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1.
Neural Regen Res ; 20(6): 1644-1664, 2025 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-39104096

RESUMEN

Traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease are three distinct neurological disorders that share common pathophysiological mechanisms involving neuroinflammation. One sequela of neuroinflammation includes the pathologic hyperphosphorylation of tau protein, an endogenous microtubule-associated protein that protects the integrity of neuronal cytoskeletons. Tau hyperphosphorylation results in protein misfolding and subsequent accumulation of tau tangles forming neurotoxic aggregates. These misfolded proteins are characteristic of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease and can lead to downstream neuroinflammatory processes, including assembly and activation of the inflammasome complex. Inflammasomes refer to a family of multimeric protein units that, upon activation, release a cascade of signaling molecules resulting in caspase-induced cell death and inflammation mediated by the release of interleukin-1ß cytokine. One specific inflammasome, the NOD-like receptor protein 3, has been proposed to be a key regulator of tau phosphorylation where it has been shown that prolonged NOD-like receptor protein 3 activation acts as a causal factor in pathological tau accumulation and spreading. This review begins by describing the epidemiology and pathophysiology of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease. Next, we highlight neuroinflammation as an overriding theme and discuss the role of the NOD-like receptor protein 3 inflammasome in the formation of tau deposits and how such tauopathic entities spread throughout the brain. We then propose a novel framework linking traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease as inflammasome-dependent pathologies that exist along a temporal continuum. Finally, we discuss potential therapeutic targets that may intercept this pathway and ultimately minimize long-term neurological decline.

2.
Brain Lang ; 257: 105459, 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39241469

RESUMEN

Transcranial direct current stimulation (tDCS) targeting Broca's area has shown promise for augmenting language production in post-stroke aphasia (PSA). However, previous research has been limited by small sample sizes and inconsistent outcomes. This study employed a double-blind, parallel, randomized, controlled design to evaluate the efficacy of anodal Broca's tDCS, paired with 20-minute speech and language therapy (SLT) focused primarily on expressive language, across 5 daily sessions in 45 chronic PSA patients. Utilizing the Western Aphasia Battery-Revised, which assesses a spectrum of linguistic abilities, we measured changes in both expressive and receptive language skills before and after intervention. The tDCS group demonstrated significant improvements over sham in aphasia quotient, auditory verbal comprehension, and spontaneous speech. Notably, tDCS improved both expressive and receptive domains, whereas sham only benefited expression. These results underscore the broader linguistic benefits of Broca's area stimulation and support the integration of tDCS with SLT to advance aphasia rehabilitation.

3.
bioRxiv ; 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39253459

RESUMEN

Antigenic variation, using large genomic repertoires of antigen-encoding genes, allows pathogens to evade host antibody. Many pathogens, including the African trypanosome Trypanosoma brucei, extend their antigenic repertoire through genomic diversification. While evidence suggests that T. brucei depends on the generation of new variant surface glycoprotein (VSG) genes to maintain a chronic infection, a lack of experimentally tractable tools for studying this process has obscured its underlying mechanisms. Here, we present a highly sensitive targeted sequencing approach for measuring VSG diversification. Using this method, we demonstrate that a Cas9-induced DNA double-strand break within the VSG coding sequence can induce VSG recombination with patterns identical to those observed during infection. These newly generated VSGs are antigenically distinct from parental clones and thus capable of facilitating immune evasion. Together, these results provide insight into the mechanisms of VSG diversification and an experimental framework for studying the evolution of antigen repertoires in pathogenic microbes.

