401 research outputs found

    Pasture Conditions at the Initiation of Grazing to Optimize Forage Productivity: A Progress Report

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    To determine environmental, soil, and sward effects at the initiation of cattle grazing in the spring on seasonal (forage accumulated during the grazing season) and cumulative (seasonal + initial forage mass) forage accumulation (FA), 15 commercial cow-calf producers from southern Iowa were selected by historical initial grazing date. At grazing initiation, twelve .25-m2 samples were hand-clipped from each pasture and sward heights (SH) measured with a falling plane meter (4.8 kg/m2) to determine initial forage mass. At each location, soil temperature and load bearing capacity (LBC) were measured and a soil sample was collected to measure pH and moisture, P, and K concentrations. Cumulative degree-days (base=3.85°C) and precipitation at grazing initiation were calculated from NOAA records. At the beginning of each month, at least three grazing exclosures were placed on each grazed pasture to determine monthly FA. SH in each exclosure was recorded, and a .25-m2 forage sample was hand-clipped proximate to each exclosure. At the end of each month, SH was recorded and .25-m2 hand-clipped forage samples from inside exclosures were obtained. In linear regressions, cumulative and seasonal SH increased with greater soil P (r2=.5049 and .5417), soil K (r2=.4675 and .4397), and initial forage mass (r2=.1984 and .2801). Seasonal SH increased with earlier initial grazing dates (r2=.1996) and less accumulated degree-days (r2=.2364). Cumulative and seasonal FA increased with earlier initial grazing dates (r2=.2106 and .3744), lower soil temperatures (r2=.2617 and.2874), and greater soil P (r2=.3489 and .2598). Cumulative FA increased with greater soil K (r2=.4675). In quadratic regressions, cumulative and seasonal SH were correlated to soil P (r2=.6310 and .5310) and soil K (r2=.5095 and.4401). Cumulative and seasonal FA were correlated to degree days (r2=.3630 and.4013) and initial grazing date (r2=.3425 and .4088). Cumulative FA was correlated to soil P (r2=.3539), and seasonal FA was correlated to soil moisture (r2=.3688)

    Clinical disease activity and acute phase reactant levels are discordant among patients with active rheumatoid arthritis: acute phase reactant levels contribute separately to predicting outcome at one year

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    INTRODUCTION: Clinical trials of new treatments for rheumatoid arthritis (RA) typically require subjects to have an elevated acute phase reactant (APR), in addition to tender and swollen joints. However, despite the elevation of individual components of the Clinical Disease Activity Index (CDAI) (tender and swollen joint counts and patient and physician global assessment), some patients with active RA may have normal erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) levels and thus fail to meet entry criteria for clinical trials. We assessed the relationship between CDAI and APRs in the Consortium of Rheumatology Researchers of North America (CORRONA) registry by comparing baseline characteristics and one-year clinical outcomes of patients with active RA, grouped by baseline APR levels. METHODS: This was an observational study of 9,135 RA patients who had both ESR and CRP drawn and a visit at which CDAI was \u3e 2.8 (not in remission). RESULTS: Of 9,135 patients with active RA, 58% had neither elevated ESR nor CRP; only 16% had both elevated ESR and CRP and 26% had either ESR or CRP elevated. Among the 4,228 patients who had a one-year follow-up visit, both baseline and one-year follow-up modified Health Assessment Questionnaire (mHAQ) and CDAI scores were lowest for patients with active RA but with neither APR elevated; both mHAQ and CDAI scores increased sequentially with the increase in number of elevated APR levels at baseline. Each individual component of the CDAI followed the same trend, both at baseline and at one-year follow-up. The magnitude of improvement in both CDAI and mHAQ scores at one year was associated positively with the number of APRs elevated at baseline. CONCLUSIONS: In a large United States registry of RA patients, APR levels often do not correlate with disease activity as measured by joint counts and global assessments. These data strongly suggest that it is appropriate to obtain both ESR and CRP from RA patients at the initial visit. Requiring an elevation in APR levels as a criterion for inclusion of RA patients in studies of experimental agents may exclude some patients with active disease

    Comparative effectiveness of abatacept versus tocilizumab in rheumatoid arthritis patients with prior TNFi exposure in the US Corrona registry

