Retinal ganglion cell repopulation for vision restoration in optic neuropathy: a roadmap from the RReSTORe Consortium.

Retinal ganglion cell (RGC) death in glaucoma and other optic neuropathies results in irreversible vision loss due to the mammalian central nervous system's limited regenerative capacity. RGC repopulation is a promising therapeutic approach to reverse vision loss from optic neuropathies if the newly introduced neurons can reestablish functional retinal and thalamic circuits. In theory, RGCs might be repopulated through the transplantation of stem cell-derived neurons or via the induction of endogenous transdifferentiation. The RGC Repopulation, Stem Cell Transplantation, and Optic Nerve Regeneration (RReSTORe) Consortium was established to address the challenges associated with the therapeutic repair of the visual pathway in optic neuropathy. In 2022, the RReSTORe Consortium initiated ongoing international collaborative discussions to advance the RGC repopulation field and has identified five critical areas of focus: (1) RGC development and differentiation, (2) Transplantation methods and models, (3) RGC survival, maturation, and host interactions, (4) Inner retinal wiring, and (5) Eye-to-brain connectivity. Here, we discuss the most pertinent questions and challenges that exist on the path to clinical translation and suggest experimental directions to propel this work going forward. Using these five subtopic discussion groups (SDGs) as a framework, we suggest multidisciplinary approaches to restore the diseased visual pathway by leveraging groundbreaking insights from developmental neuroscience, stem cell biology, molecular biology, optical imaging, animal models of optic neuropathy, immunology & immunotolerance, neuropathology & neuroprotection, materials science & biomedical engineering, and regenerative neuroscience. While significant hurdles remain, the RReSTORe Consortium's efforts provide a comprehensive roadmap for advancing the RGC repopulation field and hold potential for transformative progress in restoring vision in patients suffering from optic neuropathies.

Lipidomics Analysis with Triple Quadrupole Mass Spectrometry.

Lipids serve an essential role in multiple cellular functions including signaling, metabolism, energy storage, and membrane constitution. Lipidomics, the study of lipids using analytical chemistry, allows for the study of disease states and cellular metabolism. Shotgun lipidomics is a technique that involves direct-infusion electrospray ionization (ESI) and analysis with a triple quadrupole mass spectrometer. Triple quadrupole mass spectrometry is ideally suited for lipidomics analysis because it allows for class-specific identification of lipids. Individual lipid class can be identified by the adjustment of three parameters-collision energy, ion mode, and scan type. This chapter describes the use of a triple quadrupole mass spectrometer, the TSQ Quantum Access MAX, to perform lipidomics analysis with high sensitivity, accuracy, and precision.

Analysis of Cholesterol from the Liver Using Gas Chromatography-Mass Spectrometry.

Cholesterol is an essential lipid molecule for several biological functions including the proper functioning of cell membranes, lipoproteins, and lipid rafts, as well as the synthesis of bile acids, vitamin D, and steroid hormones. Cholesterol can be extracted from liver tissue by multiple methods of lipid extraction. Subsequently, gas chromatography-mass spectrometry (GC-MS) can be used to obtain the highest level of sensitivity and selectivity in the analysis of cholesterol. This chapter describes two methods of lipid extraction for liver tissue, Bligh and Dyer and methyl tertiary butyl ether (MTBE), followed by an analysis with GC-MS.

Management of complex surgical wounds of the back: identifying an evidence-based approach.

BACKGROUND: Postoperative dehiscence and surgical site infection after spinal surgery can carry serious morbidity. Multidisciplinary involvement of plastic surgery is essential to minimizing morbidity and achieving definitive closure. However, a standardized approach is lacking. The aim of this study was to identify effective reconstructive interventions for the basis of an evidence-based management protocol. METHODS: A retrospective review was performed at a single tertiary institution for 45 patients who required 53 reconstruction procedures with plastic surgery for wounds secondary to spinal surgery from 2010 to 2019. Statistical analysis was performed for demographics, comorbidities, and treatment methods. Primary outcomes were postoperative complications, including dehiscence, seroma, and infection. The secondary outcome was time to healing. RESULTS: The overall complication rate was 32%, with dehiscence occurring in 17%, seroma in 15% and infection in 11% of cases. Median follow-up was 10 months (interquartile range, 4-23). Use of antibiotic beads did not affect rate of infection occurrence after wound closure (P=0.146). Use of incisional negative pressure wound therapy (iNPWT) was significant for reduced time to healing (P=0.001). Patients treated without iNPWT healed at median of 67.5 days while the patients who received iNPWT healed in 33 days. Demographics and comorbidities between these two groups were similar. CONCLUSIONS: This data provides groundwork for an evidence-based approach to soft tissue reconstruction and management of dehiscence after spinal surgery. Timely involvement of plastic surgery in high-risk patients and utilization of evidence-based interventions such as iNPWT are essential for improving outcomes in this population.