Thickened Retinal Nerve Fiber Layer Without Hypermyelination in Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay.

Purpose: To report the retinal findings in a patient with autosomal recessive spastic ataxia of Charlevoix-Saguenay. Methods: A case was evaluated. Results: A 16-year-old male patient with a known diagnosis of autosomal recessive spastic ataxia of Charlevoix-Saguenay was referred for evaluation of retinal hypermyelination given its frequent association with the condition. The patient was asymptomatic with a best-corrected visual acuity of 20/20. Optical coherence tomography of the peripapillary retinal nerve fiber layer (RNFL) showed bilateral thickening in each eye (average thicknesses: 180 µm, right eye; 177 µm, left eye). An examination showed no myelinization of the RNFL. Conclusions: Most studies to date describe RNFL thickening secondary to hypermyelination as a characteristic finding in autosomal recessive spastic ataxia of Charlevoix-Saguenay. This case provides evidence that this thickening may be a result of hypertrophy rather than hypermyelination. Further investigation is needed to define the pathophysiologic cause of RNFL thickening in autosomal recessive spastic ataxia of Charlevoix-Saguenay.

Targeting Cholesterol Biosynthesis with Statins Synergizes with AKT Inhibitors in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is responsible for a disproportionate number of breast cancer patient deaths due to extensive molecular heterogeneity, high recurrence rates, and lack of targeted therapies. Dysregulation of the phosphoinositide 3-kinase (PI3K)/AKT pathway occurs in approximately 50% of TNBC patients. Here, we performed a genome-wide CRISPR/Cas9 screen with PI3Kα and AKT inhibitors to find targetable synthetic lethalities in TNBC. Cholesterol homeostasis was identified as a collateral vulnerability with AKT inhibition. Disruption of cholesterol homeostasis with pitavastatin synergized with AKT inhibition to induce TNBC cytotoxicity in vitro in mouse TNBC xenografts and in patient-derived estrogen receptor (ER)-negative breast cancer organoids. Neither ER-positive breast cancer cell lines nor ER-positive organoids were sensitive to combined AKT inhibitor and pitavastatin. Mechanistically, TNBC cells showed impaired sterol regulatory element-binding protein 2 (SREBP-2) activation in response to single-agent or combination treatment with AKT inhibitor and pitavastatin, which was rescued by inhibition of the cholesterol-trafficking protein Niemann-Pick C1 (NPC1). NPC1 loss caused lysosomal cholesterol accumulation, decreased endoplasmic reticulum cholesterol levels, and promoted SREBP-2 activation. Taken together, these data identify a TNBC-specific vulnerability to the combination of AKT inhibitors and pitavastatin mediated by dysregulated cholesterol trafficking. These findings support combining AKT inhibitors with pitavastatin as a therapeutic modality in TNBC. Significance: Two FDA-approved compounds, AKT inhibitors and pitavastatin, synergize to induce cell death in triple-negative breast cancer, motivating evaluation of the efficacy of this combination in clinical trials.

Rapid iPSC inclusionopathy models shed light on formation, consequence, and molecular subtype of α-synuclein inclusions.

The heterogeneity of protein-rich inclusions and its significance in neurodegeneration is poorly understood. Standard patient-derived iPSC models develop inclusions neither reproducibly nor in a reasonable time frame. Here, we developed screenable iPSC "inclusionopathy" models utilizing piggyBac or targeted transgenes to rapidly induce CNS cells that express aggregation-prone proteins at brain-like levels. Inclusions and their effects on cell survival were trackable at single-inclusion resolution. Exemplar cortical neuron α-synuclein inclusionopathy models were engineered through transgenic expression of α-synuclein mutant forms or exogenous seeding with fibrils. We identified multiple inclusion classes, including neuroprotective p62-positive inclusions versus dynamic and neurotoxic lipid-rich inclusions, both identified in patient brains. Fusion events between these inclusion subtypes altered neuronal survival. Proteome-scale α-synuclein genetic- and physical-interaction screens pinpointed candidate RNA-processing and actin-cytoskeleton-modulator proteins like RhoA whose sequestration into inclusions could enhance toxicity. These tractable CNS models should prove useful in functional genomic analysis and drug development for proteinopathies.

