A semiconductor 96-microplate platform for electrical-imaging based high-throughput phenotypic screening.

High-content imaging for compound and genetic profiling is popular for drug discovery but limited to endpoint images of fixed cells. Conversely, electronic-based devices offer label-free, live cell functional information but suffer from limited spatial resolution or throughput. Here, we introduce a semiconductor 96-microplate platform for high-resolution, real-time impedance imaging. Each well features 4096 electrodes at 25 µm spatial resolution and a miniaturized data interface allows 8× parallel plate operation (768 total wells) for increased throughput. Electric field impedance measurements capture >20 parameter images including cell barrier, attachment, flatness, and motility every 15 min during experiments. We apply this technology to characterize 16 cell types, from primary epithelial to suspension cells, and quantify heterogeneity in mixed co-cultures. Screening 904 compounds across 13 semiconductor microplates reveals 25 distinct responses, demonstrating the platform's potential for mechanism of action profiling. The scalability and translatability of this semiconductor platform expands high-throughput mechanism of action profiling and phenotypic drug discovery applications.

Assessments of Perfusion, Blood Flow, and Vascular Structure in Ambulatory Subjects: Guidance for Translational Research Scientists.

Research involving human subjects in ambulatory settings is a critical link in the chain comprising translational research, spanning preclinical research to human subject and patient cohort studies. There are presently a wide array of techniques and approaches available to investigators wishing to study blood flow, perfusion, and vascular structure and function in human subjects. In this multi-sectioned review, we discuss capillaroscopy, carotid intima-media thickness, flow-mediated dilation, laser Doppler flowmetry, near-infrared spectroscopy, peripheral arterial tonometry, pulse wave velocity, retinal fundus imaging, and vascular plethysmography. Each section contains a general overview and the physical basis of the technique followed by a discussion of the procedures involved and the necessary equipment, with attention paid to specific requirements or limitations. Subsequently, we detail which aspects of vascular function can be studied with a given technique, the analytical approach to the collected data, and the appropriate application and limitation(s) to the interpretation of the data collected. Finally, a modified scoping review provides a summary of how each assessment technique has been applied in previous studies. It is anticipated that this review will provide an efficient source of information and insight for preclinical investigators seeking to add translational aspects to their research programs.

Self-reported throwing volumes are not a valid tool for monitoring throwing loads in elite Australian cricket players: An observational cohort study.

OBJECTIVES: To determine the concurrent validity of player self-reported and independently observed throwing volume. Examine whether sex, playing position, or time to upload self-reported data post training influences the accuracy of self-reported throwing loads. DESIGN: Cross-sectional cohort study. METHODS: A total of 8 female and 18 male elite cricket players participated in the study. Overarm throws from 12 training sessions during the 2020-21 cricket year were observed. Player self-reported throwing volume data were retrieved post training, with the time difference between session completion and self-reported data upload recorded. RESULTS: A moderate positive correlation was found between self-reported and observed throwing loads (rho = 0.65), however only 22 % of players reported values within a 10 % level of error. Players reported a mean (SD) absolute inaccuracy of 11.17 (9.77) throws, and a mean (SD) relative inaccuracy of 24.76 (16.04) percent. Sex did not influence reporting accuracy (p = 0.41). Females tended to upload self-reported data the day of training, whereas men report the day following. Players who uploaded their data greater than one day after training were the most inaccurate with a mean relative inaccuracy of 36 %. CONCLUSIONS: While there is a clear relationship between observed and self-reported throwing volumes, the findings of this study question the validity of using player self-reported throwing load as a marker of true throwing loads with most players recording in excess of 10 % error. High performance staff and players should consider whether the current accuracy of self-reported throwing load justifies the additional reporting burden on the players during training.

Community organization factors affecting veteran participation in adaptive sports.

