High Above Knee Amputations for Femoral Osteosarcomas Treated with Free Microsurgical Tibial Reconstruction in the Pediatric Population.

SUMMARY: Improvements in the management of pediatric sarcoma including imaging, neo- and adjuvant therapy, and surgical technique has enhanced long-term survival of patients. Pediatric patients diagnosed with a femoral osteosarcoma undergoing oncologic resection who are ineligible for limb preservation reconstruction or rotationplasty are offered an above knee amputation (AKA). Limb amputations in the skeletally immature patient poses particular problems specific to endosteal bone overgrowth and spiking. Approximately half of these patients undergo revision of their amputation site. Furthermore, a high AKA often requires a hip-based prosthesis, which can be uncomfortable leading to poorer outcomes and higher energy expenditures.We have completed four 'spare parts' microvascular free tibial transfers for pediatric patients diagnosed with femoral osteosarcoma who were treated with an AKA. Two of these patients are currently ambulatory with their prosthetic and have not required long-term revision of their amputation site. One patient demonstrated radiographic evidence of bony union four months post-operatively, but subsequently succumbed to chemotherapy-resistant metastases. The fourth patient is in the process of prosthetic fitting and rehabilitation.This is a novel technique and the first series describing both proximal and distal free microvascular tibial bone transfers as a reconstructive option for pediatric patients with femoral osteosarcomas. It is a reliable flap with possible variations in vascular anatomy. Furthermore, it offers multiple benefits including the prevention of bony spiking, AKA stump augmentation, and facilitation of appropriate prosthetic fitting improving functional outcomes and decreased energy expenditure. However, the soft tissue coverage must be well planned.

The P2X7 Hypothesis of Central Post-Stroke Pain.

The present study examined how P2X7 receptor knockout (KO) modulates central post-stroke pain (CPSP) induced by lesions of the ventrobasal complex (VBC) of the thalamus in behaviors, molecular levels, and electrical recording tests. Following the experimental procedure, the wild-type and P2X7 receptor KO mice were injected with 10 mU/0.2 µL type IV collagenase in the VBC of the thalamus to induce an animal model of stroke-like thalamic hemorrhage. Behavioral data showed that the CPSP group induced thermal and mechanical pain. The P2X7 receptor KO group showed reduced thermal and mechanical pain responses compared to the CPSP group. Molecular assessments revealed that the CPSP group had lower expression of NeuN and KCC2 and higher expression of GFAP, IBA1, and BDNF. The P2X7 KO group showed lower expression of GFAP, IBA1, and BDNF but nonsignificant differences in KCC2 expression than the CPSP group. The expression of NKCC1, GABAa receptor, and TrkB did not differ significantly between the control, CPSP, and P2X7 receptor KO groups. Muscimol, a GABAa agonist, application increased multiunit numbers for monitoring many neurons and [Cl-] outflux in the cytosol in the CPSP group, while P2X7 receptor KO reduced multiunit activity and increased [Cl-] influx compared to the CPSP group. P2X4 receptor expression was significantly decreased in the 100 kDa but not the 50 kDa site in the P2X7 receptor KO group. Altogether, the P2X7 hypothesis of CPSP was proposed, wherein P2X7 receptor KO altered the CPSP pain responses, numbers of astrocytes and microglia, CSD amplitude of the anterior cingulate cortex and the medial dorsal thalamus, BDNF expression, [Cl-] influx, and P2X4 expression in 100 kDa with P2X7 receptors. The present findings have implications for the clinical treatment of CPSP symptoms.

Safety of An Enhanced Recovery After Surgery Protocol After Head and Neck Free Tissue Transfer.

OBJECTIVES: Implementing enhanced recovery after surgery (ERAS) protocols and decreasing length of stay (LOS) have become a priority for major surgeries, including microvascular free tissue transfer (MVFTT) reconstruction of the head and neck. We describe an ERAS protocol with the goal to further reduce length of stay beyond national medians. METHODS: Retrospective chart review between August 2016 and February 2023, including all patients who underwent MVFTT after oral cavity, skull base, salivary gland, and cutaneous ablative surgery. An ERAS protocol was implemented in March 2020. RESULTS: A total of 383 patients were included. Approximately 59.8% underwent oral cavity MVFTT, 34.5% cutaneous and lateral skull base, and 5.8% maxillary and anterior skull base. A total of 209 (54.7%) patients had surgery prior to implementation of the ERAS protocol and 174 (45.3%) after. Median LOS decreased from 9 days (interquartile interval [IQR] 8-11) to 6 (IQR 5-7.5, p < 0.0001) following oral cavity MVFTT. For cutaneous and lateral skull base reconstruction, median LOS decreased from 6 days (IQR 5-8) to 3 (IQR 3-7, p < 0.0001). For anterior skull base and sinonasal MVFTT, median LOS decreased from 8 (IQR 7-9) to 5 days (IQR 4.5-7, p = 0.0005). Rate of discharge to skilled nursing or subacute rehabilitation facilities decreased (24% before ERAS, 9.2% after, p < 0.0001). Thirty-day readmission rate was similar before and after implementation (10.5% vs. 10.3, p = 0.954). Discharge to facility was associated with readmission (OR 2.34, 95% CI 1.12-4.89, p = 0.024). CONCLUSION AND RELEVANCE: Implementation of the ERAS protocol was associated with decreased LOS. There was no increase in rate of readmission. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

