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Tumor-infiltrating regulatory T cells (TI-Tregs) elicit immunosuppressive effects in the tumor microenvironment (TME) leading to accelerated tumor growth and resistance to immunotherapies against solid tumors. Here, we demonstrate that poly-(ADP-ribose)-polymerase-11 (PARP11) is an essential regulator of immunosuppressive activities of TI-Tregs. Expression of PARP11 correlates with TI-Treg cell numbers and poor responses to immune checkpoint blockade (ICB) in human patients with cancer. Tumor-derived factors including adenosine and prostaglandin E2 induce PARP11 in TI-Tregs. Knockout of PARP11 in the cells of the TME or treatment of tumor-bearing mice with selective PARP11 inhibitor ITK7 inactivates TI-Tregs and reinvigorates anti-tumor immune responses. Accordingly, ITK7 decelerates tumor growth and significantly increases the efficacy of anti-tumor immunotherapies including ICB and adoptive transfer of chimeric antigen receptor (CAR) T cells. These results characterize PARP11 as a key driver of TI-Treg activities and a major regulator of immunosuppressive TME and argue for targeting PARP11 to augment anti-cancer immunotherapies.
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Inmunoterapia , Poli(ADP-Ribosa) Polimerasas , Linfocitos T Reguladores , Microambiente Tumoral , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/efectos de los fármacos , Animales , Humanos , Ratones , Microambiente Tumoral/inmunología , Microambiente Tumoral/efectos de los fármacos , Inmunoterapia/métodos , Poli(ADP-Ribosa) Polimerasas/metabolismo , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/efectos de los fármacos , Línea Celular Tumoral , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Ratones Endogámicos C57BL , Neoplasias/inmunología , Neoplasias/terapiaRESUMEN
The prevailing view on post-translational modifications (PTMs) is that amino acid side chains in proteins are modified with a single PTM at any given time. However, a growing body of work has demonstrated crosstalk between different PTMs, some occurring on the same residue. Such interplay is seen with ADP-ribosylation and ubiquitylation, where specialized E3 ligases ubiquitylate targets for proteasomal degradation in an ADP-ribosylation-dependent manner. More recently, the DELTEX family of E3 ligases was reported to catalyze ubiquitylation of the 3'- hydroxy group of the adenine-proximal ribose of free NAD + and ADP-ribose in vitro , generating a non-canonical ubiquitin ester-linked species. In this report, we show, for the first time, that this dual PTM occurs in cells on mono-ADP-ribosylated (MARylated) PARP10 on Glu/Asp sites to form a MAR ubiquitin ester (MARUbe). We term this process m ono- A DP-ribosyl ub iquit ylation or MARUbylation. Using chemical and enzymatic treatments, including a newly characterized bacterial deubiquitinase with esterase-specific activity, we discovered that PARP10 MARUbylation is extended with K11-linked polyubiquitin chains. Finally, mechanistic studies using proteasomal and ubiquitin-activating enzyme inhibitors demonstrated that PARP10 MARUbylation leads to its proteasomal degradation, providing a functional role for this new PTM in regulating protein turnover.
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The Islamist group ISIS has been particularly successful at recruiting Westerners as terrorists. A hypothesized explanation is their simultaneous use of two types of propaganda: Heroic narratives, emphasizing individual glory, alongside Social narratives, which emphasize oppression against Islamic communities. In the current study, functional MRI was used to measure brain responses to short ISIS propaganda videos distributed online. Participants were shown 4 Heroic and 4 Social videos categorized as such by another independent group of subjects. Persuasiveness was measured using post-scan predictions of recruitment effectiveness. Inter-subject correlation (ISC) was used to measure commonality of brain activity time courses across individuals. ISCs in ventral striatum predicted rated persuasiveness for Heroic videos, while ISCs in mentalizing and default networks, especially in dmPFC, predicted rated persuasiveness for Social videos. This work builds on past findings that engagement of the reward circuit and of mentalizing brain regions predicts preferences and persuasion. The observed dissociation as a function of stimulus type is novel, as is the finding that intersubject synchrony in ventral striatum predicts rated persuasiveness. These exploratory results identify possible neural mechanisms by which political extremists successfully recruit prospective members and specifically support the hypothesized distinction between Heroic and Social narratives for ISIS propaganda.
