Glucose hypometabolism prompts RAN translation and exacerbates C9orf72-related ALS/FTD phenotypes.

The most prevalent genetic cause of both amyotrophic lateral sclerosis and frontotemporal dementia is a (GGGGCC)n nucleotide repeat expansion (NRE) occurring in the first intron of the C9orf72 gene (C9). Brain glucose hypometabolism is consistently observed in C9-NRE carriers, even at pre-symptomatic stages, but its role in disease pathogenesis is unknown. Here, we show alterations in glucose metabolic pathways and ATP levels in the brains of asymptomatic C9-BAC mice. We find that, through activation of the GCN2 kinase, glucose hypometabolism drives the production of dipeptide repeat proteins (DPRs), impairs the survival of C9 patient-derived neurons, and triggers motor dysfunction in C9-BAC mice. We also show that one of the arginine-rich DPRs (PR) could directly contribute to glucose metabolism and metabolic stress by inhibiting glucose uptake in neurons. Our findings provide a potential mechanistic link between energy imbalances and C9-ALS/FTD pathogenesis and suggest a feedforward loop model with potential opportunities for therapeutic intervention.

Reassessing retinal pigment epithelial ketogenesis: Enzymatic assays for ketone body levels provide inaccurate results.

The retinal pigment epithelium (RPE) is omnivorous and can utilize a wide range of substrates for oxidative phosphorylation. Certain tissues with high mitochondrial metabolic load are capable of ketogenesis, a biochemical pathway that consolidates acetyl-CoA into ketone bodies. Earlier work demonstrated that the RPE expresses the rate-limiting enzyme for ketogenesis, 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), and that the RPE indeed produces ketone bodies, including beta-hydroxybutyrate (ß-HB). Prior work, based on detecting ß-HB via enzymatic assays, suggested that differentiated cultures of primary RPE preferentially export ß-HB across the apical membrane. Here, we compare the accuracy of measuring ß-HB by enzymatic assay kits to mass spectrometry analysis. We found that commercial kits lack the sensitivity to accurately measure the levels of ß-HB in RPE cultures and are prone to artifact. Using mass spectrometry, we found that while RPE cultures secrete ß-HB, they do so equally to both apical and basal sides. We also find RPE is capable of consuming ß-HB as levels rise. Using isotopically labeled glucose, amino acid, and fatty acid tracers, we found that carbons from both fatty acids and ketogenic amino acids, but not from glucose, produce ß-HB. Altogether, we substantiate ß-HB secretion in RPE but find that the secretion is equal apically and basally, RPE ß-HB can derive from ketogenic amino acids or fatty acids, and accurate ß-HB assessment requires mass spectrometric analysis.

Rising Inpatient Utilization and Costs of Cannabis Hyperemesis Syndrome Hospitalizations in Massachusetts After Cannabis Legalization.

GOALS: We described the demographics, inpatient utilization, and cost of services among patients hospitalized for putative cannabinoid hyperemesis syndrome (CHS) predating and postdating cannabis legalization in Massachusetts. BACKGROUND: As the recreational use of cannabis has been widely legalized nationally, the resulting shifts in clinical presentation, health care utilization, and estimated costs of CHS hospitalizations remain unclear in the postlegalization era. STUDY: We performed a retrospective cohort study among patients admitted to a large urban hospital between 2012 and 2021, before and after the date of cannabis legalization in Massachusetts (Dec 15, 2016). We examined the demographic and clinical characteristics of patients admitted for putative CHS, the utilization of hospital services, and estimated inpatient costs pre and postlegalization. RESULTS: We identified a significant increase in putative CHS hospitalizations pre and post-cannabis legalization in Massachusetts (0.1% vs 0.02% of total admissions per time period, P < 0.05). Across 72 CHS hospitalizations, patient demographics were similar pre and postlegalization. Hospital resource utilization increased postlegalization, with increased length of stay (3 d vs 1 d, P < 0.005), and need for antiemetics ( P < 0.05). Multivariate linear regression confirmed that postlegalization admissions were independently associated with increased length of stay ( Β = 5.35, P < 0.05). The mean cost of hospitalization was significantly higher postlegalization ($18,714 vs $7460, P < 0.0005), even after adjusting for medical inflation ($18,714 vs $8520, P < 0.001) with intravenous fluid administration and endoscopy costs increased ( P < 0.05). On multivariate linear regression, hospitalization for putative CHS during postlegalization predicted increased costs ( Β = 10,131.25, P < 0.05). CONCLUSIONS: In the postlegalization era of cannabis in Massachusetts, we found increased putative CHS hospitalizations, with a concomitant increased length of hospital stay and total cost per hospitalization. As cannabis use increases, the recognition and costs of its deleterious effects are necessary to incorporate into future clinical practice strategies and health policy.

