Mutations that prevent caspase cleavage of RIPK1 cause autoinflammatory disease.

RIPK1 is a key regulator of innate immune signalling pathways. To ensure an optimal inflammatory response, RIPK1 is regulated post-translationally by well-characterized ubiquitylation and phosphorylation events, as well as by caspase-8-mediated cleavage1-7. The physiological relevance of this cleavage event remains unclear, although it is thought to inhibit activation of RIPK3 and necroptosis8. Here we show that the heterozygous missense mutations D324N, D324H and D324Y prevent caspase cleavage of RIPK1 in humans and result in an early-onset periodic fever syndrome and severe intermittent lymphadenopathy-a condition we term 'cleavage-resistant RIPK1-induced autoinflammatory syndrome'. To define the mechanism for this disease, we generated a cleavage-resistant Ripk1D325A mutant mouse strain. Whereas Ripk1-/- mice died postnatally from systemic inflammation, Ripk1D325A/D325A mice died during embryogenesis. Embryonic lethality was completely prevented by the combined loss of Casp8 and Ripk3, but not by loss of Ripk3 or Mlkl alone. Loss of RIPK1 kinase activity also prevented Ripk1D325A/D325A embryonic lethality, although the mice died before weaning from multi-organ inflammation in a RIPK3-dependent manner. Consistently, Ripk1D325A/D325A and Ripk1D325A/+ cells were hypersensitive to RIPK3-dependent TNF-induced apoptosis and necroptosis. Heterozygous Ripk1D325A/+ mice were viable and grossly normal, but were hyper-responsive to inflammatory stimuli in vivo. Our results demonstrate the importance of caspase-mediated RIPK1 cleavage during embryonic development and show that caspase cleavage of RIPK1 not only inhibits necroptosis but also maintains inflammatory homeostasis throughout life.

Genome sequencing detects a balanced pericentric inversion with breakpoints that impact the DMD and upstream region of POU3F4 genes.

We describe a family with two maternal half-brothers both of whom presented with muscular dystrophy, autism spectrum disorder, developmental delay, and sensorineural hearing loss. The elder brother had onset of features at ~3 months of age, followed by clinical confirmation of muscular dystrophy at 3 years. Skeletal biopsy staining at 4.7 years showed an absence of dystrophin protein which prompted extensive molecular testing over 4 years that included gene panels, targeted single-gene assays, arrays, and karyotyping, all of which failed to identify a clinically significant variant in the DMD gene. At 10 years of age, clinical whole-genome sequencing (cWGS) was performed, which revealed a novel hemizygous ~50.7 Mb balanced pericentric inversion on chromosome X that disrupts the DMD gene in both siblings, consistent with the muscular dystrophy phenotype. This inversion also impacts the upstream regulatory region of POU3F4, structural rearrangements which are known to cause hearing loss. The unaffected mother is a heterozygous carrier for the pericentric inversion. This finding illustrates the ability of cWGS to detect a wide breadth of disease-causing genomic variations including large genomic rearrangements.

A Network of Conserved Synthetic Lethal Interactions for Exploration of Precision Cancer Therapy.

An emerging therapeutic strategy for cancer is to induce selective lethality in a tumor by exploiting interactions between its driving mutations and specific drug targets. Here we use a multi-species approach to develop a resource of synthetic lethal interactions relevant to cancer therapy. First, we screen in yeast ∼169,000 potential interactions among orthologs of human tumor suppressor genes (TSG) and genes encoding drug targets across multiple genotoxic environments. Guided by the strongest signal, we evaluate thousands of TSG-drug combinations in HeLa cells, resulting in networks of conserved synthetic lethal interactions. Analysis of these networks reveals that interaction stability across environments and shared gene function increase the likelihood of observing an interaction in human cancer cells. Using these rules, we prioritize ∼10(5) human TSG-drug combinations for future follow-up. We validate interactions based on cell and/or patient survival, including topoisomerases with RAD17 and checkpoint kinases with BLM.

Methylome-wide Analysis of Chronic HIV Infection Reveals Five-Year Increase in Biological Age and Epigenetic Targeting of HLA.

