845 research outputs found

    THE IMMEDIATE EFFECT OF A GENTLE HEEL STRIKE ON PERONEAL MUSCLE PRE-LANDING ACTIVATION DURING PROLONGED TREADMILL RUNNING IN MALES

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    Ankle sprains are common in runners. Inactive peroneal longus (PL) is one of the main contributors. The aim of this project was to study the immediate effect of running with a gentle heel strike (GHS) on pre-landing activation of the PL. It was hypothesised that GHS would pre-activate the PL to a greater extent. 11 healthy participants partook in two separate trials. The first involved running on a force plate treadmill with normally, the second with ~70% of mean heel pressure (MHP). GHS showed higher pre-landing PL activated level. There was data showing significant differences between groups at multiple timepoints. The present study showed that running with ~70% MHP compared with 100% increased PL activation for pre-landing phases. Further study should be implemented to see the fatigue level of PL during pro-longed running when running gently

    Reduction in squamous cell carcinomas in mouse skin by dietary zinc supplementation.

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    Inadequate dietary Zn consumption increases susceptibility to esophageal and other cancers in humans and model organisms. Since Zn supplementation can prevent cancers in rodent squamous cell carcinoma (SCC) models, we were interested in determining if it could have a preventive effect in a rodent skin cancer model, as a preclinical basis for considering a role for Zn in prevention of human nonmelanoma skin cancers, the most frequent cancers in humans. We used the 7,12-dimethyl benzanthracene carcinogen/phorbol myristate acetate tumor promoter treatment method to induce skin tumors in Zn-sufficient wild-type and Fhit (human or mouse protein) knockout mice. Fhit protein expression is lost in \u3e50% of human cancers, including skin SCCs, and Fhit-deficient mice show increased sensitivity to carcinogen induction of tumors. We hypothesized that: (1) the skin cancer burdens would be reduced by Zn supplementation; (2) Fhit(-/-) (Fhit, murine fragile histidine triad gene) mice would show increased susceptibility to skin tumor induction versus wild-type mice. 30 weeks after initiating treatment, the tumor burden was increased ~2-fold in Fhit(-/-) versus wild-type mice (16.2 versus 7.6 tumors, P \u3c 0.001); Zn supplementation significantly reduced tumor burdens in Fhit(-/-) mice (males and females combined, 16.2 unsupplemented versus 10.3 supplemented, P = 0.001). Most importantly, the SCC burden was reduced after Zn supplementation in both strains and genders of mice, most significantly in the wild-type males (P = 0.035). Although the mechanism(s) of action of Zn supplementation in skin tumor prevention is not known in detail, the Zn-supplemented tumors showed evidence of reduced DNA damage and some cohorts showed reduced inflammation scores. The results suggest that mild Zn supplementation should be tested for prevention of skin cancer in high-risk human cohorts

    Autophosphorylated CaMKIIα Acts as a Scaffold to Recruit Proteasomes to Dendritic Spines

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    The molecular mechanisms regulating the ubiquitin proteasome system (UPS) at synapses are poorly understood. We report that CaMKIIα—an abundant postsynaptic protein kinase—mediates the activity-dependent recruitment of proteasomes to dendritic spines in hippocampal neurons. CaMKIIα is biochemically associated with proteasomes in the brain. CaMKIIα translocation to synapses is required for activity-induced proteasome accumulation in spines, and is sufficient to redistribute proteasomes to postsynaptic sites. CaMKIIα autophosphorylation enhances its binding to proteasomes and promotes proteasome recruitment to spines. In addition to this structural role, CaMKIIα stimulates proteasome activity by phosphorylating proteasome subunit Rpt6 on Serine 120. However, CaMKIIα translocation, but not its kinase activity, is required for activity-dependent degradation of polyubiquitinated proteins in spines. Our findings reveal a scaffolding role of postsynaptic CaMKIIα in activity-dependent proteasome redistribution, which is commensurate with the great abundance of CaMKIIα in synapses.Howard Hughes Medical Institute (Investigator

    Regulation of Synaptic Structure and Function by FMRP-Associated MicroRNAs miR-125b and miR-132