Synthesis of Radiolabeled [14C]Rimsulfuron and Stable Isotope Labeled Rimsulfuron-[M + 3] to Support Crop Metabolism Studies for Reregistration.

Rimsulfuron is a sulfonylurea herbicide that controls grass and broadleaf weeds in maize, potatoes, fruits, nuts, and other crops. It can also be used as a burndown herbicide to clear invasive weed species along roadsides and other nonagricultural land. Rimsulfuron acts as an acetolactase synthase (ALS) inhibitor, blocking the synthesis of essential amino acids required for plant growth. As is common practice, rimsulfuron has been subject to periodic reviews by regulatory agencies for reregistration since its introduction into the market in the early 1990s. The goal of these reviews is to ensure that the herbicide carries out its intended use without creating adverse side effects to humans and the environment. Since scientific methods are continually evolving and being developed, global regulatory agencies can require additional studies to address data gaps for pesticide renewals. During this reregistration process for rimsulfuron, a new confined rotational crop study was required to address a data gap requested by the European Food Safety Authority (EFSA). Consequently, the corresponding pyridine and pyrimidine radiolabeled [14C]rimsulfuron and [M + 3] stable isotopes of rimsulfuron were synthesized for this study to support the reregistration process.

Proteasomal control of anti-CRISPRs for the regulation of CRISPR/Cas9 activity using Cas9-ACROBAT.

Small molecule-mediated proteasomal degradation of proteins is a powerful tool for synthetic regulation of biological activity. To control Cas9 activity in cells, we engineered an anti-CRISPR protein, AcrIIA4, fused to a degradation (dTAG) or small molecule assisted shutoff (SMASh) tag. Co-expression of the tagged AcrIIA4 along with Cas9 and riboswitch-regulated sgRNAs enables precise tunable control of CRISPR activity by small molecule addition.

Duplicated Copy Number Variant of the Maize 9-Lipoxygenase ZmLOX5 Improves 9,10-KODA-Mediated Resistance to Fall Armyworms.

Extensive genome structure variations, such as copy number variations (CNVs) and presence/absence variations, are the basis for the remarkable genetic diversity of maize; however, the effect of CNVs on maize herbivory defense remains largely underexplored. Here, we report that the naturally occurring duplication of the maize 9-lipoxygenase gene ZmLOX5 leads to increased resistance of maize to herbivory by fall armyworms (FAWs). Previously, we showed that ZmLOX5-derived oxylipins are required for defense against chewing insect herbivores and identified several inbred lines, including Yu796, that contained duplicated CNVs of ZmLOX5, referred to as Yu796-2×LOX5. To test whether introgression of the Yu796-2×LOX5 locus into a herbivore-susceptible B73 background that contains a single ZmLOX5 gene is a feasible approach to increase resistance, we generated a series of near-isogenic lines that contained either two, one, or zero copies of the Yu796-2×LOX5 locus in the B73 background via six backcrosses (BC6). Droplet digital PCR (ddPCR) confirmed the successful introgression of the Yu796-2×LOX5 locus in B73. The resulting B73-2×LOX5 inbred line displayed increased resistance against FAW, associated with increased expression of ZmLOX5, increased wound-induced production of its primary oxylipin product, the α-ketol, 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (9,10-KODA), and the downstream defense hormones regulated by this molecule, 12-oxo-phytodienoic acid (12-OPDA) and abscisic acid (ABA). Surprisingly, wound-induced JA-Ile production was not increased in B73-2×LOX5, resulting from the increased JA catabolism. Furthermore, B73-2×LOX5 displayed reduced water loss in response to drought stress, likely due to increased ABA and 12-OPDA content. Taken together, this study revealed that the duplicated CNV of ZmLOX5 quantitively contributes to maize antiherbivore defense and presents proof-of-concept evidence that the introgression of naturally occurring duplicated CNVs of a defensive gene into productive but susceptible crop varieties is a feasible breeding approach for enhancing plant resistance to herbivory and tolerance to abiotic stress.

