9,887 research outputs found
Expression of a tick toxin for the development of a canine vaccine
University of Technology, Sydney. Faculty of Science.Acute, ascending, flaccid motor paralysis of forelimbs and death due to respiratory failure is the dominant characteristic of tick toxicosis by the Australian paralysis tick, Ixodes holocyclus. A tick toxin vaccine has the potential to be an effective preventative measure against tick toxicosis that affects thousands of domestic and companion animals each year. In previous research for the development of an anti-tick vaccine, Masina (1999) used a maltose-binding protein (MBP) holocyclus toxin (HT-1) fusion protein as immunogen. It was partially protective against challenges with crude tick extract in neonatal mice but unable to protect dogs against paralysis caused by direct tick attachment.
Subsequently, four monoclonal antibodies generated in this study against the fusion protein were found to be incapable of binding to the native toxin in crude tick extract in Western blots. These results indicated that the HT-1 component of the MBP fusion protein was incorrectly folded compared to the native toxin.
An expression system using ubiquitin fusion protein was investigated. Ubiquitin is a 10 kDa carrier protein which is smaller than the 43 kDa MBP. A smaller fusion partner was considered as it is less likely to interfere with HT-1 folding. The ubiquitin-HT-1 fusion protein was expressed in both soluble and insoluble forms, corresponding to the cytoplasmic fraction and inclusion bodies. The soluble form could be purified under non-denaturing conditions utilising the incorporated His-6-tag and a Ni affinity column. The insoluble form, like the periplasmically expressed MBP-HT-1 fusion protein, could only be purified using denaturing conditions.
The purified soluble ubiquitin-HT-1 fusion protein appeared to have the correct conformational folding as it was recognized by commercial dog anti-tick serum in Western blots. The purified soluble ubiquitin-HT-1 fusion protein was used to immunise rabbits and mice for protection experiments, but was found to be unprotective. However, serum from immunized animals was able to detect a 5 kDa protein from crude tick extract in a Western blot. This 5 kDa protein was also recognized by the commercial dog anti-tick serum and has the molecular weight corresponding to the HT-1 neurotoxin. Creation of monoclonal antibodies to this ubiquitin-HT-1 fusion protein may therefore aid future development towards a tick vaccine. These antibodies could in turn be used to isolate native HT-1 from the crude tick extract instead of a combination of conventional chromatography methods. This approach would allow isolation of HT-1 in more significant quantities than is currently possible to enable confirmation of the HT-1 sequence. Suspected problems associated with incorrect sequence or interference by the carrier protein to cause a non-protective response could also be resolved
Hyperoxia Elevates Adrenic Acid Peroxidation in Marine Fish and Is Associated with Reproductive Pheromone Mediators
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Common Genetic Variant Association with Altered HLA Expression, Synergy with Pyrethroid Exposure, and Risk for Parkinson's Disease: An Observational and Case-Control Study.
Background/objectivesThe common non-coding single nucleotide polymorphism (SNP) rs3129882 in HLA-DRA is associated with risk for idiopathic Parkinson's disease (PD). The location of the SNP in the major histocompatibility complex class II (MHC-II) locus implicates regulation of antigen presentation as a potential mechanism by which immune responses link genetic susceptibility to environmental factors in conferring lifetime risk for PD.MethodsFor immunophenotyping, blood cells from 81 subjects were analyzed by qRT-PCR and flow cytometry. A case-control study was performed on a separate cohort of 962 subjects to determine association of pesticide exposure and the SNP with risk of PD.ResultsHomozygosity for G at this SNP was associated with heightened baseline expression and inducibility of MHC class II molecules in B cells and monocytes from peripheral blood of healthy controls and PD patients. In addition, exposure to a commonly used class of insecticide, pyrethroids, synergized with the risk conferred by this SNP (OR = 2.48, p = 0.007), thereby identifying a novel gene-environment interaction that promotes risk for PD via alterations in immune responses.ConclusionsIn sum, these novel findings suggest that the MHC-II locus may increase susceptibility to PD through presentation of pathogenic, immunodominant antigens and/or a shift toward a more pro-inflammatory CD4+ T cell response in response to specific environmental exposures, such as pyrethroid exposure through genetic or epigenetic mechanisms that modulate MHC-II gene expression
Anthracyclines and Biomarkers of Myocardial Injury: The Effect of Remote Ischemic Conditioning
Background: Remote ischemic conditioning (RIC) has been beneficial in laboratory studies of anthracycline cardiotoxicity, but its effects in patients is not established. Objectives: The authors studied the effect of RIC on cardiac biomarkers and function during and after anthracycline chemotherapy. Methods: The ERIC-Onc study (Effect of Remote Ischaemic Conditioning in Oncology Patients; NCT02471885) was a randomized, single-blind, sham-controlled study of RIC at each chemotherapy cycle. The primary endpoint was troponin T (TnT) during chemotherapy and up to 1 year. Secondary outcomes included cardiac function, major adverse cardiovascular events (MACE), and MACE or cancer death. Cardiac myosin-binding-protein C (cMyC) was investigated in parallel with TnT. Results: The study was prematurely halted after the evaluation of 55 patients (RIC n = 28, sham n = 27). Biomarkers increased from baseline to cycle 6 of chemotherapy for all patients (median TnT 6 [IQR: 4-9] ng/L to 33 [IQR: 16-36)] ng/L; P ≤ 0.001; cMyC 3 (IQR: 2-5) ng/L to 47 (IQR: 18-49) ng/L; P ≤ 0.001). Mixed-effects regression analysis for repeated measures showed no difference in TnT between the 2 groups (RIC vs sham, mean difference 3.15 ng/L; 95% CI: −0.04 to 6.33; P = 0.053), or cMyC (RIC vs sham, mean difference 4.17 ng/L; 95% CI: −0.12 to 8.45; P = 0.056). There were more MACE and cancer deaths in the RIC group (11 vs 3; HR: 0.25; 95% CI: 0.07-0.90; P = 0.034), with more cancer deaths (8 vs 1; HR: 0.21; 95% CI: 0.04-0.95; P = 0.043) at 1 year. Conclusions: TnT and cMyC significantly increased during anthracycline chemotherapy with 81% having a TnT ≥14 ng/L at cycle 6. RIC did not affect the rise in biomarkers, but there was a small increase in early cancer deaths, possibly related to the greater proportion of patients with metastatic disease randomized to the RIC group (54%vs 37%). (Effect of Remote Ischaemic Conditioning in Oncology Patients [ERIC-ONC]; NCT02471885
