Liquid-biopsy proteomics combined with AI identifies cellular drivers of eye aging and disease in vivo.

Single-cell analysis in living humans is essential for understanding disease mechanisms, but it is impractical in non-regenerative organs, such as the eye and brain, because tissue biopsies would cause serious damage. We resolve this problem by integrating proteomics of liquid biopsies with single-cell transcriptomics from all known ocular cell types to trace the cellular origin of 5,953 proteins detected in the aqueous humor. We identified hundreds of cell-specific protein markers, including for individual retinal cell types. Surprisingly, our results reveal that retinal degeneration occurs in Parkinson's disease, and the cells driving diabetic retinopathy switch with disease stage. Finally, we developed artificial intelligence (AI) models to assess individual cellular aging and found that many eye diseases not associated with chronological age undergo accelerated molecular aging of disease-specific cell types. Our approach, which can be applied to other organ systems, has the potential to transform molecular diagnostics and prognostics while uncovering new cellular disease and aging mechanisms.

Noncanonical autophagy promotes the visual cycle.

Phagocytosis and degradation of photoreceptor outer segments (POS) by retinal pigment epithelium (RPE) is fundamental to vision. Autophagy is also responsible for bulk degradation of cellular components, but its role in POS degradation is not well understood. We report that the morning burst of RPE phagocytosis coincided with the enzymatic conversion of autophagy protein LC3 to its lipidated form. LC3 associated with single-membrane phagosomes containing engulfed POS in an Atg5-dependent manner that required Beclin1, but not the autophagy preinitiation complex. The importance of this process was verified in mice with Atg5-deficient RPE cells that showed evidence of disrupted lysosomal processing. These mice also exhibited decreased photoreceptor responses to light stimuli and decreased chromophore levels that were restored with exogenous retinoid supplementation. These results establish that the interplay of phagocytosis and autophagy within the RPE is required for both POS degradation and the maintenance of retinoid levels to support vision.

The CoQ oxidoreductase FSP1 acts parallel to GPX4 to inhibit ferroptosis.

Ferroptosis is a form of regulated cell death that is caused by the iron-dependent peroxidation of lipids1,2. The glutathione-dependent lipid hydroperoxidase glutathione peroxidase 4 (GPX4) prevents ferroptosis by converting lipid hydroperoxides into non-toxic lipid alcohols3,4. Ferroptosis has previously been implicated in the cell death that underlies several degenerative conditions2, and induction of ferroptosis by the inhibition of GPX4 has emerged as a therapeutic strategy to trigger cancer cell death5. However, sensitivity to GPX4 inhibitors varies greatly across cancer cell lines6, which suggests that additional factors govern resistance to ferroptosis. Here, using a synthetic lethal CRISPR-Cas9 screen, we identify ferroptosis suppressor protein 1 (FSP1) (previously known as apoptosis-inducing factor mitochondrial 2 (AIFM2)) as a potent ferroptosis-resistance factor. Our data indicate that myristoylation recruits FSP1 to the plasma membrane where it functions as an oxidoreductase that reduces coenzyme Q10 (CoQ) (also known as ubiquinone-10), which acts as a lipophilic radical-trapping antioxidant that halts the propagation of lipid peroxides. We further find that FSP1 expression positively correlates with ferroptosis resistance across hundreds of cancer cell lines, and that FSP1 mediates resistance to ferroptosis in lung cancer cells in culture and in mouse tumour xenografts. Thus, our data identify FSP1 as a key component of a non-mitochondrial CoQ antioxidant system that acts in parallel to the canonical glutathione-based GPX4 pathway. These findings define a ferroptosis suppression pathway and indicate that pharmacological inhibition of FSP1 may provide an effective strategy to sensitize cancer cells to ferroptosis-inducing chemotherapeutic agents.

