The aim of this paper is to explore the prevention of rabbit postoperative abdominal cavity adhesion with poly (lactic-co-glycotic acid) (PLGA) membrane and the mechanism of this prevention function. Sixty-six Japanese white rabbits were randomly divided into normal control group, model control group and PLGA membrane group. The rabbits were treated with multifactor methods to establish the postoperative abdominal cavity adhesion models except for those in the normal control group. PLGA membrane was used to cover the wounds of rabbits in the PLGA membrane group and nothing covered the wounds of rabbits in the model control group. The hematologic parameters, liver and kidney functions and fibrinogen contents were detected at different time. The rabbit were sacrificed 1, 2, 4, 6, 12 weeks after the operations, respectively. The adhesions were graded blindly, and Masson staining and immunohistochemistry methods were used to observe the proliferation of collagen fiber and the expression of transforming growth factor β1 (TGF-β1) on the cecal tissues, respectively. The grade of abdominal cavity adhesion showed that the PLGA membrane-treated group was significant lower than that in the model control group, and it has no influence on liver and kidney function and hematologic parameters. But the fibrinogen content and the number of white blood cell in the PLGA membrane group were significant lower than those of model control group 1 week and 2 weeks after operation, respectively. The density of collagen fiber and optical density of TGF-β1 in the PLGA membrane group were significant lower than those of model control group. The results demonstrated that PLGA membrane could be effective in preventing the abdominal adhesions in rabbits, and it was mostly involved in the reducing of fibrinogen exudation, and inhibited the proliferation of collagen fiber and over-expression of TGF-β1.
Abdominal Cavity ; surgery ; Animals ; Collagen ; metabolism ; Lactic Acid ; Polyglycolic Acid ; Rabbits ; Tissue Adhesions ; prevention & control ; Transforming Growth Factor beta1 ; metabolism

Objective To provide an experimental reference for clinic application of Jiazhu vascular ligating clips on ligation effects and the impact on the body in rabbits after laparoscopoic cholecystectomy.Methods 36 rabbits were randomly divided into 3 groups, normal control group, Jiazhu group and similar product control ( Hem-o-lok) group, 12 rabbits in each group.Except for normal control group, the rabbits were used gallbladder duct and gallbladder artery closed by vascular ligating clips and Hem-o-lok clips in Jiazhu group and similar product control group, respectively.The changes of blood biochemical, electrolytes, hematological parameters, coagulation, ligation effects and organ coefficients were observed at post-operation during 12 months.Results Compared with normal control group, the rabbit weight was reduced in the Jiazhu group at 3 days postoperatively ( P <0.01 ) , ALT level was increased at 1week postoperatively ( P <0.05), CREA and ALB levels were all significant decreased at 1~2 weeks postoperatively (P <0.05, P <0.01), NEUT numbers and TG content were significant increased at 2 weeks postoperatively ( P <0.05 ) , GLU content was significant decreased at 2 weeks and 1 month postoperatively ( P <0.01 ); LYM and RBC numbers were significant decreased at 1 month and 1 week postoperatively (P <0.05), respectively.PLT numbers were significant increased at 1~2 weeks postoperatively ( P <0.01) .While the rabbit weight was reduced in the Hem-o-lok group between 3 days and 1month postoperatively (P <0.05, P <0.01), and ALT level, NEUT and PLT numbers were increased at 1 week postoperatively (P <0.05, P <0.01), ALB and GLU contents were all significant decreased at 2 weeks postoperatively (P <0.01), TC content was significant increased at 1~2 weeks postoperatively (P <0.05).The rabbit weight, blood biochemical and hematological parameters in the Jiazhu group and Hem-o-lok group were all no significant differences with normal control group in the remaining time ( P >0.05 ) , and there were all no significant differences with electrolyte, coagulation and organ coefficients between each group (P >0.05).Conclusion Jiazhu vascular ligating clips are safe and reliable to close gallbladder duct and blood vessels, It shows that there are no differences in the validity and security between Jiazhu vascular ligating clips and Hem-o-lok clips.

Objective To establish a rabbit model of facial skin lifting and to evaluate the skin lifting effects of absorbable soft tissue plastic belt, and to provide experimental basis for clinical application of this plastic belt.Methods 36 Japanese white rabbits were randomly divided into model control group (n=6) and plastic belt lifting group (n=30). The model control group received only facial skin resection surgery, while the plastic belt lifting group had facial skin resection and plastic belt implantation.The changes of rabbit general status, skin lifting effects, performance of plastic belt and pathological changes of subcutaneous tissue after implantation were determined during the 4 weeks after surgery. Results The rabbit skin wound was healed within 3-7 days after surgery without infection.Meanwhile, the plastic belts did not show shifting or rupture, and only whitening around the perforations was observed in the two groups.Compared with the model control group, the MA and MB distances in the plastic belt lifting group were significantly lower ( P<0.01 ) , while the biological tension of plastic belts in the facial skin lifting rabbit models was significantly increased with the extension of time after implantation (P<0.01), and the biological tension was 18.62 N at 4 weeks after transplantation. In addition, the tensile intensities of perforations and plate in the two groups were significantly reduced at 4 weeks postoperatively (P<0.01), the tensile intensity of perforations and plate in the two groups were maintained at 35.07 N and 53.31 N, respectively, and the perforations/plate tensile intensity ratio of the two groups remained unchanged during 4 weeks after transplantation ( P >0.05 ) .Moreover, the molecular weight ( Mw ) , peak molecular weight ( Mp ) , Z molecular weight (Mz) and viscosity were gradually decreased along with the time passing after implantation (P<0.01), and its dispersion Mz/Mw ratio was also gradually decreased from 2 weeks after implantation (P<0.01), and no obvious pathological changes were found after subcutaneous implantation of the plastic belts.Conclusions We have successfully established a facial skin lifting rabbit model, and the plastic belt can obviously lift the facial skin fascia system and keep intact more than 4 weeks in the body.Therefore, this plastic belt can be applied for anti-wrinkle facial soft tissue lifting against the skin damage caused by aging.

