281 research outputs found

    Individual Differences and Metacognitive Knowledge of Visual Search Strategy

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    A crucial ability for an organism is to orient toward important objects and to ignore temporarily irrelevant objects. Attention provides the perceptual selectivity necessary to filter an overwhelming input of sensory information to allow for efficient object detection. Although much research has examined visual search and the ‘template’ of attentional set that allows for target detection, the behavior of individual subjects often reveals the limits of experimental control of attention. Few studies have examined important aspects such as individual differences and metacognitive strategies. The present study analyzes the data from two visual search experiments for a conjunctively defined target (Proulx, 2007). The data revealed attentional capture blindness, individual differences in search strategies, and a significant rate of metacognitive errors for the assessment of the strategies employed. These results highlight a challenge for visual attention studies to account for individual differences in search behavior and distractibility, and participants that do not (or are unable to) follow instructions

    Glucosylsphingosine Is a Highly Sensitive and Specific Biomarker for Primary Diagnostic and Follow-Up Monitoring in Gaucher Disease in a Non-Jewish, Caucasian Cohort of Gaucher Disease Patients

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    Gaucher disease (GD) is the most common lysosomal storage disorder (LSD). Based on a deficient β-glucocerebrosidase it leads to an accumulation of glucosylceramide. Standard diagnostic procedures include measurement of enzyme activity, genetic testing as well as analysis of chitotriosidase and CCL18/PARC as biomarkers. Even though chitotriosidase is the most well-established biomarker in GD, it is not specific for GD. Furthermore, it may be false negative in a significant percentage of GD patients due to mutation. Additionally, chitotriosidase reflects the changes in the course of the disease belatedly. This further enhances the need for a reliable biomarker, especially for the monitoring of the disease and the impact of potential treatments.Here, we evaluated the sensitivity and specificity of the previously reported biomarker Glucosylsphingosine with regard to different control groups (healthy control vs. GD carriers vs. other LSDs).Only GD patients displayed elevated levels of Glucosylsphingosine higher than 12 ng/ml whereas the comparison controls groups revealed concentrations below the pathological cut-off, verifying the specificity of Glucosylsphingosine as a biomarker for GD. In addition, we evaluated the biomarker before and during enzyme replacement therapy (ERT) in 19 patients, demonstrating a decrease in Glucosylsphingosine over time with the most pronounced reduction within the first 6 months of ERT. Furthermore, our data reveals a correlation between the medical consequence of specific mutations and Glucosylsphingosine.In summary, Glucosylsphingosine is a very promising, reliable and specific biomarker for GD

    Anchoring of proteins to lactic acid bacteria

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    The anchoring of proteins to the cell surface of lactic acid bacteria (LAB) using genetic techniques is an exciting and emerging research area that holds great promise for a wide variety of biotechnological applications. This paper reviews five different types of anchoring domains that have been explored for their efficiency in attaching hybrid proteins to the cell membrane or cell wall of LAB. The most exploited anchoring regions are those with the LPXTG box that bind the proteins in a covalent way to the cell wall. In recent years, two new modes of cell wall protein anchoring have been studied and these may provide new approaches in surface display. The important progress that is being made with cell surface display of chimaeric proteins in the areas of vaccine development and enzyme- or whole-cell immobilisation is highlighted.

    Critical Early Roles for col27a1a and col27a1b in Zebrafish Notochord Morphogenesis, Vertebral Mineralization and Post-embryonic Axial Growth

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    Fibrillar collagens are well known for their links to human diseases, with which all have been associated except for the two most recently identified fibrillar collagens, type XXIV collagen and type XXVII collagen. To assess functions and potential disease phenotypes of type XXVII collagen, we examined its roles in zebrafish embryonic and post-embryonic development.We identified two type XXVII collagen genes in zebrafish, col27a1a and col27a1b. Both col27a1a and col27a1b were expressed in notochord and cartilage in the embryo and early larva. To determine sites of type XXVII collagen function, col27a1a and col27a1b were knocked down using morpholino antisense oligonucleotides. Knockdown of col27a1a singly or in conjunction with col27a1b resulted in curvature of the notochord at early stages and formation of scoliotic curves as well as dysmorphic vertebrae at later stages. These defects were accompanied by abnormal distributions of cells and protein localization in the notochord, as visualized by transmission electron microscopy, as well as delayed vertebral mineralization as detected histologically.Together, our findings indicate a key role for type XXVII collagen in notochord morphogenesis and axial skeletogenesis and suggest a possible human disease phenotype

    Gene expression and matrix turnover in overused and damaged tendons

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    Chronic, painful conditions affecting tendons, frequently known as tendinopathy, are very common types of sporting injury. The tendon extracellular matrix is substantially altered in tendinopathy, and these changes are thought to precede and underlie the clinical condition. The tendon cell response to repeated minor injuries or “overuse” is thought to be a major factor in the development of tendinopathy. Changes in matrix turnover may also be effected by the cellular response to physical load, altering the balance of matrix turnover and changing the structure and composition of the tendon. Matrix turnover is relatively high in tendons exposed to high mechanical demands, such as the supraspinatus and Achilles, and this is thought to represent either a repair or tissue maintenance function. Metalloproteinases are a large family of enzymes capable of degrading all of the tendon matrix components, and these are thought to play a major role in the degradation of matrix during development, adaptation and repair. It is proposed that some metalloproteinase enzymes are required for the health of the tendon, and others may be damaging, leading to degeneration of the tissue. Further research is required to investigate how these enzyme activities are regulated in tendon and altered in tendinopathy. A profile of all the metalloproteinases expressed and active in healthy and degenerate tendon is required and may lead to the development of new drug therapies for these common and debilitating sports injuries

    Ethnic differences in unemployment and ill health.