Objective: This study aims to describe United States military veteran participation in adaptive sports and to assess the demographic make-up and organizational characteristics of existing adaptive sports programs.Design: Prospective, cross-sectional survey.Setting: Community organizations with adaptive sports programs.Participants: 85 adaptive sports programs.Interventions: Nine question survey.Outcome Measures: Demographic data and sports offered by adaptive sports programs in the United States.Results: The survey response rate was 70%. The median number of total participants in an organization was 75 and the median number of veterans was 50. 76% of organizations had some degree of affiliation with a VAMC. Organizations affiliated with a VAMC are more likely to be rehabilitation centers, whereas community organizations with no VAMC affiliation are most commonly independent organizations with no rehabilitation component. Individuals of all ages participate in adaptive sports, with increasing participation associated with increasing age. Golf was the sport offered most commonly by adaptive sports programs in this survey. Low-contact sports were offered more often than high-contact sports, and the majority of programs offered adaptive sports year-round.Conclusions: Our results suggest that U.S. Military veterans represent a large proportion of the individuals participating in adaptive sports. Further research specifically focusing on factors veterans find desirable when considering participating in adaptive sports is indicated to identify programs that should be promoted, developed, and funded to increase veteran participation in adaptive sports.

Delayed coloanal anastomosis as a stoma-sparing alternative to immediate coloanal anastomosis: A systematic review and meta-analysis.

BACKGROUND: Recent clinical trials have demonstrated favorable outcomes associated with trans-anal colonic pull-through for rectal resection followed by delayed coloanal anastomoses (DCA), resulting in a resurgence in popularity of the technique. This meta-analysis aims to review existing literature to evaluate the postoperative complications associated with DCA, and to make comparisons with immediate coloanal anastomoses (ICA) after colorectal resection to assess the suitability of DCA as an alternative form of surgical treatment. METHODS: Medline and Embase databases were reviewed from inception until 31 July 2020 in accordance with PRISMA guidelines. Single-arm studies that involved patients undergoing DCA for benign or malignant causes were selected, and meta-analysis of proportions was conducted to determine the prevalence of postoperative complications following DCA. Comparative studies comparing postoperative outcomes between DCA and ICA were also included for comparative meta-analysis. RESULTS: Patients undergoing DCA were significantly less likely to require diverting stoma construction as compared to ICA (odds ratio [OR] = 0.04; confidence interval [CI]: 0.02-0.07; P < 0.001). Overall postoperative morbidity (OR = 0.50; 95% CI: 0.23-1.12; P = 0.09) and mortality (OR = 0.49, 95% CI: 0.12-1.98; P = 0.32) was comparable between DCA and ICA groups. No significant differences in perioperative complications, such as anastomotic leakage (OR = 0.42; 95% CI: 0.11-1.64; P = 0.21), postoperative ileus, pelvic abscesses, or sepsis, were noted between DCA and ICA. CONCLUSION: Our study shows no differences in complications or functional outcomes between DCA and ICA. Pooled analysis expectedly revealed a lower rate of diverting stoma in patients undergoing DCA. DCA is thus a safe alternative to current surgical practices where avoidance of a stoma is desired.

Strong nutrient-plant interactions enhance the stability of ecosystems.

Modular food web theory shows how weak energetic fluxes resulting from consumptive interactions plays a major role in stabilizing food webs in space and time. Despite the reliance on energetic fluxes, food web theory surprisingly remains poorly understood within an ecosystem context that naturally focuses on material fluxes. At the same time, while ecosystem theory has employed modular nutrient-limited ecosystem models to understand how limiting nutrients alter the structure and dynamics of food webs, ecosystem theory has overlooked the role of key ecosystem interactions and their strengths (e.g., plant-nutrient; R-N) in mediating the stability of nutrient-limited ecosystems. Here, towards integrating food web theory and ecosystem theory, we first briefly review consumer-resource interactions (C-R) highlighting the relationship between the structure of C-R interactions and the stability of food web modules. We then translate this framework to nutrient-based systems, showing that the nutrient-plant interaction behaves as a coherent extension of current modular food web theory; however, in contrast to the rule that weak C-R interactions tend to be stabilizing we show that strong nutrient-plant interactions are potent stabilizers in nutrient-limited ecosystem models.

Quantifying the rate of recurrence of postoperative Crohn's disease with biological therapy. A meta-analysis.

