Mock circulatory loop applications for testing cardiovascular assist devices and in vitro studies.

The mock circulatory loop (MCL) is an in vitro experimental system that can provide continuous pulsatile flows and simulate different physiological or pathological parameters of the human circulation system. It is of great significance for testing cardiovascular assist device (CAD), which is a type of clinical instrument used to treat cardiovascular disease and alleviate the dilemma of insufficient donor hearts. The MCL installed with different types of CADs can simulate specific conditions of clinical surgery for evaluating the effectiveness and reliability of those CADs under the repeated performance tests and reliability tests. Also, patient-specific cardiovascular models can be employed in the circulation of MCL for targeted pathological study associated with hemodynamics. Therefore, The MCL system has various combinations of different functional units according to its richful applications, which are comprehensively reviewed in the current work. Four types of CADs including prosthetic heart valve (PHV), ventricular assist device (VAD), total artificial heart (TAH) and intra-aortic balloon pump (IABP) applied in MCL experiments are documented and compared in detail. Moreover, MCLs with more complicated structures for achieving advanced functions are further introduced, such as MCL for the pediatric application, MCL with anatomical phantoms and MCL synchronizing multiple circulation systems. By reviewing the constructions and functions of available MCLs, the features of MCLs for different applications are summarized, and directions of developing the MCLs are suggested.

Synergism Between Multi-Pseudomonas and Cutinase for Biodegradation of Crude Oil-Based Derivatives.

Polyethylene terephthalate (PET) as one of the main crude oil-based derivatives, produces a significant amount of waste that is difficult to degrade. Currently, microbial degradation of PET is an eco-friendly, efficient, and economical method. This study was conducted to propose a novel screening strategy for PET-degrading bacteria, and evaluate their degradation efficiency of PET. Two strains, Pseudomonas nitroreducens S8 and Pseudomonas monteilii S17, were isolated and could utilize PET as a carbon source by co-culture. The combined use of both bacteria gave a synergistic effect on the disruption of the PET surface through colonization behavior, which could enhance the subsequent degradation of PET. Its time of reaching a peak value of PET degradation rate (94.5% at 6 d) was 2 days earlier than these of single bacteria. A similar synergistic effect was also observed in the metabolization of PET monomers, and the metabolic rate was expressed as 82.4% of bis (2-hydroxyethyl) terephthalate (BHET), 64.0% of mono (2-hydroxyethyl) terephthalate (MHET), and 20.0% of terephthalic acid (TPA), respectively. This study is novel in showing the degradation of PET waste by combinations of bacterial pretreatment and enzymatic treatment, which can be a promising method.

Kidney cancer cells secrete IL-8 to activate Akt and promote migration of mesenchymal stem cells.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent adult stem cells that have the capability of homing to cancer cells. Thus, MSCs play an important role in the development, metastasis, and drug resistance of cancers. The mechanisms underlying the homing of MSCs in kidney cancer are still poorly understood. METHODS: In the present study, enzyme-linked immunosorbent assay was used to measure the level of IL-8 in patients with kidney cancer and in the culture medium of kidney cancer cells. Immunofluorescence staining and reverse transcription polymerase chain reaction were utilized to explore the main receptor for IL-8 in MSCs. Transwell migration assay was performed to measure the migration ability of MSCs and Western blot test was performed to test the activation of signaling pathways. RESULTS: The serum level of IL-8 was markedly increased in patients with kidney cancer, and 2 kidney cancer cell lines were found to secrete IL-8. MSCs had high expression of the IL-8 receptor (CXCR2). Blocking IL-8 or CXCR2 could decrease the migration ability of MSCs. IL-8 could significantly increase Akt phosphorylation in MSCs. CONCLUSIONS: Kidney cancer cells secrete IL-8 to activate the Akt signaling pathway via CXCR2 on MSCs, inducing the migration of MSCs, which may be one of the important mechanisms underlying the homing of MSCs in kidney cancer.

Intravesical hyaluronidase causes chronic cystitis in a rat model: a potential model of bladder pain syndrome/interstitial cystitis.