Rethinking Oncologic Facial Nerve Reconstruction in the Acute Phase Through Classification of the Level of Injury.

Early facial nerve reconstruction should be offered in every patient with oncological resections of the facial nerve due to the debilitating functional and psychosocial consequences of facial nerve palsy. Oncologic pathology or oncologic resection accounts for the second most common cause of facial nerve palsy. In the case of these acute injuries, selecting an adequate method for reconstruction to optimize functional and psychosocial well-being is paramount. Authors advocate consideration of the level of injury as a framework for approaching the viable options of reconstruction systematically. Authors breakdown oncologic injuries to the facial nerve in three levels in relation to their nerve reconstruction methods and strategies: Level I (intracranial to intratemporal), Level II (intratemporal to extratemporal and intraparotid), and Level III (extratemporal and extraparotid). Clinical features, common clinical scenarios, donor nerves available, recipient nerve, and reconstruction priorities will be present at each level. Additionally, examples of clinical cases will be shared to illustrate the utility of framing acute facial nerve injuries within injury levels. Selecting donor nerves is critical in successful facial nerve reconstruction in oncological patients. Usually, a combination of facial and nonfacial donor nerves (hybrid) is necessary to achieve maximal reinnervation of the mimetic muscles. Our proposed classification of three levels of facial nerve injuries provides a selection guide, which prioritizes methods for function nerve reconstruction in relation of the injury level in oncologic patients while prioritizing functional outcomes.

Detection of Transgene Location in the CYP2A13/2B6/2F1-transgenic Mouse Model using Optical Genome Mapping Technology.

Most transgenic mouse models are generated through random integration of the transgene. The location of the transgene provides valuable information for assessing potential effects of the transgenesis on the host and for designing genotyping protocols that can amplify across the integration site, but it is challenging to identify. Here, we report the successful utility of optical genome mapping technology to identify the transgene insertion site in a CYP2A13/2B6/2F1-transgenic mouse model, which produces three human cytochrome P450 (P450) enzymes (CYP2A13, CYP2B6, and CYP2F1) that are encoded by neighboring genes on human chromosome 19. These enzymes metabolize many drugs, respiratory toxicants, and chemical carcinogens. Initial efforts to identify candidate insertion sites by whole genome sequencing was unsuccessful, apparently because the transgene is located in a region of the mouse genome that contains highly repetitive sequences. Subsequent utility of the optical genome mapping approach, which compares genome-wide marker distribution between the transgenic mouse genome and a reference mouse (GRCm38) or human (GRCh38) genome, localized the insertion site to mouse chromosome 14, between two marker positions at 4451324 base pair and 4485032 base pair. A transgene-mouse genome junction sequence was further identified through long-polymerase chain reaction amplification and DNA sequencing at GRCm38 Chr.14:4484726. The transgene insertion (∼2.4 megabase pair) contained 5-7 copies of the human transgenes, which replaced a 26.9-33.4 kilobase pair mouse genomic region, including exons 1-4 of Gm3182, a predicted and highly redundant gene. Finally, the sequencing results enabled the design of a new genotyping protocol that can distinguish between hemizygous and homozygous CYP2A13/2B6/2F1-transgenic mice. SIGNIFICANCE STATEMENT: This study characterizes the genomic structure of, and provides a new genotyping method for, a transgenic mouse model that expresses three human P450 enzymes, CYP2A13, CYP2B6, and CYP2F1, that are important in xenobiotic metabolism and toxicity. The demonstrated success in applying the optical genome mapping technology for identification of transgene insertion sites should encourage others to do the same for other transgenic models generated through random integration, including most of the currently available human P450 transgenic mouse models.

Glucose uptake by GLUT1 in photoreceptors is essential for outer segment renewal and rod photoreceptor survival.

