Yong Guan's research while affiliated with Tianjin University and other places

There is a great clinical need for regenerating urinary tissue. Native urethras and ureters have bidirectional aligned smooth muscle cells (SMCs) layers, which plays a pivotal role in micturition and transporting urine and inhibiting reflux. Thus far, urinary scaffolds have not been designed to induce the native‐mimicking aligned arrangement of SMCs. In this study, a tubular decellularized extracellular matrix (dECM) with an intact internal layer and bidirectional aligned microchannels in the tubular wall, which is realized by the subcutaneous implantation of a template, followed by the removal of the template, and decellularization, is engineered. The dense and intact internal layer effectively increases the leakage pressure of the tubular dECM scaffolds. Rat‐derived dECM scaffolds with three different sizes of microchannels are fabricated by tailoring the fiber diameter of the templates. The rat‐derived dECM scaffolds exhibiting microchannels of ≈65 µm show suitable mechanical properties, good ability to induce the bidirectional alignment and growth of human bladder SMCs, and elevated higher functional protein expression in vitro. These data indicate that rat‐derived tubular dECM scaffolds manifesting double‐layer aligned microchannels may be promising candidates to induce the native‐mimicking regeneration of SMCs in urethra and ureter reconstruction.

Introduction Bracka repair and staged transverse preputial island flap urethroplasty are both significant methods in treating proximal hypospadias. They utilize the flap and graft techniques, respectively, to achieve a satisfactory success rate. This study aimed to compare the outcomes of these 2 methods in the treatment of proximal hypospadias with severe ventral curvature. Methods We retrospectively analyzed 117 cases of proximal hypospadias with severe ventral curvature who had undergone either Bracka repair ( n = 62) or staged transverse preputial island flap urethroplasty ( n = 55). All operations were performed by a single surgeon, and the choice of method was determined by the surgeon's preference based on his experience. Cosmetic outcome was evaluated with Pediatric Penile Perception Score (PPPS). Patients' characteristics including age, penis length, glans diameter, length of the urethral defect and ventral curvature degree, cosmetic outcomes, and complication rates were all compared. Results There was no significant difference in age, penis length, glans diameter, length of the urethral defect, or ventral curvature degree. In the Bracka group, there were 5 patients with fistula, 1 patient with stricture, and 1 case of dehiscence. In the staged transverse preputial island flap urethroplasty group, there were 4 patients with fistula, 1 with stricture, and 2 with diverticulum. The scores of shaft skin and general appearance were consistently higher in the Bracka group than in the staged transverse preputial island flap urethroplasty group. The differences in complication rate and cosmetic outcome were not statistically different ( P > 0.05). Conclusions Bracka repair and staged transverse preputial island flap urethroplasty are both satisfactory staged surgical options for proximal hypospadias with severe ventral curvature and have similar complication rates. Bracka repair may create a better appearance, but more studies are needed to confirm this finding. Pediatric surgeons should consider additional factors, such as the patient's specific condition, parents' inclination, and personal experience, rather than safety, to make the best choice between the 2 methods.

Background: Surgical correction of proximal hypospadias is challenging. The complication rate of proximal hypospadias is still high, and the debate over its optimal treatment is ongoing. Duckett's method is a classic non-staging operation, and two-stage Bracka repair is an attractive alternative procedure. Herein, we retrospectively analyzed the effects of two surgical techniques on proximal hypospadias in order to reduce the complication rates of proximal hypospadias, and analyzed the various risk factors that cause complications. Methods: This study retrospectively evaluated 94 consecutive patients who underwent repair of penoscrotal or proximal defects between 2015 and 2019. Patients were assigned to two groups: 46 patients were treated with Bracka and 48 with Duckett. Patient age at surgery, urethral meatus location, and postoperative complications were recorded. One-way analysis of variance (ANOVA) was used to analyze the length and curvature of the penis and the length of the urethral defect. Results: There was no significant difference between the two groups in terms of age and type of hypospadias. In the Bracka group, there was 1 case (2.2%) of meatal stenosis after the first stage, which was restored with ureteral dilatation. After second-stage repair, a urethral fistula was noted in 4 cases (8.7%) and strictures in 2 cases (4.3%). In the Duckett group, urethral fistulas were noted in 8 cases (16.7%), strictures in 4 cases (8.3%), partial glans dehiscence in 4 cases (8.3%), and diverticulum in 1 case (2.1%) postoperatively. Compared with the Duckett group, the overall complication rate for Bracka repair was lower (35.4% vs. 13%, P=0.016). In addition, compared with the Duckett group, children with perineal hypospadias who were treated with the Bracka operation had fewer postoperative complications (100% vs. 13%, P=0.015). Risk factor analysis showed that the initial curvature of the penis, initial urethral defect, and degree of penile curvature after skin degloving were not correlated with complications. There was a significant correlation between urethral defects after correction of the chordee and urethral fistulas (P=0.019). Conclusions: Compared with the Duckett procedure, the Bracka two-stage repair may be a safer and more reliable approach for proximal hypospadias in children. The Bracka two-stage repair should be used for perineal hypospadias. The larger the urethral defect after chordee correction, the greater the possibility of a postoperative urethral fistula.