Variable PFAS removal by adsorbent media with sufficient prediction of breakthrough despite reduced contact time at pilot scale.

One alternative adsorbent (AA) and five ion exchange (IX) resins were tested for the removal of per- and polyfluoroalkyl substances (PFAS) from groundwater in pilot-scale columns for up to 19 months using empty bed contact times (EBCTs) representative of full-scale treatment. For the six detected PFAS in the pilot feed water, the long-chain PFAS (perfluorooctanoic acid [PFOA], perfluorooctanesulfonic acid [PFOS], and perfluorohexanesulfonic acid [PFHxS]) were well removed with only PFOA, which is a perfluoroalkyl carboxylic acid (PFCA) eventually breaking through as the media became exhausted. Perfluorobutanesulfonic acid (PFBS), a short-chain perfluorosulfonic acid (PFSA), was also well removed, whereas short-chain PFCAs (perfluoropentanoic acid [PFPeA] and perfluorobutanoic acid [PFBA]) were not removed (i.e., immediate breakthrough). Overall, IX and AA demonstrated superior removal of PFSAs compared to PFCAs (i.e., later breakthrough of PFSAs translating to longer media life). Media life varied, ranging from 6 to 15 months before adsorbents reached a significant PFOA breakthrough. The performance of the two adsorbents piloted at shorter EBCT reasonably predicted the longer (representative) pilot EBCT results (within ±20-30%) for the same adsorbents following data scaling. This suggests that pilot-scale testing may be conducted at a faster pace and therefore more economically. PRACTITIONER POINTS: Long-chain PFAS (PFOA, PFOS, and PFHxS) were well removed by five ion exchange and one alternative adsorbent tested herein. One short-chain PFAS (PFBS) was well removed with no removal of two other short-chain PFAS (PFBA and PFPeA). Performance of the two adsorbents piloted at shorter EBCT reasonably predicted the longer (representative) pilot EBCT results for the same adsorbents following data scaling.

SDPR expression in human trabecular meshwork and its potential role in racial disparities of glaucoma.

In order to identify how differential gene expression in the trabecular meshwork (TM) contributes to racial disparities of caveolar protein expression, TM dysfunction and development of primary open angle glaucoma (POAG), RNA sequencing was performed to compare TM tissue obtained from White and Black POAG surgical (trabeculectomy) specimens. Healthy donor TM tissue from White and Black donors was analyzed by PCR, qPCR, immunohistochemistry staining, and Western blot to evaluate SDPR (serum deprivation protein response; Cavin 2) and CAV1/CAV2 (Caveolin 1/Caveolin 2). Standard transmission electron microscopy (TEM) and immunogold labeled studies were performed. RNA sequencing demonstrated reduced SDPR expression in TM from Black vs White POAG patients' surgical specimens, with no significant expression differences in other caveolae-associated genes, confirmed by qPCR analysis. No racial differences in SDPR gene expression were noted in healthy donor tissue by PCR analysis, but there was greater expression as compared to specimens from patients with glaucoma. Analysis of SDPR protein expression confirmed specific expression in the TM regions, but not in adjacent tissues. TEM studies of TM specimens from healthy donors did not demonstrate any racial differences in caveolar morphology, but a significant reduction of caveolae with normal morphology and immuno-gold staining of SDPR were noted in glaucomatous TM as compared to TM from healthy donors. Linkage of SDPR expression levels in TM, POAG development, and caveolar ultrastructural morphology may provide the basis for a novel pathway of exploration of the pathologic mechanisms of glaucoma. Differential gene expression of SDPR in TM from Black vs White subjects with glaucoma may further our understanding of the important public health implications of the racial disparities of this blinding disease.

Parvalbumin interneuron deficiency in the prefrontal and motor cortices of spontaneously hypertensive rats: an attention-deficit hyperactivity disorder animal model insight.