4.
EBioMedicine ; 108: 105310, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39293212

RESUMEN

BACKGROUND: The inflammatory response in patients with traumatic brain injury (TBI) offers opportunities for stratification and intervention. Previous unselected approaches to immunomodulation in patients with TBI have not improved patient outcomes. METHODS: Serum and plasma samples from two prospective, multi-centre observational studies of patients with TBI were used to discover (Collaborative European NeuroTrauma Effectiveness Research [CENTER-TBI], Europe) and validate (Transforming Research and Clinical Knowledge in Traumatic Brain Injury [TRACK-TBI] Pilot, USA) individual variations in the immune response using a multiplex panel of 30 inflammatory mediators. Mediators that were associated with unfavourable outcomes (Glasgow outcome score-extended [GOS-E] ≤ 4) were used for hierarchical clustering to identify patients with similar signatures. FINDINGS: Two clusters were identified in both the discovery and validation cohorts, termed early-inflammatory and pauci-inflammatory. The early-inflammatory phenotype had higher concentrations of interleukin-6 (IL-6), IL-15, and monocyte chemoattractant protein 1 (MCP1). Patients with the early-inflammatory phenotype were older and more likely to have an unfavourable GOS-E at 6 months. There were no differences in the baseline injury severity scores between patients in each phenotype. A combined IL-15 and MCP1 signature identified patients with the early-inflammatory phenotype in both cohorts. Inflammatory processes mediated outcomes in older patients with moderate-severe TBI. INTERPRETATION: Our findings offer a precision medicine approach for future clinical trials of immunomodulation in patients with TBI, by using inflammatory signatures to stratify patients. FUNDING: CENTER-TBI study was supported by the European Union 7th Framework Programme. TRACK-TBI is supported by the National Institute of Neurological Disorders and Stroke.

5.
Cancer Cell ; 42(9): 1582-1597.e10, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39214097

RESUMEN

Combination checkpoint blockade with anti-PD-1 and anti-CTLA-4 antibodies has shown promising efficacy in melanoma. However, the underlying mechanism in humans remains unclear. Here, we perform paired single-cell RNA and T cell receptor (TCR) sequencing across time in 36 patients with stage IV melanoma treated with anti-PD-1, anti-CTLA-4, or combination therapy. We develop the algorithm Cyclone to track temporal clonal dynamics and underlying cell states. Checkpoint blockade induces waves of clonal T cell responses that peak at distinct time points. Combination therapy results in greater magnitude of clonal responses at 6 and 9 weeks compared to single-agent therapies, including melanoma-specific CD8+ T cells and exhausted CD8+ T cell (TEX) clones. Focused analyses of TEX identify that anti-CTLA-4 induces robust expansion and proliferation of progenitor TEX, which synergizes with anti-PD-1 to reinvigorate TEX during combination therapy. These next generation immune profiling approaches can guide the selection of drugs, schedule, and dosing for novel combination strategies.


Asunto(s)
Linfocitos T CD8-positivos , Antígeno CTLA-4 , Inhibidores de Puntos de Control Inmunológico , Melanoma , Receptor de Muerte Celular Programada 1 , Humanos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Receptor de Muerte Celular Programada 1/inmunología , Melanoma/tratamiento farmacológico , Melanoma/inmunología , Inhibidores de Puntos de Control Inmunológico/farmacología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Antígeno CTLA-4/antagonistas & inhibidores , Antígeno CTLA-4/inmunología , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Receptores de Antígenos de Linfocitos T/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Femenino , Análisis de la Célula Individual/métodos , Masculino
6.
Arthroscopy ; 40(6): 1727-1736.e1, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38949274

RESUMEN

PURPOSE: To categorize and trend annual out-of-pocket expenditures for arthroscopic rotator cuff repair (RCR) patients relative to total healthcare utilization (THU) reimbursement and compare drivers of patient out-of-pocket expenditures (POPE) in a granular fashion via analyses by insurance type and surgical setting. METHODS: Patients who underwent outpatient arthroscopic RCR in the United States from 2013 to 2018 were identified from the IBM MarketScan Database. Primary outcome variables were total POPE and THU reimbursement, which were calculated for all claims in the 9-month perioperative period. Trends in outcome variables over time and differences across insurance types were analyzed. Multivariable analysis was performed to investigate drivers of POPE. RESULTS: A total of 52,330 arthroscopic RCR patients were identified. Between 2013 and 2018, median POPE increased by 47.5% ($917 to $1,353), and median THU increased by 9.3% ($11,964 to $13,076). Patients with high deductible insurance plans paid $1,910 toward their THU, 52.5% more than patients with preferred provider plans ($1,253, P = .001) and 280.5% more than patients with managed care plans ($502, P = .001). All components of POPE increased over the study period, with the largest observed increase being POPE for the immediate procedure (P = .001). On multivariable analysis, out-of-network facility, out-of-network surgeon, and high-deductible insurance most significantly increased POPE. CONCLUSIONS: POPE for arthroscopic RCR increased at a higher rate than THU over the study period, demonstrating that patients are paying an increasing proportion of RCR costs. A large percentage of this increase comes from increasing POPE for the immediate procedure. Out-of-network facility status increased POPE 3 times more than out-of-network surgeon status, and future cost-optimization strategies should focus on facility-specific reimbursements in particular. Last, ambulatory surgery centers (ASCs) significantly reduced POPE, so performing arthroscopic RCRs at ASCs is beneficial to cost-minimization efforts. CLINICAL RELEVANCE: This study highlights that although payers have increased reimbursement for RCR, patient out-of-pocket expenditures have increased at a much higher rate. Furthermore, this study elucidates trends in and drivers of patient out-of-pocket payments for RCR, providing evidence for development of cost-optimization strategies and counseling of patients undergoing RCR.


