6,280 research outputs found

    Genetic Influences on Incidence and Case-Fatality of Infectious Disease

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    BACKGROUND: Family, twin and adoption studies suggest that genetic susceptibility contributes to familial aggregation of infectious diseases or to death from infections. We estimated genetic and shared environmental influences separately on the risk of acquiring an infection (incidence) and on dying from it (case fatality). METHODS: Genetic influences were estimated by the association between rates of hospitalization for infections and between case-fatality rates of adoptees and their biological full- and half- siblings. Familial environmental influences were investigated in adoptees and their adoptive siblings. Among 14,425 non-familial adoptions, granted in Denmark during the period 1924-47, we selected 1,603 adoptees, who had been hospitalized for infections and/or died with infection between 1977 and 1993. Their siblings were considered predisposed to infection, and compared with non-predisposed siblings of randomly selected 1,348 adoptees alive in 1993 and not hospitalized for infections in the observation period. The risk ratios presented were based on a Cox regression model. RESULTS: Among 9971 identified siblings, 2829 had been hospitalised for infections. The risk of infectious disease was increased among predisposed compared with non-predisposed in both biological (1.18; 95% confidence limits 1.03-1.36) and adoptive siblings (1.23; 0.98-1.53). The risk of a fatal outcome of the infections was strongly increased (9.36; 2.94-29.8) in biological full siblings, but such associations were not observed for the biological half siblings or for the adoptive siblings. CONCLUSION: Risk of getting infections appears to be weakly influenced by both genetically determined susceptibility to infection and by family environment, whereas there appears to be a strong non-additive genetic influence on risk of fatal outcome

    Retinal glycoprotein enrichment by concanavalin a enabled identification of novel membrane autoantigen synaptotagmin-1 in equine recurrent uveitis.

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    Complete knowledge of autoantigen spectra is crucial for understanding pathomechanisms of autoimmune diseases like equine recurrent uveitis (ERU), a spontaneous model for human autoimmune uveitis. While several ERU autoantigens were identified previously, no membrane protein was found so far. As there is a great overlap between glycoproteins and membrane proteins, the aim of this study was to test whether pre-enrichment of retinal glycoproteins by ConA affinity is an effective tool to detect autoantigen candidates among membrane proteins. In 1D Western blots, the glycoprotein preparation allowed detection of IgG reactions to low abundant proteins in sera of ERU patients. Synaptotagmin-1, a Ca2+-sensing protein in synaptic vesicles, was identified as autoantigen candidate from the pre-enriched glycoprotein fraction by mass spectrometry and was validated as a highly prevalent autoantigen by enzyme-linked immunosorbent assay. Analysis of Syt1 expression in retinas of ERU cases showed a downregulation in the majority of ERU affected retinas to 24%. Results pointed to a dysregulation of retinal neurotransmitter release in ERU. Identification of synaptotagmin-1, the first cell membrane associated autoantigen in this spontaneous autoimmune disease, demonstrated that examination of tissue fractions can lead to the discovery of previously undetected novel autoantigens. Further experiments will address its role in ERU pathology

    A simulation model of the Devils Hole pupfish population using monthly length-frequency distributions

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    The Devils Hole pupfish, Cyprinodon diabolis, is a federally-endangered fish that is endemic to Devils Hole, a discontiguous part of Death Valley National Park in Nye County, Nevada. Due to its status, Devils Hole pupfish monitoring must be non-obtrusive and thereby exclude techniques that require handling fish. Due to a recent decline in pupfish abundance, Devils Hole pupfish managers have expressed a need for a model that describes population dynamics. This population model would be used to identify vulnerable life history stage(s) and inform management actions. We constructed a set of individualbased simulation models designed to explore effects of population processes and evaluate assumptions. We developed a baseline model, whose output best resembled both observed length-frequency data and predicted intraannual abundance patterns. We then ran simulations with 5 % increases in egg-larval, juvenile, and adult survival rates to better understand Devils Hole pupfish life history, thereby helping identify vulnerable life history stages that should become the target of management actions. Simulation models with temporally constant adult, juvenile, and egg-larval survival rates were able to reproduce observed length-frequency distributions and predicted intra-annual population patterns. In particular, models with monthly adult and juvenile survival rates of 80 % and an egg-larval survival rate of 4.7 % replicated patterns in observed data. Population growth was most affected by 5 % increases in egg-larval survival, whereas adult and juvenile survival rates had similar but lesser effects on population growth. Outputs from the model were used to assess factors suspected of influencing Devils Hole pupfish population decline

    Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

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    Background Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded. Methods We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis. Findings Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis. Conclusion Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice

    Emotion based attentional priority for storage in visual short-term memory

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    A plethora of research demonstrates that the processing of emotional faces is prioritised over non-emotive stimuli when cognitive resources are limited (this is known as ‘emotional superiority’). However, there is debate as to whether competition for processing resources results in emotional superiority per se, or more specifically, threat superiority. Therefore, to investigate prioritisation of emotional stimuli for storage in visual short-term memory (VSTM), we devised an original VSTM report procedure using schematic (angry, happy, neutral) faces in which processing competition was manipulated. In Experiment 1, display exposure time was manipulated to create competition between stimuli. Participants (n = 20) had to recall a probed stimulus from a set size of four under high (150 ms array exposure duration) and low (400 ms array exposure duration) perceptual processing competition. For the high competition condition (i.e. 150 ms exposure), results revealed an emotional superiority effect per se. In Experiment 2 (n = 20), we increased competition by manipulating set size (three versus five stimuli), whilst maintaining a constrained array exposure duration of 150 ms. Here, for the five-stimulus set size (i.e. maximal competition) only threat superiority emerged. These findings demonstrate attentional prioritisation for storage in VSTM for emotional faces. We argue that task demands modulated the availability of processing resources and consequently the relative magnitude of the emotional/threat superiority effect, with only threatening stimuli prioritised for storage in VSTM under more demanding processing conditions. Our results are discussed in light of models and theories of visual selection, and not only combine the two strands of research (i.e. visual selection and emotion), but highlight a critical factor in the processing of emotional stimuli is availability of processing resources, which is further constrained by task demands

    Pharmacokinetic and technical comparison of Sandostatin® LAR® and other formulations of long-acting octreotide

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    <p>Abstract</p> <p>Background</p> <p>Sandostatin<sup>® </sup>LAR<sup>® </sup>(Novartis Pharma AG) is a long-acting repeatable formulation of the somatostatin analogue octreotide, the safety and efficacy of which has been established through 15 years of clinical experience. Recently, other formulations of octreotide using polymer poly(lactic-co-glycolic acid) technology have been developed. This study compares the composition and pharmacokinetic (PK) profile of Sandostatin LAR with three other versions of the depot delivery system (formulations A, B and C, available in selected countries).</p> <p>Findings</p> <p>Sandostatin LAR exhibited a characteristic concentration-time profile with a limited initial release of octreotide ('burst'), an erosion phase from weeks 3-5, and a slowly declining concentration to day 52. The PK profiles of formulations A and B were characterized by a large initial burst during days 0-2, with up to 41% of the overall area under the plasma-concentration time curve achieved. Low and variable octreotide concentrations were observed during the microparticle erosion phase (days 2-62 [day 82 formulation C]) for formulations A, B and C. Sandostatin LAR microparticles are spherical in shape with an average diameter of approximately 50 μm, determined by scanning electron microscopy evaluation. Formulation A had smaller, irregular microparticles, and formulations B and C exhibited a large range of particle diameters (< 20 to > 100 μm). Inductively coupled plasma-optical emission spectroscopy detected a high tin content of 104 mg/kg in formulation B, the presence of which may suggest inadequate purification following polymer synthesis using tin(II)-octoate as catalyst. PK profiles for formulations A, B and C after a single intramuscular injection of 4 mg/kg in male New Zealand rabbits differed markedly from the PK profile of Sandostatin LAR.</p> <p>Conclusions</p> <p>Clear differences were seen between Sandostatin LAR and formulations A, B and C, including variations in microparticle size, shape and impurity content. Considering the significant differences in the octreotide release profile between Sandostatin LAR and the other formulations, the safety and efficacy of the other formulations cannot be inferred from the Sandostatin LAR efficacy and safety profile; each of these other formulations should be assessed accordingly.</p

    Sunscreens - Which and what for?

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    It is well established that sun exposure is the main cause for the development of skin cancer. Chronic continuous UV radiation is believed to induce malignant melanoma, whereas intermittent high-dose UV exposure contributes to the occurrence of actinic keratosis as precursor lesions of squamous cell carcinoma as well as basal cell carcinoma. Not only photocarcinogenesis but also the mechanisms of photoaging have recently become apparent. In this respect the use of sunscreens seemed to prove to be more and more important and popular within the last decades. However, there is still inconsistency about the usefulness of sunscreens. Several studies show that inadequate use and incomplete UV spectrum efficacy may compromise protection more than previously expected. The sunscreen market is crowded by numerous products. Inorganic sunscreens such as zinc oxide and titanium oxide have a wide spectral range of activity compared to most of the organic sunscreen products. It is not uncommon for organic sunscreens to cause photocontact allergy, but their cosmetic acceptability is still superior to the one given by inorganic sunscreens. Recently, modern galenic approaches such as micronization and encapsulation allow the development of high-quality inorganic sunscreens. The potential systemic toxicity of organic sunscreens has lately primarily been discussed controversially in public, and several studies show contradictory results. Although a matter of debate, at present the sun protection factor (SPF) is the most reliable information for the consumer as a measure of sunscreen filter efficacy. In this context additional tests have been introduced for the evaluation of not only the protective effect against erythema but also protection against UV-induced immunological and mutational effects. Recently, combinations of UV filters with agents active in DNA repair have been introduced in order to improve photoprotection. This article reviews the efficacy of sunscreens in the prevention of epithelial and nonepithelial skin cancer, the effect on immunosuppression and the value of the SPF as well as new developments on the sunscreen market. Copyright (C) 2005 S. Karger AG, Basel
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