381 research outputs found

    Application of ER Stress Biomarkers to Predict Formulated Monoclonal Antibody Stability

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    For a therapeutic mAb to reach the clinic, the molecule must be produced at an appropriate yield and quality, then formulated to maintain efficacy and stability. The formation of sub‐visible particles (SVPs) can impact on product stability and is monitored during formulation development however, the potential of a mAb to form such species can be influenced throughout the whole bioprocess. We investigate levels of intracellular ER stress perceived by cells, day of mAb harvest and the relationship to subsequent product stability of two mAbs (denoted A and B), produced in CHO cell lines, as determined by SVP content after accelerated stability studies. We show the propensity of mAb A to form SVPs can be predicted by transcript expression of biomarkers of cellular ER stress, heavy/light chain transcript and polypeptide amounts, and harvest day. Further, mAb A material harvested on day 9 of culture was more stable, in terms of SVP formation, than material harvested on day 13. These data suggest that ER stress perceived by CHO cells during culture can reflect the stability of a mAb, and that biomarkers of such stress could help define culture harvest time as a tool to control or reduce SVP formation in formulated mAbs

    RNA interference of endochitinases in the sugarcane endophyte Trichoderma virens 223 reduces its fitness as a biocontrol agent of pineapple disease

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    publication-status: PublishedThe sugarcane root endophyte Trichoderma virens 223 holds enormous potential as a sustainable alternative to chemical pesticides in the control of sugarcane diseases. Its efficacy as a biocontrol agent is thought to be associated with its production of chitinase enzymes, including N-acetyl-β-D-glucosaminidases, chitobiosidases and endochitinases. We used targeted gene deletion and RNA-dependent gene silencing strategies to disrupt N-acetyl-β-D-glucosaminidase and endochitinase activities of the fungus, and to determine their roles in the biocontrol of soil-borne plant pathogens. The loss of N-acetyl-β-D-glucosaminidase activities was dispensable for biocontrol of the plurivorous damping-off pathogens Rhizoctonia solani and Sclerotinia sclerotiorum, and of the sugarcane pathogen Ceratocystis paradoxa, the causal agent of pineapple disease. Similarly, suppression of endochitinase activities had no effect on R. solani and S. sclerotiorum disease control, but had a pronounced effect on the ability of T. virens 223 to control pineapple disease. Our work demonstrates a critical requirement for T. virens 223 endochitinase activity in the biocontrol of C. paradoxa sugarcane disease, but not for general antagonism of other soil pathogens. This may reflect its lifestyle as a sugarcane root endophyte

    Carotid artery wall mechanics in young males with high cardiorespiratory fitness

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    The influence of cardiorespiratory fitness (CRF) on arterial stiffness in young adults remains equivocal. Beyond conventional measures of arterial stiffness, 2D strain imaging of the common carotid artery (CCA) provides novel information related to the intrinsic properties of the arterial wall. Therefore, this study aimed to assess the effect of CRF on both conventional indices of CCA stiffness and 2D strain parameters, at rest and following a bout of aerobic exercise in young healthy males. Short‐axis ultrasound images of the CCA were recorded in 34 healthy men [22 years (95%CI, 19–22)] before, and immediately after 5‐minutes of aerobic exercise (40% VO2max). Images were analysed for arterial diameter, peak circumferential strain (PCS), and peak systolic and diastolic strain rates (S‐SR, D‐SR). Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) were simultaneously assessed and Petersons' elastic modulus (Ep) and Beta stiffness (β1) were calculated. Participants were separated post hoc into moderate and high fitness groups [VO2max: 48.9 ml.kg‐1 min‐1 (95%CI, 44.7–53.2) vs. 65.6 ml.kg‐1 min‐1 (95%CI, 63.1–68.1); P 0.13) but were elevated in the moderate‐fitness group post‐exercise (P 0.05). High‐fit individuals exhibit elevated CCA PCS and S‐SR, which may reflect training‐induced adaptations that help to buffer the rise in pulse‐pressure and stroke volume during exercise

    Aortic haemodynamics: the effects of habitual endurance exercise, age and muscle sympathetic vasomotor outflow in healthy men