HIV-infected individuals are living longer on antiretroviral therapy, but many patients display signs that in some ways resemble premature aging. To investigate and quantify the impact of chronic HIV infection on aging, we report a global analysis of the whole-blood DNA methylomes of 137 HIV+ individuals under sustained therapy along with 44 matched HIV- individuals. First, we develop and validate epigenetic models of aging that are independent of blood cell composition. Using these models, we find that both chronic and recent HIV infection lead to an average aging advancement of 4.9 years, increasing expected mortality risk by 19%. In addition, sustained infection results in global deregulation of the methylome across >80,000 CpGs and specific hypomethylation of the region encoding the human leukocyte antigen locus (HLA). We find that decreased HLA methylation is predictive of lower CD4 / CD8 T cell ratio, linking molecular aging, epigenetic regulation, and disease progression.

Is Insurance Payer Associated With Hospital Admission of Emergency Department Patients With Mandible Fractures?

BACKGROUND: There is a lack of consensus on the optimal triage pathway for emergency department (ED) patients with mandibular fractures. It remains unclear if patient insurance payers predict hospital admission given potentially competing logistical and health system incentives. PURPOSE: To generate nationally representative estimates of the frequency of hospital admission and its association with primary insurance payers for ED patients with mandible fractures. METHODS: This retrospective cohort study used the 2018 Nationwide Emergency Department Sample, the largest all-payer database in the United States, to identify patients with mandible fractures. The database includes a stratified sample with discharge weights to generate nationally representative estimates. Patients with other facial fractures and/or concomitant injuries that independently warranted admission were excluded. PREDICTOR: The primary predictor variable was primary payer (public, private, self-pay, and other/no charge). OUTCOME VARIABLE: The primary outcome variable was hospital admission (yes/no). COVARIATES: Covariates included patient-, medical/injury-, and hospital-related variables. ANALYSES: Descriptive statistics, along with bivariate and multivariate logistic regression with Bonferroni correction, were used to produce national estimates and identify predictors of admission. P < .01 was considered significant. RESULTS: The cohort included 27,238 weighted encounters involving isolated mandible fractures, of which 5,345(20%) were admitted. The payers for admitted patients were 46% public, 25% private, 22% self-pay, and 7% no charge/other. In bivariate analyses, public insurance was associated with a higher likelihood of admission than private insurance (RR 1.24, 95% CI 1.06 to 1.45), though there was no association in the multivariate model (OR 1.03, 95% CI 0.83 to 1.28). In multivariate analysis, higher Charlson Comorbidity Index (OR 1.32, 95% CI 1.18 to 1.48), alcohol-related disorder (OR 3.47, 95% CI 2.74 to 4.39), substance-related disorder (OR 1.43, 95% CI 1.20 to 1.71), and more mandible fractures (OR 3.08, 95% CI 2.65 to 3.59) were associated with admission. Compared to body fractures, subcondylar (OR 3.83, 95% CI 2.39 to 6.14), angle (OR 3.53, 95% CI 2.84 to 6.09), and symphysis (OR 4.14, 95% CI 2.84 to 6.09) fractures had higher odds of admission. Finally, level I (OR 4.11, 95% CI 2.41 to 6.98) and level II (OR 3.16, 95% CI 1.85 to 5.39) trauma centers had higher odds of admission. CONCLUSIONS: In 2018, 20% of ED patients with isolated mandible fractures were admitted. Several patient and hospital characteristics were predictors of admission. Insurance status was not associated with admission.

Using the technology acceptance model to assess clinician perceptions and experiences with a rheumatoid arthritis outcomes dashboard: qualitative study.