Validity of a tool designed to assess the preventability of potentially preventable hospitalizations for chronic conditions
Background: Potentially preventable hospitalizations (PPH) are defined as unplanned hospital admissions which could potentially have been prevented with the provision of effective, timely outpatient care. To better understand and ultimately reduce rates of PPH, a means of identifying those which are actually preventable is required. The Preventability Assessment Tool (PAT) was designed for use by hospital clinicians to assess the preventability of unplanned admissions for chronic conditions. Objective: The present study examined the ability of the PAT to distinguish between those unplanned admissions which are preventable and those which are not, compared to the assessments of an Expert Panel. Methods: Data were collected between November 2014 and June 2017 at three hospitals in NSW, Australia. Participants were community-dwelling patients with unplanned hospital admissions for congestive heart failure, chronic obstructive pulmonary disease, diabetes complications or angina pectoris. A nurse and a doctor caring for the patient made assessments of the preventability of the admission using the PAT. Expert Panels made assessments of the preventability of each admission based on a comprehensive case report and consensus process. Results: There was little concordance between the hospital doctors and nurses regarding the preventability of admissions, nor between the assessments of the Expert Panel and the hospital nurse or the Expert Panel and the hospital doctor. Conclusions: The PAT demonstrated poor concurrent validity and is not a valid tool for assessing the preventability of unplanned hospital admissions. The use of Expert Panels provides a more rigorous approach to assessing the preventability of such admissions
Chemical ordering in PtNi nanocrystals
We investigated the chemical ordering in PtNi nanocrystals fabricated on sapphire substrate using in-situ synchrotron X-ray scattering. Nanocrystals with composition close to 1:1 were ordered in the tetragonal L1(0) structure at low temperatures. The transition to disordered FCC structure occurred at around 640 degrees C and substantial hysteresis of about 50 K was observed. Nanocrystals of smaller sizes fabricated under the same conditions were Ni rich and ordered into Cu3Au type L1(2) structure. Significantly higher degree of chemical ordering was observed in L1(2) structure than in L1(0) structure. (C) 2016 Elsevier B.V. All rights reserved.1144Ysciescopu
Gene Expression Profiling Identified High-mobility Group AT-hook (HMGA2) as Being Frequently Upregulated in Esophageal Squamous Cell Carcinoma
Background: Esophageal cancer is one of the most deadly malignancies worldwide and esophageal squamous cell carcinoma (ESCC) is the most frequent type. Methods: We identified up-regulated genes from gene expression profiles of HKESC-4 cell line, its parental tumor tissues, non-tumoral esophageal epithelia and lymph nodes with metastatic carcinoma using Human Genome U133 Plus 2.0 microarray. Results: Four genes [High-mobility group AT-hook 2 (HMGA2), paternally expressed 10 (PEG10), SH3 and multiple ankyrin repeat domains 2 (SHANK2) and WNT1 inducible signaling pathway protein 3 (WISP3)] were selected for further validation with real-time quantitative polymerase chain reaction (qPCR) in a panel of ESCC cell lines and clinical specimens. HMGA2 was found to be overexpressed in the panel of ESCC cell lines tested. By using immunohistochemistry, HMGA2 was found to be up-regulated in 70% of ESCC tissues (21 out of 30 cases). Conclusion: This study demonstrates successful use of gene microarray to identify and reveal HMGA2 as a novel and consistently overexpressed gene in ESCC cell lines and clinical samples.published_or_final_versio
A Randomized Controlled Trial to Measure Spillover Effects of a Combined Water, Sanitation, and Handwashing Intervention in Rural Bangladesh.
Water, sanitation, and handwashing interventions may confer spillover effects on intervention recipients' neighbors by interrupting pathogen transmission. We measured geographically local spillovers in the Water Quality, Sanitation, and Handwashing (WASH) Benefits Study, a cluster-randomized trial in rural Bangladesh, by comparing outcomes among neighbors of intervention versus those of control participants. Geographically defined clusters were randomly allocated to a compound-level intervention (i.e., chlorinated drinking water, upgraded sanitation, and handwashing promotion) or control arm. From January 2015 to August 2015, in 180 clusters, we enrolled 1,799 neighboring children who were age matched to trial participants who would have been eligible for the study had they been conceived slightly earlier or later. After 28 months of intervention, we quantified fecal indicator bacteria in toy rinse and drinking water samples and measured soil-transmitted helminth infections and caregiver-reported diarrhea and respiratory illness. Neighbors' characteristics were balanced across arms. Detectable Escherichia coli prevalence in tubewell samples was lower for intervention participants' neighbors than control participants' (prevalence ratio = 0.83; 95% confidence interval: 0.73, 0.95). Fecal indicator bacteria prevalence did not differ between arms for other environmental samples. Prevalence was similar in neighbors of intervention participants versus those of control participants for soil-transmitted helminth infection, diarrhea, and respiratory illness. A compound-level water, sanitation, and handwashing intervention reduced neighbors' tubewell water contamination but did not affect neighboring children's health
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