502 research outputs found

    Relationship between hippocampal structure and memory function in elderly humans

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    With progressing age, the ability to recollect personal events declines, whereas familiarity-based memory remains relatively intact. It has been hypothesized that age-related hippocampal atrophy may contribute to this pattern because of its critical role for recollection in younger humans and after acute injury. Here, we show that hippocampal volume loss in healthy older persons correlates with gray matter loss (estimated with voxel-based morphometry) of the entire limbic system and shows no correlation with an electrophysiological (event-related potential [ERP]) index of recollection. Instead, it covaries with more substantial and less specific electrophysiological changes of stimulus processing. Age-related changes in another complementary structural measure, hippocampal diffusion, on the other hand, seemed to be more regionally selective and showed the expected correlation with the ERP index of recollection. Thus, hippocampal atrophy in older persons accompanies limbic atrophy, and its functional impact on memory is more fundamental than merely affecting recollection

    A novel gamma-N-methylaminobutyrate demethylating oxidase involved in catabolism of the tobacco alkaloid nicotine by Arthrobacter nicotinovorans pAO1

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    Nicotine catabolism, linked in Arthrobacter nicotinovorans to the presence of the megaplasmid pAO1, leads to the formation of gamma-N-methylaminobutyrate from the pyrrolidine ring of the alkaloid. Until now the metabolic fate of gamma-N-methylaminobutyrate has been unknown. pAO1 carries a cluster of ORFs with similarity to sarcosine and dimethylglycine dehydrogenases and oxidases, to the bifunctional enzyme methylenetetrahydrofolate dehydrogenase/cyclohydrolase and to formyltetrahydrofolate deformylase. We cloned and expressed the gene carrying the sarcosine dehydrogenase-like ORF and showed, by enzyme activity, spectrophotometric methods and identification of the reaction product as gamma-aminobutyrate, that the predicted 89 395 Da flavoprotein is a demethylating gamma-N-methylaminobutyrate oxidase. Site-directed mutagenesis identified His67 as the site of covalent attachment of FAD and confirmed Trp66 as essential for FAD binding, for enzyme activity and for the spectral properties of the wild-type enzyme. A K-m of 140 mum and a k(cat) of 800 s(-1) was determined when gamma-N-methylaminobutyrate was used as the substrate. Sarcosine was also turned over by the enzyme, but at a rate 200-fold slower than gamma-N-methylaminobutyrate. This novel enzyme activity revealed that the first step in channelling the gamma-N-methylaminobutyrate generated from nicotine into the cell metabolism proceeds by its oxidative demethylation

    The structure of porin from Rhodobacter capsulatus at 1.8 Å resolution

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    AbstractThe structure of the porin from Rhodobacter capsulanus was determined at a resolution of 1.8 Å. The analysis started from a closely related crystal structure that had been solved at a medium resolution of 3 Å using multiple isomorphous replacement and solvent flattening. The new structure contains the complete sequence of 301 amino acid residues. Refinement of the model is under way: the present R-factor is 22% with good geometry. Except for the lengths of several loops, the resulting chain fold corresponds to the medium resolution model. The membrane channel is lined by a large number of ionogenic side chains with characteristic segregation of differently charged groups

    Examining the Links Between Challenging Behaviors in Youth with ASD and Parental Stress, Mental Health, and Involvement: Applying an Adaptation of the Family Stress Model to Families of Youth with ASD

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    Raising a child with autism spectrum disorder (ASD) poses unique challenges that may impact parents’ mental health and parenting experiences. The current study analyzed self-report data from 77 parents of youth with ASD. A serial multiple mediation model revealed that parenting stress (SIPA) and parental mental health (BAI and BDI-II) appears to be impacted by challenging adolescent behaviors (SSIS-PBs) and, in turn, affect parental involvement (PRQ), controlling for social skills (SSIS-SSs). Further, the study explored the malleability of parents’ mental health over the course of a social skills intervention, and provides modest evidence that parent depressive symptoms decline across intervention. This study illustrates the importance of considering the entire family system in research on youth with ASD

    Social Difficulties in Youth with Autism With and Without Anxiety and ADHD Symptoms

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    Social difficulties inherent to autism spectrum disorder are often linked with co‐occurring symptoms of anxiety and attention deficit hyperactivity disorder (ADHD). The present study sought to examine the relation between such co‐occurring symptoms and social challenges. Parents of adolescents with autism (N = 113) reported upon social challenges via the social responsiveness scale (SRS) and anxiety and ADHD symptomatology via the Child Behavior Checklist. Results revealed differences in SRS scores across co‐occurring symptom subgroups (Anxiety, ADHD, Both, Neither)—namely, adolescents with autism and anxiety as well as those with autism, anxiety, and ADHD showed greater scores on the SRS than the other groups. Implications for research and clinical practice are discussed and recommendations are offered. Lay Summary Anxiety and attention deficit hyperactivity disorder (ADHD) symptoms are related to greater social challenges for adolescents with autism spectrum disorder. The present study found that autism with anxiety and autism with anxiety and ADHD, was related to greater social difficulties than autism alone. Findings provide further support for the intertwined nature of anxiety and ADHD symptoms in autism. What this may mean for research and clinical practice is considered and recommendations are suggested

    Social Difficulties in Youth with Autism With and Without Anxiety and ADHD Symptoms

