Publications by authors named "Gaynor L"

Importance: "SuperAgers" are oldest-old adults (ages 80+) whose memory performance resembles that of adults in their 50s to mid-60s. Factors underlying their exemplary memory are underexplored in large, racially diverse cohorts.

Objective: To determine the frequency of genotypes in non-Hispanic Black and non-Hispanic White SuperAgers compared to middle-aged (ages 50-64), old (ages 65-79), and oldest-old (ages 80+) controls and Alzheimer's disease (AD) dementia cases.

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Oncogenic mutations that drive colorectal cancer can be present in healthy intestines for long periods without overt consequence. Mutation of Adenomatous polyposis coli (Apc), the most common initiating event in conventional adenomas, activates Wnt signalling, hence conferring fitness on mutant intestinal stem cells (ISCs). Apc mutations may occur in ISCs that arose by routine self-renewal or by dedifferentiation of their progeny.

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Subjective cognitive concerns (SCC) are common even in cognitively normal older adults who lack objectively-detectable deficits on standard neuropsychological evaluation. The clinical relevance of these concerns, particularly considering the nature of concerns (e.g.

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Background And Objectives: Cavum septum pellucidum (CSP) is a common but nonspecific MRI finding in individuals with prior head trauma. The type and extent of head trauma related to CSP, CSP features specific to head trauma, and the impact of brain atrophy on CSP are unknown. We evaluated CSP cross-sectionally and longitudinally in healthy and clinically impaired older adults who underwent detailed lifetime head trauma characterization.

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Introduction: C9orf72 expansion is the most common genetic abnormality in behavioral variant frontotemporal dementia (bvFTD) and amyotrophic lateral sclerosis. Although psychiatric prodromes are common in C9orf72 expansion carriers, there are only scattered reported cases of primary psychiatric disorders, such as bipolar disorder, diagnosed at disease onset. Moreover, C9orf72 carrier status is rarely identified in bipolar disorder genetic studies.

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Article Synopsis
  • Traumatic encephalopathy syndrome (TES) is linked to repetitive head impacts and presents cognitive symptoms similar to Alzheimer's disease (AD), complicating diagnosis due to overlapping neuropathological features.
  • A study of 154 participants compared cognitive performance, brain volume, and plasma biomarkers among those with TES, AD, and healthy controls, revealing that Aβ[+] TES patients performed worse on specific cognitive tests compared to Aβ[-] TES patients.
  • Results showed that both Aβ[+] and Aβ[-] TES groups had lower brain volumes in certain areas than healthy controls, but their volumes were similar to those of AD patients; additionally, Aβ[+] TES had higher levels of specific plasma biomarkers.
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Health benefits of physical activity (PA) are well known; however, specific PA patterns that relate most strongly to cognitive aging outcomes are poorly understood. We characterized latent profiles of PA among older adults and examined associations with cognition and vascular burden. 124 functionally normal older adults wore a Fitbit™ for 30 days.

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Age-related cognitive decline is related to cellular and systems-level disruptions across multiple brain regions. Because age-related cellular changes within different structures do not show the same patterns of dysfunction, interventions aimed at optimizing function of large-scale brain networks may show greater efficacy at improving cognitive outcomes in older adults than traditional pharmacotherapies. The current study aimed to leverage a preclinical rat model of aging to determine whether cognitive training in young and aged male rats with a computerized paired-associates learning (PAL) task resulted in changes in global resting-state functional connectivity.

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Objective: Chronic stress adversely affects cognition, in part due to stress-induced inflammation. Rodent models suggest females are more resilient against stress-related cognitive dysfunction than males; however, few studies have examined this in humans. We examined sex differences in the relationship between perceived stress, cognitive functioning, and peripheral inflammation over time among cognitively normal older adults.

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Objective: High quality and accessible education is crucial to secure the future of neuropsychology. Recent and ongoing advancements include the creation of a taxonomy of education and training, progress in delineating relevant competencies, and an update to the Houston Conference Guidelines. Meanwhile, there is also potential for growth in digital methods of delivering education such as podcasts, webinars, and social media platforms.

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Background: As global populations age, cross-national comparisons of cognitive health and dementia risk are increasingly valuable. It remains unclear, however, whether country-level differences in cognitive function are attributable to population differences or bias due to incommensurate measurement. To demonstrate an effective method for cross-national comparison studies, we aimed to statistically harmonize measures of episodic memory and language function across two population-based cohorts of older adults in the United States (HRS HCAP) and India (LASI-DAD).

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Background: Home-based management of low-risk febrile neutropenia (FN) is safe, improves quality of life and reduces healthcare expenditure. A formal low-risk paediatric program has not been implemented in Australia. We aimed to describe the implementation process and evaluate the clinical impact.