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    BACKGROUND: We compared the effectiveness of abatacept (ABA) vs tocilizumab (TCA) in tumor necrosis factor inhibitor (TNFi) experienced patients. METHODS: We identified rheumatoid arthritis (RA) patients from a large observational US cohort (1 January 2010-31 May 2014) who had discontinued at least one TNFi and initiated ABA or TCZ in moderate or high disease activity based on the Clinical Disease Activity Index (CDAI) and had no prior exposure to the comparator drug. Using propensity score matching (1:1) stratified by prior TNF use (1 TNFi vs ≥2 TNFis), effectiveness at 6 months after initiation was evaluated. Mean change in CDAI over 6 months following initiation was the primary outcome, with secondary outcomes of achievement of low disease activity/remission (CDAI ≤ 10) and mean change in modified Health Assessment Questionnaire (mHAQ) score. RESULTS: The 264 pairs of propensity score-matched ABA and TCZ initiators were well matched with no substantial differences in the baseline characteristics, defined as standardized differences \u3e0.1 in the stratification. Both treatment groups had similar mean change in CDAI at 6 months (-11.3 in ABA vs -9.9 in TCZ; mean difference -1.27, 95% CI -3.65, 1.11). Similar proportions of both treatment groups achieved low disease activity/remission (adjusted odds ratio for ABA vs TCZ 0.99, 95% CI 0.69, 1.43). Mean change in mHAQ was -0.12 in ABA initiators vs -0.11 in TCZ initiations (mean difference -0.01, 95% CI -0.09, 0.06). CONCLUSIONS: Patients receiving either ABA or TCZ had substantial improvement in clinical disease activity. In this propensity score-matched sample, similar outcomes were observed for both treatment cohorts

    A Capsid-Encoded PPxY-Motif Facilitates Adenovirus Entry

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    Viruses use cellular machinery to enter and infect cells. In this study we address the cell entry mechanisms of nonenveloped adenoviruses (Ads). We show that protein VI, an internal capsid protein, is rapidly exposed after cell surface attachment and internalization and remains partially associated with the capsid during intracellular transport. We found that a PPxY motif within protein VI recruits Nedd4 E3 ubiquitin ligases to bind and ubiquitylate protein VI. We further show that this PPxY motif is involved in rapid, microtubule-dependent intracellular movement of protein VI. Ads with a mutated PPxY motif can efficiently escape endosomes but are defective in microtubule-dependent trafficking toward the nucleus. Likewise, depletion of Nedd4 ligases attenuates nuclear accumulation of incoming Ad particles and infection. Our data provide the first evidence that virus-encoded PPxY motifs are required during virus entry, which may be of significance for several other pathogens

    The comparative effectiveness of abatacept versus anti-tumour necrosis factor switching for rheumatoid arthritis patients previously treated with an anti-tumour necrosis factor

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    OBJECTIVE: We compared the effectiveness of abatacept (ABA) versus a subsequent anti-tumour necrosis factor inhibitor (anti-TNF) in rheumatoid arthritis (RA) patients with prior anti-TNF use. METHODS: We identified RA patients from a large observational US cohort (2/1/2000-8/7/2011) who had discontinued at least one anti-TNF and initiated either ABA or a subsequent anti-TNF. Using propensity score (PS) matching (n:1 match), effectiveness was measured at 6 and 12 months after initiation based on mean change in Clinical Disease Activity Index (CDAI), modified American College of Rheumatology (mACR) 20, 50 and 70 responses, modified Health Assessment Questionnaire (mHAQ) and CDAI remission in adjusted regression models. RESULTS: The PS-matched groups included 431 ABA and 746 anti-TNF users at 6 months and 311 ABA and 493 anti-TNF users at 12 months. In adjusted analyses comparing response following treatment with ABA and anti-TNF, the difference in weighted mean change in CDAI (range 6-8) at 6 months (0.46, 95% CI -0.82 to 1.73) and 12 months was similar (-1.64, 95% CI -3.47 to 0.19). The mACR20 responses were similar at 6 (28-32%, p=0.73) and 12 months (35-37%, p=0.48) as were the mACR50 and mACR70 (12 months: 20-22%, p=0.25 and 10-12%, p=0.49, respectively). Meaningful change in mHAQ was similar at 6 and 12 months (30-33%, p=0.41 and 29-30%, p=0.39, respectively) as was CDAI remission rates (9-10%, p=0.42 and 12-13%, p=0.91, respectively). CONCLUSIONS: RA patients with prior anti-TNF exposures had similar outcomes if they switched to a new anti-TNF as compared with initiation of ABA

    Significance of sex in achieving sustained remission in the consortium of rheumatology researchers of north america cohort of rheumatoid arthritis patients