Photoreceptors consume glucose supplied by the choriocapillaris to support phototransduction and outer segment (OS) renewal. Reduced glucose supply underlies photoreceptor cell death in inherited retinal degeneration and age-related retinal disease. We have previously shown that restricting glucose transport into the outer retina by conditional deletion of Slc2a1 encoding GLUT1 resulted in photoreceptor loss and impaired OS renewal. However, retinal neurons, glia, and the retinal pigment epithelium play specialized, synergistic roles in metabolite supply and exchange, and the cell-specific map of glucose uptake and utilization in the retina is incomplete. In these studies, we conditionally deleted Slc2a1 in a pan-retinal or rod-specific manner to better understand how glucose is utilized in the retina. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic deletion of Slc2a1 from retinal neurons and Müller glia results in reduced OS growth and progressive rod but not cone photoreceptor cell death. Rhodopsin levels were severely decreased even at postnatal day 20 when OS length was relatively normal. Arrestin levels were not changed suggesting that glucose uptake is required to synthesize membrane glycoproteins. Rod-specific deletion of Slc2a1 resulted in similar changes in OS length and rod photoreceptor cell death. These studies demonstrate that glucose is an essential carbon source for rod photoreceptor cell OS maintenance and viability.

The Impact of Race and Sex on the Clinical Outcomes of Homeless Patients With Alcoholic Liver Disease: Propensity Score Matched Analysis of US Hospitals.

BACKGROUND: Among patients with alcoholic liver disease (ALD), homelessness poses significant medical and psychosocial risks; however, less is known about the effects of race and sex on the hospital outcomes of admitted homeless patients with ALD. METHODS: The National Inpatient Sample database from 2012 to 2017 was used to isolate homeless patients with ALD, and the cohort was further stratified by race and sex for comparisons. Propensity score matching was utilized to minimize covariate confounding. The primary endpoints of this study include mortality, hospital length of stay, and hospital costs; secondary endpoints included the incidence of liver complications. RESULTS: There were 3972 females/males postmatch, as well as 2224 Blacks/Whites and 4575 Hispanics/Whites postmatch. In multivariate, there were no significant differences observed in mortality rate, length of stay, and costs between sexes. Comparing liver outcomes, females had a higher incidence of hepatic encephalopathy [adjusted odds ratio (aOR) 1.02, 95% CI: 1.01-1.04, P<0.001]. In comparing Blacks versus Whites, Black patients had higher hospitalization costs (aOR 1.13, 95% CI: 1.03-1.24, P=0.01); however, there were no significant differences in mortality, length of stay, or liver complications. In comparing Hispanics versus Whites, Hispanic patients had longer length of hospital stay (aOR 1.12, 95% CI: 1.06-1.19, P<0.001), greater costs (aOR 1.15, 95% CI: 1.09-1.22, P<0.001), as well as higher prevalence of liver complications including varices (aOR 1.04, 95% CI: 1.02-1.06, P<0.001), hepatic encephalopathy (aOR 1.03, 95% CI: 1.02-1.04, P<0.001), and hepatorenal syndrome (aOR 1.01, 95% CI 1.00-1.01, P=0.03). However, there was no difference in mortality between White and Hispanic patients. CONCLUSIONS: Black and Hispanic ALD patients experiencing homelessness were found to incur higher hospital charges; furthermore, Hispanic patients also had greater length of stay and higher incidence of liver-related complications compared with White counterparts.

TMEM67, TMEM237, and Embigin in Complex With Monocarboxylate Transporter MCT1 Are Unique Components of the Photoreceptor Outer Segment Plasma Membrane.

The outer segment (OS) organelle of vertebrate photoreceptors is a highly specialized cilium evolved to capture light and initiate light response. The plasma membrane which envelopes the OS plays vital and diverse roles in supporting photoreceptor function and health. However, little is known about the identity of its protein constituents, as this membrane cannot be purified to homogeneity. In this study, we used the technique of protein correlation profiling to identify unique OS plasma membrane proteins. To achieve this, we used label-free quantitative MS to compare relative protein abundances in an enriched preparation of the OS plasma membrane with a preparation of total OS membranes. We have found that only five proteins were enriched at the same level as previously validated OS plasma membrane markers. Two of these proteins, TMEM67 and TMEM237, had not been previously assigned to this membrane, and one, embigin, had not been identified in photoreceptors. We further showed that embigin associates with monocarboxylate transporter MCT1 in the OS plasma membrane, facilitating lactate transport through this cellular compartment.

