| Part ?:Quantitative Analysis of MMP-2,TIMP-2 and Biomechanical Changes in Scar Hypertrophy after Autologous Free Transplantation of Rabbit Oral Mucosa and Scrotal SkinObjectiveTo investigate the long-term scar hypertrophy in the rabbit transplanted oral mucosa and scrotal skin with changed matrix environment,as well as the scar location expression,quantitative analysis of matrix metalloproteinase-2(MMP-2)and tissue inhibitor of metalloproteinase-2(TIMP-2)and biomechanical changes in the transplanted tissues,so as to provide basic experimental foundation for the clinical application of mucosa in repairing urethral defect.MethodsThe split-thickness skin grafts were collected from the oral mucosas and scrotal skins of 21 male rabbits,and prepared into reelpipes for autologous transplantation into the rabbit back muscular tissues.Samples were collected at 0,2,4,8,16,20 and 24 weeks after surgery to carry out elastic tensile mechanical detection and histological observation(HE staining and immunohistochemical IHC assay);besides,the integral optical density(IOD)and areas of MMP-2 and TIMP-2 were measured based on IHC results.Finally,the average optical density(AOD)was calculated to quantitatively analyze the protein expression differences of MMP-2 and TIMP-2.ResultsAt the first 8 weeks after transplantation,the longitudinal tensile change per mm of the oral mucosa was 0.96±0.30 mm,while that of the scrotal skin was 0.82±0.51 mm,and the difference between two groups was not statistically significant(P>0.05).The maximum longitudinal tensile displacement of the oral mucosa before and after 8 weeks of transplantation was not markedly declined(P>0.05),while that of scrotal skin before 8 weeks of transplantation(0.82±0.51 mm)was greater than that after 8 weeks of transplantation(0.46±0.15 mm)(P<0.05).The expression intensities of MMP-2 and TIMP-2 in the oral mucosa at Tzw time point(0.175±0.038;0.176±0.034)were higher than those at To time point(0.075+0.009;0.094±0.0156)(P<0.05);while those in scrotal skin at T2w time point(0.169±0.023;0.171±0.012)were also higher than those at To time point(0.075±0.009;0.094±0.0156)(P<0.05).The expression quantities of TIMP-2 in oral mucosa and scrotal skin during Tsw-T24w were higher than those of MMP-2(P<0.05).At T8w time point,the TIMP-2/MMP-2 ratio[2.25(2.11,2.36)]in scrotal skin was higher than that in oral mucosa[1.55(1.45,1.61)](P<0.05).ConclusionsThe maximum elastic tensile displacement and changes per mm of the transplanted tissue before and after surgery can be obtained through elastic mechanical detection of the transplanted oral mucosa and scrotal skin.At the same time,long-term scar hypertrophy can result in the declined elastic tensile capacity of the transplanted tissue MMP-2 and TIMP-2 expression in normal oral mucosa and scrotal skin is weak,but their expression is remarkably up-regulated after 2 weeks of transplantation,revealing that scar formation was related to the high expression of MMP-2 and TIMP-2.At the 8th-24th weeks,the AOD values of TIMP-2 in oral mucosa and scrotal skin are apparently higher than those of MMP-2;moreover,the TIMP-2/MMP-2 ratio in scrotal skin at the 8th week was higher than that in oral mucosa,which can well explain the earlier scar formation in scrotal skin than in oral mucosa,and it also suggests that the different expression levels between TIMP-2 and MMP-2 may account for the important cause of scar formation.Part ?:Plastic Surgery for Congenital Hypospadias in InfantsBackgroundThe early repair of hypospadias can only solve the problem of standing micturition.With the improvement and progress of modern medicine and quality of life,doctors and patients are paying more and more attention to the problems such as the shape of penis,smooth degree of inner wall of urethra,residual urine and semen in urethra,and whether the reconstructed urethra has contractive function,the secondary deformity of hypospadias and the satisfaction of patients with sexual function At present,the domestic and foreign doctors have not reached an agreement on the time to accept surgeries and clinical indicators,especially the functional indicators,of the surgical repair of hypospadias.In order to improve the problem of the insufficient compliance and motivation of the reconstruction of urethra in hypospadias,it is necessary to further explore the possibility of the smooth muscle component of scrotum dartos to model the contractive function of the corpus spongiosum,and for the early patients undergoing the repair of hypospadias Children,with the growth and development of hypospadias after surgery secondary deformities were summarized and analyzed.Clinical significance of reconstruction of functional urethra with staged buccal mucosa and scrotal skin flapsObjectivesTo discuss the possibility and clinical significance of functional urethra reconstruction with staged buccal mucosa and scrotal skin flaps in the repair of hypospadias in infants.MethodsIn the first stage,the urethral wall was reconstructed with an oral mucosa reelpipe,and in the second stage,after urethral anastomosis,the reconstructed urethra was covered with the scrotal skin flap to form a composite tissue urethra.Six months after operation,ultrasound was used to detect residual urine,semen and electromyogram(EMG)to detect the contractility and compliance of the reconstructed urethra in the process of urination.ResultsAmong 163 cases,in addition to 25 patients with infection and 24 patients with distal blood supply obstruction of scrotal flap causing urinary fistula during hospitalization,antibiotic treatment was given after operation and kept local perineum clean,18 patients healed spontaneously without surgeries within one month after operation,6 patients returned to our hospital half a year later for urinary fistula repair,no recurrence of urinary fistula was found after operation.The rest of patients had no urethral stricture or fistula,no residual urine or semen in the urethra,and good urination and voiding rangeConclusionsIn the first stage,an oral mucosa reelpipe was used to form the urethral wall,and in the second stage,the scrotal skin flap was used to cover the reconstructed urethra to form a composite tissue urethra.The urethral wall was smooth without hair and had good compliance.Because of the existence of scrotal smooth muscle tunica dartos tissue flap,it had good contractility.EMG showed that scrotal tunica dartos muscle could effectively contract at the end of urination and make residual urine and residual excrete.Scrotal smooth muscle tunica dartos tissue flap has certain function. |
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