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排序方式: 共有141条查询结果,搜索用时 15 毫秒
1.
Perla A Vargas Pippa M Simpson Margo Bushmiaer Rajiv Goel Craig A Jones James S Magee Charles R Feild Stacie M Jones 《Annals of allergy, asthma & immunology》2006,96(6):787-793
BACKGROUND: Children with poorly controlled asthma are at high risk of airway remodeling, sleep disruption, school absenteeism, and limited participation in activities. OBJECTIVE: To determine asthma prevalence and characterize disease severity and burden in school-aged children. METHOD: A case-finding study was conducted via a multiple-choice questionnaire and asthma algorithm. Items used for analysis include physician diagnosis of asthma, symptom severity, and health care utilization. The chi2 test was used to determine the significance of differences among cases. Logistic regression was used to evaluate the association of patient factors and asthma indicators. RESULTS: Of the 5,417 children surveyed, 1,341 (25%) were classified as being at risk of asthma. Of these asthma cases, 55% were positive by diagnosis and algorithm (active), 10% were positive per algorithm alone (suspected), and 35% were positive per diagnosis alone (nonactive). Only 14% of all asthma cases reported experiencing no respiratory symptoms (< 1% active, 2% suspected, and 40% nonactive) compared with 75% of noncases. Also, 75% of noncases reported never missing school compared with 19%, 33%, and 54% of active, suspected, and nonactive asthma cases. African American race, Medicaid enrollment, and male sex were independent predictors of asthma risk. Similarly, African American race, Medicaid enrollment, age, and persistent asthma were independent predictors of emergency department use among asthma cases. DISCUSSION: Prevalence of active symptoms suggestive of poor asthma control was extremely high among urban, minority children enrolled in Arkansas' largest public school district. Poor asthma control greatly affects quality of life, including school attendance and performance. Interventions should raise expectations and emphasize the importance of achieving asthma control. 相似文献
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M A Brewster R S Kirby C R Feild C M Cunniff 《Public health reports (Washington, D.C. : 1974)》1992,107(3):290-296
Planning of service delivery systems for children with special health care needs would be enhanced by knowledge of numbers of cases anticipated in defined geographic areas. A method is described for predicting numbers of children who will likely have mental retardation sufficient to require special education services, based on the birth prevalence of birth defects and clinicians' estimates of the likelihood of mental retardation associated with each specific birth defect. This method is applied to the 1980-82 birth cohort of a 28-county area of south and central Arkansas, and it is compared with special education enrollment data for children ages 6 to 8 in academic year 1988-89. According to this estimate, children with birth defects may account for 32 to 56 percent of the cases of mental retardation among 6- to 8-year-olds reported by the public schools. 相似文献
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Stomatal plugs of Drimys winteri (Winteraceae) protect leaves from mist but not drought 总被引:1,自引:0,他引:1 下载免费PDF全文
Taylor S. Feild Maciej A. Zwieniecki Michael J. Donoghue N. Michele Holbrook 《Proceedings of the National Academy of Sciences of the United States of America》1998,95(24):14256-14259
Two outstanding features of the flowering plant family Winteraceae are the occlusion of their stomatal pores by cutin plugs and the absence of water-conducting xylem vessels. An adaptive relationship between these two unusual features has been suggested whereby stomatal plugs restrict gas exchange to compensate for the presumed poor conductivity of their vesselless wood. This hypothesized connection fueled evolutionary arguments that the vesselless condition is ancestral in angiosperms. Here we show that in Drimys winteri, a tree common to wet forests, these stomatal occlusions pose only a small fixed resistance to water loss. In addition, they modify the humidity response of guard cells such that under high evaporative demand, leaves with plugs lose water at a faster rate than leaves from which the plugs have been experimentally removed. Instead of being adaptations for drought, we present evidence that these cuticular structures function to maintain photosynthetic activity under conditions of excess water on the leaf surface. Stomatal plugs decrease leaf wettability by preventing the formation of a continuous water film that would impede diffusion of CO2 into the leaf. Misting of leaves had no effect on photosynthetic rate of leaves with plugs, but resulted in a marked decrease (≈40%) in leaves from which the plugs had been removed. These findings do not support a functional association between stomatal plugs and hydraulic competence and provide a new perspective on debates surrounding the evolution of vessels in angiosperms. 相似文献
4.