Background: Attention deficit hyperactivity disorder (ADHD) is characterized by impairments in developmental-behavioral inhibition, resulting in impulsivity and hyperactivity. Recent research has underscored cortical inhibition deficiencies in ADHD via the gamma-aminobutyric acid (GABA)ergic system, which is crucial for maintaining excitatory-inhibitory balance in the brain. This study explored postnatal changes in parvalbumin (PV) immunoreactivity, indicating GABAergic interneuron types, in the prefrontal (PFC) and motor (MC) cortices of spontaneously hypertensive rats (SHRs), an ADHD animal model. Methods: Examining PV- positive (PV+) cells associated with dopamine D2 receptors (D2) and the impact of dopamine on GABA synthesis, we also investigated changes in the immunoreactivity of D2 and tyrosine hydroxylase (TH). Brain sections from 4- to 10-week-old SHRs and Wistar Kyoto rats (WKYs) were immunohistochemically analyzed, comparing PV+, D2+ cells, and TH+ fiber densities across age-matched SHRs and WKYs in specific PFC/MC regions. Results: The results revealed significantly reduced PV+ cell density in SHRs: prelimbic (~20% less), anterior cingulate (~15% less), primary (~15% less), and secondary motor (~17% less) cortices. PV+ deficits coincided with the upregulation of D2 in prepubertal SHRs and the downregulation of TH predominantly in pubertal/postpubertal SHRs. Conclusion: Reduced PV+ cells in various PFC regions could contribute to inattention/behavioral alterations in ADHD, while MC deficits could manifest as motor hyperactivity. D2 upregulation and TH deficits may impact GABA synthesis, exacerbating behavioral deficits in ADHD. These findings not only shed new light on ADHD pathophysiology but also pave the way for future research endeavors.

Early and Late Complications of Mandibulectomy Free Flap Reconstruction: Does the Selective Use of Soft Tissue Only Flaps Reduce Complications?

PURPOSE: This study aims to evaluate the factors most associated with early and late complications following microvascular free tissue transfer (MVFTT) after mandibulectomy. METHODS: A retrospective review of patients undergoing MVFTT after segmental mandibulectomy from September 2016 to February 2021 was performed across a single academic institution. Surgical variables were collected, including the location of the resultant mandibular defect (anterior vs posterior) and flap type (osseous or non-osseous). The primary outcome variables included postoperative complications (early, <90 days; and late, >90 days) and the patients' functional status (return to oral intake). Descriptive statistics, chi-square test, Fischer's exact test, and 2-sample t tests were used to analyze differences among variables. RESULTS: We analyzed a cohort of 114 consecutive patients with mandibular defects, comprising 57 anterior and 57 posterior defects. Bony free flaps with hardware were used to reconstruct 98% of anterior defects compared to 58% of posterior defects (P < .001). All soft tissue only flaps did not utilize any hardware during the reconstruction. Anterior defects demonstrated more late complications requiring additional surgery (30% vs 9%, P = .04). A secondary analysis of posterior mandibular reconstructions compared soft tissue only flaps and bony free flaps with hardware and showed equivalent rates of early (12% vs 13%, P > .99) and late (9% vs 8%, P > .99) complications requiring additional surgery while demonstrating a similar return to full oral competence (55% vs 46%, P = .52) and recovery of a 100% oral diet (67% vs 54%, P = .53). CONCLUSION: Osseous free tissue transfer for segmental mandibular defects remains the gold standard in reconstruction. In our patient cohort, anterior mandibular defects are associated with greater late (>90 day) complications requiring additional surgery. Comparable outcomes may be achieved with soft tissue only versus osseous free flap reconstruction of posterior mandibular defects.

Reconstruction for Salvage Laryngectomy With Limited Pharyngectomy.