OBJECTIVE: Preventing the postoperative recurrence (POR) of Crohn's disease (CD) poses a significant challenge to clinicians. With the advent of biologics, various studies have observed a reduction of recurrence after surgery. Hence, we performed a systematic review and meta-analysis to identify the rate of POR at different time points in the era of biologic use. METHODS: We performed a literature search using Medline and Embase databases for studies investigating biologics in preventing the POR of CD. Data were extracted, and a single-arm meta-analysis with generalized linear mixed model and Clopper-Pearson method for confidence interval (CI) was performed to identify endoscopic, clinical and surgical recurrence rates at 6 months and 1, 2 and 5 years postoperatively. RESULTS: Altogether 24 studies were included in the meta-analysis. The endoscopic, clinical and surgical POR rate with the use of anti-tumor necrosis factor (TNF)-α agents at 1 year was 21.72% (95% CI 16.28%-28.37%), 13.06% (95% CI 8.18%-18.92%) and 3.76% (95% CI 1.37%-9.91%), respectively. The 5-year recurrence rate was 84.21% (95% CI 72.35%-91.57%) and 17.49% (95% CI 9.17%-30.80%) for endoscopic and surgical recurrence, respectively. Subgroup analyses at 1 year for the type of anti-TNF-α agent or the timing of initiation after surgery showed no significant difference in endoscopic, clinical and surgical recurrence rates. CONCLUSIONS: Anti-TNF-α agents are effective at preventing clinical, endoscopic and surgical POR of CD. The timing of initiating biological therapy after surgery has no significant effect on the rate of POR. The efficacy of infliximab and adalimumab for postoperative recurrence prevention is similar.

A Foley folly: Unintended proximal urethral catheterization and balloon inflation causing urethral injury during suprapubic cystostomy exchange.

Urinary catheter dysfunction is a common emergency department presentation for patients with neurogenic bladders. Many of these patients have cystostomies requiring routine suprapubic catheter exchange. On complication of outpatient catheter replacement, patients are often sent to the emergency department (ED). We describe the case of an 81-year-old male presenting with painless hematuria and blood from the urinary meatus after undergoing routine cystostomy exchange. During Foley replacement, the suprapubic catheter entered the proximal urethra and the balloon was inflated while in the prostatic urethra, leading to urethral injury and cystic clot formation. Emergency physicians should be aware of this rare complication of suprapubic catheter placement.

Diagnosis of Culture-Negative Septic Arthritis with Polymerase Chain Reaction in an Immunosuppressed Patient: A Case Report.

CASE: We present a 23-year-old woman on immunosuppressive therapy with polyarticular, culture-negative septic arthritis. She underwent irrigation and debridement with empiric antibiotic therapy but had recurrence of septic arthritis despite treatment. Polymerase chain reaction testing eventually identified Ureaplasma as the causative organism. She was successfully treated with an extended course of organism-specific antibiotics. CONCLUSION: More patients are being treated with immune modulating therapies. Immunosuppressed patients are at risk for atypical infections and may have different presentations than immunocompetent patients. Newer diagnostic modalities can help identify causative organisms and direct treatment in the case of negative cultures.

Novel use of lip balm under tracheostomy ties to prevent skin irritation in the pediatric patient.

OBJECTIVES: To study the effectiveness of lip balm in reducing skin irritation and preventing pressure induced injury in tracheostomy dependent children. METHODS: The skin of tracheostomy patients presenting to a pediatric otolaryngology clinic over a 12 month period from 2018 to 2019 was assessed and categorized as hyperemic blanchable (abnormal pre-pressure injury), hyperemic non-blanchable, partial thickness skin loss, or full thickness skin loss. Caregivers were instructed to apply lip balm to the skin under soft ties three times per day and with tracheostomy tie changes. Patients were followed prospectively by a tracheostomy care nurse. RESULTS: 24 patients enrolled and reported daily adherence with lip balm use. Median age was 7.3 years (interquartile range, IQR, = 1.3-12.4) with 10 females and 14 males. The majority of patients (n = 20) were identified as having hyperemic blanchable skin. 96% (23/24) of caregivers reported a subjective benefit. 79.2% (95% CI: 57.8%-92.9%) of patients with hyperemic skin (n = 24) demonstrated complete resolution with continued application, and was found to be significant: all patients had skin hyperemia before application, while 20.8% (5/24) continued to have hyperemia after application (P < .001). Infants and ventilation dependent patients demonstrated recovery rates of 88.9% and 75% respectively. Median duration of follow-up was 6.3 months (IQR = 3.4-11.3). There were no documented allergic reactions, accidental decannulations, or skin deterioration in the cohort. CONCLUSIONS: Lip balm appears to be a low cost, hydrophobic, and friction-reducing agent that is potentially useful in preventing at risk pressure injuries in tracheostomy dependent pediatric patients.

