Xuliang Li

Ultrasound microbubble-mediated delivery of the siRNAs targeting MDR1 reduces drug resistance of yolk sac carcinoma L2 cells

BackgroundMDR1 gene encoding P-glycoprotein is an ATP-dependent drug efflux transporter and related to drug resistance of yolk sac carcinoma. Ultrasound microbubble-mediated delivery has been used as a novel and effective gene delivery method. We hypothesize that small interfering RNA (siRNA) targeting MDR1 gene (siMDR1) delivery with microbubble and ultrasound can down-regulate MDR1 expression and improve responsiveness to chemotherapeutic drugs for yolk sac carcinoma in vitro.MethodsRetroviral knockdown vector pSEB-siMDR1s containing specific siRNA sites targeting rat MDR1 coding region were constructed and sequence verified. The resultant pSEB-siMDR1 plasmids DNA were encapsulated with lipid microbubble and the DNA release were triggered by ultrasound when added to culture cells. GFP positive cells were counted by flow cytometry to determine transfection efficiency. Quantitative real-time PCR and western blot were performed to determine the mRNA and protein expression of MDR1. P-glycoprotein function and drug sensitivity were analyzed by Daunorubicin accumulation and MTT assays.ResultsTransfection efficiency of pSEB-siMDR1 DNA was significantly increased by ultrasound microbubble-mediated delivery in rat yolk sac carcinoma L2 (L2-RYC) cells. Ultrasound microbubble-mediated siMDR1s delivery effectively inhibited MDR1 expression at both mRNA and protein levels and decreased P-glycoprotein function. Silencing MDR1 led to decreased cell viability and IC50 of Vincristine and Dactinomycin.ConclusionsOur results demonstrated that ultrasound microbubble-mediated delivery of MDR1 siRNA was safe and effective in L2-RYC cells. MDR1 silencing led to decreased P-glycoprotein activity and drug resistance of L2-RYC cells, which may be explored as a novel approach of combined gene and chemotherapy for yolk sac carcinoma.

Potential spermatogenesis recovery with bone marrow mesenchymal stem cells in an azoospermic rat model.

Non-obstructive azoospermia is the most challenging type of male infertility. Stem cell based therapy provides the potential to enhance the recovery of spermatogenesis following cancer therapy. Bone marrow-derived mesenchymal stem cells (BMSCs) possess the potential to differentiate or trans-differentiate into multi-lineage cells, secrete paracrine factors to recruit the resident stem cells to participate in tissue regeneration, or fuse with the local cells in the affected region. In this study, we tested whether spermatogenically-induced BMSCs can restore spermatogenesis after administration of an anticancer drug. Allogeneic BMSCs were co-cultured in conditioned media derived from cultured testicular Sertoli cells in vitro, and then induced stem cells were transplanted into the seminiferous tubules of a busulfan-induced azoospermatic rat model for 8 weeks. The in vitro induced BMSCs exhibited specific spermatogonic gene and protein markers, and after implantation the donor cells survived and located at the basement membranes of the recipient seminiferous tubules, in accordance with what are considered the unique biological characteristics of spermatogenic stem cells. Molecular markers of spermatogonial stem cells and spermatogonia (Vasa, Stella, SMAD1, Dazl, GCNF, HSP90α, integrinβ1, and c-kit) were expressed in the recipient testis tissue. No tumor mass, immune response, or inflammatory reaction developed. In conclusion, BMSCs might provide the potential to trans-differentiate into spermatogenic-like-cells, enhancing endogenous fertility recovery. The present study indicates that BMSCs might offer alternative treatment for the patients with azoospermatic infertility after cancer chemotherapy.

Role of Nitric Oxide Synthase in Bladder Pathologic Remodeling and Dysfunction Resulting From Partial Outlet Obstruction

OBJECTIVES To investigate the relationship between nitric oxide synthase (NOS) and oxidative stress and pathologic remodeling in the partial obstructed bladder of a rat model. METHODS We surgically established partial bladder outlet obstruction (PBOO) in 2 groups of rats and allowed it to persist for 3-6 weeks. Normal and sham-operated rats served as the controls. Each group contained 6 rats for a total of 24 rats. Cystometry was used to evaluate the bladder function. The bladders were removed, and histopathologic measurements were performed to evaluate bladder hypertrophy and fibrosis and NOS immunolocalization. Biochemical measurements were used to evaluated NOS mRNA and activity and the oxidative stress level. RESULTS The obstructed rats experienced significant increases in bladder weight, muscle hypertrophy, and deposits of collagen fibers compared with the normal and sham-operated groups. PBOO debilitated bladder contractibility, increased the residual urine volume and voiding interval, decreased the voiding volume, and caused poor bladder emptying, with an increased residual urine volume and decompensated bladder in the PBOO rats at 6 weeks. The elevation in malondialdehyde and reduction in superoxide dismutase activity in the PBOO rats suggested that oxidative stress injury occurred in the obstructed bladder. Lower inducible NOS and endothelial NOS (eNOS) mRNA expression was demonstrated through quantitative polymerase chain reaction. In particular, eNOS was significantly downregulated in the PBOO rats compared with the normal and sham-operated rats. The normal and PBOO bladder tissues did not express detectable levels of neuronal NOS mRNA or exhibit neuronal NOS immunoreactivity. The total NOS activity had decreased progressively in the PBOO groups in conjunction with the significantly decreased eNOS activity compared with that in the normal and sham-operated groups. CONCLUSIONS These findings suggest that decreases in NOS activity and expression (mainly of eNOS) concomitant with increases in reactive oxygen species generation represent the underlying pathogenic mechanism of obstructed bladder remodeling and dysfunction.

