1.Vascularization in tissue engineering materials for urology
Chinese Journal of Tissue Engineering Research 2007;0(10):-
BACKGROUND: As an important part of tissue engineering, vascularization of compound materials is crucial to the survival of seed cells on scaffolds and the functional recovery of original tissues or organs. OBJECTIVE: To summarize the current development of vascularization in tissue engineering repair and reconstruction for urology. RETRIEVAL STRATEGY: An online search was conducted in PUBMED database and CNKI database to identify the articles related to vascularization in urology published from July 2002 to October 2007 using the of "tissue engineering, vascularization, angiogenesis, omentum, growth factor, endothelial progenitor cell, urethra, bladder, urology" in English or in Chinese. Inclusive criterion: The contents of articles were related to vascularization research in tissue engineering repair and reconstruction for urology. Those repeated studies were excluded. LITERATURE EVALUATION: Totally 214 related papers were collected, and 82 of them met the criteria, including 31 and 25 papers related to the use of omentum and growth factor in tissue engineering for urology respectively, and other 26 articles related to the use of seed cells for vascularization in urinary system. Thirty representative articles were selected as the references. DATA SYNTHESIS: At present, the great omentum has been used as a bioreactor. After being wrapped by the omentum, the tissue engineered ureter or bladder can be seen a well vascularized structure. Some researches have also found when acellular matrix is combined with some growth factors, such as vascular endothelial cell growth factor and basic fibroblast growth factor, the formation of blood capillary on scaffolds can be promoted. Moreover, various seed cells have been used to construct a substitute material by combining with capillary structure. Not only stem cells but also progenitor cells have been considered as a potential to construct microvascularized tissue engineered organs for urology. CONCLUSION: It is certain that vascularization research is one of the focal points of tissue engineering for urology. But the related research just can be used in laboratory. Few reports are used in clinical practice of urology. So many unsolved problems need an exploration.
2.Roles of Hedgehog signaling in T cell differentiation and development
Xiaobing FENG ; Yuemin LI ; Yang LI
Journal of International Oncology 2014;41(11):813-816
The production of mature functional T cells requires many signals from the thymus such as Wnt,Notch and Hedgehog,et al.The Hedgehog protein family signals for development,patterning and organogenesis of many tissues during mammalian embryogenesis.In recent years,more and more research groups focus their attention on it because of its relationship between tumors.Abnormal differentiation and development of T cells may cause various immunological diseases and tumors.Illuminating the roles of Hedgehog signaling in T cell differentiation and development can provide a theoretical guide in the treatment of tumor.
3.Effects of alpha-1-adrenergic receptor subtype-selective antagonists on lower urinary tract function in rats with bladder outlet obstruction
Baojun GU ; Feng LIU ; Yuemin XU
Chinese Journal of Urology 2006;0(S1):-
500 mg,frequency was reduced in rats treated with tamsulosin (P500 mg,and the combined ?1a/?1dAR antagonist tamsulosin reduces urinary frequency more than the ?1aAR selective antagonist 5MU.This finding supports the hypothesis that the ?1dAR is important in mediating irritative symptoms.
4.Biocompatibility of bladder acellular matrix graft after frozen and lyophilized processing
Weidong ZHU ; Yuemin XU ; Chao FENG ; Lei CUI
Chinese Journal of Tissue Engineering Research 2007;0(21):-
BACKGROUND:Bladder acellular matrix graft (BAMG) is frequently used for domains of tissue engineering scaffold due to its great biocompatibility and cell adhesion. OBJECTIVE:To verify the biological characteristics of BAMG after frozen and lyophilized processing. DESIGN,TIME AND SETTING:A biocompatibility experiment was performed at Shanghai Tissue Engineering Research and Development Center and Experimental Animal Department of the Sixth People's Hospital of Shanghai between May and November 2008. MATERIALS:Two New Zealand rabbits were used in this study for BAMG preparation. METHODS:After midsection of rabbit bladder,mucous membrane of urinary bladder was isolated and dipped in three-distilled water for 24 hours. Thereafter,the samples were incubated with acellular solution containing 0.1% Triton X-100 and 0.15% aqueous ammonia for 14 days. The culture medium was changed regularly. The samples in the control group were stored in 75% ethanol,while samples in the experimental group were frozen for 24 hours at -80 ℃,vacuum-dried for 24 hours,and stored in 75% ethanol. MAIN OUTCOME MEASURES:Biological characteristics of BAMG were detected using hematoxylin and eosin staining,Masson staining,and scanning electron microscopy; biological characteristics were compared between the two groups using cell adhesion test,MTT assay,and subcutaneously embedding test. RESULTS:Hematoxylin and eosin staining and Masson staining revealed that no residual cells were detected in the BAMG,and collagen was intact. Scanning electron microscopy demonstrated that cells exhibited a slit-shaped structure mainly containing collagen which was beneficial for cell adhesion. Mechanical test revealed that the BAMG after frozen and lyophilized processing not only reserved the mechanical properties of the raw BAMG,but also had a great elongation. MTT assay confirmed that cytotoxicity was grade 0,and BAMG had a good compatibility to smooth muscle cells. After subcutaneously embedding for one month,BAMGs had good adhesions to subcutaneous tissues,and muscular adhesion and vascular proliferation were observed. CONCLUSION:BAMG after frozen and lyophilized processing reserves original biocompatibility and has great elongation; therefore,it will become a useful and ideal biomaterial for tissue engineering scaffold.
