in pregnant rats / 第三军医大学学报

Objective　To determine whether cold-stress stimulation could lead to pregnancy-induced hypertension syndrome (PIH) in rats. Methods　Female adult Wistar female rats were randomly divided into 4 groups: non-pregnant control group (NN), non-pregnant cold-stress group (NC), pregnant control group (PN) and pregnant cold-stress group (PC). The rats were kept in (4±2) ℃ for 4 h (cold-stress groups) every day or remained in 25 ℃ (control groups) from the 1 st day to 19 th day of pregnancy. The blood pressure, urine protein, body weight, haematocrit (HCT), weight of placenta, length and weight of fetus were all measured. The histological change of the placenta and kidneys were also observed. Results　After cold-stress stimulation for 2 weeks, the blood pressure, urine protein in NC and PC group increased significantly compared with that in control group, while the weight of placenta and fetus, the length of fetus in PC decreased significantly than that in PN. Obvious ischemic and anoxic histological changes in kidneys and all layers of placenta were found in PC group. Conclusion　Repeated cold-stress stimulation can induce PIH in rats, thus provide a new non-invasive method to establish an animal model of PIH.

Study on the evaluation of the execution of super high velocity fragment / 第三军医大学学报

Objective　To provide experimental basis for the weapon design by means of observing the injury by super high velocity fragments. Methods　Nine male Huanan dogs were wounded by super high velocity aluminium bullet shot from an explosive gun with the energy of 15 360,12 643 and 8 144 J respectively, the degree of injury of local tissues and the pathological changes of main organs were observed. Results　The injury degree of local tissue wounded by the super high velocity fragment of 15 360 J was similar to that of 8 144 J, and was more severe than that of wound by 12 643 J. Conclusion　The injury degree is closely related to the mass and the momentum of the super high velocity fragment, the more the momentum is,the greater the execution is. No significant relationship exist between the injury degree and the energy.