Physiological and pharmacological characterization of a molluscan neuronal efflux transporter; evidence for age-related transporter impairment.

Plasma membrane efflux transporters play crucial roles in the removal and release of both harmful and beneficial substances from the interior of cells and tissue types in virtually every extant species. They contribute to the clearance of a broad spectrum of exogenous and endogenous toxicants and harmful metabolites, including the reactive lipid aldehyde byproducts of lipid peroxidation that are a hallmark of cellular ageing. Here, we tested whether declining transporter functionality may contribute to functional decline in a snail model of neuronal ageing. Through measuring the removal of 5(6)-carboxyfluorescein, a known substrate for membrane efflux transporters, we provide, for the first time, physiological evidence for the existence of probenecid-, MK571- and glutathione-sensitive efflux transporters in (gastropod) neurons and demonstrate that their functionality declines with age. Our data support the idea that waning cellular detoxification capacity might be a significant factor in the escalation of (lipo-)toxicity observed in neuronal ageing.

Proximal Row Carpectomy Modifications for Capitate Arthritis: A Systematic Review.

Introduction Proximal row carpectomy (PRC) is a motion-sparing procedure for radiocarpal arthritis with reliable results. Traditionally, proximal capitate arthritis is a contraindication to PRC; however, PRC with modifications are proposed to circumvent this contraindication. PRC modifications can be broadly grouped into capitate resurfacing (CR) and capsular interposition (CI) procedures which could expand PRC indications. Our primary question was to characterize the outcomes achievable with various PRC modifications. Our secondary question was to determine which PRC modification was the optimal procedure when capitate arthritis was present. Methods A systematic review was conducted to examine the outcomes of modified PRC procedures. Independent reviewers appraised multiple databases for PRC studies with modifications for capitate arthritis in adult patients (age >18 years) with a minimum of three cases and extractable outcomes. Modified PRC procedures included capsular/allograft interposition, resurfacing capitate pyrocarbon implants, and osteochondral grafting. Pertinent outcomes included patient demographics, range-of-motion, grip strength, patient-reported outcomes, and complications, including salvage rates. Results Overall, 18 studies met the inclusion criteria-10 studies ( n = 147) on CI and 8 studies on CR ( n = 136). PRC with CI had the greatest flexion-extension arc and grip strength. Complications were marginally higher in the CR group (4%), while the CI group had a higher conversion to total wrist arthrodesis (10%). Conclusion Techniques to address capitate arthritis center around resurfacing or soft tissue interposition. PRC modifications with CI produces better range-of-motion and grip strength but higher conversion to total wrist arthrodesis. Higher conversion rates may be attributable to longer follow-up periods in studies examining CI compared with CR. Level of Evidence This is a Level III study.

Feasibility of three-dimensional facial imaging and printing for producing customised nasal masks for continuous positive airway pressure.

RATIONALE: Delivery of continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnoea in children and adults. Treatment adherence is a major challenge, as many patients find the CPAP mask uncomfortable. The study aim was to demonstrate the feasibility of delivered CPAP through customised nasal masks by assessing mask leak and comfort of customised masks compared to commercially available CPAP masks. METHODS: Six healthy adult volunteers participated in a crossover study including commercial masks in three different sizes (petite, small/medium and large) from the same supplier and a customised mask fabricated for each subject using three-dimensional facial scanning and modern additive manufacturing processes. Mask leak and comfort were assessed with varying CPAP levels and mask tightness. Leak was measured in real time using an inline low-resistance Pitot tube flow sensor, and each mask was ranked for comfort by the subjects. RESULTS: Mask leak rates varied directly with CPAP level and inversely with mask tightness. When ranked for comfort, three subjects favoured the customised mask, while three favoured a commercial mask. The petite mask yielded the highest mask leaks and was ranked least comfortable by all subjects. Relative mask leaks and comfort rankings for the other commercial and customised masks varied between individuals. Mask leak was comparable when comparing the customised masks with the highest ranked commercial masks. CONCLUSION: Customised masks successfully delivered target CPAP settings in all six subjects, demonstrating the feasibility of this approach.

Positioning Performance of Power and Manual Drivers in Posterior Spinal Fusion Procedures.

This work presents an analysis and comparison of the efficacy of two methods for pedicle screw placement during posterior spinal fusion surgery. A total of 100 screws (64 manual and 36 power driven), all placed utilizing a surgical navigation system, were analyzed and compared. Final screw placement was compared to initial surgical plans using the navigation system, and the final screw locations were analyzed on the basis of angular deviation from these planned trajectories as well as screw translation within a critical reference plane. The power driver was found to insignificantly decrease the resulting angular deviation of these pedicle screws with a mean deviation of 3.35 degrees compared to 3.44 degrees with the manual driver (p = 0.853). Conversely, the power driver was found to increase the translational distance in the critical region, with mean deviations of 2.45 mm for the power driver compared to 1.54 mm with the manual driver. The increase in translational deviation was significant (p = 0.002) indicating that there may be some loss in performance from the adoption of the power driver.