136 research outputs found

    Overt is no better than covert when rehearsing visuo-spatial information in working memory

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    In the present study, we examined whether eye movements facilitate retention of visuo-spatial information in working memory. In two experiments, participants memorised the sequence of the spatial locations of six digits across a retention interval. In some conditions, participants were free to move their eyes during the retention interval, but in others they either were required to remain fixated or were instructed to move their eyes exclusively to a selection of the memorised locations. Memory performance was no better when participants were free to move their eyes during the memory interval than when they fixated a single location. Furthermore, the results demonstrated a primacy effect in the eye movement behaviour that corresponded with the memory performance. We conclude that overt eye movements do not provide a benefit over covert attention for rehearsing visuo-spatial information in working memory

    Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT

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    Contains fulltext : 86695.pdf (publisher's version ) (Open Access)Rationale Pharmacokinetics of melatonin in children might differ from that in adults. Objectives This study aims to establish a dose–response relationship for melatonin in advancing dim light melatonin onset (DLMO), sleep onset (SO), and reducing sleep onset latency (SOL) in children between 6 and 12 years with chronic sleep onset insomnia (CSOI). Methods The method used for this study is the randomized, placebo-controlled double-blind trial. Children with CSOI (n=72) received either melatonin 0.05, 0.1, and 0.15 mg/kg or placebo during 1 week. Sleep was assessed with log and actigraphy during this week and the week before. Outcomes were the shifts in DLMO, SO, and SOL. Results Treatment with melatonin significantly advanced SO and DLMO by approximately 1 h and decreased SOL by 35 min. Within the three melatonin groups, effect size was not different, but the circadian time of administration (TOA) correlated significantly with treatment effect on DLMO (rs=-0.33, p=0.022) and SO (rs=-0.38, p=0.004), whereas clock TOA was correlated with SO shift (r=-0.35, p=0.006) and not with DLMO shift. Conclusions No dose–response relationship of melatonin with SO, SOL, and DLMO is found within a dosage range of 0.05–0.15 mg/kg. The effect of exogenous melatonin on SO, SOL, and DLMO increases with an earlier circadian TOA. The soporific effects of melatonin enhance the SO shift. This study demonstrates that melatonin for treatment of CSOI in children is effective in a dosage of 0.05 mg/kg given at least 1 to 2 h before DLMO and before desired bedtime.13 p

    Morbidity and Risk of Subsequent Diagnosis of HIV: A Population Based Case Control Study Identifying Indicator Diseases for HIV Infection

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    BACKGROUND: Early identification of persons with undiagnosed HIV infection is an important health care issue. We examined associations between diseases diagnosed in hospitals and risk of subsequent HIV diagnosis. METHODS: In this population-based case control study, cases were persons with incident HIV infection diagnosed in Denmark between 1 January 1995 and 1 June 2008. Risk-set sampling was used to identify 19 age- and gender-matched population controls for each HIV case, using the HIV diagnosis date as the index date for both cases and controls. Prior hospital diagnoses obtained from Danish medical databases were first categorized into 22 major disease categories (excluding AIDS-defining diseases except tuberculosis) and then subdivided into 161 subcategories, allowing us to examine specific diseases as potential HIV indicators by conditional logistic regression. RESULTS: The study included 2,036 HIV cases and 35,718 controls. Persons with the following disease categories had a high risk of HIV diagnosis during the subsequent 5-year period: sexually transmitted infections and viral hepatitis (adjusted odds ratio [aOR] = 12.3, 95% CI: 9.60-15.7), hematological diseases (aOR = 4.28, 3.13-5.85), lower respiratory tract infections (aOR = 3.98, 3.14-5.04)), CNS infections (aOR = 3.44, 1.74-6.80), skin infections (aOR = 3.05, 2.47-3.75), other infections (aOR = 4.64, 3.89-5.54), and substance abuse (aOR = 2.60, 2.06-3.29). Several specific diseases were associated with aORs >20 including syphilis, hepatitis A, non "A" viral hepatitis, herpes zoster, candida infection, endocarditis, thrombocytopenia, and opioid abuse. CONCLUSIONS: Targeted testing for HIV in patients diagnosed with diseases associated with HIV may lead to earlier treatment and thereby reduced morbidity, mortality and HIV transmission