Mechanism of Action of the Transobturator Sling for Post-Radical Prostatectomy Incontinence: A Multi-institutional Prospective Study Using Dynamic Magnetic Resonance Imaging.

OBJECTIVE: To compare the length of the membranous (functional) urethra in male patients who underwent the male transobturator sling (TOS) for postradical prostatectomy urinary incontinence (PPI). The TOS is in established use for treatment of PPI; however, the precise mechanism of action is unknown. MATERIALS AND METHODS: This is a prospective case-controlled study on men undergoing male TOS surgery from 2008 to 2014. The comparison arm included patients without incontinence after radical prostatectomy. All participants underwent dynamic magnetic resonance imaging (MRI) at baseline and this was repeated after TOS placement for those who underwent the procedure. Three standardized points were measured using MRI and compared in both groups in addition to clinical measures. RESULTS: Thirty-nine patients were enrolled and 31 patients completed the protocols. The controls (N = 14) had a longer vesicourethral anastomosis to urethra measured at the penile bulb (functional urethral length) distance compared to the pre-TOS group at rest (1.92 cm controls vs 1.27 cm pre-TOS, P = .0018) and at Valsalva (2.13 cm controls vs 1.72 cm pre-TOS, P = .0371). Placement of the sling (N = 17) increased the functional urethral length distance at rest (1.92 cm control vs 1.53 cm post-TOS, P = .09) and at Valsalva (1.94 cm post-TOS vs 2.13 cm control, P = .61), so that the difference was no longer statistically significant. CONCLUSION: We identified that one possible mechanism in improvement in stress urinary incontinence post-TOS placement is the lengthening of the vesicourethral anastomosis to bulbar-urethra distance. This is the first such study utilizing dynamics MRI in post prostatectomy controls, incontinent pre-TOS, and post-TOS to assess and show these findings.

Prevalence of metabolic syndrome and its risk factors in Kerala, South India: Analysis of a community based cross-sectional study.

BACKGROUND: Coronary Artery Disease (CAD) is a leading cause of death and disability in Kerala, India. Metabolic syndrome (MS) is a constellation of established risk factors for CAD. We aimed to estimate the prevalence of MS and evaluate the association between MS and CAD using a community-based sample population. METHODS: A cross-sectional community based survey was conducted in urban and rural areas of Kerala in 2011. We included 5063 individuals for analysis. Age standardized prevalence of MS, associated diagnoses (hypertension, diabetes and hypercholesterolemia) and other potential risk factors were assessed for men and women in both urban and rural locations. Univariate and multivariate logistic regression models were developed to identify participant characteristics that are associated with MS. RESULTS: After standardization for age and adjustment for sex and urban-rural distribution, the prevalence of metabolic syndrome in Kerala was 24%, 29% and 33% for the NCEP ATP III, IDF and AHA/NHLBI Harmonization definitions, respectively. The mean (SD) age of the participants was 51 (14) years, and 60% were women. Women had a higher prevalence of MS than men (28% versus 20% for ATP III, p<0.001). Similarly, participants living in urban areas had higher prevalence of MS than their rural counterparts (26% versus 22%, p<0.001). Elevated body mass index, older age, and female sex were associated with MS in an adjusted multivariate model. The propensity for definite CAD was 1.7 times higher in individuals with MS defined based on ATP III criteria compared to those without MS (Adjusted OR = 1.69; 95% CI: 1.3-2.2, p<0.001). CONCLUSIONS: One of four to one of three adult individuals in Kerala have MS based on different criteria. Higher propensity for CAD in individuals with MS in Kerala calls for urgent steps to prevent and control the burden of metabolic conditions.

Prevalence of coronary artery disease and its risk factors in Kerala, South India: a community-based cross-sectional study.