Laparoscopic Orchiopexy for Treating Inguinal Canalicular Palpable Undescended Testis

BACKGROUND AND PURPOSE This study investigated the safety and efficacy of using the minimally invasive operation of laparoscopic orchiopexy to treat palpable inguinal canalicular undescended testes. PATIENTS AND METHODS Laparoscopic orchiopexy was performed on 90 Chinese patients (103 testes) with inguinal canalicular palpable undescended testes. Patients with testes that were nonpalpable, ectopic, retractable, or palpable but distal to the external ring were excluded. Patients in the study ranged from 8 months to 6 years old (mean age: 17 months). Of the 103 testes undergoing operation, 26.7% were on the left side of the body and 58.9% were on the right; 14.4% of the patients had bilateral undescended testes. Laparoscopic techniques were used by the same surgeon to move the spermatic vessels and transfer the testis into the scrotum. RESULTS All 103 testes were successfully descended by laparoscopy. In the first 46 unilateral cases, the operation took significantly longer for the first 15 patients than the next 31, which were completed in 32.7 +/- 5.2 min. Of all 90 patients, a complication was encountered in only one, and this occurred at the beginning of the surgeons learning curve. Of 77 unilateral undescended testes, a patent processes vaginalis was found in 90.3% of the cases on the ipsilateral side and 15.6% on the contralateral side. All of the testes maintained an adequate size and intrascrotal position with no atrophy or recurrent inguinal hernia during a follow-up of 6 to 12 months. CONCLUSIONS The laparoscopic approach to orchiopexy is a safe way to descend the inguinal canalicular palpable testis. It offers several advantages of a minimally invasive technique and yield effective results.

The first case of renal lipoma in a child

Lipoma of the kidney is a rare benign renal tumor that previously had been reported only in adults. We present a case of this tumor in a 2-year-old boy. Serial imaging studies revealed a tumor with high fat content arising from the right kidney. Radical nephrectomy was performed for tumor excision. Macroscopically, the tumor consisted of a yellow fatty mass, which was surrounded by a thin fibrous capsule. The tumor was about 600 g, and the kidney was compressed laterally by the tumor. Microscopically, the tumor consisted of large fat cells that did not express human melanoma black-45 (HMB-45). It was diagnosed as a renal lipoma. Postoperatively, there has been no recurrence of tumor in the 10 months since the surgical excision.

Diagnosis and treatment of urethral prolapse in children: 16 years’ experience with 89 Chinese girls

Abstract Objective: To review our experience and results in the diagnosis and treatment of urethral prolapse (UP) in Chinese girls. Patients and methods: We conducted a retrospective chart review of 89 consecutive girls (aged <16 years) with UP and without other complications, who received treatment for UP from January 1999 to January 2015 (a study period of 16 years) at the Children’s Hospital of Chongqing Medical University, China. Data analysed included: age, symptoms, clinical findings, predisposing factors, management, and outcomes. Results: The presenting symptoms in the 89 girls were: mass (54 girls), bleeding (34), and dysuria/straining at micturition (one). In all, 14 patients received conservative treatment as their symptoms were mild, and 75 were successfully treated by excision of the prolapsed urethral mucosa or ligation over a Foley catheter, as their symptoms were severe and recurred too frequently to be managed conservatively. The mean postoperative length of stay for ligation was 7.76 days and for excision was 4.57 days. Ligation over a Foley catheter had a longer hospital stay. Conclusions: UP is a rare condition occurring in prepubertal girls, evidenced by a urethral mass and bleeding. Increased physician awareness and early recognition of UP avoids unnecessary examinations and patient anxiety.

A 22-year retrospective study: educational update and new referral pattern of age at orchidopexy.

To determine the current age at orchidopexy in China and whether changing targets have altered practice, as research suggesting progressive deterioration in an undescended testis (UDT) has led to the reduction in the target age for orchidopexy to 6–12 months but it is still unknown whether changing targets have altered practice.