2,280 research outputs found

    The tyrosine kinase inhibitors methyl 2,5-dihydroxycinnamate and genistein reduce thrombin-evoked tyrosine phosphorylation and Ca2+ entry in human platelets

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    AbstractPlatelet activation is associated with the phosphorylation of a number of platelet proteins at tyrosine residues. The significance of this is unknown. Here we have investigated the effects of two tyrosine kinase inhibitors, methyl 2,5-dihydroxycinnamate and genistein, on thrombin-evoked protein tyrosine phosphorylation and Ca2+ signal generation in fura-2-loaded human platelets. Both compounds inhibited thrombin-evoked tyrosine phosphorylation and reduced the elevation of [Ca2+], in the presence, but not the absence, of external Ca2+. This suggested a selective inhibition of thrombin-evoked Ca2+ entry but not release from internal stores. Both compounds also reduced thrombin-evoked Mn2+ entry. In contrast, selective blockade of protein kinase C with Ro 31/8220-002 potentiated the thrombin-evoked Ca2+ signal. These data are compatible with a role for protein tyrosine phosphorylation contributing to thrombin-evoked Ca2+ entry in human platelets

    A stochastic model characterizing the dynamics of nitrogen concentration in an ecosystem

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    Call number: LD2668 .R4 STAT 1987 S73Master of ScienceStatistic

    Primary pulmonary hypertension is associated with reduced pulmonary vascular expression of type II bone morphogenetic protein receptor

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    BACKGROUND: Mutations in the type II receptor for bone morphogenetic protein (BMPR-II), a receptor member of the transforming growth factor-beta (TGF-beta) superfamily, underlie many familial and sporadic cases of primary pulmonary hypertension (PPH). METHODS AND RESULTS: Because the sites of expression of BMPR-II in the normal and hypertensive lung are unknown, we studied the cellular localization of BMPR-II and the related type I and II receptors for TGF-beta by immunohistochemistry in lung sections from patients undergoing heart-lung transplantation for PPH (n=11, including 3 familial cases) or secondary pulmonary hypertension (n=6) and from unused donor lungs (n=4). In situ hybridization was performed for BMPR-II mRNA. Patients were screened for the presence of mutations in BMPR2. In normal lungs, BMPR-II expression was prominent on vascular endothelium, with minimal expression in airway and arterial smooth muscle. In pulmonary hypertension cases, the intensity of BMPR-II immunostaining varied between lesions but involved endothelial and myofibroblast components. Image analysis confirmed that expression of BMPR-II was markedly reduced in the peripheral lung of PPH patients, especially in those harboring heterozygous BMPR2 mutations. A less marked reduction was also observed in patients with secondary pulmonary hypertension. In contrast, there was no difference in level of staining for TGF-betaRII or the endothelial marker CD31. CONCLUSIONS: The cellular localization of BMPR-II is consistent with a role in the formation of pulmonary vascular lesions in PPH, and reduced BMPR-II expression may contribute to the process of vascular obliteration in severe pulmonary hypertension

    Laboratory for Atmospheres 2007 Technical Highlights

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    The 2007 Technical Highlights describes the efforts of all members of the Laboratory for Atmospheres. Their dedication to advancing Earth Science through conducting research, developing and running models, designing instruments, managing projects, running field campaigns, and numerous other activities, is highlighted in this report

    Laboratory for Atmospheres: 2006 Technical Highlights

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    The 2006 Technical Highlights describes the efforts of all members of the Laboratory for Atmospheres. Their dedication to advancing Earth science through conducting research, developing and running models, designing instruments, managing projects, running field campaigns, and numerous other activities, are highlighted in this report

    Engineering Students in a Global World: Lehigh University\u27s Global Citizenship Program

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    As the world grows smaller and companies become increasingly international, engineering students with a global education will be in high demand. Given the constraints of the typical undergraduate engineering curriculum, it can be extremely challenging for engineering students to participate in activities designed to promote global awareness. Lehigh University’s answer to this challenge is the Global Citizenship Program (GCP), a “backpack” program designed to be accessible to any student on campus. The “backpack” metaphor means that all students should be able to assemble their own particular mix of additional courses and experiences in order to develop a global perspective that deepens their core disciplinary training. The GCP at Lehigh provides focus and structure to engineering students, providing opportunities for study abroad and organizing their humanities and social science electives into a coherent package of curricular and co-curricular experiences that maximizes the educational potential of these few non-engineering opportunities
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