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    PURPOSE: We determined the effect of habitual endurance exercise and age on aortic pulse wave velocity (aPWV), augmentation pressure (AP) and systolic blood pressure (aSBP), with statistical adjustments of aPWV and AP for heart rate and aortic mean arterial pressure, when appropriate. Furthermore, we assessed whether muscle sympathetic nerve activity (MSNA) correlates with AP in young and middle-aged men. METHODS: Aortic PWV, AP, aortic blood pressure (applanation tonometry; SphygmoCor) and MSNA (peroneal microneurography) were recorded in 46 normotensive men who were either young or middle-aged and endurance-trained runners or recreationally active nonrunners (10 nonrunners and 13 runners within each age-group). Between-group differences and relationships between variables were assessed via ANOVA/ANCOVA and Pearson product-moment correlation coefficients, respectively. RESULTS: Adjusted aPWV and adjusted AP were similar between runners and nonrunners in both age groups (all, P > 0.05), but higher with age (all, P < 0.001), with a greater effect size for the age-related difference in AP in runners (Hedges’ g, 3.6 vs 2.6). aSBP was lower in young (P = 0.009; g = 2.6), but not middle-aged (P = 0.341; g = 1.1), runners compared to nonrunners. MSNA burst frequency did not correlate with AP in either age group (young: r = 0.00, P = 0.994; middle-aged: r = − 0.11, P = 0.604). CONCLUSION: There is an age-dependent effect of habitual exercise on aortic haemodynamics, with lower aSBP in young runners compared to nonrunners only. Statistical adjustment of aPWV and AP markedly influenced the outcomes of this study, highlighting the importance of performing these analyses. Further, peripheral sympathetic vasomotor outflow and AP were not correlated in young or middle-aged normotensive men

    Personalized rTMS for Depression: A Review

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    Personalized treatments are gaining momentum across all fields of medicine. Precision medicine can be applied to neuromodulatory techniques, where focused brain stimulation treatments such as repetitive transcranial magnetic stimulation (rTMS) are used to modulate brain circuits and alleviate clinical symptoms. rTMS is well-tolerated and clinically effective for treatment-resistant depression (TRD) and other neuropsychiatric disorders. However, despite its wide stimulation parameter space (location, angle, pattern, frequency, and intensity can be adjusted), rTMS is currently applied in a one-size-fits-all manner, potentially contributing to its suboptimal clinical response (~50%). In this review, we examine components of rTMS that can be optimized to account for inter-individual variability in neural function and anatomy. We discuss current treatment options for TRD, the neural mechanisms thought to underlie treatment, differences in FDA-cleared devices, targeting strategies, stimulation parameter selection, and adaptive closed-loop rTMS to improve treatment outcomes. We suggest that better understanding of the wide and modifiable parameter space of rTMS will greatly improve clinical outcome

    Aberration-like cusped focusing in the post-paraxial Talbot effect

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    We present an analysis of self-imaging in a regime beyond the paraxial, where deviation from simple paraxial propagation causes apparent self-imaging aberrations. The resulting structures are examples of aberration without rays and are described analytically using post-paraxial theory. They are shown to relate to, but surprisingly do not precisely replicate, a standard integral representation of a diffraction cusp. Beyond the Talbot effect, this result is significant as it illustrates that the effect of aberration -- as manifested in the replacement of a perfect focus with a cusp-like pattern -- can occur as a consequence of improving the paraxial approximation, rather than due to imperfections in the optical system.Comment: 8 pages, 3 figures, IoP styl

    Decision-making and referral processes for patients with motor neurone disease: a qualitative study of GP experiences and evaluation of a new decision-support tool

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    Background The diagnosis of motor neurone disease (MND) is known to be challenging and there may be delay in patients receiving a correct diagnosis. This study investigated the referral process for patients who had been diagnosed with MND, and whether a newly-developed tool (The Red Flags checklist) might help General Practitioners (GPs) in making referral decisions. Methods We carried out interviews with GPs who had recently referred a patient diagnosed with MND, and interviews/surveys with GPs who had not recently referred a patient with suspected MND. We collected data before the Red Flags checklist was introduced; and again one year later. We analysed the data to identify key recurring themes. Results Forty two GPs took part in the study. The presence of fasciculation was the clinical feature that most commonly led to consideration of a potential MND diagnosis. GPs perceived that their role was to make onward referrals rather than attempting to make a diagnosis, and delays in correct diagnosis tended to occur at the specialist level. A quarter of participants had some awareness of the newly-developed tool; most considered it useful, if incorporated into existing systems. Conclusions While fasciculation is the most common symptom associated with MND, other bulbar, limb or respiratory features, together with progression should be considered. There is a need for further research into how decision-support tools should be designed and provided, in order to best assist GPs with referral decisions. There is also a need for further work at the level of secondary care, in order that referrals made are re-directed appropriately

    A description of the origins, design and performance of the TRAITS-SGP Atlantic salmon Salmo salar L. cDNA microarray

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    The origins, design, fabrication and performance of an Atlantic salmon microarray are described. The microarray comprises 16 950 Atlantic salmon-derived cDNA features, printed in duplicate and mostly sourced from pre-existing expressed sequence tag (EST) collections [SALGENE and salmon genome project (SGP)] but also supplemented with cDNAs from suppression subtractive hybridization libraries and candidate genes involved in immune response, protein catabolism, lipid metabolism and the parr–smolt transformation. A preliminary analysis of a dietary lipid experiment identified a number of genes known to be involved in lipid metabolism. Significant fold change differences (as low as 1.2x) were apparent from the microarray analysis and were confirmed by quantitative real-time polymerase chain reaction analysis. The study also highlighted the potential for obtaining artefactual expression patterns as a result of cross-hybridization of similar transcripts. Examination of the robustness and sensitivity of the experimental design employed demonstrated the greater importance of biological replication over technical (dye flip) replication for identification of a limited number of key genes in the studied system. The TRAITS (TRanscriptome Analysis of Important Traits of Salmon)–salmon genome project microarray has been proven, in a number of studies, to be a powerful tool for the study of key traits of Atlantic salmon biology. It is now available for use by researchers in the wider scientific community

