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2.
Eur Urol ; 81(4): 385-393, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34789393

ABSTRACT

BACKGROUND: It is hypothesised that simulation enhances progression along the initial phase of the surgical learning curve. OBJECTIVE: To evaluate whether residents undergoing additional simulation, compared to conventional training, are able to achieve proficiency sooner with better patient outcomes. DESIGN, SETTING, AND PARTICIPANTS: This international, multicentre, randomised controlled trial recruited 94 urology residents with experience of zero to ten procedures and no prior exposure to simulation in ureterorenoscopy, selected as an index procedure. INTERVENTION: Participants were randomised to simulation or conventional operating room training, as is the current standard globally, and followed for 25 procedures or over 18 mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The number of procedures required to achieve proficiency, defined as achieving a score of ≥28 on the Objective Structured Assessment of Technical Skill (OSATS) scale over three consecutive operations, was measured. Surgical complications were evaluated as a key secondary outcome. This trial is registered at www.isrctn.com as ISCRTN 12260261. RESULTS AND LIMITATIONS: A total of 1140 cases were performed by 65 participants, with proficiency achieved by 21 simulation and 18 conventional participants over a median of eight and nine procedures, respectively (hazard ratio [HR] 1.41, 95% confidence interval [CI] 0.72-2.75). More participants reached proficiency in the simulation arm in flexible ureterorenoscopy, requiring a lower number of procedures (HR 0.89, 95% CI 0.39-2.02). Significant differences were observed in overall comparison of OSATS scores between the groups (mean difference 1.42, 95% CI 0.91-1.92; p < 0.001), with fewer total complications (15 vs 37; p = 0.003) and ureteric injuries (3 vs 9; p < 0.001) in the simulation group. CONCLUSIONS: Although the number of procedures required to reach proficiency was similar, simulation-based training led to higher overall proficiency scores than for conventional training. Fewer procedures were required to achieve proficiency in the complex form of the index procedure, with fewer serious complications overall. PATIENT SUMMARY: This study investigated the effect of simulation training in junior surgeons and found that it may improve performance in real operating settings and reduce surgical complications for complex procedures.


Subject(s)
Internship and Residency , Simulation Training , Clinical Competence , Computer Simulation , Humans , Learning Curve , Simulation Training/methods
3.
Eur Urol Open Sci ; 22: 3-8, 2020 Dec.
Article in English | MEDLINE | ID: mdl-34337472

ABSTRACT

BACKGROUND: Postoperative readmission rates following radical cystectomy remain significant. Early identification of emerging complications could potentially allow for immediate institution of therapy. OBJECTIVE: To intensify postoperative patient-physician communication via a cellphone-based health care application (CHA) and to evaluate its potential for early detection of complications. DESIGN SETTING AND PARTICIPANTS: This was a pilot study involving 18 radical cystectomy patients. During the first 30 d, patients received a push cellphone notification twice a week requesting data input into the CHA. This was reduced to once a week from day 31 to day 90. De-identified recorded data were reviewed by the surgeon involved. If deemed necessary, patients were contacted by the surgeon via telephone to obtain more detailed clinical information. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Descriptive statistics were used. RESULTS AND LIMITATIONS: Of the 18 patients enrolled, all completed the 90-d reporting period. On two occasions, interventions were necessary on the basis of data recorded on the CHA. One neobladder patient was given antibiotic therapy for pyelonephritis. Another patient reported weight loss and nausea with clinical suspicion of metabolic acidosis, and his sodium bicarbonate and fluid intake were increased. Limitations include the small number of cases from a single low-volume center. CONCLUSIONS: CHA-based monitoring of clinical parameters within the crucial 90-d postoperative period following radical cystectomy provides meaningful information. In this pilot study, two potential readmissions were possibly avoided on the basis of recorded basic vital signs and early intervention. PATIENT SUMMARY: Besides regular clinic follow-up visits after radical cystectomy, additional aids such as a cellphone-based health care application can provide treating physicians with relevant clinical information and may help to identify imminent deviations from normal postoperative recovery at an early stage.