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Encéfalo , Imagen por Resonancia Magnética , Recompensa , Humanos , Masculino , Femenino , Adulto , Imagen por Resonancia Magnética/métodos , Adulto Joven , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Comunicación Persuasiva , Islamismo , Mentalización/fisiología , Mapeo Encefálico/métodos , Estriado Ventral/fisiología , Estriado Ventral/diagnóstico por imagen , Grabación en Video , Teoría de la Mente/fisiologíaRESUMEN
ADP-ribosylation, the transfer of ADP-ribose (ADPr) from nico-tinamide adenine dinucleotide (NAD+) groups to proteins, is a conserved post-translational modification (PTM) that occurs most prominently in response to DNA damage. ADP-ribosylation is a dynamic PTM regulated by writers (PARPs), erasers (ADPr hy-drolases), and readers (ADPR binders). PARP1 is the primary DNA damage-response writer responsible for adding a polymer of ADPR to proteins (PARylation). Real-time monitoring of PARP1-mediated PARylation, especially in live cells, is critical for under-standing the spatial and temporal regulation of this unique PTM. Here, we describe a genetically encoded FRET probe (pARS) for semi-quantitative monitoring of PARylation dynamics. pARS feature a PAR-binding WWE domain flanked with turquoise and Venus. With a ratiometric readout and excellent signal-to-noise characteristics, we show that pARS can monitor PARP1-dependent PARylation temporally and spatially in real-time. pARS provided unique insights into PARP1-mediated PARylation kinetics in vitro and high-sensitivity detection of PARylation in live cells, even under mild DNA damage. We also show that pARS can be used to determine the potency of PARP inhibitors in vitro and, for the first time, in live cells in response to DNA damage. The robustness and ease of use of pARS make it an important tool for the PARP field.
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The experience of a reward appears to enhance memory for recent prior events, adaptively making that information more available to guide future decision-making. Here, we tested whether reward enhances memory for associative item-location information and also whether the effect of reward spreads to other categorically-related but unrewarded items. Participants earned either points (Experiment 1) or money (Experiment 2) through a time-estimation reward task, during which stimuli-location pairings around a 2D-ring were shown followed by either high-value or low-value rewards. All stimuli were then tested for location memory or recognition (yes/no), immediately and after a 24-hour delay. Across both experiments (combined analysis), there was a robust improvement in location memory following high-value rewards, even though evidence supporting this effect was reliable in Experiment 2 but not in Experiment 1. The memory-enhancing effect of reward was observed on both the immediate and delayed location-memory tests. Reward-enhanced memory for both directly rewarded stimuli and categorically related stimuli that were not directly rewarded. No reliable effect of reward value on yes/no recognition-memory performance was observed in either experiment. We hypothesise that reward enhances the consolidation of recent experience and conceptually related memories to make these more available for future decisions.
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Myhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016-2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence-based guidelines in anticipation of disease-specific therapies.