PROPHYLACTIC TREATMENT OF LATTICE DEGENERATION IN FELLOW EYES AFTER REPAIR OF UNCOMPLICATED PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To evaluate prophylactic treatment (PTx) of lattice degeneration (LD) on retinal tear (RT) and rhegmatogenous retinal detachment (RRD) risk in fellow eyes of patients after primary RRD repair in the first eye. METHODS: This was a consecutive case series with cohort control involving patients with RRD repair from January 1, 2013, through December 31, 2017. Patients received PTx (PTx cohort) or no PTx (No-PTx cohort) in fellow eye with 5-year follow-up. Primary outcome measure was proportion with new fellow eye RT/RRD. Secondary outcomes included logarithm of minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) and status of myopia, posterior vitreous detachment, and pseudophakia. RESULTS: Four hundred ninety-eight patients were divided into 146 and 352 in PTx and No-PTx cohorts, respectively. PTx cohort developed significantly ( P < 0.05) fewer RT/RRD (17%) than No-PTx cohort (41%). PTx significantly ( P < 0.05) lowered RT/RRD irrespective of posterior vitreous detachment and myopia status. PTx patients undergoing phacoemulsification demonstrated significantly ( P < 0.05) less RT/RRD (22%) than No-PTx cohort (31%). There was no significant ( P = 0.96) final BCVA difference between PTx (median = 0 logMAR) and No-PTx (median = 0 logMAR) cohorts. CONCLUSION: PTx of asymptomatic fellow eye LD reduced RT/RRD risk.

BILATERAL EYE PATCHING MAY IMPROVE CLINICAL OUTCOMES FOR ACUTE PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: Evaluate preoperative bilateral eye patching (BEP) on subretinal fluid and vision in acute primary rhegmatogenous retinal detachments (RRDs). METHODS: Retrospective nonrandomized interventional study of 335 patients with RRD undergoing BEP until surgery (BEP cohort) and separated by the percentage of full-time compliance: high (≥90%), medium (>90% but ≥50%), and low (<50%). Those declining BEP were included (control). All underwent surgery and were followed for ≥3 months. Imaging was obtained immediately before surgery. Best-corrected visual acuity was measured at the longest follow-up and immediately before surgery. SRF and foveal status immediately before surgery were analyzed. RESULTS: Two hundred and forty and 95 patients were in BEP and control cohorts, respectively. Thirty patients presented immediately before surgery for analysis. High (64%) and medium (35%) compliance showed significantly greater ( P < 0.01) SRF reduction compared with low (4%) and control (3%). Mac-off RRD showed significantly greater ( P < 0.01) foveal reattachment with high (29%) and medium (8%) compliance compared with low (2%) and control (1%). Mac-on RRD demonstrated no significant differences ( P ≥ 0.51) in final best-corrected visual acuity among high (0 logarithm of the minimum angle of resolution [logMAR] [median], 20/20 Snellen), medium (0.10 logMAR, 20/25 Snellen), low (0.10 logMAR), and control cohorts (0.10 logMAR). Mac-off RRD demonstrated significantly better final best-corrected visual acuity with high compliance (0.30 logMAR, 20/40 Snellen) compared with low (0.40 logMAR, 20/50 Snellen; P = 0.04) and control (0.60 logMAR, 20/80 Snellen; P = 0.02). CONCLUSION: Preoperative BEP can stabilize or improve subretinal fluid in acute primary RRD. Patients with BEP >50% of the time experienced the greatest benefits.

Relationship between piperacillin concentrations, clinical factors and piperacillin/tazobactam-associated acute kidney injury.