    A supramolecular helix that disregards chirality

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    The functions of complex crystalline systems derived from supramolecular biological and non-biological assemblies typically emerge from homochiral programmed primary structures via first principles involving secondary, tertiary and quaternary structures. In contrast, heterochiral and racemic compounds yield disordered crystals, amorphous solids or liquids. Here, we report the self-assembly of perylene bisimide derivatives in a supramolecular helix that in turn self-organizes in columnar hexagonal crystalline domains regardless of the enantiomeric purity of the perylene bisimide. We show that both homochiral and racemic perylene bisimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecular level, self-organize to form single-handed helical assemblies with identical single-crystal-like order. We propose that this high crystalline order is generated via a cogwheel mechanism that disregards the chirality of the self-assembling building blocks. We anticipate that this mechanism will facilitate access to previously inaccessible complex crystalline systems from racemic and homochiral building blocks

    Optic Nerve Head Quantification in Idiopathic Intracranial Hypertension by Spectral Domain OCT

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    Objective: To evaluate 3D spectral domain optical coherence tomography (SDOCT) volume scans as a tool for quantification of optic nerve head (ONH) volume as a potential marker for treatment effectiveness and disease progression in idiopathic intracranial hypertension (IIH). Design and Patients: Cross-sectional pilot trial comparing 19 IIH patients and controls matched for gender, age and body mass index. Each participant underwent SDOCT. A custom segmentation algorithm was developed to quantify ONH volume (ONHV) and height (ONHH) in 3D volume scans. Results:Whereas peripapillary retinal nerve fiber layer thickness did not show differences between controls and IIH patients, the newly developed 3D parameters ONHV and ONHH were able to discriminate between controls, treated and untreated patients. Both ONHV and ONHH measures were related to levels of intracranial pressure (ICP). Conclusion: Our findings suggest 3D ONH measures as assessed by SDOCT as potential diagnostic and progression markers in IIH and other disorders with increased ICP. SDOCT may promise a fast and easy diagnostic alternative to repeated lumba

    High Uptake of Exclusive Breastfeeding and Reduced Early Post-Natal HIV Transmission

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    BACKGROUND. Empirical data showing the clear benefits of exclusive breastfeeding (EBF) for HIV prevention are needed to encourage implementation of lactation support programs for HIV-infected women in low resource settings among whom replacement feeding is unsafe. We conducted a prospective, observational study in Lusaka, Zambia, to test the hypothesis that EBF is associated with a lower risk of postnatal HIV transmission than non-EBF. METHODS AND RESULTS. As part of a randomized trial of early weaning, 958 HIV-infected women and their infants were recruited and all were encouraged to breastfeed exclusively to 4 months. Single-dose nevirapine was provided to prevent transmission. Regular samples were collected from infants to 24 months of age and tested by PCR. Detailed measurements of actual feeding behaviors were collected to examine, in an observational analysis, associations between feeding practices and postnatal HIV transmission. Uptake of EBF was high with 84% of women reporting only EBF cumulatively to 4 months. Post-natal HIV transmission before 4 months was significantly lower (p = 0.004) among EBF (0.040 95% CI: 0.024–0.055) than non-EBF infants (0.102 95% CI: 0.047–0.157); time-dependent Relative Hazard (RH) of transmission due to non-EBF = 3.48 (95% CI: 1.71–7.08). There were no significant differences in the severity of disease between EBF and non-EBF mothers and the association remained significant (RH = 2.68 95% CI: 1.28–5.62) after adjusting for maternal CD4 count, plasma viral load, syphilis screening results and low birth weight. CONCLUSIONS. Non-EBF more than doubles the risk of early postnatal HIV transmission. Programs to support EBF should be expanded universally in low resource settings. EBF is an affordable, feasible, acceptable, safe and sustainable practice that also reduces HIV transmission providing HIV-infected women with a means to protect their children's lives. TRIAL REGISTRATION. ClinicalTrials.gov NCT00310726National Institute of Child Health and Human Development; National Institutes of Health (R01 HD 39611, R01 HD 40777); Centers for Disease Control and Prevention; Global AIDS Program; Glaser Pediatric AIDS Foundation; USAID Country Research (GHS-A-00-00020-00

    Early transcriptional response in the jejunum of germ-free piglets after oral infection with virulent rotavirus