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PARP14 is a 203 kDa multi-domain protein that is primarily known as an ADP-ribosyltransferase, and is involved in a variety of cellular functions including DNA damage, microglial activation, inflammation, and cancer progression. In addition, PARP14 is upregulated by interferon (IFN), indicating a role in the antiviral response. Furthermore, PARP14 has evolved under positive selection, again indicating that it is involved in host-pathogen conflict. We found that PARP14 is required for increased IFN-I production in response to coronavirus infection lacking ADP-ribosylhydrolase (ARH) activity and poly(I:C), however, whether it has direct antiviral function remains unclear. Here we demonstrate that the catalytic activity of PARP14 enhances IFN-I and IFN-III responses and restricts ARH-deficient murine hepatitis virus (MHV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. To determine if PARP14's antiviral functions extended beyond CoVs, we tested the ability of herpes simplex virus 1 (HSV-1) and several negative-sense RNA viruses, including vesicular stomatitis virus (VSV), Ebola virus (EBOV), and Nipah virus (NiV), to infect A549 PARP14 knockout (KO) cells. HSV-1 had increased replication in PARP14 KO cells, indicating that PARP14 restricts HSV-1 replication. In contrast, PARP14 was critical for the efficient infection of VSV, EBOV, and NiV, with EBOV infectivity at less than 1% of WT cells. A PARP14 active site inhibitor had no impact on HSV-1 or EBOV infection, indicating that its effect on these viruses was independent of its catalytic activity. These data demonstrate that PARP14 promotes IFN production and has both pro- and anti-viral functions targeting multiple viruses.
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Robotic-assisted surgery has gained popularity for otolaryngology procedures. It provides high-definition images and surgical precision to perform diverse procedures. It is an alternative to the operating microscope, endoscope, or exoscope when reaching hidden anatomical structures in the ear. In this proof-of-concept study, we aim to demonstrate the possibility of using a robotic-assisted device to perform ear surgery in conjunction with the microscope or the endoscope. In total, there were 9 ear and lateral skull base procedures performed with the use of robotic-assisted surgery. All surgeons underwent surveys to assess the performance and workload of the device compared to the microscope or endoscope. There were no postoperative complications. Robotic-assisted surgery was optimal for providing high image quality, ergonomics, and maintaining surgical performance. The size of the device and mental demand were higher compared to the microscope or endoscope. Robotic-assisted surgery can be an adjuvant to perform otologic and neurotologic surgery.
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Procedimientos Quirúrgicos Otológicos , Procedimientos Quirúrgicos Robotizados , Humanos , Procedimientos Quirúrgicos Robotizados/métodos , Procedimientos Neuroquirúrgicos/métodos , Base del Cráneo/cirugía , Endoscopios , Procedimientos Quirúrgicos Otológicos/métodosRESUMEN
Human cytomegalovirus (HCMV) encodes multiple putative G protein-coupled receptors (GPCRs). US28 functions as a viral chemokine receptor and is expressed during both latent and lytic phases of virus infection. US28 actively promotes cellular migration, transformation, and plays a major role in mediating viral latency and reactivation; however, knowledge about the interaction partners involved in these processes is still incomplete. Herein, we utilized a proximity-dependent biotinylating enzyme (TurboID) to characterize the US28 interactome when expressed in isolation, and during both latent (CD34+ hematopoietic progenitor cells) and lytic (fibroblasts) HCMV infection. Our analyses indicate that the US28 signalosome converges with RhoA and EGFR signal transduction pathways, sharing multiple mediators that are major actors in processes such as cellular proliferation and differentiation. Integral members of the US28 signaling complex were validated in functional assays by immunoblot and small-molecule inhibitors. Importantly, we identified RhoGEFs as key US28 signaling intermediaries. In vitro latency and reactivation assays utilizing primary CD34+ hematopoietic progenitor cells (HPCs) treated with the small-molecule inhibitors Rhosin or Y16 indicated that US28 -RhoGEF interactions are required for efficient viral reactivation. These findings were recapitulated in vivo using a humanized mouse model where inhibition of RhoGEFs resulted in a failure of the virus to reactivate. Together, our data identifies multiple new proteins in the US28 interactome that play major roles in viral latency and reactivation, highlights the utility of proximity-sensor labeling to characterize protein interactomes, and provides insight into targets for the development of novel anti-HCMV therapeutics.
