579 research outputs found

    Aspects of the quantitative separation and estimation of thiamine and its phosphate esters : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University

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    Methods for the separation and estimation of thiamine, thiamine monophosphate and thiamine diphosphate which would be applicable to biological extracts were investigated. Two methods for the estimation of thiamine were compared, the acid dye method and the thiochrome method. The thiochrome method was preferred as the acid dye method was more difficult to perform and some interference by certain amino acids was indicated. As both methods only estimate free thiamine, the optimum conditions for hydrolysis of thiamine phosphate esters by wheat germ acid phosphatase were also investigated. High phosphatase concentrations in the digestion mixture interfered with the extraction of thiochrome, by isobutanol, after oxidation of the free thiamine produced. Variation of the buffer in which the digestion was performed also affected the recoveries obtained. The inclusion of magnesium ions in the digestion mixture increased the activity of the enzyme so that it was possible to use an amount of phosphatase which was low enough to avoid interference with the extraction of thiochrome but which was sufficient to completely hydrolyse thiamine phosphate esters. The presence of magnesium ions also prevented the interference observed when formate rather than acetate buffers were used in the digestion mixture. A variety of separation techniques were investigated. Compared to paper and thin layer chromatography, high voltage paper electrophoresis (at 3kV in pH 3.5 buffer) gave the best and quickest separations. However only a 60% recovery was obtained after samples were eluted from the paper with 0.1M hydrochloric acid. Separation was achieved by elution of the thiochrome derivatives of thiamine, TMP and TDP from Sephadex G10 gel. Recoveries, estimated spectrophotometrically, indicated that this method could be used for the quantitative separation of thiamine and its phosphate esters. However since the method does not allow concentration of samples, it would be unsuitable for the estimation of biological extracts. Separation of thiamine and its esters using three ion exchange resins was also investigated. Partial separation of thiamine and its phosphate esters was obtained with Amberlite GC50 resin, the separation being determined by the form of the resin used. The hydrogen form of the resin allowed separation between TDP and thiamine-TMP while the sodium form separated thiamine from TMP-TDP. Neither form of the resin bound TDP firmly even when water was used as the eluent, so that separation of TDP and TTP would not be possible. Separation was attempted by eluting samples from Dowex 1-X8 resin with formate buffers of increasing ionic strength or pH. While the separation of thiamine, TMP and TDP appeared to be complete, by the elution profile, it was found that sample breakdown occurred. Electrophoresis of the eluted samples showed that the only peak which contained a single component was that corresponding to thiamine. Sample break-down was further indicated by a low recovery obtained when a sample containing only TDP was eluted. Identification of the peak contaminants was attempted using high voltage electrophoresis but proved difficult due to salt retardation affecting the positions of the peak components after electrophoresis. With Dowex 50 resin TDP and TMP were easily separated and eluted with ammonium acetate buffer of varying pH and ionic strength but the elution of thiamine required high pH or ionic strength solutions. Sample breakdown also appeared to occur on elution of samples from the resin. When TMP and TDP were eluted, separation appeared to be complete but a recovery of greater than 100% was obtained for TMP and both eluted compounds exhibited a progressive breakdown after elution. Sample breakdown was particularly notable when thiamine alone was eluted as 2 peaks were eluted and, after oxidation, yellow fluorescent material as well as the usual blue (characteristic of thiochrome) was observed. Characterisation of the yellow fluorescent compound(s) was attempted using electrophoresis, ultra-violet spectra and fluorescent spectra and it was found to be similar, but not identical, to thiamine

    Supporting Aboriginal Community Controlled Health Services to deliver alcohol care : Protocol for a cluster randomised controlled trial

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    Introduction Indigenous peoples who have experienced colonisation or oppression can have a higher prevalence of alcohol-related harms. In Australia, Aboriginal Community Controlled Health Services (ACCHSs) offer culturally accessible care to Aboriginal and Torres Strait Islander (Indigenous) peoples. However there are many competing health, socioeconomic and cultural client needs. Methods and analysis A randomised cluster wait-control trial will test the effectiveness of a model of tailored and collaborative support for ACCHSs in increasing use of alcohol screening (with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C)) and of treatment provision (brief intervention, counselling or relapse prevention medicines). Setting Twenty-two ACCHSs across Australia. Randomisation Services will be stratified by remoteness, then randomised into two groups. Half receive support soon after the trial starts (intervention or ‘early support’); half receive support 2 years later (wait-control or ‘late support’). The support Core support elements will be tailored to local needs and include: support to nominate two staff as champions for increasing alcohol care; a national training workshop and bimonthly teleconferences for service champions to share knowledge; onsite training, and bimonthly feedback on routinely collected data on screening and treatment provision. Outcomes and analysis Primary outcome is use of screening using AUDIT-C as routinely recorded on practice software. Secondary outcomes are recording of brief intervention, counselling, relapse prevention medicines; and blood pressure, gamma glutamyltransferase and HbA1c. Multi-level logistic regression will be used to test the effectiveness of support. Ethics and dissemination Ethical approval has been obtained from eight ethics committees: the Aboriginal Health and Medical Research Council of New South Wales (1217/16); Central Australian Human Research Ethics Committee (CA-17-2842); Northern Territory Department of Health and Menzies School of Health Research (2017-2737); Central Queensland Hospital and Health Service (17/QCQ/9); Far North Queensland (17/QCH/45-1143); Aboriginal Health Research Ethics Committee, South Australia (04-16-694); St Vincent’s Hospital (Melbourne) Human Research Ethics Committee (LRR 036/17); and Western Australian Aboriginal Health Ethics Committee (779). Trial registration number ACTRN12618001892202; Pre-results