Importance: Closure technique for optimization of postoperative and functional outcomes following salvage laryngectomy remains an area of debate among head and neck surgeons. Objective: To investigate the association of salvage laryngectomy closure technique with early postoperative and functional outcomes. Design, Setting, and Participants: This retrospective cohort study included patients from 17 academic, tertiary care centers who underwent total laryngectomy with no or limited pharyngectomy after completing a course of definitive radiotherapy or chemoradiotherapy with curative intent between January 2011 and December 2016. Patients with defects not amenable to primary closure were excluded. Data were analyzed from February 14, 2021, to January 29, 2024. Exposures: Total laryngectomy with and without limited pharyngectomy, reconstructed by primary mucosal closure (PC), regional closure (RC), or free tissue transfer (FTT). Main Outcomes and Measures: Patients were stratified on the basis of the pharyngeal closure technique. Perioperative and long-term functional outcomes were evaluated with bivariate analyses. A multivariable regression model adjusted for historical risk factors for pharyngocutaneous fistula (PCF) was used to assess risk associated with closure technique. Relative risks (RRs) with 95% CIs were determined. Results: The study included 309 patients (256 [82.8%] male; mean age, 64.7 [range, 58.0-72.0] years). Defects were reconstructed as follows: FTT (161 patients [52.1%]), RC (64 [20.7%]), and PC (84 [27.2%]). A PCF was noted in 36 of 161 patients in the FTT group (22.4%), 25 of 64 in the RC group (39.1%), and 29 of 84 in the PC group (34.5%). On multivariable analysis, patients undergoing PC or RC had a higher risk of PCF compared with those undergoing FTT (PC: RR, 2.2 [95% CI, 1.1-4.4]; RC: RR, 2.5 [95% CI, 1.3-4.8]). Undergoing FTT was associated with a clinically meaningful reduction in risk of PCF (RR, 0.6; 95% CI, 0.4-0.9; number needed to treat, 7). Subgroup analysis comparing inset techniques for the RC group showed a higher risk of PCF associated with PC (RR, 1.8; 95% CI, 1.1-3.0) and predominately pectoralis myofascial flap with onlay technique (RR, 1.9; 95% CI, 1.2-3.2), but there was no association of pectoralis myocutaneous flap with cutaneous paddle interposition with PCF (RR, 1.2; 95% CI, 0.5-2.8) compared with FTT with cutaneous inset. There were no clinically significant differences in functional outcomes between the groups. Conclusion and Relevance: In this study of patients with limited pharyngeal defects, interpositional fasciocutaneous closure technique was associated with reduced risk of PCF in the salvage setting, which is most commonly achieved by FTT in academic practices. Closure technique was not associated with functional outcomes at 1 and 2 years postoperatively.

(Don't) look where you are going: Evidence for a travel direction signal in humans that is independent of head direction.

We often assume that travel direction is redundant with head direction, but from first principles, these two factors provide differing spatial information. Although head direction has been found to be a fundamental component of human navigation, it is unclear how self-motion signals for travel direction contribute to forming a travel trajectory. Employing a novel motion adaptation paradigm from visual neuroscience designed to preclude a contribution of head direction, we found high-level aftereffects of perceived travel direction, indicating that travel direction is a fundamental component of human navigation. Interestingly, we discovered a higher frequency of reporting perceived travel toward the adapted direction compared to a no-adapt control-an aftereffect that runs contrary to low-level motion aftereffects. This travel aftereffect was maintained after controlling for possible response biases and approaching effects, and it scaled with adaptation duration. These findings demonstrate the first evidence of how a pure travel direction signal might be represented in humans, independent of head direction. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Does preoperative opioid use predict outcomes to 6 months following primary unilateral knee or hip arthroplasty for osteoarthritis? A data-linked retrospective study.

BACKGROUND: Few Australian studies have examined the incidence of prescribed opioid use prior to primary total knee or total hip arthroplasty (TKA, THA) and whether it predicts post-surgery outcomes. A recent Australian study demonstrated that the prevalence of pre-arthroplasty opioid use was approximately 16%. In the United States, approximately 24% of people undergoing TKA or THA are chronic opioid users preoperatively. PURPOSE: This study aimed to determine (i) the proportion of TKA and THA patients who use prescribed opioids regularly (daily) before surgery (i.e., opioid use reported between the time of waitlisting and any time up to 3 months before surgery), (ii) if opioid use before surgery predicts (a) complication/readmission rates to 6-months post-surgery, and (b) patient-reported outcomes to 6-months post-surgery. METHODS: A retrospective cohort study of patients who underwent TKA or THA between January 2013 and June 2018 from two Australian public hospitals was undertaken utilizing linked individual patient-level data from two prospectively collected independent databases comprising approximately 3,500 and 9,500 people (database contained known opioid usage data within the 5-year time frame). Inclusion criteria included (i) primary diagnosis of osteoarthritis of the index joint, (ii) primary elective THA or TKA, and (iii) age ≥ 18 years. Exclusion criteria included (i) revision arthroplasty, (ii) non-elective arthroplasty, (iii) hip hemiarthroplasty, (iv) uni-compartmental knee arthroplasty, and (v) previous unilateral high tibial osteotomy. RESULTS: Analysis was completed on 1,187 study participants (64% female, 69% TKA, mean (SD) age 67 [9.9]). 30% were using regular opioids preoperatively. Adjusted regression analyses controlling for multiple co-variates indicated no significant association between preoperative opioid use and complications/readmission rates or patient-reported outcomes to 6 months post-surgery. Model diagnostics produced poor discrimination for area under the curves and non-significant goodness of fit tests. Pre-arthroplasty opioid use was associated with lower health-related quality of life (EuroQol-Visual Analogue Scale) compared to non-opioid users undergoing primary THA (mean difference -5.04 [-9.87, -0.22], P = 0.04, Adjusted R2 = 0.06) CONCLUSION: In this study, 30% of patients were using prescribed opioids daily prior to primary TKA or THA. Pre-arthroplasty opioid use was not associated with postoperative adverse events or patient-reported pain, function, or global perceived improvement up to six months post-surgery.