OBJECTIVES: To determine whether a potential rat model of bladder pain syndrome could be developed through long-term intermittent intravesical hyaluronidase. METHODS: A total of 64 female Sprague-Dawley rats were divided into a control group, a low-dose hyaluronidase (1 mg/mL) group, a high-dose hyaluronidase (4 mg/mL) group and a hyaluronic acid-treated group. Hyaluronidase was given intravesically three times a week for 1 month. Hyaluronic acid (0.5 mL, 0.8 mg/mL) was introduced intravesically to hyaluronidase-treated rats' bladders. Histological changes, cystometry, nociceptive behaviors, and messenger ribonucleic acid levels of inflammatory factors were evaluated and compared between groups. RESULTS: All hyaluronidase-treated rats showed chronic inflammation and fibrosis, increased and activated mast cells, thinned bladder epithelium with abnormal expressions of uroplakin III and zonula occluden-1, and increased levels of interleukin-6 and intercellular adhesion molecule-1 messenger ribonucleic acid. However, the inflammatory score and levels of interleukin-6 and intercellular adhesion molecule-1 were more significant in the high-dose hyaluronidase group than in the low-dose hyaluronidase group (P < 0.01). Furthermore, hyaluronidase-treated rats showed markedly decreased intercontraction intervals, bladder capacity and increased sensitivity to pain compared with controls (P < 0.01). Hyaluronic acid treatment significantly decreased the inflammatory level, number of mast cells, sensitivity to pain, levels of interleukin-6 and intercellular adhesion molecule-1, and increased intercontraction intervals and bladder capacity (P < 0.01). CONCLUSIONS: Long-term intermittent intravesical hyaluronidase could develop a severe chronic cystitis with diffused fibrosis accompanied by altered histology and bladder function. This chronic cystitis rat model can resemble the clinical and histopathological features of human bladder pain syndrome, and might be a potential valuable model for investigation of this troublesome disease.

MicroRNA-335 acts as a candidate tumor suppressor in prostate cancer.

MicroRNA-335 (miR-335) acts as a tumor suppressor or a tumor promoter in different human malignancies. However, the involvement of miR-335 in prostate cancer (PCa) is still unclear. The purpose of this study was to investigate the functional and clinical significance of miR-335 in PCa. miR-335 expression in 3 PCa cell lines (LNCaP/DU145/PC3) and in 20 clinical PCa tissues were detected by real-time quantitative reverse transcriptase-PCR compared with corresponding controls. The function of miR-335 was investigated for cell proliferation, invasion and migration in PCa cells transfected with agents containing EGFP-miR-335 expression vector. Additionally, miR-335 expression in 104 clinical PCa tissues was detected by in situ hybridization. Its assocaitions with clinicopathological features and prognosis in patients with PCa were also determined. miR-335 was significantly down-regulated in PCa cell lines than in the normal prostate cell line (P < 0.01). With the similar results in vitro, the reduced expression of miR-335 was also found in human PCa tissues comparing with paired adjacent benign prostate tissues (P < 0.05). Moreover, the increased expression of miR-335 suppressed cell proliferation, invasion and migration of PCa cell lines in vitro. Turning to its clinical significance, the low expression of miR-335 was significantly associated with high Gleason Score (P = 0.04), advanced clinical stage (P = 0.04), and positive metastasis (P = 0.02), but not with prognosis in PCa patients. Our data demonstrated for the first time the inhibitory effect of miR-335 on cell proliferation and invasion for PCa cells. The loss of this microRNA might be associated with clinical progression of PCa patients.

Percutaneous nephrolithotomy in semisupine position: a modified approach for renal calculus.

Conventional percutaneous nephrolithotomy (PCNL) is usually performed in a prone position, which compresses the thorax and results in difficulty in rescue during operation. When PCNL is performed in a supine position, the flank renal puncture area is limited, so it is difficult to treat disseminated and complex renal calculi. Herein, we introduce a modified semisupine position for performing PCNL, which has numerous benefits as well as safe and effective. Between May 2002 and May 2009, a total of 452 patients with renal calculi were treated with semisupine PCNL. The patient was placed in 45° semisupine position during the procedure, with the affected flank arched as much as possible. In this series, no one converted to open surgery. The average operating time was (115.2 ± 44.5) min. Single tract PCNL was performed for 80.97% of the cases, two tracts 13.94%, three tracts 4.65%, and four tracts 0.44%. The upper, middle, and lower calix tracts accounted for 12.1, 63.0, and 24.9%, of procedures, respectively. Stone-free rate was 85.7% overall, 92.2% for single calculus (83/90), and 72.9% for staghorn calculi (78/107). Major postoperative complications occurred in 3.3% of the cases. This study demonstrated PCNL in a semisupine position is an effective alternative for treating renal calculi, which combines the advantages of PCNL in a prone position, and PCNL in a supine position. The semisupine position allows easier irrigation of stone fragments, is more comfortable for the patient, and facilitates monitoring of anesthesia.