BACKGROUND: Improving shared decision-making using a treat-to-target approach, including the use of clinical outcome measures, is important to providing high quality care for rheumatoid arthritis (RA). We developed an Electronic Health Record (EHR) integrated, patient-facing sidecar dashboard application that displays RA outcomes, medications, and lab results for use during clinical visits ("RA PRO dashboard"). The purpose of this study was to assess clinician perceptions and experiences using the dashboard in a university rheumatology clinic. METHODS: We conducted focus group (FG) discussions with clinicians who had access to the dashboard as part of a randomized, stepped-wedge pragmatic trial. FGs explored clinician perceptions towards the usability, acceptability, and usefulness of the dashboard. FG data were analyzed thematically using deductive and inductive techniques; generated themes were categorized into the domains of the Technology Acceptance Model (TAM). RESULTS: 3 FG discussions were conducted with a total of 13 clinicians. Overall, clinicians were enthusiastic about the dashboard and expressed the usefulness of visualizing RA outcome trajectories in a graphical format for motivating patients, enhancing patient understanding of their RA outcomes, and improving communication about medications. Major themes that emerged from the FG analysis as barriers to using the dashboard included inconsistent collection of RA outcomes leading to sparse data in the dashboard and concerns about explaining RA outcomes, especially to patients with fibromyalgia. Other challenges included time constraints and technical difficulties refreshing the dashboard to display real-time data. Methods for integrating the dashboard into the visit varied: some clinicians used the dashboard at the beginning of the visit as they documented RA outcomes; others used it at the end to justify changes to therapy; and a few shared it only with stable patients. CONCLUSIONS: The study provides valuable insights into clinicians' perceptions and experiences with the RA PRO dashboard. The dashboard showed promise in enhancing patient-clinician communication, shared decision-making, and overall acceptance among clinicians. Addressing challenges related to data collection, education, and tailoring dashboard use to specific patient populations will be crucial for maximizing its potential impact on RA care. Further research and ongoing improvements in dashboard design and implementation are warranted to ensure its successful integration into routine clinical practice.

Proteomics of novel induced pluripotent stem cell-derived vascular endothelial cells reveal extensive similarity with an immortalized human endothelial cell line.

The vascular endothelium constitutes the inner lining of the blood vessel, and malfunction and injuries of the endothelium can cause cardiovascular diseases as well as other diseases including stroke, tumor growth, and chronic kidney failure. Generation of effective sources to replace injured endothelial cells (ECs) could have significant clinical impact, and somatic cell sources like peripheral or cord blood cannot credibly supply enough endothelial cell progenitors for multitude of treatments. Pluripotent stem cells are a promising source for a reliable EC supply, which have the potential to restore tissue function and treat vascular diseases. We have developed methods to differentiate induced pluripotent stem cells (iPSCs) efficiently and robustly across multiple iPSC lines into nontissue-specific pan vascular ECs (iECs) with high purity. These iECs present with canonical endothelial cell markers and exhibit measures of endothelial cell functionality with the uptake of Dil fluorescent dye-labeled acetylated low-density lipoprotein (Dil-Ac-LDL) and tube formation. Using proteomic analysis, we revealed that the iECs are more proteomically similar to established human umbilical vein ECs (HUVECs) than to iPSCs. Posttranslational modifications (PTMs) were most shared between HUVECs and iECs, and potential targets for increasing the proteomic similarity of iECs to HUVECs were identified. Here we demonstrate an efficient robust method to differentiate iPSCs into functional ECs, and for the first time provide a comprehensive protein expression profile of iECs, which indicates their similarities with a widely used immortalized HUVECs, allowing for further mechanistic studies of EC development, signaling, and metabolism for future regenerative applications.NEW & NOTEWORTHY We have developed methods to differentiate induced pluripotent stem cells (iPSCs) across multiple iPSC lines into nontissue-specific pan vascular ECs (iECs) and demonstrated the proteomic similarity of these cells to a widely used endothelial cell line (HUVECs). We also identified posttranslational modifications and targets for increasing the proteomic similarity of iECs to HUVECs. In the future, iECs can be used to study EC development, signaling, and metabolism for future regenerative applications.