Occupancy trends of overwintering coastal waterbird communities reveal guild-specific patterns of redistribution and shifting reliance on existing protected areas.

Climate change and anthropogenic stressors are redistributing species and altering community composition globally. Protected areas (PAs) may not sufficiently protect populations of species undergoing distributional shifts, necessitating that we evaluate existing PAs and identify areas for future protection to conserve biodiversity across regional and temporal scales. Coastal waterbirds are important indicators of marine ecosystem health, representing mobile, long-lived, higher trophic-level consumers. Using a 20-year citizen science dataset (1999-2019) with a before-after control-intervention sampling framework for habitat protection, we applied dynamic occupancy models to assess winter occupancy trends along the Pacific coast of Canada. Specifically, we sought to understand potential drivers of regional declines, spatial commonalities among guilds, and changes in habitat use before and after PA designation, as well as between PAs and non-PAs. Occupancy trends varied regionally, with greater declines in the south compared to the north. Regional differences underlined potential range shifts, particularly for species with traits linked to temperature tolerance, movement, and high productivity foraging, as cold-tolerant, migratory benthivores and piscivores wintered farther north relative to 20 years ago or retreated to cold-water fjords. While 21 of 57 (36.8%) species responded positively to PA designation (before-after), greater occupancy declines tended to occur in PAs established pre-1999 relative to non-PAs (control-intervention). Since PAs are currently concentrated in the south, negative associations were most apparent for species retreating northward, but existing PAs may have a stabilizing or transitory effect on southern wintering species shifting into the region from farther south. We emphasize that conservation strategies must balance persistence of current communities with preserving the climate-adapted biodiversity of tomorrow by accounting for community-level effects of species moving into and out of existing PAs. Incorporating range shifts into PA planning by predicting distributional changes will allow conservation practitioners to identify priority habitats, such as cold-water refugia, for persistent wildlife communities.

Le changement climatique et les facteurs de stress anthropiques redistribuent les espèces et modifient la composition des communautés à l'échelle mondiale. Les zones protégées (ZP) ne protègent peut-être pas suffisamment les populations d'espèces qui subissent des changements de répartition, ce qui nous oblige à évaluer les ZP existantes et à identifier les zones à protéger à l'avenir pour conserver la biodiversité à l'échelle régionale et temporelle. Les oiseaux côtiers sont des indicateurs importants de la santé des écosystèmes marins, car ils représentent des consommateurs mobiles, ont une longue durée de vie et représente le niveau trophique supérieur. En utilisant un ensemble de données de science participative sur 20 ans (1999-2019) avec un échantillonnage avant-après contrôle-intervention (AACI) pour la protection de l'habitat, nous avons appliqué des modèles d'occupation dynamiques pour évaluer les tendances de l'occupation hivernale le long de la côte pacifique du Canada. Plus précisément, nous avons cherché à comprendre les moteurs potentiels des déclins régionaux, les points communs spatiaux entre les guildes et les changements dans l'utilisation de l'habitat avant et après la désignation de le ZP, ainsi qu'entre les ZP et les non-ZP. Les tendances en matière d'occupation varient d'une région à l'autre, avec des déclins plus importants dans le sud que dans le nord. Les différences régionales soulignent les déplacements potentiels de l'aire de répartition, en particulier pour les espèces dont les caractéristiques sont liées à la tolérance à la température, aux déplacements et à la recherche de nourriture à rendement élevé, car les benthivores et les piscivores migrateurs tolérants au froid ont hiverné plus au nord qu'il y a 20 ans ou se sont retirés dans les fjords aux eaux froides. Alors que 21 des 57 (36,8 %) espèces ont réagi positivement à la désignation des aires protégées (avant-après), les baisses d'occupation ont eu tendance à être plus importantes dans les aires protégées créées avant 1999 que dans les aires non protégées (contrôle-intervention). Comme les aires protégées sont actuellement concentrées dans le sud, les associations négatives étaient plus évidentes pour les espèces qui se retirent vers le nord, mais les aires protégées existantes peuvent avoir un effet stabilisateur ou transitoire sur les espèces hivernant dans le sud qui se déplacent dans la région à partir d'une région plus au sud. Nous soulignons que les stratégies de conservation doivent trouver un équilibre entre la persistance des communautés actuelles et la préservation de la biodiversité adaptée au climat de demain, en tenant compte des effets au niveau des communautés des espèces qui entrent dans les aires protégées existantes ou qui en sortent. L'intégration des changements d'aire de répartition dans la planification des aires protégées en prédisant les changements de distribution permettra aux praticiens de la conservation d'identifier les habitats prioritaires, tels que les refuges d'eau froide, pour les communautés d'espèces sauvages persistantes.

