215 research outputs found

    Regional association of pCASL-MRI with FDG-PET and PiB-PET in people at risk for autosomal dominant Alzheimer's disease.

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    Autosomal dominant Alzheimer's disease (ADAD) is a small subset of Alzheimer's disease that is genetically determined with 100% penetrance. It provides a valuable window into studying the course of pathologic processes that leads to dementia. Arterial spin labeling (ASL) MRI is a potential AD imaging marker that non-invasively measures cerebral perfusion. In this study, we investigated the relationship of cerebral blood flow measured by pseudo-continuous ASL (pCASL) MRI with measures of cerebral metabolism (FDG PET) and amyloid deposition (Pittsburgh Compound B (PiB) PET). Thirty-one participants at risk for ADAD (age 39 ± 13 years, 19 females) were recruited into this study, and 21 of them received both MRI and FDG and PiB PET scans. Considerable variability was observed in regional correlations between ASL-CBF and FDG across subjects. Both regional hypo-perfusion and hypo-metabolism were associated with amyloid deposition. Cross-sectional analyses of each biomarker as a function of the estimated years to expected dementia diagnosis indicated an inverse relationship of both perfusion and glucose metabolism with amyloid deposition during AD development. These findings indicate that neurovascular dysfunction is associated with amyloid pathology, and also indicate that ASL CBF may serve as a sensitive early biomarker for AD. The direct comparison among the three biomarkers provides complementary information for understanding the pathophysiological process of AD

    The effects of connectedness on health-promoting and health-compromising behaviors in adolescents: evidence from a statewide survey

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    Using a social ecological perspective, we examined the effects of connectedness in multiple domains on health-promoting and health-compromising behaviors among Asian American (AA), Pacific Islander (PI), and Caucasian/White American (WA) adolescents in California. After adjusting for age, gender, and socioeconomic status, the following consistent results emerged across the three ethnic groups: (a) community connectedness increased the odds of physical activity; (b) internal, family, and school connectedness decreased, whereas friend connectedness increased, the odds of substance use; and (c) internal and family connectedness decreased the odds of violent behavior. We also found specific ethnic variations pertaining to the effects of connectedness. Friend connectedness increased the odds of violent behavior for AAs and WAs, but not for PIs. Meanwhile, community connectedness increased the odds of substance use and violent behavior for AAs and PIs, but decreased the odds of these behaviors for WAs. Findings for healthy dietary behavior were inconsistent across ethnic groups and connectedness domains. Our overall findings suggest that the effects of connectedness were more salient for health-compromising behaviors than for health-promoting behaviors. Health prevention and intervention efforts in adolescents could target the role of their connectedness to their multiple social domains

    STEM Initiatives: Stimulating Students to Improve Science and Mathematics Achievement

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    The article focuses on how concepts in science, technology education, and mathematics show powerful relationships when it comes to student learning. Learning theorists believe that, through designed learning environments (contexts) and learning with hands-on projects, new knowledge can not only be learned, but learned in such a way that the knowledge can be transferred for other applications. Scholars in the applied sciences (school science, technology, and mathematics) believe that these subjects have transfer among themselves and that engineering activities can establish the contexts to learn these subjects, plus aid in the transfer of knowledge. This collaborative movement is referred to as STEM — integrating instruction in science, technology education, engineering, and mathematics. For more information on the national standards, conduct a web search for National Science Education Standards (1996), Standards for Technological Literacy: Content for the Study of Technology (2000/2002), and Principles and Standards for School Mathematics, (2000)

    33356 A multinational chart review to examine gastrointestinal symptoms and their management in patients treated with apremilast for plaque psoriasis