Asunto(s)
Artroscopía , Gastos en Salud , Lesiones del Manguito de los Rotadores , Humanos , Artroscopía/economía , Masculino , Femenino , Gastos en Salud/estadística & datos numéricos , Persona de Mediana Edad , Estados Unidos , Lesiones del Manguito de los Rotadores/cirugía , Lesiones del Manguito de los Rotadores/economía , Procedimientos Quirúrgicos Ambulatorios/economía , Reembolso de Seguro de Salud , Aceptación de la Atención de Salud/estadística & datos numéricos , Anciano , Manguito de los Rotadores/cirugía
7.
Int J Surg Case Rep ; 121: 109947, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38964234

RESUMEN

INTRODUCTION AND IMPORTANCE: Society of thoracic surgery (STS) risk score has been used as a tool to gauge operative risk of cardiac surgery patients. High-risk patients, with STS risk score > 8 %, are considered as having prohibitive risk and are not offered surgery. There is no established strategy to minimize postoperative hemodynamic instability using mechanical circulatory support (MCS), despite growing interest in utilizing MCS prior to hemodynamic instability. The Impella 5.5 can provide enough perfusion and unload the left ventricle. CASE PRESENTATION: We managed a 75-year-old male with multiple comorbidities and a presumed Society of Thoracic Surgeons (STS) score higher than 9.8 %, who had redo coronary artery bypass grafting and aortic and mitral valve replacement with concomitant implantation of the Impella 5.5. Patient had a good recovery despite developing post-operative atrial fibrillation. DISCUSSION: Impella is used as a mechanical circulatory support device in patients with cardiogenic shock. It provides forward flow and effectively unloads the left ventricle. The concomitant placement of the Impella 5.5 in high-risk cardiac candidates may be associated with reduced operative risk. CONCLUSION: Placement of the device as part of surgical plan can potentially mitigate the perioperative risk by providing adequate endogean perfusion, decrease pressor support, unloading LV.

8.
Nat Commun ; 15(1): 6305, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39060305

RESUMEN

Ionizable lipid nanoparticles (LNPs) are seeing widespread use in mRNA delivery, notably in SARS-CoV-2 mRNA vaccines. However, the expansion of mRNA therapies beyond COVID-19 is impeded by the absence of LNPs tailored for diverse cell types. In this study, we present the AI-Guided Ionizable Lipid Engineering (AGILE) platform, a synergistic combination of deep learning and combinatorial chemistry. AGILE streamlines ionizable lipid development with efficient library design, in silico lipid screening via deep neural networks, and adaptability to diverse cell lines. Using AGILE, we rapidly design, synthesize, and evaluate ionizable lipids for mRNA delivery, selecting from a vast library. Intriguingly, AGILE reveals cell-specific preferences for ionizable lipids, indicating tailoring for optimal delivery to varying cell types. These highlight AGILE's potential in expediting the development of customized LNPs, addressing the complex needs of mRNA delivery in clinical practice, thereby broadening the scope and efficacy of mRNA therapies.