BACKGROUND: Piperacillin/tazobactam, a commonly used antibiotic, is associated with acute kidney injury (AKI). The relationship between piperacillin concentrations and AKI remains unknown. OBJECTIVE: Estimate piperacillin exposures in critically ill children and young adults administered piperacillin/tazobactam to identify concentrations and clinical factors associated with piperacillin-associated AKI. PATIENTS AND METHODS: We assessed piperacillin pharmacokinetics in 107 patients admitted to the paediatric ICU who received at least one dose of piperacillin/tazobactam. Piperacillin AUC, highest peak (Cmax) and highest trough (Cmin) in the first 24 hours of therapy were estimated. Piperacillin-associated AKI was defined as Kidney Disease: Improving Global Outcomes (KDIGO) Stage 2/3 AKI present >24 hours after initial piperacillin/tazobactam dose. Likelihood of piperacillin-associated AKI was rated using the Naranjo Adverse Drug Reaction Probability Scale. Multivariable logistic regression was performed to identify patient and clinical predictors of piperacillin-associated AKI. RESULTS: Out of 107 patients, 16 (15%) were rated as possibly or probably having piperacillin-associated AKI. Estimated AUC and highest Cmin in the first 24 hours were higher in patients with piperacillin-associated AKI (2042 versus 1445 mg*h/L, P = 0.03; 50.1 versus 10.7 mg/L, P < 0.001). Logistic regression showed predictors of piperacillin-associated AKI included higher Cmin (OR: 5.4, 95% CI: 1.7-23) and age (OR: 1.13, 95% CI: 1.05-1.25). CONCLUSIONS: We show a relationship between estimated piperacillin AUC and highest Cmin in the first 24 hours of piperacillin/tazobactam therapy and piperacillin-associated AKI, suggesting total piperacillin exposure early in the course is associated with AKI development. These data could serve as the foundation for implementation of model-informed precision dosing to reduce AKI incidence in patients given piperacillin/tazobactam.

Cefepime pharmacokinetics in critically ill children and young adults undergoing continuous kidney replacement therapy.

OBJECTIVES: Cefepime is an antibiotic commonly used to treat sepsis and is cleared by renal excretion. Cefepime dosing requires adjustment in patients with decreased kidney function and in those receiving continuous kidney replacement therapy (CKRT). We aimed to characterize cefepime PK in a diverse cohort of critically ill paediatric patients on CKRT. METHODS: Patients were identified from an ongoing pharmacokinetic/pharmacodynamic (PK/PD) study of beta-lactam antibiotics, and were included if they had received at least two cefepime doses in the ICU and were on CKRT for at least 24 h. PK parameters were estimated using MwPharm++ with Bayesian estimation and a paediatric population PK model. Target attainment was assessed as time of free cefepime concentrations above minimum inhibitory concentration (fT > 1× or 4 × MIC). RESULTS: Seven patients were included in the study (ages 2 to 20 years). CKRT indications included liver failure (n = 1), renal failure (n = 4) and fluid overload (n = 2). Total effluent flow rates ranged from 1833 to 3115 (mean 2603) mL/1.73 m2/h, while clearance was 2.11-3.70 (mean 3.0) L/h/70 kg. Effluent flows were lower, but clearance and fT > MIC were similar to paediatric data published previously. Using Pseudomonas aeruginosa MIC breakpoints, all patients had 100% of dosing interval above MIC, but only one had 100% of dosing interval above 4× MIC. CONCLUSIONS: Since most patients failed to attain stringent targets of 100% fT > 4×  MIC, model-informed precision dosing may benefit such patients.

Papain-Based Solubilization of Decellularized Extracellular Matrix for the Preparation of Bioactive, Thermosensitive Pregels.

