Continental Scale Hydrostratigraphy: Basin-Scale Testing of Alternative Data-Driven Approaches.

Integrated hydrological modeling is an effective method for understanding interactions between parts of the hydrologic cycle, quantifying water resources, and furthering knowledge of hydrologic processes. However, these models are dependent on robust and accurate datasets that physically represent spatial characteristics as model inputs. This study evaluates multiple data-driven approaches for estimating hydraulic conductivity and subsurface properties at the continental-scale, constructed from existing subsurface dataset components. Each subsurface configuration represents upper (unconfined) hydrogeology, lower (confined) hydrogeology, and the presence of a vertical flow barrier. Configurations are tested in two large-scale U.S. watersheds using an integrated model. Model results are compared to observed streamflow and steady state water table depth (WTD). We provide model results for a range of configurations and show that both WTD and surface water partitioning are important indicators of performance. We also show that geology data source, total subsurface depth, anisotropy, and inclusion of a vertical flow barrier are the most important considerations for subsurface configurations. While a range of configurations proved viable, we provide a recommended Selected National Configuration 1 km resolution subsurface dataset for use in distributed large-and continental-scale hydrologic modeling.

Cutaneous angiosarcoma presenting as bilateral periorbital edema.

A 66-year-old man presented with chronic bilateral periorbital edema with associated yellowish hue, scattered violaceous smooth macules and contracture of the forehead. He had undergone dental surgery 3 months prior to symptom onset. Laboratory workup for common causes of eyelid edema was unremarkable and MRI of the orbits was unrevealing. The patient did not respond to oral corticosteroids or antibiotics. Punch biopsies were obtained which revealed atypical lymphatic endothelial cells consistent with a diagnosis of cutaneous angiosarcoma.The patient was deemed not to be a surgical candidate and underwent 3 cycles of immunotherapy with limited response. He declined further treatment and transitioned to hospice care. Although cutaneous angiosarcoma uncommonly involves the periorbital region, it should be considered in the differential diagnosis of eyelid edema as early recognition and treatment are critical to prevent rapid intradermal spread and metastases.

Frailty Severity and Hospitalization After Dialysis Initiation.

BACKGROUND: Frailty is associated with hospitalization and mortality among dialysis patients. To now, few studies have considered the degree of frailty as a predictor of hospitalization. OBJECTIVE: We evaluated whether frailty severity was associated with hospitalization after dialysis initiation. DESIGN: Retrolective cohort study. SETTING: Nova Scotia, Canada. PATIENTS: Consecutive adult, chronic dialysis patients who initiated dialysis from January 1, 2009 to June 30, 2014, (last follow-up June, 2015). METHODS: Frailty Severity, as determined by the 7-point Clinical Frailty Scale (CFS, ranging from 1 = very fit to 7 = severely frail), was measured at dialysis initiation and treated as continuous and in categories (CFS scores of 1-3, 4/5, and 6/7). Hospitalization was characterized by cumulative time admitted to hospital (proportion of days admitted/time at risk) and by the joint risk of hospitalization and death. Time at risk included time in hospital after dialysis initiation and patients were followed until transplantation or death. RESULTS: Of 647 patients (mean age: 62 ± 15), 564 (87%) had CFS scores. The mean CFS score was 4 ("corresponding to "vulnerable") ± 2 ("well" to "moderately frail"). In an adjusted negative binomial regression model, moderate-severely frail patients (CFS 6/7) had a >2-fold increased risk of cumulative time admitted to hospital compared to the lowest CFS category (IRR = 2.18, 95% confidence interval [CI] = 1.31-3.63). In the joint model, moderate-severely frail patients had a 61% increase in the relative hazard for hospitalization (hazard ratio [HR] = 1.61, 95% CI = 1.29-2.02) and a 93% increase in the relative hazard for death compared to the lowest CFS category (HR = 1.93, 95% CI = 1.16-3.22). LIMITATIONS: Potential unknown confounders may have affected the association between frailty severity and hospitalization given observational study design. The CFS is subjective and different clinicians may grade frailty severity differently or misclassify patients on the basis of limited availability. CONCLUSIONS: Among incident dialysis patients, a higher frailty severity as defined by the CFS is associated with both an increased risk of cumulative time admitted to hospital and joint risk of hospitalization and death.