Asunto(s)
COVID-19 , Aprendizaje Profundo , Nanopartículas , ARN Mensajero , SARS-CoV-2 , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Mensajero/administración & dosificación , Humanos , SARS-CoV-2/genética , Nanopartículas/química , Lípidos/química , Técnicas de Transferencia de Gen , Vacunas contra la COVID-19 , Vacunas de ARNm , Línea Celular , Técnicas Químicas Combinatorias , Liposomas
9.
Nat Chem ; 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38858518

RESUMEN

Adding synthetic nucleotides to DNA increases the linear information density of DNA molecules. Here we report that it also can increase the diversity of their three-dimensional folds. Specifically, an additional nucleotide (dZ, with a 5-nitro-6-aminopyridone nucleobase), placed at twelve sites in a 23-nucleotides-long DNA strand, creates a fairly stable unimolecular structure (that is, the folded Z-motif, or fZ-motif) that melts at 66.5 °C at pH 8.5. Spectroscopic, gel and two-dimensional NMR analyses show that the folded Z-motif is held together by six reverse skinny dZ-:dZ base pairs, analogous to the crystal structure of the free heterocycle. Fluorescence tagging shows that the dZ-:dZ pairs join parallel strands in a four-stranded compact down-up-down-up fold. These have two possible structures: one with intercalated dZ-:dZ base pairs, the second without intercalation. The intercalated structure would resemble the i-motif formed by dC:dC+-reversed pairing at pH ≤ 6.5. This fZ-motif may therefore help DNA form compact structures needed for binding and catalysis.

10.
Arthroscopy ; 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38925232

RESUMEN

PURPOSE: To evaluate the cost-utility of a balloon spacer implant relative to partial repair (PR) for the surgical treatment of full-thickness massive rotator cuff tears (MRCTs). METHODS: A decision-analytic model comparing balloon spacer with PR was developed using data from a prospective, randomized, single-blinded, multicenter-controlled trial of 184 randomized patients. Our model was constructed on the basis of the various event pathways a patient could have after the procedure. The probability that each patient progressed to a given outcome and the quality-adjusted life years (QALY) associated with each outcome were derived from the clinical trial data. Incremental cost utility ratio (ICUR) and incremental net monetary benefit were calculated on the basis of a probabilistic sensitivity analysis using Monte Carlo simulations of 1,000 hypothetical patients progressing through the decision-analytic model. One-way sensitivity and threshold analyses were performed by varying cost, event probability, and QALY estimates. RESULTS: The balloon spacer had an ICUR of $106,851 (95% confidence interval $96,317-$119,143) relative to PR for surgical treatment of MRCT. Across all patients, the balloon spacer was associated with greater 2-year QALY gain compared with PR (0.20 ± 0.02 for balloon spacer vs 0.18 ± 0.02 for PR), but with substantially greater total 2-year cost ($9,701 ± $939 for balloon spacer vs $6,315 ± $627 for PR). PR was associated with a positive incremental net monetary benefit of $1,802 (95% confidence interval $1,653-$1,951) over balloon spacer at the $50,000/QALY willingness-to-pay threshold. CONCLUSIONS: Compared with PR, the balloon spacer is an "intermediate-value" innovation for treatment of MRCT over a 2-year postoperative period with an ICUR value that falls within the $50,000 to $150,000 willingness-to-pay threshold. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38758056

RESUMEN

OBJECTIVE: Identification of biomarkers of cognitive recovery after traumatic brain injury (TBI) will inform care and improve outcomes. This study assessed the utility of neurofilament (NF-L and pNF-H), a marker of neuronal injury, informing cognitive performance following moderate-to-severe TBI (msTBI). SETTING: Level 1 trauma center and outpatient via postdischarge follow-up. PARTICIPANTS: N = 94. Inclusion criteria: Glasgow Coma Scale score less than 13 or 13-15 with clinical evidence of moderate-to-severe injury traumatic brain injury on clinical imaging. Exclusion criteria: neurodegenerative condition, brain death within 3 days after injury. DESIGN: Prospective observational study. Blood samples were collected at several time points post-injury. Cognitive testing was completed at 6 months post-injury. MAIN MEASURES: Serum NF-L (Human Neurology 4-Plex B) pNF-H (SR-X) as measured by SIMOA Quanterix assay. Divided into 3 categorical time points at days post-injury (DPI): 0-15 DPI, 16-90 DPI, and >90 DPI. Cognitive composite comprised executive functioning measures derived from 3 standardized neuropsychological tests (eg, Delis-Kaplan Executive Function System: Verbal Fluency, California Verbal Learning Test, Second Edition, Wechsler Adult Intelligence Scale, Third Edition). RESULTS: pNF-H at 16-90 DPI was associated with cognitive outcomes including a cognitive-executive composite score at 6 months (ß = -.430, t34 = -3.190, P = .003). CONCLUSIONS: Results suggest that "subacute" elevation of serum pNF-H levels may be associated with protracted/poor cognitive recovery from msTBI and may be a target for intervention. Interpretation is limited by small sample size and including only those who were able to complete cognitive testing.

