215 research outputs found

    Longitudinal evaluation of cognitive functioning in young children with type 1 diabetes over 18 months

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    OBJECTIVE: Decrements in cognitive function may already be evident in young children with type 1 diabetes (T1D). Here we report prospectively acquired cognitive results over 18 months in a large cohort of young children with and without T1D. METHODS: 144 children with T1D (mean HbA1c: 7.9%) and 70 age-matched healthy controls (mean age both groups 8.5 years; median diabetes duration 3.9 yrs; mean age of onset 4.1 yrs) underwent neuropsychological testing at baseline and after 18-months of follow-up. We hypothesized that group differences observed at baseline would be more pronounced after 18 months, particularly in those T1D patients with greatest exposure to glycemic extremes. RESULTS: Cognitive domain scores did not differ between groups at the 18 month testing session and did not change differently between groups over the follow-up period. However, within the T1D group, a history of diabetic ketoacidosis (DKA) was correlated with lower Verbal IQ and greater hyperglycemia exposure (HbA1c area under the curve) was inversely correlated to executive functions test performance. In addition, those with a history of both types of exposure performed most poorly on measures of executive function. CONCLUSIONS: The subtle cognitive differences between T1D children and nondiabetic controls observed at baseline were not observed 18 months later. Within the T1D group, as at baseline, relationships between cognition (VIQ and executive functions) and glycemic variables (chronic hyperglycemia and DKA history) were evident. Continued longitudinal study of this T1D cohort and their carefully matched healthy comparison group is planned

    Nonpharmacological interventions to improve depression, anxiety, and quality of life (QoL) in people with dementia: an overview of systematic reviews

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    This overview aimed to systematically synthesize evidence from existing systematic reviews to signpost practitioners to the current evidence base on nonpharmacological interventions to improve depression, anxiety, and quality of life (QoL) in people with dementia and to discuss priorities for future research. The databases MEDLINE, PsycINFO, Scopus, and Cochrane Central Register of Controlled Trials were searched in August 2017 with an updated search in January 2019. Fourteen systematic reviews of randomized controlled trials of nonpharmacological interventions were identified. Dementia stage was rated moderate or severe in the majority of the reviews and type of dementia varied. Interventions reported to be effective were cognitive stimulation (QoL: standardized mean difference [SMD] = 0.38), music-based therapeutic interventions (depression: SMD = −0.27, anxiety: SMD = −0.43, QoL: SMD = 0.32), and psychological treatments (mainly cognitive behavior therapy; depression: SMD = −0.22, anxiety: MD = −4.57). Although health-care professionals are recommended to continue using these approaches, future research needs to focus on the type and form of interventions that are most effective for different stages and types of dementia

    3D-printed SAXS chamber for controlled in situ dialysis and optical characterization

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    3D printing changes the scope of how samples can be mounted for small-angle X-ray scattering (SAXS). In this paper a 3D-printed X-ray chamber, which allows for in situ exchange of buffer and in situ optical transmission spectroscopy, is presented. The chamber is made of cyclic olefin copolymers (COC), including COC X-ray windows providing ultra-low SAXS background. The design integrates a membrane insert for in situ dialysis of the 100 ml sample volume against a reservoir, which enables measurements of the same sample under multiple conditions using an in-house X-ray setup equipped with a 17.4 keV molybdenum source. The design's capabilities are demonstrated by measuring reversible structural changes in lipid and polymer systems as a function of salt concentration and pH. In the same chambers optical light transmission spectroscopy was carried out measuring the optical turbidity of the mesophases and local pH values using pH-responsive dyes. Microfluidic exchange and optical spectroscopy combined with in situ X-ray scattering enables vast applications for the study of responsive materials

    Intramolecular Structural Heterogeneity altered by Long-range Contacts in an Intrinsically Disordered Protein

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    Short-range interactions and long-range contacts drive the 3D folding of structured proteins. The proteins' structure has a direct impact on their biological function. However, nearly 40% of the eukaryotes proteome is composed of intrinsically disordered proteins (IDPs) and protein regions that fluctuate between ensembles of numerous conformations. Therefore, to understand their biological function, it is critical to depict how the structural ensemble statistics correlate to the IDPs' amino acid sequence. Here, using small-angle x-ray scattering (SAXS) and time-resolved F\"orster resonance energy transfer (trFRET), we study the intra-molecular structural heterogeneity of the neurofilament low intrinsically disordered tail domain (NFLt). Using theoretical results of polymer physics, we find that the Flory scaling exponent of NFLt sub-segments correlates linearly with their net charge, ranging from statistics of ideal to self-avoiding chains. Surprisingly, measuring the same segments in the context of the whole NFLt protein, we find that regardless of the peptide sequence, the segments' structural statistics are more expanded than when measured independently. Our findings show that while polymer physics can, to some level, relate the IDP's sequence to its ensemble conformations, long-range contacts between distant amino acids play a crucial role in determining intra-molecular structures. This emphasizes the necessity of advanced polymer theories to fully describe IDPs ensembles with the hope it will allow us to model their biological function

    Cognitive functioning in young children with type 1 diabetes

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    OBJECTIVE: To assess cognitive functioning in children with type 1 diabetes (T1D) and examine whether glycemic history influences cognitive function. RESEARCH DESIGN AND METHODS: Neuropsychological evaluation of 216 children (healthy controls, n = 72; T1D, n = 144) ages 4-10yrs across five DirecNet sites. Cognitive domains included IQ, Executive Functions, Learning and Memory, and Processing Speed. Behavioral, mood, parental IQ data and T1D glycemic history since diagnosis were collected. RESULTS: The cohorts did not differ in age, gender or parent IQ. Median T1D duration was 2.5yrs and average onset age was 4yrs. After covarying age, gender, and parental IQ, the IQ and the Executive Functions domain scores trended lower (both p = .02, not statistically significant adjusting for multiple comparisons) with T1D relative to controls. Children with T1D were rated by parents as having more depressive and somatic symptoms (p < 0.001). Learning and memory (p = 0.46) and processing speed (p = 0.25) were similar. Trends in the data supported that the degree of hyperglycemia was associated with Executive Functions, and to a lesser extent, Child IQ and Learning and Memory. CONCLUSIONS: Differences in cognition are subtle in young children with T1D within 2 years of onset. Longitudinal evaluations will help determine whether these findings change or become more pronounced with time

    De novo mutations in SMCHD1 cause Bosma arhinia microphthalmia syndrome and abrogate nasal development

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    Bosma arhinia microphthalmia syndrome (BAMS) is an extremely rare and striking condition characterized by complete absence of the nose with or without ocular defects. We report here that missense mutations in the epigenetic regulator SMCHD1 mapping to the extended ATPase domain of the encoded protein cause BAMS in all 14 cases studied. All mutations were de novo where parental DNA was available. Biochemical tests and in vivo assays in Xenopus laevis embryos suggest that these mutations may behave as gain-of-function alleles. This finding is in contrast to the loss-of-function mutations in SMCHD1 that have been associated with facioscapulohumeral muscular dystrophy (FSHD) type 2. Our results establish SMCHD1 as a key player in nasal development and provide biochemical insight into its enzymatic function that may be exploited for development of therapeutics for FSHD
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