CONTEXTE: La fragilité est associée à davantage d'hospitalisations et de mortalité chez les patients qui suivent des traitements de dialyze. À l'heure actuelle, peu d'études se sont penchées sur le degré de fragilité comme facteur prédictif d'hospitalization. OBJECTIFS: Nous avons évalué l'existence d'un lien entre la gravité de la fragilité et le risque d'hospitalization après l'amorce d'un traitement de dialyze. TYPE D'ÉTUDE: Étude de cohorte rétrospective. CADRE: Nouvelle-Écosse, Canada. SUJETS: L'étude porte sur des patients adultes consécutifs sous dialyze chronique et ayant entrepris leur traitement entre le 1er janvier 2009 et le 30 juin 2014 (dernier suivi en juin 2015). MÉTHODOLOGIE: L'échelle CFS (Clinical Frailty Scale) en 7 points (1 = très bonne forme physique; 7= gravement fragile) a été employée pour déterminer le niveau de gravité de la fragilité. Cette dernière a été évaluée à l'amorce de la dialyze et traitée en tant que mesure continue et selon trois niveaux d'atteinte (scores CFS de 1-3, de 4-5 et de 6-7). L'hospitalization a été caractérisée par la durée cumulative des hospitalisations (proportion de jours d'hospitalization/l'intervalle de risque) et par un risque conjoint d'hospitalization et de décès. L'intervalle de risque comprend le temps passé à l'hôpital depuis le début du traitement. Les patients ont été suivis jusqu'à la transplantation ou jusqu'au décès. RÉSULTATS: Parmi les 647 patients admissibles (âge moyen: 62 ans ± 15), 564 patients (87 %) disposaient d'un score CFS. Le score CFS moyen était de 4 (correspondant à « apparence de vulnérabilité ¼) ± 2 (« bonne forme physique ¼ à « modérément fragile ¼). Dans un modèle corrigé de régression binomiale négative, les patients jugés modérément à gravement fragiles (CFS 6/7) présentaient un risque cumulatif plus de 2 fois plus élevé d'être hospitalisés comparativement aux patients du groupe avec le score CFS le plus faible (RTI: 2,18; IC 95 %: 1,31 à 3,63). Dans le modèle conjoint, les patients jugés modérément à gravement fragiles ont présenté une augmentation de 61 % du risque relatif d'hospitalization (RR:1,61; IC 95 %: 1,29 à 2,02) et une augmentation de 93 % du risque relatif de décès comparativement aux patients avec le score CFS le plus faible (RR: 1,93; IC 95 %: 1,16 à 3,22). LIMITES: La méthodologie de l'étude (observationnelle) laisse supposer que de possibles facteurs confusionnels inconnus pourraient avoir eu une incidence sur le lien entre les hospitalisations et la gravité de la fragilité. Le score CFS est une mesure subjective. Il est possible que les cliniciens évaluent différemment la gravité de la fragilité ou classent les patients de façon erronée en raison d'une disponibilité limitée. CONCLUSION: Chez les patients dialysés, une plus grande fragilité, telle que définie par le score CFS, a été associée à la fois à un risque accru d'être hospitalisé sur une plus longue durée cumulative et à un risque conjoint d'hospitalization et de décès.

Modeling the Effects of Calcium Overload on Mitochondrial Ultrastructural Remodeling.