0.18 MG FLUOCINOLONE ACETONIDE INSERT FOR THE TREATMENT OF CHRONIC POSTOPERATIVE PSEUDOPHAKIC CYSTOID MACULAR EDEMA.

PURPOSE: To report the outcomes of the 0.18 mg fluocinolone acetonide insert (FAi) in the treatment of chronic (>6 months) postoperative cystoid macular edema after cataract surgery. METHODS: This was a retrospective consecutive case series of eyes with chronic postoperative cystoid macular edema treated with the FAi. Visual acuity, intraocular pressure, optical coherence tomography metrics, and supplemental therapies were extracted from the charts before and at 3, 6, 12, 18, and 21 months after FAi placement, when available. RESULTS: Nineteen eyes of 13 patients with chronic postoperative cystoid macular edema after cataract surgery underwent FAi placement with an average follow-up of 15.4 months. Ten eyes (52.6%) had a ≥2-line gain in visual acuity. Sixteen eyes (84.2%) had a ≥20% reduction in optical coherence tomography central subfield thickness. Eight eyes (42.1%) had complete resolution of CME. Improvements in central subfield thickness and visual acuity were sustained throughout individual follow-up. Compared with 18 eyes (94.7%) requiring local corticosteroid supplementation before FAi, only six eyes (31.6%) required supplementation after FAi. Similarly, of the 12 eyes (63.2%) that were on corticosteroid drops before FAi, only 3 (15.8%) required drops after FAi. CONCLUSION: Eyes with chronic postoperative cystoid macular edema after cataract surgery treated with the FAi had improved and sustained visual acuity and optical coherence tomography metrics, along with a reduction in supplemental treatment burden.

Peripheral Neurectomy With Customized Nerve Reconstruction for Periorbital Neuropathic Pain: Initial Experience and Clinical Outcomes.

PURPOSE: To describe a novel, minimally invasive surgical technique to treat severe, intractable periorbital neuropathic pain. METHODS: A retrospective analysis of patients with severe, treatment-refractory periorbital pain who underwent transection of affected sensory trigeminal branches with nerve repair was performed. Collected data included etiology and duration of neuropathic pain, comorbidities, prior treatment history, surgical technique including site of transected sensory nerves and type of nerve repair, preoperative and postoperative pain scores as well as follow-up duration. Differences between preoperative and postoperative values were analyzed by the Wilcoxon signed-rank test. RESULTS: A total of 5 patients with severe periorbital neuropathic pain underwent transection of affected supraorbital, supratrochlear, infratrochlear, infraorbital, zygomaticotemporal, and zygomaticofacial nerves with customized nerve reconstruction. All 5 had improvement of periorbital pain after surgery, with 3 (60%) noting complete resolution of pain and 2 (40%) experiencing partial pain relief over a median follow-up period of 9 months (interquartile range [IQR], 6-19 months). Of the 3 patients who had complete resolution of pain, all reported continued pain relief. Median McGill pain scores significantly decreased from 8.4 (IQR, 8.2-10.0) preoperatively to 0.0 (IQR, 0.0-4.8; p < 0.001) postoperatively. All patients reported satisfaction with the surgical procedure and stated that they would undergo the procedure again if given the option. One patient with history of postherpetic neuralgia (PHN) had reactivation of herpes zoster at postoperative month 3, which was self-limited, without worsening of her neuropathic pain. Another patient with PHN required a staged procedure to achieve complete pain relief. CONCLUSION: Peripheral neurectomy with customized reconstruction of involved sensory nerves can successfully reduce and even eradicate periorbital neuropathic pain that was previously recalcitrant to combination pharmacotherapy and prior neurolysis procedures.

Preoperative Serum Albumin Predicts Wound Dehiscence but Not Infection After Surgery for Oral Squamous Cell Carcinoma.

PURPOSE: Inadequate nutrition is common in individuals diagnosed with cancer. The present study evaluated the association between preoperative albumin and postoperative complications in otherwise healthy patients presenting with newly diagnosed squamous cell carcinoma of the oral cavity primarily managed with ablative surgery. PATIENTS AND METHODS: A retrospective cohort study of patients with newly diagnosed oral squamous cell carcinoma from 2005 to 2019 was performed. Patients referred to and managed by a single surgeon (ERC) and who had not received any nutritional support in the preoperative period were included in the study. The primary predictor variable was preoperative albumin level. Other studied variables were patient demographic data and TNM stage. Complications related to primary ablative surgery represented the primary outcome variable. χ2 analysis was completed to assess for significant associations between independent albumin groups (4+, 3.5 to 3.9, and 3.0 to 3.4 g/dL) in relation to postoperative complications. Multivariate logistic regression analysis was completed to control for clinical variables and medical comorbidities when testing the association between albumin and dehiscence. RESULTS: The patient cohort included 268 individuals; of whom, 154 were men. The average age of the patients at surgery was 63 years. When controlling for all other variables, albumin was the only statistically significant predictor of postoperative dehiscence, P = .005. Patients with albumin of 3.5 to 3.9 g/dL had 3.24 times higher odds of dehiscence (95% confidence interval 1.42 to 7.38) in comparison with participants in the 4+ g/dL group. There was no difference of odds between the 3.0 to 3.4 group and the 4+ reference group. CONCLUSIONS: Our study demonstrated that among those individuals meeting the inclusion criteria, there is a statistically significant association between lower albumin levels and postoperative complication rates, specifically dehiscence.

