Proteomic and phosphoproteomic characterization of cardiovascular tissues after long term exposure to simulated space radiation.

Introduction: It may take decades to develop cardiovascular dysfunction following exposure to high doses of ionizing radiation from medical therapy or from nuclear accidents. Since astronauts may be exposed continually to a complex space radiation environment unlike that experienced on Earth, it is unresolved whether there is a risk to cardiovascular health during long-term space exploration missions. Previously, we have described that mice exposed to a single dose of simplified Galactic Cosmic Ray (GCR5-ion) develop cardiovascular dysfunction by 12 months post-radiation. Methods: To investigate the biological basis of this dysfunction, here we performed a quantitative mass spectrometry-based proteomics analysis of heart tissue (proteome and phosphoproteome) and plasma (proteome only) from these mice at 8 months post-radiation. Results: Differentially expressed proteins (DEPs) for irradiated versus sham irradiated samples (fold-change ≥1.2 and an adjusted p-value of ≤0.05) were identified for each proteomics data set. For the heart proteome, there were 87 significant DEPs (11 upregulated and 76 downregulated); for the heart phosphoproteome, there were 60 significant differentially phosphorylated peptides (17 upregulated and 43 downregulated); and for the plasma proteome, there was only one upregulated protein. A Gene Set Enrichment Analysis (GSEA) technique that assesses canonical pathways from BIOCARTA, KEGG, PID, REACTOME, and WikiPathways revealed significant perturbation in pathways in each data set. For the heart proteome, 166 pathways were significantly altered (36 upregulated and 130 downregulated); for the plasma proteome, there were 73 pathways significantly altered (25 upregulated and 48 downregulated); and for the phosphoproteome, there were 223 pathways significantly affected at 0.1 adjusted p-value cutoff. Pathways related to inflammation were the most highly perturbed in the heart and plasma. In line with sustained inflammation, neutrophil extracellular traps (NETs) were demonstrated to be increased in GCR5-ion irradiated hearts at 12-month post irradiation. NETs play a fundamental role in combating bacterial pathogens, modulating inflammatory responses, inflicting damage on healthy tissues, and escalating vascular thrombosis. Discussion: These findings suggest that a single exposure to GCR5-ion results in long-lasting changes in the proteome and that these proteomic changes can potentiate acute and chronic health issues for astronauts, such as what we have previously described with late cardiac dysfunction in these mice.

Video analysis of ex vivo beating hearts during preservation on the TransMedics® organ care system.

Background: Reliable biomarkers for assessing the viability of the donor hearts undergoing ex vivo perfusion remain elusive. A unique feature of normothermic ex vivo perfusion on the TransMedics® Organ Care System (OCS™) is that the donor heart is maintained in a beating state throughout the preservation period. We applied a video algorithm for an in vivo assessment of cardiac kinematics, video kinematic evaluation (Vi.Ki.E.), to the donor hearts undergoing ex vivo perfusion on the OCS™ to assess the feasibility of applying this algorithm in this setting. Methods: Healthy donor porcine hearts (n = 6) were procured from Yucatan pigs and underwent 2 h of normothermic ex vivo perfusion on the OCS™ device. During the preservation period, serial high-resolution videos were captured at 30 frames per second. Using Vi.Ki.E., we assessed the force, energy, contractility, and trajectory parameters of each heart. Results: There were no significant changes in any of the measured parameters of the heart on the OCS™ device over time as judged by linear regression analysis. Importantly, there were no significant changes in contractility during the duration of the preservation period (time 0-30 min, 918 ± 430 px/s; time 31-60 min, 1,386 ± 603 px/s; time 61-90 min, 1,299 ± 617 px/s; time 91-120 min, 1,535 ± 728 px/s). Similarly, there were no significant changes in the force, energy, or trajectory parameters. Post-transplantation echocardiograms demonstrated robust contractility of each allograft. Conclusion: Vi.Ki.E. assessment of the donor hearts undergoing ex vivo perfusion is feasible on the TransMedics OCS™, and we observed that the donor hearts maintain steady kinematic measurements throughout the duration.

Ex Vivo Gene Delivery to Porcine Cardiac Allografts Using a Myocardial-Enhanced Adeno-Associated Viral Vector.

