395 research outputs found

    Direction specific error patterns during continuous tracking of the subjective visual vertical

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    The aim of this study was to characterize the error pattern of continuously tracking the perceived earth-vertical during roll rotations from upright to right or left ear-down and from right or left ear-down to upright. We compared the tracking responses of two paradigms, which either continuously activated the otoliths organs alone (constant velocity tilt) or both the otolith organs and the semicircular canals (constant acceleration tilt). The tracking responses of the subjective visual vertical showed characteristic differences depending on starting position and tilt direction relative to gravity. The error patterns in the constant-velocity and constant-acceleration tilt paradigm were reversed. Estimations during tracking, when otolith information was continuously changing, were more precise compared to estimations following fast tilts to fixed roll tilt positions. We conclude that the central processing underlying these perceptual tracking responses requires, besides the otolith input, information from the vertical semicircular canal

    Commentary: Challenging public health orthodoxies—prophesy or heresy?†

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    In 1633, after many years of skirmishing with the Catholic Church over his support for Copernicus’ heliocentric theory of the universe, Galileo was finally sentenced by the inquisition to prison and religious penances. In a formal ceremony at the church of Santa Maria Sofia Minerva, he was forced to abjure his errors, and spent the rest of his life under house arrest in Sienna. The prophet had been convicted as a heretic. Without, yet, wishing to confer the status of prophet on Peter Aaby and his disciples based in Guinea Bissau, there are significant parallels in their persistent challenges to some of the deepest rooted public health orthodoxies of the present day. Aaby has a long history of interrogating datasets in a way that others hav

    Endomicroscopic and transcriptomic analysis of impaired barrier function and malabsorption in environmental enteropathy

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    Introduction: Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. Methods: We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. Results: CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (β = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (β = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (β = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. Conclusions: Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE

    Brain Apolipoprotein E: an Important Regulator of Food Intake in Rats

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    OBJECTIVE—The worldwide prevalence of obesity is increasing at an alarming rate, along with the associated increased rates of type 2 diabetes, heart disease, and some cancers. While efforts to address environmental factors responsible for the recent epidemic must continue, investigation into the anorectic functions of potential molecules we present here, such as apolipoprotein (apo)E, offers exciting possibilities for future development of successful anti-obesity therapies

    Severe malnutrition with and without HIV-1 infection in hospitalised children in Kampala, Uganda: differences in clinical features, haematological findings and CD4(+ )cell counts

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    BACKGROUND: The aim of this study was to describe the clinical features, haematological findings and CD4(+ )and CD8(+ )cell counts of severely malnourished children in relation to human immunodeficiency virus (HIV) infection. METHODS: The study was conducted in the paediatric wards of Mulago hospital, which is Uganda's national referral and teaching hospital. We studied 315 severely malnourished children (presence of oedema and/or weight-for-height: z-score < -3) and have presented our findings. At admission, the CD4(+ )and CD8(+ )cells were measured by the flow cytometry and HIV serology was confirmed by Enzyme linked Immunoassay for children >18 months of age, and RNA PCR was performed for those ≤18 months. Complete blood count, including differential counts, was determined using a Beckman Coulter counter. RESULTS: Among the 315 children, 119 (38%) were female; the median age of these children was 17 months (Interquartile range 12–24 months), and no difference was observed in the HIV status with regard to gender or age. The children showed a high prevalence of infections: pneumonia (68%), diarrhoea (38%), urinary tract infection (26%) and bacteraemia (18%), with no significant difference with regard to the HIV status (HIV-positive versus HIV-negative children). However, the HIV-positive children were more likely to have persistent diarrhoea than the HIV-uninfected severely malnourished children (odds ratio (OR) 2.0, 95% confidence interval (CI) 1.2–3.6). When compared with the HIV-negative children, the HIV-positive children showed a significantly lower median white blood cell count (10700 versus 8700) and lymphocyte count (4033 versus 2687). The CD4(+ )cell percentages were more likely to be lower in children with non-oedematous malnutrition than in those with oedematous malnutrition even after controlling for the HIV infection. The novel observation of this study is that the CD4(+ )percentages in both HIV-positive and HIV-negative children without oedema were lower that those in children with oedema. These observations appear to imply that the development of oedema requires a certain degree of immunocompetence, which is an interesting clue to the pathophysiology of oedema in severe malnutrition
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