[Application of modified single port laparoscopic radical cystoprostatectomy and orthotopic ileal neobladder].

OBJECTIVE: To evaluated the feasibility and therapeutic effect of laparoscopic-endoscopic single-site surgery (LESS) for radical cystoprostatectomy and orthotopic ileal neobladder. METHODS: Between November 2008 and August 2009, 8 male patients with bladder cancer underwent modified single port laparoscopic cystoprostatectomy and orthotopic ileal neobladder with a home-made multichannel port made up of two stretchable rings and a surgical glove with trocars and valves attached to its fingers. A 4 - 5 cm midline incision was made in lower abdomen and the multichannel port placed into this incision. Laparoscopic instrument was extended through the multichannel port. Another port was placed at the umbilicus site for laparoscope. The investigators performed the modified single port transperitoneal technique neobladder extracorporeally and urethro-pouch anastomosis under laparoscopy with a slipknot running suture technique. The perioperative and postoperative data were collected and analyzed prospectively. RESULTS: In all cases, no conversion into conventional laparoscopic or open surgery was necessary. The mean operative duration, including extended lymph node dissection, was 399 min (range: 355 - 455 min). Mean estimated blood loss was 154 ml (range: 90 -210 ml). The mean postoperative hospital stay was 15 d (range: 14 - 18 d). No peri-operative mortality was reported. One case had delirium 2 days postoperatively and there was no port-related complication. The pathological report confirmed surgical margins were tumor-free for all cases. The average number of removed lymph node was 20. The mean follow-up period was 6.1 months (range: 2.0 -10.0 months). All patients remained disease-free until the last follow-up. CONCLUSIONS: With a reduction of 4 ports, modified single port laparoscopic radical cystectomy with orthotopic ileal neobladder is technically feasible with a low complication rate. Our initial outcome is encouraging, but additional work and a further follow-up are warranted to critically compare the oncological outcome with open surgery.

Structural, electronic, and magnetic properties of boron nitride nanotubes filled with iron nanowires.

Under GGA, the structural, electronic, and magnetic properties of Fe(n) nanowire encapsulated in BNNTs have been investigated systematically using the first-principles PAW potential within DFT. We find that the initial shapes (quadratic-prismatic Fe wire and cylindrical (8,8) BNNT) are preserved without any visible changes and no one relative rotation is taken place after optimization for the thin nanowires encapsulated inside BNNTs, and the formation processes of such systems are exothermic due to the weaken interactions between them. The magnetic moments analyses show that no magnetization is found on the B and N atoms, but a significant enhancement of the magnetic moments is found for Fe(n) @ (8,8) systems, especially for thin nanowires encapsulated in (8,8) BNNT due to increased ratio of the surface atoms with less coordination number compared to bulk Fe, and very weak influence of outer nanotubes leading to their magnetic moments are similar to those of the freestanding nanowires. Both the total density of states (DOS) and charge density analyses show that the spin polarization and the magnetic moment of Fe(n) @ (8,8) systems come solely from the Fe(n) nanowire, implying the Fe5 @ (8,8) and Fe9 @ (8,8) systems can be applied to the circuits that demand preferential transport of electrons with a specific spin.

[Inhibition and significance of pigment epithelium-derived factor in the development and metastasis of prostate cancer].