Solubilized, gel-forming decellularized extracellular matrix (dECM) is used in a wide range of basic and translational research and due to its inherent bioactivity can promote structural and functional tissue remodeling. The animal-derived protease pepsin has become the standard proteolytic enzyme for the solubilization of almost all types of collagen-based dECM. In this study, pepsin was compared with papain, α-amylase, and collagenase for their potential to solubilize porcine liver dECM. Maximum preservation of bioactive components and native dECM properties was used as a decisive criterion for further application of the enzymes, with emphasis on minimal destruction of the protein structure and maintained capacity for physical thermogelation at neutral pH. The solubilized dECM digests, and/or their physically gelled hydrogels were characterized for their rheological properties, gelation kinetics, GAG content, proteomic composition, and growth factor profile. This study highlights papain as a plant-derived enzyme that can serve as a cost-effective alternative to animal-derived pepsin for the efficient solubilization of dECM. The resulting homogeneous papain-digested dECM preserved its thermally triggered gelation properties similar to pepsin digests, and the corresponding dECM hydrogels demonstrated their enhanced bioadhesiveness in single-cell force spectroscopy experiments with fibroblasts. The viability and proliferation of human HepaRG cells on dECM gels were similar to those on pure rat tail collagen type I gels. Papain is not only highly effective and economically attractive for dECM solubilization but also particularly interesting when digesting human-tissue-derived dECM for regenerative applications, where animal-derived materials are to be avoided.

Ceftriaxone Pharmacokinetics and Pharmacodynamics in 2 Pediatric Patients on Extracorporeal Membrane Oxygenation Therapy.

BACKGROUND: Critically ill patients with cardiac or respiratory failure may require extracorporeal membrane oxygenation (ECMO). Antibiotics are frequently administered when the suspected cause of organ failure is an infection. Ceftriaxone, a ß-lactam antibiotic, is commonly used in patients who are critically ill. Although studies in adults on ECMO have suggested minimal impact on ceftriaxone pharmacokinetics, limited research exists on ceftriaxone pharmacokinetics/pharmacodynamics (PK/PD) in pediatric ECMO patients. We report the PK profiles and target attainment of 2 pediatric patients on ECMO who received ceftriaxone. METHODS: Ceftriaxone concentrations were measured in 2 pediatric patients on ECMO using scavenged opportunistic sampling. PK profiles were generated and individual PK parameters were estimated using measured free ceftriaxone concentrations and a published population PK model in children who are critically ill, using Bayesian estimation. RESULTS: Patient 1, an 11-year-old boy on venovenous ECMO for respiratory failure received 2 doses of 52 mg/kg ceftriaxone 12 hours apart while on ECMO and additional doses every 12 hours off ECMO. On ECMO, ceftriaxone clearance was 13.0 L/h/70 kg compared with 7.6 L/h/70 kg off ECMO, whereas the model-predicted mean clearance in children who are critically ill without ECMO support was 6.54 L/h/70 kg. Patient 2, a 2-year-old boy on venoarterial ECMO due to cardiac arrest received 50 mg/kg ceftriaxone every 12 hours while on ECMO for >7 days. Only clearance while on ECMO could be estimated (9.1 L/h/70 kg). Trough concentrations in both patients were >1 mg/L (the breakpoint for Streptococcus pneumoniae ) while on ECMO. CONCLUSIONS: ECMO increased ceftriaxone clearance above the model-predicted clearances in the 2 pediatric patients studied. Twelve-hour dosing allowed concentrations to remain above the breakpoint for commonly targeted bacteria but not 4 times the breakpoint in one patient, suggesting that precision dosing may be beneficial to ensure target attainment in children on ECMO.

CLINICAL OUTCOMES OF ACUTE ENDOPHTHALMITIS AFTER INTRAVITREAL DELIVERY OF VASCULAR ENDOTHELIAL GROWTH FACTOR INHIBITORS VERSUS STEROIDS.