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    Objective The aim of the study is to evaluate whether health inequalities associated with unemployment are comparable across different ethnic groups. Method A random sample of inhabitants of the city of Rotterdam filled out a questionnaire on health and its determinants, with a response of 55.4% (n = 2,057). In a cross-sectional design the associations of unemployment, ethnicity, and individual characteristics with a perceived poor health were investigated with logistic regression analysis. The associations of these determinants with physical and mental health, measured by the Short Form 36 Health Survey, were evaluated with linear regression analyses. Interactions between ethnicity and unemployment were investigated to determine whether associations of unemployment and health differed across ethnic groups. Results Ill health was more common among unemployed persons [odd

    Het Rijksvaccinatieprogramma in Nederland. Ontwikkelingen in 2006

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    In 2006 several changes were made in the Dutch National Immunisation Programme (NIP): Hepatitis B vaccination at birth was added for children born to mothers positive for hepatitis B surface antigen; a new vaccine for diphtheria, tetanus, pertussis (a-cellular), poliomyelitis and Haemophilus influenzae (DTaP-IPV/Hib) was introduced; vaccination against pneumococcal disease was added at two, three, four and eleven months; risk groups for hepatitis B receive a combined vaccine for DTaP-IPV/Hib and HBV at the same ages; DT-IPV and aP at the age of four years were combined in one vaccine; and new MMR vaccines were introduced. As new information became available in 2006, the desirability to introduce vaccinations in the NIP for the following diseases could be (re)considered: hepatitis B (universal vaccination), rotavirus, varicella and human papillomavirus. For respiratory syncytial virus and meningococcal serogroup B disease no candidate vaccines are available yet. Extension of the programme with available vaccines for hepatitis A, influenza and tuberculosis is not (yet) recommended. The NIP in the Netherlands is effective and safe. However, continued monitoring of the effectiveness and safety of the NIP is important as changes are made regularly. Maintaining high vaccine uptake is vital to prevent (re)emergence of diseases. Furthermore, the programme should be regularly reviewed as new vaccines become available.In 2006 traden verschillende veranderingen op in het Rijksvaccinatieprogramma (RVP) in Nederland: kinderen die geboren worden uit moeders die chronisch geinfecteerd zijn met hepatitis B krijgen vlak na de geboorte een hepatitis B vaccinatie; er is een ander vaccin geintroduceerd voor difterie, kinkhoest (a-cellulair), tetanus, poliomyelitis en Haemophilus influenzae (DaKTP/Hib); vaccinatie tegen pneumokokken is toegevoegd op de leeftijd van 2, drie, vier en elf maanden; risicogroepen voor hepatitis B krijgen op diezelfde leeftijden een combinatievaccin voor DaKTP/Hib en hepatitis B; DTP en aK zijn gecombineerd in een vaccin op vierjarige leeftijd; en er zijn nieuwe BMR vaccins geintroduceerd. Op basis van informatie die in 2006 beschikbaar is gekomen wordt geadviseerd de introductie van vaccinaties voor de volgende ziekten te overwegen: hepatitis B (universele vaccinatie), rotavirus, waterpokken en humaan papillomavirus. Voor respiratoir syncytieel virus en meningokokken B zijn nog geen kandidaatvaccins beschikbaar en uitbreiding van het RVP met beschikbare vaccins voor hepatitis A, influenza en tuberculose wordt nog niet aanbevolen. Het RVP is effectief en veilig, maar voortdurende bewaking hiervan is groot belang, omdat er regelmatig veranderingen optreden. Handhaven van de hoge vaccinatiegraad is essentieel om terugkeer van ziekten te voorkomen. Verder moet regelmatig bekeken worden of het RVP aangepast moet worden aangezien er steeds nieuwe vaccins beschikbaar komen

    Proton Magnetic Resonance Spectroscopy in 22q11 Deletion Syndrome

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    OBJECTIVE: People with velo-cardio-facial syndrome or 22q11 deletion syndrome (22q11DS) have behavioral, cognitive and psychiatric problems. Approximately 30% of affected individuals develop schizophrenia-like psychosis. Glutamate dysfunction is thought to play a crucial role in schizophrenia. However, it is unknown if and how the glutamate system is altered in 22q11DS. People with 22q11DS are vulnerable for haploinsufficiency of PRODH, a gene that codes for an enzyme converting proline into glutamate. Therefore, it can be hypothesized that glutamatergic abnormalities may be present in 22q11DS. METHOD: We employed proton magnetic resonance spectroscopy ((1)H-MRS) to quantify glutamate and other neurometabolites in the dorsolateral prefrontal cortex (DLPFC) and hippocampus of 22 adults with 22q11DS (22q11DS SCZ+) and without (22q11DS SCZ-) schizophrenia and 23 age-matched healthy controls. Also, plasma proline levels were determined in the 22q11DS group. RESULTS: We found significantly increased concentrations of glutamate and myo-inositol in the hippocampal region of 22q11DS SCZ+ compared to 22q11DS SCZ-. There were no significant differences in levels of plasma proline between 22q11DS SCZ+ and 22q11DS SCZ-. There was no relationship between plasma proline and cerebral glutamate in 22q11DS. CONCLUSION: This is the first in vivo(1)H-MRS study in 22q11DS. Our results suggest vulnerability of the hippocampus in the psychopathology of 22q11DS SCZ+. Altered hippocampal glutamate and myo-inositol metabolism may partially explain the psychotic symptoms and cognitive impairments seen in this group of patients
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