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    MicroRNAs (miRNAs) are noncoding RNAs that suppress translation of specific mRNAs. The miRNA machinery interacts with fragile X mental retardation protein (FMRP), which functions as translational repressor. We show that miR-125b and miR-132, as well as several other miRNAs, are associated with FMRP in mouse brain. miR-125b and miR-132 had largely opposing effects on dendritic spine morphology and synaptic physiology in hippocampal neurons. FMRP knockdown ameliorates the effect of miRNA overexpression on spine morphology. We identified NMDA receptor subunit NR2A as a target of miR-125b and show that NR2A mRNA is specifically associated with FMRP in brain. In hippocampal neurons, NR2A expression is negatively regulated through its 3′ UTR by FMRP, miR-125b, and Argonaute 1. Regulation of NR2A 3′UTR by FMRP depends in part on miR-125b. Because NMDA receptor subunit composition profoundly affects synaptic plasticity, these observations have implications for the pathophysiology of fragile X syndrome, in which plasticity is altered.Deutsche Forschungsgemeinschaft (ED157/1, postdoctoral fellowship)National Cancer Institute (U.S.) (NCI PO1-CA42063)National Cancer Institute (U.S.) (NCI P30-CA14051)National Cancer Institute (U.S.) (Cancer Center Support (Core) Grant)National Cancer Institute (U.S.) (NCI K99-CA131474)Howard Hughes Medical Institute (Investigator

    Planetary Rover Simulation for Lunar Exploration Missions

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    When planning planetary rover missions it is useful to develop intuition and skills driving in, quite literally, alien environments before incurring the cost of reaching said locales. Simulators make it possible to operate in environments that have the physical characteristics of target locations without the expense and overhead of extensive physical tests. To that end, NASA Ames and Open Robotics collaborated on a Lunar rover driving simulator based on the open source Gazebo simulation platform and leveraging ROS (Robotic Operating System) components. The simulator was integrated with research and mission software for rover driving, system monitoring, and science instrument simulation to constitute an end-to-end Lunar mission simulation capability. Although we expect our simulator to be applicable to arbitrary Lunar regions, we designed to a reference mission of prospecting in polar regions. The harsh lighting and low illumination angles at the Lunar poles combine with the unique reflectance properties of Lunar regolith to present a challenging visual environment for both human and computer perception. Our simulator placed an emphasis on high fidelity visual simulation in order to produce synthetic imagery suitable for evaluating human rover drivers with navigation tasks, as well as providing test data for computer vision software development.In this paper, we describe the software used to construct the simulated Lunar environment and the components of the driving simulation. Our synthetic terrain generation software artificially increases the resolution of Lunar digital elevation maps by fractal synthesis and inserts craters and rocks based on Lunar size-frequency distribution models. We describe the necessary enhancements to import large scale, high resolution terrains into Gazebo, as well as our approach to modeling the visual environment of the Lunar surface. An overview of the mission software system is provided, along with how ROS was used to emulate flight software components that had not been developed yet. Finally, we discuss the effect of using the high-fidelity synthetic Lunar images for visual odometry. We also characterize the wheel slip model, and find some inconsistencies in the produced wheel slip behaviour

    MS4A1 Dysregulation in Asbestos-Related Lung Squamous Cell Carcinoma Is Due to CD20 Stromal Lymphocyte Expression

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    Asbestos-related lung cancer accounts for 4–12% of lung cancers worldwide. We have previously identified ADAM28 as a putative oncogene involved in asbestos-related lung adenocarcinoma (ARLC-AC). We hypothesised that similarly gene expression profiling of asbestos-related lung squamous cell carcinomas (ARLC-SCC) may identify candidate oncogenes for ARLC-SCC. We undertook a microarray gene expression study in 56 subjects; 26 ARLC-SCC (defined as lung asbestos body (AB) counts >20AB/gram wet weight (gww) and 30 non-asbestos related lung squamous cell carcinoma (NARLC-SCC; no detectable lung asbestos bodies; 0AB/gww). Microarray and bioinformatics analysis identified six candidate genes differentially expressed between ARLC-SCC and NARLC-SCC based on statistical significance (p<0.001) and fold change (FC) of >2-fold. Two genes MS4A1 and CARD18, were technically replicated by qRT-PCR and showed consistent directional changes. As we also found MS4A1 to be overexpressed in ARLC-ACs, we selected this gene for biological validation in independent test sets (one internal, and one external dataset (2 primary tumor sets)). MS4A1 RNA expression dysregulation was validated in the external dataset but not in our internal dataset, likely due to the small sample size in the test set as immunohistochemical (IHC) staining for MS4A1 (CD20) showed that protein expression localized predominantly to stromal lymphocytes rather than tumor cells in ARLC-SCC. We conclude that differential expression of MS4A1 in this comparative gene expression study of ARLC-SCC versus NARLC-SCC is a stromal signal of uncertain significance, and an example of the rationale for tumor cell enrichment in preparation for gene expression studies where the aim is to identify markers of particular tumor phenotypes. Finally, our study failed to identify any strong gene candidates whose expression serves as a marker of asbestos etiology. Future research is required to determine the role of stromal lymphocyte MS4A1 dysregulation in pulmonary SCCs caused by asbestos

