151 research outputs found

    Bending modes of DNA directly addressed by cryo-electron microscopy of DNA minicircles

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    We use cryo-electron microscopy (cryo-EM) to study the 3D shapes of 94-bp-long DNA minicircles and address the question of whether cyclization of such short DNA molecules necessitates the formation of sharp, localized kinks in DNA or whether the necessary bending can be redistributed and accomplished within the limits of the elastic, standard model of DNA flexibility. By comparing the shapes of covalently closed, nicked and gapped DNA minicircles, we conclude that 94-bp-long covalently closed and nicked DNA minicircles do not show sharp kinks while gapped DNA molecules, containing very flexible single-stranded regions, do show sharp kinks. We corroborate the results of cryo-EM studies by using Bal31 nuclease to probe for the existence of kinks in 94-bp-long minicircle

    Identification and characterization of ERV-W-like sequences in Platyrrhini species provides new insights into the evolutionary history of ERV-W in primates

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    Background: Endogenous Retroviruses (ERVs) constitute approximately 8% of every human genome and are relics of ancestral infections that affected the germ line cells. The ERV-W group contributed to primate physiology by providing an envelope protein (Syncytin-1) that has been adopted for placenta development in hominoids. Expression of Human ERV-W (HERV-W) sequences is investigated for a pathological role in various human diseases. Results: We previously characterized ERV-W group genomic sequences in human and non-human Catarrhini species. We now investigated ERV-W-like sequences in the parvorder Platyrrhini, especially regarding two species with complete genome assemblies, namely marmoset (Callithrix jacchus) and squirrel monkey (Saimiri boliviensis). We identified in both species proviral sequences, annotated as ERV1-1 in respective genome assemblies, sharing high sequence similarities with Catarrhini ERV-W. A total of 130 relatively intact proviruses from the genomes of marmoset and squirrel monkey were characterized regarding their structural and evolutionarily relationships with Catarrhini ERV-W elements. Platyrrhini ERV-W sequences share several structural features with Catarrhini ERV-W elements and are closely related phylogenetically with the latter as well as with other ERV-W-related gammaretrovirus-like ERVs. The ERV-W group colonized Platyrrhini primates of both Callitrichidae and Atelidae lineages, with provirus formations having occurred mostly between 25 and 15 mya. Two LTR subgroups were associated with monophyletic proviral bodies. A pre-gag region appears to be a sequence feature common to the ERV-W group: it harbors a putative intron sequence that is missing in some ERV-W loci, holding a putative ORF as well. The presence of a long pre-gag portion was confirmed among all gammaretroviral ERV analyzed, suggesting a role in the latter biology. It is noteworthy that, contrary to Catarrhini ERV-W, there was no evidence of L1-mediated mobilization for Platyrrhini ERV-W sequences. Conclusions: Our data establish that ERV-W is not exclusive to Catarrhini primates but colonized both parvorders of Simiiformes, providing further insight into the evolution of ERV-W and the colonization of primate genomes

    Pet ownership and cognitive decline in older people

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    Animals can have a positive influence on human health. However, it is not yet known whether pet ownership can prevent cognitive decline. Therefore, we aimed to investigate cross-sectional and prospective associations between pet ownership and cognitive function in a large, representative sample of older adults. Data were from the English Longitudinal Study of Ageing (ELSA) using data collected in wave 5 and six years later in wave 8. Pet ownership was categorized as no pet, dog, cat or other pet. Cognitive function was assessed using tests of verbal fluency (assessed by asking how many different animals the participants could name in 60 seconds) and memory (sum of immediate and delayed verbal recall). Multiple linear regression, adjusted for potential confounders, was used to test the associations between pet ownership and cognitive function. A total of 8291 people (mean age: 66.72 years) were included. In cross-sectional analyses, dog owners had better verbal fluency than individuals with no pet, but there was no significant difference between cat or other pet owners and those with no pet. In prospective analyses, dog owners had a significantly larger decline in recall than those with no pet, whilst cat owners had a significantly smaller decline in verbal fluency. These results provide some evidence to suggest that pet ownership may have positive effects on cognition in later life. However, benefits of pet ownership were not unilaterally observed across different types of pet and measures of cognitive function suggesting that further research is required

    Patient safety culture in Italian out-ofhours primary care service: a national cross-sectional survey study

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    Background: Out-of-hours (OOH) services in Italy provide >10 million consultations every year. To the authors' knowledge, no data on patient safety culture (PSC) have been reported. Aim: To assess PSC in the Italian OOH setting. Design & setting: National cross-sectional survey using the Safety Attitudes Questionnaire — Ambulatory Version (SAQ-AV). Method: The SAQ-AV was translated into Italian and distributed in a convenience sample of OOH doctors in 2015. Answers were collected anonymously by Qualtrics. Stata (version 14) was used to estimate Cronbach's alpha, perform exploratory and confirmatory factor analysis, correlate items to doctors' characteristics, and to do item descriptive analysis. Results: Overall, 692 OOH doctors were contacted, with a 71% response rate. In the exploratory factor analysis (EFA), four factors were identified: Communication and Safety Climate (14 items); Perceptions of Management (eight items); Workload and Clinical Risk (six items); and Burnout Risk (four items). These four factors accounted for 68% of the total variance (Kaiser-Meyer-Olkin [KMO] statistic = 0.843). Cronbach's alpha ranged from 0.710-0.917. OOH doctors were often dissatisfied with their job; there is insufficient staff to provide optimal care and there is no training or supervision for new personnel and family medicine trainees. Service managers are perceived as distant, with particular issues concerning the communication between managers and OOH doctors. A large proportion of OOH doctors (56.8%) state that they do not receive adequate support. Conclusion: These findings could be useful for informing policies on how to improve PSC in Italian OOH service