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Citomegalovirus , Transducción de Señal , Animales , Ratones , Humanos , Citomegalovirus/fisiología , Latencia del Virus , Diferenciación Celular , Células Madre HematopoyéticasRESUMEN
Prior work has demonstrated improved accuracy in otitis media diagnosis based on otoscopy using artificial intelligence (AI)-based approaches compared to clinician evaluation. However, this difference in accuracy has not been shown in a setting resembling the point-of-care. In this study, we compare the diagnostic accuracy of a machine-learning model to that of pediatricians using standard handheld otoscopes. We find that the model is more accurate than clinicians (90.6% vs 59.4%, P = .01). This is a step towards validation of AI-based diagnosis under more real-world conditions. With further validation, for example on different patient populations and in deployment, this technology could be a useful addition to the clinician's toolbox in accurately diagnosing otitis media.
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PARPs encompass a small yet pervasive group of 17 enzymes that catalyze a post-translational modification known as ADP-ribosylation. PARP1, the founding member, has received considerable focus; however, in recent years, the spotlight has shifted to other members within the PARP family. In this opinion piece, we first discuss surprising findings that some FDA-approved PARP1 inhibitors activate innate immune signaling in cancer cells that harbor mutations in the DNA repair pathway. We then discuss hot-off-the-press genetic and pharmacological studies that reveal roles for PARP7, PARP11, and PARP14 in immune signaling in both tumor cells and tumor-associated immune cells. We conclude with thoughts on tuning PARP1-inhibitor-mediated innate immune activation and explore the unrealized potential for small molecule modulators of other PARP family members as next-generation immuno-oncology drugs.
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Adenosina Difosfato Ribosa , Poli(ADP-Ribosa) Polimerasas , Poli(ADP-Ribosa) Polimerasas/genética , Poli(ADP-Ribosa) Polimerasas/metabolismo , Adenosina Difosfato Ribosa/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Microambiente Tumoral , Procesamiento Proteico-PostraduccionalRESUMEN
OBJECTIVE: To assess the impact of an education specialist in a multidisciplinary pediatric hearing loss clinic. STUDY DESIGN: Retrospective review and cross-sectional survey. SETTING: Single tertiary care center. METHODS: Consultations held between an education specialist and families of pediatric deaf or hard of hearing (DHH) children within a two-year period were reviewed. Reasons for referral and services provided to each patient and family who subsequently worked with the educational specialist were assessed. Parents of patients who had previously worked with the education specialist were invited to complete a survey evaluating their experience. RESULTS: 102 patients were referred to the educational specialist in a two-year period. Most common reasons for referral included need for special education plans to accommodate their hearing deficit (32) or family request to support for revisions to such plans (37). 14 patient families completed our survey. 76.9 % of respondents confirmed that the education specialist recommended resources they had not been introduced to before. Given a scale of 1 ("completely dissatisfied") and 10 being "completely satisfied," the average rating of the 14 respondents was 9.0. CONCLUSION: The role of an education specialist in a pediatric hearing loss clinic is to optimize patient and family access to resources that could benefit their DHH child's academic development over time. Future studies should prospectively investigate the impact of education specialist services on the educational progress of DHH patients compared to outcomes without these supports.
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Sordera , Pérdida Auditiva , Niño , Humanos , Estudios Retrospectivos , Estudios Transversales , Pérdida Auditiva/terapia , PadresRESUMEN
Relations among behavioral, psychological, and electrophysiological correlates of Linguistic Empathy were examined in two experiments using lateralized stimuli. Linguistic Empathy is defined as a linguistic manifestation of the point of view the speaker assumes toward the content of the utterance, and of the speaker's attitude toward/identification with the referents therein. Linguistic choices made by the speaker among multiple logically and referentially synonymous lexical and grammatical options reveal the speaker's perspectives. In experiment 1, acceptability ratings were measured for Context-Target sentence pairs that did or did not violate two Empathy Hierarchies (Person Empathy Hierarchy and Topic Empathy Hierarchy); the Empathy Quotient (EQ) test of Psychological Empathy was also administered. Ratings were lower for sentence pairs that violated both hierarchies than for those violating neither and were intermediate for sentences violating only one hierarchy. Linguistic Empathy (LE) was operationalized as the difference in ratings between sentences violating both vs. neither empathy hierarchy; this measure correlated positively with EQ. Experiment 2 replicated those results with new participants and measured reaction time and EEG during ratings. While there were no effects of hemisphere or visual field on the linguistic variables, the amplitude of a positive event-related potential deflection at 380 ms provided a partial electrophysiological correlate for LE. Its difference measure correlated with behavioral LE but not with EQ. Though preliminary, these experiments show that Linguistic Empathy may share information processing computations with Psychological Empathy and have an electrophysiological correlate.