    Bruton's Tyrosine Kinase Inhibition Attenuates the Cardiac Dysfunction Caused by Cecal Ligation and Puncture in Mice

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    Sepsis is one of the most prevalent diseases in the world. The development of cardiac dysfunction in sepsis results in an increase of mortality. It is known that Bruton's tyrosine kinase (BTK) plays a role in toll-like receptor signaling and NLRP3 inflammasome activation, two key components in the pathophysiology of sepsis and sepsis-associated cardiac dysfunction. In this study we investigated whether pharmacological inhibition of BTK (ibrutinib 30 mg/kg and acalabrutinib 3 mg/kg) attenuates sepsis associated cardiac dysfunction in mice. 10-week old male C57BL/6 mice underwent CLP or sham surgery. One hour after surgery mice received either vehicle (5% DMSO + 30% cyclodextrin i.v.), ibrutinib (30 mg/kg i.v.), or acalabrutinib (3 mg/kg i.v.). Mice also received antibiotics and an analgesic at 6 and 18 h. After 24 h, cardiac function was assessed by echocardiography in vivo. Cardiac tissue underwent western blot analysis to determine the activation of BTK, NLRP3 inflammasome and NF-\u3baB pathway. Serum analysis of 33 cytokines was conducted by a multiplex assay. When compared to sham-operated animals, mice subjected to CLP demonstrated a significant reduction in ejection fraction (EF), fractional shortening (FS), and fractional area change (FAC). The cardiac tissue from CLP mice showed significant increases of BTK, NF-\u3baB, and NLRP3 inflammasome activation. CLP animals resulted in a significant increase of serum cytokines and chemokines (TNF-\u3b1, IL-6, IFN-\u3b3, KC, eotaxin-1, eotaxin-2, IL-10, IL-4, CXCL10, and CXCL11). Delayed administration of ibrutinib and acalabrutinib attenuated the decline of EF, FS, and FAC caused by CLP and also reduced the activation of BTK, NF-\u3baB, and NLRP3 inflammasome. Both ibrutinib and acalabrutinib significantly suppressed the release of cytokines and chemokines. Our study revealed that delayed intravenous administration of ibrutinib or acalabrutinib attenuated the cardiac dysfunction associated with sepsis by inhibiting BTK, reducing NF-\u3baB activation and the activation of the inflammasome. Cytokines associated with sepsis were significantly reduced by both BTK inhibitors. Acalabrutinib is found to be more potent than ibrutinib and could potentially prove to be a novel therapeutic in sepsis. Thus, the FDA-approved BTK inhibitors ibrutinib and acalabrutinib may be repurposed for the use in sepsis

    Outcome of sustained virological responders with histologically advanced chronic hepatitis C