Transplantation, the gold standard intervention for organ failure, is a clinical field that is ripe for applications of gene therapy. One of the major challenges in applying gene therapy to this field is the need for a method that achieves consistent and robust gene delivery to allografts. Normothermic ex vivo perfusion is a growing organ preservation method and a device for cardiac preservation was recently approved by the Food and Drug Administration (FDA) (Organ Care System, OCS™; TransMedics, Inc., Andover, MA); this device maintains donor hearts in a near physiologic state while they are transported from the donor to the recipient. This study describes the administration of recombinant adeno-associated viral vectors (rAAVs) during ex vivo normothermic perfusion for the delivery of transgenes to porcine cardiac allografts. We utilized a myocardial-enhanced AAV3b variant, SASTG, assessing its transduction efficiency in the OCS perfusate relative to other AAV serotypes. We describe the use of normothermic ex vivo perfusion to deliver SASTG carrying the Firefly Luciferase transgene to porcine donor hearts in four heterotopic transplant procedures. Durable and dose-dependent transgene expression was achieved in the allografts in 30 days, with no evidence of off-target transgene expression. This study demonstrates the feasibility and efficiency of delivering genes to a large animal allograft utilizing AAV vectors during ex vivo perfusion. These findings support the idea of gene therapy interventions to enhance transplantation outcomes.

Transvenous Endomyocardial Biopsy Technique for Intra-abdominal Heterotopic Cardiac Grafts.

The porcine intra-abdominal heterotopic heart transplantation model allows for the assessment of immunologic effects on cardiac transplantation without relying on the allograft to maintain hemodynamic support for the animal. Historically, allograft function and histology is monitored by physical exam, echocardiogram evaluation, percutaneous core biopsy, and open biopsy. We performed transvenous endomyocardial biopsies in three pigs that had undergone heterotopic heart implantation. We describe the procedure to be feasible and reproducible, and that histologic results from these biopsies correlated with those from corresponding tissue collected by surgical dissection at the time of allograft explantation. The ability to perform endomyocardial biopsies in the heterotopic heart transplantation model allows for serial non-invasive monitoring of allograft histology.

Late onset cardiovascular dysfunction in adult mice resulting from galactic cosmic ray exposure.

The complex and inaccessible space radiation environment poses an unresolved risk to astronaut cardiovascular health during long-term space exploration missions. To model this risk, healthy male c57BL/6 mice aged six months (corresponding to an astronaut of 34 years) were exposed to simplified galactic cosmic ray (GCR5-ion; 5-ion sim) irradiation at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratories (BNL). Multi-modal cardiovascular functional assessments performed longitudinally and terminally revealed significant impairment in cardiac function in mice exposed to GCR5-ion compared to unirradiated controls, gamma irradiation, or single mono-energetic ions (56Fe or 16O). GCR5-ion-treated mice exhibited increased arterial elastance likely mediated by disruption of elastin fibers. This study suggests that a single exposure to GCR5-ion is associated with deterioration in cardiac structure and function that becomes apparent long after exposure, likely associated with increased morbidity and mortality. These findings represent important health considerations when preparing for successful space exploration.

A Porcine Heterotopic Heart Transplantation Protocol for Delivery of Therapeutics to a Cardiac Allograft.

Cardiac transplantation is the gold standard treatment for end-stage heart failure. However, it remains limited by the number of available donor hearts and complications such as primary graft dysfunction and graft rejection. The recent clinical use of an ex vivo perfusion device in cardiac transplantation introduces a unique opportunity for treating cardiac allografts with therapeutic interventions to improve function and avoid deleterious recipient responses. Establishing a translational, large-animal model for therapeutic delivery to the entire allograft is essential for testing novel therapeutic approaches in cardiac transplantation. The porcine, heterotopic heart transplantation model in the intraabdominal position serves as an excellent model for assessing the effects of novel interventions and the immunopathology of graft rejection. This model additionally offers long-term survival for the pig, given that the graft is not required to maintain the recipient's circulation. The aim of this protocol is to provide a reproducible and robust approach for achieving ex vivo delivery of a therapeutic to the entire cardiac allograft prior to transplantation and provide technical details to perform a survival heterotopic transplant of the ex vivo perfused heart.