Selective ansa cervicalis nerve transfer to the marginal mandibular nerve for lower lip reanimation: An anatomical study in cadavers and a case report.

BACKGROUND: Donor nerve options for lower lip reanimation are limited in patients undergoing oncological resection of the facial nerve. The ansa cervicalis nerve (ACN) is an advantageously situated donor with great potential but has not been examined in detail. In the current study, the anatomical technical feasibility of selective ACN to marginal mandibular nerve (MMN) transfer for restoration of lower lip tone and symmetry was explored. A clinical case is presented. METHODS: Dissections were conducted in 21 hemifaces in non-embalmed human cadavers. The maximal harvestable length of ACN was measured and transfer to MMN was simulated. A 28-year-old male underwent ACN-MMN transfer after parotidectomy (carcinoma) and was evaluated 12 months post-operatively (modified Terzis' Lower Lip Grading Scale [25 observers] and photogrammetry). RESULTS: The harvestable length of ACN was 100 ± 12 mm. A clinically significant anatomical variant ("short ansa") was present in 33% of cases (length: 37 ± 12 mm). Tensionless coaptation was possible in all cases only when using a modification of the surgical technique in "short ansa" cases (using an infrahyoid muscle nerve branch as an extension). The post-operative course of the clinical case was uneventful without complications, with improvement in tone, symmetry, and function at the lower lip at 12-month post-operative follow-up. CONCLUSIONS: Selective ACN-MMN nerve transfer is anatomically feasible in facial paralysis following oncological ablative procedures. It allows direct nerve coaptation without significant donor site morbidity. The clinical case showed good outcomes 12 months post-operatively. A strategy when encountering the "short ansa" anatomical variant in clinical cases is proposed.

Imaging Modalities for Evaluating Lymphedema.

Lymphedema is a progressive condition. Its therapy aims to reduce edema, prevent its progression, and provide psychosocial aid. Nonsurgical treatment in advanced stages is mostly insufficient. Therefore-in many cases-surgical procedures, such as to restore lymph flow or excise lymphedema tissues, are the only ways to improve patients' quality of life. Imaging modalities: Lymphoscintigraphy (LS), near-infrared fluorescent (NIRF) imaging-also termed indocyanine green (ICG) lymphography (ICG-L)-ultrasonography (US), magnetic resonance lymphangiography (MRL), computed tomography (CT), photoacoustic imaging (PAI), and optical coherence tomography (OCT) are standardized techniques, which can be utilized in lymphedema diagnosis, staging, treatment, and follow-up. Conclusions: The combined use of these imaging modalities and self-assessment questionnaires deliver objective parameters for choosing the most suitable surgical therapy and achieving the best possible postoperative outcome.

The deubiquitinating enzyme USP7 regulates the transcription factor Nrf1 by modulating its stability in response to toxic metal exposure.

The nuclear factor E2-related factor 1 (Nrf1) transcription factor performs a critical role in regulating cellular homeostasis as part of the cellular stress response and drives the expression of antioxidants and detoxification enzymes among many other functions. Ubiquitination plays an important role in controlling the abundance and thus nuclear accumulation of Nrf1 proteins, but the regulatory enzymes that act on Nrf1 are not fully defined. Here, we identified ubiquitin specific protease 7 (USP7), a deubiquitinating enzyme, as a novel regulator of Nrf1 activity. We found that USP7 interacts with Nrf1a and TCF11-the two long protein isoforms of Nrf1. Expression of wildtype USP7, but not its catalytically defective mutant, resulted in decreased ubiquitination of TCF11 and Nrf1a, leading to their increased stability and increased transactivation of reporter gene expression by TCF11 and Nrf1a. In contrast, knockdown or pharmacologic inhibition of USP7 dramatically increased ubiquitination of TCF11 and Nrf1a and reduction of their steady state levels. Loss of USP7 function attenuated the induction of Nrf1 protein expression in response to treatment with arsenic and other toxic metals, and inhibition of USP7 activity significantly sensitized cells to arsenic treatment. Collectively, these findings suggest that USP7 may act to modulate abundance of Nrf1 protein to induce gene expression in response to toxic metal exposure.