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    Germ-free piglets were orally infected with virulent rotavirus to collect jejunal mucosal scrapings at 12 and 18 hours post infection (two piglets per time point). IFN-gamma mRNA expression was stimulated in the mucosa of all four infected piglets, indicating that they all responded to the rotavirus infection. RNA pools prepared from two infected piglets were used to compare whole mucosal gene expression at 12 and 18 hpi to expression in uninfected germ-free piglets (n = 3) using a porcine intestinal cDNA microarray. Microarray analysis identified 13 down-regulated and 17 up-regulated genes. Northern blot analysis of a selected group of genes confirmed the data of the microarray. Genes were functionally clustered in interferon-regulated genes, proliferation/differentiation genes, apoptosis genes, cytoskeleton genes, signal transduction genes, and enterocyte digestive, absorptive, and transport genes. Down-regulation of the transport gene cluster reflected in part the loss of rotavirus-infected enterocytes from the villous tips. Data mining suggested that several genes were regulated in lower- or mid-villus immature enterocytes and goblet cells, probably to support repair of the damaged epithelial cell layer at the villous tips. Furthermore, up-regulation was observed for IFN-γ induced guanylate binding protein 2, a protein that effectively inhibited VSV and EMCV replication in vitro (Arch Virol 150:1213–1220, 2005). This protein may play a role in the small intestine’s innate defense against enteric viruses like rotavirus

    Prevalence of Symptomatic Heart Failure with Reduced and with Normal Ejection Fraction in an Elderly General Population-The CARLA Study

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    Background/Objectives: Chronic heart failure (CHF) is one of the most important public health concerns in the industrialized world having increasing incidence and prevalence. Although there are several studies describing the prevalence of heart failure with reduced ejection fraction (HFREF) and heart failure with normal ejection fraction (HFNEF) in selected populations, there are few data regarding the prevalence and the determinants of symptomatic heart failure in the general population. Methods: Cross-sectional data of a population-based German sample (1,779 subjects aged 45-83 years) were analyzed to determine the prevalence and determinants of chronic SHF and HFNEF defined according to the European Society of Cardiology using symptoms, echocardiography and serum NT-proBNP. Prevalence was age-standardized to the German population as of December 31st, 2005. Results: The overall age-standardized prevalence of symptomatic CHF was 7.7% (95%CI 6.0-9.8) for men and 9.0% (95%CI 7.0-11.5) for women. The prevalence of CHF strongly increased with age from 3.0% among 45-54- year-old subjects to 22.0% among 75-83- year-old subjects. Symptomatic HFREF could be shown in 48% (n = 78), symptomatic HFNEF in 52% (n = 85) of subjects with CHF. The age-standardized prevalence of HFREF was 3.8 % (95%CI 2.4-5.8) for women and 4.6 % (95%CI 3.6-6.3) for men. The age-standardized prevalence of HFNEF for women and men was 5.1 % (95%CI 3.8-7.0) and 3.0 % (95%CI 2.1-4.5), respectively. Persons with CHF were more likely to have hypertension (PR = 3.4; 95%CI 1.6-7.3) or to have had a previous myocardial infarction (PR = 2.5, 95%CI 1.8-3.5). Conclusion: The prevalence of symptomatic CHF appears high in this population compared with other studies. While more women were affected by HFNEF than men, more male subjects suffered from HFREF. The high prevalence of symptomatic CHF seems likely to be mainly due to the high prevalence of cardiovascular risk factors in this population

    A Review of Surgical Informed Consent: Past, Present, and Future. A Quest to Help Patients Make Better Decisions

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    Contains fulltext : 87422.pdf (publisher's version ) (Closed access)BACKGROUND: Informed consent (IC) is a process requiring a competent doctor, adequate transfer of information, and consent of the patient. It is not just a signature on a piece of paper. Current consent processes in surgery are probably outdated and may require major changes to adjust them to modern day legislation. A literature search may provide an opportunity for enhancing the quality of the surgical IC (SIC) process. METHODS: Relevant English literature obtained from PubMed, Picarta, PsycINFO, and Google between 1993 and 2009 was reviewed. RESULTS: The body of literature with respect to SIC is slim and of moderate quality. The SIC process is an underestimated part of surgery and neither surgeons nor patients sufficiently realize its importance. Surgeons are not specifically trained and lack the competence to guide patients through a legally correct SIC process. Computerized programs can support the SIC process significantly but are rarely used for this purpose. CONCLUSIONS: IC should be integrated into our surgical practice. Unfortunately, a big gap exists between the theoretical/legal best practice and the daily practice of IC. An optimally informed patient will have more realistic expectations regarding a surgical procedure and its associated risks. Well-informed patients will be more satisfied and file fewer legal claims. The use of interactive computer-based programs provides opportunities to improve the SIC process.1 juli 201
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