Prediction and Interpretation of Polymer Properties Using the Graph Convolutional Network.

We present machine learning models for the prediction of thermal and mechanical properties of polymers based on the graph convolutional network (GCN). GCN-based models provide reliable prediction performances for the glass transition temperature (T g), melting temperature (T m), density (ρ), and elastic modulus (E) with substantial dependence on the dataset, which is the best for T g (R 2 ∼ 0.9) and worst for E (R 2 ∼ 0.5). It is found that the GCN representations for polymers provide prediction performances of their properties comparable to the popular extended-connectivity circular fingerprint (ECFP) representation. Notably, the GCN combined with the neural network regression (GCN-NN) slightly outperforms the ECFP. It is investigated how the GCN captures important structural features of polymers to learn their properties. Using the dimensionality reduction, we demonstrate that the polymers are organized in the principal subspace of the GCN representation spaces with respect to the backbone rigidity. The organization in the representation space adaptively changes with the training and through the NN layers, which might facilitate a subsequent prediction of target properties based on the relationships between the structure and the property. The GCN models are found to provide an advantage to automatically extract a backbone rigidity, strongly correlated with T g, as well as a potential transferability to predict other properties associated with a backbone rigidity. Our results indicate both the capability and limitations of the GCN in learning to describe polymer systems depending on the property.

Comparison of Machine Learning Methods towards Developing Interpretable Polyamide Property Prediction.

Polyamides are often used for their superior thermal, mechanical, and chemical properties. They form a diverse set of materials that have a large variation in properties between linear to aromatic compounds, which renders the traditional quantitative structure-property relationship (QSPR) challenging. We use extended connectivity fingerprints (ECFP) and traditional QSPR fingerprints to develop machine learning models to perform high fidelity prediction of glass transition temperature (Tg), melting temperature (Tm), density (ρ), and tensile modulus (E). The non-linear model using random forest is in general found to be more accurate than linear regression; however, using feature selection or regularization, the accuracy of linear models is shown to be improved significantly to become comparable to the more complex nonlinear algorithm. We find that none of the models or fingerprints were able to accurately predict the tensile modulus E, which we hypothesize is due to heterogeneity in data and data sources, as well as inherent challenges in measuring it. Finally, QSPR models revealed that the fraction of rotatable bonds, and the rotational degree of freedom affects polyamide properties most profoundly and can be used for back of the envelope calculations for a quick estimate of the polymer attributes (glass transition temperature, melting temperature, and density). These QSPR models, although having slightly lower prediction accuracy, show the most promise for the polymer chemist seeking to develop an intuition of ways to modify the chemistry to enhance specific attributes.

The use of an inexpensive processing aid device (the Mouse PAD) to facilitate rodent tissue banking.

The generation of an experimental animal model often requires considerable investment of both time and money. Typically, investigators are interested in specific organs and when experimental animals are euthanized, tissues that are not the focus of the research project are discarded. However, the remaining tissues from these animals could provide valuable scientific information if efficient, error-proof and economical approaches to collect and biobank them were available. We have developed a device that, when incorporated into our tissue processing workflow, allows for high-throughput collection and processing of multiple rodent organ systems. This device, the mouse Processing Aid Device, or mouse PAD, helps to standardize organ collection and increase its efficiency.

A normothermic ex vivo organ perfusion delivery method for cardiac transplantation gene therapy.