    Neurodevelopmental outcomes at 7 years’ corrected age in preterm infants who were fed high-dose docosahexaenoic acid to term equivalent: a follow-up of a randomised controlled trial

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    This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work noncommercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http:// creativecommons.org/licenses/by-nc/4.0/OBJECTIVE: To determine if improvements in cognitive outcome detected at 18 months' corrected age (CA) in infants born <33 weeks' gestation receiving a high-docosahexaenoic acid (DHA) compared with standard-DHA diet were sustained in early childhood. DESIGN: Follow-up of a multicentre randomised controlled trial. Randomisation was stratified for sex, birth weight (<1250 vs ≥1250 g) and hospital. SETTING: Five Australian tertiary hospitals from 2008 to 2013. PARTICIPANTS: 626 of the 657 participants randomised between 2001 and 2005 were eligible to participate. INTERVENTIONS: High-DHA (≈1% total fatty acids) enteral feeds compared with standard-DHA (≈0.3% total fatty acids) from age 2-4 days until term CA. PRIMARY OUTCOME: Full Scale IQ of the Wechsler Abbreviated Scale of Intelligence (WASI) at 7 years CA. Prespecified subgroup analyses based on the randomisation strata (sex, birth weight) were conducted. RESULTS: 604 (92% of the 657 originally randomised) consented to participate (291 high-DHA, 313 standard-DHA). To address missing data in the 604 consenting participants (22 for primary outcome), multiple imputation was performed. The Full Scale IQ was not significantly different between groups (high-DHA 98.3, SD 14.0, standard-DHA 98.5, SD 14.9; mean difference adjusted for sex, birthweight strata and hospital -0.3, 95% CI -2.9 to 2.2; p=0.79). There were no significant differences in any secondary outcomes. In prespecified subgroup analyses, there was a significant sex by treatment interaction on measures of parent-reported executive function and behaviour. Scores were within the normal range but girls receiving the high-DHA diet scored significantly higher (poorer outcome) compared with girls receiving the standard-DHA diet. CONCLUSIONS: Supplementing the diets of preterm infants with a DHA dose of approximately 1% total fatty acids from days 2-4 until term CA showed no evidence of benefit at 7 years' CA. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry: ACTRN12606000327583

    Critical Care Units in Malawi: A Cross-Sectional Study

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    Background: The global burden of critical illness falls disproportionately outside high-income countries. Despite younger patient populations with similar or lower disease severity, critical illness outcomes are poor outside high-income countries. A lack of data limits attempts to understand and address the drivers of critical care outcomes outside high-income countries. Objectives: We aim to characterize the organization, available resources, and service capacity of public sector critical care units in Malawi and identify barriers to improving care. Methods: We conducted a secondary analysis of the Malawi Emergency and Critical Care Survey, a cross-sectional study performed from January to February 2020 at all four central hospitals and a simple random sample of nine out of 24 public sector district hospitals in Malawi, a predominantly rural, low-income country of 19.6 million in southern Africa. Data from critical care units were used to characterize resources, processes, and barriers to care. Findings: There were four HDUs and four ICUs across the 13 hospitals in the Malawi Emergency and Critical Care Survey sample. The median critical care beds per 1,000,000 catchment was 1.4 (IQR: 0.9 to 6.7). Absent equipment was the most common barrier in HDUs (46% [95% CI: 32% to 60%]). Stockouts was the most common barriers in ICUs (48% [CI: 38% to 58%]). ICUs had a median 3.0 (range: 2 to 8) functional ventilators per unit and reported an ability to perform several quality mechanical ventilation interventions. Conclusions: Although significant gaps exist, Malawian critical care units report the ability to perform several complex clinical processes. Our results highlight regional inequalities in access to care and support the use of process-oriented questions to assess critical care capacity. Future efforts should focus on basic critical care capacity outside of urban areas and quantify the impact of context-specific variables on critical care mortality

