Yi Dai

Sichuan University, Hua-yang, Sichuan, China

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Publications (8)12.58 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study aimed to investigate whether the cyclic stretch‑induced proliferation of human bladder smooth muscle cells (HBSMCs) is mediated by muscarinic (M) receptors, together with the signal transduction mechanisms involved in this process. HBSMCs seeded onto silicone membranes were subjected to different cyclic stretches (5, 10, 15 and 20%) for 6 and 12 h. As the effect of cyclic stretch on M2 and M3 mRNA expression levels was maximal at 6 h 10% stretch, all subsequent experiments were performed at this stretch. Western blot analysis was used to quantify M2, M3, protein kinase C (PKC) and phosphorylated (p)‑PKC protein expression levels, flow cytometry was employed to examine cell cycle distribution and a 5-bromo‑2-deoxyuridine (BrdU) incorporation assay was used to assess cell proliferation at this stretch. Subsequently, HBSMCs were exposed to different acetylcholine concentrations and/or cyclic stretch, M receptor antagonists [AF-DX16, an M2 receptor antagonist; 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP), an M3 receptor antagonist and atropine, a non‑selective antagonist] and GF 109203X, a PKC antagonist, to assess the possible underlying signaling mechanisms. Cyclic stretch was found to increase the proliferation of HBSMCs and the expression levels of M2, M3, PKC and p‑PKC proteins. M receptor and PKC antagonists exerted no apparent effect on nonstretched cells, but reduced the incorporation of BrdU into stretched cells; the most pronounced effects were observed when non‑selective M receptor and PKC antagonists were applied. Notably, 4‑DAMP did not inhibit stretch‑induced PKC activation. These results indicate that the activation of the M3 receptor signaling pathway in stretch‑induced HBSMC proliferation occurs via PKC-independent mechanisms.
    No preview · Article · Nov 2014 · Molecular Medicine Reports
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    ABSTRACT: Several midurethral sling (MUS) procedures, such as tension-free vaginal tape (TVT), TVT obturator (TVT-O), tension-free vaginal tape SECUR (TVT-S), and pubovaginal sling (PVS), have been used for the treatment of female stress urinary incontinence (SUI); however, which method is best for a particular patient group is not known. This study aimed to identify the best rationale for choosing the optimal MUS procedure for each patient. In total, 453 consecutive female patients with SUI who were treated with MUSs in West China Hospital of Sichuan University from September 2003 to September 2011 were enrolled in this study. All the patients underwent comprehensive pre-, intra-, and postoperative evaluations, including collection of demographic information, pelvic examination, and urodynamic testing, and operation-related complications were recorded. The Incontinence Quality of Life questionnaire was also completed. Under local or general anesthesia, 105 cases were treated with TVT, 243 with TVT-O, 90 with TVT-S, and 15 with PVS. Patients with different profiles in terms of age, symptom duration, concomitant procedures, urodynamic parameters, and pelvic organ prolapse (POP) quantification score were treated successfully; the body mass index did not differ significantly among the various treatment options. The cure and improvement rates were similar among the treatment groups: 97.14% (102/105) in TVT, 100% (243/243) in TVT-O, 98.89% (89/90) in TVT-S, and 100% (15/15) in PVS. Only minor complications were experienced by the patients. In conclusion, each MUS procedure was observed to be safe and effective in different subpopulations of patients, and the results suggest that appropriate patient selection is crucial for the success of each MUS procedure.
    No preview · Article · Mar 2014 · The Kaohsiung journal of medical sciences
  • Tong-Xin Yang · Yi Dai · Hong Shen
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    ABSTRACT: We present three cases of transvaginal removal of mesh exposure involving the bladder, including patient follow-up. Mesh exposure occurred secondary to placement of transvaginal mesh for management of pelvic organ prolapse. A pure transvaginal technique was performed to remove mesh exposure involving the bladder. Patient follow-ups were carefully recorded. All operative steps were completed transvaginally. The duration of follow-up for the three cases was 6, 11, and 19 months. One patient experienced recurrence of mesh exposure during follow-up. The other two patients were symptom-free after surgery. There were no major postoperative complications and no recurrence of cystocele. Transvaginal removal of mesh exposure involving the bladder is feasible. The pure transvaginal approach is applicable to various conditions with good outcomes, yet it cannot guarantee that exposure of residual fibers within the bladder will not recur.