Clinically, both percutaneous and surgical approaches to deliver viral vectors to the heart either have resulted in therapeutically inadequate levels of transgene expression or have raised safety concerns associated with extra-cardiac delivery. Recent developments in the field of normothermic ex vivo cardiac perfusion storage have now created opportunities to overcome these limitations and safety concerns of cardiac gene therapy. This study examined the feasibility of ex vivo perfusion as an approach to deliver a viral vector to a donor heart during storage and the resulting bio distribution and expression levels of the transgene in the recipient post-transplant. The influence of components (proprietary solution, donor blood, and ex vivo circuitry tubing and oxygenators) of the Organ Care System (OC) (TransMedics, Inc., Andover MA) on viral vector transduction was examined using a cell-based luciferase assay. Our ex vivo perfusion strategy, optimized for efficient Adenoviral vector transduction, was utilized to deliver 5 × 1013 total viral particles of an Adenoviral firefly luciferase vector with a cytomegalovirus (CMV) promotor to porcine donor hearts prior to heterotopic implantation. We have evaluated the overall levels of expression, protein activity, as well as the bio distribution of the firefly luciferase protein in a series of three heart transplants at a five-day post-transplant endpoint. The perfusion solution and the ex vivo circuitry did not influence viral vector transduction, but the serum or plasma fractions of the donor blood significantly inhibited viral vector transduction. Thus, subsequent gene delivery experiments to the explanted porcine heart utilized an autologous blood recovery approach to remove undesired plasma or serum components of the donor blood prior to its placement into the circuit. Enzymatic assessment of luciferase activity in tissues (native heart, allograft, liver etc.) obtained post-transplant day five revealed wide-spread and robust luciferase activity in all regions of the allograft (right and left atria, right and left ventricles, coronary arteries) compared to the native recipient heart. Importantly, luciferase activity in recipient heart, liver, lung, spleen, or psoas muscle was within background levels. Similar to luciferase activity, the luciferase protein expression in the allograft appeared uniform and robust across all areas of the myocardium as well as in the coronary arteries. Importantly, despite high copy number of vector genomic DNA in transplanted heart tissue, there was no evidence of vector DNA in either the recipient's native heart or liver. Overall we demonstrate a simple protocol to achieve substantial, global gene delivery and expression isolated to the cardiac allograft. This introduces a novel method of viral vector delivery that opens the opportunity for biological modification of the allograft prior to implantation that may improve post-transplant outcomes.

[E-Learning in bachelor-level nursing education in Germany and the role of the nurse educator - a Delphi survey]. / E-Learning in der hochschulischen Pflegeausbildung in Deutschland und die Rolle von Hochschullehrenden − eine Delphi-Erhebung.

E-Learning in bachelor-level nursing education in Germany and the role of the nurse educator - a Delphi survey Abstract. BACKGROUND: In addition to conventional face-to-face classes, e-learning is becoming more prevalent in tertiary-level nurse education. Its asynchronous, decentralized nature influences teaching and learning. AIM: This study examines current expert opinion on how e-learning is affecting tertiary-level nurse education and the role of the nurse educator. METHODS: In a 3-wave Delphi survey, nurse educators, nursing students / alumni, information and communications technology (ICT-) specialists and members of the scientific community were recruited as experts and asked to give their opinions regarding e-Learning and its effects on nurse education and the nurse educator's role. The null-round (R0) instrument comprised open questions. The R0-data were analyzed utilizing qualitative content analysis and then used in conjunction with the results of an earlier literature review to generate items for standardized follow up rounds (R1&2). The R1&2-instrument consists of 14 statements pertaining to e-learning and 13 statements pertaining to the nurse educator's role. Participants were asked to indicate the degree to which they agree with each statement. R1&2-data were analyzed using statistical methods. The means and medians for R1&2 were compared with each other. In addition, the response behavior of each individual participant was analyzed and assessed as assimilating, divergent, stable or inexplicable. RESULTS: The size of the expert panel was: R0 = 8, R1&2 = 15; total panel mortality was n = 2. The analysis of standardized data provides the following representation of expert opinion: Participants viewed the effectiveness of e-learning as being not only dependent upon the domain of the learning objective (i. e. cognitive, affective), but also upon the complexity of the subject matter. According to the experts, face-to-face interaction is paramount to successful learning. The experts also recognized e-learning's potential for facilitating cooperation between clinical and classroom settings, the continuity of teaching and learning, a better work-study-life balance, as well as knowledge transfer. Furthermore, the participants took the view that e-learning changes the nurse educator's role, requiring new / expanded didactical, pedagogical, administrative and technical competencies compared to traditional face-to-face teaching and learning. CONCLUSIONS: Nurse educators will need specific training to prepare them for their altered role. Blended learning offers more added value than pure online learning.

Solution-Phase Conformation and Dynamics of Conjugated Isoindigo-Based Donor-Acceptor Polymer Single Chains.

