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.Studies on effect of artemether to control infection and prevent acute infection of Schistosoma japonicum in high endemic areas
Honggen CHEN ; Dandan LIN ; Yuesheng LI ; Yuemin LIU ; Donald P. Mcmanus ; Xinghua HUANG ; Zheng FENG ;
Chinese Journal of Schistosomiasis Control 1989;0(01):-
Objective To observe the effect of artemether in the control of prevalence and acute infection of Schistosoma japonicum in humans in high endemic areas. Methods During the transmission season (May-October), the residents in the pilot village took artemether with a 15- day interval to prevent the infection of S. japonicum. Results By the end of the transmission season, the egg positive rate was 0.83% and no acute case occurred in the artemether group, while 15.01% and 3 acute cases were observed in the placebo group. Conclusions Oral administration of artemether at a 15-day interval shows an effective protection from infection of S. japonicum, with a protection rate of 94.47% in residents of a high endemic area and it also shows marked effect to prevent acute schistosomiasis.
8.Effect of lamivudine treatment on interferon-γ and interleukin-4 serum levels in patients with chronic hepatitis B
Shuanghuan YAN ; Zhichen CAO ; Li KONG ; Yuemin NAN ; Qingshan ZHANG ; Huiru FENG ; Ying MA
Chinese Journal of Infectious Diseases 2009;27(1):27-30
Objective To investigate the effect of lamivudine (LAM) on serum interferon (IFN)-γ and interleukin (IL)-4 levels in patients with chronic hepatitis B(CHB). Methods Serum IFN-γ and IL-4 levels were measured with enzyme-linked immunosorbent assay (ELISA) in 66 CHB patients at baseline and 3, 6, 9 and 12 months after LAM treatment respectively. And 20 healthy volunteers served as healthy control. The comparision of pretreatment and post-treatment was done using t test and numberation data were analyzed by non parametric rank sum test. Results In HBeAg positive patients, the serum level of IFN-γ was (21.03±4.44) ng/L in complete response group, which was higher than partial response group [(13.85±3.92) ng/L] and non-response group [(10.63± 3.11) ng/L] (t=7.56,t=11.87, both P<0.01). Take that IFN-γ is 15.66 ng/L as boundry patients with high baseline IFN-γ level showed much higher complete response rate (31.0% vs 8.7%, x2 =8.391, P<0.01) and lower non-response rate (13.8% vs 52.2%,x2=4. 256, P<0.01) than those with low baseline IFN-γ levels. After LAM treatment, the IFN-γ/IL-4 ratios in complete response patients were approximate or even higher than those in healthy group, whereas the IFN-γ/ IL-4 ratios of patients with partial response and non response were lower than those in healthy group. In HBeAg negative patients, the IFN-γ/IL-4 ratios increased slowly but didn't reach the same levels of healthy group. Conclusions It is suggested that LAM treatment can increase IFN-γ release and reduce IL-4 release in CHB patients. The response type to LAM therapy is associated with the recovery of T helper cell (Th) 1/Th2 balance post-treatment and pretreatment IFN-γ levels.
9.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.
10.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.