OBJECTIVE: To study the inhibition and significance of pigment epithelium-derived factor (PEDF) in the development and metastasis of prostate cancer. METHODS: The expression of PEDF was examined in the normal prostate tissue, benign prostatic hyperplasia, prostate cancer tissue and prostate cancer cell lines, PC-3 and Lncap by immunohistochemical SP method and Western blot. In combination with clinical data, statistical analysis was performed to evaluate the relation of the expression level of PEDF in prostate cancer and the relationship between different histological grades of prostate cancer. RESULTS: In normal prostate tissue and benign prostate tissue, the expression of PEDF were elevated and it was far higher than the prostate cancer and prostate cancer cell line. The expression of PEDF and the pathological grade of prostate cancer were related to the differentiated carcinoma of prostate tissue, and the expression level of PEDF in poorly differentiated carcinoma below the highly differentiated carcinoma of prostate cancer. In metastatic prostate cancer, the expression of PEDF was lower than that of prostate cancer without metastasis (12% vs 43.1%). CONCLUSION: The expression of PEDF and the incidence of prostate cancer have a negative correlation. The lower grade of prostate cancer cells, the less the tissue expression of PEDF and the higher tendency of invasion and metastasis.

[Laparoscopic radical cystectomy with orthotopic ileal neobladder: report of 108 cases].

OBJECTIVE: To analyze the effects, complication, and outcome of laparoscopic radical cystectomy. METHODS: 108 patients with bladder cancer, 96 males and 12 females, aged 61 (36 - 81) underwent laparoscopic radical cystectomy with orthotopic ileal neobladder. Five-port transperitoneal approach was applied. The surgical procedure included standard laparoscopic pelvic lymphadenectomy, radical resection of bladder, extracorporeal formation of ileal pouch; extracorporeal implantation of ureters; and laparoscopic urethra-neobladder anastomosis. Erectile nerve sparing procedure was performed for 26 cases. The patients were followed up for 1 - 53 months. RESULTS: The median operation time was 330 min, and the median blood loss was 320 ml. Conversion to open surgery was not necessary in any of the patients. There was no peri-operative mortality. The complication rate was 18.5% (20/108). Surgical margins were tumor free for all cases. The day-time and night-time continence rates were 90.7% and 82.6% respectively in 6 months postoperatively. 10 of the 26 patients undergoing erectile nerve-sparing procedure had potency for intercourse. Follow-up showed 5 cases with local recurrence, 1 case with trocar site seeding and 6 cases with distant metastasis, 8 of the patients died of tumor-related disease and 3 died of diseases not related to tumor. CONCLUSION: Laparoscopic radical cystectomy with extracorporeal formation of orthotopic ileal neobladder is a feasible technique with low morbidity and acceptable neobladder function.

Laparoscopic radical cystectomy with orthotopic ileal neobladder in the female: report of 14 cases.

BACKGROUND: Bladder carcinoma is the most common malignant urological tumor in China. We present our preliminary experience and results of laparoscopic radical cystectomy (LRC) with orthotopic ileal neobladder in female patients with bladder carcinoma. METHODS: From February 2003 to February 2008, 14 female patients with bladder carcinoma underwent LRC with orthotopic ileal neobladder. Nine of these patients underwent hysterectomy and ovariectomy, and the other 5 had preservation of the uterus and ovarian appendage. Standard bilateral pelvic lymphadenectomy was followed by radical cystectomy that was completed laparoscopically with hysterectomy and ovariectomy when needed. The tumor was removed by a 4 - 5 cm lower midline abdominal incision, followed by the construction of ileal neobladder and the extracorporeal anastomosis of ureter-neobladder. The neobladder was anastomosed to the urethral stump under a laparoscope. RESULTS: The mean operative time and blood loss in the 14 patients were 350.2 minutes and 349.8 ml, respectively. Postoperative complications included uretero-pouch anastomotic stricture in 1 patient and pouch-vaginal fistula in 1 patient. Follow-up time of all patients ranged from 3 to 60 months, and 12 patients were followed up for more than 6 months and achieved micturition in half a year. One patient had occasional day-time urinary incontinence and 2 had night-time incontinence. Two patients who had undergone hysterectomy and ovariectomy had voiding difficulties after one year, which was treated by intermittent self-catheterization. The mean volume of the neobladder and the residual urine were 333.6 ml and 31.2 ml, respectively. Surgical margins were tumor free for all patients. One patient had bone metastasis and died 11 months after the operation. CONCLUSIONS: LRC with orthotopic ileal neobladder in female patients is a technically feasible, safe and mini-invasive procedure with a low morbidity and acceptable neobladder function. Long-term follow-up is required to confirm the neobladder function and oncological outcomes.