Conjugated polymers are the key material in thin-film organic optoelectronic devices due to the versatility of these molecules combined with their semiconducting properties. A molecular-scale understanding of conjugated polymers is important to the optimization of the thin-film morphology. We examine the solution-phase behavior of conjugated isoindigo-based donor-acceptor polymer single chains of various chain lengths using atomistic molecular dynamics simulations. Our simulations elucidate the transition from a rod-like to a coil-like conformation from an analysis of normal modes and persistence length. In addition, we find another transition based on the solvent environment, contrasting the coil-like conformation in a good solvent with a globule-like conformation in a poor solvent. Overall, our results provide valuable insights into the transition between conformational regimes for conjugated polymers as a function of both the chain length and the solvent environment, which will help to accurately parametrize higher level models.

Urinary Catheter Management for Nonurologists: A Resident Driven Educational Initiative.

INTRODUCTION: Prevention of catheter associated urinary tract infection relies on timely catheter removal and care of indwelling catheters. Educational and quality improvement initiatives to prevent catheter associated urinary tract infection should address the basics of urinary catheter placement and management. Internal medicine residents are an appropriate target for these efforts and they may lack formal training in these issues. We developed a resident driven orientation session that covers basic Foley catheter management principles called the TIPS (Troubleshooting, Indications and Practice Sessions) program. METHODS: Urology residents at our institution were queried on common consultations for urinary catheter related issues. The incoming intern internal medicine class at our institution completed a pre-TIPS survey that evaluated their baseline urological experience and knowledge. A 1-hour didactic session led by urology residents was followed by hands-on directed practice with mannequins. The web based survey was repeated 1 month later. RESULTS: Of the total of 60 residents 54 (90%) completed the initial survey. In medical school 38 of 54 residents (70%) had never rotated in urology. Upon repeating the survey at 1 month the response rate was 34 of 60 residents (57%). The proportion of residents confident in their ability to troubleshoot catheter problems increased from 50% to 88% (p <0.05). Knowledge of indications, clot retention and proper catheter technique also improved (p <0.05). CONCLUSIONS: A focused educational session about common urological catheter management scenarios resulted in improved internal medicine resident confidence in catheter troubleshooting and knowledge of basic urinary catheter placement indications. These educational sessions may be a method to improve nonurology resident education and awareness of common urological issues.

Preoperative Belladonna and Opium Suppository for Ureteral Stent Pain: A Randomized, Double-blinded, Placebo-controlled Study.

OBJECTIVE: To investigate whether the use of a belladonna and opium (B&O) rectal suppository administered immediately before ureteroscopy (URS) and stent placement could reduce stent-related discomfort. METHODS: A randomized, double-blinded, placebo-controlled study was performed from August 2013 to December 2014. Seventy-one subjects were enrolled and randomized to receive a B&O (15 mg/30 mg) or a placebo suppository after induction of general anesthesia immediately before URS and stent placement. Baseline urinary symptoms were assessed using the American Urological Association Symptom Score (AUASS). The Ureteral Stent Symptom Questionnaire and AUASS were completed on postoperative days (POD) 1, 3, and after stent removal. Analgesic use intraoperatively, in the recovery unit, and at home was recorded. RESULTS: Of the 71 subjects, 65 had treatment for ureteral (41%) and renal (61%) calculi, 4 for renal urothelial carcinoma, and 2 were excluded for no stent placed. By POD3, the B&O group reported a higher mean global quality of life (QOL) score (P = .04), a better mean quality of work score (P = .05), and less pain with urination (P = .03). The B&O group reported an improved AUASS QOL when comparing POD1 with post-stent removal (P = .04). There was no difference in analgesic use among groups (P = .67). There were no episodes of urinary retention. Age was associated with unplanned emergency visits (P <.00) and "high-pain" measure (P = .02) CONCLUSION: B&O suppository administered preoperatively improved QOL measures and reduced urinary-related pain after URS with stent. Younger age was associated with severe stent pain and unplanned hospital visits.

First in Human Clinical Trial of Ultrasonic Propulsion of Kidney Stones.