Mitochondrial cristae are dynamic invaginations of the inner membrane and play a key role in its metabolic capacity to produce ATP. Structural alterations caused by either genetic abnormalities or detrimental environmental factors impede mitochondrial metabolic fluxes and lead to a decrease in their ability to meet metabolic energy requirements. While some of the key proteins associated with mitochondrial cristae are known, very little is known about how the inner membrane dynamics are involved in energy metabolism. In this study, we present a computational strategy to understand how cristae are formed using a phase-based separation approach of both the inner membrane space and matrix space, which are explicitly modeled using the Cahn-Hilliard equation. We show that cristae are formed as a consequence of minimizing an energy function associated with phase interactions which are subject to geometric boundary constraints. We then extended the model to explore how the presence of calcium phosphate granules, entities that form in calcium overload conditions, exert a devastating inner membrane remodeling response that reduces the capacity for mitochondria to produce ATP. This modeling approach can be extended to include arbitrary geometrical constraints, the spatial heterogeneity of enzymes, and electrostatic effects to mechanize the impact of ultrastructural changes on energy metabolism.

The very low number of calcium-induced permeability transition pores in the single mitochondrion.

Mitochondrial permeability transition (PT) is a phenomenon of stress-induced increase in nonspecific permeability of the mitochondrial inner membrane that leads to disruption of oxidative phosphorylation and cell death. Quantitative measurement of the membrane permeability increase during PT is critically important for understanding the PT's impact on mitochondrial function. The elementary unit of PT is a PT pore (PTP), a single channel presumably formed by either ATP synthase or adenine nucleotide translocator (ANT). It is not known how many channels are open in a single mitochondrion during PT, which makes it difficult to quantitatively estimate the overall degree of membrane permeability. Here, we used wide-field microscopy to record mitochondrial swelling and quantitatively measure rates of single-mitochondrion volume increase during PT-induced high-amplitude swelling. PT was quantified by calculating the rates of water flux responsible for measured volume changes. The total water flux through the mitochondrial membrane of a single mitochondrion during PT was in the range of (2.5 ± 0.4) × 10-17 kg/s for swelling in 2 mM Ca2+ and (1.1 ± 0.2) × 10-17 kg/s for swelling in 200 µM Ca2+. Under these experimental conditions, a single PTP channel with ionic conductance of 1.5 nS could allow passage of water at the rate of 0.65 × 10-17 kg/s. Thus, we estimate the integral ionic conductance of the whole mitochondrion during PT to be 5.9 ± 0.9 nS for 2 mM concentration of Ca2+ and 2.6 ± 0.4 nS for 200 µM of Ca2+. The number of PTPs per mitochondrion ranged from one to nine. Due to the uncertainties in PTP structure and model parameters, PTP count results may be slightly underestimated. However, taking into account that each mitochondrion has ∼15,000 copies of ATP synthases and ANTs, our data imply that PTP activation is a rare event that occurs only in a small subpopulation of these proteins.

Should donors who have used marijuana be considered candidates for living kidney donation?

BACKGROUND: The use of marijuana in the USA has been steadily increasing over the last 10 years. This study is the first to investigate the effect of marijuana use by live kidney donors upon outcomes in both donors and recipients. METHODS: Living kidney donor transplants performed between January 2000 and May 2016 in a single academic institution were retrospectively reviewed. Donor and recipient groups were each divided into two groups by donor marijuana usage. Outcomes in donor and recipient groups were compared using t-test, Chi-square and mixed linear analysis (P < 0.05 considered significant). RESULTS: This was 294 living renal donor medical records were reviewed including 31 marijuana-using donors (MUD) and 263 non-MUDs (NMUD). It was 230 living kidney recipient records were reviewed including 27 marijuana kidney recipients (MKRs) and 203 non-MKRs (NMKR). There was no difference in donor or recipient perioperative characteristics or postoperative outcomes based upon donor marijuana use (P > 0.05 for all comparisons). There was no difference in renal function between NMUD and MUD groups and no long-term difference in kidney allograft function between NMKR and MKR groups. CONCLUSIONS: Considering individuals with a history of marijuana use for living kidney donation could increase the donor pool and yield acceptable outcomes.

Impact of a Wireless System Upon Verbal Communication in a Simulated Robotic Operating Theater.

