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排序方式: 共有205条查询结果,搜索用时 31 毫秒
201.
Alvarez JI Dodelet-Devillers A Kebir H Ifergan I Fabre PJ Terouz S Sabbagh M Wosik K Bourbonnière L Bernard M van Horssen J de Vries HE Charron F Prat A 《Science (New York, N.Y.)》2011,334(6063):1727-1731
The blood-brain barrier (BBB) is composed of tightly bound endothelial cells (ECs) and perivascular astrocytes that regulate central nervous system (CNS) homeostasis. We showed that astrocytes secrete Sonic hedgehog and that BBB ECs express Hedgehog (Hh) receptors, which together promote BBB formation and integrity during embryonic development and adulthood. Using pharmacological inhibition and genetic inactivation of the Hh signaling pathway in ECs, we also demonstrated a critical role of the Hh pathway in promoting the immune quiescence of BBB ECs by decreasing the expression of proinflammatory mediators and the adhesion and migration of leukocytes, in vivo and in vitro. Overall, the Hh pathway provides a barrier-promoting effect and an endogenous anti-inflammatory balance to CNS-directed immune attacks, as occurs in multiple sclerosis. 相似文献
202.
Muller CB Ride SM Fouke J Whitney T Denton DD Cantor N Nelson DJ Plummer J Busch-Vishniac I Meyers C Rosser SV Schiebinger L Roberts E Burgess D Beeson C Metz SS Sanders L Watford BA Ivey ES Frank Fox M Wettack S Klawe M Wulf WA Girgus J Leboy PS Babco EL Shanahan B Didion C Chubin DE Frize M Ganter SL Nalley EA Franz J Abruña HD Strober MH Zimmer Daniels J Carter EA Rhodes JH Schrijver I Zakian VA Simons B Martin U Boaler J Jolluck KR Mankekar P Gray RM Conkey MW Stansky P Xie A Martin P 《Science (New York, N.Y.)》2005,307(5712):1043
203.
Nene V Wortman JR Lawson D Haas B Kodira C Tu ZJ Loftus B Xi Z Megy K Grabherr M Ren Q Zdobnov EM Lobo NF Campbell KS Brown SE Bonaldo MF Zhu J Sinkins SP Hogenkamp DG Amedeo P Arensburger P Atkinson PW Bidwell S Biedler J Birney E Bruggner RV Costas J Coy MR Crabtree J Crawford M Debruyn B Decaprio D Eiglmeier K Eisenstadt E El-Dorry H Gelbart WM Gomes SL Hammond M Hannick LI Hogan JR Holmes MH Jaffe D Johnston JS Kennedy RC Koo H Kravitz S Kriventseva EV Kulp D Labutti K Lee E Li S Lovin DD 《Science (New York, N.Y.)》2007,316(5832):1718-1723
We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species. 相似文献
204.
205.
OBJECTIVES: To examine whether the occurrence of seasonal food insecurity was related to ethnicity, household wealth and perceived social support, and to assess whether social support was more efficacious in protecting against food insecurity in wealthier households. Secondary objectives were to assess the association between past food insecurity, current dietary intake and perceived health. DESIGN, SETTING AND SUBJECTS: A sample of 208 randomly selected mothers from two ethnic groups living in the same villages in rural Tanzania participated in a cross-sectional survey. RESULTS: Food insecurity was highly prevalent in this area, particularly among the poorer ethnic group. Half of ethnically Sukuma households fell into the most food-secure category, compared with only 20% of ethnically Pimbwe households. Among both groups, measures of household wealth and social support were strongly associated with food security. Interestingly, social support appeared to be more effective among the wealthier ethnic group/community. Past food insecurity was also related to current indicators of dietary intake and women's self-perceptions of health. CONCLUSION: Greater social support is associated with food security, suggesting that it may protect against the occurrence of seasonal food insecurity. Social support also interacts with wealth to offer greater protection against food insecurity, suggesting that increasing wealth at the community level may influence food insecurity through both direct and indirect means. Seasonal food insecurity also appears to have lasting effects that likely create and reinforce poverty. 相似文献