PURPOSE: To compare patients with acute endophthalmitis after intravitreal injection of vascular endothelial growth factor (VEGF) inhibitors vs. steroids. METHODS: Retrospective single-center, nonrandomized interventional study from 2013 to 2021.Patients underwent vitreous biopsy before initiating treatment and were divided into the following cohorts: (1) anti-VEGF managed medically (T&I-anti-VEGF), (2) anti-VEGF managed by immediate pars plana vitrectomy (PPV-anti-VEGF), and (3) steroid therapy and managed medically or by pars plana vitrectomy (steroid). RESULTS: A total of 141 patients were analyzed. The steroid cohort demonstrated significantly worse presenting (median = 2.80 logarithm of the minimum angle of resolution [logMAR]; P ≤ 0.01) and final (median = 2.30 logMAR) best-corrected visual acuity compared with T&I-anti-VEGF (presenting: median = 2.00 logMAR; final: median = 0.40 logMAR) and pars plana vitrectomy-anti-VEGF cohorts (presenting: median = 2.30 logMAR; final: median = 0.48 logMAR). There was no significant ( P = 0.33) difference in the final best-corrected visual acuity between T&I-anti-VEGF and pars plana vitrectomy-anti-VEGF cohorts. There were no significant ( P ≥ 0.63) differences among cohorts in best-corrected visual acuity before acute endophthalmitis diagnosis (T&I-anti-VEGF: median = 0.40 logMAR; pars plana vitrectomy-anti-VEGF: median = 0.40 logMAR; steroid: median = 0.44 logMAR). Microbial cultures revealed similar profiles for all cohorts. CONCLUSION: Acute endophthalmitis after intravitreal injection steroid therapy had worse outcomes compared with anti-VEGF therapy.

Population Pharmacokinetic Modeling of Total and Free Ceftriaxone in Critically Ill Children and Young Adults and Monte Carlo Simulations Support Twice Daily Dosing for Target Attainment.

Critical illness, including sepsis, causes significant pathophysiologic changes that alter the pharmacokinetics (PK) of antibiotics. Ceftriaxone is one of the most prescribed antibiotics in patients admitted to the pediatric intensive care unit (PICU). We sought to develop population PK models of both total ceftriaxone and free ceftriaxone in children admitted to a single-center PICU using a scavenged opportunistic sampling approach. We tested if the presence of sepsis and phase of illness (before or after 48 h of antibiotic treatment) altered ceftriaxone PK parameters. We performed Monte Carlo simulations to evaluate whether dosing regimens commonly used in PICUs in the United States (50 mg/kg of body weight every 12 h versus 24 h) resulted in adequate antimicrobial coverage. We found that a two-compartment model best described both total and free ceftriaxone concentrations. For free concentrations, the population clearance value is 6.54 L/h/70 kg, central volume is 25.4 L/70 kg, and peripheral volume is 19.6 L/70 kg. For both models, we found that allometric weight scaling, postmenstrual age, creatinine clearance, and daily highest temperature had significant effects on clearance. The presence of sepsis or phase of illness did not have a significant effect on clearance or volume of distribution. Monte Carlo simulations demonstrated that to achieve free concentrations above 1 µg/ml for 100% of the dosing intervals, a dosing regimen of 50 mg/kg every 12 h is recommended for most patients. A continuous infusion could be considered if the target is to maintain free concentrations four times above the MICs (4 µg/ml).

Fibrin Glue and Conduit Form a Composite Structure in Digital Nerve Repair.

Repair of severed nerves without autograft or allograft has included suture, suture with glue alone, suture with conduit and suture with glue augmentation to conduit, where use of conduit is considered for separation of the nerve ends from 5 mm to 3 cm. Repairs must not only serve acutely to provide apposition of nerve ends but must enable the healing of the nerve. Using biological conduit can place suture at the ends of the conduit while fibrin glue alone eliminates suture but with limited strength. The combination of conduit and glue offers the growth guidance of conduit with sufficient strength from the glue to maintain the nerve within the conduit. The role of fibrin glue in the integrity of the repair remains an open question, however. We sought to determine the factors in the strength of a glue-conduit-nerve construct and include consideration of standard suture repair. Fresh-frozen cadaveric digital nerves were repaired with suture alone, with glue alone or with suture and glue together and then loaded to failure. Previously tested specimens with conduit, suture and glue were considered for comparison. The suture alone (2.02 N) and suture with glue (2.24 N) were not statistically different from each other but were statistically stronger than glue alone (0.15 N). When compared to the earlier results of the strength of conduit with glue (0.65 N), these simple results show that the glue and conduit act together. The increased area over which the glue adheres to the nerve and conduit creates a composite structure stronger than either alone.