Multifunctional phototheranostics that integrate several diagnostic and therapeutic strategies into one platform hold great promise for precision medicine. However, it is really difficult for one molecule to possess multimodality optical imaging and therapy properties that all functions are in the optimized mode because the absorbed photoenergy is fixed. Herein, a smart one‐for‐all nanoagent that the photophysical energy transformation processes can be facilely tuned by external light stimuli is developed for precise multifunctional image‐guided therapy. A dithienylethene‐based molecule is designed and synthesized because it has two light‐switchable forms. In the ring‐closed form, most of the absorbed energy dissipates via nonradiative thermal deactivation for photoacoustic (PA) imaging. In the ring‐open form, the molecule possesses obvious aggregation‐induced emission features with excellent fluorescence and photodynamic therapy properties. In vivo experiments demonstrate that preoperative PA and fluorescence imaging help to delineate tumors in a high‐contrast manner, and intraoperative fluorescence imaging is able to sensitively detect tiny residual tumors. Furthermore, the nanoagent can induce immunogenic cell death to elicit antitumor immunity and significantly suppress solid tumors. This work develops a smart one‐for‐all agent that the photophysical energy transformation and related phototheranostic properties can be optimized by light‐driven structure switch, which is promising for multifunctional biomedical applications.

Objective To explore a novel repair method for proximal hypospadias with incomplete penoscrotal transposition in children and evaluate its safety and outcomes. Methods A retrospective analysis of clinical data was conducted for 86 children with severe proximal hypospadias with incomplete penoscrotal transposition who were hospitalized in our department between June 2018 and February 2021. In total, 42 patients (Group A) underwent repair following a one-stage method in which tunica vaginalis flap-covering was combined with a modified Glenn–Anderson procedure, while 44 patients (Group B) underwent a two-step repair consisting of tunica vaginalis flap-covering using the Duplay technique and the modified Glenn–Anderson procedure. The two groups were compared on operation time, length of postoperative hospital stay, postoperative complications, and associated costs. Results All operations were successful in both groups. No statistical difference was observed between the two groups in incidence of stenosis of the urinary meatus (2.38% vs. 4.54%, P = 0.279), urethral stricture (2.38% vs. 2.27%, P = 0.948), urinary fistula (7.14% vs. 6.82%, P = 0.907), or urinary infection (7.14% vs. 4.55%, P = 0.309). Additionally, there was no statistical difference between the groups in operation time (63.21 ± 5.20 vs. 62.07 ± 4.47 min, P = 0.059), postoperative off-bed time (7.02 ± 1.32 vs. 6.84 ± 1.20 days, P = 0.456), or duration of hospitalization (10.55 ± 1.15 vs. 10.15 ± 1.45 days, P = 0.092). However, Group B patients underwent an additional second-stage operation, incurring extra costs. Three months after surgery, Group A were judged more positively on the PPPS (specifically receiving higher scores on shaft skin and general appearance) by both the parents (shaft skin: 2.10 ± 0.82 vs. 1.93 ± 0.62, P = 0.024; general appearance: 2.16 ± 0.91 vs. 1.93 ± 0.72, P = 0.042) and the surgeon (shaft skin: 2.42 ± 0.70 vs. 2.25 ± 0.58, P = 0.025; general appearance: 2.38 ± 0.69 vs. 2.29 ± 0.51, P = 0.041). In most cases, the parents and surgeon were satisfied with the appearance of the genitals after one-stage repair. Conclusion The advantages of the novel repair technique include use of a single-stage operation, producing a better appearance at a lower cost. The tunica vaginalis flap-covering method is not only demonstrated to be safe and effective, but it is also a simpler method than the conventional operation.

Objective: To evaluate safety and efficacy of a novel method of bilateral patent processus vaginalis ligation in transumbilical single-site multiport laparoscopic orchiopexy for children. Methods: A retrospective study was carried out comparing the novel ligation and conventional ligation performed by a single surgeon between July, 2017-July, 2018. The patients were divided into the novel group (42 cases) and the conventional group (59 cases). In the novel group, transumbilical single-site multiport laparoscopic orchiopexy was performed and the bilateral internal rings was stitched with “8” pattern suture. In the conventional group, the conventional TriPort laparoscopic orchiopexy was performed and purse string suture was used to fix the internal rings. The parameters of operative duration time, postoperative hospital stay; postoperative complications were compared between 2 groups. Results: All operations were successful. No Perioperative period complications were found and all patients were discharged within 4-6 days after operation. There is no statistic difference in the surgery time and hospitalization day. However, there is significant difference in the Pain face scale scores after day 2(1.60±0.73 VS 2.02±0.86). And there is no scar and the satisfactory cosmetic could be seen in scrotum and inguinal area in the novel group. Conclusion: The novel ligation was safety and efficacy. It is relatively easy to perform with smaller scar and less pain. We propose the novel ligation as a more viable treatment option for pediatric cryptorchidism with bilateral patent processus vaginalis.