Tamara T Perry Perla A Vargas Jeremy Bufford Charles Feild Michael Flick Pippa M Simpson Robert G Hamilton Stacie M Jones 《Annals of allergy, asthma & immunology》2008,100(4):358-363
BACKGROUND: The impact of preschool environmental conditions on classroom aeroallergen concentrations is not fully understood. OBJECTIVE: To examine the relationship between school environmental conditions and classroom aeroallergen concentrations in the Pulaski County Head Start (HS) Program. METHODS: Thirty-three HS centers in Pulaski County, Arkansas, underwent a detailed environmental evaluation. Classroom settled dust samples were analyzed for the presence of common indoor allergens. RESULTS: Classroom eating (70%), wall-to-wall carpeting (58%), and water damage (33%) were common. Median classroom allergen levels were as follows: dust mite (Der p 1 and Der f 1), 0.6 microg/g; Fel d 1, 0.4 microg/g; Can f 1, 1.7 microg/g; cockroach, below detection; Mus m 1, 0.18 microg/g; and mold spores, 17,800 CFU/g. Can f 1 and Mus m 1 allergens were detected in 100% of HS centers. Facilities with carpeting, increased humidity, and single-use facilities showed trends toward increased dust mite concentrations. Detectable cockroach allergen was more common in classrooms cleaned by teachers than by professional housekeepers. CONCLUSIONS: Aeroallergens were commonly detected in Pulaski County HS center classrooms, with dog and mouse allergens detected in 100% of centers. Median classroom allergen concentrations were low, and classroom characteristics were not strongly predictive of increased allergen exposure. 相似文献
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Effects of electroacupuncture on gastric mucosal blood flow and transmucosal potential difference in stress rats 总被引:9,自引:0,他引:9
EfectsofelectroacupunctureongastricmucosalbloodflowandtransmucosalpotentialdiferenceinstressratsXUGuanSun1,SUNYong1,WANGZhe... 相似文献
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目的:目前对后处理保护机制的研究还较孤立,缺乏上下游调节机制的联系.通过建立在体大鼠心肌缺血再灌注模型,探讨后处理在整体实验下的抗凋亡效应,以及这种心肌保护作用是否通过再灌注损伤救援激酶(reperfusion injury salvage kinase,RISK)信号转导通路来实现.方法:实验于2006-07/2007-05在首都医科大学病理生理学教研室完成.健康成年雄性SD大鼠32只,均分至以下4组:①心肌缺血再灌注组:结扎冠状动脉左前降支(缺血)45 min,再灌注4 h.②后处理组:在再灌注前,给予10s再灌、10s缺血,连续3个循环.③PI3K抑制剂组:在再灌注前5min经颈静脉注射磷脂酰激醇3激酶(PI3K)抑制剂LY-294002(0.3 mg/kg),余同③组.④MAPKK抑制剂组:在再灌注前5 min经颈静脉注射丝裂原激活蛋白激酶激酶(MAPKK)抑制剂PD 98059(0.3 mg/kg),余同②组.再灌注结束后取左室缺血区,使用Western blotting法检测各组心肌组织中凋亡指标Bax,Bcl-2,Caspase-3表达量变化及RISK通路中Akt,P-ERK 1/2及eNOS表达量变化.结果:32只大鼠均进入结果分析.与心肌缺血再灌注组相比,后处理组心肌凋亡显著减轻,Akt、P-ERK 1/2及eNOS含量显著升高;PI3K抑制剂组心肌凋亡较后处理组严重,Akt、eNOS含量降低;MAPKK抑制剂组心肌凋亡较后处理组严重,ERK 1/2含量降低.结论:后处理对再灌注心肌存在明显的抗凋亡作用,该作用可能与RISK信号转导通路的激活有关. 相似文献