The Influence of Universal Face Mask Use on Endophthalmitis Risk after Intravitreal Anti-Vascular Endothelial Growth Factor Injections.

PURPOSE: Routine use of face masks for patients and physicians during intravitreal anti-vascular endothelial growth factor (VEGF) injections has increased with the emergence of the coronavirus disease 2019 pandemic. This study evaluates the impact of universal face mask use on rates and outcomes of post-injection endophthalmitis (PIE). DESIGN: Retrospective, multicenter, comparative cohort study. PARTICIPANTS: Eyes receiving intravitreal anti-VEGF injections from October 1, 2019, to July 31, 2020, at 12 centers. METHODS: Cases were divided into a "no face mask" group if no face masks were worn by the physician or patient during intravitreal injections or a "universal face mask" group if face masks were worn by the physician, ancillary staff, and patient during intravitreal injections. MAIN OUTCOME MEASURES: Rate of endophthalmitis, microbial spectrum, and visual acuity (VA). RESULTS: Of 505 968 intravitreal injections administered in 110 547 eyes, 85 of 294 514 (0.0289%; 1 in 3464 injections) cases of presumed endophthalmitis occurred in the "no face mask" group, and 45 of 211 454 (0.0213%; 1 in 4699) cases occurred in the "universal face mask" group (odds ratio [OR], 0.74; 95% confidence interval [CI], 0.51-1.18; P = 0.097). In the "no face mask" group, there were 27 cases (0.0092%; 1 in 10 908 injections) of culture-positive endophthalmitis compared with 9 cases (0.004%; 1 in 23 494) in the "universal face mask" group (OR, 0.46; 95% CI, 0.22-0.99; P = 0.041). Three cases of oral flora-associated endophthalmitis occurred in the "no face mask" group (0.001%; 1 in 98 171 injections) compared with 1 (0.0005%; 1 in 211 454) in the "universal face mask" group (P = 0.645). Patients presented a mean (range) 4.9 (1-30) days after the causative injection, and mean logarithm of the minimum angle of resolution (logMAR) VA at endophthalmitis presentation was 2.04 (~20/2200) for "no face mask" group compared with 1.65 (~20/900) for the "universal face mask" group (P = 0.022), although no difference was observed 3 months after treatment (P = 0.764). CONCLUSIONS: In a large, multicenter, retrospective study, physician and patient face mask use during intravitreal anti-VEGF injections did not alter the risk of presumed acute-onset bacterial endophthalmitis, but there was a reduced rate of culture-positive endophthalmitis. Three months after presentation, there was no difference in VA between the groups.

Paediatric ganciclovir dosing in extracorporeal membrane oxygenation: Is standard dosing good enough?

WHAT IS KNOWN AND OBJECTIVE: Ganciclovir is a first-line antiviral agent to treat cytomegalovirus disease in immunocomprimised patients. Ganciclovir pharmacokinetics in ECMO is unknown. CASE DESCRIPTION: A 6-year-old with a stage IV extra-renal rhabdoid tumor with respiratory failure leading to extracorporeal membrane oxygenation had increasing serum CMV DNAemia while on ganciclovir. WHAT IS NEW AND CONCLUSION: This is the first case report of ganciclovir pharmacokinetics in either paediatric or adult ECMO populations. Recommended dosing provided a low, subtherapeutic AUC24 with an associated increase CMV viral load. Higher doses of ganciclovir may be required in ECMO patients, especially without concurrent CRRT.

Improvement of Normothermic Ex Vivo Machine Perfusion of Rat Liver Grafts by Dialysis and Kupffer Cell Inhibition With Glycine.

