scholarly journals Cell-Seeded Acellular Artery for Reconstruction of Long Urethral Defects in a Canine Model

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hao Zhong ◽  
Yamei Shen ◽  
Danhui Zhao ◽  
Guoqiang Yan ◽  
Chengai Wu ◽  
...  

The management of urethral stricture remains a major therapeutic challenge in clinics. Herein, we explored the feasibility of reconstructing a relatively long segment of the urethra by the cell-seeded acellular artery in a canine model. The acellular arterial matrix was obtained from the excised carotid artery of donor dogs. Autologous adipose-derived stem cells (ADSCs) from 6 male dogs were grown and seeded onto the premade acellular arterial matrix. A 3 cm long segment of the urethra was resected in 12 male dogs. Urethroplasty was performed with the acellular arterial matrix seeded with ADSCs in 6 animals and without cells in 6. Serial urethrography was performed at 1 and 3 months postoperatively. Wide urethral calibers without any signs of strictures were confirmed in all 6 animals in the experimental group. In contrast, urethral stricture was demonstrated in 3 animals in the control group. The graft was highly epithelialized and smooth in the experimental group, while graft contracture and scar formation were showed in the control group. Histologic analysis of the cell-seeded arterial matrix at 1 month confirmed the presence of multilayered urothelium and muscle. The levels of tissue formation developed over time with a progressive increase in muscle content. In contrast, extensive fibrosis and sparse smooth muscle were seen in animals treated with matrix without ADSCs. This study provides preclinical evidence that the ADSC-seeded arterial matrix can be used as a tubularized scaffold in the reconstruction of 3 cm long urethral defect in a male canine model. The ADSC-seeded arterial matrix remodels and regenerates normal-appearing urethral tissue layers over time.

2020 ◽  
Author(s):  
Dan Li ◽  
Zhou Shen ◽  
Yujie Xu

Abstract Background: The repair of anterior urethral stricture and hypospadias require urethral reconstruction. We conduct the study to investigate the efficacy of anterior urethral reconstruction using everted saphenous vein graft in tubular fashion. Methods: Twelve male beagles were randomly divided into three groups: experimental group( n=5), control group( n=5) and normal group( n=2). A 3 cm defect in anterior urethra was created. Autologous saphenous vein graft was harvested. In experimental group, urethral defect was replaced by everted saphenous vein graft in tubular fashion. In control group, urethral reconstruction was performed using uneverted saphenous vein graft. At 6 months postoperatively, beagles in all groups received retrograde urethrography to evaluate urethral patency and were killed for histological examination. Results: Retrograde urethrography showed the urethral caliber of beagles in experimental group were similar to those of normal. Ether urethral stricture or fistula were detected in all animals in control group. In experimental group, the everted saphenous vein graft completely integrated into the urethra. The reconstructed urethra had a wide lumen and was completely covered by urothelium. The subepithelial collagen and muscle fibers were well formed and highly organized. Everted saphenous vein graft had a high ability of neovascularization. In control group, the reconstructed segment had a fibrotic urethral lumen in which urothelium was not intact. And there were few newly formed capillaries. Conclusions: Everted saphenous vein graft can be used as tubular substitute material for anterior urethral strictures and hypospadias.


BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dan Li ◽  
Zhou Shen ◽  
Yujie Xu

Abstract Background A long segment stricture in the anterior urethra is a challenge in urology. We conducted a study to investigate the efficacy of anterior urethral reconstruction using an everted saphenous vein graft (SVG) in a tubular fashion. Methods Twelve male beagles were randomly divided into three groups: experimental group (n = 5), control group (n = 5) and normal group (n = 2). A 3 cm defect in the anterior urethra was created. Autologous SVG was harvested. In the experimental group, urethral defect was replaced by an everted SVG in a tubular fashion. In the control group, urethral reconstruction was performed using an uneverted SVG. Beagles in all groups received retrograde urethrography to evaluate urethral patency and were killed for histological examination 6 months after operation. Results Four beagles in the experimental group had no voiding difficulty and the other one could not void spontaneously. Retrograde urethrography showed the four beagles in experimental group had wide urethral lumens. Ether urethral stricture or fistula were detected in all animals in the control group. Histological analysis of the four beagles in the experimental group indicated the everted SVG completely integrated into the urethra. The reconstructed urethra contained a wide lumen and was completely covered by urothelium. The periurethral collagen and muscle fibers formed and were highly organized. Everted SVG showed a high ability of neovascularization. In the control group, the reconstructed segment showed a fibrotic urethral lumen where the urothelium was not intact. Only few new capillaries were formed. Conclusions Everted SVG demonstrates for a promising strategy for potential urethral stricture repair.