OBJECTIVE: To compare the efficacy of communication via the standard Da Vinci Si speaker system with a wireless, hands-free audio system in a prospective blinded study. METHODS: Nine hundred and sixty surgical phrases were spoken in a simulated robotic operating room (OR), including 480 phrases expressed via the Da Vinci Si speakers and 480 phrases expressed through a wireless, hands-free system. Using a dual console robotic system, communication was evaluated. Wireless headsets were given to the console and assistant robotic console surgeons, bedside assistant, anesthesiologist, and circulating nurse. An accurate response was defined as hearing the phrase correctly and transcribing it on a data sheet. The primary outcome was the number of correct phrases recorded during the study and secondary outcomes included subjective clarity and effectiveness of communication reported using a Likert scale. RESULTS: Overall, the wireless, hands-free system increased the accuracy of communication (390/480 [81.3%]) compared to the conventional robotic system (310/480 [64.4%]; P <.001). The bedside assistant, anesthesiologist, and circulating nurse had significantly fewer correct phrases recorded than the assistant robotic console surgeon when using the robotic speakers (P <.05 for all). In contrast, there were no significant differences in the number of correct phrases recorded between different positions when using the wireless system. Subjectively, the wireless system resulted in improved clarity and effectiveness of communication (P = .021; P <.001, respectively). CONCLUSION: Robotic operating systems have intrinsic barriers to effective communication between the surgeon and the rest of the operating room team. Improved communication could reduce surgical errors and improve patient safety.

Efficacy of antegrade and retrograde warm saline pyeloperfusion during renal cryoablation for ureteral preservation.

OBJECTIVE: Cryoablation of renal tumors adjacent to the ureter or pelvicalyceal system carries risks for thermal injury of the collecting system. Although cold antegrade perfusion has been described for radiofrequency ablation, warm saline perfusion for renal cryoablation has not been well-characterized. The purpose of this study was to determine the safety and feasibility of antegrade and retrograde warm saline perfusions during percutaneous renal cryoablation. MATERIAL AND METHODS: A retrospective review was performed on 136 patients treated with percutaneous renal cryoablation at a single academic institution between 2009 and 2015. Six patients undergoing antegrade (n=3) or retrograde (n=3) warm saline perfusion for protection of the collecting system were identified. Warm saline was perfused through a 4 French nephrostomy tube in the antegrade technique and through a 6 French end-hole catheter in the retrograde technique. Outcome measures were tumor recurrence rates, success of urothelial preservation, hospital stay, blood loss and procedural time. RESULTS: Four tumors were in the lower pole and two tumors in the middle pole. The mean distance from tumor to ureter was 6.8 mm (0.8-11.5 mm) and no patient developed ureteral stricture. There was no tumor recurrence at a median follow-up of 37.3 months (7-65). The median procedural time was 3 hours and 13 minutes. One patient in each group developed minor complications (Clavien I and II) and there were no major complications. CONCLUSION: This study demonstrates the feasibility of antegrade and retrograde warm saline perfusion for ureteral preservation during cryoablation, without compromising oncologic outcomes.

Conventional vs Computer-Assisted Stereoscopic Ultrasound Needle Guidance for Renal Access: A Randomized Crossover Bench-Top Trial.

PURPOSE: Ultrasound (US) guidance during renal access and mass biopsy reduces radiation exposure, but can be technically challenging. A needle guidance system might simplify these procedures. The purpose of this randomized crossover trial was to compare conventional and computer-assisted US needle guidance systems for renal access and mass biopsy. MATERIALS AND METHODS: Seventy-one subjects were randomized to perform renal access or mass biopsy on a phantom using conventional and computer-assisted US guidance in a crossover study design. The primary outcome was success rate including subgroup analysis by experience level. Secondary outcomes included total procedure time, time to hit target, number of course corrections, and total punctures. In addition, subjective preferences of participants were also collected. RESULTS: Procedure success rate was higher with the computer-assisted US than with conventional US for both novice (98.0% (48/49) vs 81.6% (40/49); p < 0.001) and experienced US users (100% (22/22) vs 81.8% (18/22); p < 0.001). Computer-assisted US significantly shortened the total procedure time (94.0 seconds vs 192.9 seconds; p ≤ 0.001), time required to hit the target (62.5 seconds vs 121.6 seconds; p ≤ 0.001), and the number of course corrections (0.56 vs 2.89; p < 0.001) compared with conventional US. Computer-assisted US did not significantly reduce the number of needle punctures (1.75 vs 2.39; p = 0.132). Seventy-three percent of subjects preferred the computer-assisted US system. CONCLUSION: A computer-assisted needle guidance system increases effective US targeting for renal access and mass biopsy for novice and experienced users.

