111 research outputs found
Sodium bicarbonate buffered diets for marketing and transportation stressed feeder steers
Fifty-four weanling steer calves were sxibjected to one of three pre-shipment treatments: (1) normal industry stresses (Normal Industry); (2) fed a high-energy, high-antibiotic diet in the order-buyer barn (High Energy) ; or (3) preweaned and fed a concentrate diet for 30 days before marketing (Preweaned). After being exposed to commercial auction and order-buyer barn environments for 4 days, the steers were assigned to one of three post-shipment treatments: (1) nonbuffered control (Nonbuffered); (2) 40 grams of sodium bicarbonate per steer per day (40- gram-NaHCO3); and (3) 80 grams of sodium bicarbonate per steer per day (BO-gram-NaHCO3) in a 3X3 factorial arrangement with pre-shipment treatments.
Ruminal pH and in vitro gas production values decreased as the steers progressed through the normal sequence of market-transit events (auction barn, order-buyer barn and trucking) and were significantly lower upon arrival at the feedlot than at the farm of origin or upon arrival at the auction barn. Pre-shipment concentrate feeding at the farm of origin or in the order-buyer barn significantly reduced ruminal pH and increased in vitro gas production. In steers subjected to normal industry market-transit stresses, increased gas production was observed in the 40- and 80-gram NaHCO3-supplemented groups on feedlot sampling day 4, 11 and 32. However, in calves preweaned and fed a concentrate diet at the farm of origin or order-buyer barn no response to feedlot NaHCO^ supplementation was observed until feedlot day 32 and these responses were inconsistent and of lower magnitude than in the normal-industry-stressed steers. Packed cell volume, total serum protein, red blood cell count, white blood cell count and rumen protozoa concentration were not affected by feedlot sodium bicarbonate supplementation.
There was a significant pre- by post-shipment treatment interaction with respect to feedlot gain. Feeding 80 grams of NaHCO3 to Normal-Industry stressed steers and feeding 40 grams NaHCO3 to High- Energy steers resulted in higher cumulative ADG to feedlot day 11 than the respective Nonbuffered groups. In Normal-Industry NaHCO3-buffered steers, feedlot time required to regain market-transit shrink was shorter, illness index was lower, and elevated early feedlot rectal temperatures returned to normal values quicker than in Nonbuffered steers. In High-Energy steers the 40 grams NaHCO3 resulted in higher early-feedlot gains but had no effect on rectal temperatures and in Preweaned steers, the Nonbuffered steers gained faster to feedlot day 11 than the other NaHCO3 groups. Although, NaHCO3 increased the rate of feedlot adaptation, its beneficial effects were limited to the early feedlot period when used as a buffering agent with a high corn-silage ration.
Preweaned steers gained more weight at the farm of origin. High- Energy steers lost more weight during the auction-barn, order-buyer barn .phase and Normal Industry steers lost more on the truck than steers in the other two groups, respectively. However, total market-transit weight loss was similar for the three pre-shipment treatments
Efficacy of probucol on cognitive function in Alzheimer's disease: study protocol for a double-blind, placebo-controlled, randomised phase II trial (PIA study).
INTRODUCTION: Preclinical, clinical and epidemiological studies support the hypothesis that aberrant systemic metabolism of amyloid beta (Aβ) in the peripheral circulation is causally related to the development of Alzheimer's disease (AD). Specifically, recent studies suggest that increased plasma concentrations of lipoprotein-Aβ compromise the brain microvasculature, resulting in extravasation and retention of the lipoprotein-Aβ moiety. The latter results in an inflammatory response and neurodegeneration ensues. Probucol, a historic cholesterol-lowering drug, has been shown in murine models to suppress lipoprotein-Aβ secretion, concomitant with maintaining blood-brain-barrier function, suppressing neurovascular inflammation and supporting cognitive function. This protocol details the probucol in Alzheimer's study, a drug intervention trial investigating if probucol has potential to attenuate cognitive decline, delay brain atrophy and reduce cerebral amyloid burden in patients with mild-to-moderate AD.
METHODS AND ANALYSIS: The study is a phase II, randomised, placebo-controlled, double-blind single-site clinical trial held in Perth, Australia. The target sample is 314 participants with mild-to-moderate AD. Participants will be recruited and randomised (1:1) to a 104-week intervention consisting of placebo induction for 2 weeks followed by 102 weeks of probucol (Lorelco) or placebo. The primary outcome is changed in cognitive performance determined via the Alzheimer's Disease Assessment Scales-Cognitive Subscale test between baseline and 104 weeks. Secondary outcomes measures will be the change in brain structure and function, cerebral amyloid load, quality of life, and the safety and tolerability of Lorelco, after a 104week intervention.
ETHICS AND DISSEMINATION: The study has been approved by the Bellberry Limited Human Research Ethics Committee (approval number: HREC2019-11-1063; Version 4, 6 October 2021). Informed consent will be obtained from participants prior to any study procedures being performed. The investigator group will disseminate study findings through peer-reviewed publications, key conferences and local stakeholder events.
TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN12621000726853)
Treatment of the fixation surface improves glenoid prosthesis longevity in-vitro
Many commercial cemented glenoid components claim superior fixation designs and increased survivability. However, both research and clinical studies have shown conflicting results and it is unclear whether these design variations do improve loosening rates. Part of the difficulty in investigating fixation failure is the inability to directly observe the fixation interface, a problem addressed in this study by using a novel experimental set-up.Cyclic loading-displacement tests were carried out on 60 custom-made glenoid prostheses implanted into a bone substitute. Design parameters investigated included treatment of the fixation surface of the component resulting in different levels of back-surface roughness, flat-back versus curved-back, keel versus peg and more versus less conforming implants. Visually-observed failure and ASTM-recommended rim-displacements were recorded throughout testing to investigate fixation failure and if rim displacement is an appropriate measure of loosening. Roughening the implant back (Ra > 3 µm) improved resistance to failure (P < 0.005) by an order of magnitude with the rough and smooth groups failing at 8712 ± 5584 cycles (mean ± SD) and 1080 ± 1197 cycles, respectively. All other design parameters had no statistically significant effect on the number of cycles to failure. All implants failed inferiorly and 95 % (57/60) at the implant/cement interface. Rim-displacement correlated with visually observed failure. The most important effect was that of roughening the implant, which strengthened the polyethylene-cement interface. Rim-displacement can be used as an indicator of fixation failure, but the sensitivity was insufficient to capture subtle effects.Level of Evidence: Basic Science Study, Biomechanical Analysis
Discovery of an orally active benzoxaborole prodrug effective in the treatment of Chagas disease in non-human primates
Trypanosoma cruzi, the agent of Chagas disease, probably infects tens of millions of people, primarily in Latin America, causing morbidity and mortality. The options for treatment and prevention of Chagas disease are limited and underutilized. Here we describe the discovery of a series of benzoxaborole compounds with nanomolar activity against extra- and intracellular stages of T. cruzi. Leveraging both ongoing drug discovery efforts in related kinetoplastids, and the exceptional models for rapid drug screening and optimization in T. cruzi, we have identified the prodrug AN15368 that is activated by parasite carboxypeptidases to yield a compound that targets the messenger RNA processing pathway in T. cruzi. AN15368 was found to be active in vitro and in vivo against a range of genetically distinct T. cruzi lineages and was uniformly curative in non-human primates (NHPs) with long-term naturally acquired infections. Treatment in NHPs also revealed no detectable acute toxicity or long-term health or reproductive impact. Thus, AN15368 is an extensively validated and apparently safe, clinically ready candidate with promising potential for prevention and treatment of Chagas disease
Standardised Data on Initiatives – STARDIT: Beta Version
There is currently no standardised way to share information across disciplines about
initiatives, including felds such as health, environment, basic science, manufacturing, media and international
development. All problems, including complex global problems such as air pollution and pandemics require reliable
data sharing between disciplines in order to respond efectively. Current reporting methods also lack information
about the ways in which diferent people and organisations are involved in initiatives, making it difcult to collate
and appraise data about the most efective ways to involve diferent people. The objective of STARDIT (Standardised
Data on Initiatives) is to address current limitations and inconsistencies in sharing data about initiatives. The STARDIT
system features standardised data reporting about initiatives, including who has been involved, what tasks they did,
and any impacts observed. STARDIT was created to help everyone in the world fnd and understand information
about collective human actions, which are referred to as ‘initiatives’. STARDIT enables multiple categories of data to be
reported in a standardised way across disciplines, facilitating appraisal of initiatives and aiding synthesis of evidence
for the most effective ways for people to be involved in initiatives
Tetracosahexaenoylethanolamide, a novel -acylethanolamide, is elevated in ischemia and increases neuronal output.
-acylethanolamines (NAEs) are endogenous lipid-signaling molecules derived from fatty acids that regulate numerous biological functions, including in the brain. Interestingly, NAEs are elevated in the absence of fatty acid amide hydrolase (FAAH) and following CO-induced ischemia/hypercapnia, suggesting a neuroprotective response. Tetracosahexaenoic acid (THA) is a product and precursor to DHA; however, the NAE product, tetracosahexaenoylethanolamide (THEA), has never been reported. Presently, THEA was chemically synthesized as an authentic standard to confirm THEA presence in biological tissues. Whole brains were collected and analyzed for unesterified THA, total THA, and THEA in wild-type and FAAH-KO mice that were euthanized by either head-focused microwave fixation, CO + microwave, or CO only. PPAR activity by transient transfection assay and ex vivo neuronal output in medium spiny neurons (MSNs) of the nucleus accumbens by patch clamp electrophysiology were determined following THEA exposure. THEA in the wild-type mice was nearly doubled ( 0.05) transcriptional activity of PPARs relative to control, but 100 nM of THEA increased ( < 0.001) neuronal output in MSNs of the nucleus accumbens. Here were identify a novel NAE, THEA, in the brain that is elevated upon ischemia/hypercapnia and by KO of the FAAH enzyme. While THEA did not activate PPAR, it augmented the excitability of MSNs in the nucleus accumbens. Overall, our results suggest that THEA is a novel NAE that is produced in the brain upon ischemia/hypercapnia and regulates neuronal excitation
Recommended from our members
Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
- …