The clinical impact of frailty on the postoperative outcomes of patients undergoing gastrectomy for gastric cancer: a propensity-score matched database study.

BACKGROUND: Frailty aggregates a composite of geriatric and elderly features that is classified into a singular syndrome; literature thus far has proven its influence over postoperative outcomes. In this study, we evaluate the effects of frailty following gastrectomy for gastric cancer. METHODS: 2011-2017 National Inpatient Sample was used to isolate patients with gastric cancer undergoing gastrectomy; from this, the Johns Hopkins ACG frailty criteria were applied to segregate frailty-present and absent populations. The case-controls were matched using propensity-score matching and compared to various endpoints. RESULTS: Post match, there were 1171 with and without frailty who were undergoing gastrectomy for gastric cancer. Those with frailty had higher mortality (6.83 vs 3.50% p < 0.001, OR 2.02 95% CI 1.37-2.97), length of stay (16.7 vs 12.0d; p < 0.001), and costs ($191,418 vs $131,367; p < 0.001); frail patients also had higher rates of complications including wound complications (3.42 vs 0.94% p < 0.001, OR 3.73 95% CI 1.90-7.31), infection (5.98 vs 3.67% p = 0.012, OR 1.67 95% CI 1.13-2.46), and respiratory failure (6.32 vs 3.84% p = 0.0084, OR 1.69 95% CI 1.15-2.47). In multivariate, those with frailty had higher mortality (p < 0.001, aOR 2.04 95% CI 1.38-3.01), length of stay (p < 0.001, aOR 1.40 95% CI 1.37-1.43), and costs (p < 0.001, aOR 1.46 95% CI 1.46-1.46). CONCLUSION: This study finding demonstrates the presence of frailty is an independent risk factor of adverse outcomes following gastrectomy; as such, it is important that these high-risk patients are stratified preoperatively and provided risk-averting procedures to alleviate their frailty-defining features.

Clinical frailty is a risk factor of adverse outcomes in patients with esophageal cancer undergoing esophagectomy: analysis of 2011-2017 US hospitals.

Frailty is an aggregate of medical and geriatric conditions that affect elderly and vulnerable patients; as frailty is known to affect postoperative outcomes, we evaluate the effects of frailty in patients undergoing esophageal resection surgery for esophageal cancer. 2011-2017 National Inpatient Sample was used to isolate younger (18 to <65) and older (65 or greater) patients undergoing esophagectomy for esophageal cancer, substratified using frailty (defined by Johns-Hopkins ACG frailty indicator) into frail patients and non-frail controls; the controls were 1:1 matched with frail patients using propensity score. Endpoints included mortality, length of stay (LOS), costs, discharge disposition, and postsurgical complications. Following the match, there were 363 and equal number controls in younger cohort; 383 and equal number controls in older cohort. For younger cohort, frail patients had higher mortality (odds ratio [OR] 3.14 95% confidence interval [CI] 1.39-7.09), LOS (20.5 vs. 13.6 days), costs ($320,074 vs. $190,235) and were likely to be discharged to skilled nursing facilities; however, there was no difference in postsurgical complications. In multivariate, frail patients had higher mortality (aOR 3.00 95%CI 1.29-6.99). In older cohort, frail patients had higher mortality (OR 1.96 95%CI 1.07-3.60), LOS (19.9 vs. 14.3 days), costs ($301,335 vs. $206,648) and were more likely to be discharged to short-term hospitals or skilled nursing facilities; the frail patients were more likely to suffer postsurgical respiratory failure (OR 2.03 95%CI 1.31-3.15). In multivariate, frail patients had higher mortality (aOR 1.93 95%CI 1.04-3.58). Clinical frailty adversely affects both younger and older patients undergoing esophagectomy for esophageal cancer.

The clinical impact of frailty on the postoperative outcomes of patients undergoing appendectomy: propensity score-matched analysis of 2011-2017 US hospitals.

