983 research outputs found

    Structure of a rabbit muscle fructose-1,6-bisphosphate aldolase A dimer variant

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    The X-ray crystallographic structure of a dimer variant of fructose-1,6-bisphosphate aldolase demonstrates a stable oligomer that mirrors half of the native tetramer. The presence of product demonstrates that this is an active form

    Quinidine-Induced Immune Thrombocytopenia

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    We have identified six cases of quinidine-induced immune thrombocytopenia based on clinical evidence and in association with elevated amounts of platelet surface IgG. The degree of thrombocytopenia did not correlate with severity of clinical symptoms, nor did it predict the amount of IgG on the platelet surface. Three of the patients recovered promptly after drug discontinuation alone whereas the other patients received additional corticosteroid therapy. The clinical presentation, mode of diagnosis, and therapeutic considerations in the treatment of drug-induced thrombocytopenia are discussed

    Working towards consensus on methods used to elicit participant-reported safety data in uncomplicated malaria clinical drug studies: a Delphi technique study

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    BACKGROUND: Eliciting adverse event (AE) and non-study medication data reports from clinical research participants is integral to evaluating drug safety. However, using different methods to question participants yields inconsistent results, compromising the interpretation, comparison and pooling of data across studies. This is particularly important given the widespread use of anti-malarials in vulnerable populations, and their increasing use in healthy, but at-risk individuals, as preventive treatment or to reduce malaria transmission. METHODS: Experienced and knowledgeable anti-malarial drug clinical researchers were invited to participate in a Delphi technique study, to facilitate consensus on what are considered optimal (relevant, important and feasible) methods, tools, and approaches for detecting participant-reported AE and non-study medication data in uncomplicated malaria treatment studies. RESULTS: Of 72 invited, 25, 16 and 10 panellists responded to the first, second and third rounds of the Delphi, respectively. Overall, 68% (68/100) of all questioning items presented for rating achieved consensus. When asking general questions about health, panellists agreed on the utility of a question/concept about any change in health, taking care to ensure that such questions/concepts do not imply causality. Eighty-nine percent (39/44) of specific signs and symptoms questions were rated as optimal. For non-study medications, a general question and most structured questioning items were considered an optimal approach. The use of mobile phones, patient diaries, rating scales as well as openly engaging with participants to discuss concerns were also considered optimal complementary data-elicitation tools. CONCLUSIONS: This study succeeded in reaching consensus within a section of the anti-malarial drug clinical research community about using a general question concept, and structured questions for eliciting data about AEs and non-study medication reports. The concepts and items considered in this Delphi to be relevant, important and feasible should be further investigated for potential inclusion in a harmonized approach to collect participant-elicited anti-malarial drug safety data. This, in turn, should improve understanding of anti-malarial drug safety

    Encoded loop-lanthanide-binding tags for long-range distance measurements in proteins by NMR and EPR spectroscopy

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    We recently engineered encodable lanthanide binding tags (LBTs) into proteins and demonstrated their applicability in Nuclear Magnetic Resonance (NMR) spectroscopy, X-ray crystallography and luminescence studies. Here, we engineered two-loop-LBTs into the model protein interleukin-1β (IL1β) and measured [superscript 1]H, [superscript 15]N-pseudocontact shifts (PCSs) by NMR spectroscopy. We determined the Δχ-tensors associated with each Tm[superscript 3+]-loaded loop-LBT and show that the experimental PCSs yield structural information at the interface between the two metal ion centers at atomic resolution. Such information is very valuable for the determination of the sites of interfaces in protein–protein-complexes. Combining the experimental PCSs of the two-loop-LBT construct IL1β-S2R2 and the respective single-loop-LBT constructs IL1β-S2, IL1β-R2 we additionally determined the distance between the metal ion centers. Further, we explore the use of two-loop LBTs loaded with Gd[superscript 3+] as a novel tool for distance determination by Electron Paramagnetic Resonance spectroscopy and show the NMR-derived distances to be remarkably consistent with distances derived from Pulsed Electron–Electron Dipolar Resonance.German Science Foundation (collaborative research centers 807 and 902)National Science Foundation (U.S.) (Grant MCB 0744415

    Efficacy of sulphadoxine-pyrimethamine with or without artesunate for the treatment of uncomplicated Plasmodium falciparum malaria in southern Mozambique: a randomized controlled trial