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Intestinal stem cells (ISCs) are confined to crypt bottoms and their progeny differentiate near crypt-villus junctions. Wnt and bone morphogenic protein (BMP) gradients drive this polarity, and colorectal cancer fundamentally reflects disruption of this homeostatic signaling. However, sub-epithelial sources of crucial agonists and antagonists that organize this BMP gradient remain obscure.

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Little is known about how metabolites couple tissue-specific stem cell function with physiology. Here we show that, in the mammalian small intestine, the expression of Hmgcs2 (3-hydroxy-3-methylglutaryl-CoA synthetase 2), the gene encoding the rate-limiting enzyme in the production of ketone bodies, including beta-hydroxybutyrate (βOHB), distinguishes self-renewing Lgr5 stem cells (ISCs) from differentiated cell types. Hmgcs2 loss depletes βOHB levels in Lgr5 ISCs and skews their differentiation toward secretory cell fates, which can be rescued by exogenous βOHB and class I histone deacetylase (HDAC) inhibitor treatment.

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Objective: Detection of cognitive impairment suggestive of risk for Alzheimer's disease (AD) progression is crucial to the prevention of incipient dementia. This study was performed to determine if performance on a novel object discrimination task improved identification of earlier deficits in older adults at risk for AD.

Method: In total, 135 participants from the 1Florida Alzheimer's Disease Research Center [cognitively normal (CN), Pre-mild cognitive impairment (PreMCI), amnestic mild cognitive impairment (aMCI), and dementia] completed a test of object discrimination and traditional memory measures in the context of a larger neuropsychological and clinical evaluation.

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Background & Aims: The human gut microbiota is becoming increasingly recognized as a key factor in homeostasis and disease. The lack of physiologically relevant in vitro models to investigate host-microbe interactions is considered a substantial bottleneck for microbiota research. Organoids represent an attractive model system because they are derived from primary tissues and embody key properties of the native gut lumen; however, access to the organoid lumen for experimental perturbation is challenging.

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The perirhinal cortex (PRC) supports associative memory and perception, and PRC dysfunction impairs animals' abilities to associate stimulus features across sensory modalities. PRC damage also leads to deficits in discriminating between stimuli that share features. Although PRC-dependent stimulus discrimination has been shown to be impaired with advanced age, data regarding the abilities of older adults and other animals to form PRC-dependent associations have been equivocal.

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A predominant view of perirhinal cortex (PRC) and postrhinal/parahippocampal cortex (POR/PHC) function contends that these structures are tuned to represent objects and spatial information, respectively. However, known anatomical connectivity, together with recent electrophysiological, neuroimaging, and lesion data, indicate that both brain areas participate in spatial and nonspatial processing. Instead of content-based organization, the PRC and PHC/POR may participate in two computationally distinct cortical-hippocampal networks: one network that is tuned to process coarse information quickly, forming gist-like representations of scenes/environments, and a second network tuned to process information about the specific sensory details that are necessary for discrimination across sensory modalities.

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Our understanding of development and function of natural killer (NK) cells has progressed significantly in recent years. However, exactly how uterine NK (uNK) cells develop and function is still unclear. To help investigators that are beginning to study tissue NK cells, we summarize in this review our current knowledge of the development and function of uNK cells, and what is yet to be elucidated.

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Objective: Non-concussed individuals may report a variety of concussion-like symptoms even in the absence of a diagnosed brain injury. Previous studies described concussion-like symptom reporting in adolescent athletes. This study provides complementary data on concussion-like symptoms in collegiate athletes.

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Emerging evidence suggests that aging is associated with a reduced ability to distinguish perceptually similar stimuli in one's environment. As the ability to accurately perceive and encode sensory information is foundational for explicit memory, understanding the neurobiological underpinnings of discrimination impairments that emerge with advancing age could help elucidate the mechanisms of mnemonic decline. To this end, there is a need for preclinical approaches that robustly and reliably model age-associated perceptual discrimination deficits.

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Hippocampal-dependent episodic memory and stimulus discrimination abilities are both compromised in the elderly. The reduced capacity to discriminate between similar stimuli likely contributes to multiple aspects of age-related cognitive impairment; however, the association of these behaviors within individuals has never been examined in an animal model. In the present study, young and aged F344×BN F1 hybrid rats were cross-characterized on the Morris water maze test of spatial memory and a dentate gyrus-dependent match-to-position test of spatial discrimination ability.

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Uterine NK cells are innate lymphoid cells (ILC) that populate the uterus and expand during pregnancy, regulating placental development and fetal growth in humans and mice. We have recently characterized the composition of uterine ILCs (uILCs), some of which require the transcription factor NFIL3, but the extent to which NFIL3-dependent cells support successful reproduction in mice is unknown. By mating Nfil3 (-/-) females with wild-type males, here we show the effects of NFIL3 deficiency in maternal cells on both the changes in uILCs during pregnancy and the downstream consequences on reproduction.

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