4.
JCI Insight ; 2(2): e89560, 2017 01 26.
Article in English | MEDLINE | ID: mdl-28138557

ABSTRACT

Bladder outlet obstruction (BOO) induces significant organ remodeling, leading to lower urinary tract symptoms accompanied by urodynamic changes in bladder function. Here, we report mRNA and miRNA transcriptome sequencing of bladder samples from human patients with different urodynamically defined states of BOO. Patients' miRNA and mRNA expression profiles correlated with urodynamic findings. Validation of RNA sequencing results in an independent patient cohort identified combinations of 3 mRNAs (NRXN3, BMP7, UPK1A) and 3 miRNAs (miR-103a-3p, miR-10a-5p, miR-199a-3p) sufficient to discriminate between bladder functional states. All BOO patients shared cytokine and immune response pathways, TGF-ß and NO signaling pathways, and hypertrophic PI3K/AKT signaling pathways. AP-1 and NFkB were dominant transcription factors, and TNF-α was the top upstream regulator. Integrated miRNA-mRNA expression analysis identified pathways and molecules targeted by differentially expressed miRNAs. Molecular changes in BOO suggest an increasing involvement of miRNAs in the control of bladder function from the overactive to underactive/acontractile states.


Subject(s)
MicroRNAs/metabolism , RNA, Messenger/metabolism , Urinary Bladder Neck Obstruction/genetics , Urinary Bladder, Overactive/genetics , Urinary Bladder, Underactive/genetics , Aged , Aged, 80 and over , Biomarkers , Bone Morphogenetic Protein 7/genetics , Case-Control Studies , Cytokines/metabolism , Gene Expression Profiling , Gene Regulatory Networks , Humans , Male , Metabolic Networks and Pathways , Middle Aged , NF-kappa B/metabolism , Nerve Tissue Proteins/genetics , Nitric Oxide/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Transcription Factor AP-1/metabolism , Transforming Growth Factor beta/metabolism , Urinary Bladder Neck Obstruction/metabolism , Urinary Bladder Neck Obstruction/physiopathology , Urinary Bladder, Overactive/metabolism , Urinary Bladder, Overactive/physiopathology , Urinary Bladder, Underactive/metabolism , Urinary Bladder, Underactive/physiopathology , Urodynamics , Uroplakin Ia/genetics
5.
Int J Surg Protoc ; 3: 1-6, 2017.
Article in English | MEDLINE | ID: mdl-31851756

ABSTRACT

INTRODUCTION: Pancreatic resection is the only curative treatment for pancreatic cancer. Due to tumor cachexia most patients present with a weight loss at the time of diagnosis. Postoperatively the weight loss is often intensified. Tumor cachexia has an influence on the post-operative morbidity and mortality and on the overall survival. Complementary nutrition has a benefit on the mentioned issues. Needle catheter jejunostomy (NCJ) offers a well-tolerated and safe way for additional nutrition therapy. Until today, the optimal length of postoperative supplementary nutrition has not been evaluated. METHODS AND ANALYSIS: The study is designed as a randomized controlled trial to compare the effect of complementary nutritional support until discharge and until 8-weeks after discharge for patients after pancreaticoduodenectomy (PD). The primary endpoint is the comprehensive complications index assessed 12 weeks postoperatively. The grading of the complications will be performed by a blinded assessor. The secondary endpoints are: quality of life, a nutritional assessment and the assessment of the effect on adjuvant therapies and 5-year survival. Follow-up visits are planned 1-, 3-, 6-, 12- and 60 month postoperatively. A total sample size of 140 patients was determined for the analysis of the primary endpoint. The confirmatory analysis will be performed based on the intention-to-treat principle. ETHICS AND DISSEMINATION: The ethics committee of the University of Bern reviewed and approved this study on 22.08.2016 (KEK BE 322/14). The trial was registered in the German Clinical Trial Register (DRKS00010237) on 25.08 2016. The present trial is the first study comparing short- and long-term complementary nutritional support after PD in randomized controlled study. The results will allow a postoperative nutritional therapy after PD based on high quality data. The results will be presented at relevant surgical conferences and written publications of the short-term results and long-term oncologic results are planned within surgical journals.