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Empatía , Lingüística , Humanos , Lenguaje , Potenciales Evocados/fisiologíaRESUMEN
INTRODUCTION: The COVID-19 pandemic has caused unexpected disruptions in patient care, including adherence to the Early Hearing Detection and Intervention (EHDI) 1-3-6 guidelines. These guidelines mandate newborn hearing screening (NHS) by 1 month of age, diagnosis of hearing loss (HL) by 3 months, and referral to Early Intervention by 6 months. The objective of this study was to investigate the impact of COVID-19 on EHDI benchmarks in a major US city to help clinicians address current needs and prepare for future disruptive events. METHODS: Retrospective review was performed for all patients who did not pass NHS at two tertiary care centers between March 2018 and March 2022. Patients were divided into three cohorts based on the periods of time before, during, and after the COVID-19 Massachusetts State of Emergency (SOE). Demographics, medical history, NHS results, Auditory Brainstem Response results, and hearing aid (HA) intervention data were collected. Two-sampled independent t-tests and analysis of variance were used to compute rate and time outcomes. RESULTS: 30,773 newborns underwent NHS and 678 failed NHS. There was no difference in 1-month benchmark NHS rates, increased 3-month benchmark HL diagnosis rate post-SOE COVID (91.7%; p = 0.002), and increased 6-month benchmark HA intervention rate post-SOE COVID compared to pre-COVID (88.9% vs. 44.4%; p = 0.027). Mean time to NHS was lower during SOE COVID compared to pre-COVID (1.9 days vs. 2.0 days; p = 0.038) and mean time to HL diagnosis was higher during SOE COVID (47.5 days; p < 0.001). Lost to follow-up (LTF) rate at HL diagnosis decreased post-SOE (4.8%; p = 0.008). CONCLUSION: No differences in EHDI 1-3-6 benchmark rates between pre-COVID and SOE COVID patients were observed. However, increased 3-month benchmark HL diagnosis and 6-month benchmark HA intervention rates and a decreased LTF rate at 3-month benchmark HL diagnosis were observed post-SOE COVID.
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COVID-19 , Sordera , Pérdida Auditiva , Recién Nacido , Humanos , Lactante , Pandemias , Tamizaje Neonatal/métodos , Pérdida Auditiva/diagnóstico , Pérdida Auditiva/epidemiología , Pérdida Auditiva/terapia , Pruebas Auditivas/métodos , Prueba de COVID-19RESUMEN
OBJECTIVE: To determine the relationship between hearing loss etiology, cochlear implant (CI) programming levels, and speech perception performance in a large clinical cohort of pediatric CI recipients. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary care hospitals. PATIENTS: A total of 136 pediatric CI recipients (218 ears) were included in this study. All patients had diagnoses of either enlarged vestibular aqueduct (EVA) or GJB2 (Connexin-26) mutation confirmed via radiographic data and/or genetic reports. All patients received audiologic care at either Boston Children's Hospital or Massachusetts Eye and Ear in Boston, MA, between the years 1999 and 2020. MAIN OUTCOME MEASURES: Electrode impedances and programming levels for each active electrode and speech perception scores were evaluated as a function of etiology (EVA or GJB2 mutation). RESULTS: Children with EVA had significantly higher impedances and programming levels (thresholds and upper stimulation levels) than the children with GJB2 mutation. Speech perception scores did not differ as a function of etiology in this sample; rather, they were positively correlated with duration of CI experience (time since implantation). CONCLUSIONS: Differences in electrode impedances and CI programming levels suggest that the electrode-neuron interface varies systematically as a function of hearing loss etiology in pediatric CI recipients with EVA and those with GJB2 mutation. Time with the CI was a better predictor of speech perception scores than etiology, suggesting that children can adapt to CI stimulation with experience.