Normothermic ex vivo liver machine perfusion might be a superior preservation strategy for liver grafts from extended criteria donors. However, standardized small animal models are not available for basic research on machine perfusion of liver grafts. A laboratory-scaled perfusion system was developed consisting of a custom-made perfusion chamber, a pressure-controlled roller pump, and an oxygenator. Male Wistar rat livers were perfused via the portal vein for 6 hours using oxygenated culture medium supplemented with rat erythrocytes. A separate circuit was connected via a dialysis membrane to the main circuit for plasma volume expansion. Glycine was added to the flush solution, the perfusate, and the perfusion circuit. Portal pressure and transaminase release were stable over the perfusion period. Dialysis significantly decreased the potassium concentration of the perfusate and led to significantly higher bile and total urea production. Hematoxylin-eosin staining and immunostaining for single-stranded DNA and activated caspase 3 showed less sinusoidal dilatation and tissue damage in livers treated with dialysis and glycine. Although Kupffer cells were preserved, tumor necrosis factor α messenger RNA levels were significantly decreased by both treatments. For proof of concept, the optimized perfusion protocol was tested with donation after circulatory death (DCD) grafts, resulting in significantly lower transaminase release into the perfusate and preserved liver architecture compared with baseline perfusion. In conclusion, our laboratory-scaled normothermic portovenous ex vivo liver perfusion system enables rat liver preservation for 6 hours. Both dialysis and glycine treatment were shown to be synergistic for preservation of the integrity of normal and DCD liver grafts.

Real world usability analysis of two augmented reality headsets in visceral surgery.

Recent developments in the field of augmented reality (AR) have enabled new use cases in surgery. Initial set-up of an appropriate infrastructure for maintaining an AR surgical workflow requires investment in appropriate hardware. We compared the usability of the Microsoft HoloLens and Meta 2 head mounted displays (HMDs). Fifteen medicine students tested each device and were questioned with a variant of the System Usability Scale (SUS). Two surgeons independently tested the devices in an intraoperative setting. In our adapted SUS, ergonomics, ease of use, and visual clarity of the display did not differ significantly between HMD groups. The field of view (FOV) was smaller in the Microsoft HoloLens than the Meta 2 and significantly more study subjects (80% vs. 13.3%; P < 0.001) felt limited through the FOV. Intraoperatively, decreased mobility due to the necessity of an AC adapter and additional computing device for the Meta 2 proved to be limiting. Object stability was rated superior in the Microsoft HoloLens than the Meta 2 by our surgeons and lead to increased use. In summary, after examination of the Meta 2 and the Microsoft HoloLens, we found key advantages in the Microsoft HoloLens which provided palpable benefits in a surgical setting.

Teburu-Open source 3D printable bioreactor for tissue slices as dynamic three-dimensional cell culture models.

Three-dimensional tissue cultures are important models for the study of cell-cell and cell-matrix interactions, as well as, to investigate tissue repair and reconstruction pathways. Therefore, we designed a reproducible and easy to handle printable bioreactor system (Teburu), that is applicable for different approaches of pathway investigation and targeted tissue repair using human tissue slices as a three-dimensional cell culture model. Here, we definitively describe Teburu as a controlled environment to reseed a 500-µm thick decellularized human liver slice using human mesenchymal stroma cells. During a cultivation period of eight days, Teburu, as a semi-open and low consumption system, was capable to maintain steady pH and oxygenation levels. Its combination with additional modules delivers an applicability for a wide range of tissue engineering approaches under optimal culture conditions.

STEM CELL THERAPIES, GENE-BASED THERAPIES, OPTOGENETICS, AND RETINAL PROSTHETICS: Current State and Implications for the Future.