ExpansionHunter: a sequence-graph-based tool to analyze variation in short tandem repeat regions.

SUMMARY: We describe a novel computational method for genotyping repeats using sequence graphs. This method addresses the long-standing need to accurately genotype medically important loci containing repeats adjacent to other variants or imperfect DNA repeats such as polyalanine repeats. Here we introduce a new version of our repeat genotyping software, ExpansionHunter, that uses this method to perform targeted genotyping of a broad class of such loci. AVAILABILITY AND IMPLEMENTATION: ExpansionHunter is implemented in C++ and is available under the Apache License Version 2.0. The source code, documentation, and Linux/macOS binaries are available at https://github.com/Illumina/ExpansionHunter/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

A Multidisciplinary Approach to Synovial Chondromatosis of the Temporomandibular Joint With Cranial Base Involvement: A Brief Review of the Literature and Case Report.

Synovial chondromatosis (SC) is an infrequent, benign condition of unknown etiology affecting the synovium within articular joints. Often considered a metaplastic process, multiple cartilaginous nodules develop in the confines of the synovial membrane. In time, these cartilage nodules develop into fragments, sometimes detaching from the synovium and, thus, become loose in an adjacent synovial cavity. The temporomandibular joint (TMJ) is an unusual site of involvement, with the extracapsular compromise of the cranial base exceedingly rare. A 68-year-old woman presented with a tender mass to the left TMJ that later proved to be SC. Computed tomography illustrated a rare extension of the lesion into the middle cranial fossa. The multidisciplinary effort to remove the mass in its entirety included both oral and maxillofacial surgical and neurosurgical teams. We have reviewed the presentation, diagnosis, surgical treatment, and outcomes of the present case, with diagnostic images and photomicrographs of the lesion included. We also briefly reviewed the reported studies.

Additive Manufacturing of Nanostructures That Are Delicate, Complex, and Smaller than Ever.

Additive manufacturing with two-photon polymerization (TPP) has opened new opportunities for the rapid fabrication of 3D structures with sub-micrometer resolution, but there are still many fabrication constraints associated with this technique. This study details a postprocessing method utilizing oxygen-plasma etching to increase the capabilities of TPP. Underutilized precision in the typical fabrication process allows this subtractive technique to dramatically reduce the minimum achievable feature size. Moreover, since the postprocessing occurs in a dry environment, high aspect ratio features that cannot survive the typical fabrication route can also be achieved. Finally, it is shown that the technique also provides a pathway to realize structures that otherwise are too delicate to be fabricated with TPP, as it enables to introduce temporary support material that can be removed with the plasma. As such, the proposed approach grants access to a massively expanded design domain, providing new capabilities that are long sought in many fields, including optics, biology, robotics, and solid mechanics.

Copy-number variants in clinical genome sequencing: deployment and interpretation for rare and undiagnosed disease.

PURPOSE: Current diagnostic testing for genetic disorders involves serial use of specialized assays spanning multiple technologies. In principle, genome sequencing (GS) can detect all genomic pathogenic variant types on a single platform. Here we evaluate copy-number variant (CNV) calling as part of a clinically accredited GS test. METHODS: We performed analytical validation of CNV calling on 17 reference samples, compared the sensitivity of GS-based variants with those from a clinical microarray, and set a bound on precision using orthogonal technologies. We developed a protocol for family-based analysis of GS-based CNV calls, and deployed this across a clinical cohort of 79 rare and undiagnosed cases. RESULTS: We found that CNV calls from GS are at least as sensitive as those from microarrays, while only creating a modest increase in the number of variants interpreted (~10 CNVs per case). We identified clinically significant CNVs in 15% of the first 79 cases analyzed, all of which were confirmed by an orthogonal approach. The pipeline also enabled discovery of a uniparental disomy (UPD) and a 50% mosaic trisomy 14. Directed analysis of select CNVs enabled breakpoint level resolution of genomic rearrangements and phasing of de novo CNVs. CONCLUSION: Robust identification of CNVs by GS is possible within a clinical testing environment.