12.
bioRxiv ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38766104

RESUMEN

Regulation of gene expression hinges on the interplay between enhancers and promoters, traditionally explored through pairwise analyses. Recent advancements in mapping genome folding, like GAM, SPRITE, and multi-contact Hi-C, have uncovered multi-way interactions among super-enhancers (SEs), spanning megabases, yet have not measured their frequency in single cells or the relationship between clustering and transcription. To close this gap, here we used multiplexed imaging to map the 3D positions of 376 SEs across thousands of mammalian nuclei. Notably, our single-cell images reveal that while SE-SE contacts are rare, SEs often form looser associations we termed "communities". These communities, averaging 4-5 SEs, assemble cooperatively under the combined effects of genomic tethers, Pol2 clustering, and nuclear compartmentalization. Larger communities are associated with more frequent and larger transcriptional bursts. Our work provides insights about the SE interactome in single cells that challenge existing hypotheses on SE clustering in the context of transcriptional regulation.

13.
Neurol Clin Pract ; 14(4): e200304, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38808025

RESUMEN

Background and Objectives: Presentation, progression, and treatment of Parkinson disease (PD) can differ based on sex and gender. However, knowledge on PD is limited by the characteristics of research participants, and most of the participants are men. In this study, we aimed to identify the attitudes toward and barriers to research participation for people with PD (PwP) based on their sexual orientation and gender identity. Methods: Data were obtained from the Fox Insight on March 16, 2023, for PwP who completed the Attitudes and Beliefs Regarding Research and Genetic Testing for PD. Responses were compared between sexual and gender minorities (SGM) (n = 136), cisgender heterosexual women (n = 1,479), and cisgender heterosexual men (n = 1,445). Associations between age, socioeconomic variables, and the responses that differed between the groups were assessed with linear models. Results: More than 68% of the participants were willing to participate in research; only 43.7% heard about research opportunities, and 52.3% knew where to find a study. Approximately 86.8% of the participants reported hearing about a study from their doctor would make them more likely to participate. A higher percentage of SGM were concerned about transportation and researchers not understanding or respecting their beliefs; a higher percentage of cisgender heterosexual women were concerned about transportation, data privacy, and their family's reaction to genetic results; and a higher percentage of cisgender heterosexual men were concerned about time required for research activities and complex forms. Age and socioeconomic variables were significantly associated with approach toward research that differed between the groups. Discussion: PwP are willing to participate in research, and health care providers can facilitate their participation. Barriers to research participation related to sexual and gender identity exist and must be addressed to increase our understanding of PD in underrepresented populations.

14.
Arthroscopy ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38735415

RESUMEN

PURPOSE: To evaluate a large cross-sectional sample of patients utilizing administrative database records and analyze the effects of income, insurance type, and education level on outcomes after hip arthroscopy, including 2-year revision surgery, conversion to total hip arthroplasty (THA), and 90-day hospitalizations. METHODS: Current Procedural Terminology codes were used to query the PearlDiver Mariner database from October 2015 to January 2020 for patients undergoing hip arthroscopy with a minimum 2-year follow-up. Patients were categorized by mean family income in their zip code of residence (MFIR), health insurance type, and educational attainment in their zip code of residence (EAR). Two-year revision arthroscopy, conversion to THA, and 90-day hospital readmissions or emergency department (ED) visits were analyzed along socioeconomic strata. RESULTS: Multivariate analysis of 33,326 patients revealed that patients with MFIR between $30,000 and $70,000 had lower odds of 2-year revision arthroscopy (odds ratio [OR], 0.63; P < .001), THA conversion (OR, 0.76; P = .050), and 90-day readmission (OR, 0.53; P = .007) compared to MFIR >$100,000. Compared to patients with commercial insurance, patients with Medicare had lower odds of revision arthroscopy (OR, 0.60; P = .035) and THA conversion (OR, 0.46, P < .001) but greater odds of 90-day readmission (OR, 1.74; P = .007). Patients with Medicaid had higher odds of 90-day ED visits (OR, 1.84; P < .001). Patients with low EAR had higher odds of revision arthroscopy (OR, 1.42; P = .005) and THA conversion (OR, 1.58; P = .002) compared to those with high EAR. CONCLUSIONS: Following hip arthroscopy, patients residing in areas with lower mean family income were less likely to undergo reoperations and readmissions. Medicare patients showed lower reoperation but higher readmission odds, while Medicaid patients showed higher odds of ED visits. Additionally, higher educational attainment in the zip code of residence is protective against future reoperation. LEVEL OF EVIDENCE: Level III, retrospective case series.