BACKGROUND: There are no recent data on prevalence of coronary artery disease (CAD) in Indians. The last community based study from Kerala, the most advanced Indian state in epidemiological transition, was in 1993 that reported 1.4% definite CAD prevalence. We studied the prevalence of CAD and its risk factors among adults in Kerala. METHODS: In a community-based cross sectional study, we selected 5167 adults (mean age 51 years, men 40.1%) using a multistage cluster sampling method. Information on socio-demographics, smoking, alcohol use, physical activity, dietary habits and personal history of hypertension, diabetes, and CAD was collected using a structured interview schedule. Anthropometry, blood pressure, electrocardiogram, and biochemical investigations were done using standard protocols. CAD and its risk factors were defined using standard criteria. Comparisons of age adjusted prevalence were done using two tailed proportion tests. RESULTS: The overall age-adjusted prevalence of definite CAD was 3.5%: men 4.8%, women 2.6% (p < 0.001). Prevalence of any CAD was 12.5%: men 9.8%, women 14.3% (p < 0.001). There was no difference in definite CAD between urban and rural population. Physical inactivity was reported by 17.5 and 18% reported family history of CAD. Other CAD risk factors detected in the study were: overweight or obese 59%, abdominal obesity 57%, hypertension 28%, diabetes 15%, high total cholesterol 52% and low level of high density lipoprotein cholesterol 39%. Current smoking was reported only be men (28%). CONCLUSION: The prevalence of definite CAD in Kerala increased nearly three times since 1993 without any difference in urban and rural areas. Most risk factors of CAD were highly prevalent in the state. Both population and individual level approaches are warranted to address the high level of CAD risk factors to reduce the increasing prevalence of CAD in this population.

Evaluation of Novel Ball-Tip Holmium Laser Fiber: Impact on Ureteroscope Performance and Fragmentation Efficiency.

PURPOSE: A novel ball tip (BT) holmium laser fiber has recently been developed, which features a modified rounded tip. The modification is purported to aid in insertion and minimize damage to the ureteroscope working channel. We evaluated this laser fiber with regard to stone comminution, tip degradation, insertional force into the ureteroscope, and impact on ureteroscope deflection. MATERIALS AND METHODS: A 242 µm BT fiber and a standard flat tip (SF) fiber were compared. Four kilojoules was delivered to a BegoStone over a constant surface area using settings of 0.2/50, 0.6/6, 0.8/8, and 1 J/10 Hz. Fiber tip degradation was measured at 1 and 4 kJ. Ureteroscope deflection was measured with the Olympus URF-P5, URF-P6, and URF-V. Insertion force into a 270° angled ureteroscope sheath model was measured. RESULTS: A sample size of five fibers was used for each comminution energy setting. Comminution increased with pulse energy without significant difference between fibers. No significant differences in tip degradation were observed. Both fibers reduced deflection (10°-30°) in all ureteroscopes without significant differences between fibers. Four new fibers paired with new sheath models were used to test insertion force. The BT insertion forces were approximately one-third of the SF. One SF fiber caused significant damage to the sheath and could not be advanced completely. CONCLUSIONS: The BT fiber has comparable comminution, tip degradation, and ureteroscope deflection performance compared with the SF fiber while exhibiting reduced insertion force within an aggressively deflected working sheath. The new tip design is likely protective of the working channel without loss of performance.

Clinical outcomes after ureteroscopic lithotripsy in patients who initially presented with urosepsis: matched pair comparison with elective ureteroscopy.

BACKGROUND AND PURPOSE: The outcomes of ureteroscopy (URS) after urgent decompression and antibiotics for patients who initially present with urosepsis because of obstructive urolithiasis have not been previously evaluated. The aim of this study was to compare the outcomes and complications of URS in patients with a recent history of sepsis with those without sepsis. METHODS: The study included 138 patients who underwent URS for stone removal from January 2004 to September 2011 at a university medical center. A matched-pair analysis was performed using three parameters (age, sex, and race) to compare outcomes and complications between 69 patients who had sepsis vs a matched cohort who did not have sepsis before URS. RESULTS: The study included 138 patients, 88 (64%) females and 50 (36%) males with a median age of 57.5 years (range 18-88 years). Patients with previous sepsis had similar patient characteristics and stone-free rates (81% vs 77%) compared with patients without previous sepsis (P>0.05). Patients with previous sepsis, however, had a significantly higher complications rate (20% vs 7%), longer hospital length of stay (LOS), and longer courses of postoperative antibiotics after URS (P<0.05). Sepsis developed postoperatively in two patients with diabetes (one with and one without previous sepsis), and postoperative fever developed in five patients with previous sepsis. CONCLUSIONS: URS after decompression for urolithiasis-related sepsis has similar success but higher complication rates, greater LOS, and longer course of postoperative antibiotics. This is important in counseling patients who present for definitive URS after urgent decompression for urolithiasis-related sepsis.

Ureteral stenting in laparoscopic colorectal surgery.