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Implantación Coclear , Implantes Cocleares , Sordera , Pérdida Auditiva Sensorineural , Percepción del Habla , Acueducto Vestibular , Niño , Humanos , Conexinas/genética , Sordera/genética , Sordera/cirugía , Pérdida Auditiva Sensorineural/cirugía , Mutación , Estudios Retrospectivos , Acueducto Vestibular/cirugíaRESUMEN
Controlled protein synthesis is required to regulate gene expression and is often carried out in a cell type-specific manner. Protein synthesis is commonly measured by labeling the nascent proteome with amino acid analogs or isotope-containing amino acids. These methods have been difficult to implement in vivo as they require lengthy amino acid replacement procedures. O-propargyl-puromycin (OPP) is a puromycin analog that incorporates into nascent polypeptide chains. Through its terminal alkyne, OPP can be conjugated to a fluorophore-azide for directly visualizing nascent protein synthesis, or to a biotin-azide for capture and identification of newly-synthesized proteins. To achieve cell type-specific OPP incorporation, we developed phenylacetyl-OPP (PhAc-OPP), a puromycin analog harboring an enzyme-labile blocking group that can be removed by penicillin G acylase (PGA). Here, we show that cell type-specific PGA expression in Drosophila can be used to achieve OPP labeling of newly-synthesized proteins in targeted cell populations within the brain. Following a brief 2 hr incubation of intact brains with PhAc-OPP, we observe robust imaging and affinity purification of OPP-labeled nascent proteins in PGA-targeted cell populations. We apply this method to show a pronounced age-related decline in neuronal protein synthesis in the fly brain, demonstrating the capability of PhAc-OPP to quantitatively capture in vivo protein synthesis states. This method, which we call POPPi (PGA-dependent OPP incorporation), should be applicable for rapidly visualizing protein synthesis and identifying nascent proteins synthesized under diverse physiological and pathological conditions with cellular specificity in vivo.
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Drosophila , Proteoma , Animales , Proteoma/metabolismo , Drosophila/metabolismo , Azidas/química , Aminoácidos/metabolismo , PuromicinaRESUMEN
OBJECTIVE: To systematically review the literature to determine auditory outcomes of cochlear implantation in children ≤12 months old. DATA SOURCE: PubMed, EMBASE, Medline, CINAHL, Cochrane, Scopus, and Web of Science databases were searched from inception to 9/1/2021 using PRISMA guidelines. REVIEW METHODS: Studies analyzing auditory outcomes after cochlear implantation (CI) in children ≤12 months of age were included. Non-English studies and case reports were excluded. Outcome measures included functional and objective auditory results. Two independent reviewers evaluated each abstract and article. Heterogeneity and bias across studies were evaluated. RESULTS: Of 305 articles identified, 17 met inclusion criteria. There were 642 children ages 2 to 12 months at CI. The most common etiologies of hearing loss were congenital CMV, meningitis, idiopathic hearing loss, and GJB2 mutations and other genetic causes. All studies concluded that early CI was safe. Overall, outcomes improved following early CI: IT-MAIS (9 studies), LittlEARS (4 studies), PTA (3 studies), CAP (3 studies), GASP (3 studies), and LNT (3 studies). Nine studies compared outcomes to an older implantation group (>12 months); of these (n = 450 early CI, n = 1189 late CI), 8 studies showed earlier CI achieved comparable or better auditory outcomes than later implantation, whereas 1 study (n = 120) concluded no differences in speech perception improvement. CONCLUSION: Auditory outcomes were overall improved in children ≤12 months old undergoing CI. Studies that compared early to late CI demonstrated similar or better auditory outcomes in early implantation group. Given the comparable safety profile and critical time period of speech and language acquisition, earlier CI should be considered for infants with hearing loss.
