Extracorporeal Shock Wave Therapy: Current Perspectives and Future Directions.

PURPOSE OF REVIEW: Since its introduction, extracorporeal shock wave lithotripsy (ESWL) has undergone a variety of changes; however, it remains one of the most utilized treatment modalities for urolithiasis. The goal of this review is to provide the practicing urologist an update on contemporary trends, new technologies, and related controversies in utilizing ESWL for stone treatment. RECENT FINDINGS: ESWL use has come under scrutiny with a shift in focus to cost-effectiveness and healthcare outcomes. Fortunately, advances in lithotripter technology have spawned several generations of devices that strive to improve stone-free rates and decrease complications. Most of all, a focus on patient selection criteria has helped improve procedural success. Years of experience utilizing ESWL for stone treatment have helped urologists better optimize its use and minimize complications. Improvements in technique along with more stringent patient and stone selection have helped ESWL remain a mainstay in the treatment of stone disease.

Factors Associated with Compliance in Submitting 24-Hour Urine Collections in an Underserved Community.

PURPOSE: Patients living in underserved areas do regularly express an interest in stone prevention; however, factors limiting participation, aside from obvious cost considerations, are largely unknown. To better understand factors associated with compliance with submitting 24-hour urine collections, we reviewed our patient experience at the kidney stone clinic at a hospital that provides care for an underserved urban community. MATERIALS AND METHODS: A retrospective chart review of patients treated for kidney and/or ureteral stones between August 2014 and May 2016 was performed. Patient demographics, medical characteristics, stone factors, and compliance data were compiled into our data set. Patients were divided into two groups: those who did and did not submit the requested initial 24-hour urine collection. Analysis of factors related to compliance was performed using univariate analysis and multivariate logistic regression. RESULTS: A total of 193 patients met inclusion criteria for our study, 42.5% (82/193) of whom submitted 24-hour urine samples. Of the 82 collections submitted, 34.1% (28/82) were considered inadequate by creatinine level. A second urine collection within 6 months was obtained in 14.0% (27/193) of patients. Univariate analysis demonstrated that African American (AA) patients were less likely to submit an initial 24-hour urine collection than Caucasian patients (collected: 30.9% vs 51.8%; p < 0.05, respectively). Patients with a family history of kidney stones were more likely to submit an initial 24-hour urine collection than patients without a family history of kidney stones (61.1% vs 38.2%, p < 0.02, respectively). On multivariate analysis, both factors remained significant predictors of compliance with submitting a 24-hour urine collection. CONCLUSIONS: In our underserved patient population, AA patients were half as likely to submit a 24-hour urine collection than Caucasian patients, whereas patients with a positive family history of stones were more than twice as likely to submit than patients with no family history.

Evaluation of heme peripheral group interactions in extremely low-dielectric constant media and their contributions to the heme reduction potential.

In this study, we measured the contributions of the ionization of the heme propionates to the reduction potentials of heme b and heme a (bis)N-methylimidazole complexes in various low-dielectric constant conditions. Additionally, we measured the effects of H-bond to the heme a formyl group on the reduction potential of the heme. The performed electrochemical measurements show that ionization of the heme propionates lead to the largest redox change in dichloromethane with no electrolyte. The measured reduction potential changes for heme b and heme a were -55 and -47 mV (±10 mV) per ionized propionate, respectively. For heme a, the study demonstrates how the dielectric constant of the medium is important in the magnification of the ΔpKa upon redox-linked ionization of the heme propionates and their roles in the proton pump of cytochrome c oxidase.