921 resultados para Activin Receptors, Type I


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Protease-activated receptors (PARs) are widely distributed in human airways. They couple to G-proteins and are activated after proteolytic cleavage of the N terminus of the receptor. Evidence is growing that PAR subtype 2 plays a pivotal role in inflammatory airway diseases, such as allergic asthma or bronchitis. However, nothing is known about the effects of PAR-2 on electrolyte transport in the native airways. PAR-2 is expressed in airway epithelial cells, where they are activated by mast cell tryptase, neutrophil proteinase 3, or trypsin. Recent studies produced conflicting results about the functional consequence of PAR-2 stimulation. Here we report that stimulation of PAR-2 receptors in mouse and human airways leads to a change in electrolyte transport and a shift from absorption to secretion. Although PAR-2 appears to be expressed on both sides of the epithelium, only basolateral stimulation results in inhibition of amiloride sensitive Na+ conductance and stimulation of both luminal Cl- channels and basolateral K+ channels. The present data indicate that these changes occur through activation of phospholipase C and increase in intracellular Ca2+, which activates basolateral SK4 K+ channels and luminal Ca2+-dependent Cl- channels. In addition, the present data suggest a PAR-2 mediated release of prostaglandin E2, which may contribute to the secretory response. In conclusion, these results provide further evidence for a role of PAR-2 in inflammatory airway disease: stimulation of these receptors may cause accumulation of airway surface liquid, which, however, may help to flush noxious stimuli away from the affected airways. ©2005 FASEB

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In humans, a polymorphic gene encodes the drug-metabolizing enzyme NATI (arylamine N-acetyltransferase Type 1), which is widely expressed throughout the body. While the protein-coding region of NATI is contained within a single exon, examination of the human EST (expressed sequence tag) database at the NCBI revealed the presence of nine separate exons, eight of which were located in the 5'non-coding region of NATI. Differential splicing produced at least eight unique mRNA isoforms that could be grouped according to the location of the first exon, which suggested that NATI expression occurs from three alternative promoters. Using RT (reverse transcriptase)-PCR, we identified one major transcript in various epithelial cells derived from different tissues. In contrast, multiple transcripts were observed in blood-derived cell lines (CEM, THP-1 and Jurkat), with a novel variant, not identified in the EST database, found in CEM cells only. The major splice variant increased gene expression 9-11-fold in a luciferase reporter assay, while the other isoforrns were similar or slightly greater than the control. We examined the upstream region of the most active splice variant in a promoter-reporter assay, and isolated a 257 bp sequence that produced maximal promoter activity. This sequence lacked a TATA box, but contained a consensus Sp1 site and a CAAT box, as well as several other putative transcription-factor-binding sites. Cell-specific expression of the different NATI transcripts may contribute to the variation in NATI activity in vivo.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A 3.9 kb DNA fragment of human osteocalcin promoter and 3.6 kb DNA fragment of the rat collagen type1a1 promoter linked with visually distinguishable GFP isomers, topaz and cyan, were used for multiplex analysis of osteoblast lineage progression. Three patterns of dual transgene, expression can be appreciated in primary bone cell cultures derived from the transgenic mice and by histology of their corresponding bones. Our data support the interpretation that strong pOBCol3.6GFPcyan alone is found in newly formed osteoblasts, while strong pOBCol3.6GFPcyan and hOC-GFPtpz are present in osteoblasts actively making a new matrix. Osteoblasts expressing strong hOC-GFPtpz and weak pOBCol3.6GF-Pcyan are also present and may or may not be producing mineralized matrix. This multiplex approach reveals the heterogeneity within the mature osteoblast population that cannot be appreciated by current histological methods. It should be useful to identify and isolate populations of cells within an osteoblast lineage as they progress through stages of differentiation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The sensitivities of type I and IIA fibre Bragg gratings written to different reflectivities in SMF-28 and B/Ge fibres to ionizing radiation up to 0.54MGy are investigated. The Bragg wavelength shows a small and rapid increase at the start of irradiation followed by either a plateau (type I) or a decrease (type IIA).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We report experimental findings for tailoring the temperature and strain coefficients of Type I and Type IA fibre Bragg gratings by influencing the photosensitivity presensitization of the host optical fibre. It is shown that by controlling the level of hydrogen saturation, via hot and cold hydrogenation, it is possible to produce gratings with lower thermal coefficients. Furthermore, there is a larger difference between the Type I and Type IA thermal coefficients and a significant improvement in the matrix condition number, which impacts the ability to recover accurate temperature and strain data using the Type 1-1A dual grating sensor. © 2006 IOP Publishing Ltd.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The use of the Type I and Type II scheme, first introduced and used by fiber Bragg grating researchers, has recently been adopted by the ultrafast laser direct-write photonics community to classify the physical geometry of waveguides written into glasses and crystals. This has created confusion between the fiber Bragg grating and direct-write photonics community. Here we propose a return to the original basis of the classification based on the characteristics of the material modification rather than the physical geometry of the waveguide.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The sensitivities of type I and IIA fibre Bragg gratings written to different reflectivities in SMF-28 and B/Ge fibres to ionizing radiation up to 0.54MGy are investigated. The Bragg wavelength shows a small and rapid increase at the start of irradiation followed by either a plateau (type I) or a decrease (type IIA).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A cikkben a szerző a piac és a kormányzat kudarcaiból kiindulva azonosítja a közjó elérését célzó harmadik rendszer, az etikai felelősség kudarcait. Statisztikai analógiát használva elsőfajú kudarcként azonosítja, mikor az etikát nem veszik figyelembe, pedig szükség van rá. Ugyanakkor másodfajú kudarcként kezeli az etika profitnövelést célzó használatát, mely megtéveszti az érintetteteket, így még szélesebb utat enged az opportunista üzleti tevékenységnek. Meglátása szerint a három rendszer egymást nemcsak kiegészíti, de kölcsönösen korrigálja is. Ez az elsőfajú kudarc esetében általánosabb, a másodfajú kudarc megoldásához azonban a gazdasági élet alapvetéseinek átfogalmazására, az önérdek és az egydimenziós teljesítményértékelés helyett egy új, holisztikusabb szemléletű közgazdaságra van szükség. _______ In the article the author identifies the errors of ethical responsibility. That is the third system to attain common good, but have similar failures like the other two: the hands of the market and the government. Using statistical analogy the author identifies Type I error when ethics are not considered but it should be (null hypothesis is rejected however it’s true). She treats the usage of ethics to extend profit as Type II error. This misleads the stakeholders and makes room for opportunistic behaviour in business (null hypothesis is accepted in turn it’s false). In her opinion the three systems: the hand of the market, the government and the ethical management not only amend but interdependently correct each other. In the case of Type I error it is more general. Nevertheless to solve the Type II error we have to redefine the core principles of business. We need a more holistic approach in economics instead of self-interest and one-dimensional interpretation of value.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.