Pediatric anesthesia in North America.

BACKGROUND AND OBJECTIVES: This educational review outlines the current landscape of pediatric anesthesia training, care delivery, and challenges across Canada, Barbados, and the United States. DESCRIPTIONS AND CONCLUSIONS: Approximately 5% of Canadian children undergo general anesthesia annually, administered by fellowship-trained pediatric anesthesiologists in children's hospitals, general anesthesiologists in community hospitals, or family practice anesthesiologists in underserved regions. In Canada, the focus is on national-level evaluation and accreditation of pediatric anesthesia fellowship training, addressing challenges arising from workforce shortages, particularly in remote areas. Barbados, a Caribbean nation, lacks dedicated pediatric hospitals but has provided pediatric anesthesia since 1972 through anesthetists with additional training. Challenges in its development, common to low-middle-income countries, include inadequate infrastructure and workforce shortages. Increased awareness of pediatric anesthesia as a sub-specialty could enhance perioperative care for Barbadian children. Pediatric anesthesia encompasses various specialties in the United States, with pediatric anesthesiologists playing a foundational role. Challenges faced include recruitment and retention difficulties, supply-chain shortages, and the proliferation of anesthesia sites, all impacting the delivery of modern, high-quality, and cost-effective patient care. Collaborative efforts at national and organizational levels strive to improve the quality and safety of pediatric anesthesia care in the United States.

Bilateral Optic Nerve Sheath Meningoceles in an Asymptomatic Patient.

This case report discusses a diagnosis of bilateral optic nerve sheath meningoceles in a man aged 82 years with stable visual acuity and asymptomatic bilateral choroidal folds.

A Multi-Site Survey Study on the Association Between the COVID-19 Pandemic and United States Anesthesiology Residents' Mental Health.

BACKGROUND:  At the onset of the coronavirus disease 2019 (COVID-19) pandemic, anesthesiology residency programs were impacted differently due to various factors such as the local severity of COVID-19, exposure to patient suffering, and inability to complete rotations. We sought to investigate the impact of local-level pandemic severity on the well-being of anesthesiology residents. METHODS:  This multi-site study surveyed postgraduate year two residents from 15 United States (US) anesthesiology programs using the Perceived Stress Scale, Mini-Z, Patient Health Questionnaire-9,WHO-5 Well-Being Index,and the Multidimensional Scale of Perceived Social Support before the pandemic (baseline survey) and during the first COVID-19 surge (post survey). RESULTS:  A total of 144 (65%) residents responded to the initial baseline survey; 73 (33%) responded to the post survey, and 49 (22%) completed both surveys. There was not a statistically significant difference in any well-being outcomes of participants between the surveys, nor was there a significant difference based on the severity of COVID-19 impact at the program's hospital. Male participants had higher perceived stress scores (ß = 4.05, 95%CI: 0.42, 7.67, P = 0.03) and lower social support from family (ß = -6.57, 95%CI: -11.64, -1.51, P = 0.01) at the post survey compared to female participants after controlling for baseline scores. Additionally, married participants or those with domestic partners reported higher perceived social support in the post survey (ß = 5.79, 95%CI: -0.65, 12.23, P = 0.03). CONCLUSION:  The local COVID-19 severity at a residency program did not disproportionately impact well-being scores among anesthesiology residents. Those most vulnerable to diminished well-being appeared to be male and single participants. As a result, targeted well-being interventions, including those aiming to increase social support, to higher-risk resident groups may be indicated. Future work is needed to assess the longstanding COVID-19 pandemic impacts on resident well-being.