PURPOSE: To review and discuss current innovations and future implications of promising biotechnology and biomedical offerings in the field of retina. We focus on therapies that have already emerged as clinical offerings or are poised to do so. METHODS: Literature review and commentary focusing on stem cell therapies, gene-based therapies, optogenetic therapies, and retinal prosthetic devices. RESULTS: The technologies discussed herein are some of the more recent promising biotechnology and biomedical developments within the field of retina. Retinal prosthetic devices and gene-based therapies both have an FDA-approved product for ophthalmology, and many other offerings (including optogenetics) are in the pipeline. Stem cell therapies offer personalized medicine through novel regenerative mechanisms but entail complex ethical and reimbursement challenges. CONCLUSION: Stem cell therapies, gene-based therapies, optogenetics, and retinal prosthetic devices represent a new era of biotechnological and biomedical progress. These bring new ethical, regulatory, care delivery, and reimbursement challenges. By addressing these issues proactively, we may accelerate delivery of care to patients in a safe, efficient, and value-based manner.

Anatomy, Etiology, and Management of Scapular Winging.

Scapular winging is a painful and debilitating condition. The composite scapular motion of rotation, abduction, and tilting is necessary for proper shoulder function. Weakness or loss of scapular mechanics can lead to difficulties with elevation of the arm and lifting objects. The most common causes reported in the literature for scapular winging are dysfunction of the serratus anterior from long thoracic nerve injury causing medial winging or dysfunction of the trapezius from spinal accessory nerve injury causing lateral winging. Most reviews and teaching focus on these etiologies. However, acute traumatic tears of the serratus anterior, trapezius, and rhomboids off of the scapula are important and under-recognized causes of scapular winging and dysfunction. This article will review the relevant anatomy, etiology, clinical evaluation, diagnostic testing, and treatment of scapular winging. It will also discuss the differences in diagnosis and management between scapular winging arising from neurogenic causes and traumatic muscular detachment.

A subpopulation of activated retinal macrophages selectively migrated to regions of cone photoreceptor stress, but had limited effect on cone death in a mouse model for type 2 Leber congenital amaurosis.

BACKGROUND: Studies of antigen presentation in retina using mice that expressed green fluorescent protein (GFP) from a transgenic CD11c promoter found that retinal GFPhi cells possessed antigen presentation function. Subsequent studies found that these high GFPhi cells preferentially localized to sites of retinal injury, consistent with their APC function. Interest in the roles of macrophages in degenerative CNS diseases led us to study the GFPhi cells in a retinal model of neurodegeneration. We asked if apoptotic cone photoreceptor cell death in Rpe65-/- knockout mice induced the GFPhi cells, explored their relationship to resident microglia (MG), and tested their role in cone survival. METHODS: Rpe65-/- mice were bred to CD11cGFP mice on the B6/J background. CD11cGFPRpe65-/- mice were also backcrossed to CX3CR1YFP-creERROSADTA mice so that CX3CR1+ mononuclear cells could be depleted by Tamoxifen. Retinas were analyzed by immunohistochemistry, confocal microscopy, fluorescence fundoscopy and flow cytometry. RESULTS: Elevated numbers of GFPhi cells were concentrated in photoreceptor cell layers of CD11cGFPRpe65-/- mice coinciding with the peak of cone death at 2 to 4weeks of age, and persisted for at least 14months. After the initial wave of cone loss, a slow progressive loss of cones was found that continued to retain GFPhi cells in the outer retina. Sustained, four-week Tamoxifen depletions of the GFPhi cells and MG in Rpe65-/- mice from day 13 to day 41, and from day 390 to day 420 promoted a small increase in cone survival. We found no evidence that the GFPhi cells were recruited from the circulation; all data pointed to a MG origin. MG and GFPhi cells were well segregated in the dystrophic retina; GFPhi cells were foremost in the photoreceptor cell layer, while MG were concentrated in the inner retina. CONCLUSIONS: The expression of GFP on a subset of retinal mononuclear cells in CD11cGFP mice identified a distinct population of cells performing functions previously attributed to MG. Although GFPhi cells dominated the macrophage response to cone death in the photoreceptor cell layer, their ablation led to only an incremental increase in cone survival. The ability to identify, ablate, and isolate these cells will facilitate analysis of this activated, antigen-presenting subset of MG.