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    BACKGROUND: An artemisinin-based combination therapy, artesunate (AS) plus sulphadoxine-pyrimethamine (SP), was compared to SP monotherapy to provide evidence of further treatment options in southern Mozambique. METHODS: Between 2003 and 2005, 411 patients over one year and 10 kg with uncomplicated Plasmodium falciparum malaria were randomly allocated SP (25/1.25 mg per kg day 0) or AS/SP (as above plus 4 mg/kg artesunate days 0, 1 and 2). Allocation was concealed, but treatment was open-label except to microscopists. The primary objective was the relative risk of treatment failure, which was assessed using World Health Organization response definitions modified to a 42-day follow-up. RESULTS: Of the 411 subjects enrolled, 359 (87.3%) completed the follow up period (SP n = 175, AS/SP n = 184). A survival analysis including 408 subjects showed that the polymerase chain reaction-adjusted cure rates were 90.4% (95% confidence interval [CI] 84.9%-93.9%) and 98.0% (95% CI 94.8%-99.3%) for SP and AS/SP respectively. Multivariable analysis showed that treatment with AS/SP decreased the relative hazard of treatment failure by 80% compared to SP (hazard ratio [HR] 0.2; 95% CI 0.1-0.6) and age over seven years decreased the relative hazard of failure by 70% (HR 0.3; 95% CI 0.1-0.9), when compared to younger age. However, having a quintuple dhfr/dhps mutation increased the relative hazard of failure compared to fewer mutations (HR 3.2; 95% CI 1.3-7.5) and baseline axillary temperature increased the relative hazard of failure by 50% for each degreesC increase (HR 1.5; 95% CI 1.1-2.2). CONCLUSION: While both treatments were efficacious, AS plus SP significantly decreased the relative hazard of treatment failure compared to SP monotherapy Artesunate plus sulphadoxine-pyrimethamine, but not sulphadoxine-pyrimethamine monotherapy, met the current WHO criteria of >95% efficacy for policy implementation.TRIAL REGISTRATION:NCT00203736 and NCT0020381

    Narratives of Black Women STEM Faculty: Breaking Barriers to Promote Institutional Transformation at Historically Black Colleges and Universities

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    Women faculty at Historically Black Colleges and Universities (HBCUs), experience many barriers. HBCUs’ rich histories of advancing racial equity have often outweighed a focus on gender equity, with issues at the intersection of race and gender receiving minimal attention. This study highlights the need for institutional transformation at HBCUs by identifying the structural factors that promote and inhibit Black women STEM faculty advancement. Interviews (n=15) were conducted with HBCU Black women STEM faculty using the Life Interview approach. The three major themes related to barriers included: (a) greater likelihood of having their expertise questioned, (b) increased pressure to work harder, and (c) sexism, racism, and gendered racism. This study expands upon existing research in the literature by focusing on an understudied population, Black women STEM faculty at HBCUs. Findings suggest that to advance institutional transformation diversity, equity, and inclusion goals, colleges and universities must establish infrastructures that include supports of benefit to the professional advancement of all faculty

    Assigning the EPR fine structure parameters of the Mn(II) centers in bacillus subtilis oxalate decarboxylase by site-directed mutagenesis and DFT/MM calculations

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    Oxalate decarboxylase (OxDC) catalyzes the Mn-dependent conversion of the oxalate monoanion into CO2 and formate. EPR-based strategies for investigating the catalytic mechanism of decarboxylation are complicated by the difficulty of assigning the signals associated with the two Mn(II) centers located in the N- and C-terminal cupin domains of the enzyme. We now report a mutational strategy that has established the assignment of EPR fine structure parameters to each of these Mn(II) centers at pH 8.5. These experimental findings are also used to assess the performance of a multistep strategy for calculating the zero-field splitting parameters of protein-bound Mn(II) ions. Despite the known sensitivity of calculated D and E values to the computational approach, we demonstrate that good estimates of these parameters can be obtained using cluster models taken from carefully optimized DFT/MM structures. Overall, our results provide new insights into the strengths and limitations of theoretical methods for understanding electronic properties of protein-bound Mn(II) ions, thereby setting the stage for future EPR studies on the electronic properties of the Mn(II) centers in OxDC and site-specific variants

    Integrating social nutrition principles into the treatment of steatotic liver disease

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    Current treatment of metabolic dysfunction-associated steatotic liver disease (MASLD) focuses on adjusting patients’ lifestyles, including promoting weight loss and physical activity. Here, we suggest adopting a holistic preventive hepatology approach encompassing social nutrition, social prescribing and broader societal changes to facilitate individuals’ engagement with behavioural modifications

    Eliciting adverse effects data from participants in clinical trials.

