Publications by authors named "Leyton C"

Background And Purpose: Nonfluent variant primary progressive aphasia (nfvPPA) is a neurodegenerative disorder characterized by the progressive deterioration of language functions that typically appears with atrophy predominating in the left peri-insular region (left-nfvPPA) on imaging. While both left-dominant and right-dominant presentations have been reported in semantic variant primary progressive aphasia, the other language presentation of frontotemporal dementia, no case series of nfvPPA with predominantly right-sided atrophy of the peri-insular region (right-nfvPPA) have been reported previously. This study explored whether such entities exist and what their clinical features might be.

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Recent findings suggest that immunoradiotherapy (IRT), combining photon radiotherapy (XRT) or proton radiotherapy (PRT) with immune checkpoint blockade, can enhance systemic tumor control. However, the comparative efficacy of XRT and PRT in IRT remains understudied. To address this, we compared outcomes between XRT + αPD1 and PRT + αPD1 in murine αPD1-resistant lung cancer (344SQR).

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Background: Combining interleukin-2 (IL-2) with radiotherapy (RT) and immune checkpoint blockade (ICB) has emerged as a promising approach to address ICB resistance. However, conventional IL-2 cytokine therapy faces constraints owing to its brief half-life and adverse effects. RDB 1462, the mouse ortholog of Nemvaleukin alfa, is an engineered IL-2 with an intermediate affinity that selectively stimulates antitumor CD8 T and NK cells while limiting regulatory T cell expansion.

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Background: The combination of radiotherapy and immunotherapy (immunoradiotherapy) has been increasingly used for treating a wide range of cancers. However, some tumors are resistant to immunoradiotherapy. We have previously shown that MER proto-oncogene tyrosine kinase (MerTK) expressed on macrophages mediates resistance to immunoradiotherapy.

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Objectives: To examine the clinical trajectories and neural correlates of cognitive and emotion processing changes in the non-fluent/agrammatic (nfvPPA) and the logopenic (lvPPA) variants of primary progressive aphasia (PPA).

Design: Observational case-control longitudinal cohort study.

Setting: Research clinic of frontotemporal dementia.

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The combination of radiation therapy (RT) and immunotherapy has emerged as a promising treatment option in oncology. Historically, x-ray radiation (XRT) has been the most commonly used form of RT. However, proton beam therapy (PBT) is gaining recognition as a viable alternative, as it has been shown to produce similar outcomes to XRT while minimizing off-target effects.

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Purpose: Speed and accuracy of lexical access change with healthy ageing and neurodegeneration. While a word's immediate phonological neighbourhood density (i.e.

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The efficacy of immunoradiotherapy consisting of radiation therapy and immune checkpoint blockade relies on effectively promoting the systemic antitumor immune response's activation while simultaneously reducing local factors favoring immune suppression. We previously demonstrated that NBTXR3, a nanoparticle radioenhancer, significantly improved immune responses in a murine anti-PD1-resistant metastatic lung cancer model. We hypothesize that radioactivated-NBTXR3 addition to anti-PD1 and a second-generation anti-CTLA4 could improve treatment effectiveness.

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Background: While improvements in immunoradiotherapy have significantly improved outcomes for cancer patients, this treatment approach has nevertheless proven ineffective at controlling the majority of malignancies. One of the mechanisms of resistance to immunoradiotherapy is that immune cells may be suppressed via the myriad of different immune checkpoint receptors. Therefore, simultaneous blockade of multiple immune checkpoint receptors may enhance the treatment efficacy of immunoradiotherapy.

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Background: The number of biologics among new medication approvals is increasing. Social, political, and economic factors influence access to these expensive medications. Disparities in access to new medications can exacerbate health disparities.

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The Addenbrooke's Cognitive Examination III is a brief cognitive screening tool that is widely used for the detection and monitoring of dementia. Recent findings suggest that the three variants of primary progressive aphasia can be distinguished based on their distinct profiles on the five subdomain scores of this test. Here, we investigated the utility of the Addenbrooke's Cognitive Examination III to differentiate the primary progressive aphasia variants based on their item-by-item performance profiles on this test.

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  • * In a study of 2056 patients, 152 (7.4%) had indeterminate SRA results, which were linked to higher rates of severe thrombocytopenia and greater likelihood of ICU treatment.
  • * Patients with indeterminate results exhibited increased mortality, suggesting that these results may reflect a different platelet activation process unrelated to heparin, rather than hematological issues specifically caused by heparin.
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Objectives: Abnormal beliefs and delusions have been reported in some people with dementia, however, the prevalence of delusions, and their neurocognitive basis has been underexplored. This study aimed to examine the presence, severity, content and neural correlates of delusions in a large, well-characterised cohort of dementia patients using a transdiagnostic, cross-sectional approach.

Methods: Four-hundred and eighty-seven people with dementia were recruited: 102 Alzheimer's disease, 136 behavioural-variant frontotemporal dementia, 154 primary progressive aphasia, 29 motor neurone disease, 46 corticobasal syndrome, 20 progressive supranuclear palsy.

