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.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.
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.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.
7.Long-term efficacy of penile skin flaps for reconstruction of anterior urethral stricture
Hong XIE ; Yuemin XU ; Qiang FU ; Yinglong SA ; Jiong ZHANG ; Chao FENG ; Lujie SONG
Chinese Journal of Urology 2014;35(9):681-685
Objective To evaluate the long-term efficacy of using penile skin flaps for urethroplasty in the treatment of anterior urethral strictures.Methods Between Jan 2006 and Dec 2012,138 patients with anterior urethral stricture were treated by using penile skin flaps for urethroplasty.The mean age was 38 years (range,7-82 year).The etiology of stricture included trauma in 78 cases,iatrogenicity in 41 cases,infection in 17 cases,unknown reason in 2 cases.The penile urethral stricture was found in 110 cases and the bulbourethral stricture was found in 28 cases.The mean length of anterior urethral stricture was 6.5 cm (range 3-14 cm).Among them,the length of urethral stricture was more than 10 cm in 48 patients.Basing on location,length of stricture and condition of penile skin,different penile skin flaps were chosen,including vertical pedicle skin flap,pedicle circular flap,L-flap,Q-flap.Three different techniques were used for urethroplasty,such as lateral patch flap urethroplasty (group1,n=80),dorsal and ventral inlaid flap urethroplasty (group 2,n =42) and tubularized flap urethroplasty (group 3,n =16).Results 4 patients were lost during follow-up.The mean duration of follow-up in the remaining 134 patients was 39 months (range,8-84 months).Complications developed in 29 of 134 patients (21.6%),including strictures recurrence in 17 (group 1,n =12,group 2,n=2 and group 3,n =3),urethrocutaneous fistulas in 7 (group 1,n =5,group 2,n=1 and group 3,n =1) and urethral diverticulum in 5 (group1,n =4,and group 3,n =1).105 cases voided well and the urinary peak flows ranged from 13-49 ml/s (mean 25 ml/s),The overall success rate was 78.4% (105/134).Conclusions Penile skin is thinner,rich in blood supply and easy to be manipulated,which is one of the excellent materials for the urethral reconstruction.Q-flap or L-flap urethroplasty is an effective technique for the treatment of long-segment urethral strictrues (≥ 10 cm).
8.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.
9.Serous-lined tunnel technique in urinary reconstruction
Baojun GU ; Haruaki KATO ; Feng LIU ; Ting SHEN ; Denglong WU ; Sanbao JIN ; Yong QIAO ; Yuemin XU
Chinese Journal of Urology 2010;31(5):347-349
Objective To examine the feasibility of using the serous-lined tunnel technique for orthotopic neobladder, continent cutaneous diversion and ureteral replacement by the intestinal segment. Methods In 31 patients of orthotopic ileal neobladder, the serous-lined tunnel techniques were used for antirefluxing ureteral implantation: In 13 patients of continent ileal pouch, the techniques were adopted for continent-valve construction and for uretersl implantation: In 3 patients (with lower ureteric cancer), the same techniques were applied for constructing the ileal ureters with a proximal antirefluxing mechanism. Results With a mean follow-up of 27 mon( 12-132 mon), 88 ureters implanted into ileal neobladders or continent pouches functioned well with neither obstruction nor reflux: 12 in 13 continent valves functioned well with no incontinence. 3 patients with ileal ureters showed no ileo-ureteric reflux and had reduced hydronephrosis comparing to that of before surgery.Conclusions Ureteral reimplantation and continent valve formation achieved by adopting the serouslined tunnel technique provide satisfactory results. The versatility of the technique is obvious in the present experience and the creative application of the serous-lined tunnel technique should be possible in urinary reconstruction.
10.The efficacy of construction of neourethra using a bladder anterior wall for treatment of female total urethral stricture or atresia
Yuemin XU ; Hong XIE ; Xiangguo LYU ; Hui GUO ; Chao FENG ; Hongbin LI
Chinese Journal of Urology 2016;37(8):603-606
Objective To explore the efficacy of constructing the neourethra using a bladder anterior wall for the treatment of female total urethral stricture or atresia.Methods We retrospectively reviewed 11 female patients with total urethral stricture or oblitalition,who were underwent a procedure of reconstructive neourethra using a bladder anterior wall,from January 2009 to November 2015.Of the 11 patients,urethral stricture was associated with vesicovaginal fistula and a severe hydrocolpos in the proximal vagina because of vaginal anterior strictures or atresia in four girls.The mean age was 16 years (ranging 5-48 years) in all patients.The etiology was posttraumatic urethral injuries after pelvic fracture in 9 patients,radical urethral resection because of urethral cancer in 1 patient and congenital bladder exstrophy with an absent urethra in 1 patient.All patients underwent a procedure of neourethral construction under general anesthesia.The bladder anterior wall,which was about 2.0 to 2.5 cm in width and 4.0 ~4.5cm in length,was separated from bladder neck to middle partion of the anterior bladder wall.The bladder flap was tubularized around a 12-14 French catheter using continuous 4-0 polyglycolic acid sutures for the mucosa and interrupted sutures of 3-0 polyglycolic acid for the muscle.The tubularized flap was then flipped caudally to the site of the original external urethral meatus to form a new urethra.4 patients with severe stenosis or oblitalition of the distal vagina underwent a procedure of vaginoplasty at same time,including island vulvar flaps enlarging vaginoplasty in two girls and reconstructive vaginal orifice using the proximal enlargedvagina wall in other two girls.Results There were no serious complications postoperatively.The catheter was removed 3 ~4 weeks after the operation.7 patients were completely continent with excellent voiding,3 patients had stress incontinence.One patient experienced dysuria.And the urethroscopy in this case showed that the mucosal prolapse was present at the 12 to 3 o'clock position on the neck of the bladder,which caused urinary obstruction.Endoscopic resection of the prolapsed mucosa was performed.The patient could easily void without incontinence after the operation.The patients were followed up a median of 38 months,(ranging 6-72 months).2 patients experienced dysuria 3 and 4 months after operation,separatively.Examination showed that the mucosal prolapse was present at the position on the neck of the bladder in one patient and urethral meatal stenosis in another patient.The two patients were separatively underwent a procedure of endoscopic resection of the prolapsed mucosa and meatal urethroplasty,using vulvar flap.All of them could easily void without incontinence after the operation.Of the 3 patients with stress urinary incontinence,one underwent a procedure of TVT-O one year later,and after which continence was achieved with good voiding;the other two cases were awaiting for reoperation.Four cases of postoperative vaginal fluid disappeared with unobstructed micturition.Conclusions Female neo-urethral reconstruction using the bladder anterior wall flap was a reliable technique for the management of complete urethral stricture or obliteration.