6.
Am J Surg ; 213(4): 711-717, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27519151

ABSTRACT

BACKGROUND: In laparoscopic distal pancreatectomy (LapDP), the pancreas is accessed in a greater curvature approach (GCA). The lesser curvature approach (LCA) has been proposed in underweight patients. The study investigated the feasibility of LCA irrespective of the body mass index (BMI). METHODS: This retrospective study included consecutive patients scheduled to undergo LapDP with the LCA. A matched cohort (1:1) underwent GCA. Spleen preservation was performed using the Warshaw technique. Splenic perfusion was intraoperatively assessed by indocyanine green (ICG) angiography. RESULTS: The LCA with LapDP was successful in 12/15 patients. In 2 cases, LCA had to be converted to GCA and in 1 patient to open surgery. The cohorts were well matched in sex (P = 1.0), age (P = .67), indication (P = 1.0), and median BMI (23.4 kg/m2 vs 24.8 kg/m2, P = .41). Splenic preservation was achieved in 14/15 patients with LCA and 4/15 patients with GCA (P = .33). In all LCA cases, ICG angiography indicated sufficient spleen perfusion. The groups had similar morbidity (P = 1.0) and hospital stay (P = .74). CONCLUSIONS: LCA was feasible in 80% irrespective of BMI and provided an excellent field of exposure. ICG angiography was feasible in the Warshaw technique. Its reliability should be evaluated in prospective studies.


Subject(s)
Laparoscopy , Pancreatectomy/methods , Aged , Angiography , Case-Control Studies , Coloring Agents , Feasibility Studies , Female , Humans , Indocyanine Green , Male , Middle Aged , Organ Sparing Treatments , Pancreatic Neoplasms/surgery , Postoperative Complications , Retrospective Studies , Spleen/blood supply , Spleen/diagnostic imaging
7.
Investig Clin Urol ; 57(5): 309-15, 2016 09.
Article in English | MEDLINE | ID: mdl-27617311

ABSTRACT

Urethral stricture after radiation therapy for localized prostate cancer is a delicate problem as the decreased availability of tissue healing and the close relation to the sphincter complicates any surgical approach. We here review the pathophysiology, dosimetry, and the disease specific aspects of urethral strictures after radiotherapy. Moreover we discuss different treatment option such as direct vision internal urethrotomy as well as techniques for open reconstruction with and without tissue transfer.


Subject(s)
Prostatic Neoplasms/radiotherapy , Radiation Injuries/etiology , Urethral Stricture/etiology , Humans , Male , Radiation Injuries/diagnosis , Radiation Injuries/physiopathology , Radiation Injuries/surgery , Radiotherapy/adverse effects , Radiotherapy Dosage , Urethral Stricture/diagnosis , Urethral Stricture/physiopathology , Urethral Stricture/surgery
8.
BJU Int ; 117(2): 253-9, 2016 Feb.
Article in English | MEDLINE | ID: mdl-25307941

ABSTRACT

OBJECTIVE: To update our previous analysis of the clinical and pathological impact of the change in the submission of lymphadenectomy specimens from en bloc to 13 separate anatomically defined packets, which took place at the University of Southern California in May 2002, and to determine whether lymph node (LN) packeting resulted in any change in oncological outcomes. PATIENTS AND METHODS: A total of 846 patients who underwent radical cystectomy (RC) with super-extended LN dissection for cTxN0M0 bladder cancer between January 1996 and December 2007 were identified. Specimens of 376 patients were sent en bloc (group 1), and specimens of 470 patients were sent in 13 separate anatomical packets (group 2). RESULTS: The pathological tumour stage distribution and the proportion of LN-positive patients (group 1: 82 patients [22%] versus group 2: 99 patients [21%]; P = 0.80) were similar between the two groups: the median [range] number of total LNs identified increased significantly (group 1: 32 [10-97] versus group 2: 65 [10-179]; P < 0.001). LN density decreased (group 1, 11% versus group 2, 4%; P = 0.005). The median [range] number of positive LNs removed was similar (group 1: 0 [0-30] versus group 2: 0 [0-97]; P = 0.87). No nodal stage shift was observed. The 5-year overall survival (group 1: 58% versus group 2: 59%; P = 0.65) and recurrence-free survival rates (group 1: 68% versus group 2: 70%; P = 0.57) were similar. CONCLUSIONS: The incidence of patients with positive LNs remained unchanged, regardless of how the LN specimen was submitted. Submitting 13 separate nodal packets significantly increased the total LN yield, but did not result in a significant increase in the number of positive LNs or a consecutive nodal stage shift and did not affect oncological outcomes. Based on these results LN density is not an accurate prognosticator.


