111 research outputs found

    Laforin, a Dual Specificity Phosphatase Involved in Lafora Disease, Is Present Mainly as Monomeric Form with Full Phosphatase Activity

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    Lafora Disease (LD) is a fatal neurodegenerative epileptic disorder that presents as a neurological deterioration with the accumulation of insoluble, intracellular, hyperphosphorylated carbohydrates called Lafora bodies (LBs). LD is caused by mutations in either the gene encoding laforin or malin. Laforin contains a dual specificity phosphatase domain and a carbohydrate-binding module, and is a member of the recently described family of glucan phosphatases. In the current study, we investigated the functional and physiological relevance of laforin dimerization. We purified recombinant human laforin and subjected the monomer and dimer fractions to denaturing gel electrophoresis, mass spectrometry, phosphatase assays, protein-protein interaction assays, and glucan binding assays. Our results demonstrate that laforin prevalently exists as a monomer with a small dimer fraction both in vitro and in vivo. Of mechanistic importance, laforin monomer and dimer possess equal phosphatase activity, and they both associate with malin and bind glucans to a similar extent. However, we found differences between the two states' ability to interact simultaneously with malin and carbohydrates. Furthermore, we tested other members of the glucan phosphatase family. Cumulatively, our data suggest that laforin monomer is the dominant form of the protein and that it contains phosphatase activity

    Modelling survival : exposure pattern, species sensitivity and uncertainty

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    The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans

    Impact of climate change on weeds in agriculture: a review

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    Genomic reconstruction of the SARS-CoV-2 epidemic in England.

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    The evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus leads to new variants that warrant timely epidemiological characterization. Here we use the dense genomic surveillance data generated by the COVID-19 Genomics UK Consortium to reconstruct the dynamics of 71 different lineages in each of 315 English local authorities between September 2020 and June 2021. This analysis reveals a series of subepidemics that peaked in early autumn 2020, followed by a jump in transmissibility of the B.1.1.7/Alpha lineage. The Alpha variant grew when other lineages declined during the second national lockdown and regionally tiered restrictions between November and December 2020. A third more stringent national lockdown suppressed the Alpha variant and eliminated nearly all other lineages in early 2021. Yet a series of variants (most of which contained the spike E484K mutation) defied these trends and persisted at moderately increasing proportions. However, by accounting for sustained introductions, we found that the transmissibility of these variants is unlikely to have exceeded the transmissibility of the Alpha variant. Finally, B.1.617.2/Delta was repeatedly introduced in England and grew rapidly in early summer 2021, constituting approximately 98% of sampled SARS-CoV-2 genomes on 26 June 2021

    What are the preferences of health care professionals in Germany regarding fully liquid, ready-to-use hexavalent pediatric vaccine versus hexavalent pediatric vaccine that needs reconstitution?

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    Andrew J Lloyd,1 Beenish Nafees,1 Eddy Ziani,2 Laurence Nicolas,2 Beth Alice Fordham,1 Benoit Soubeyrand,2 Christoph Bornhöft3 1Patient Reported Outcomes, ICON Plc, Oxford, UK; 2Medical Affairs, Sanofi Pasteur MSD, Lyon, France; 3Practice for Pediatric and Adolescent Medicine, Bensheim, Germany Abstract: Diphtheria, tetanus and acellular pertussis (DTaP) based combined vaccines have led to significant reduction in incidence of several serious pediatric infectious diseases. A new, fully liquid combined hexavalent vaccine has been introduced and has been shown to reduce administration time. This fully liquid vaccine may also be simpler to administer and could reduce handling errors. The present study was designed to understand the value that health care providers (HCPs) place on aspects of injection devices for combined hexavalent vaccine programs in Germany. A discrete choice experiment (DCE) was designed to elicit the views of HCPs regarding hexavalent vaccines. The key attributes of injection devices were identified through a focused literature search and interviews with HCPs. Five key attributes, each with two or three levels were described which included: type of device, experience of this hexavalent vaccine on the German market, preparation time, probability of handling errors, and dosage errors. Physicians (n=150) and nurses (n=150) who administered hexavalent vaccines in Germany completed the survey. Choice data were analyzed using the conditional logit procedure. All attributes were significant and important independent influences on physicians’ and nurses’ choices. Reducing any “probability of dosage errors” was the most important attribute. Both physicians and nurses had a strong preference to reduce preparation time. All other things equal both groups also significantly preferred a fully liquid hexavalent vaccine. They also preferred vaccines that had been on the market for a few years compared to ones that had not (especially the physicians). Additional analyses explored participants’ preferences in more detail through interaction terms. The DCE choice data provide useful insights into how HCPs view each aspect of the vaccination device. Overall, the HCPs preferred fully liquid vaccines. The survey also highlighted the importance of handling and dosage errors, reducing preparation time, and also experience of the HCPs with the use of a vaccine. The survey work included physicians and nurses and explored their views separately. Keywords: hexavalent vaccines, fully liquid vaccines, preferences, handling errors, dosage error

    Health state utility valuation in radioactive iodine-refractory differentiated thyroid cancer