PURPOSE: Ultrasonic propulsion is a new technology using focused ultrasound energy applied transcutaneously to reposition kidney stones. We report what are to our knowledge the findings from the first human investigational trial of ultrasonic propulsion toward the applications of expelling small stones and dislodging large obstructing stones. MATERIALS AND METHODS: Subjects underwent ultrasonic propulsion while awake without sedation in clinic, or during ureteroscopy while anesthetized. Ultrasound and a pain questionnaire were completed before, during and after propulsion. The primary outcome was to reposition stones in the collecting system. Secondary outcomes included safety, controllable movement of stones and movement of stones less than 5 mm and 5 mm or greater. Adverse events were assessed weekly for 3 weeks. RESULTS: Kidney stones were repositioned in 14 of 15 subjects. Of the 43 targets 28 (65%) showed some level of movement while 13 (30%) were displaced greater than 3 mm to a new location. Discomfort during the procedure was rare, mild, brief and self-limited. Stones were moved in a controlled direction with more than 30 fragments passed by 4 of the 6 subjects who had previously undergone a lithotripsy procedure. The largest stone moved was 10 mm. One patient experienced pain relief during treatment of a large stone at the ureteropelvic junction. In 4 subjects a seemingly large stone was determined to be a cluster of small passable stones after they were moved. CONCLUSIONS: Ultrasonic propulsion was able to successfully reposition stones and facilitate the passage of fragments in humans. No adverse events were associated with the investigational procedure.

Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.

PURPOSE: Ultrasound is known to overestimate kidney stone size. We explored measuring the acoustic shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy. MATERIALS AND METHODS: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the acoustic shadow were measured by 4 operators blinded to the true size of the stone. RESULTS: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing error based on the shadow width was independent of depth. CONCLUSIONS: Shadow width was a more accurate measure of true stone size than a direct measurement of the stone in the ultrasound image (p <0.0001). The ultrasound imaging modality also impacted the measurement accuracy. All methods performed similarly for shadow size while harmonic imaging was the most accurate stone size modality. Overall 78% of the shadow sizes were accurate to within 1 mm, which is similar to the resolution obtained with clinical computerized tomography.

Renal Vasoconstriction Occurs Early During Shockwave Lithotripsy in Humans.

INTRODUCTION: In animal models, pretreatment with low-energy shock waves and a pause decreased renal injury from shockwave lithotripsy (SWL). This is associated with an increase in perioperative renal resistive index (RI). A perioperative rise is not seen without the protective protocol, which suggests that renal vasoconstriction during SWL plays a role in protecting the kidney from injury. The purpose of our study was to investigate whether there is an increase in renal RI during SWL in humans. MATERIALS AND METHODS: Subjects were prospectively recruited from two hospitals. All subjects received an initial 250 shocks at low setting, followed by a 2-minute pause. Treatment power was then increased. Measurements of the renal RI were taken before start of procedure, at 250, after 750, after 1500 shocks, and at the end of the procedure. A linear mixed-effects model was used to compare RIs at the different time points. RESULTS: Fifteen patients were enrolled. Average treatment time was 46 ± 8 minutes. Average RI at pretreatment, after 250, after 750, after 1500 shocks, and post-treatment was 0.67 ± 0.06, 0.69 ± 0.08, 0.71 ± 0.07, 0.73 ± 0.07, and 0.74 ± 0.06, respectively. In adjusted analyses, RI was significantly increased after 750 shocks compared with pretreatment (p = 0.05). CONCLUSION: Renal RI increases early during SWL in humans with the protective protocol. Monitoring for a rise in RI during SWL is feasible and may provide real-time feedback as to when the kidney is protected.

Tools to improve the accuracy of kidney stone sizing with ultrasound.