Subject(s)
Carcinoma, Transitional Cell/pathology , Cystectomy , Lymph Node Excision , Lymph Nodes/pathology , Pelvis/pathology , Specimen Handling , Urinary Bladder Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Carcinoma, Transitional Cell/mortality , Humans , Lymphatic Metastasis , Middle Aged , Neoplasm Staging , Reproducibility of Results , Retrospective Studies , Specimen Handling/methods , Survival Analysis , Urinary Bladder Neoplasms/mortality
9.
EMBO Rep ; 16(9): 1219-32, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26206718

ABSTRACT

In human prostate cancer, the microRNA biogenesis machinery increases with prostate cancer progression. Here, we show that deletion of the Dgcr8 gene, a critical component of this complex, inhibits tumor progression in a Pten-knockout mouse model of prostate cancer. Early stages of tumor development were unaffected, but progression to advanced prostatic intraepithelial neoplasia was severely inhibited. Dgcr8 loss blocked Pten null-induced expansion of the basal-like, but not luminal, cellular compartment. Furthermore, while late-stage Pten knockout tumors exhibit decreased senescence-associated beta-galactosidase activity and increased proliferation, the simultaneous deletion of Dgcr8 blocked these changes resulting in levels similar to wild type. Sequencing of small RNAs in isolated epithelial cells uncovered numerous miRNA changes associated with PTEN loss. Consistent with a Pten-Dgcr8 association, analysis of a large cohort of human prostate tumors shows a strong correlation between Akt activation and increased Dgcr8 mRNA levels. Together, these findings uncover a critical role for microRNAs in enhancing proliferation and enabling the expansion of the basal cell compartment associated with tumor progression following Pten loss.


Subject(s)
PTEN Phosphohydrolase/metabolism , Prostatic Neoplasms/genetics , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Animals , Disease Progression , Gene Deletion , Gene Expression Regulation, Neoplastic , Humans , Male , Mice , Mice, Knockout , MicroRNAs/genetics , PTEN Phosphohydrolase/deficiency , PTEN Phosphohydrolase/genetics , Prostate/physiopathology , Prostatic Intraepithelial Neoplasia/genetics , Prostatic Neoplasms/metabolism
10.
BJU Int ; 113(1): 65-9, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23937628

ABSTRACT

OBJECTIVE: To evaluate oncological outcomes of patients with carcinoma in situ (CIS) exclusively at radical cystectomy (RC) and no previous history of ≥T1 disease. PATIENTS AND METHODS: Patients undergoing RC with curative intent for CIS between 1971 and 2008 at the University of Southern California were included if they met all the following criteria: (i) pathological CIS-only disease at RC, (ii) preoperative clinical stage cCIS and/or cCIS + cTa, and (iii) no previous history of lamina propria invasion (≥pT1). Kaplan-Meier plots were used to estimate the probabilities of recurrence-free survival (RFS) and overall survival (OS). RESULTS: Of the 1964 consented patients 52 met the inclusion criteria with a median (range) follow-up of 8.5 (0.008-34) years. A median (range) of 36 (10-95) lymph nodes were identified per patient but no metastases found. Estimated 5- and 10-year RFS rates were 94% and 90%, respectively and estimated 5- and 10-year OS rates were 85% and 66%, respectively. Different mechanisms of recurrence were found in four (8%) patients after a median (range) interval of 2.4 (0.6-7.1) years. While two patients had metachronous recurrence within the urinary tract, the first of the other two had early systemic recurrence and the second late local recurrence. CONCLUSIONS: We noticed excellent outcomes after RC for CIS-only disease. However, patients may have synchronous and/or develop metachronous tumours, as well as local and/or distant/systemic recurrence that can be cured but may also lead to fatal outcomes.


