Optimizing immunization in pediatric special risk groups

This article analyzes the current recommended practices and evidence in the immunization of pediatric 'special risk groups'. Special risk group patients are at higher risk of vaccine-preventable diseases and hence require additional strategies to maximize protection against these diseases. The special risk groups include those with an underlying chronic disease, some of whom are on immunosuppressive therapy to treat that condition. The article uses four special risk groups (acute lymphoblastic leukemia; preterm birth; juvenile idiopathic arthritis; and inflammatory bowel disease), to highlight the management considerations and potential vaccination strategies. The risks, benefits and timing of vaccination in the setting of immunosuppression require detailed discussion with treating clinicians, in particular the use of live-attenuated vaccines. The immunogenicity of vaccines in these special risk groups helps provide the evidence base for their immunization guidelines. Protection can include 'cocooning' (i.e., ensuring appropriate immunizations within the immediate family; e.g., varicella, influenza and pertussis vaccination). Improving timeliness and minimizing missed opportunities to vaccinate individuals with these special risk conditions will also optimize protection from vaccine-preventable diseases.     

黄芪多糖对人心脏微血管内皮细胞增殖及再灌注后内皮细胞与中性粒细胞黏附的影响

目的:观察黄芪多糖对人心脏微血管内皮细胞的增殖效应及其对再灌注损伤人心脏微血管内皮细胞与人外周血中性粒细胞黏附作用的影响。方法:实验于2006-07/12在北京中医药大学东直门医院中医内科重点实验室完成。①实验材料:原代人心脏微血管内皮细胞(ScienCell公司);黄芪多糖(惠州市东方植物保健科技有限公司)。②实验过程及评估:实验使用体外培养的人心脏微血管内皮细胞第4,5代细胞,采用倒置相差显微镜下观察细胞形态和生长情况;以四甲基偶氮唑盐法检测经不同浓度黄芪多糖处理24h,以及经黄芪多糖100,50,25mg/L分别处理4,6,8h后的增殖变化;以体外缺糖缺氧2h模拟体内缺血,复糖复氧6h模拟再灌注复制人心脏微血管内皮细胞再灌注损伤模型;虎红法测定经缺氧再复氧处理后的人心脏微血管内皮细胞与外周血中性粒细胞的黏附;免疫细胞化学法和图象定量分析系统观察细胞间黏附分子1的蛋白表达变化。结果:①人心脏微血管内皮细胞形态和生长情况:人心脏微血管内皮细胞复苏48～72h后细胞呈铺路石样生长,在15个细胞倍增周期内,其形态、生物、生理学特性稳定。②不同浓度黄芪多糖对人心脏微血管内皮细胞增殖的影响:黄芪多糖浓度≥5g/L时,对细胞生长具有抑制作用(P<0.05或0.01);浓度为2.5g/L时,对细胞的增殖无影响;浓度在1.25g/L～18.78mg/L时,可明显促进细胞的增殖(P<0.05或0.01)。③黄芪多糖处理不同时间对人心脏微血管内皮细胞增殖的影响:经黄芪多糖100,50,25mg/L3个剂量分别处理4,6,8h后,其增殖与正常对照组比无明显变化。④黄芪多糖对人心脏微血管内皮细胞与中性粒细胞间黏附作用及人心脏微血管内皮细胞细胞间黏附分子1蛋白表达的影响:黄芪多糖50mg/L可显著抑制再灌注损伤人心脏微血管内皮细胞与外周血中性粒细胞的黏附(P<0.01);100mg/L可明显降低人心脏微血管内皮细胞的细胞间黏附分子1蛋白表达(P<0.05)。结论:①黄芪多糖在一定浓度范围内可促进人心脏微血管内皮细胞的增殖,但需较长的作用时间才能发挥促增殖效应。②黄芪多糖对缺血再灌注损伤人心脏微血管内皮细胞具有保护作用,其作用机制可能与促进再灌注损伤人心脏微血管内皮细胞增殖修复,降低人心脏微血管内皮细胞表面细胞间黏附分子1蛋白表达,进而抑制与外周血中性粒细胞的黏附有关。