Effect of photobiomodulation therapy on neuronal injuries by ouabain: the regulation of Na, K-ATPase; Src; and mitogen-activated protein kinase signaling pathway.

BACKGROUND: To determine whether photobiomodulation (PBM) rescued the disruption of Na+/Ca2+ homeostasis and mitochondrial membrane potential by ouabain; the Na, K-ATPase inhibitor. For PBM in this study, a 660 nm LED array was used at energy densities of 0.78, 1.56, 3.12, 6.24, and 9.36 J/cm2. RESULTS: HCN-2 neuronal cells treated with ouabain showed loss of cell polarity, disrupted cell morphology, and decreased cell viability, which were improved after PBM treatment. We found that ouabain-induced Na, K-ATPase inhibition promoted activation of downstream signaling through Src, Ras, and mitogen-activated protein kinase (MAPK), which were suppressed after PBM treatment. This provided evidence of Na, K-ATPase α-subunit inactivation and intracellular Ca2+ increase. In response to ouabain, we observed activation of Src and MAPK by Na, K-ATPase, decreased mitochondrial membrane potential, and Na+-dependent Ca2+ increases, which were restored by PBM treatment. CONCLUSIONS: This study demonstrated that Na+/K+ imbalance could be regulated by PBM treatment in neuronal cells, and we suggest that PBM is a potential therapeutic tool for Na, K-ATPase targeted neuronal diseases.

Reaching Target Communities in a Community Preschool Vision Screening Program.

PURPOSE: To develop a method to identify preschools with the greatest need for vision screening, correlations between socioeconomic status, preschool capacity, and rates of pediatric vision screenings performed by a community vision screening program were investigated. Geoinformatics mapping software was used to visually display the areas of greatest need. METHODS: Vision screening data from a community vision screening program, child care facility data from California Department of Social Services, and income data from the U.S. Census Bureau through ArcGIS software (Esri) were collected. When possible, data were consolidated at the ZIP code level. Kolmogorov-Smirnov analysis was used to determine correlations between data elements. Licensed child care facilities were scored on a scale (from 1 to 5) based on the socioeconomic status of the ZIP code and the facility capacity. The scoring system prioritized larger facilities in lower income communities to most efficiently use vision screening program resources. RESULTS: There was a positive correlation between the capacity of the child care facility and the median household income (P = .005). Second, we found a positive correlation between child care capacity and the median household income (P = .005). Licensed child care facilities were mapped and colored using GIS software according to their cumulative score. CONCLUSIONS: Challenges to vision screening in under-served communities include the lack of child care facilities and smaller facility size. The use of a scoring system and mapping software can direct vision screening programs to reach a greater number of children with the most efficient use of resources. [J Pediatr Ophthalmol Strabismus. 2022;59(6):375-379.].

Development and evaluation of rhinoplasty spreader graft suture simulator for novice surgeons.

OBJECTIVE: Surgical simulators aimed at mimicking elements of rhinoplasty surgery, specifically those aimed at improving cartilage suturing, are not available. Here, we present a surgical simulator for spreader graft placement that uses cartilage rather than synthetic materials and gauge improvement using objective measures for suture placement accuracy, speed, and efficiency of hand motion. METHODS: Twenty-two otolaryngologists in two groups (residents [10] and experts [12]) were instructed to secure the two spreader graft specimen into position with three mattress sutures on a nose model that used porcine septal cartilage as a proxy for the human counterpart. Hand motion was tracked using an electromagnetic position sensing device. The time required to complete the suture task, total hand displacement, cumulative number of hand motion direction changes, and accuracy of suture insertion were measured. These measurements were compared between the two cohort groups for construct validity. The subjects completed a survey to evaluate realism and value of the model. RESULTS: The expert group had a lower mean time required to complete the task (P < 0.05), total hand displacement (P < 0.01), and number of hand motion direction changes (P < 0.001). No significant difference was observed between the two groups in suture precision measurement. The subjects agreed on the face validity and usefulness of the trainer. CONCLUSIONS: Our study suggests that the simulator may be a useful tool to objectively gauge suturing efficiency. Devices such as this may be useful for developing skill with suturing cartilage tissue and potentially be used to assess resident acquisition of surgical skill. LEVEL OF EVIDENCE: NA Laryngoscope, 129:344-350, 2019.

Association of Electrochemical Therapy With Optical, Mechanical, and Acoustic Impedance Properties of Porcine Skin.

