105 research outputs found

    Enhanced antigen presentation in the absence of the invariant chain endosomal localization signal.

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    The cytosolic tail of the major histocompatibility complex class II-associated invariant chain (Ii) molecule is thought to contain the endosomal localization signal that directs and/or retains newly synthesized class II within the endosomal antigen processing compartment. To determine the role of this signal in class II transport and antigen presentation we have generated class II-positive L cell transfectants that coexpress wild type or truncated forms of Ii. Deletion of the endosomal localization signal from Ii results in rapid transport of class II-Ii complexes to the cell surface. Once at the cell surface, the complex is efficiently internalized, Ii is degraded, and class II free of Ii is recycled back to the plasma membrane. Interestingly, the truncated form of Ii is still able to increase the efficiency of antigen presentation to T cells. These data suggest that the ability of Ii to enhance antigen presentation is not limited to Golgi apparatus-endosomal sorting and raise the possibility that endocytosed class II can form immunogenic complexes with newly processed antigen

    Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory:A State-of-the-Art Review

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    Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.</p

    Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory:A State-of-the-Art Review

    Get PDF
    Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.</p

    Magazines for youth? : a comparative content analysis of two New Zealand juvenile periodicals

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    This research project investigated the readership of two New Zealand youth magazines during the period 1945-1947. The magazines, Conquest: the magazine for youth, and Junior Digest: the magazine for girls and boys, were subjected to a content analysis which attempted to capture details of the readers, and describe the types of articles in each magazine in an attempt to discover what kinds of reading tastes young people of the period had. The project produced a description of the kinds of content that were present in the two magazines and in what quantities. By combining this content analysis with demographic data of the readers themselves, who contributed to the magazines by sending letters, jokes, competition entries and jokes, this research was able to show who the specific group of readers were and make conclusions about what they liked. By contrasting the results, it was determined that there were slight differences in the content of the magazines which may have accounted for the failure of Conquest to continue after July 1947, but that the data provided by the content analysis alone was insufficient to allow insight into the broader periodical reading tastes of New Zealand youth in the second half of the 1940s

    Calculating Ensemble Averaged Descriptions of Protein Rigidity without Sampling

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    Previous works have demonstrated that protein rigidity is related to thermodynamic stability, especially under conditions that favor formation of native structure. Mechanical network rigidity properties of a single conformation are efficiently calculated using the integer body-bar Pebble Game (PG) algorithm. However, thermodynamic properties require averaging over many samples from the ensemble of accessible conformations to accurately account for fluctuations in network topology. We have developed a mean field Virtual Pebble Game (VPG) that represents the ensemble of networks by a single effective network. That is, all possible number of distance constraints (or bars) that can form between a pair of rigid bodies is replaced by the average number. The resulting effective network is viewed as having weighted edges, where the weight of an edge quantifies its capacity to absorb degrees of freedom. The VPG is interpreted as a flow problem on this effective network, which eliminates the need to sample. Across a nonredundant dataset of 272 protein structures, we apply the VPG to proteins for the first time. Our results show numerically and visually that the rigidity characterizations of the VPG accurately reflect the ensemble averaged properties. This result positions the VPG as an efficient alternative to understand the mechanical role that chemical interactions play in maintaining protein stability

    Trapping \u3ci\u3ePhyllophaga \u3c/i\u3espp. (Coleoptera: Scarabaeidae: Melolonthinae) in the United States and Canada using sex attractants.

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    The sex pheromone of the scarab beetle, Phyllophaga anxia, is a blend of the methyl esters of two amino acids, L-valine and L-isoleucine. A field trapping study was conducted, deploying different blends of the two compounds at 59 locations in the United States and Canada. More than 57,000 males of 61 Phyllophaga species (Coleoptera: Scarabaeidae: Melolonthinae) were captured and identified. Three major findings included: (1) widespread use of the two compounds [of the 147 Phyllophaga (sensu stricto) species found in the United States and Canada, males of nearly 40% were captured]; (2) in most species intraspecific male response to the pheromone blends was stable between years and over geography; and (3) an unusual pheromone polymorphism was described from P. anxia. Populations at some locations were captured with L-valine methyl ester alone, whereas populations at other locations were captured with L-isoleucine methyl ester alone. At additional locations, the L-valine methyl ester-responding populations and the L-isoleucine methyl ester-responding populations were both present, producing a bimodal capture curve. In southeastern Massachusetts and in Rhode Island, in the United States, P. anxia males were captured with blends of L-valine methyl ester and L-isoleucine methyl ester
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