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    Beth A Fordham,1 Cicely Kerr,1 Hayley M de Freitas,1 Andrew J Lloyd,1 Karissa Johnston,2 Corey L Pelletier,3 Gabriel Tremblay,3 Anna Forsythe,3 Bryan McIver,4 Ezra EW Cohen5 1ICON Patient Reported Outcomes, Oxford, UK; 2ICON Epidemiology, Toronto, ON, Canada; 3Eisai Inc., NJ, 4Moffitt Cancer Center, FL, 5University of California San Diego Moores Cancer Center, La Jolla, CA, USA Purpose: The aim of this study was to elicit utilities for radioactive iodine-refractory differentiated thyroid cancer (RR-DTC) and evaluate the impact of treatment response and toxicities on quality of life.Patients and methods: RR-DTC health states were developed based on data from a previous qualitative study and iterative review by clinical experts. Following piloting, health states underwent valuation by 100 members of the UK public during time trade-off interviews. Mean utilities and descriptive distribution statistics were calculated, and a logistic regression analysis was conducted.Results: The demographic characteristics of the study sample were generally reflective of the UK population. Clear differentiation in valuation between health states was observed. No response/stable disease had an adjusted utility value of 0.87, with a corresponding gain of +0.04 following a treatment response and a decline of –0.35 for disease progression. Adverse events were associated with utility decrements between –0.47 (grade III diarrhea) and –0.05 (grade I/II alopecia).Conclusion: The trade-off interviews derived utility weights show clear differentiation between RR-DTC health states in response to treatment. The values reported in this study are suitable for cost-effectiveness evaluations for new treatments in RR-DTC. Keywords: differentiated thyroid cancer, radioactive iodine-refractory, health-related quality of life, health utility, vignett

    Nutritional Deficiencies and Food Insecurity Among HIV-infected Children in Tanzania

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    Background: Poor nutrition has been associated with impaired immunity and accelerated disease progression in HIV- infected children. The aim of this study was to quantify the levels of nutrient intake in HIV-infected children and compare these to standard recommendations. Methods: We surveyed HIV-infected Tanzanian children enrolled in a pediatric care program that provided routine nutritional counseling and vitamin supplementation. We obtained anthropometric measurements and determined 24-hour macronutrient and micronutrient intakes and food insecurity. Values were compared to recommended nutrient intakes based on age and gender. Results: We interviewed 48 pairs of children and their caregiver(s). The age of the child ranged from 2-14 years; median age 6 and 60% female. The median weight-for-height z-score for children ≤ 5 years was 0.69 and BMI-for-age z-scores for children >5 was -0.84. Macronutrient evaluation showed that 29 (60%) children were deficient in dietary intake of energy; deficiency was more common in older children (p=0.004). Micronutrient evaluation shows that over half of study subjects were deficient in dietary intake of vitamin A, vitamin D, vitamin E, thiamine, riboflavin, niacin, folate, vitamin B12, and calcium. Food insecurity was reported by 20 (58%) caregivers. Conclusions and Public Health Implications: The diets of many HIV-infected children at a specialized treatment center in Tanzania do not meet recommended levels of macro- and micro-nutrients. Food insecurity was a contributory factor. Enhanced dietary counseling and provision of macro- and micro-nutrient supplements will be necessary to achieve optimal nutrition for most HIV-infected children in resource-poor regions

    Nutritional Deficiencies and Food Insecurity Among HIV-infected Children in Tanzania

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    Background: Poor nutrition has been associated with impaired immunity and accelerated disease progression in HIV- infected children. The aim of this study was to quantify the levels of nutrient intake in HIV-infected children and compare these to standard recommendations. Methods: We surveyed HIV-infected Tanzanian children enrolled in a pediatric care program that provided routine nutritional counseling and vitamin supplementation. We obtained anthropometric measurements and determined 24-hour macronutrient and micronutrient intakes and food insecurity. Values were compared to recommended nutrient intakes based on age and gender. Results: We interviewed 48 pairs of children and their caregiver(s). The age of the child ranged from 2-14 years; median age 6 and 60% female. The median weight-for-height z-score for children ≤ 5 years was 0.69 and BMI-for-age z-scores for children >5 was -0.84. Macronutrient evaluation showed that 29 (60%) children were deficient in dietary intake of energy; deficiency was more common in older children (p=0.004). Micronutrient evaluation shows that over half of study subjects were deficient in dietary intake of vitamin A, vitamin D, vitamin E, thiamine, riboflavin, niacin, folate, vitamin B12, and calcium. Food insecurity was reported by 20 (58%) caregivers. Conclusions and Public Health Implications: The diets of many HIV-infected children at a specialized treatment center in Tanzania do not meet recommended levels of macro- and micro nutrients. Food insecurity was a contributory factor. Enhanced dietary counseling and provision of macro- and micro-nutrient supplements will be necessary to achieve optimal nutrition for most HIV-infected children in resource-poor regions. Keywords: HIV • Tanzania • Children • Energy Intake • Food Insecurity • Micronutrients Copyright © 2014 Modlin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
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