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Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Lactante , Niño , Humanos , Implantación Coclear/métodos , Sordera/cirugía , Desarrollo del Lenguaje , Resultado del TratamientoRESUMEN
This diagnostic study examines the application of generative artificial intelligence in clinical tool research and development.
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Inteligencia Artificial , Membrana Timpánica , Humanos , Membrana Timpánica/diagnóstico por imagenRESUMEN
Synthetic clinical images could augment real medical image datasets, a novel approach in otolaryngology-head and neck surgery (OHNS). Our objective was to develop a generative adversarial network (GAN) for tympanic membrane images and to validate the quality of synthetic images with human reviewers. Our model was developed using a state-of-the-art GAN architecture, StyleGAN2-ADA. The network was trained on intraoperative high-definition (HD) endoscopic images of tympanic membranes collected from pediatric patients undergoing myringotomy with possible tympanostomy tube placement. A human validation survey was administered to a cohort of OHNS and pediatrics trainees at our institution. The primary measure of model quality was the Frechet Inception Distance (FID), a metric comparing the distribution of generated images with the distribution of real images. The measures used for human reviewer validation were the sensitivity, specificity, and area under the curve (AUC) for humans' ability to discern synthetic from real images. Our dataset comprised 202 images. The best GAN was trained at 512x512 image resolution with a FID of 47.0. The progression of images through training showed stepwise "learning" of the anatomic features of a tympanic membrane. The validation survey was taken by 65 persons who reviewed 925 images. Human reviewers demonstrated a sensitivity of 66%, specificity of 73%, and AUC of 0.69 for the detection of synthetic images. In summary, we successfully developed a GAN to produce synthetic tympanic membrane images and validated this with human reviewers. These images could be used to bolster real datasets with various pathologies and develop more robust deep learning models such as those used for diagnostic predictions from otoscopic images. However, caution should be exercised with the use of synthetic data given issues regarding data diversity and performance validation. Any model trained using synthetic data will require robust external validation to ensure validity and generalizability.
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One critical approach for promoting the efficiency of memory is to adopt selective encoding strategies to prioritize more valuable information. Past neuroimaging studies have shown that value-directed modulation of verbal memory depends heavily on the engagement of left-lateralized semantic processing regions, particularly in the ventrolateral prefrontal cortex (VLPFC). In the present study, we used high-definition transcranial direct current stimulation (HD-tDCS) to seek evidence for a causal role of left VLPFC in supporting the memory advantage for high-value items. Three groups of healthy young adult participants were presented with lists of words to remember, with each word accompanied by an arbitrarily assigned point value. During the first session, all participants received sham stimulation as they encoded five lists of 30 words each. Two of these lists were immediately tested with free recall, with feedback given to allow participants to develop metacognitive insight and strategies to maximize their point total. The second session had the exact same structure as the first, but the groups differed in whether they received continued sham stimulation (N = 22) or anodal stimulation of the left VLPFC (N = 21) or right VLPFC (N = 20). Those lists not tested with immediate recall were tested with recognition judgments after a one-day delay. Since no brain stimulation was applied during this Day 2 test, any performance differences can be attributed to the effects of stimulation on Day 1 encoding processes. Anodal stimulation of left VLPFC significantly boosted participants' memory encoding selectivity. In comparison, no such effect was seen in participants who received right VLPFC or sham stimulation. Estimates of recollection- and familiarity-based responding revealed that left VLPFC stimulation specifically amplified the effects of item value on recollection. These results demonstrate a causal role for left VLPFC in the implementation of selective value-directed encoding strategies, putatively by boosting deep semantic processing of high-value words. Our findings also provide further evidence on the hemispheric lateralization of value-directed verbal memory encoding.