5.Bladder reconstruction with seeding adipose-derived stem cells onto bladder acellular matrix grafts
Weidong ZHU ; Yuemin XU ; Chao FENG ; Qiang FU ; Lujie SONG
Chinese Journal of Urology 2012;33(2):111-116
ObjectiveTo assess the feasibility of seeding adipose-derived stem cells (ADSCs) onto bladder acellular matrix grafts (BAMGs) for bladder reconstruction in a rabbit model.MethodsAutologous ADSCs were isolated,expanded and identified by flow cytometry.In the experimental group,ADSCs were seeded onto BAMGS for reconstructing bladder defects in 12 male rabbits.Unseeded BAMGs were used for bladder reconstruction in the control group of 12 rabbits.Cystography was performed at 24 weeks after grafts implantation.Following cystography,the animals were scarified and grafts were harvested; H&E and immunohistochemical staining were performed with cytokeratin AE1/AE3,smooth muscle α-actin and S-100 markers.ResultsFlow cytometry demonstrated that the ADSCs expressed CD90,CD44,CD105,CD166 and CD34,but not CD45 or CD106.The cells demonstrated good biocompatibility with BAMGs.At 24 weeks,in the experimental group,the reconstructed bladders reached a mean volume of (94.68 ± 3.31 )% of the precystectomy bladder capacity.Complete regeneration of smooth muscle and nerve tissue was evident.Regenerated SMCs,urothelium and nerve cells stained positively for α-smooth muscle actin,AE1/AE3 and S100.In the control group,the mean bladder volume was (69.33 ± 5.05 )% of the pre-cystectomy volume.Histologically,the control group was characterized by multi-layered urothelium without evidence for organized muscle or nerve tissue.Conclusion The tissue engineering bladder constructed by ADSCs and BAMG can be used as an ideal biomaterial to replace and repair the bladder.
6.Selection of procedures in one stage urethroplasty for treatment of the coexistence of urethral stricture in the anterior and posterior urethra
Yuemin XU ; Hong XIE ; Chao FENG ; Jiong ZHANG ; Xiangguo LYU
Chinese Journal of Urology 2016;37(1):43-47
Objective To explore selection of the procedures in one stage urethroplasty for treatment of the coexistence of urethral strictures in anterior and posterior urethra.Methods Between January 2008 and December 2014, a total of 27 patients with coexist strictures simultaneously in anterior urethra and posterior urethra were treated in our hospital.The mean age was 38 years old (ranging 13-83 years old.Stricture etiology was secondary to lichen sclerosus in 2 patients, iatrogenic in 3 and posttraumatic in 22.The mean length of urethral stricture was 11cm (ranging 6-14cm).Two procedures for treatment of anterior urethral stricture, including augmentation of urethroplasty using penile skin flap was performed in 20 patients and augmentation of urethroplasty using lingual mucosa in 7.Three procedures for treatment of posterior urethral stricture, including non-transecting spongiosum end to end anastomosis of the two urethral ends was performed in 3 patients, end to end anastomosis of the two urethral ends was performed in 17 and substitution urethroplasty using different tissues was performed in reminder 7 patients.Of them, pedicle scrotal skin urethroplasty was performed in 2 patients and lingual mucosal graft urethroplasty in 5 patients.Results The patients were mean followed up 2.6 years (ranging 0.545.0 years) with an overall success rate of 88.9% (24 of 27 cases).Complications developed in 3 patients (11.1%).Of the 17 patients with end to end anastomosis, urethral stricture developed respectively 4 and 6 months in 2 patients and voiding well after pedicle scrotal skin urethroplasty.Urethral pseudodiverticulum developed 9 months after pedicle penile flap urethroplasty in another patient and voiding well after urethroplasty.Urethrography showed patent urethra with adequate lumen in the remaining patients and mean urinary peak flows was 21.3 ml/s (ranging 14.2-37.9 ml/s).Conclusions Substitution urethroplasty using penile skin or oral mucosa was more good procedure for anterior urethral stricture during the treatment of the coexistence of urethral stricture in the anterior and posterior urethra.The treatment of posterior urethral stricture was based on the length of the stricture, local condition to make a choice between anastomotic urethral reconstruction and substitution urethroplasty using other tissue.