PURPOSE: Ultrasound (US) overestimates stone size when compared with CT. The purpose of this work was to evaluate the overestimation of stone size with US in an in vitro water bath model and investigate methods to reduce overestimation. MATERIALS AND METHODS: Ten human stones (3-12 mm) were measured using B-mode (brightness mode) US by a sonographer blinded to the true stone size. Images were captured and compared using both a commercial US machine and software-based research US device. Image gain was adjusted between moderate and high stone intensities, and the transducer-to-stone depth was varied from 6 to 10 cm. A computerized stone-sizing program was developed to outline the stone width based on a grayscale intensity threshold. RESULTS: Overestimation with the commercial device increased with both gain and depth. Average overestimation at moderate and high gain was 1.9±0.8 and 2.1±0.9 mm, respectively (p=0.6). Overestimation increased an average of 22% with an every 2-cm increase in depth (p=0.02). Overestimation using the research device was 1.5±0.9 mm and did not vary with depth (p=0.28). Overestimation could be reduced to 0.02±1.1 mm (p<0.001) with the computerized stone-sizing program. However, a standardized threshold consistent across depth, system, or system settings could not be resolved. CONCLUSION: Stone size is consistently overestimated with US. Overestimation increased with increasing depth and gain using the commercial machine. Overestimation was reduced and did not vary with depth, using the software-based US device. The computerized stone-sizing program shows the potential to reduce overestimation by implementing a grayscale intensity threshold for defining the stone size. More work is needed to standardize the approach, but if successful, such an approach could significantly improve stone-sizing accuracy and lead to automation of stone sizing.

Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones.

OBJECTIVE: To provide an update on a research device to ultrasonically reposition kidney stones transcutaneously. This article reports preclinical safety and effectiveness studies, survival data, modifications of the system, and testing in a stone-forming porcine model. These data formed the basis for regulatory approval to test the device in humans. MATERIALS AND METHODS: The ultrasound burst was shortened to 50 ms from previous investigations with 1-s bursts. Focused ultrasound was used to expel 2- to 5-mm calcium oxalate monohydrate stones placed ureteroscopically in 5 pigs. Additionally, de novo stones were imaged and repositioned in a stone-forming porcine model. Acute safety studies were performed targeting 2 kidneys (6 sites) and 3 pancreases (8 sites). Survival studies followed 10 animals for 1 week after simulated treatment. Serum and urine analyses were performed, and tissues were evaluated histologically. RESULTS: All ureteroscopically implanted stones (6/6) were repositioned out of the kidney in 14 ± 8 minutes with 13 ± 6 bursts. On average, 3 bursts moved a stone more than 4 mm and collectively accounted for the majority of relocation. Stones (3 mm) were detected and repositioned in the 200-kg stone-forming model. No injury was detected in the acute or survival studies. CONCLUSION: Ultrasonic propulsion is safe and effective in the porcine model. Stones were expelled from the kidney. De novo stones formed in a large porcine model were repositioned. No adverse effects were identified with the acute studies directly targeting kidney or pancreatic tissue or during the survival studies indicating no evidence of delayed tissue injury.

Role of maximal endoscopic resection before cystectomy for invasive urothelial bladder cancer.

INTRODUCTION/BACKGROUND: The aim of this study was to examine whether TUR of all visible endophytic tumors performed before RC, with or without NC, affects final pathologic staging. PATIENTS AND METHODS: We retrospectively reviewed data from patients with clinical T2-T4N0-1 urothelial carcinoma of the bladder who underwent RC at our institution between July 2005 and November 2011. Degree of TUR was derived from review of operative reports. We used multivariate logistic regression to assess the association of maximal TUR on pT0 status at time of RC. RESULTS: Of 165 eligible RC patients, 81 received NC. Reported TUR of all visible tumors was performed in 38% of patients who did not receive NC and 48% of NC patients (P = .19). Nine percent of patients who underwent maximal TUR and did not receive NC were pT0, whereas among NC patients, pT0 was seen in 39% and 19% of those with and without maximal TUR, respectively (P = .05). On multivariate analysis in all patients, maximal TUR was associated with a nonsignificant increased likelihood of pT0 status (odds ratio [OR], 2.03; 95% confidence interval [CI], 0.84-4.94), which was significant when we restricted the analysis to NC patients (OR, 3.17; 95% CI, 1.02-9.83). CONCLUSION: Maximal TUR of all endophytic tumors before NC is associated with complete pathologic tumor response at RC. Candidates for NC before RC should undergo resection of all endophytic tumors when feasible. Larger series are warranted to see if maximal TUR leads to improved overall and disease-specific survival.