    International consensus guidelines for the diagnosis and management of food protein–induced enterocolitis syndrome: Executive summary—Workgroup Report of the Adverse Reactions to Foods Committee, American Academy of Allergy, Asthma & Immunology

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    Food protein-induced enterocolitis (FPIES) is a non-IgE cell- mediated food allergy that can be severe and lead to shock. Despite the potential seriousness of reactions, awareness of FPIES is low; high-quality studies providing insight into the pathophysiology, diagnosis, and management are lacking; and clinical outcomes are poorly established. This consensus document is the result of work done by an international workgroup convened through the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology and the International FPIES Association advocacy group. These are the first international evidence-based guidelines to improve the diagnosis and management of patients with FPIES. Research on prevalence, pathophysiology, diagnostic markers, and future treatments is necessary to improve the care of patients with FPIES. These guidelines will be updated periodically as more evidence becomes available

    Internal validation of STRmix™ – A multi laboratory response to PCAST

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    We report a large compilation of the internal validations of the probabilistic genotyping software STRmixâ„¢. Thirty one laboratories contributed data resulting in 2825 mixtures comprising three to six donors and a wide range of multiplex, equipment, mixture proportions and templates. Previously reported trends in the LR were confirmed including less discriminatory LRs occurring both for donors and non-donors at low template (for the donor in question) and at high contributor number. We were unable to isolate an effect of allelic sharing. Any apparent effect appears to be largely confounded with increased contributor number

    Attenuating Effect of Vigorous Physical Activity on the Risk for Inherited Obesity: A Study of 47,691 Runners

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    Objective: Physical activity has been shown to attenuate the effect of the FTO polymorphism on body weight, and the heritability of body weight in twin and in family studies. The dose-response relationship between activity and the risk for inherited obesity is not well known, particularly for higher doses of vigorous exercise. Such information is needed to best prescribe an exercise dose for obesity prevention in those at risk due to their family history. Design: We therefore analyzed self-reported usual running distance, body mass index (BMI), waist circumference, and mother’s and father’s adiposity (1 = lean, 2 = normal, 3 = overweight, and 4 = very overweight) from survey data collected on 33,480 male and 14,211 female runners. Age-, education-, and alcohol-adjusted regression analyses were used to estimate the contribution of parental adiposities to the BMI and waist circumferences in runners who ran an average of,3, 3–6, 6–9, 9km/day.Results:BMIandwaistcircumferencesofrunnerswhoran,3km/dayweresignificantlyrelatedtotheirparentsadiposity(P,10215andP,10211,respectively).Theserelationships(i.e.,kg/m2orcmperincrementinparentaladiposity)diminishedsignificantlywithincreasingrunningdistanceforbothBMI(inheritance6exerciseinteraction,males:P,10210;females:P,1025)andwaistcircumference(inheritance6exerciseinteraction,males:P,1029;females:P=0.004).Comparedto,3km/day,theparentalcontributiontorunnerswhoaveraged9 km/day. Results: BMI and waist circumferences of runners who ran,3 km/day were significantly related to their parents adiposity (P,10 215 and P,10 211, respectively). These relationships (i.e., kg/m 2 or cm per increment in parental adiposity) diminished significantly with increasing running distance for both BMI (inheritance6exercise interaction, males: P,10 210; females: P,10 25) and waist circumference (inheritance6exercise interaction, males: P,10 29; females: P = 0.004). Compared to,3 km/day, the parental contribution to runners who averaged 9 km/day was diminished by 48 % for male BMI, 58 % for female BMI, 55 % for male waist circumference, and 58 % for female waist circumference. These results could not b

    Franchises lost and gained: post-coloniality and the development of women’s rights in Canada

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    The Canadian constitution is to some extent characterised by its focus on equality, and in particular gender equality. This development of women’s rights in Canada and the greater engagement of women as political actors is often presented as a steady linear process, moving forwards from post-enlightenment modernity. This article seeks to disturb this ‘discourse of the continuous,’ by using an analysis of the pre-confederation history of suffrage in Canada to both refute a simplistic linear view of women’s rights development and to argue for recognition of the Indigenous contribution to the history of women’s rights in Canada. The gain of franchise and suffrage movements in Canada in the late nineteenth and early twentieth century are, rightly, the focus of considerable study (Pauker 2015), This article takes an alternative perspective. Instead, it examines the exercise of earlier franchises in pre-confederation Canada. In particular it analyses why franchise was exercised more widely in Lower Canada and relates this to the context of the removal of franchises from women prior to confederation
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