BACKGROUND: The presence of clinical frailty can pose an escalated risk toward surgical outcomes including in cases that involve minimally invasive procedures. Given this premise, we evaluate the effects of frailty on post-appendectomy outcomes using a national in-hospital registry. METHODS: 2011-2017 National Inpatient Sample was used to isolate inpatient appendectomy cases; the population as stratified using Johns Hopkins ACG clinical frailty, expressed as either binary or ternary (prefrailty, frailty, and without frailty) indicators. The controls were matched to frailty-present groups using propensity score matching and compared to various endpoints, including mortality, length of stay (LOS), hospitalization costs, and postoperative complications. RESULTS: Post-match, there were 11,758 with and without frailty per binary; and 1236 frail, 10,522 pre-frail with respective equal number controls per ternary indicator. Using binary term, frail patients had higher mortality (4.22 vs 1.49% OR 2.92 95%CI 2.45-3.47), LOS (14.3 vs 5.35d p < 0.001), and costs ($160,700 vs $64,141 p < 0.001). In multivariate, frail patients had higher mortality (aOR 2.77 95%CI 2.32-3.31), as well as higher rates of postoperative complications. Using ternary term, frail patients had higher mortality (5.02 vs 2.27% OR 2.28 95%CI 1.45-3.59), LOS (18.9 vs 5.66 day p < 0.001) and costs ($200,517 vs $66,193 p < 0.001). In multivariate, frail patients had higher mortality (aOR 2.16 95%CI 1.35-3.43) and complications. Those with pre-frailty had higher mortality (4.12 vs 1.47% OR 2.88 95%CI 2.39-3.46), LOS (13.8 vs 5.34 day p < 0.001) and costs ($156,022 vs $63,772 p < 0.001). In multivariate, pre-frailty patients had higher mortality (aOR 2.79 95%CI 2.31-3.37) and complications. CONCLUSIONS: Frailty and prefrailty (using the ternary indicator) are associated with increased postoperative mortality and complication in patients who undergo appendectomy; given this finding, it is imperative that these vulnerable patients are identified early in the preoperative phase and are provided risk-modifying measures to ameliorate risks and optimize outcomes.

Long-term Use of Ultrasound for Locating Optimal LVA Sites: A Descriptive Data Analysis.

BACKGROUND: Preoperative mapping of lymphatic vessels for lymphovenous anastomosis (LVA) surgery is frequently performed by indocyanine green (ICG) lymphography solely; however, other imaging modalities, such as ultrasound (US), might be more efficient, particularly for Caucasian patients. We present our preoperative assessment protocol, experience, and approach of using US for locating optimal LVA sites. METHODS: Fifty-six (16 males) lymphedema patients who underwent LVA surgery were included in this study, 5 of whom received two LVA operations. In total, 61 LVA procedures with 233 dissected lymphatic vessels were evaluated. Preoperative US was performed by the author S.M. 2 days before intraoperative ICG lymphography. Fluid-predominant lymphedema regions were scanned more profoundly. Skin incisions followed preoperative US and ICG lymphography markings. Detection of lymphatic vessels was compared between ICG lymphography and the US by using the intraoperative verification under the microscope with 20 to 50x magnification as the reference standard. RESULTS: Among the dissected lymphatic vessels, 83.3% could be localized by US, and 70% were detectable exclusively by it. In all, 7.2% of US-detected lymphatic vessels could not be found and verified intraoperatively. Among the lymphatic vessels found by US, only 16% were apparent with ICG before skin incision. In total, 23.2% of the dissected lymphatic vessels could be visualized with ICG lymphography preoperatively. Only 9.9% of the lymphatic vessels could be found by ICG alone. CONCLUSION: High-frequency US mapping accurately finds functional lymphatic vessels and matching veins. It locates fluid-predominant regions for targeted LVA surgeries. It reveals 3.6 times as many lymphatic vessels as ICG lymphography. In our practice, it has an integral role in planning LVA procedures.

Role of monocarboxylate transporters in regulating metabolic homeostasis in the outer retina: Insight gained from cell-specific Bsg deletion.