Cost of pediatric laryngotracheal reconstruction: Differences between single-versus double-stage procedures.

OBJECTIVE: Examine differences in cost between single stage (ss) versus double stage (ds) laryngotracheal reconstruction (LTR) for pediatric subglottic stenosis. STUDY DESIGN: Retrospective chart review of children who underwent ssLTR or dsLTR from 2014 to 2018 at a single institution. METHODS: Costs related to LTR and post-operative care up to one year after tracheostomy decannulation were extrapolated from charges billed to the patient. Charges were obtained from the hospital finance department and the local medical supplies company. Patient demographics including baseline severity of subglottic stenosis and co-morbidities were noted. Variables assessed include duration of hospital admission, number of ancillary procedures, duration of sedation wean, cost of tracheostomy maintenance, and time to tracheostomy decannulation. RESULTS: Fifteen children underwent LTR for subglottic stenosis. D Ten patients underwent ssLTR, while five underwent dsLTR. Grade 3 subglottic stenosis was more prevalent in patients who underwent dsLTR (100%) than ssLTR (50%). The average per-patient hospital charges for ssLTR was $314,383 versus $183,638 for dsLTR. When estimated mean cost of tracheostomy supplies and nursing care until tracheostomy decannulation was included, the mean total charges associated with dsLTR patients was $269,456. Average hospital stay after initial surgery was 22 days for ssLTR versus 6 days for dsLTR. Average time to tracheostomy decannulation for dsLTR was 297 days. Average number of ancillary procedures needed was 3 versus 8 for ssLTR versus dsLTR. CONCLUSION: For pediatric patients with subglottic stenosis, dsLTR may have a lower cost than ssLTR. Although ssLTR has the benefit of immediate decannulation, it is associated with higher patient charges, as well as longer initial hospitalization and sedation. For both patient groups, fees associated with nursing care comprised the majority of charges. Recognizing the factors that contribute to cost differences between ssLTR and dsLTR may be useful when performing cost-benefit analyses and assessing value in health care delivery.

Symbiotic ant traits produce differential host-plant carbon and water dynamics in a multi-species mutualism.

Cooperative interactions may frequently be reinforced by "partner fidelity feedback," in which high- or low-quality partners drive positive feedbacks with high or low benefits for the host, respectively. Benefits of plant-animal mutualisms for plants have been quantified almost universally in terms of growth or reproduction, but these are only two of many sinks to which a host-plant allocates its resources. By investigating how partners to host-plants impact two fundamental plant resources, carbon and water, we can better characterize plant-partner fidelity and understand how plant-partner mutualisms may be modulated by resource dynamics. In Laikipia, Kenya, four ant species compete for Acacia drepanolobium host-plants. These ants differ in multiple traits, from nectar consumption to host-plant protection. Using a 5-year ant removal experiment, we compared carbon fixation, leaf water status, and stem non-structural carbohydrate concentrations for adult ant-plants with and without ant partners. Removal treatments showed that the ants differentially mediate tree carbon and/or water resources. All three ant species known to be aggressive against herbivores were linked to benefits for host-plant resources, but only the two species that defend but do not prune the host, Crematogaster mimosae and Tetraponera penzigi, increased tree carbon fixation. Of these two species, only the nectivore C. mimosae increased tree simple sugars. Crematogaster nigriceps, which defends the tree but also castrates flowers and prunes meristems, was linked only to lower tree water stress approximated by pre-dawn leaf water potential. In contrast to those defensive ants, Crematogaster sjostedti, a poor defender that displaces other ants, was linked to lower tree carbon fixation. Comparing the effects of the four ant species across control trees suggests that differential ant occupancy drives substantial differences in carbon and water supply among host trees. Our results highlight that ant partners can positively or negatively impact carbon and/or water relations for their host-plant, and we discuss the likelihood that carbon- and water-related partner fidelity feedback loops occur across ant-plant mutualisms.