Dental care utilization: examining the associations between health services deficits and not having a dental visit in past 12 months.

BACKGROUND: A growing literature supports the contention that closing the divide between dental and medical care can improve access to and coordination of patient care. Health service deficits (HSDs) entail: no routine medical exam, no personal healthcare provider (HCP), no health insurance, and/or delaying medical care because of cost all within the last 12 months. Examining the associations between HSDs and dental care utilization could inform strategies and interventions aimed at narrowing the gap between the medical and dental professions. This study explored whether HSDs are associated with not having a dental care visit within the last 12 months. In addition, the study sought to provide an updated analysis of the characteristics and factors associated with dental care utilization. METHODS: Two thousand sixteen Behavioral Risk Factor Surveillance System survey data were analyzed using bivariate and multivariable techniques. The outcome variable for this study was: last dental visit was longer than 12 months ago. RESULTS: US adults without healthcare insurance, without a personal HCP, who had delayed medical care because of cost, and who had their last routine medical visit longer than 12 months ago had greater odds of not having a dental visit within the last 12 months. Further, this study identified disparities in dental care utilization among males, rural residents, those earning less than $50,000 per year, Non-Hispanic Blacks and Non-Hispanic other races. Individuals with six or more and/or all of their permanent teeth removed and current smokers also had greater odds of not having had a dental care visit in the past 12 months. CONCLUSIONS: Findings suggest that a stronger integration of medical and dental care might increase dental care utilization. In addition, persistent disparities in dental care utilization remain for several demographic groups. Targeted interventions offer the promise of helping achieve HP 2020 goals for improved oral health.

Comparison of multiparametric MRI-based and transrectal ultrasound-based preplans with intraoperative ultrasound-based planning for low dose rate interstitial prostate seed implantation.

PURPOSE: Transrectal ultrasound images are routinely acquired for low dose rate (LDR) prostate brachytherapy dosimetric preplanning (pTRUS), although diagnostic multiparametric magnetic resonance imaging (mpMRI) may serve this purpose as well. We compared the predictive abilities of TRUS vs MRI relative to intraoperative TRUS (iTRUS) to assess the role of mpMRI in brachytherapy preplanning. MATERIALS AND METHODS: Retrospective analysis was performed on 32 patients who underwent iTRUS-guided prostate LDR brachytherapy as either mono- or combination therapy. 56.3% had pTRUS-only volume studies and 43.7% had both 3T-mpMRI and pTRUS preplanning. MRI was used for preplanning and its image fusion with iTRUS was also used for intraoperative guidance of seed placement. Differences in gland volume, seed number, and activity and procedure time were examined, as well as the identification of lesions suspicious for tumor foci. Pearson correlation coefficient and Fisher's Z test were used to estimate associations between continuous measures. RESULTS: There was good correlation of planning volumes between iTRUS and either pTRUS or MRI (r = 0.89, r = 0.77), not impacted by the addition of hormonal therapy (P = 0.65, P = 0.33). Both consistently predicted intraoperative seed number (r = 0.87, r = 0.86). MRI/TRUS fusion did not significantly increase surgical or anesthesia time (P = 0.10, P = 0.46). mpMRI revealed suspicious focal lesions in 11 of 14 cases not visible on pTRUS, that when correlated with histopathology, were incorporated into the plan. CONCLUSIONS: Relative to pTRUS, MRI yielded reliable preplanning measures, supporting the role of MRI-only LDR treatment planning. mpMRI carries numerous diagnostic, staging and preplanning advantages that facilitate better patient selection and delivery of novel dose escalation and targeted therapy, with no additional surgical or anesthesia time. Prospective studies assessing its impact on treatment planning and delivery can serve to establish mpMRI as the standard of care in LDR prostate brachytherapy planning.