The neural retina metabolizes glucose through aerobic glycolysis generating large amounts of lactate. Lactate flux into and out of cells is regulated by proton-coupled monocarboxylate transporters (MCTs), which are encoded by members of the Slc16a family. MCT1, MCT3, and MCT4 are expressed in the retina and require association with the accessory protein basigin, encoded by Bsg, for maturation and trafficking to the plasma membrane. Bsg-/- mice have severely reduced electroretinograms (ERGs) and progressive photoreceptor degeneration, which is presumed to be driven by metabolic dysfunction resulting from loss of MCTs. To understand the basis of the Bsg-/- phenotype, we generated mice with conditional deletion of Bsg in rods (RodΔBsg), cones (Cone∆Bsg), or retinal pigment epithelial cells (RPEΔBsg). RodΔBsg mice showed a progressive loss of photoreceptors, while ConeΔBsg mice did not display a degenerative phenotype. The RPEΔBsg mice developed a distinct phenotype characterized by severely reduced ERG responses as early as 4 weeks of age. The loss of lactate transporters from the RPE most closely resembled the phenotype of the Bsg-/- mouse, suggesting that the regulation of lactate levels in the RPE and the subretinal space is essential for the viability and function of photoreceptors.

The clinical impact of chronic liver disease in patients undergoing transcatheter and surgical aortic valve replacement: Systematic analysis of the 2011-2017 US hospital database.

OBJECTIVES: In this study, we use a national database to evaluate post-transcatheter (TAVR)/surgical aortic valve replacement (SAVR) outcomes stratified using chronic liver disease (CLD). BACKGROUND: In patients undergoing TAVR and SAVR, the surgical risks should be optimized; this includes evaluating hepatic diseases that may pose an operative risk. METHODS: 2011-2017 National Inpatient Sample was used to select in-hospital TAVR and SAVR cases, which were stratified according to CLD (cirrhosis, hepatitis B/C, alcoholic/fatty/nonspecific liver disease). The cases-controls were matched using propensity score matching and compared with various endpoints. RESULT: After matching for demographics and comorbidities, for TAVR, 606 and 1818 were with or without CLD; for SAVR, 1353 and 4059 were with and without CLD. In TAVR, there was no differences in mortality (2.81% vs. 2.75% OR 1.02 95% CI 0.58-1.78) or length of stay (6.29 vs. 6.44d p = 0.29), and CLD-present patients had marginally increased costs ($228,415 vs. $226,682 p = 0.048). There were no differences in complications. In multivariate, there was no difference in mortality (aOR 1.02 95% CI 0.58-1.79). In SAVR, CLD patients had higher mortality (7.98% vs. 3.23% OR 2.60 95% CI 2.00-3.38), length of stay (13.3 vs. 11.3 days p < 0.001), and costs ($273,487 vs. $238,097 p < 0.001). CLD patients also had increased respiratory failure (9.02% vs. 7.19% OR 1.28 95% CI 1.03-1.59) and bleeding (8.43% vs. 6.33% OR 1.36 95% CI 1.08-1.71). In multivariate, CLD had higher mortality (aOR 2.60 95% CI 2.00-3.38). CONCLUSION: CLD is associated with higher mortality and complications in patients undergoing SAVR; however, no correlation was found in patients undergoing TAVR.

Anatomical Features in Lower-Lip Depressor Muscles for Optimization of Myectomies in Marginal Mandibular Nerve Palsy.

INTRODUCTION: Myectomies of the lower-lip depressor muscles, with the aim to improve facial balance in unilateral facial paralysis, have unexplained high recurrence rates. A potential explanation is that these recurrences are due to inadequate resection through the muscle width, leaving lateral muscle fibers intact. AIM: Revisit the anatomy of the lower-lip depressor muscles and suggest an optimization of the surgical technique. Perform a literature review to identify recurrence rates and surgical technique of the procedure. MATERIALS AND METHODS: Ten fresh hemifaces were dissected. The following measurements of depressor labii inferioris and depressor anguli oris were made: the widths of the muscles, the distance from the mandibular midline to the lateral borders of the muscles, and the intraoral distance from the lateral canine to the lateral border of depressor anguli oris. A literature review was performed. RESULTS: The width of depressor labii inferioris was 20 ±â€Š4 mm and depressor anguli oris 14 ±â€Š3 mm. The distance from the midline to the lateral border of depressor labii inferioris was 32 ±â€Š4 mm and 54 ±â€Š4 mm for depressor anguli oris. The literature review revealed a mean recurrence rate of 21%. DISCUSSION: A potential optimization of the surgical technique in lower-lip depressor myectomies is to extend the muscle resection laterally. To ensure inclusion of the whole width of the depressor muscles and decrease the recurrence rates of the procedure, the measurements presented in this study should be kept in mind during surgery.