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    Retrospective studies suggest that subjects with chronic hepatitis C and advanced fibrosis who achieve a sustained virological response (SVR) have a lower risk of hepatic decompensation and hepatocellular carcinoma (HCC). In this prospective analysis, we compared the rate of death from any cause or liver transplantation, and of liver-related morbidity and mortality, after antiviral therapy among patients who achieved SVR, virologic nonresponders (NR), and those with initial viral clearance but subsequent breakthrough or relapse (BT/R) in the HALT-C (Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis) Trial. Laboratory and/or clinical outcome data were available for 140 of the 180 patients who achieved SVR. Patients with nonresponse (NR; n = 309) or who experienced breakthrough or relapse (BT/R; n = 77) were evaluated every 3 months for 3.5 years and then every 6 months thereafter. Outcomes included death, liver-related death, liver transplantation, decompensated liver disease, and HCC. Median follow-up for the SVR, BT/R, and NR groups of patients was 86, 85, and 79 months, respectively. At 7.5 years, the adjusted cumulative rate of death/liver transplantation and of liver-related morbidity/mortality in the SVR group (2.2% and 2.7%, respectively) was significantly lower than that of the NR group (21.3% and 27.2%, P < 0.001 for both) but not the BT/R group (4.4% and 8.7%). The adjusted hazard ratio (HR) for time to death/liver transplantation (HR = 0.17, 95% confidence interval [CI] = 0.06-0.46) or development of liver-related morbidity/mortality (HR = 0.15, 95% CI = 0.06-0.38) or HCC (HR = 0.19, 95% CI = 0.04-0.80) was significant for SVR compared to NR. Laboratory tests related to liver disease severity improved following SVR. Conclusion: Patients with advanced chronic hepatitis C who achieved SVR had a marked reduction in death/liver transplantation, and in liver-related morbidity/mortality, although they remain at risk for HCC. (H EPATOLOGY 2010;)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78047/1/23744_ftp.pd

    (En)countering counterfeits in Bangkok: the urban spatial interlegalities of intellectual property law, enforcement and tolerance

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    In a Bangkok mall a fibreglass policeman warning against intellectual property (IP) piracy stands just metres away from vendors selling fake DVDs; a scene indicative of incomplete and unsuccessful attempts by foreign governments (the US and EU in particular) and corporate actors at enrolment towards ever-higher IP standards – the ‘IP ratchet’ that Drahos (2004 Intellectual property and pharmaceutical markets: a nodal governance approach Temple Law Review 77 401–24) describes. But the scene also reflects cultural resistance at the local level. Both readings exemplify the range of historical, cultural, and politico-legal factors at play that can only be understood through engagement with vendors and consumers in the markets and malls of Bangkok. IP laws may achieve partial ‘closure’ but are regularly changing, contested, variably enforced, and subject to existing social norms such as the ‘cult of imitation’, cultures of legal informality, and a lack of social contract. We found that this lack of legal closure was most pronounced in the day-to-day operation of the Pratunam Market. Whilst other sites host regular crack-downs by police, the IP-specific DSI force, and the Thai courts, markets like Pratunam are mostly immune despite being a transnational trade node for the production and export of counterfeit garments with other developing countries, and a non-conforming node in the IP enforcement context. In the face of persistent efforts to transpose Euro-American IP laws in countries like Thailand, alternative and resistant nodes representing ‘spaces of interlegalities’ are likely to persevere because of the historical context, and the socio-cultural norms of these places

    Transplantation of canine olfactory ensheathing cells producing chondroitinase ABC promotes chondroitin sulphate proteoglycan digestion and axonal sprouting following spinal cord injury

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    Olfactory ensheathing cell (OEC) transplantation is a promising strategy for treating spinal cord injury (SCI), as has been demonstrated in experimental SCI models and naturally occurring SCI in dogs. However, the presence of chondroitin sulphate proteoglycans within the extracellular matrix of the glial scar can inhibit efficient axonal repair and limit the therapeutic potential of OECs. Here we have used lentiviral vectors to genetically modify canine OECs to continuously deliver mammalian chondroitinase ABC at the lesion site in order to degrade the inhibitory chondroitin sulphate proteoglycans in a rodent model of spinal cord injury. We demonstrate that these chondroitinase producing canine OECs survived at 4 weeks following transplantation into the spinal cord lesion and effectively digested chondroitin sulphate proteoglycans at the site of injury. There was evidence of sprouting within the corticospinal tract rostral to the lesion and an increase in the number of corticospinal axons caudal to the lesion, suggestive of axonal regeneration. Our results indicate that delivery of the chondroitinase enzyme can be achieved with the genetically modified OECs to increase axon growth following SCI. The combination of these two promising approaches is a potential strategy for promoting neural regeneration following SCI in veterinary practice and human patients
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