新生大鼠腰交感神经节凋亡细胞的电镜观察

目的 :观察出生后早期大鼠腰交感神经节细胞凋亡超微结构变化特点。方法 :大鼠按出生后 1d、1w、2w和3w分组 ,取L3、L4交感神经节常规超薄切片 ,铅轴染色 ,透射电镜观察。结果 :1d 2w组腰交感神经节内可见到明显的神经节神经细胞胞体凋亡和突起的退变 ,同时可观察到包绕上述突起的雪旺细胞也发生凋亡。早期凋亡细胞的超微结构特点为核染色质在核膜下的凝集。结论 :出生后早期部分腰交感神经节神经细胞因未能与其靶区建立联系而凋亡 ,随后包绕凋亡神经细胞突起的雪旺细胞也发生凋亡。     

Allergic characteristics of urban schoolchildren with atopic eczema in Ghana

Background Atopic eczema is an increasing clinical problem in Africa. Objective To determine allergic characteristics and to identify possible risk factors for eczema among schoolchildren in an urbanized area in Ghana. Patients and methods Schoolchildren aged 3–16 years with eczema were recruited. For each patient, one to three age‐ and sex‐matched controls were selected. All children completed a questionnaire and were skin prick tested with a panel of allergens. Blood was drawn to determine the total and allergen‐specific IgE. Conditional logistic regression models with the matching factors included in the model were used to calculate the odds ratios and to adjust for possible confounders. Results A total of 52 children with eczema (27 boys and 25 girls) and 99 controls were included. Levels of total IgE were found to be 9.1 (1.1; 78.4) times more often elevated in children with eczema. This association was mainly driven by elevated IgE levels against cockroach antigen. Children with eczema were found to have 2.0 (0.87; 4.7) times more often positive skin prick tests (SPT), but this association diminished to 1.2 (0.40; 3.6) after adjustment for total IgE levels. Frequent washing with soap was identified as a risk factor for the development of eczema among these children. Conclusion Schoolchildren with eczema in Ghana were characterized by elevated IgE levels especially against cockroach antigen. The association between eczema and positive SPT was much weaker suggesting immune hyporesponsiveness of the skin. After adjustment for IgE level, SPT were less suitable to distinguish children with and without eczema.