Subject(s)
Carcinoma in Situ/mortality , Carcinoma in Situ/surgery , Cystectomy , Lymph Nodes/pathology , Neoplasm Recurrence, Local/mortality , Urinary Bladder Neoplasms/mortality , Urinary Bladder Neoplasms/surgery , Adult , Aged , Aged, 80 and over , California/epidemiology , Carcinoma in Situ/pathology , Cystectomy/mortality , Disease-Free Survival , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/surgery , Retrospective Studies , Risk Factors , Treatment Outcome , Urinary Bladder Neoplasms/pathology
11.
BJU Int ; 111(2): 289-95, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23253774

ABSTRACT

OBJECTIVE: To evaluate the antibiotic treatment regime in patients with indwelling JJ stents, the benefits and disadvantages of a peri-interventional antibiotic prophylaxis were compared with those of a continuous low-dose antibiotic treatment in a prospective randomised trial. PATIENTS AND METHODS: In all, 95 patients were randomised to either receive peri-interventional antibiotic prophylaxis during stent insertion only (group A, 44 patients) or to additionally receive a continuous low-dose antibiotic treatment until stent removal (group B, 51). Evaluations for urinary tract infections (UTI), stent-related symptoms (SRSs) and drug side-effects were performed before stent insertion and consecutively after 1, 2 and 4 weeks and/or at stent withdrawal. All patients received a peri-interventional antibiotic prophylaxis with 1.2 g amoxicillin/clavulanic acid. Amoxicillin/clavulanic acid (625 mg) once daily was administered for continuous low-dose treatment (group B). Primary endpoints were the overall rates of UTIs and SRSs. Secondary endpoints were the rates and severity of drug side-effects. RESULTS: Neither the overall UTI rates (group A: 9% vs group B: 10%), nor the rates of febrile UTIs (group A: 7% vs group B: 6%) were different between the groups. Similarly, SRS rates did not differ (group A: 98% vs group B: 96%). Antibiotic side-effect symptoms were to be increased in patients treated with low-dose antibiotics. CONCLUSION: A continuous antibiotic low-dose treatment during the entire JJ stent-indwelling time does not reduce the quantity or severity of UTIs and has no effect on SRSs either compared with a peri-interventional antibiotic prophylaxis only.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Antibiotic Prophylaxis/methods , Prosthesis-Related Infections/prevention & control , Stents , Urinary Tract Infections/prevention & control , Urolithiasis/surgery , Adult , Aged , Aged, 80 and over , Endoscopy/methods , Female , Humans , Male , Middle Aged , Prospective Studies , Prosthesis Implantation/methods , Stents/adverse effects , Surveys and Questionnaires , Young Adult
12.
Transl Androl Urol ; 2(3): 242-53, 2013 Sep.
Article in English | MEDLINE | ID: mdl-26816738

ABSTRACT

Prostate cancer (P-Ca) remains a leading cause of cancer-related death in men. Lately, increasing evidence for a hierarchically organized cancer stem cell (CSC) model emerged for different tumors entities, including P-Ca. CSCs are defined by several characteristics including self-renewal, pluripotency and tumorigenicity and are thought to be responsible for tumor recurrence, metastasis and cancer related death. In this review we discuss the recent research in the field of CSCs, its limitations and therapeutical implications in general and specifically in P-Ca.

13.
Am J Clin Exp Immunol ; 1(2): 70-89, 2012 Nov 30.
Article in English | MEDLINE | ID: mdl-23304658

ABSTRACT

Profiling miRNA expression in cells that directly contribute to human disease pathogenesis is likely to aid the discovery of novel drug targets and biomarkers. However, tissue heterogeneity and the limited amount of human diseased tissue available for research purposes present fundamental difficulties that often constrain the scope and potential of such studies. We established a flow cytometry-based method for isolating pure populations of pathogenic T cells from bronchial biopsy samples of asthma patients, and optimized a high-throughput nano-scale qRT-PCR method capable of accurately measuring 96 miRNAs in as little as 100 cells. Comparison of circulating and airway T cells from healthy and asthmatic subjects revealed asthma-associated and tissue-specific miRNA expression patterns. These results establish the feasibility and utility of investigating miRNA expression in small populations of cells involved in asthma pathogenesis, and set a precedent for application of our nano-scale approach in other human diseases. The microarray data from this study (Figure 7) has been submitted to the NCBI Gene Expression Omnibus (GEO; http://ncbi.nlm.nih.gov/geo) under accession no. GSE31030.