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    Objective To determine whether men with rheumatoid arthritis (RA) are more likely to achieve remission compared to women. Methods RA patients enrolled in the Consortium of Rheumatology Researchers of North America (CORRONA) cohort between October 2001 and January 2010 were selected for the present analyses. Detailed clinical, demographic, and drug utilization data were available at enrollment (baseline) and at subsequent followup visits. We examined the influence of sex on the Clinical Disease Activity Index remission score (≤2.8) using sustained remission or point remission as the primary outcome measure in multivariate stepwise logistic regression models. We stratified the data by RA duration at baseline (≤2 years or >2 years) to investigate whether RA duration had differential effects on remission in men and women. Results A total of 10,299 RA patients (2,406 men and 7,893 women) were available for this study. In both early and established RA, women had more severe disease at baseline with worse disease activity measures, modified Health Assessment Questionnaire disability index score, pain on a visual analog scale, and depression. Women were also more likely to have been treated with disease‐modifying antirheumatic drugs and anti–tumor necrosis factor therapy compared to men. In the regression models, male sex was associated with sustained remission in early RA (odds ratio [OR] 1.38, 95% confidence interval [95% CI] 1.07–1.78, P = 0.01), but not in established RA. However, for point remission, an inverse association was observed with male sex in established RA (OR 0.65, 95% CI 0.48–0.87, P = 0.005) and not in early RA. Conclusion Within the large real‐life CORRONA cohort of RA patients, men were more likely to achieve sustained remission compared to women in early RA, although not in established RA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94462/1/21762_ftp.pd

    Refining iPSC-based 3D neural cell models and characterization tools to address brain microenvironment-related diseases

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    Brain microenvironment plays important roles in neurodevelopment and pathology and can affect therapy efficacy. Neural cell culture typically relies on the use of heterologous matrices that poorly resemble brain extracellular matrix (ECM) or reflect its pathological features. We have shown that perfusion bioreactor-based 3D differentiation of iPSC-derived human neural stem cells (hiPSC-NSC) sustains the concomitant differentiation of the three neural lineages (neurospheroids). If this neurospheroid culture strategy also allows deposition of native neural ECM it would be possible to (i) mimic cellular and microenvironment remodeling during neural differentiation, without the confounding effects of exogenous matrices and (ii) recapitulate pathological phenotypic features of diseases in which homotypic/ heterotypic cell-cell interactions and ECM are relevant. To characterize the neural extracellular space we employed quantitative transcriptomic (NGS) and proteome (SWATH-MS) analysis. Neurogenic developmental pathways were recapitulated in neurospheroids, with significant changes in cell membrane and ECM composition along differentiation; a significant enrichment in structural proteoglycans, typical of brain ECM, a downregulation of basement membrane proteins constituents and a higher expression of synaptic and ion transport machinery were observed. Neurospheroids were generated using hiPSC-NSC derived from Mucopolysaccharidosis type VII (MPS VII) patients. MPS VII is a rare neuronopathic lysosomal storage disease caused by deficient β-glucuronidase (β-gluc) activity, leading to glycosaminoglycan (GAGs) accumulation in the brain. The main MPS VII molecular hallmarks were recapitulated, e.g. accumulation og GAGs. By combining the neurospheroid culture with a 3D neuronal connectivity assay based on calcium imaging analysis we refined a new analytical strategy to characterize neuronal connectivity defects in a more predictive setting. We showed that MPS VII neurospheroids presented reduced neuronal activity and disturbances in network functionality, with alterations in connectivity and synchronization. These data provide insights into the interplay between reduced β-gluc activity, GAGs accumulation, alterations in neuronal network and its impact on MPS VII-associated cognitive defects Applying the characterization tools refined in this work to cope with 3D neurospheroid cultures, namely the neuronal connectivity assay, we provide a new platform to unveil the cellular processes responsible for brain dysfunction in neurological disorders and to test and optimize new therapies. Acknowledgments: iNOVA4Health – UID/Multi/04462/2013, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement, is acknowledged. PD/BD/52473/2014, PD/BD/52481/2014, and PD/BD/128371/2017 PhD fellowships funded by FCT, Portugal. N.R. is supported by the European Research Council Starting Grant 337327. MS data were obtained by UniMS – Mass Spectrometry Unit, ITQB and iBET, Oeiras, Portugal

    Randomly Crosslinked Macromolecular Systems: Vulcanisation Transition to and Properties of the Amorphous Solid State

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    As Charles Goodyear discovered in 1839, when he first vulcanised rubber, a macromolecular liquid is transformed into a solid when a sufficient density of permanent crosslinks is introduced at random. At this continuous equi- librium phase transition, the liquid state, in which all macromolecules are delocalised, is transformed into a solid state, in which a nonzero fraction of macromolecules have spontaneously become localised. This solid state is a most unusual one: localisation occurs about mean positions that are distributed homogeneously and randomly, and to an extent that varies randomly from monomer to monomer. Thus, the solid state emerging at the vulcanisation transition is an equilibrium amorphous solid state: it is properly viewed as a solid state that bears the same relationship to the liquid and crystalline states as the spin glass state of certain magnetic systems bears to the paramagnetic and ferromagnetic states, in the sense that, like the spin glass state, it is diagnosed by a subtle order parameter. In this review we give a detailed exposition of a theoretical approach to the physical properties of systems of randomly, permanently crosslinked macromolecules. Our primary focus is on the equilibrium properties of such systems, especially in the regime of Goodyear's vulcanisation transition.Comment: Review Article, REVTEX, 58 pages, 3 PostScript figure