7.Analysis of different bulbourethral sling procedurnges for treatment of male acquired urinary incontinence
Yuemin XU ; Baojun GU ; Hong XIE ; Zhangshun LIU ; Chao FENG ; Xiaofang FEI
Chinese Journal of Urology 2013;34(11):847-850
Objective To explore the efficacy of different bulbourethral sling procedures in the treatment of male acquired urinary incontinence.Methods A retrospective study of 105 patients with acquired urinary incontinence was performed.The patients underwent 3 different bulbourethral sling procedures under urodynamic monitoring between October 2000 and June 2013.Mean age was 54 years (range 15-81).Urinary incontinence was secondary to post-prostatectomy in 70 patients and posterior urethroplasty in 35.Preoperatively,10 patients were completely urinary incontinence and 95 patients were stress urinary incontinence.Mean duration of urinary incontinence was 3 years (1-12).The surgical techniques were composite device suspension in 54 patients,pedicled rectus abdominalis muscle and fascial flaps suspension in 10 and transobturator sling in 41.Results The patients were followed up for 3-128 months (mean 54 months).The urethral catheter was left in situ for 5-7 days in 103 patients.Of the 103 patients,5 patients were difficulty in voiding but corrected by indwelling of urethral tube for another 1 week in 4 patients and transurethral bladder neck resecting in 1.In the remainder 2 patients,the maximum urethral pressure was 110 and 158 cm H2O (1 cm H2O=0.098 kPa) at the end of surgery and both patients were able to void on day 14 and 21 respectively and achieved complete continence.In this study,complete continence was achieved with good voiding in 74 patients (70.5%),completed control of urination rate was 81,4% (57/70) in group of prostate and 48.6% (17/35) in group of posterior urethroplasty.Twenty-six patients were improved and 5 patients were failed.Conclusion Bulbourethral sling procedure under urodynamic monitoring is an effective option in the treatment of male acquired urinary incontinence,especially for patients of incontinence of post-prostatectomy.
8.Selection of procedures for the treatment of female low urovaginal fistulas
Yuemin XU ; Yinglong SA ; Qiang FU ; Hong XIE ; Jiong ZHANG ; Chao FENG
Chinese Journal of Urology 2013;34(10):760-766
Objective To evaluate the selection and outcome of procedures for the treatment of female patients with low urovaginal fistulas.Methods Between Jan.1999 and Dec.2012,a total of 94 low urovaginal fistula patients with mean age 28(5-58)years and the duration of the condition for mean 4(1-23)years were treated using a variety of procedures.Of the 94 patients,the etiology was trauma in 57 patients,iatrogenic injuries in 34,local inflammation in 2 and congenital in 1.Urethral stricture was associated with urethrovaginal fistulas in 61 patients(Group of urethra)and vesicovaginal fistula in 33 (Group of bladder).Of the group of urethra,it was associated with ileovaginal fistula in 2 patients,rectovaginal fistula in 3 and veginal strictures in 8.Of the group of bladder,the fistula was simple or incipient in 15 cases and complex or recurrent in 18 cases.In group of urethra,pedicle labial skin grafs urethroplasty was used in 30 cases,island flap of vulva urethroplasty in 4 cases,vaginal wall flap urethroplasty in 18 cases,end to end anastomotic urethroplasty in 6 cases,and anterior bladder flap uretbroplasty in 3 cases.At the same time of urethroplasty,bladder neck reconstruction was performed in 6 cases with pre-existing traumatic sphincter incompetence,intestovaginal fistula repair was performed in 5 cases.In the group of vesicovaginal fistula,the fistula repairing was performed by transabdominal approach in 18 cases and by transvaginal approach in 15 cases.Results There were no serious complications postoperatively.Patients were followed up with mean 45(5-140)months.Of the 34 cases underwent pedicle labial or an island flap of vulva urethroplasty,fistulas was recurrent in 3 cases and urethral strictures was happened in one case,3 cases had frequent and stress incontinence,however,all 3 cases achieved urinary continence in 3-8 months postoperatively;of the 18 cases underwent urethroplasty using vaginal flap repairs,all patients achieved anatomical success,and continence in 15 patients and stress incontinence in 3 patients;of the 6 patients underwent urethral end to end anastomosis,all patients achieved urethral anatomical repair success and the continence was achieved in 5 patients,stress incontinence in one patient;and the left 3 patients underwent bladder anterior wall urethroplasty,urethral anatomical repair success was in all 3 patients and continence in one,stress incontinence in one and dysuria in one.Endoscopic resection was performed in the patient with voiding difficulty,after which the patient could void smoothly.In the group of urethra,successful urethral anatomical recovery rate was 91.8%(56/61)and successful functional recovery rate was 83.6%(51/61).In the group of bladder,the fistulas were successfully repaired by one procedure in 29 patients(87.9%)and recurrence in 4 patients.Conclusions The selection of procedures for treatment of female patients with low urovaginal fistulas should be determined by stricture characteristics,including location,length and vaginal condition.It is very important to prevented fistulas reformation during operation by using tissue flaps as a bulk.
