Rac1 , a subunit of NADPH oxidase , plays an important role in directed endothelial cell motility. We reported previously that Rac1 activation was necessary for choroidal endothelial cell migration across the retinal pigment epithelium , a critical step in the development of vision-threatening neovascular age-related macular degeneration. Here we explored the roles of Rac1 and NADPH oxidase activation in response to vascular endothelial growth factor treatment in vitro and in a model of laser-induced choroidal neovascularization. We found that vascular endothelial growth factor induced the activation of Rac1 and of NADPH oxidase in cultured human choroidal endothelial cells. Further , vascular endothelial growth factor led to heightened generation of reactive oxygen species from cultured human choroidal endothelial cells, which was prevented by the NADPH oxidase inhibitors , apocynin and diphenyleneiodonium , or the antioxidant , N-acetyl-L-cysteine.
BackgroundAdvances in digital imaging, screen technology, and optics have led to the development of extracorporeal telescopes, also known as exoscopes, as alternatives to surgical loupes (SLs) and traditional operating microscopes (OMs) for surgical magnification. Theoretical advantages of the exoscope over conventional devices include improved surgeon ergonomics; superior three‐dimensional, high‐definition optics; and greater ease‐of‐use. The ORBEYE exoscope, in particular, has demonstrated early efficacy in the surgical arena. The purpose of this study was to compare the ORBEYE with conventional microscopy.MethodsIn this case–control pilot study, we compared the ORBEYE (n = 22) with conventional microscopy (n = 27) across 49 consecutive microsurgical cases during a 6‐week period. Both visualization methods consisted of breast, and head and neck cases, while the ORBEYE was also used for extremity and lymphedema microsurgical cases. The ORBEYE was utilized during flap dissection and microvascular anastomosis. Baseline demographics, operative time, ischemia time, and intra‐ and postoperative microvascular complications were examined and compared. Attending surgeons completed an ergonomics and performance survey postoperatively comparing the ORBEYE with their previous use of SL/OM using a 5‐point Likert scale.ResultsThere was no difference in operative time (507 ± 132 min vs. 522 ± 139, p = .714), ischemia time (77.9 ± 31.4 min vs. 77.5 ± 36.0, p = .972), or microsurgical complications (0% vs. 4%, p = 1) between the ORBEYE and conventional microscopy groups. In a survey administered immediately postoperatively, surgeons reported favorable ergonomics, excellent image quality, and ease of equipment manipulation using the exoscope.ConclusionsThe ORBEYE is an effective microsurgical tool and may be considered as an alternative to conventional optical magnification technology.
Hypothesis Cochlear trauma due to electrode insertion can be detected in acoustic responses to low frequencies in an animal model with a hearing condition similar to patients using electroacoustic stimulation. Background Clinical evidence suggests that intracochlear damage during cochlear implantation negatively affects residual hearing. Recently, we demonstrated the utility of acoustically evoked potentials to detect cochlear trauma in normal hearing gerbils. Here, gerbils with noise-induced hearing loss were used to investigate the effects of remote trauma on residual hearing. Methods Gerbils underwent high-pass (4 kHz cutoff) noise exposure to produce sloping hearing loss. After one-month recovery, each animal’s hearing loss was determined from ABRs and baseline intracochlear recording of the cochlear microphonic (CM) and compound action potential (CAP) obtained at the round window. Subsequently, electrode insertions were performed to produce basal trauma while the acoustically generated potentials to a 1 kHz tone burst were recorded after each step of electrode advancement. Hair cell counts were made to characterize the noise damage and cochlear whole mounts were used to identify cochlear trauma due to the electrode. Results The noise exposure paradigm produced a pattern of hair cell, ABR and intracochlear potential losses that closely mimicked that of EAS patients. Trauma in the basal turn, in the 15 – 30 kHz portion of the deafened region, remote from preserved hair cells, induced a decline in intracochlear acoustic responses to the hearing preserved frequency of 1 kHz. Conclusions The results indicate that a recording algorithm based on physiological markers to low frequency acoustic stimuli can identify cochlear trauma during implantation. Future work will focus on translating these results for use with current cochlear implant technology in humans.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.