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  • The study investigates the prevalence of amyloid aggregation, a key feature of Alzheimer's disease, in individuals with varying cognitive statuses, including those with normal cognition and who have clinical AD dementia.
  • It analyzes how factors like age, sex, educational background, and the method of detecting amyloid (CSF or PET scans) influence the prevalence estimates.
  • Data were collected from 85 study cohorts between 2013 and 2020, using a systematic approach to categorize amyloid measurements as normal or abnormal.
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Mounting evidence suggests that, in parallel with well-defined changes in language, primary progressive aphasia (PPA) syndromes display co-occurring social cognitive impairments. Here, we explored multidimensional profiles of carer-rated social communication using the La Trobe Communication Questionnaire (LCQ) in 11 semantic dementia (SD), 12 logopenic progressive aphasia (LPA) and 9 progressive non-fluent aphasia (PNFA) cases and contrasted their performance with 19 Alzheimer's disease (AD) cases, 26 behavioural variant frontotemporal dementia (bvFTD) cases and 31 healthy older controls. Relative to the controls, the majority of patient groups displayed significant overall social communication difficulties, with common and unique profiles of impairment evident on the LCQ subscales.

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Aquired apraxia of speech is a disorder that impairs speech production, despite intact peripheral neuromotor function. Its pathomechanism remains to be established. Neurodegenerative lesion models provide an unequalled opportunity to explore the neural correlates of apraxia of speech, which is present in a subset of patients diagnosed with non-semantic variants of primary progressive aphasia.

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  • The study looked at how heart failure (HF) affects COVID-19 patients admitted to the hospital.
  • It found that patients with HF were more likely to die from COVID-19 compared to those without HF, with a death rate of 49% versus 27%.
  • The researchers concluded that having HF makes COVID-19 patients more at risk for serious outcomes and higher chances of dying in the hospital.
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  • The study examines the mental health differences between indigenous (Aymara and Mapuche) and non-indigenous older adults in rural Chile, focusing on depression, loneliness, and personal well-being.
  • Indigenous participants showed lower levels of depression and loneliness and higher personal well-being compared to non-indigenous individuals.
  • The research suggests that living in native rural environments may provide protective benefits for indigenous peoples due to cultural continuity and resilience against socio-economic challenges.
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Introduction: Six patients with equivocal amyloid-PET results are discussed.

Methods: Patients underwent clinical/neuropsychological assessment, MRI, and amyloid-PET. Equivocal amyloid-PET was defined as cortical ligand binding with SUVR < 1.

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: Multiple national organizations have identified a need to incorporate more evidence-based medicine in emergency medical services (EMS) through the creation of evidence-based guidelines (EBGs). Tools like the Appraisal of Guidelines for Research and Evaluation (AGREE) II and criteria outlined by the National Academy of Medicine (NAM) have established concrete recommendations for the development of high-quality guidelines. While many guidelines have been created that address topics within EMS medicine, neither the quantity nor quality of prehospital EBGs have been previously reported.

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Background: The Centiloid scale was developed to standardise the results of beta-amyloid (Aβ) PET. We aimed to determine the Centiloid unit (CL) thresholds for CERAD sparse and moderate-density neuritic plaques, Alzheimer's disease neuropathologic change (ADNC) score of intermediate or high probability of Alzheimer's Disease (AD), final clinicopathological diagnosis of AD, and expert visual read of a positive Aβ PET scan.

Methods: Aβ PET results in CL for 49 subjects were compared with post-mortem findings, visual read, and final clinicopathological diagnosis.

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To track neural correlates of naming performance with disease progression, we estimated key areas affected in nonfluent/agrammatic (nfvPPA) and logopenic (lvPPA) primary progressive aphasia variants over time and changes in naming correlates over time. Twenty-nine non-semantic PPA participants (17 nfvPPA and 12 lvPPA) were selected based upon current diagnostic criteria and PiB-PET status and conducted a confrontation-naming task and a structural MRI. Linear mixed-effect models implemented in FreeSurfer were used for tracking cortical thickness and epicenters of atrophy over time.

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Objective: To estimate the prevalence of amyloid positivity, defined by positron emission tomography (PET)/cerebrospinal fluid (CSF) biomarkers and/or neuropathological examination, in primary progressive aphasia (PPA) variants.

Methods: We conducted a meta-analysis with individual participant data from 1,251 patients diagnosed with PPA (including logopenic [lvPPA, n = 443], nonfluent [nfvPPA, n = 333], semantic [svPPA, n = 401], and mixed/unclassifiable [n = 74] variants of PPA) from 36 centers, with a measure of amyloid-β pathology (CSF [n = 600], PET [n = 366], and/or autopsy [n = 378]) available. The estimated prevalence of amyloid positivity according to PPA variant, age, and apolipoprotein E (ApoE) ε4 status was determined using generalized estimating equation models.

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