    No preview · Article · Oct 2013 · International Urogynecology Journal
  • Yi Dai · Hong Shen · Yong Zhong Li
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    ABSTRACT: Introduction and hypothesis: This study investigated the value of transvaginal contrast-enhanced sonourethrography for the diagnosis of female urethral diverticulum (UD) by comparing results of contrast-enhanced ultrasound images and surgical findings. Methods: A total of 14 female UD patients underwent preoperative transvaginal contrast-enhanced sonourethrography between July 2010 and June 2012. History and physical examination were initially assessed by the same urologist. Transvaginal contrast-enhanced ultrasound imaging was performed and interpreted by the same ultrasonographer. Definite diagnosis was made by tracking the flow of the microbubbles into the cyst. Additionally, sagittal, cross-sectional, and dynamic images were obtained, and color Doppler ultrasound was applied in all cases. Data on the size, location, configuration, and opening of the UD was documented, and then compared with the surgical findings. Results: The most common symptoms presenting in the UD patients included urinary incontinence (71.5 %), recurrent urinary tract infection (57.1 %), frequency (50 %), urgency (35.7 %), dysuria (35.7 %), and dyspareunia (21.4 %). On physical examination, 8 out of 14 patients (57.1 %) had a palpable anterior vaginal wall mass, while 6 out of 14 patients (42.9 %) had no palpable mass. Transvaginal contrast-enhanced sonourethrography revealed 17 diverticula orifices in total and correlated well with surgical findings regarding the size, location, configuration, and the opening of the UD. Conclusions: In patients with chronic irritative bladder symptoms, but with no response to conventional treatment a high index of suspicion for UD should be maintained. Our study demonstrates that transvaginal contrast-enhanced sonourethrography is a useful tool for defining the size, location, configuration, and opening of the UD before surgery.
    No preview · Article · Sep 2013 · Journal of Clinical Ultrasound
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    ABSTRACT: Objective: To determine protein kinase C (PKC), c-Jun NH2-Terminal Kinase (JNK) and P38 mitogen-activated protein kinases (p38MAPK) expression levels and effects of their respective inhibitors on proliferation of human bladder smooth muscle cells (HBSMCs) when physiologically stretched in vitro. Materials and methods: HBSMCs were grown on silicone membrane and stretch was applied under varying conditions; (equibiaxial elongation: 2.5%, 5%, 10%, 15%, 20%, 25%), (frequency: 0.05, 0.1, 0.2, 0.5, 1Hz). Optimal physiological stretch was established by assessing proliferation with 5-Bromo-2-deoxyuridine (BrdU) assay and flow cytometry. PKC, JNK and p38 expression levels were analyzed by Western blot. Specificity was maintained by employing specific inhibitors; (GF109203X for PKC, SP600125 for JNK and SB203580 for p38MAPK), in some experiments. Results: Optimum proliferation was observed at 5% equibiaxial stretch (BrdU: 0.837±0.026 (control) to 1.462±0.023)%, (P<0.05) and apoptotic cell death rate decreased from 16.4±0.21% (control) to 4.5±0.13% (P<0.05) applied at 0.1Hz. Expression of PKC was upregulated with slight increase in JNK and no change in p38MAPK after application of stretch. Inhibition had effects on proliferation (1.075±0.024, P<0.05 GF109203X); (1.418±0.021, P>0.05 SP600125) and (1.461±0.01, P>0.05 SB203580). These findings show that mechanical stretch can promote magnitude-dependent proliferative modulation through PKC and possibly JNK but not via p38MAPK in hBSMCs.