Dysregulation of Neuropilin-2 Expression in Inhibitory Neurons Impairs Hippocampal Circuit Development Leading to Autism-Epilepsy Phenotype.

Dysregulation of development, migration, and function of interneurons, collectively termed interneuronopathies, have been proposed as a shared mechanism for autism spectrum disorders (ASDs) and childhood epilepsy. Neuropilin-2 (Nrp2), a candidate ASD gene, is a critical regulator of interneuron migration from the median ganglionic eminence (MGE) to the pallium, including the hippocampus. While clinical studies have identified Nrp2 polymorphisms in patients with ASD, whether dysregulation of Nrp2-dependent interneuron migration contributes to pathogenesis of ASD and epilepsy has not been tested. We tested the hypothesis that the lack of Nrp2 in MGE-derived interneuron precursors disrupts the excitation/inhibition balance in hippocampal circuits, thus predisposing the network to seizures and behavioral patterns associated with ASD. Embryonic deletion of Nrp2 during the developmental period for migration of MGE derived interneuron precursors (iCKO) significantly reduced parvalbumin, neuropeptide Y, and somatostatin positive neurons in the hippocampal CA1. Consequently, when compared to controls, the frequency of inhibitory synaptic currents in CA1 pyramidal cells was reduced while frequency of excitatory synaptic currents was increased in iCKO mice. Although passive and active membrane properties of CA1 pyramidal cells were unchanged, iCKO mice showed enhanced susceptibility to chemically evoked seizures. Moreover, iCKO mice exhibited selective behavioral deficits in both preference for social novelty and goal-directed learning, which are consistent with ASD-like phenotype. Together, our findings show that disruption of developmental Nrp2 regulation of interneuron circuit establishment, produces ASD-like behaviors and enhanced risk for epilepsy. These results support the developmental interneuronopathy hypothesis of ASD epilepsy comorbidity.

Dysregulation of Neuropilin-2 Expression in Inhibitory Neurons Impairs Hippocampal Circuit Development Leading to Autism-Epilepsy Phenotype.

Dysregulation of development, migration, and function of interneurons, collectively termed interneuronopathies, have been proposed as a shared mechanism for autism spectrum disorders (ASDs) and childhood epilepsy. Neuropilin-2 (Nrp2), a candidate ASD gene, is a critical regulator of interneuron migration from the median ganglionic eminence (MGE) to the pallium, including the hippocampus. While clinical studies have identified Nrp2 polymorphisms in patients with ASD, whether dysregulation of Nrp2-dependent interneuron migration contributes to pathogenesis of ASD and epilepsy has not been tested. We tested the hypothesis that the lack of Nrp2 in MGE-derived interneuron precursors disrupts the excitation/inhibition balance in hippocampal circuits, thus predisposing the network to seizures and behavioral patterns associated with ASD. Embryonic deletion of Nrp2 during the developmental period for migration of MGE derived interneuron precursors (iCKO) significantly reduced parvalbumin, neuropeptide Y, and somatostatin positive neurons in the hippocampal CA1. Consequently, when compared to controls, the frequency of inhibitory synaptic currents in CA1 pyramidal cells was reduced while frequency of excitatory synaptic currents was increased in iCKO mice. Although passive and active membrane properties of CA1 pyramidal cells were unchanged, iCKO mice showed enhanced susceptibility to chemically evoked seizures. Moreover, iCKO mice exhibited selective behavioral deficits in both preference for social novelty and goal-directed learning, which are consistent with ASD-like phenotype. Together, our findings show that disruption of developmental Nrp2 regulation of interneuron circuit establishment, produces ASD-like behaviors and enhanced risk for epilepsy. These results support the developmental interneuronopathy hypothesis of ASD epilepsy comorbidity.

Pronounced differentiation on the Z chromosome and parts of the autosomes in crowned sparrows contrasts with mitochondrial paraphyly: implications for speciation.