OBJECTIVETo investigate the effects of PLGA absorbable membrane in prevention of postoperative abdominal adhesion in rabbits.

METHODS66 Japanese white rabbits were randomly divided into three groups: the normal control group n = 6, model control group n = 30 and PLGA group n = 30. Rabbits were received multifactor methods to establish postoperative abdominal adhesion models except for normal control group. The cecum wound was covered PLGA membrane in the PLGA group. At postoperative 1, 2, 4, 6 and 12 weeks, the abdominal cavities were reopened and the adhesive severity was graded blindly, and the hydroxyproline level in cecum tissue was measured and the cecum histopathology was observed.

RESULTS(1) the degree of adhesion and hydroxyproline level in model control group were significantly higher than those of normal control group (P < 0.05, P < 0.01), while the degree of adhesion and hydroxyproline level in PLGA group were significantly lower than those of model control group (P < 0.05). (2) HE staining showed that cecum serosa had obviously inflammatory cell infiltration and fibroblast proliferation, while PLGA could inhibit fibroblast proliferation and reduce the inflammatory cell infiltration and collagen.

CONCLUSIONPLGA absorbable membrane can inhibit fibroblast proliferation and collagen to prevent the experimental postoperative peritoneal adhesions.

Abdominal Cavity ; pathology ; Animals ; Cell Proliferation ; Collagen ; analysis ; Fibroblasts ; cytology ; Lactic Acid ; chemistry ; Membranes, Artificial ; Polyglycolic Acid ; chemistry ; Postoperative Complications ; prevention & control ; Rabbits ; Tissue Adhesions ; prevention & control

ObjectiveTo explore the possible peripheral analgesic mechanism of electroacupuncture （EA） at promimal and distal acupoints in treatment of myofascial pain syndrome （MPS）. MethodsTwenty-four SD rats were randomly divided into blank group， model group， proximal group， and distal group， with six rats in each group. MPS model was prepared by “strike combined with centrifugal exercise” in all groups except for the blank group. After modeling， the rats in the proximal group received EA at the local myofascial trigger points （MTrPs）， namely the Ashi points， with dilatational waves of frequency of 2/100 HZ and voltage of 2-4 V， current intensity depending on a slight trembling of the left lower limbs， once a day， 15min each time，for 14 days. The rats in the distal group received EA at “Yanglingquan” （GB 34） and “Yinlingquan” （SP 9）， with the same operations as the proximal group. The rats in the blank group and the model group were only grasped and hedged， without other interventions. After intervention， the paw withdrawl mechanical threshold （PWMT） was measured， and variability between the left and right hind paws was calculated. Musculoskeletal ultrasound imaging and electromyography monitoring were performed on the left lower extremity vastus medialis. The morphological changes of vastus medialis muscle of the left lower extremity were observed by HE staining. The positive expression of substance P （SP）， calcitonin gene-related peptide （CGRP）， CD68 and CD206 in muscle tissue was detected by immunohistochemistry. Abdominal aortic serum interleukin-1β （IL-1β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， interleukin-10 （IL-10）， and interleukin-8 （interleukin-8） were detected by ELISA. ResultsCompared to those in the blank group， the fibers of the vastus medial muscle of the rats in the model group were broken and distorted with thickness in variation， and the myofascia was broken， with fibrillation potential， enlarged muscle cells， inward moved nucleus， and widened muscle space； the variability of PWMT between the left and right hind paws significantly increased， as well as the levels of SP， CGRP， CD68， and CD206 in the vastus medialis muscle （P＜0.01）， and the serum IL-8 and TNF-αlevels were significantly elevated （P＜0.05 or P＜0.01）. Compared to those in the model group， the muscle fibers in the proximal and distal group were complete in shape and arranged in an orderly manner， with continued non-broken myofascia， regular shape of muscle cells， and significantly reduced level of IL-8 （P＜0.01）； the amplitude and frequency of spontaneous discharge in the proximal group significantly decreased， as well as the variability of PWMT between the left and right hind paws， and the levels of SP， CGRP， and CD68 in the vastus medialis muscle， while the CD206 level increased significantly （P＜0.05 or P＜0.01 ）； there was complex discharges in the distal group， with significantly decreased level of CD68 in the vastus medialis muscle and increased level of CD206 （P＜0.01）. Compared to the proximal group， the level of IL-8 in the distal group was significantly higher （P＜0.05）. ConclusionsEA at proximal acupoints can significantly improve the pain threshold and local muscle tissue morpho-logy in rats， and its mechanism may be related to reducing the levels of pain-causing substances and related inflammatory factors and promoting the polarization of macrophages. The analgesic effect of EA at distal acupoints is not obvious， and the mechanism is still unclear.