14.
J Vis Exp ; (54)2011 Aug 03.
Article in English | MEDLINE | ID: mdl-21847076

ABSTRACT

The broad involvement of miRNAs in critical processes underlying development, tissue homoeostasis and disease has led to a surging interest among the research and pharmaceutical communities. To study miRNAs, it is essential that the quantification of microRNA levels is accurate and robust. By comparing wild-type to small RNA deficient mouse embryonic stem cells (mESC), we revealed a lack of accuracy and robustness in previous published multiplex qRT-PCR techniques. Here, we describe an optimized method, including purifying away excessive primers from previous multiplex steps before singleplex real time detection, which dramatically increases the accuracy and robustness of the technique. Furthermore, we explain how performing the technique on a microfluidic chip at nanoliter volumes significantly reduces reagent costs and permits time effective high throughput miRNA expression profiling.


Subject(s)
Embryonic Stem Cells/chemistry , MicroRNAs/chemistry , Reverse Transcriptase Polymerase Chain Reaction/methods , Animals , Embryonic Stem Cells/physiology , Mice , MicroRNAs/genetics , MicroRNAs/isolation & purification , Microfluidic Analytical Techniques , Nanotechnology/instrumentation , Nanotechnology/methods , Reverse Transcriptase Polymerase Chain Reaction/instrumentation
15.
Cancer Res ; 71(2): 550-60, 2011 Jan 15.
Article in English | MEDLINE | ID: mdl-21098088

ABSTRACT

Recent prostate-specific antigen-based screening trials indicate an urgent need for novel and noninvasive biomarker identification strategies to improve the prediction of prostate cancer behavior. Noncoding microRNAs (miRNA) in the serum and plasma have been shown to have potential as noninvasive markers for physiologic and pathologic conditions. To identify serum miRNAs that diagnose and correlate with the prognosis of prostate cancer, we developed a multiplex quantitative reverse transcription PCR method involving the purification of multiplex PCR products followed by uniplex analysis on a microfluidics chip to evaluate 384 human miRNAs. Using Dgcr8 and Dicer knockout (small RNA-deficient) mouse ES cells as the benchmark, we confirmed the validity of our technique and uncovered a considerable lack of accuracy in previously published methods. Profiling 48 sera from healthy men and untreated prostate cancer patients with differing CAPRA scores, we identified miRNA signatures that allow us to diagnose cancer patients and correlate with a prognosis. These serum signatures include oncogenic and tumor-suppressive miRNAs, suggesting functional roles in prostate cancer progression.


Subject(s)
MicroRNAs/blood , Microfluidic Analytical Techniques/methods , Prostatic Neoplasms/blood , Prostatic Neoplasms/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Case-Control Studies , Humans , Male , MicroRNAs/genetics , Prognosis , Prostatic Neoplasms/diagnosis
16.
Curr Biol ; 20(3): 271-7, 2010 Feb 09.
Article in English | MEDLINE | ID: mdl-20116247

ABSTRACT

Dicer, which is required for the processing of both microRNAs (miRNAs) and small interfering RNAs (siRNAs), is essential for oocyte maturation [1, 2]. Oocytes express both miRNAs and endogenous siRNAs (endo-siRNAs) [3, 4]. To determine whether the abnormalities in Dicer knockout oocytes during meiotic maturation are secondary to the loss of endo-siRNAs and/or miRNAs, we deleted Dgcr8, which encodes an RNA-binding protein specifically required for miRNA processing. In striking contrast to Dicer, Dgcr8-deficient oocytes matured normally and, when fertilized with wild-type sperm, produced healthy-appearing offspring, even though miRNA levels were reduced to similar levels as Dicer-deficient oocytes. Furthermore, the deletion of both maternal and zygotic Dgcr8 alleles did not impair preimplantation development, including the determination of the inner cell mass and trophectoderm. Most surprisingly, the mRNA profiles of wild-type and Dgcr8 null oocytes were essentially identical, whereas Dicer null oocytes showed hundreds of misregulated transcripts. These findings show that miRNA function is globally suppressed during oocyte maturation and preimplantation development and that endo-siRNAs, rather than miRNAs, underlie the Dicer knockout phenotype in oocytes.