2021 ◽  
Vol 9 (6) ◽  
pp. 1163
Author(s):  
Eduarda Alexandra Gonçalves de Oliveira Moura ◽  
Daniela Gomes da Silva ◽  
Caio Henrique Turco ◽  
Thainara Vitoria Carnevalli Sanches ◽  
Gabriel Yuri Storino ◽  
...  

Since the occurrence of swine salmonellosis has increased over time and control strategies other than biosecurity are highly recommended, the present study aimed to evaluate the efficacy of vaccination with Salmonella Choleraesuis and Salmonella Typhimurium bacterins in pigs. Two experimental groups were formed: G1, animals immunized with two doses of a commercial vaccine (n = 20); G2, control group (n = 20). After vaccination, all pigs were orally challenged (D0) with 108 CFU of Salmonella Typhimurium and evaluated for 40 days. Every 10 days after D0, five piglets from each experimental group were euthanized and submitted to the necroscopic examination, when organ samples were collected. Blood samples and rectal swabs were collected before the first dose of the vaccine (D−42), before the second dose (D−21), before the challenge (D0), and thereafter, every three days until D39. Blood count, serum IgG measurement by ELISA, and the excretion of Salmonella Typhimurium in feces were evaluated. While the results from blood count and serum IgG concentration did not differ, the detection and excretion of Salmonella between G1 and G2 differed (p < 0.05). Therefore, it was observed that this vaccine partially protected the animals against experimental infection with Salmonella Typhimurium, reducing the excretion of bacteria in feces.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Man Amanat ◽  
Anahita Majmaa ◽  
Morteza Zarrabi ◽  
Masoumeh Nouri ◽  
Masood Ghahvechi Akbari ◽  
...  

Abstract Background This study assessed the safety and efficacy of intrathecal injection of umbilical cord tissue mesenchymal stem cells (UCT-MSC) in individuals with cerebral palsy (CP). The diffusion tensor imaging (DTI) was performed to evaluate the alterations in white-matter integrity. Methods Participants (4–14 years old) with spastic CP were assigned in 1:1 ratio to receive either UCT-MSC or sham procedure. Single-dose (2 × 107) cells were administered in the experimental group. Small needle pricks to the lower back were performed in the sham-control arm. All individuals were sedated to prevent awareness. The primary endpoints were the mean changes in gross motor function measure (GMFM)-66 from baseline to 12 months after procedures. The mean changes in the modified Ashworth scale (MAS), pediatric evaluation of disability inventory (PEDI), and CP quality of life (CP-QoL) were also assessed. Secondary endpoints were the mean changes in fractional anisotropy (FA) and mean diffusivity (MD) of corticospinal tract (CST) and posterior thalamic radiation (PTR). Results There were 36 participants in each group. The mean GMFM-66 scores after 12 months of intervention were significantly higher in the UCT-MSC group compared to baseline (10.65; 95%CI 5.39, 15.91) and control (β 8.07; 95%CI 1.62, 14.52; Cohen’s d 0.92). The increase was also seen in total PEDI scores (vs baseline 8.53; 95%CI 4.98, 12.08; vs control: β 6.87; 95%CI 1.52, 12.21; Cohen’s d 0.70). The mean change in MAS scores after 12 months of cell injection reduced compared to baseline (−1.0; 95%CI −1.31, −0.69) and control (β −0.72; 95%CI −1.18, −0.26; Cohen’s d 0.76). Regarding CP-QoL, mean changes in domains including friends and family, participation in activities, and communication were higher than the control group with a large effect size. The DTI analysis in the experimental group showed that mean FA increased (CST 0.032; 95%CI 0.02, 0.03. PTR 0.024; 95%CI 0.020, 0.028) and MD decreased (CST −0.035 × 10-3; 95%CI −0.04 × 10-3, −0.02 × 10-3. PTR −0.045 × 10-3; 95%CI −0.05 × 10-3, −0.03 × 10-3); compared to baseline. The mean changes were significantly higher than the control group. Conclusions The UCT-MSC transplantation was safe and may improve the clinical and imaging outcomes. Trial registration The study was registered with ClinicalTrials.gov (NCT03795974).