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    Background: Diarrhea and nausea are the most common adverse events observed in phase 3 clinical trials and real-world studies of apremilast, an oral phosphodiesterase-4 inhibitor indicated for moderate-to-severe plaque psoriasis. Methods: A retrospective chart review was conducted between June and November 2020 in the United States (US) and France among patients with moderate psoriasis experiencing gastrointestinal (GI) symptoms within 3 months of initiating apremilast. Results: Dermatologists in US (200) and in France (52) abstracted patient charts (US: 494, France: 128). The following GI symptoms were reported: ‒diarrhea (US: 67% [331/494]; France: 76% [97/128]) with median time from onset to resolution/improvement of 26 days (US) and 21 days (France) ‒nausea (US: 52% [255/494]; France: 34% [44/128]) with median time from onset to resolution/improvement of 21 days (US) and 24 days (France). Management strategies for diarrhea included pharmacologic (loperamide/bismuth subsalicylate/racecadotril) with or without nonpharmacologic (dietary modifications, taking with food)/fiber (US: 30% [99/331], France: 41% [40/97]) and nonpharmacologic only (US: 32% [105/331], France: 27% [26/97]). Management strategies for nausea included pharmacologic (diphenhydramine/metoclopramide/metopimazine) with or without nonpharmacologic (dietary modifications, taking with food, avoidance of vigorous activity) (US: 5% [14/255], France: 30% [13/44]) and nonpharmacologic only (US: 58% [147/255], France: 36% [16/44]). Resolution/improvement of GI symptoms was observed in patients who used pharmacologic strategies and nonpharmacologic strategies. Conclusions: Recommendations to manage diarrhea and nausea after apremilast initiation with pharmacologic or non-pharmacologic strategies were effective and symptoms usually resolved within 3-4 weeks of onset

    Comparative efficacy of low-dose versus standard-dose azithromycin for patients with yaws: a randomised non-inferiority trial in Ghana and Papua New Guinea

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    Background: A dose of 30 mg/kg of azithromycin is recommended for treatment of yaws, a disease targeted for global eradication. Treatment with 20 mg/kg of azithromycin is recommended for the elimination of trachoma as a public health problem. In some settings, these diseases are co-endemic. We aimed to determine the efficacy of 20 mg/kg of azithromycin compared with 30 mg/kg azithromycin for the treatment of active and latent yaws. Methods: We did a non-inferiority, open-label, randomised controlled trial in children aged 6–15 years who were recruited from schools in Ghana and schools and the community in Papua New Guinea. Participants were enrolled based on the presence of a clinical lesion that was consistent with infectious primary or secondary yaws and a positive rapid diagnostic test for treponemal and non-treponemal antibodies. Participants were randomly assigned (1:1) to receive either standard-dose (30 mg/kg) or low-dose (20 mg/kg) azithromycin by a computer-generated random number sequence. Health-care workers assessing clinical outcomes in the field were not blinded to the patient's treatment, but investigators involved in statistical or laboratory analyses and the participants were blinded to treatment group. We followed up participants at 4 weeks and 6 months. The primary outcome was cure at 6 months, defined as lesion healing at 4 weeks in patients with active yaws and at least a four-fold decrease in rapid plasma reagin titre from baseline to 6 months in patients with active and latent yaws. Active yaws was defined as a skin lesion that was positive for Treponema pallidum ssp pertenue in PCR testing. We used a non-inferiority margin of 10%. This trial was registered with ClinicalTrials.gov, number NCT02344628. Findings: Between June 12, 2015, and July 2, 2016, 583 (65·1%) of 895 children screened were enrolled; 292 patients were assigned a low dose of azithromycin and 291 patients were assigned a standard dose of azithromycin. 191 participants had active yaws and 392 had presumed latent yaws. Complete follow-up to 6 months was available for 157 (82·2%) of 191 patients with active yaws. In cases of active yaws, cure was achieved in 61 (80·3%) of 76 patients in the low-dose group and in 68 (84·0%) of 81 patients in the standard-dose group (difference 3·7%; 95% CI −8·4 to 15·7%; this result did not meet the non-inferiority criterion). There were no serious adverse events reported in response to treatment in either group. The most commonly reported adverse event at 4 weeks was gastrointestinal upset, with eight (2·7%) participants in each group reporting this symptom. Interpretation: In this study, low-dose azithromycin did not meet the prespecified non-inferiority margin compared with standard-dose azithromycin in achieving clinical and serological cure in PCR-confirmed active yaws. Only a single participant (with presumed latent yaws) had definitive serological failure. This work suggests that 20 mg/kg of azithromycin is probably effective against yaws, but further data are needed

    The Histone H3K79 Methyltransferase Dot1L Is Essential for Mammalian Development and Heterochromatin Structure