BACKGROUND: Few studies have examined the current status of ureteral stent use or the indications for stenting, particularly in laparoscopic colorectal surgery. This study examines current national trends and predictors of ureteral stenting in patients undergoing major colorectal operations and the subsequent effects on perioperative outcomes. METHODS: The 2005-2011 National Surgical Quality Improvement participant user files were used to identify patients undergoing laparoscopic segmental colectomy, low anterior resection, or proctectomy. Trends in stent use were assessed across procedure types. To estimate the predictors of stent utilization, a forward-stepwise logistic regression model was used. A 3:1 nearest neighbor propensity match with subsequent multivariable adjustment was then used to estimate the impact of stents. RESULTS: A total of 42,311 cases were identified, of which 1795 (4.2%) underwent ureteral stent placement. Predictors of stent utilization included diverticular disease, need for radical resection (versus segmental colectomy), recent radiotherapy, and more recent calendar year. After adjustment, ureteral stenting appeared to be associated with a small increase in median operative time (44 min) and a trivial increase in length of stay (5.4%, P<0.001). However, there were no significant differences in morbidity or mortality. CONCLUSIONS: We describe the clinical predictors of ureteral stent usage in this patient population and report that while stenting adds to operative time, it is not associated with significantly increased morbidity or mortality after adjusting for diagnosis and comorbidities. Focused institutional studies are necessary in the future to address the utility of ureteral stents in the identification and possible prevention of iatrogenic injury.

Emergent ureteric stent vs percutaneous nephrostomy for obstructive urolithiasis with sepsis: patterns of use and outcomes from a 15-year experience.

OBJECTIVES: To characterize the use of emergent JJ ureteric stent placement and percutaneous nephrostomy (PCN) for patients with obstructive urolithiasis with sepsis, and to determine whether outcomes differ between the two treatment methods. PATIENTS AND METHODS: A total of 130 patients with obstructive urolithiasis and systemic inflammatory response syndrome criteria were identified retrospectively from a single health system database from 1995 to 2011. Primary outcomes included stone-related and clinical variables which predicted the use of each treatment method. Secondary outcomes included the length of hospital stay, risk of intensive care unit (ICU) admission, and surgical approach used for definitive stone management. RESULTS: The overall rate of failed procedures was 2.3% (3/130), with one in-hospital death (0.8%). Patients treated with PCN had larger stones (10 vs 7 mm, P = 0.031), and were more acutely ill (acute physiology, age, chronic health evaluation [APACHE] II scores of 15 vs 11, P = 0.036) than those treated with JJ stent placement. Patients treated with PCN were more likely to require ICU admission (odds ratio: 3.23, 95% confidence interval [CI]: 1.24-8.41, P = 0.016), and demonstrated longer length of hospital stay (ß: 0.47, 95% CI: 0.20-0.74, P = 0.001), even when adjusting for age, APACHE II score, and Charlson Comorbidity Index score. After resolution of sepsis, patients treated with PCN were more likely to be treated definitively with a percutaneous approach, while patients treated with JJ stent placement were more likely to be treated ureteroscopically. CONCLUSIONS: Both JJ stent placement and PCN drainage appear effective. Patients with larger stones and who are more acutely ill are more likely to be treated with PCN. Additional randomized clinical trials of adequate power are warranted to define the optimum management of these often complex cases.

Obesity triples the radiation dose of stone protocol computerized tomography.

PURPOSE: Patients with recurrent nephrolithiasis are often evaluated and followed with computerized tomography. Obesity is a risk factor for nephrolithiasis. We evaluated the radiation dose of computerized tomography in obese and nonobese adults. MATERIALS AND METHODS: We scanned a validated, anthropomorphic male phantom according to our institutional renal stone evaluation protocol. The obese model consisted of the phantom wrapped in 2 Custom Fat Layers (CIRS, Norfolk, Virginia), which have been verified to have the same radiographic tissue density as fat. High sensitivity metal oxide semiconductor field effect transistor dosimeters were placed at 20 organ locations in the phantoms to measure organ specific radiation doses. The nonobese and obese models have an approximate body mass index of 24 and 30 kg/m(2), respectively. Three runs of renal stone protocol computerized tomography were performed on each phantom under automatic tube current modulation. Organ specific absorbed doses were measured and effective doses were calculated. RESULTS: The bone marrow of each model received the highest dose and the skin received the second highest dose. The mean ± SD effective dose for the nonobese and obese models was 3.04 ± 0.34 and 10.22 ± 0.50 mSv, respectively (p <0.0001). CONCLUSIONS: The effective dose of stone protocol computerized tomography in obese patients is more than threefold higher than the dose in nonobese patients using automatic tube current modulation. The implication of this finding extends beyond the urological stone population and adds to our understanding of radiation exposure from medical imaging.