Genetically Confirmed Malignant Hyperthermia in a Six-Week-Old Infant: A Case Report.

A six-week-old 3.9-kg infant presented for microlaryngoscopy and diaphragmatic hernia repair. While positioning for laparoscopy after microlaryngoscopy, the infant developed muscle rigidity, worsening hypercarbia, tachycardia, and early hyperthermia. Sevoflurane was discontinued, and the clinical picture indicating malignant hyperthermia (MH) resolved without dantrolene. Subsequent genetic testing revealed that both the patient and his father carried a mutation in the RYR1 gene that is diagnostic for MH. This is the second youngest genetically confirmed case of MH. This case adds to a limited body of evidence regarding MH presentation and diagnosis in neonates and infants.

Association of low skeletal muscle mass and systemic inflammation with surgical complications and survival after microvascular flap reconstruction in patients with head and neck cancer.

BACKGROUND: Skeletal muscle mass (SMM) and chronic inflammation are associated with postoperative complications and survival. METHODS: Patients with head and neck cancer (HNC) undergoing microvascular free flap reconstruction were included. SMM and neutrophil-to-lymphocyte ratio (NLR) were measured and their association with treatment outcomes analyzed. RESULTS: Five hundred and fifty-four patients were included. Predictors for complications were elevated NLR in all flaps (OR 1.5), low SMM in radial forearm flap (OR 2.0), and elevated NLR combined with low SMM in fibula flap surgery (OR 4.3). Patients with solely elevated NLR were at risk for flap-related complications (OR 3.0), severe complications (OR 2.2), and when combined with low SMM for increased length of hospital stays (LOS) (+3.9 days). In early-stage HNC, low SMM (HR 2.3), and combined elevated NLR with low SMM (HR 2.6) were prognostics for decreased overall survival. CONCLUSIONS: SMM and NLR are predictive for poor outcomes in patients with HNC undergoing microvascular reconstruction.

Septic Arthritis of the Temporomandibular Joint with Intracranial Extension: A Case Report.

Septic arthritis of the temporomandibular joint (TMJ) is rare with few cases reported in the literature. We present a case of septic arthritis of the left TMJ in an 18-year-old man who was initially referred as a suspected TMJ dislocation. He had a 3-day history of pain, trismus and malocclusion with left preauricular swelling and became clinically septic with a positive blood culture containing Fusobacterium necrophorum. Computed tomography revealed left TMJ effusion. A later scan showed evidence of a temporal space collection and development of an intracranial extension in the left middle cranial fossa. The patient underwent needle arthrocentesis and drainage, followed by six weeks of antibiotic therapy following advice from neurosurgery and microbiology. Further imaging revealed resolution of the collection. Few cases have been reported of this unusual diagnosis, and this case demonstrates the importance of close multidisciplinary input in forming an accurate diagnosis and managing appropriately.

Genetic analysis of cancer drivers reveals cohesin and CTCF as suppressors of PD-L1.

Immune evasion is a significant contributor to tumor evolution, and the immunoinhibitory axis PD-1/PD-L1 is a frequent mechanism employed to escape tumor immune surveillance. To identify cancer drivers involved in immune evasion, we performed a CRISPR-Cas9 screen of tumor suppressor genes regulating the basal and interferon (IFN)-inducible cell surface levels of PD-L1. Multiple regulators of PD-L1 were identified, including IRF2, ARID2, KMT2D, and AAMP. We also identified CTCF and the cohesin complex proteins, known regulators of chromatin architecture and transcription, among the most potent negative regulators of PD-L1 cell surface expression. Additionally, loss of the cohesin subunit RAD21 was shown to up-regulate PD-L2 and MHC-I surface expression. PD-L1 and MHC-I suppression by cohesin were shown to be conserved in mammary epithelial and myeloid cells. Comprehensive examination of the transcriptional effect of STAG2 deficiency in epithelial and myeloid cells revealed an activation of strong IFN and NF-κB expression signatures. Inhibition of JAK-STAT or NF-κB pathways did not result in rescue of PD-L1 up-regulation in RAD21-deficient cells, suggesting more complex or combinatorial mechanisms at play. Discovery of the PD-L1 and IFN up-regulation in cohesin-mutant cells expands our understanding of the biology of cohesin-deficient cells as well as molecular regulation of the PD-L1 molecule.