LVC Timing in Infant Pig Swallowing and the Effect of Safe Swallowing.

Recurrent laryngeal nerve (RLN) injury in neonates, a complication of head and neck surgeries, leads to increased aspiration risk and swallowing dysfunction. The severity of resulting sequelae range from morbidity, such as aspiration pneumonia, to mortality from infection and failure to thrive. The timing of airway protective events including laryngeal vestibule closure (LVC) is implicated in aspiration. We unilaterally transected the RLN in an infant pig model to observe changes in the timing of swallowing kinematics with lesion and aspiration. We recorded swallows using high-speed video-fluoroscopic swallow studies (VFSS) and scored them using the Infant Mammalian Penetration and Aspiration Scale (IMPAS). We hypothesized that changes would occur in swallowing kinematics (1) between RLN lesion and control animals, and (2) among safe swallows (IMPAS 1), penetration swallows (IMPAS 3), and aspiration swallows (IMPAS 7). We observed numerous changes in timing following RLN lesion in safe and unsafe swallows, suggesting pervasive changes in the coordination of oropharyngeal function. The timing of LVC, posterior tongue, and hyoid movements differed between pre- and post-lesion in safe swallows. Posterior tongue kinematics differed for post-lesion swallows with penetration. The timing and duration of LVC and posterior tongue movement differed between aspiration swallows pre- and post-lesion. After lesion, safe swallows and swallows with aspiration differed in timing of LVC, laryngeal vestibule opening, and posterior tongue and hyoid movements. The timing of thyrohyoid muscle activity varied with IMPAS, but not lesion. Further study into the pathophysiology of RLN lesion-induced swallowing dysfunction is important to developing novel therapies.

Maturation of the Coordination Between Respiration and Deglutition with and Without Recurrent Laryngeal Nerve Lesion in an Animal Model.

The timing of the occurrence of a swallow in a respiratory cycle is critical for safe swallowing, and changes with infant development. Infants with damage to the recurrent laryngeal nerve, which receives sensory information from the larynx and supplies the intrinsic muscles of the larynx, experience a significant incidence of dysphagia. Using our validated infant pig model, we determined the interaction between this nerve damage and the coordination between respiration and swallowing during postnatal development. We recorded 23 infant pigs at two ages (neonatal and older, pre-weaning) feeding on milk with barium using simultaneous high-speed videofluoroscopy and measurements of thoracic movement. With a complete linear model, we tested for changes with maturation, and whether these changes are the same in control and lesioned individuals. We found (1) the timing of swallowing and respiration coordination changes with maturation; (2) no overall effect of RLN lesion on the timing of coordination, but (3) a greater magnitude of maturational change occurs with RLN injury. We also determined that animals with no surgical intervention did not differ from animals that had surgery for marker placement and a sham procedure for nerve lesion. The coordination between respiration and swallowing changes in normal, intact individuals to provide increased airway protection prior to weaning. Further, in animals with an RLN lesion, the maturation process has a larger effect. Finally, these results suggest a high level of brainstem sensorimotor interactions with respect to these two functions.

Redox-Active Glyconanoparticles as Electron Shuttles for Mediated Electron Transfer with Bilirubin Oxidase in Solution.

We demonstrate self-assembly, characterization and bioelectrocatalysis of redox-active cyclodextrin-coated nanoparticles. The nanoparticles with host-guest functionality are easy to assemble and permit entrapment of hydrophobic redox molecules in aqueous solution. Bis-pyrene-ABTS encapsulated nanoparticles were investigated electrochemically and spectroscopically. Their use as electron shuttles is demonstrated via an intraelectron transfer chain between neighboring redox units of clustered particles (Dh,DLS = 195 nm) and the mono- and trinuclear Cu sites of bilirubin oxidases. Enhanced current densities for mediated O2 reduction are observed with the redox nanoparticle system compared to equivalent bioelectrode cells with dissolved mediator. Improved catalytic stability over 2 days was also observed with the redox nanoparticles, highlighting a stabilizing effect of the polymeric architecture. Bioinspired nanoparticles as mediators for bioelectrocatalysis promises to be valuable for future biofuel cells and biosensors.