    Ethnic Differences in Magnesium Intake in U.S. Older Adults: Findings from NHANES 2005–2016

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    Magnesium plays a crucial role in hundreds of bodily processes relevant to aging, but consumption of dietary magnesium intake has been shown to be inadequate in a large proportion of older adults. Identifying groups at risk of low magnesium intake is important for informing targeted advice. Using data from the National Health and Nutrition Examination Survey (NHANES) 2005–2016, we examined the association between ethnicity (Caucasian/African American/Hispanic/other) and magnesium intake in a large representative sample of U.S. older adults (≥65 y, n = 5682, mean (SD) 72.9 (0.10) y). Analyses adjusted for total energy intake and a range of relevant covariates. Overall, 83.3% of participants were not meeting the recommended level of dietary magnesium intake, ranging from 78.1% of other ethnic groups to 90.6% of African Americans. In the fully adjusted model, magnesium intake was lower among African American older adults (−13.0 mg/d, 95% CI: −18.8 to −7.2), and higher among Hispanics (14.0 mg/d, 95% CI: 7.5 to 20.5) and those from other ethnic groups (17.2, 95% CI: 3.8 to 30.5) compared with Caucasian older adults. These results highlight the need for targeted interventions to increase magnesium intake in U.S. older adults, with a focus on African Americans, in order to reduce the burden of morbidity and ethnic inequalities in health in later life

    Essential steps in primary care management of older people with Type 2 diabetes: an executive summary on behalf of the European geriatric medicine society (EuGMS) and the European diabetes working party for older people (EDWPOP) collaboration

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    We present an executive summary of a guideline for management of type 2 diabetes mellitus in primary care written by the European Geriatric Medicine Society, the European Diabetes Working Party for Older People with contributions from primary care practitioners and participation of a patient’s advocate. This consensus document relies where possible on evidence-based recommendations and expert opinions in the fields where evidences are lacking. The full text includes 4 parts: a general strategy based on comprehensive assessment to enhance quality and individualised care plan, treatments decision guidance, management of complications, and care in case of special conditions. Screening for frailty and cognitive impairment is recommended as well as a comprehensive assessment all health conditions are concerned, including end of life situations. The full text is available online at the following address: essential_steps_inprimary_care_in_older_people_with_diabetes_-_EuGMS-EDWPOP___3_.pdf

    A genome-wide association study of sodium levels and drug metabolism in an epilepsy cohort treated with carbamazepine and oxcarbazepine

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    Epilepsia Open published by Wiley Periodicals Inc. on behalf of International League Against Epilepsy. Objective: To ascertain the clinical and genetic factors contributing to carbamazepine- and oxcarbazepine-induced hyponatremia (COIH), and to carbamazepine (CBZ) metabolism, in a retrospectively collected, cross-sectional cohort of people with epilepsy. Methods: We collected data on serum sodium levels and antiepileptic drug levels in people with epilepsy attending a tertiary epilepsy center while on treatment with CBZ or OXC. We defined hyponatremia as Na+ ≤134 mEq/L. We estimated the CBZ metabolic ratio defined as the log transformation of the ratio of metabolite CBZ-diol to unchanged drug precursor substrate as measured in serum. Results: Clinical and genetic data relating to carbamazepine and oxcarbazepine trials were collected in 1141 patients. We did not observe any genome-wide significant associations with sodium level in a linear trend or hyponatremia as a dichotomous trait. Age, sex, number of comedications, phenytoin use, phenobarbital use, and sodium valproate use were significant predictors of CBZ metabolic ratio. No genome-wide significant associations with CBZ metabolic ratio were found. Significance: Although we did not detect a genetic predictor of hyponatremia or CBZ metabolism in our cohort, our findings suggest that the determinants of CBZ metabolism are multifactorial

    Bending modes of DNA directly addressed by cryo-electron microscopy of DNA minicircles

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    We use cryo-electron microscopy (cryo-EM) to study the 3D shapes of 94-bp-long DNA minicircles and address the question of whether cyclization of such short DNA molecules necessitates the formation of sharp, localized kinks in DNA or whether the necessary bending can be redistributed and accomplished within the limits of the elastic, standard model of DNA flexibility. By comparing the shapes of covalently closed, nicked and gapped DNA minicircles, we conclude that 94-bp-long covalently closed and nicked DNA minicircles do not show sharp kinks while gapped DNA molecules, containing very flexible single-stranded regions, do show sharp kinks. We corroborate the results of cryo-EM studies by using Bal31 nuclease to probe for the existence of kinks in 94-bp-long minicircles
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