Elevated Renal Pelvic Pressures during Percutaneous Nephrolithotomy Risk Higher Postoperative Pain and Longer Hospital Stay.

PURPOSE: Renal pelvic pressure may vary during percutaneous nephrolithotomy. We sought to determine the relationship of postoperative pain to endoscope caliber, renal pelvic pressure and hospital stay. MATERIALS AND METHODS: We reviewed the records of 20 percutaneous nephrolithotomies done under ureteroscopic guidance with renal pelvic pressure monitoring. The ureteroscope working channel was connected to a pressure transducer and used to determine renal pelvic pressure at baseline, when irrigating with a 26Fr rigid nephroscope and a 16Fr flexible nephroscope, and during suction. Patient demographics, operative characteristics, Likert pain scores and length of hospital stay were compared as stratified by average renal pelvic pressure. The Mann-Whitney U and Fisher exact tests were used with p <0.05 considered significant. RESULTS: A total of 220 measurements were recorded in 20 patients undergoing single access percutaneous nephrolithotomy. Mean patient age was 55.2 years (range 20 to 77) and mean body mass index was 32.4 kg/m2 (range 18 to 53.3). Rigid nephroscopy resulted in significantly higher average renal pelvic pressure than flexible nephroscopy (30.3 vs 12.9 mm Hg, p = 0.007). Average renal pelvic pressure was 30 mm Hg or greater in 7 patients (35%) undergoing rigid nephroscopy and in none (0%) undergoing flexible nephroscopy (p <0.01). Patients exposed to an average renal pelvic pressure of 30 mm Hg or greater during rigid nephroscopy had significantly higher average pain scores (p = 0.004) and longer hospital stays (p = 0.04) than patients with renal pelvic pressure less than 30 mm Hg. Average renal pelvic pressure 30 mm Hg or greater during rigid nephroscopy was also associated with a longer skin to calyx distance (105.5 vs 79.7 mm, p = 0.03). CONCLUSIONS: Knowledge of the factors that influence renal pelvic pressure and methods to control pressure extremes may improve patient outcomes during percutaneous nephrolithotomy.

Real-World Use and Self-Reported Health Outcomes of a Patient-Designed Do-it-Yourself Mobile Technology System for Diabetes: Lessons for Mobile Health.

BACKGROUND: The aim of this study is to compare demographic/disease characteristics of users versus nonusers of a do-it-yourself (DIY) mobile technology system for diabetes (Nightscout), to describe its uses and personalization, and to evaluate associated changes in health behaviors and outcomes. METHODS: A cross-sectional, household-level online survey was used. Of 1268 household respondents who were members of the CGM in the Cloud Facebook group, there were 1157 individuals with diabetes who provided information about Nightscout use. RESULTS: The majority of individuals with diabetes in the household sample were 6-12 years old (followed by 18 years and above, and 13-17 years), non-Hispanic whites (90.2%), with type 1 diabetes (99.4%). The majority used an insulin pump (85.6%) and CGM (97.0%) and had private health insurance (83.8%). Nightscout use was more prevalent among children compared with adolescents and adults. Children used Nightscout for nighttime, school, sporting events, and travel; adults used it for nighttime, work, travel, and sporting events. Whereas the majority of adults viewed their own data without assistance from others, among pediatric users, a median of three individuals (range: 0-8) viewed Nightscout, with a median of three devices per viewer (range: 0-7). Individuals reported that after Nightscout adoption, they checked blood glucose values with a meter less often; bolused more frequently; gave more boluses without checking first with a blood glucose meter; and experienced significant improvements in HbA1c and quality of life. CONCLUSIONS: The Nightscout Project is a patient-driven mobile technology for health and may have beneficial effects on glycemic control and quality of life.