Background: Left paraduodenal hernia (PDH) is a mesenterico-parietal hernia with retroperitoneal retrocolic herniation of the small bowel into a sac formed by a peritoneal fold located near the fourth portion of the duodenum. It’s a rare cause of hydronephrosis by compressed the upper left ureter. Traditionally, PDH are treated by laparotomy. Case presentation: An 8-year-old boy’s primary purpose was the treatment of cryptorchidism. But hydronephrosis was detected and it was induced by left paraduodenal hernia. Diagnostic laparoscopic exploration confirmed the diagnosis left paraduodenal hernia secondary hydronephrosis. Cryptorchidism was the primary purpose of treatment. The patient was treated with laparoscopic surgery, fixed left paraduodenal hernia, released the ureteropelvic junction obstruction (UPJO) and treated hydronephrosis. Conclusion: Secondary surgery for treating cryptorchidism would be performed and the long-term follow up was necessary.This case suggests us a rare cause of hydronephrosis in children. Every why has a wherefore. We must pay much attention to any unusual details in our medical work even though these details aren’t related to our primary objects.

Rationale Left paraduodenal hernia (PDH) is a mesenterico-parietal hernia with retroperitoneal retrocolic herniation of the small bowel into a sac formed by a peritoneal fold located near the fourth portion of the duodenum. It’s a rare cause of hydronephrosis by compressed the upper left ureter. Traditionally, PDH are treated by laparotomy. Patient concerns An 8-year-old boy’s primary purpose was the treatment of cryptorchidism. But hydronephrosis was detected and it was induced by left paraduodenal hernia. Diagnosis Diagnostic laparoscopic exploration confirmed the diagnosis left paraduodenal hernia secondary hydronephrosis. Cryptorchidism was the primary purpose of treatment. Interventions The patient was treated with laparoscopic surgery, fixed left paraduodenal hernia, released the ureteropelvic junction obstruction (UPJO) and treated hydronephrosis. Out comes Secondary surgery for treating cryptorchidism would be performed and the long-term follow up was necessary. Lessons This case suggests us a rare cause of hydronephrosis in children. Every why has a wherefore. We must pay much attention to any unusual details in our medical work even though these details aren’t related to our primary objects.

The only effective clinical treatment for many end-stage lung diseases is lung transplantation. However, chronic rejection of transplanted lung affects the long-term efficacy of lung transplantation to a large extent, thereby limiting the clinical application of lung transplantation. Occlusive bronchiolitis (OB) is a major cause of chronic functional loss of the transplanted lung. However, the OB pathogenesis remains unclear. Therefore, studying the OB pathogenesis and finding effective intervention methods are highly important. This study analyzed changes in the expression profile of microRNAs and transcription factors in mice with OB after orthotopic tracheal transplantation. miR-27a-3p was upregulated in lung tissue 20 days after transplantation. Transcription factor microarray analysis revealed that Smad3 was significantly downregulated. A miRNA–mRNA interaction network was constructed, and specific regulatory effects of miR-27a-3p on Smad3 were found. Smad3 was strongly associated with tumorigenesis and organ fibrosis. Compared with the control group, miR-27a-3p inhibited the epithelial–mesenchymal transformation (EMT) of lung epithelial cells. In addition, miR-27a-3p inhibition promoted the invasion and migration of lung epithelial cells. Dual luciferase reporter gene assay showed that miR-27a-3p can regulate the promoter activity of Smad3. MiR-27a-3p also inhibited the expression of inflammatory cytokines. Western blot results showed that miR-27a-3p can upregulate the E-cadherin expression and downregulate the expression of vimentin, fibronectin, and α-SMA. By studying the OB pathogenesis, we found that inhibition or alteration of the occurrence of EMT may reduce the proportion of chronic rejection of lung transplantation. MiR-27a-3p may also be developed as a new drug for the OB therapy. This finding will provide many possibilities for OB treatment and improve the prognosis of patients with OB.

In this study, a three layered poly (ε-caprolactone) (PCL) graft (tPCL) was fabricated by electrospinning PCL and electrospraying poly (ethylene oxide) (PEO), which has a thin dense inner layer, a loose middle layer, and a dense outer layer. Regular PCL grafts (rPCL) with only a dense layer were used as control. In vivo evaluation was performed in rabbit carotid artery. Enhanced cell infiltration, rapid regeneration of endothelium and smooth muscle layers, and increased elastin deposition were observed within the tPCL graft wall. After 3 months, tPCL grafts showed faster PCL degradation than the rPCL grafts. Infiltrated macrophages in the tPCL grafts secreted higher level of monocyte chemoattractant protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) which enhanced vascular regeneration. In conclusion, the tPCL graft may be a useful vascular prosthesis and worth for further investigation.