2020 ◽  
Vol 17 (1) ◽  
pp. 54
Author(s):  
Nazem Ghasemi ◽  
Arefeh Basiri ◽  
Batool Hashemibeni ◽  
Mohammad Kazemi ◽  
Ali Valiani ◽  
...  

Author(s):  
Nikolai MALYUK ◽  
◽  
Yuliia DEMIANTSEVA ◽  
Yuriy KHARKEVYCH ◽  
Roman BOKOTKO ◽  
...  

The purpose of the study was to investigate the regenerative processes in the knee joint of rabbits with experimental osteoarthritis after using of allogeneic bone marrow stem cells and a traditional treatment with the non-steroidal anti-inflammatory drug Meloxicam. For the experiment were used 27 male California rabbits (males). Three groups of animals were formed: a control group; the first experimental group treated by the traditional method; the second experimental group treated with allogeneic mesenchymal stem cells (MSC). Animals in the three groups were subjected to osteoarthritis of the knee joint by double injection of 3.44% retinol acetate into the joint cavity at a dose of 1 ml at intervals of 7 days. Tissue from the affected site was sampled for histological examination at 7, 14 and 28 days. The histological sections were stained with haematoxylin-eosin and examined under a microscope. It has been established that intra-articular administration of 3.5 × 106 cells of allogeneic MSCs in experimental osteoarthritis contributes to the restoration of the superficial layer of cartilage, as evidenced by the formation of columns of chondrocytes in the middle layer of articular cartilage and the appearance of isogenic groups of cartilage cells with basophilic cytoplasm in the matrix, uniform articular surface. The use of the traditional method of treating rabbits using the drug Meloxicam is accompanied by incomplete chondrogenesis: part of the chondrocytes is localized in typical chambers, in some cases chondrocyte chambers did not differentiate; articular cartilage had unequal thickness, cell placement was uneven.


2020 ◽  
Author(s):  
Poh-Ching Tan ◽  
Pei-Chuan Chao ◽  
Chen Cheng ◽  
Chu-Hsin Chen ◽  
Ru-Lin Huang ◽  
...  

Abstract Background: The regeneration response of skin to mechanical stretching in vivo has been explored in reconstructive surgery for repairing large-scale deformities. The ability of skin to regenerate limits the reconstructive outcome. Here, we propose an approach in which autologous adipose-derived stem cells and mechanical stretching are combined to overcome this limitation and promote skin regeneration.Methods: This randomized, blinded, placebo-controlled clinical trial screened 22 participants undergoing tissue expansion with a presence of exhausted regeneration. Twenty eligible participants received intradermal injections with stromal vascular fraction (SVF) or placebo treatments. Follow-ups were conducted at 4, 8, and 12-weeks to assess efficacy and for 2-years to assess safety. The primary endpoint was the expanded skin thickness at 12 weeks. The secondary endpoints included the skin thickness at 4 and 8 weeks, the expansion index (EI) and the skin texture score at all visits. Results: The skin thickness of the SVF group was significantly higher than that of the control group at both 8 weeks (mean difference 0.78 [95% CI -1.43 to -0.11]; p = 0.018) and 12 weeks(0.65 [95% CI -1.30 to -0.01]; p = 0.046). In the SVF group, the increment of skin thickness was significant at 4 weeks (0.49 [95% CI -0.80 to -0.06]; p = 0.010) to 8 weeks (0.45 [95% CI -0.92 to 0.02]; p = 0.026) and maintained after 12 weeks, whereas that in the control group was reduced after 8 weeks (0.42 [95% CI -0.07 to 0.91]; p = 0.037). The SVF group showed higher EI increments than the control group (0.50 [95% CI -0.00 to 0.99]; p = 0.047). The skin texture scores in the SVF group were higher than those in the control group at 12 weeks. Histologically, the SVF-treated expanded skin showed more proliferating cells and blood vessels, and the volume of extracellular matrix increased. No severe adverse events occurred.Conclusions: Transplantation of autologous adipose-derived stem cells can expedite the potency of mechanical stretch-induced skin regeneration and provide clinical reconstruction with plentiful tissue. Trial registration: This trial was registered with Chinese Clinical Trial, ChiCTR2000039317 (registered 23 Oct 2020 - retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=62738).