    No preview · Article · Aug 2013 · Biochemical and Biophysical Research Communications
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    ABSTRACT: This study's aim is provide an overview of the patients who suffered spinal cord injury (SCI) after the magnitude 8.0 Wenchuan earthquake, including each patient's demographic and epidemiological characteristics, bladder management status, and quality of life (QOL). We also assessed the relationships between bladder management methods, symptomatic urinary tract infection (SUTI), and QOL. Two years after the 2008 Wenchuan earthquake, a cross-sectional face-to-face survey was conducted on 180 patients with SCI. A self-administered questionnaire and the WHOQOL-BREF assessment were used to assess injury-related information, bladder management methods, and SUTI. Statistical analysis was performed using the Chi-square test and analysis of variance. A p value <0.05 was considered statistically significant. This study found that a male-to-female ratio of approximately 1.2:1, including 98 (54.4%) male patients and 82 (45.6%) female patients. Thoracic-level injuries were seen in 82 patients (45.56%), 60 (33.33%) patients had lumbar-level injuries, 18 (8.33%) patients had thoracolumbar-level injuries, and a small number of patients had cervical- or sacral-level injuries. Sixty-two patients (34.44%) demonstrated normal voiding, 65 (36.11%) required manually assisted voiding, 29 (16.11%) required catheterization, and 24 (13.33%) used aurine-collecting apparatus. The prevalence of SUTI was 43.89%. Patients who emptied their bladder via manually assisted voiding, catheterization, or with the use of a urine-collecting apparatus demonstrated higher rates of SUTI compared with patients who voided normally (p < 0.05); the patients who required catheterization had higher rates of SUTI compared with patients who required manually assisted voiding (p < 0.05). When manually assisted voiding and catheterization were compared with the use a urine-collecting apparatus, no statistically significant differences were observed in terms of the risk of developing SUTI. The patients in this study demonstrated low scores on the WHOQOL-BREF physical domain (11.61 ± 3.80), psychological domain (10.11 ± 3.63), social domain (11.46 ± 2.84), and environmental domain (11.86 ± 2.51). The patients who reported normal voiding also demonstrated the best QOL in terms of physical, psychological, and social component scores (p < 0.05). In conclusion, the percentage of women in this study is higher than that reported in other studies on traumatic causes of SCI. Patients who suffered SCI following the Wenchuan earthquake demonstrate poor bladder management status and are unable to take advantage of urodynamic testing that is used to monitor the functional state of the bladder. This study's findings indicate that bladder management methods influence the rate of SUTI and the QOL of patients with SCI. Caring for SCI patients following a disaster requires comprehensive long-term planning. Bladder management of patients with SCI is essential for improving the QOL of these patients.
    No preview · Article · Nov 2012 · The Kaohsiung journal of medical sciences
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    ABSTRACT: This systematic review was performed to assess the necessity and complications of stenting before extracorporeal shock wave lithotripsy in the management of upper urinary stones. A systematic research of PubMed®, EMBASE® and the Cochrane Library was performed to identify all randomized controlled trials. The comparisons were about the outcomes and complications of extracorporeal shock wave lithotripsy in the management of upper urinary stones with or without Double-J stenting before extracorporeal shock wave lithotripsy, including stone-free rate, Steinstrasse, lower urinary tract symptoms, hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, and nausea and vomiting. We used the Cochrane Collaboration's Review Manager (RevMan) 5.0.2 software for statistical analysis. Eight randomized controlled trials were included in analysis that reported 876 patients in total, divided into the stented group of 453 and the stentless group of 423. All studies recorded the stone-free rate and the results of the meta-analysis showed no difference between the groups (RR 0.97, 95% CI 0.91-1.03, p = 0.27). The total incidence of Steinstrasse in the stented group was similar to that of the stentless group with the exception of 1 study. However, the incidence of lower urinary tract symptoms was significantly higher in the stented group than in the stentless group (RR 4.10, 95% CI 2.21-7.61, p <0.00001). Significant differences could not be found in hematuria, fever, urinary tract infection, pain and analgesia, auxiliary treatment, or nausea and vomiting between the groups. The systematic review suggested significant advantages of stenting before extracorporeal shock wave lithotripsy compared to in situ extracorporeal shock wave lithotripsy in terms of Steinstrasse. However, stenting did not benefit stone-free rate and auxiliary treatment after extracorporeal shock wave lithotripsy, and it induced more lower urinary tract symptoms. More high quality, randomized controlled trials are needed to address this issue.
    No preview · Article · Aug 2011 · The Journal of urology
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    ABSTRACT: Objective. Treatment of anterior vaginal wall prolapse and stress urinary incontinence (SUI) with transobturator tension-free vaginal mesh (anterior Prolift) and concomitant ten-sion-free vaginal tape-obturator (TVT-O) has been proved feasible, safe and effective. However, there is little known about the influ-ence of pregnancy on women who have had such procedures before pregnancy. Design and methods. A 32-year-old woman (gravid 1, para 1) with two years history of SUI and nine months history of pelvic organ pro-lapse (POP) was treated with transobturator tension-free vaginal mesh (anterior Prolift) and concomitant TVT-O. Her recovery was excellent, and she was pregnant eight months after the operation. Results. The patient went through her preg-nancy smoothly with no special discomfort and successfully delivered an infant via caesarean section without recurrence of POP and SUI. Her last visit to our clinic about 14 months after caesarean section revealed that the ante-rior Prolift mesh and TVT-O mesh still remained intact and the position of the vaginal fornix, anterior and posterior walls and uterus also remained normal. Conclusions. Pelvic floor reconstruction with vaginal mesh (Prolift) may have positive significance for young patients who desire uterine preservation for future pregnancies. However, further studies are warranted to determine whether it can be used in pregnant women or women planning future pregnan-cies.
    Preview · Article · Jul 2011