    MeCP2 Regulates the Synaptic Expression of a Dysbindin-BLOC-1 Network Component in Mouse Brain and Human Induced Pluripotent Stem Cell-Derived Neurons

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    Clinical, epidemiological, and genetic evidence suggest overlapping pathogenic mechanisms between autism spectrum disorder (ASD) and schizophrenia. We tested this hypothesis by asking if mutations in the ASD gene MECP2 which cause Rett syndrome affect the expression of genes encoding the schizophrenia risk factor dysbindin, a subunit of the biogenesis of lysosome-related organelles complex-1 (BLOC-1), and associated interacting proteins. We measured mRNA and protein levels of key components of a dysbindin interaction network by, quantitative real time PCR and quantitative immunohistochemistry in hippocampal samples of wild-type and Mecp2 mutant mice. In addition, we confirmed results by performing immunohistochemistry of normal human hippocampus and quantitative qRT-PCR of human inducible pluripotent stem cells (iPSCs)-derived human neurons from Rett syndrome patients. We defined the distribution of the BLOC-1 subunit pallidin in human and mouse hippocampus and contrasted this distribution with that of symptomatic Mecp2 mutant mice. Neurons from mutant mice and Rett syndrome patients displayed selectively reduced levels of pallidin transcript. Pallidin immunoreactivity decreased in the hippocampus of symptomatic Mecp2 mutant mice, a feature most prominent at asymmetric synapses as determined by immunoelectron microcopy. Pallidin immunoreactivity decreased concomitantly with reduced BDNF content in the hippocampus of Mecp2 mice. Similarly, BDNF content was reduced in the hippocampus of BLOC-1 deficient mice suggesting that genetic defects in BLOC-1 are upstream of the BDNF phenotype in Mecp2 deficient mice. Our results demonstrate that the ASD-related gene Mecp2 regulates the expression of components belonging to the dysbindin interactome and these molecular differences may contribute to synaptic phenotypes that characterize Mecp2 deficiencies and ASD.Fil: Larimore, Jennifer. Agnes Scott College; Estados UnidosFil: Ryder, Pearl V.. University of Emory; Estados UnidosFil: Kim, Kun Yong. University of Yale. School of Medicine; Estados UnidosFil: Ambrose, L. Alex. Agnes Scott College; Estados UnidosFil: Chapleau, Christopher. University Of Alabama; Estados UnidosFil: Calfa, Gaston Diego. University Of Alabama; Estados Unidos. Consejo Nacional de Investigaciones CientĂ­ficas y TĂŠcnicas; ArgentinaFil: Gross, Christina. University of Emory; Estados UnidosFil: Bassell, Gary J.. University of Emory; Estados UnidosFil: Pozzo Miller, Lucas. University Of Alabama; Estados UnidosFil: Smith, Yoland. University of Emory; Estados UnidosFil: Talbot, Konrad. The Pennsylvania State University; Estados UnidosFil: Park, In Hyun. University of Yale. School of Medicine; Estados UnidosFil: Faundez, Victor. University of Emory; Estados Unido

    The influence of habitual endurance exercise on carotid artery strain and strain-rate in young and middle-aged men

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    Central arterial stiffness is an independent predictor of cardiovascular risk that can be modified by exercise training. However, conventional local measures of carotid artery stiffness display conflicting responses to habitual endurance exercise in young and older adults. 2D-Strain imaging of the common carotid artery (CCA) quantifies circumferential deformation (strain) of the arterial wall across the cardiac cycle, which is more sensitive at detecting age-related alterations in CCA stiffness than conventional methods. Therefore, the study was designed to examine the relationship between habitual endurance exercise (running) and CCA 2D-Strain parameters in young and middle-aged men. Short-axis ultrasound images of the CCA were obtained from 13 young nonrunners (23 years [95% CI: 21-26]), 19 young runners (24 [22-26]), 13 middle-aged nonrunners (54 [52-56]) and 19 middle-aged runners (56 [54-58]). Images were analysed for peak circumferential strain (PCS; magnitude of deformation) as well as systolic and diastolic strain-rate (S-SR and D-SR; deformation velocity) and group differences were examined via two-way ANOVA. PCS, S-SR and D-SR were attenuated in middle-aged males when compared to young men (all P ≤ 0.001). PCS and S-SR were elevated in young and middle-aged runners when compared to nonrunners (P = 0.002 and P =0.009 respectively), but no age*training status interaction was observed. In contrast, there was no influence of habitual running on D-SR. Habitual exercise is associated with comparable improvements in CCA 2D-Strain parameters in young and middle-aged men, but the age-related decline in PCS and S-SR may be more amenable to habitual endurance exercise than D-SR
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