9.A preliminary investigation of constructing tissue engineering urethral graft using human lingual keratinocyes and natural derived scaffold
Chao FENG ; Yuemin XU ; Qiang FU ; Yinglong SA ; Chao LI ; Weidong ZHU ; Jie LIU ; Lei CUI
Chinese Journal of Urology 2011;32(10):695-699
Objective To investigate the feasibility of constructing tissue engineering urethral substituted graft using human lingual keratinocytes and natural derived scaffold.Methods From Oct.2009to Jan.2010,ten patients with anterior urethral stricture were enrolled in this study.A 0.5 × 0.8 cm lingual mucosa was harvested during the operation.Lingual keratinocytes were then isolated and cultured from the mucosa.AE1/AE3 antibody was used to identify the lingual keratinocytes.Keratinocytes were collected and seeded onto three types of scaffold including dehydrated BAMG,liquid stored BAMG and 4-layer SIS product,with the density of 1 × 107/ml at passage three.After being cultured for seven days in vitro,H&E staining and Electronic Scan Microscopy were used to evaluate the compound matrixes.Results No complication occurred in the patients after operation.The primary passage of confluence lingual keratinocytes appeared in a typical cobblestone shape after being cultured for 14 days in vitro.The proliferation rate of these cells increased rapidly during the three passages.However,it decreased significantly in the 4th passage.H&E and Electronic Scan Microscopy examinations showed that few cells grew on the surface of the liquid stored BAMG.Nevertheless,multiple keratinocytes layers could be seen in dehydrated BAMG and 4-layer SIS.Meanwhile,cellular infiltration could be observed in SIS sections.Conclusions Human lingual keratinocytes could be the alternative of seeding cells for constructing tissues for engineering the urethra.These cells exhibited good compatibility and are adhesive to the SIS or BAMG.The compound matrix,which used human lingual keratinocytes and natural derived scaffold,may meet the clinical need of urethral disease in the future.
10.Use of small intestinal submucosa graft for the repair of anterior urethral strictures
Yuemin XU ; Jiong ZHANG ; Qiang FU ; Yinglong SA ; Lujie SONG ; Chao FENG
Chinese Journal of Urology 2011;32(6):419-422
Objective To investigate the feasibility of using small intestinal submucosa (SIS) graft for the repair of anterior urethral strictures. Methods From June 2009 to August 2010, 18 men (mean age, 38 yrs) with anterior urethral strictures underwent urethroplasty using a four-layer SIS as an onlay patch graft. SIS was used to augment the urethral caliber at the stricture site. The mean stricture length was 4.6 cm (range 3.5 to 7 cm). The pre-operative mean maximal flow rate was 3.8 ml/s (range 1.5 to 5.5 ml/s). The required SIS grafts (4 to 7.5 cm long and 2 cm wide) were positioned into the urethrotomy defect and were spread-fixed to the corpora cavernosa using 5-0 polyglactin interrupted sutures. Two apices of the graft were sutured to the proximal and distal apices of the urethrotomy with 5-0 polyglactin interrupted stitches. The margins of the opened urethra were sutured to the SIS patch with 5-0 polyglactin running sutures. Results The mean follow-up period was 10 mon. (range 6-18 mon.). No postoperative complication, such as infection or rejection related to the use of heterologous graft material was observed. Seventeen patients voided well postoperatively with the mean peak urine flow of 25.4 ml/s (14-44 ml/s). Cystoscopy revealed that at four weeks and six weeks, the SIS graft was well distinguishable from the normal surrounding tissue; and at 16 weeks, the urothelium was regenerated and the biomaterial was not distinguishable from the normal surrounding tissue. The squamosal epithelium was seen in the histological examination of the grafts. The remaining one patient with failed hypospadias developed a slight urethral narrowing at five months post-operatively and needed sound dilatations. Conclusions SIS matrix appears to be a safe and effective reconstructive material in selected urethral reconstructions.