Spatial variability in tree-ring carbon isotope discrimination in response to local drought across the entire loblolly pine natural range.

Considering the temporal responses of carbon isotope discrimination (Δ13C) to local water availability in the spatial analysis of Δ13C is essential for evaluating the contribution of environmental and genetic facets of plant Δ13C. Using tree-ring Δ13C from years with contrasting water availability at 76 locations across the natural range of loblolly pine, we decomposed site-level Δ13C signals to maximum Δ13C in well-watered conditions (Δ13Cmax) and isotopic drought sensitivity (m) as a change in Δ13C per unit change of Palmer's Drought Severity Index (PDSI). Site water status, especially the tree lifetime average PDSI, was the primary factor affecting Δ13Cmax. The strong spatial correlation exhibited by m was related to both genetic and environmental factors. The long-term average water availability during the period relevant to trees as indicated by lifetime average PDSI correlated with Δ13Cmax, suggesting acclimation in tree gas-exchange traits, independent of incident water availability. The positive correlation between lifetime average PDSI and m indicated that loblolly pines were more sensitive to drought at mesic than xeric sites. The m was found to relate to a plant's stomatal control and may be employed as a genetic indicator of efficient water use strategies. Partitioning Δ13C to Δ13Cmax and m provided a new angle for understanding sources of variation in plant Δ13C, with several fundamental and applied implications.

An evaluation of the clinical utility of C-reactive protein and antibiotic use in patients undergoing major head and neck reconstructive surgery with outcome assessment.

PURPOSE: This ambispective observational study aims to evaluate the local utility of peri-operative CRP testing and prophylactic antibiotics in relation to post-operative complications in patients who have undergone major head and neck oncological reconstructive surgery. RESULTS: A total of 79 patients were identified for inclusion; CRP testing was undertaken within the first 3 days postoperatively in 78/79 cases. Results demonstrated no benefit of extended prophylactic antibiotic use in reducing post-operative infection. Forty-two post-operative complications arose. In the prospective arm, CRP did not influence the decision to commence antibiotic therapy for any of the surgical site infections. Age, diabetes, smoking, or high body mass index (BMI) did not appear to affect the incidence of postoperative infection (p > 0.05). There is no evidence that more than 24 h of antibiotic prophylaxis is indicated for patients undergoing head and neck reconstructive surgery. CONCLUSION: Everyone who is involved in peri-operative patient care should be educated regarding the appropriate use of CRP testing, with the implementation of protocols required to standardize CRP testing and prophylactic antibiotic prescription.

Mindful awareness moderates the association between psychological inflexibility and distress variables: A cross-sectional investigation.

OBJECTIVE: Informed by the contextual behavioral science (CBS) model of behavioral health, the present cross-sectional study examined whether mindful awareness moderated the associations between psychological inflexibility and four distress variables. PARTICIPANTS: Cross-sectional data were collected from 402 ethnically diverse undergraduate college students from September 2015 to October 2015. METHODS: Participants competed an online self-report survey. RESULTS: Mindful awareness moderated the associations between psychological inflexibility and distress variables, with stronger associations for somatization and anxiety, and weaker associations for general distress and depression. Specifically, the strength of the positive associations between psychological inflexibility and these distress variables were substantially greater among those low in mindful awareness. CONCLUSION: These findings suggest that a greater degree of mindful awareness may buffer the effects of psychological inflexibility on distress variables, particularly somatization and anxiety. Theoretical and applied implications as well as limitations of the study are discussed.