Glucosylceramidase Maintains Influenza Virus Infection by Regulating Endocytosis.

Influenza virus is an RNA virus encapsulated in a lipid bilayer derived from the host cell plasma membrane. Previous studies showed that influenza virus infection depends on cellular lipids, including the sphingolipids sphingomyelin and sphingosine. Here we examined the role of a third sphingolipid, glucosylceramide, in influenza virus infection following clustered regularly interspaced short palindromic repeats with Cas9 (CRISPR-Cas9)-mediated knockout (KO) of its metabolizing enzyme glucosylceramidase (GBA). After confirming GBA knockout of HEK 293 and A549 cells by both Western blotting and lipid mass spectrometry, we observed diminished infection in both KO cell lines by a PR8 (H1N1) green fluorescent protein (GFP) reporter virus. We further showed that the reduction in infection correlated with impaired influenza virus trafficking to late endosomes and hence with fusion and entry. To examine whether GBA is required for other enveloped viruses, we compared the results seen with entry mediated by the glycoproteins of Ebola virus, influenza virus, vesicular stomatitis virus (VSV), and measles virus in GBA knockout cells. Entry inhibition was relatively robust for Ebola virus and influenza virus, modest for VSV, and mild for measles virus, suggesting a greater role for viruses that enter cells by fusing with late endosomes. As the virus studies suggested a general role for GBA along the endocytic pathway, we tested that hypothesis and found that trafficking of epidermal growth factor (EGF) to late endosomes and degradation of its receptor were impaired in GBA knockout cells. Collectively, our findings suggest that GBA is critically important for endocytic trafficking of viruses as well as of cellular cargos, including growth factor receptors. Modulation of glucosylceramide levels may therefore represent a novel accompaniment to strategies to antagonize "late-penetrating" viruses, including influenza virus.IMPORTANCE Influenza virus is the pathogen responsible for the second largest pandemic in human history. A better understanding of how influenza virus enters host cells may lead to the development of more-efficacious therapies against emerging strains of the virus. Here we show that the glycosphingolipid metabolizing enzyme glucosylceramidase is required for optimal influenza virus trafficking to late endosomes and for consequent fusion, entry, and infection. We also provide evidence that promotion of influenza virus entry by glucosylceramidase extends to other endosome-entering viruses and is due to a general requirement for this enzyme, and hence for optimal levels of glucosylceramide, for efficient trafficking of endogenous cargos, such as the epidermal growth factor (EGF) receptor, along the endocytic pathway. This work therefore has implications for the basic process of endocytosis as well as for pathogenic processes, including virus entry and Gaucher disease.

Institutionalization of reconstructive lymphedema surgery in Austria-Single center experience.

BACKGROUND: Lymphedema surgery was not widely known in Austria before the introduction of lymphovenous anastomosis (LVA) and vascularized lymph node transfer (VLNT) in 2014. This study shares the experience and process of establishing and institutionalizing lymphedema surgery service in Austria. METHODS: The purpose of introducing reconstructive lymphedema surgery in Austria was to improve lymphedema patients' quality of life and provide them surgical therapy as an adjuvant treatment to complete decongestive therapy. To initialize reconstructive lymphedema surgery in Austria, LVA and VLNT had to be presented and introduced, in the manner of branding and advertizing a new product. Surgeries were performed with quality control by standardized documentation, pre- and postoperatively. RESULTS: Aligned with branding and marketing, presentations were given externally and internally to share knowledge and experience of lymphedema surgery. Lymphedema surgery service was introduced as a new brand in the medical service in Austria. After several communications with the Austrian Health Insurance Fund and with the final application, LVA and VLNT were listed as novel surgical therapies in its 2020 reimbursement catalog. Since 2014, more than 300 lymphedema patients were consulted, and 102 reconstructive lymphedema surgeries were performed. Circumference reduction of extremities after surgery was between 20% and 43%, postoperatively. CONCLUSION: Acceptance of surgery in lymphedema patients varies among continents, hospitals, and surgeons. Evaluation of the requirement of the surgical setup and insurance conditions for lymphedema surgery is essential to establish lymphedema surgery, providing targeted marketing and branding to spread knowledge of the novel technique and grant patients access to therapeutic treatment of their chronic disease.