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    BACKGROUND: Analysis of drug safety in clinical trials involves assessing adverse events (AEs) individually or by aggregate statistical synthesis to provide evidence of likely adverse drug reactions (ADR). While some AEs may be ascertained from physical examinations or tests, there is great reliance on reports from participants to detect subjective symptoms, where he/she is often the only source of information. There is no consensus on how these reports should be elicited, although it is known that questioning methods influence the extent and nature of data detected. This leaves room for measurement error and undermines comparisons between studies and pooled analyses. This review investigated comparisons of methods used in trials to elicit participant-reported AEs. This should contribute to knowledge about the methodological challenges and possible solutions for achieving better, or more consistent, AE ascertainment in trials. OBJECTIVES: To systematically review the research that has compared methods used within clinical drug trials (or methods that would be specific for such trials) to elicit information about AEs defined in the protocol or in the planning for the trial. SEARCH METHODS: Databases (searched to March 2015 unless indicated otherwise) included: Embase; MEDLINE; MEDLINE in Process and Other Non-Indexed Citations; Cochrane Methodology Register (July 2012); Cochrane Central Register of Controlled Trials (February 2015); Cochrane Database of Systematic Reviews; Database of Abstracts of Reviews of Effects (January 2015); Health Technology Assessment database (January 2015); CINAHL; CAB Abstracts; BIOSIS (July 2013); Science Citation Index; Social Science Citation Index; Conference Proceedings Citation Index - Science. The search used thesaurus headings and synonyms for the following concepts: (A): Adverse events AND measurement; (B): Participants AND elicitation (also other synonyms for extraction of information about adverse effects from people); (C): Participants AND checklists (also other synonyms as for B). Pragmatic ways were used to limit the results whilst trying to maintain sensitivity. There were no date or sample size restrictions but only reports published in English were included fully, because of resource constraints as regards translation. SELECTION CRITERIA: Two types of studies were included: drug trials comparing two or more methods within- or between-participants to elicit participant-reported AEs, and research studies performed outside the context of a trial to compare methods which could be used in trials (evidenced by reference to such applicability). Primary outcome data included AEs elicited from participants taking part in any such clinical trial. We included any participant-reported data relevant for an assessment of drug-related harm, using the original authors' terminology (and definition, where available), with comment on whether the data were likely to be treatment-emergent AEs or not. DATA COLLECTION AND ANALYSIS: Titles and abstracts were independently reviewed for eligibility. Full texts of potentially eligible citations were independently reviewed for final eligibility. Relevant data were extracted and subjected to a 100% check. Disagreements were resolved by discussion, involving a third author. The risk of bias was independently assessed by two authors. The Cochrane 'Risk of bias' tool was used for reports comparing outcomes between participants, while for within-participant comparisons, each study was critically evaluated in terms of potential impact of the design and conduct on findings using the framework of selection, performance, detection, attrition, reporting, and other biases. An attempt was made to contact authors to retrieve protocols or specific relevant missing information. Reports were not excluded on the basis of quality unless data for outcomes were impossible to compare (e.g. where denominators differed). A narrative synthesis was conducted because differences in study design and presentation meant that a quantitative meta-analysis was not possible. MAIN RESULTS: The 33 eligible studies largely compared open questions with checklist-type questions or rating scales. Two included participant interviews. Despite different designs, populations and details of questioning methods, the narrative review showed that more specific questioning of participants led to more AEs detected compared to a more general enquiry. A subset of six studies suggested that more severe, bothersome, or otherwise clinically relevant AEs were reported when an initial open enquiry was used, while some less severe, bothersome, or clinically relevant AEs were only reported with a subsequent specific enquiry. However, two studies showed that quite severe or debilitating AEs were only detected by an interview, while other studies did not find a difference in the nature of AEs between elicitation methods. No conclusions could be made regarding the impact of question method on the ability to detect a statistically significant difference between study groups. There was no common statistical rubric, but we were able to represent some effect measures as a risk ratio of the proportion of participants with at least one AE. This showed a lower level of reporting for open questions (O) compared to checklists (CL), with a range for the risk ratios of 0.12 to 0.64. AUTHORS' CONCLUSIONS: This review supports concerns that methods to elicit participant-reported AEs influence the detection of these data. There was a risk for under-detection of AEs in studies using a more general elicitation method compared to those using a comprehensive method. These AEs may be important from a clinical perspective or for patients. This under-detection could compromise ability to pool AE data. However, the impact on the nature of the AE detected by different methods is unclear. The wide variety and low quality of methods to compare elicitation strategies limited this review. Future studies would be improved by using and reporting clear definitions and terminology for AEs (and other important variables), frequency and time period over which they were ascertained, how they were graded, assessed for a relationship to the study drug, coded, and tabulated/reported. While the many potential AE endpoints in a trial may preclude the development of general AE patient-reported outcome measurement instruments, much could also be learnt from how these employ both quantitative and qualitative methods to better understand data elicited. Any chosen questioning method needs to be feasible for use by both staff and participants

    Reticular formation responses to magnetic brain stimulation of primary motor cortex

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    Transcranial magnetic stimulation (TMS) of cerebral cortex is a popular technique for the non-invasive investigation of motor function. TMS is often assumed to influence spinal circuits solely via the corticospinal tract. We were interested in possible trans-synaptic effects of cortical TMS on the ponto-medullary reticular formation in the brainstem, which is the source of the reticulospinal tract and could also generate spinal motor output. We recorded from 210 single units in the reticular formation of three anaesthetized macaque monkeys whilst TMS was performed over primary motor cortex. Short latency responses were observed consistent with activation of a cortico-reticular pathway. However, we also demonstrated surprisingly powerful responses at longer latency, which often appeared at lower threshold than the earlier effects. These late responses seemed to be generated partly as a consequence of the sound click made by coil discharge, and changed little with coil location. This novel finding has implications for the design of future studies using TMS, as well as suggesting a means of non-invasively probing an otherwise inaccessible important motor centre
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