恙螨RAPD－PCR初步研究

通过制备恙螨的基因组ＤＮＡ，利用一组１０个碱基序列的单链随机引物，建立恙螨的随机引物ＤＮＡ多态性分析技术（ＲＡＰＤ－ＰＣＲ），为恙螨的种间、种内、种下、种群之间的分子分类、遗传特性、亲缘关系等研究打基础。本研究筛选出Ｎ０１，Ｎ０５，Ｎ０８，Ｎ１０４个随机引物，较适的缓冲液ｐＨ值，Ｍｇ￣（２＋）浓度和模板ＤＮＡ浓度，以及ＰＣＲ实验参数。     

2536只小兽体表革螨种类记述

为了解小兽体表革螨的种类概况，本文在对云南西部12个县（市）室内及室外农耕地生境分层抽样调查的基础上，对境内捕获的2536只小兽体表的5924只革螨进行了分类鉴定。全部革螨隶属9科58种，其中包括11个优势种、9个新种、1个国内新纪录及多种能传播流行性出血热等疾病的媒介革螨，多数种类寄居于两种以上的小兽宿主。结果表明，云南西部小兽体表革螨种类丰富，新种较多，部分螨种宿主持异性低，与医学关系密切。     

Bronchial responsiveness to methacholine is increased in citrus red mite (Panonychus citri)-sensitive children without asthmatic symptoms

BACKGROUND: A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is a common sensitizing allergen among children living around citrus farms. OBJECTIVE: A cross-sectional survey was performed to evaluate the bronchial responsiveness to methacholine in CRM-sensitive children without asthmatic symptoms. SUBJECTS AND METHODS: A total of 375 children living around citrus farms were enrolled in this study. There were 201 boys and 174 girls with a mean age of 12.5 (range 7-16) years. Each subject was evaluated by a questionnaire, a skin prick test with 13 common inhalant allergens including CRM, and a methacholine bronchial provocation test (MBPT). RESULTS: Positive rate of MBPT (PC20-methacholine < 25 mg/mL) was higher in atopic rhinitic and atopic control children than in nonatopic rhinitic and nonatopic control subjects (41.3% and 33.3% vs 17.2% and 15.4%, respectively, both P < 0.05). Slope of dose-response curve (DRS, %/mg/mL) was higher in atopic rhinitic children than in nonatopic rhinitic, atopic control and nonatopic control subjects (14.3 +/- 0.87 vs 9.4 +/- 0.72, 10.0 +/- 1.37 and 9.2 +/- 1.51, P < 0.05, respectively). Both the positive rate of MBPT and the DRS were increased in children with positive skin response to CRM than in those without sensitization (48.2% vs 22.9%, P = 0.0001; 15.6 +/- 1.26 vs 10.2 +/- 0.65, P = 0.0001). CONCLUSION: Bronchial responsiveness is increased in citrus red mite-sensitive children even if they have no asthmatic symptoms.     

Ozone and allergen exposure during postnatal development alters the frequency and airway distribution of CD25+ cells in infant rhesus monkeys

The epidemiologic link between air pollutant exposure and asthma has been supported by experimental findings, but the mechanisms are not understood. In this study, we evaluated the impact of combined ozone and house dust mite (HDM) exposure on the immunophenotype of peripheral blood and airway lymphocytes from rhesus macaque monkeys during the postnatal period of development. Starting at 30 days of age, monkeys were exposed to 11 cycles of filtered air, ozone, HDM aerosol, or ozone + HDM aerosol. Each cycle consisted of ozone delivered at 0.5 ppm for 5 days (8 h/day), followed by 9 days of filtered air; animals received HDM aerosol during the last 3 days of each ozone exposure period. Between 2-3 months of age, animals co-exposed to ozone + HDM exhibited a decline in total circulating leukocyte numbers and increased total circulating lymphocyte frequency. At 3 months of age, blood CD4+/CD25+ lymphocytes were increased with ozone + HDM. At 6 months of age, CD4+/CD25+ and CD8+/CD25+ lymphocyte populations increased in both blood and lavage of ozone + HDM animals. Overall volume of CD25+ cells within airway mucosa increased with HDM exposure. Ozone did not have an additive effect on volume of mucosal CD25+ cells in HDM-exposed animals, but did alter the anatomical distribution of this cell type throughout the proximal and distal airways. We conclude that a window of postnatal development is sensitive to air pollutant and allergen exposure, resulting in immunomodulation of peripheral blood and airway lymphocyte frequency and trafficking.