2021 ◽  
Author(s):  
Vincent De Boer ◽  
Howard Spoelstra

Social Annotation (SA) tools can be used to facilitate active and collaborative learning when students have to study academic texts. However, making these tools available does not ensure students participate in argumentative discussions. Scaffolding students by means of collaborations scripts geared towards collaboration and discussion encourages students to engage in meaningful, high-quality interactions. We conducted an experiment with students (n=59) in a course running at a Dutch university, using the SA tool Perusall. A control group received normal instructions, while an experimental group received scaffolding through collaboration scripts. The results showed a significant increase in the number of responses to fellow students for the experimental group compared to the control group. The quality of the annotations, measured on levels of Bloom’s taxonomy, increased significantly for the experimental group compared to both its baseline measurement and the control group. However, when scaffolding was faded out over subsequent assignments these differences became non-significant. The experimental groups’ increased quality of annotations did not remain over time, suggesting that internalization of the scripts was not achieved.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Masaaki Ii ◽  
Ayumi Yokoyama ◽  
Miki Horii ◽  
Hiroshi Akimaru ◽  
Takayuki Asahara

Background: Recently, human multipotent adipose-derived stem cells (hMADSs) have been isolated featuring extensive expansion capacity ex vivo. However, little is known about the therapeutic efficacy of hMADS in ischemic heart diseases. We tested the hypothesis that hMADS transplantation may contribute to cardiac functional recovery following myocardial infarction (MI). Methods and Results: Nude rats were either transplanted with hMADSs (5x10 5 /rat, n=10) or PBS (control, n=9) in ischemic myocardium immediately following MI induction. The cardiac function, infarct size and capillary density in the peri-infarct area were evaluated by echocardiography and immunostaining 28 days after surgery. The cardiac function was significantly greater with increased capillary density and reduced fibrosis area in the hMADS group than that in the control group. Next, we examined tissue regeneration in the infarct heart by the transplanted hMADSs. However, remarkable differentiation of hMADSs into any cardiac cell lineages was not detected. To explore another mechanism for the favorable effect of hMADSs, we further examined mRNA expression of cytokines in hMADSs under hypoxic conditions. Although hypoxia decreased the expressions, robust VEGF, bFGF, and SDF-1α expressions were detected in hMADSs. Notably, the stem/progenitor chemokine SDF-1α expression in hMADSs was significantly greater than that in human mesenchymal stem cells that are well known to have a therapeutic effect on ischemic heart diseases. We then focused on SDF-1α /CXCR4 axis and examined the contribution of bone marrow (BM)-derived endothelial progenitor cells (EPCs), that have CXCR4 receptor for SDF-1v, to ischemic myocardium using a Tie2/LacZ BM transplantation nude mouse model. β-gal positive EPCs are frequently observed in ischemic myocardium in the hMADS group compared to the control group. Conclusion: hMADSs exhibit a therapeutic effect on cardiac function following MI with the production of VEGF, bFGF, and SDF-1α demonstrating paracrine effects rather than direct contribution to cardiac regeneration. These findings suggest that transplanted hMADSs and recruited EPCs may synergistically promote angiogenesis playing a role in ischemic myocardium.


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