Temperature-dependent differences between readily releasable and reserve pool vesicles in chromaffin cells

AbstractStatistical differences between amperometric traces recorded from chromaffin cells using K+ and Ba2+ secretagogues support the assertion that readily releasable pool (RRP) and reserve pool (RP) vesicles can be probed with pool-specific secretagogues. Release from the RRP was evoked by K+ while release from the RP was evoked by Ba2+. Similar temperature-dependent changes in spike area and half-width for both pools suggest that the content of RRP and RP vesicles is similar and packaged in the same way. Differences between the vesicle pools were revealed in the temperature dependence of spike frequency. While the burst spike frequency of the RRP, which is comprised of pre-docked and primed vesicles, increased 2.8% per °C, the RP spike frequency increased 12% per °C. This difference is attributed to a temperature-dependent mobilization of the RP. Furthermore, the RP exhibited more foot events at room temperature than the RRP but this difference was not apparent at 37 °C. This trend suggests that RP vesicle membranes have a compromised surface tension compared to RRP vesicles. Collectively, the changes of release characteristics with temperature reveal distinctions between the RRP and the RP

Intraoperative Cystoscopic Evaluation of Ureteral Patency: A Randomized Controlled Trial.

OBJECTIVE: To compare different modalities to aid in the evaluation of intraoperative ureteral patency on cystoscopy in the postindigo carmine era. METHODS: In a randomized controlled trial, participants undergoing pelvic surgery were randomized into one of four groups: saline distention (control), 10% dextrose distention, oral phenazopyridine, or intravenous sodium fluorescein. Our primary outcome was visibility of the ureteral jets. Secondary outcomes included surgeon satisfaction; adverse reactions including allergies, urinary tract infections, urinary retention, cystoscopy times, and ureteral obstruction; and delayed diagnosis. Participants were followed for 6 weeks. A sample size of 176 participants was planned to demonstrate a 30% difference in the visibility scale. All analyses were performed in an intention-to-treat fashion. RESULTS: From February 25, 2015, through August 2015, 176 participants were enrolled; 174 completed the trial, and two did not undergo intervention. Forty-four participants were included in the phenazopyridine, dextrose, saline, and sodium fluorescein groups. Sodium fluorescein and 10% dextrose resulted in significantly improved visibility and satisfaction when compared with the control group (P CONCLUSION: Compared with the control, 10% dextrose and sodium fluorescein resulted in improved visibility and provided significantly more satisfaction in the evaluation for ureteral patency with no considerable increase in operative time or morbidity. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT02476448