15.
Cureus ; 16(4): e58768, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38779236

RESUMEN

The clinical Warburg effect is a rare occurrence in cancer biology where tumor cells primarily utilize glycolysis for energy production, leading to significant hypoglycemia and lactate formation. This presentation is associated with a poor prognosis for the patient. In this context, we describe the case of a 53-year-old woman with stage IV mantle cell lymphoma who developed the clinical Warburg effect with solely arrhythmia and without neurological symptoms. She received prompt treatment for glucose stabilization and underwent inpatient chemotherapy. This case underscores the importance of early intervention to reduce tumor burden and highlights the effectiveness of hemodialysis in stabilizing metabolic acidosis. Further investigation into this approach is warranted.

16.
bioRxiv ; 2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38766135

RESUMEN

Humans can remember specific events without acting on them and can influence which memories are retrieved based on internal goals. However, current animal models of memory typically present sensory cues to trigger retrieval and assess retrieval based on action 1-5 . As a result, it is difficult to determine whether measured patterns of neural activity relate to the cue(s), the retrieved memory, or the behavior. We therefore asked whether we could develop a paradigm to isolate retrieval-related neural activity in animals without retrieval cues or the requirement of a behavioral report. To do this, we focused on hippocampal "place cells." These cells primarily emit spiking patterns that represent the animal's current location (local representations), but they can also generate representations of previously visited locations distant from the animal's current location (remote representations) 6-13 . It is not known whether animals can deliberately engage specific remote representations, and if so, whether this engagement would occur during specific brain states. So, we used a closed-loop neurofeedback system to reward expression of remote representations that corresponded to uncued, experimenter-selected locations, and found that rats could increase the prevalence of these specific remote representations over time; thus, demonstrating memory retrieval modulated by internal goals in an animal model. These representations occurred predominately during periods of immobility but outside of hippocampal sharp-wave ripple (SWR) 13-15 events. This paradigm enables future direct studies of memory retrieval mechanisms in the healthy brain and in models of neurological disorders.