When a single species evolves into multiple descendent species, some parts of the genome can play a key role in the evolution of reproductive isolation while other parts flow between the evolving species via interbreeding. Genomic evolution during the speciation process is particularly interesting when major components of the genome-for instance, sex chromosomes vs. autosomes vs. mitochondrial DNA-show widely differing patterns of relationships between three diverging populations. The golden-crowned sparrow (Zonotrichia atricapilla) and the white-crowned sparrow (Zonotrichia leucophrys) are phenotypically differentiated sister species that are largely reproductively isolated despite possessing similar mitochondrial genomes, likely due to recent introgression. We assessed variation in more than 45,000 single nucleotide polymorphisms to determine the structure of nuclear genomic differentiation between these species and between two hybridizing subspecies of Z. leucophrys. The two Z. leucophrys subspecies show moderate levels of relative differentiation and patterns consistent with a history of recurrent selection in both ancestral and daughter populations, with much of the sex chromosome Z and a large region on the autosome 1A showing increased differentiation compared to the rest of the genome. The two species Z. leucophrys and Z. atricapilla show high relative differentiation and strong heterogeneity in the level of differentiation among various chromosomal regions, with a large portion of the sex chromosome (Z) showing highly divergent haplotypes between these species. Studies of speciation often emphasize mitochondrial DNA differentiation, but speciation between Z. atricapilla and Z. leucophrys appears primarily associated with Z chromosome divergence and more moderately associated with autosomal differentiation, whereas mitochondria are highly similar due apparently to recent introgression. These results add to the growing body of evidence for highly heterogeneous patterns of genomic differentiation during speciation, with some genomic regions showing a lack of gene flow between populations many hundreds of thousands of years before other genomic regions.

Perforator-based chimeric ulnar forearm microvascular free tissue transfer reconstruction of post-radiated tracheoesophageal puncture fistulae.

Tracheoesophageal puncture (TEP) performed during total laryngectomy in the primary treatment of laryngeal cancer is the standard method for voice restoration. Following adjuvant radiotherapy, the TEP site can experience complications resulting in a tracheoesophageal fistula (TEF) with chronic leakage making oral alimentation unsafe due to aspiration. Here, we describe a technique using chimeric ulnar artery perforator forearm free flaps (UAPFF) in the reconstruction of these complex deformities. Four patients underwent chimeric UAPFF reconstruction of TEP site TEFs following primary TL with TEP and adjuvant radiotherapy. No flap failures or surgical complications occurred. Average time from end of radiotherapy to persistent TEF was 66 months (range 4-190 months). All patients had resolution in their TEF with average time to total oral diet achievement of 22 days (14-42 days). Chimeric UAPFF reconstruction is a safe and effective method to reconstruct recalcitrant TEP site TEFs.

Outcome Comparison of Functional Laryngectomy for the Dysfunctional Larynx to Salvage Laryngectomy.

OBJECTIVE: To compare functional outcomes of total laryngectomy (TL) with microvascular free tissue transfer (MVFTT) reconstruction in the treatment of dysfunctional larynx (DL) versus salvage therapy for locally recurrent disease in patients with a history of laryngeal squamous cell carcinoma (SCC). METHODS: Retrospective review from a tertiary medical center between August 2015 and August 2022. RESULTS: Sixty-nine patients underwent TL with MVFTT following primary laryngeal radiation or chemoradiation; 15 (22%) patients underwent functional laryngectomy (FL) and 54 (78%) underwent a salvage laryngectomy (SL). There were no total flap failures. Four (6%) patients developed a pharyngocutaneous fistula; one (7%) FL patient and 3 (6%) in the SL cohort. There was no significant difference in average hospital length of stay (LOS) between the cohorts (8.6 ± 3.0 days vs. 12.8 ± 10.1 days, p = 0.12). All patients (100%) in the FL cohort achieved a total oral diet compared to 41 (76%) in the SL cohort (p = 0.03). Two (13%) and 10 (19%) patients developed pharyngoesophageal stenosis in the FL and SL cohorts, respectively (p = 1.0). Nine (60%) and 23 (43%) patients in the FL and SL cohorts underwent tracheoesophageal puncture (TEP) placement, with 89% and 91% achieving fluency, respectively (p = 0.23). CONCLUSION: Although the role of TL for the definitive treatment of laryngeal SCC has decreased over the past 30 years, organ-preservation protocols can impact speech, swallowing, and airway protection with life-threatening consequences. The use of elective FL with MVFTT for the treatment of DL results in similar or better functional outcomes compared to SL for recurrent disease. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:222-227, 2024.

Outcomes of Head and Neck Microvascular Free Tissue Transfer for Advanced Cutaneous Squamous Cell Carcinoma: A Comparison of Solid Organ Transplant Recipients to Nontransplant Patients.