[Compare of laparoscopic and open surgery for radical cystectomy with orthotopic ileal neobladder].

OBJECTIVE: To compare the clinical therapeutic effect and complications of laparoscopic radical cystectomy with orthotopic ileal neobladder (LRC-INB) with open radical cystectomy with orthotopic ileal neobladder (ORC-INB). METHODS: A total of 171 patients were evaluated, including 63 cases with ORC-INB and 108 cases with LRC-INB from June 1994 to May 2007 at our institution. The parameters analyzed included perioperative data, postoperative complications, new bladder function and effect of tumor control. RESULTS: There was no significant difference in demographic characteristics of patients between these 2 groups. The mean operating time was 330 min in the LRC group and 310 min in the ORC group (P > 0.05). The mean blood loss was 320 ml in the LRC group and 1100 ml in ORC group (P < 0.001). The mean oral intake after operation was 2.4 days for LRC group and 4.5 days for ORC group (P < 0.001). No perioperative death was occurred in both groups. The complication rate was 18.5% in LRC group, while 30.0% in ORC group (P < 0.05). Twelve months after operation, the day-time and night-time continence rate were 90.7% and 82.6% for the LRC group, 88.3% and 81.6% for the ORC group respectively (P > 0.05). There was no significant difference of VOL, pressure and residual urine volume (RUV) of neobladder between these 2 groups. Surgical margin were tumor free for 107 cases except one T4 case in laparoscopic group had positive margin (P > 0.05). The mean number of removed lymph node were 12 and 8 in LRC and ORC group respectively (P < 0.05). The 2 years tumor free survival rate of the same stage or grade was no significant different (P > 0.05). CONCLUSIONS: LCR had advantages of less blood loss, shorter oral intake time, less postoperative complications, comparable continent rate and short-term tumor control with ORC. Long-term follow up is needed to confirm the oncological outcome.

[Screening and characterization of human phage Fab antibody gene to prostate specific membrane antigen].

OBJECTIVE: To screen and characterize the variable region gene about prostate specific membrane antigen (PSMA) of the Chinese Fab fragment, and to establish a new approach to researches on PSMA and prostate gene therapy. METHODS: We used purified PSMA protein as antigen, stuck it on the ELISA plate and scanned the phage Fab fragment antibody library by phage display technology. After five cycles of "absorbing-elution-amplification", we got the Fab fragment phage antibody of PSMA with high antigen binding ability and specificity, and tested it with immunodetection and sequencing. RESULTS: The sequence of Fd fragment was 696 base pairs encoding 232 amino-acid residues, with 98% homological similarity to the human immunoglobulin gamma chain, while the light chain was constructed by 630 base pairs encoding 210 amino-acid residues, with 93% homological similarity to kappa chain. CONCLUSION: Using phage display technology, we obtained the gene sequence of Fab antibody fragment specific to PSMA, and the antibody gene has the classic structural features of immunoglobulin light chain and heavy chain. The coding output of the antibody gene has the specificity and immunological competence to PSMA.

[Needle laparoscopic varicocelectomy].

OBJECTIVE: We evaluated our method and effects of needle laparoscopic varicocelectomy for the treatment of varicocele. METHODS: 72 patients (105 lateral) diagnosed varicocele were performed laparoscopic varicocelectomy under epidural combined intravenous anesthesia from Feb, 2003 to Apr, 2005. Two 2 mm incisions and one 5 mm incision were made on the midline of lower abdomen, by which two 2 mm trocars and one 5 mm trocar were introduced. Vessel-sealing device (Ligasure) was used to seal the internal spermatic veins. RESULTS: All operations were completed successfully. Mean operation time was 15 minutes unilateral and 21 minutes bilateral. The patients were hospitalized for 3 to 5 days after procedure. Follow-up was scheduled for 6 to 12 months and there was no recurrence. CONCLUSION: Needle laparoscopic varicocelectomy gives favorable effect with minimal invasion, rapid recovery, which is the best choice for the treatment of varicocele.

[Identification of response element gene sequence for non-steroid hormone transcription factors for the activation and up-regulation of L-plastin expression in prostate cancer].