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    Dot1 is an evolutionarily conserved histone methyltransferase specific for lysine 79 of histone H3 (H3K79). In Saccharomyces cerevisiae, Dot1-mediated H3K79 methylation is associated with telomere silencing, meiotic checkpoint control, and DNA damage response. The biological function of H3K79 methylation in mammals, however, remains poorly understood. Using gene targeting, we generated mice deficient for Dot1L, the murine Dot1 homologue. Dot1L-deficient embryos show multiple developmental abnormalities, including growth impairment, angiogenesis defects in the yolk sac, and cardiac dilation, and die between 9.5 and 10.5 days post coitum. To gain insights into the cellular function of Dot1L, we derived embryonic stem (ES) cells from Dot1L mutant blastocysts. Dot1L-deficient ES cells show global loss of H3K79 methylation as well as reduced levels of heterochromatic marks (H3K9 di-methylation and H4K20 tri-methylation) at centromeres and telomeres. These changes are accompanied by aneuploidy, telomere elongation, and proliferation defects. Taken together, these results indicate that Dot1L and H3K79 methylation play important roles in heterochromatin formation and in embryonic development

    Psip1/p52 regulates posterior Hoxa genes through activation of lncRNA Hottip

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    Long noncoding RNAs (lncRNAs) have been implicated in various biological functions including the regulation of gene expression, however, the functionality of lncRNAs is not clearly understood and conflicting conclusions have often been reached when comparing different methods to investigate them. Moreover, little is known about the upstream regulation of lncRNAs. Here we show that the short isoform (p52) of a transcriptional co-activator—PC4 and SF2 interacting protein (Psip1), which is known to be involved in linking transcription to RNA processing, specifically regulates the expression of the lncRNA Hottip–located at the 5’ end of the Hoxa locus. Using both knockdown and knockout approaches we show that Hottip expression is required for activation of the 5’ Hoxa genes (Hoxa13 and Hoxa10/11) and for retaining Mll1 at the 5’ end of Hoxa. Moreover, we demonstrate that artificially inducing Hottip expression is sufficient to activate the 5’ Hoxa genes and that Hottip RNA binds to the 5’ end of Hoxa. By engineering premature transcription termination, we show that it is the Hottip lncRNA molecule itself, not just Hottip transcription that is required to maintains active expression of posterior Hox genes. Our data show a direct role for a lncRNA molecule in regulating the expression of developmentally-regulated mRNA genes in cis

    Analysis of Imprinted Gene Expression in Normal Fertilized and Uniparental Preimplantation Porcine Embryos

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    In the present study quantitative real-time PCR was used to determine the expression status of eight imprinted genes (GRB10, H19, IGF2R, XIST, IGF2, NNAT, PEG1 and PEG10) during preimplantation development, in normal fertilized and uniparental porcine embryos. The results demonstrated that, in all observed embryo samples, a non imprinted gene expression pattern up to the 16-cell stage of development was common for most genes. This was true for all classes of embryo, regardless of parental-origins and the direction of imprint. However, several differentially expressed genes (H19, IGF2, XIST and PEG10) were detected amongst the classes at the blastocyst stage of development. Most interestingly and despite the fact that maternally and paternally expressed genes should not be expressed in androgenones and parthenogenones, respectively, both uniparental embryos expressed these genes when tested for in this study. In order to account for this phenomenon, we compared the expression patterns of eight imprinted genes along with the methylation status of the IGF2/H19 DMR3 in haploid and diploid parthenogenetic embryos. Our findings revealed that IGF2, NNAT and PEG10 were silenced in haploid but not diploid parthenogenetic blastocysts and differential methylation of the IGF2/H19 DMR3 was consistently observed between haploid and diploid parthenogenetic blastocysts. These results appear to suggest that there exists a process to adjust the expression status of imprinted genes in diploid parthenogenetic embryos and that this phenomenon may be associated with altered methylation at an imprinting control region. In addition we believe that imprinted expression occurs in at least four genes, namely H19, IGF2, XIST and PEG10 in porcine blastocyst stage embryos

    Fatal Disseminated Cryptococcus gattii Infection in New Mexico

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    We report a case of fatal disseminated infection with Cryptococcus gattii in a patient from New Mexico. The patient had no history of recent travel to known C. gattii-endemic areas. Multilocus sequence typing revealed that the isolate belonged to the major molecular type VGIII. Virulence studies in a mouse pulmonary model of infection demonstrated that the strain was less virulent than other C. gattii strains. This represents the first documented case of C. gattii likely acquired in New Mexico
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