BACKGROUND: Patients with solid organ transplant (SOT) are at increased risk of developing aggressive cutaneous malignancies due to their immunosuppression, particularly cutaneous squamous cell carcinoma (cSCC). PURPOSE: There is limited data regarding SOT patients with locally advanced cSCC requiring radical surgery and microvascular free tissue transfer (MVFTT). Our objectives were to characterize outcomes in SOT patients and compare them with a non-SOT cohort. STUDY DESIGN: This is a retrospective cohort study of patients undergoing MVFTT for advanced cSCC of the head and neck between January 2016 and May 2020 at a tertiary referral center. Patients who underwent MVFTT as part of curative intent surgery for advanced cSCC during the study were considered for inclusion. Exclusion criteria included distant metastasis, palliative intent treatment, age less than 18 years, and lip primaries. PREDICTOR: The predictor variable was SOT status. A cohort of non-SOT patients was matched to the SOT cohort based on age, smoking status, tumor stage, and defect size. MAIN OUTCOME VARIABLES: The primary reconstructive outcome was the major surgical complications and secondary outcome measures included major medical complications and minor surgical complications. The primary oncologic outcome was overall survival and the secondary outcome was disease-specific survival. The primary predictor was transplant status. COVARIATES: Covariates included patient comorbidities, prior treatment, tumor stage, type of reconstruction, pathologic findings, and adjuvant therapy. ANALYSIS: Continuous and categorical variables were compared using Student's T test and Fisher's exact test. Survival was calculated using the Kaplan-Meier method and differences in survival between groups were calculated using the log-rank test. Statistical significance was set a priori at P ≤ .05. RESULTS: Fourteen SOT and 14 matched non-SOT patients met inclusion criteria. There was not a statistically significant difference in the rate of major surgical complications (7 vs 7%, P = .74) between the SOT and non-SOT cohorts. Rates of minor (21 vs 43%, P = .26) wound complications and medical complications (0 vs 14%, P = .24) were also similar between the SOT and non-SOT cohorts. Locoregional recurrences and distant metastasis were more common for SOT patients, though this was not statistically significant. Overall survival was significantly worse for SOT patients (21.7 vs 31.0 months, P = .04), though there was not a significant difference in disease-free survival (9.8 vs 31.0 months, P = .17). CONCLUSIONS AND RELEVANCE: MVFTT in the management of SOT patients with locally advanced head and neck cSCC demonstrates similar complication rates with non-SOT patients. While survival and oncologic outcomes are worse in the SOT cohort, aggressive surgical intervention with MVFTT can be performed with comparable complication rates to patients without a history of SOT.

Rapid identification of enteric bacteria from whole genome sequences using average nucleotide identity metrics.

Identification of enteric bacteria species by whole genome sequence (WGS) analysis requires a rapid and an easily standardized approach. We leveraged the principles of average nucleotide identity using MUMmer (ANIm) software, which calculates the percent bases aligned between two bacterial genomes and their corresponding ANI values, to set threshold values for determining species consistent with the conventional identification methods of known species. The performance of species identification was evaluated using two datasets: the Reference Genome Dataset v2 (RGDv2), consisting of 43 enteric genome assemblies representing 32 species, and the Test Genome Dataset (TGDv1), comprising 454 genome assemblies which is designed to represent all species needed to query for identification, as well as rare and closely related species. The RGDv2 contains six Campylobacter spp., three Escherichia/Shigella spp., one Grimontia hollisae, six Listeria spp., one Photobacterium damselae, two Salmonella spp., and thirteen Vibrio spp., while the TGDv1 contains 454 enteric bacterial genomes representing 42 different species. The analysis showed that, when a standard minimum of 70% genome bases alignment existed, the ANI threshold values determined for these species were ≥95 for Escherichia/Shigella and Vibrio species, ≥93% for Salmonella species, and ≥92% for Campylobacter and Listeria species. Using these metrics, the RGDv2 accurately classified all validation strains in TGDv1 at the species level, which is consistent with the classification based on previous gold standard methods.

Free Flap Outcomes for Head and Neck Surgery in Patients with COVID-19.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) affects the vascular system, subjecting patients to a hypercoagulable state. This is of particular concern for the success of microvascular free flap reconstruction. This study aims to report head and neck free flap complications in patients with COVID-19 during the perioperative period. We believe these patients are more likely to experience flap complications given the hypercoagulable state. METHODS: This is a multi-institutional retrospective case series of patients infected with COVID-19 during the perioperative period for head and neck free flap reconstruction from March 2020 to January 2022. RESULTS: Data was collected on 40 patients from 14 institutions. Twenty-one patients (52.5%) had a positive COVID-19 test within 10 days before surgery and 7 days after surgery. The remaining patients had a positive test earlier than 10 days before surgery. A positive test caused a delay in surgery for 16 patients (40.0%) with an average delay of 44.7 days (9-198 days). Two free flap complications (5.0%) occurred with no free flap deaths. Four patients (10.0%) had surgical complications and 10 patients had medical complications (25.0%). Five patients (12.5%) suffered from postoperative COVID-19 pneumonia. Three deaths were COVID-19-related and one from cancer recurrence during the study period. CONCLUSION: Despite the heightened risk of coagulopathy in COVID-19 patients, head and neck free flap reconstructions in patients with COVID-19 are not at higher risk for free flap complications. However, these patients are at increased risk of medical complications. LEVEL OF EVIDENCE: 4 Laryngoscope, 2023.