OBJECTIVE: To search and identify the non-steroid receptor binding cis-acting elements in the L-plastin promoter in prostate cancer, and the correlative regulation pathway and transcription factors. METHODS: On the basis of construction of the L-plastin promoter luciferase vectors which were removed the steroid hormone receptor AR and ER binding elements, the promoter on the vector was nest-deleted by Exonuclease III and the relative luciferase plasmids were constructed. Transfected these twelve plasmids into prostate cancer cell line LNCaP under dihydrotestosterone-stimulated situation or not and test the intensity of luciferase, then we got the regulation message of every 200 bp part of the promoter in prostate cancer. After the analysis of relative programme, we got the possible regu- lation pathway of non-steroid hormone transcription factors. After removing the possible transcription factors binding site sequence by site-specific mutagenesis, the changes luciferase of activities proved our reasoning. RESULTS: We succeed in segmental deletion of the L-plastin promoter, and constructing the relative plasmids containing part L-plastin promoter on luciferase vector pGL3-basic. After testing the luciferase activities of constructed plasmids, we found the sequence from 206 to 1 of L-plastin promoter had significant luciferase activity. The software TRANSFECT showed that there were binding elements for transcription factors AP-4 at seq-198 to 192 and SP-1 at seq-54 to 41 on the short part promoter (206 to 1). The recombinant plasmids deleted the AP-4 and SP-1 binding elements had lower luciferase activity than the wild-type. CONCLUSION: There are some other non-steroid hormone pathway to regulate the expression of L-plastin except the steroid hormone pathway in prostate cancer. The main binding sites of the non-steroid hormone regulator lies in the sequence from 206 to 1. Transcription factors AP4 and SP-1 may up-regulated the expression of L-plastin by binding these sites.

Laparoscopic radical cystectomy with orthotopic ileal neobladder: report of 33 cases.

BACKGROUND: The laparoscopic radical cystectomy (LRC) with orthotopic ileal neobladder is now applied to treat invasive bladder cancer, however, it has not been well codified and illustrated. We describe in this paper a technique step by step that we have developed in 33 patients and achieved excellent results. METHODS: The surgical procedure can be divided into eight steps: laparoscopic pelvic lymphadenectomy and mobilization of the distal ureters; exposing Denonvillier's space and the posterior aspect of prostate; exposing retropubic space and anterior surface of the bladder; dividing the lateral pedicles of the bladder and the prostate; dividing the apex of the prostate; extracorporeal formation of the ileal pouch; extracorporeal implantation of the ureters; and laparoscopic urethra-neobladder anastomosis. This operation was performed in 33 patients, 29 males and 4 females, with muscle invasive bladder cancer between December 2002 and September 2004. RESULTS: The operating time was 5.5-8.5 hours with an average of 6.5 hours; the estimated blood loss was 200-1000 ml with an average of 460 ml. The surgical margins of the bladder specimen were negative in all patients. There was no evidence of local recurrence at follow-up of 1-21 months in all the patients. However lymph node metastases were found in one case at 9 months postoperatively. Most of patients achieved urine control 1 to 3 months after surgery. The daytime continence rate was 94% (31 cases) and nighttime continence rate was 88% (29 cases). Urodynamic evaluation was performed between 3 and 6 months postoperatively for all cases. The mean value of neobladder capacity was (296 +/- 37) ml. The mean value of maximum flow rate was (18.7 +/- 7.1) ml/s. The mean residual urine volume was (32 +/- 19) ml. In all cases, excretory urography at 1 to 2 months postoperatively demonstrated slightly dilated upper urinary tracts without ureteral obstruction, which resolved at follow up. Cystography showed neobladders being similar in shapes to normal. Two small ureteral nipples with intermittently efflux of urine were observed at cystoscopy in most patients. Postoperative complications occurred in 6 of 33 patients (18%), including pouch leakage in 2 cases, pelvic infection in 1, partial small bowel obstruction in 2 and neobladder-vaginal fistula in 1. CONCLUSIONS: The LRC with orthotopic ileal neobladder is a feasible option for bladder cancer when radical cystectomy is indicated. The extracorporeal formation of the ileal pouch and ureteral implantation through a small lower midline incision can simplify the complexity of the procedures, shorten the duration of surgery and reduce the medical expenses.