Increasing dwell time of mitomycin C in the upper tract with a reverse thermosensitive polymer.

UNLABELLED: Abstract Background and Purpose: Topical chemotherapy for urothelial cancer is dependent on adequate contact time of the chemotherapeutic agent with the urothelium. To date, there has not been a reliable method of maintaining this contact for renal or ureteral urothelial carcinoma. We evaluated the safety and feasibility of using a reverse thermosensitive polymer to improve dwell times of mitomycin C (MMC) in the upper tract. MATERIALS AND METHODS: Using a porcine model, four animals were treated ureteroscopically with both upper urinary tracts receiving MMC mixed with iodinated contrast. One additional animal received MMC percutaneously. The treatment side had ureteral outflow blocked with a reverse thermosensitive polymer plug. MMC dwell time was monitored fluoroscopically and intrarenal pressures measured. Two animals were euthanized immediately, and three animals were euthanized 5 days afterward. RESULTS: In control kidneys, drainage occurred at a mean of 5.3±0.58 minutes. Intrarenal pressures stayed fairly stable: 9.7±14.0 cm H20. In treatment kidneys, dwell time was extended to 60 minutes, when the polymer was washed out. Intrarenal pressures in the treatment kidneys peaked at 75.0±14.7 cm H20 and reached steady state at 60 cm H20. Pressures normalized after washout of the polymer with cool saline. Average washout time was 11.8±9.6 minutes. No histopathologic differences were seen between the control and treatment kidneys, or with immediate compared with delayed euthanasia. CONCLUSIONS: A reverse thermosensitive polymer can retain MMC in the upper urinary tract and appears to be safe from our examination of intrarenal pressures and histopathology. This technique may improve the efficacy of topical chemotherapy in the management of upper tract urothelial carcinoma.

In-vitro assessment of a new portable ballistic lithotripter with percutaneous and ureteroscopic models.

BACKGROUND AND PURPOSE: The EMS Swiss LithoBreaker is a new, portable, electrokinetic lithotripter. We compared its tip velocity and displacement characteristics with a handheld, pneumatic lithotripter LMA StoneBreaker.™ We also evaluated fragmentation efficiency using in vitro models of percutaneous and ureteroscopic stone fragmentation. MATERIALS AND METHODS: Displacement and velocity profiles were measured for 1-mm and 2-mm probes using a laser beam aimed at a photo detector. For the percutaneous model, 2-mm probes fragmented 10-mm spherical BegoStone phantoms until the fragments passed through a 4-mm mesh sieve. The ureteroscopic model used 1-mm probes and compared the pneumatic and electrokinetic devices to a 200-µm holmium laser fiber. Cylindrical (4-mm diameter, 4-mm length) BegoStone phantoms were placed into silicone tubing to simulate the ureter; fragmented stones passed through a narrowing in the tubing. RESULTS: For both 1-mm and 2-mm probes, the electrokinetic device had significantly higher tip displacement and slower tip velocity, P<0.01. In the percutaneous model, the electrokinetic device needed an average of 484 impulses over 430 seconds to fragment one BegoStone, while the pneumatic device needed 29 impulses over 122 seconds to fragment one stone. Both clearance times and number of impulses needed for percutaneous stone clearance were significantly different at P<0.01. Ureteroscopically, the mean clearance time was 97 seconds for the electrokinetic lithotripter, 145 seconds for the pneumatic lithotripter, and 304 seconds for the laser. Comparing the pneumatic device with the electrokinetic device ureteroscopically, there was no significant difference in clearance time, P=0.55. Both the pneumatic and electrokinetic lithotripters, however, demonstrated decreased clearance times compared with the laser, P=0.027. CONCLUSIONS: The portable electrokinetic lithotripter may be better suited for ureteroscopy instead of percutaneous nephrolithotomy. It appears to be comparable to the portable pneumatic device in the ureter. Further clinical studies are needed to confirm these findings in vivo.