    Mutant p53R270H drives altered metabolism and increased invasion in pancreatic ductal adenocarcinoma

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    Pancreatic cancer is characterized by nearly universal activating mutations in KRAS. Among other somatic mutations, TP53 is mutated in more than 75% of human pancreatic tumors. Genetically engineered mice have proven instrumental in studies of the contribution of individual genes to carcinogenesis. Oncogenic Kras mutations occur early during pancreatic carcinogenesis and are considered an initiating event. In contrast, mutations in p53 occur later during tumor progression. In our model, we recapitulated the order of mutations of the human disease, with p53 mutation following expression of oncogenic Kras. Further, using an inducible and reversible expression allele for mutant p53, we inactivated its expression at different stages of carcinogenesis. Notably, the function of mutant p53 changes at different stages of carcinogenesis. Our work establishes a requirement for mutant p53 for the formation and maintenance of pancreatic cancer precursor lesions. In tumors, mutant p53 becomes dispensable for growth. However, it maintains the altered metabolism that characterizes pancreatic cancer and mediates its malignant potential. Further, mutant p53 promotes epithelial-mesenchymal transition (EMT) and cancer cell invasion. This work generates new mouse models that mimic human pancreatic cancer and expands our understanding of the role of p53 mutation, common in the majority of human malignancies

    iPSC-derived neurospheroids recapitulate development and pathological signatures of human brain microenvironment

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    Brain microenvironment plays an important role in neurodevelopment and pathology, where extracellular matrix (ECM) and soluble factors modulate multiple cellular processes. Neural cell culture typically relies on the use of heterologous matrices that poorly resemble the brain ECM or reflect its pathological features. We have previously demonstrated that perfusion stirred-tank bioreactor-based 3D differentiation of human neural stem cells (NSC) - pSTR-neurospheroids, sustains the concomitant differentiation of the three neural cell lineages (neurons, astrocytes and oligodendrocytes) and the establishment of physiologically relevant cell-cell interactions. Here, we hypothesized that if the pSTR-neurospheroid strategy would also allow the deposition of native neural ECM components and diffusion of secreted factors, it would be possible to: (i) mimic the cellular and microenvironment remodeling occurring during neural differentiation without the confounding effects of exogenous matrices; (ii) recapitulate the pathological phenotypes of diseases in which alteration of homotypic and heterotypic cell-cell interactions and ECM components are relevant. To demonstrate the first point, we analyzed pSTR-neurospheroid differentiation by quantitative transcriptome (NGS) and proteome (SWATH-MS). Data showed that neurogenic developmental pathways were recapitulated, with significant changes at cell membrane and ECM composition, diverging from the 2D differentiation profile. A significant enrichment in structural proteoglycans typical of brain ECM, along with downregulation of basement membrane constituents was observed. Moreover, higher expression of synaptic and ion transport machinery in pSTR-neurospheroids suggest higher neuronal maturation than in 2D. Having shown recapitulation of neural microenvironmental dynamics in pSTR-neurospheroids, we used Mucopolysaccharidosis VII (MPSVII) as a disease case study. MPS VII is a lysosomal storage disease caused by deficient β-glucuronidase (β-gluc) activity, which leads to accumulation of glycosaminoglycans (GAGs) in many tissues, including the brain. In pSTR-neurospheroids generated from hiPSC of a MPS VII patient, the main molecular disease hallmarks were recapitulated, namely accumulation of GAGs. Notably, MPS VII neurospheroids showed reduced neuronal activity and a disturbance in network functionality, with alterations both in connectivity and synchronization, not observed in 2D cultures. These data provide insight into the interplay between reduced β-gluc activity, GAG accumulation, alterations in the neural network, and its impact on MPS VII-associated cognitive defects. Overall we demonstrate that neural cellular and extracellular developmental and pathological features are recapitulated in healthy and diseased pSTR-neurospheroids, respectively. These can be valuable in vitro models to address molecular defects associated with neurological disorders that affect neural microenvironment homeostasis. Moreover, the 3D neuronal connectivity assay developed is a new tool with potential to assess other lysosomal storage diseases and neurodegenerative diseases that have variable phenotypes. Acknowledgements: SFRH/BD/78308/2011, SFRH/BD/52202/2013 and SFRH/BD/52473/2014 PhD fellowships from FCT, Portugal and iNOVA4Health-UID/Multi/04462/2013, supported by FCT/ MEC, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement
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