Subject(s)
Blastocyst/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Oocytes/metabolism , Animals , DEAD-box RNA Helicases/deficiency , DEAD-box RNA Helicases/genetics , Endoribonucleases/deficiency , Endoribonucleases/genetics , Female , Male , Mice , Mice, Knockout , Models, Biological , Oocytes/growth & development , Phenotype , Pregnancy , Proteins/genetics , Proteins/metabolism , RNA Processing, Post-Transcriptional , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA-Binding Proteins , Ribonuclease III
17.
Urol Oncol ; 26(6): 581-9, 2008.
Article in English | MEDLINE | ID: mdl-18818107

ABSTRACT

Following the initial identification of hematopoietic tumor stem cells, such cells were also found in several solid tumor types. In urology, cancer stem cells have only been found in prostate tumors so far. The concept and detection of tumor stem cells rely heavily on findings derived from stem cell research. Therefore, in addition to identifying and characterizing urologic tumor stem cells, research in uro-oncology should also aim at better understanding the stem-cell biology of urologic organs. Insights in similarities and differences gleaned from these studies could be used to develop strategies for targeted destruction of tumor stem cells while sparing the physiological stem cells. The main target of future curative therapies in uro-oncology must therefore be the central, immortal head of the Hydra, the tumor stem cell.


Subject(s)
Neoplastic Stem Cells/physiology , Urologic Neoplasms/pathology , Animals , Cell Differentiation , Cell Division , Hedgehog Proteins/physiology , Humans , Male , PTEN Phosphohydrolase/physiology , Prostatic Neoplasms/pathology , Prostatic Neoplasms/therapy , Receptors, Notch/physiology , Signal Transduction , Urinary Bladder Neoplasms/pathology , Urinary Bladder Neoplasms/therapy , Urologic Neoplasms/therapy
18.
Radiology ; 229(3): 847-54, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14657319

ABSTRACT

PURPOSE: To evaluate a self-expanding rhenium 188 (188Re) radiochemically labeled radioactive stent in sheep. MATERIALS AND METHODS: A self-expanding nitinol stent (30 mm in length, 8 mm in diameter) coated with a functionalized polymer layer was radiolabeled with 188Re. Fifty prostheses, 25 of which were radioactive (mean radioactivity, 20 MBq +/- 3.8 [SD]) and 25 of which were nonradioactive, were implanted into the external iliac arteries of 25 sheep. Stent patency was assessed with angiography. Neointimal formation was assessed with intravascular ultrasonography and histologic examination 1 month (in all sheep) and 3 months (in 12 sheep) after implantation. The results were analyzed by using repeated-measures analysis of variance with two repeated factors and paired t tests for comparison at each measuring point. RESULTS: All stents were placed successfully. Data in one animal had to be excluded from the study. After 3 months, a mean neointimal area reduction of 70 mm2 +/- 55 (SD) was observed inside the radioactive stents, and a mean lumen reduction of 126 mm2 +/- 39 was observed inside the nonradioactive control stents (P =.022). An edge effect was observed in the radioactive stents in that they showed an amount of neointimal formation at the edges that was similar to that seen in control stents. This neointimal formation accounted for the maximum lumen loss in the vascular segment with the stent. CONCLUSION: As compared with a nonradioactive stent, a beta particle-emitting stent, through endovascular irradiation, significantly inhibits neointimal formation inside the stent but not at the stent edges.


Subject(s)
Alloys , Radioisotopes/therapeutic use , Rhenium/therapeutic use , Stents , Tunica Intima/radiation effects , Animals , Coronary Restenosis/prevention & control , Disease Models, Animal , Follow-Up Studies , Prosthesis Implantation , Sheep , Tunica Intima/pathology
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