RESUMEN
Studies of the impact of brain injury on memory processes often focus on the quantity and episodic richness of those recollections. Here, we argue that the organization of one's recollections offers critical insights into the impact of brain injury on functional memory. It is well-established in studies of word list memory that free recall of unrelated words exhibits a clear temporal organization. This temporal contiguity effect refers to the fact that the order in which word lists are recalled reflects the original presentation order. Little is known, however, about the organization of recall for semantically rich materials, nor how recall organization is impacted by hippocampal damage and memory impairment. The present research is the first study, to our knowledge, of temporal organization in semantically rich narratives in three groups: (1) Adults with bilateral hippocampal damage and severe declarative memory impairment, (2) adults with bilateral ventromedial prefrontal cortex (vmPFC) damage and no memory impairment, and (3) demographically matched non-brain-injured comparison participants. We find that although the narrative recall of adults with bilateral hippocampal damage reflected the temporal order in which those narratives were experienced above chance levels, their temporal contiguity effect was significantly attenuated relative to comparison groups. In contrast, individuals with vmPFC damage did not differ from non-brain-injured comparison participants in temporal contiguity. This pattern of group differences yields insights into the cognitive and neural systems that support the use of temporal organization in recall. These data provide evidence that the retrieval of temporal context in narrative recall is hippocampal-dependent, whereas damage to the vmPFC does not impair the temporal organization of narrative recall. This evidence of limited but demonstrable organization of memory in participants with hippocampal damage and amnesia speaks to the power of narrative structures in supporting meaningfully organized recall despite memory impairment.
Asunto(s)
Amnesia , Hipocampo , Recuerdo Mental , Humanos , Hipocampo/patología , Hipocampo/diagnóstico por imagen , Hipocampo/fisiopatología , Recuerdo Mental/fisiología , Masculino , Femenino , Persona de Mediana Edad , Amnesia/fisiopatología , Amnesia/patología , Amnesia/psicología , Adulto , Narración , Anciano , Pruebas Neuropsicológicas , Factores de Tiempo , Corteza Prefrontal/patología , Corteza Prefrontal/fisiopatología , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/lesionesRESUMEN
Over 30,000 point mutations are associated with debilitating diseases, including many cancer types, underscoring a critical need for targeted genomic solutions. CRISPR base editors, like adenine base editors (ABEs) and cytosine base editors (CBEs), enable precise modifications by converting adenine to guanine and cytosine to thymine, respectively. Challenges in efficiency and safety concerns regarding viral vectors used in delivery limit the scope of base editing. This study introduces non-viral minicircles, bacterial-backbone-free plasmids, as a delivery vehicle for ABEs and CBEs. The research uses cells engineered with the "Gene On" (GO) reporter gene systems for tracking minicircle-delivered ABEs, CBEs, or Cas9 nickase (control), using green fluorescent protein (GFPGO), bioluminescence reporter firefly luciferase (LUCGO), or a highly sensitive Akaluciferase (AkalucGO) designed in this study. The results show that transfection of minicircles expressing CBE or ABE resulted in significantly higher GFP expression and luminescence signals over controls, with minicircles demonstrating the most substantial editing. This study presents minicircles as a new strategy for base editor delivery and develops an enhanced bioluminescence imaging reporter system for tracking ABE activity. Future studies aim to evaluate the use of minicircles in preclinical cancer models, facilitating potential clinical applications.
RESUMEN
BACKGROUND: Breastfeeding provides physical, psychological, and immunological benefits to both the mother and infant, but breastfeeding rates are suboptimal. The purpose of this study was to examine whether residing in a maternity care desert (a county with no hospital offering obstetric care and no OB/GYN or certified nurse midwife providers) was associated with lower breastfeeding rates among birthing people in Louisiana from 2019 to 2020. METHODS: Data provided by the March of Dimes were used to classify Louisiana parishes by level of access to maternity care. Using data on all live births provided by the Louisiana Office of Vital Records (n = 112,151), we fit adjusted modified Poisson regression models with generalized estimating equations and exploratory geospatial analysis to examine the association between place of residence and breastfeeding initiation and racial disparities in initiation. We conducted a secondary within-group analysis by fitting the fully adjusted model stratified by race/ethnicity for non-Hispanic white and non-Hispanic Black birthing people. RESULTS: We found that residing in a parish with limited (odds ratio [OR] = 0.87; 95% confidence interval [CI] [0.77, 0.99]) to no access (OR = 0.88; 95% CI [0.80, 0.97]) was significantly associated with lower breastfeeding initiation rates. The within-group analysis determined that both non-Hispanic Black and non-Hispanic white birthing people residing in a parish with limited or no maternity care access had lower breastfeeding initiation rates. CONCLUSION: Reducing rural and racial inequities in breastfeeding may require structural changes and investments in infrastructure to deliver pregnancy care.