19.
J Neurotrauma ; 41(13-14): 1609-1627, 2024 07.
Artículo en Inglés | MEDLINE | ID: mdl-38588256

RESUMEN

Neurofilament-light chain (NF-L) and phosphorylated neurofilament-heavy chain (pNF-H) are axonal proteins that have been reported as potential diagnostic and prognostic biomarkers in traumatic brain injury (TBI). However, detailed temporal profiles for these proteins in blood, and interrelationships in the acute and chronic time periods post-TBI have not been established. Our objectives were: 1) to characterize acute-to-chronic serum NF-L and pNF-H profiles after moderate-severe TBI, as well as acute cerebrospinal fluid (CSF) levels; 2) to evaluate CSF and serum NF-L and pNF-H associations with each other; and 3) to assess biomarker associations with global patient outcome using both the Glasgow Outcome Scale-Extended (GOS-E) and Disability Rating Scale (DRS). In this multi-cohort study, we measured serum and CSF NF-L and pNF-H levels in samples collected from two clinical cohorts (University of Pittsburgh [UPITT] and Baylor College of Medicine [BCM]) of individuals with moderate-severe TBI. The UPITT cohort includes 279 subjects from an observational cohort study; we obtained serum (n = 277 unique subjects) and CSF (n = 95 unique subjects) daily for 1 week, and serum every 2 weeks for 6 months. The BCM cohort included 103 subjects from a previous randomized clinical trial of erythropoietin and blood transfusion threshold after severe TBI, which showed no effect on neurological outcome between treatment arms; serum (n = 99 unique subjects) and CSF (n = 54 unique subjects) NF-L and pNF-H levels were measured at least daily during Days (D) 0-10 post-injury. GOS-E and DRS were assessed at 6 months (both cohorts) and 12 months (UPITT cohort only). Results show serum NF-L and pNF-H gradually rise during the first 10 days and peak at D20-30 post-injury. In the UPITT cohort, acute (D0-6) NF-L and pNF-H levels correlate within CSF and serum (Spearman r = 0.44-0.48; p < 0.05). In the UPITT cohort, acute NF-L CSF and serum levels, as well as chronic (Months [M]2-6) serum NF-L levels, were higher among individuals with unfavorable GOS-E and worse DRS at 12 months (p < 0.05, all comparisons). In the BCM cohort, higher acute serum NF-L levels were also associated with unfavorable GOS-E. Higher pNF-H serum concentrations (D0-6 and M2-6), but not CSF pNF-H, were associated with unfavorable GOS-E and worse DRS (p < 0.05, all comparisons) in the UPITT cohort. Relationships between biomarker levels and favorable outcome persisted after controlling for age, sex, and Glasgow Coma Scale. This study shows for the first time that serum levels of NF-L and pNF-H peak at D20-30 post-TBI. Serum NF-L levels, and to a lesser extent pNF-H levels, are robustly associated with global patient outcomes and disability after moderate-severe TBI. Further studies on clinical utility as prognosis and treatment-response indicators are needed.


Asunto(s)
Biomarcadores , Lesiones Traumáticas del Encéfalo , Proteínas de Neurofilamentos , Humanos , Proteínas de Neurofilamentos/líquido cefalorraquídeo , Proteínas de Neurofilamentos/sangre , Masculino , Femenino , Adulto , Lesiones Traumáticas del Encéfalo/líquido cefalorraquídeo , Lesiones Traumáticas del Encéfalo/sangre , Lesiones Traumáticas del Encéfalo/diagnóstico , Biomarcadores/sangre , Biomarcadores/líquido cefalorraquídeo , Persona de Mediana Edad , Estudios de Cohortes , Fosforilación , Adulto Joven , Escala de Consecuencias de Glasgow , Anciano , Lesión Axonal Difusa/líquido cefalorraquídeo , Lesión Axonal Difusa/sangre
20.
IEEE Trans Neural Netw Learn Syst ; 35(9): 11817-11828, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38687671

RESUMEN

The proliferation of Internet-of-Things (IoT) technologies in modern smart society enables massive data exchange for offering intelligent services. It becomes essential to ensure secure communications while exchanging highly sensitive IoT data efficiently, which leads to high demands for lightweight models or algorithms with limited computation capability provided by individual IoT devices. In this study, a graph representation learning model, which seamlessly incorporates graph neural network (GNN) and knowledge distillation (KD) techniques, named reconstructed graph with global-local distillation (RG-GLD), is designed to realize the lightweight anomaly detection across IoT communication networks. In particular, a new graph network reconstruction strategy, which treats data communications as nodes in a directed graph while edges are then connected according to two specifically defined rules, is devised and applied to facilitate the graph representation learning in secure and efficient IoT communications. Both the structural and traffic features are then extracted from the graph data and flow data respectively, based on the graph attention network (GAT) and multilayer perceptron (MLP) techniques. These can benefit the GNN-based KD process in accordance with the more effective feature fusion and representation, considering both structural and data levels across the dynamic IoT networks. Furthermore, a lightweight local subgraph preservation mechanism improved by the graph attention mechanism and downsampling scheme to better utilize the topological information, and a so-called global information alignment defined based on the self-attention mechanism to effectively preserve the global information, are developed and incorporated in a refined graph attention based KD scheme. Compared with four different baseline methods, experiments and evaluations conducted based on two public datasets demonstrate the usefulness and effectiveness of our proposed model in improving the efficiency of knowledge transfer with higher classification accuracy but lower computational load, which can be deployed for lightweight anomaly detection in sustainable IoT computing environments.

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