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    Social difficulties inherent to autism spectrum disorder are often linked with co‐occurring symptoms of anxiety and attention deficit hyperactivity disorder (ADHD). The present study sought to examine the relation between such co‐occurring symptoms and social challenges. Parents of adolescents with autism (N = 113) reported upon social challenges via the social responsiveness scale (SRS) and anxiety and ADHD symptomatology via the Child Behavior Checklist. Results revealed differences in SRS scores across co‐occurring symptom subgroups (Anxiety, ADHD, Both, Neither)—namely, adolescents with autism and anxiety as well as those with autism, anxiety, and ADHD showed greater scores on the SRS than the other groups. Implications for research and clinical practice are discussed and recommendations are offered. Lay Summary Anxiety and attention deficit hyperactivity disorder (ADHD) symptoms are related to greater social challenges for adolescents with autism spectrum disorder. The present study found that autism with anxiety and autism with anxiety and ADHD, was related to greater social difficulties than autism alone. Findings provide further support for the intertwined nature of anxiety and ADHD symptoms in autism. What this may mean for research and clinical practice is considered and recommendations are suggested

    Functional Status in Older Women Diagnosed with Pelvic Organ Prolapse

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    Background—Functional status plays an important role in the comprehensive characterization of older adults. Functional limitations are associated with an increased risk of adverse treatment outcomes, but there is limited data on the prevalence of functional limitations in older women with pelvic floor disorders. Objective—The aim of the study was to describe the prevalence of functional limitations based on health status in older women with pelvic organ prolapse. Study Design—This pooled, cross-sectional study utilized data from the linked Health and Retirement Study and Medicare files between 1992 and 2008. The analysis included 890 women ≥65 years with pelvic organ prolapse. We assessed self-reported functional status, categorized in strength, upper and lower body mobility, activities of daily living, and instrumental activities of daily living domains. Functional limitations were evaluated and stratified by respondents self-reported general health status. Descriptive statistics were used to compare categorical and continuous variables, and logistic regression was used to measure differences in the odds of functional limitation by increasing age. Results—The prevalence of functional limitations was 76.2% in strength, 44.9% in upper and 65.8% in lower body mobility, 4.5% in activities of daily living and 13.6% in instrumental activities of daily living. Limitations were more prevalent in women with poor or fair health status than in women with good health status, including 91.5% vs 69.9% in strength, 72.9% vs 33.5% in upper and 88.0% vs 56.8% in lower body mobility, 11.6% vs 0.9% in activities of daily living, and 30.6% vs 6.7% in instrumental activities of daily living, all p Conclusion—Functional limitations, especially in strength and body mobility domains, are highly prevalent in older women with pelvic organ prolapse, particularly in those with poor or fair self-reported health status. Future research is necessary to evaluate if functional status affects clinical outcomes in pelvic reconstructive and gynecologic surgery and whether it should be routinely assessed in clinical decision-making when treating older women with pelvic organ prolapse

    Functional Status in Older Women Diagnosed with Pelvic Organ Prolapse

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    Background—Functional status plays an important role in the comprehensive characterization of older adults. Functional limitations are associated with an increased risk of adverse treatment outcomes, but there is limited data on the prevalence of functional limitations in older women with pelvic floor disorders. Objective—The aim of the study was to describe the prevalence of functional limitations based on health status in older women with pelvic organ prolapse. Study Design—This pooled, cross-sectional study utilized data from the linked Health and Retirement Study and Medicare files between 1992 and 2008. The analysis included 890 women ≥65 years with pelvic organ prolapse. We assessed self-reported functional status, categorized in strength, upper and lower body mobility, activities of daily living, and instrumental activities of daily living domains. Functional limitations were evaluated and stratified by respondents self-reported general health status. Descriptive statistics were used to compare categorical and continuous variables, and logistic regression was used to measure differences in the odds of functional limitation by increasing age. Results—The prevalence of functional limitations was 76.2% in strength, 44.9% in upper and 65.8% in lower body mobility, 4.5% in activities of daily living and 13.6% in instrumental activities of daily living. Limitations were more prevalent in women with poor or fair health status than in women with good health status, including 91.5% vs 69.9% in strength, 72.9% vs 33.5% in upper and 88.0% vs 56.8% in lower body mobility, 11.6% vs 0.9% in activities of daily living, and 30.6% vs 6.7% in instrumental activities of daily living, all p Conclusion—Functional limitations, especially in strength and body mobility domains, are highly prevalent in older women with pelvic organ prolapse, particularly in those with poor or fair self-reported health status. Future research is necessary to evaluate if functional status affects clinical outcomes in pelvic reconstructive and gynecologic surgery and whether it should be routinely assessed in clinical decision-making when treating older women with pelvic organ prolapse

    Measurement Matters: A commentary on the state of the science on patient reported outcome measures (PROMs) in autism research

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    High quality science relies upon psychometrically valid and reliable measurement, yet very few Patient Reported Outcome Measures (PROMs) have been developed or thoroughly validated for use with autistic individuals. The present commentary summarizes the current state of autism PROM science, based on discussion at the Special Interest Group (SIG) at the 2022 International Society for Autism Research (INSAR) Annual Meeting and collective expertise of the authors. First, we identify current issues in autism PROM research including content and construct operationalization, informant-structure, measure accessibility, and measure validation and generalization. We then enumerate barriers to conducting and disseminating this research, such as a lack of guidance, concerns regarding funding and time, lack of accessible training and professionals with psychometric skills, difficulties collecting large representative samples, and challenges with dissemination. Lastly, we offer future priorities and resources to improve PROMs in autism research including a need to continue to evaluate and develop PROMs for autistic people using robust methods, to prioritize diverse and representative samples, to expand the breadth of psychometric properties and techniques, and to consider developing field specific guidelines. We remain extremely optimistic about the future directions of this area of autism research. This work is well positioned to have an immense, positive impact on our scientific understanding of autism and the everyday lives of autistic people and their families
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