IMPORTANCE: The classic management of burn scars and other injuries to the skin has largely relied on soft-tissue transfer to resurface damaged tissue with local tissue transfer or skin graft placement. In situ generation of electrochemical reactions using needle electrodes and an application of current may be a new approach to treat scars and skin. OBJECTIVE: To examine the changes in optical, mechanical, and acoustic impedance properties in porcine skin after electrochemical therapy. DESIGN, SETTING, AND PARTICIPANTS: This preclinical pilot study, performed from August 1, 2015, to November 1, 2016, investigated the effects of localized pH-driven electrochemical therapy of ex vivo porcine skin using 24 skin samples. Platinum-plated needle electrodes were inserted into fresh porcine skin samples. A DC power supply provided a voltage of 4 to 5 V with a 3-minute application time. Specimens were analyzed using optical coherence tomography, optical coherence elastography, and ultrasonography. Ultrasonography was performed under 3 conditions (n = 2 per condition), optical coherence tomography was performed under 2 conditions (n = 2 per condition), and optical coherence elastography was performed under 2 conditions (n = 2 per condition). The remaining samples were used for the positive and negative control groups (n = 10). EXPOSURES: Platinum-plated needle electrodes were inserted into fresh porcine skin samples. A DC power supply provided a voltage of 4 to 5 V with a 3-minute application. MAIN OUTCOMES AND MEASURES: Tissue softening was observed at the anode and cathode sites as a result of electrochemical modification. Volumetric changes were noted using each optical and acoustic technique. RESULTS: A total of 24 ex vivo porcine skin samples were used for this pilot study. Optical coherence tomography measured spatial distribution of superficial tissue changes around each electrode site. At 4 V for 3 minutes, a total volumetric effect of 0.47 mm3 was found at the anode site and 0.51 mm3 at the cathode site. For 5 V for 3 minutes, a total volumetric effect of 0.85 mm3 was found at the anode site and 1.05 mm3 at the cathode site. CONCLUSIONS AND RELEVANCE: Electrochemical therapy is a low-cost technique that is on par with the costs of suture and scalpel. The use of electrochemical therapy to create mechanical and physiologic changes in tissue has the potential to locally remodel the soft-tissue matrix, which ultimately may lead to an inexpensive scar treatment or skin rejuvenation therapy. LEVEL OF EVIDENCE: NA.

Monitoring of Biological Changes in Electromechanical Reshaping of Cartilage Using Imaging Modalities.

Electromechanical reshaping (EMR) is a promising surgical technique used to reshape cartilage by direct current and mechanical deformation. It causes local stress relaxation and permanent alterations in the shape of cartilage. The major advantages of EMR are its minimally invasive nature and nonthermal electrochemical mechanism of action. The purpose of this study is to validate that EMR does not cause thermal damage and to observe structural changes in post-EMR cartilage using several imaging modalities. Three imaging modality metrics were used to validate the performance of EMR by identifying structural deformation during cartilage reshaping: infrared thermography was used to sense the temperature of the flat cartilages (16.7°C at 6 V), optical coherence tomography (OCT) was used to examine the change in the cartilage by gauging deformation in the tissue matrix during EMR, and scanning electron microscopy (SEM) was used to show that EMR-treated cartilage is irregularly arranged and the thickness of collagen fibers varies, which affects the change in shape of the cartilage. In conclusion, the three imaging modalities reveal the nonthermal and electromechanical mechanisms of EMR and demonstrate that use of an EMR device is feasible for reshaping cartilage in a minimally invasive manner.

Simultaneous bilateral laser therapy accelerates recovery after noise-induced hearing loss in a rat model.

Noise-induced hearing loss is a common type of hearing loss. The effects of laser therapy have been investigated from various perspectives, including in wound healing, inflammation reduction, and nerve regeneration, as well as in hearing research. A promising feature of the laser is its capability to penetrate soft tissue; depending on the wavelength, laser energy can penetrate into the deepest part of the body without damaging non-target soft tissues. Based on this idea, we developed bilateral transtympanic laser therapy, which uses simultaneous laser irradiation in both ears, and evaluated the effects of bilateral laser therapy on cochlear damage caused by noise overexposure. Thus, the purpose of this research was to assess the benefits of simultaneous bilateral laser therapy compared with unilateral laser therapy and a control. Eighteen Sprague-Dawley rats were exposed to narrow-band noise at 115 dB SPL for 6 h. Multiple auditory brainstem responses were measured after each laser irradiation, and cochlear hair cells were counted after the 15th such irradiation. The penetration depth of the 808 nm laser was also measured after sacrifice. Approximately 5% of the laser energy reached the contralateral cochlea. Both bilateral and unilateral laser therapy decreased the hearing threshold after noise overstimulation in the rat model. The bilateral laser therapy group showed faster functional recovery at all tested frequencies compared with the unilateral laser therapy group. However, there was no difference in the endpoint ABR results or final hair cell survival, which was analyzed histologically.