Size effect on systemic and mucosal immune responses induced by oral administration of biodegradable microspheres

Induction of systemic and mucosal immune responses following oral administration of biodegradable poly( -lactic acid) (PDLLA) microspheres containing a model antigen, ovalbumin (OVA) was studied using microspheres with different average diameters of 0.6, 1.0, 4.0, 7.0, 11.0, 15.0, 21.0, and 26.0 μm. They were prepared from double emulsion with the solvent evaporation method, followed by size fractionation on counterflow elutriation. OVA was released from the microspheres in vitro over 80 days, irrespective of their size. Production of the serum anti-OVA IgG antibody and secretory OVA-specific IgA antibody in the mice gut was assessed following the oral administration of PDLLA microspheres containing OVA. Microspheres with a diameter of 4.0 μm enhanced the serum antibody in contrast with that of free OVA, but were not effective in inducing the gut secretion of IgA antibody. On the other hand, OVA-containing microspheres with a diameter of 7.0 μm enhanced IgA secretion to a significant extent compared with free OVA, whereas those with 26.0 μm in diameter were ineffective. Body distribution study revealed that the amount of microspheres taken up into Peyer's patches (PP) increased with the increasing size up to 11.0 μm, thereafter decreased, and finally became zero when their diameters were 21.0 μm or larger. The microspheres taken up into PP were translocated to the spleen, but no microspheres were noticed in the spleen when the size was larger than 5 μm. After being taken up into PP, microspheres <5 μm in diameter seemed to be transported to the spleen, a systemic lymphoid tissue, where the released antigen stimulated a serum antibody response, but larger microspheres probably remained at PP without being tanslocated to the spleen over the course of their antigen release, leading to induction of IgA secretion. It was concluded that the body distribution pattern of microspheres following the PP uptake was a key factor to regulate the induction of systemic and mucosal immune responses.     

2007年广州部分大学生乙肝疫苗接种与乙肝相关知识态度调查

目的了解大学生乙肝疫苗(HBV)接种情况和大学生对乙型肝炎的认知程度,为制定更好的免疫接种计划提供更为可靠的依据。方法2007年,在广州市抽取4所高等学校的部分大学生进行调查。结果调查191人,HBV接种率为76.44%,其中全程接种的为64.92%。HBV接种率及全程接种率,不同年龄学生间有显著性差异(P<0.05),不同家庭经济收入的学生有差异(P<0.05)。有乙肝疫苗接种史者、全程接种者对乙肝是否经日常生活接触传播的知晓率仅为56.16%、60.48%,经唾液传播的知晓率仅为41.78%、45.16%;97.4%的被调查者表示会劝亲人或朋友去接种乙肝疫苗,93.7%的被调查者表示会愿意接受乙肝病人或乙肝携带者赠送的礼物。20.9%的被调查者表示会回避与乙肝病人或乙肝携带者交往,同时86.9%的被调查者也表示不介意与乙肝携带者一起工作或学习。结论广州市大学生HBV接种率较高,对乙肝知识的知晓率较高,对乙肝病人多有正确的态度,但在某些方面存在误区。     

短程免疫法制备抗血清效果比较

目的探讨快速制备抗血清的方法和效果,以适应其在实验教学中的需要。方法采用短程免疫法,对家兔分组,用大肠杆菌抗原菌液、绵羊红细胞(SRBC)抗原和鸡蛋黄抗原小剂量连续多次接种后,收集抗血清,对其效价进行测定,并与传统抗血清制备方法进行比较。结果经大肠杆菌抗原、绵羊红细胞(SRBC)抗原和鸡蛋黄抗原免疫后的抗血清最终分别达到1∶10240、1∶1200和1∶10240的高效价。结论此方案制备抗血清所用时间短,效价高,亲和力强,适用于实验教学。     

2005年大连市常规免疫接种率报告与监测评价

[目的]了解大连市常规免疫接种率监测情况.[方法]采用差值(D) 和比值(R)评价方法对大连市2005年常规免疫接种率进行统计分析.[结果]县(市、区,下同) 级报告的及时率和完整性分别96.97%、100.00%.2005年卡介苗、脊髓灰质炎疫苗、百白破联合疫苗、麻疹疫苗、乙型肝炎疫苗的常规免疫报告接种率均在99.00%以上,而估计接种率与报告接种率相差较大.口服脊髓灰质炎疫苗、百白破联合疫苗、麻疹疫苗D值不可信,卡介苗和乙型肝炎疫苗均为可疑.[结论]大连市常规免疫监测数据偏高.应加强技术培训,提高报告接种率的可信性.     

1991～2006年乐山市甲型肝炎流行特征分析

[目的]探讨乐山市甲肝流行特征,为政府制订防治对策提供科学依据.[方法]采用描述流行病学方法分析甲型肝炎的三间分布情况.[结果]1999～2006年与1991～1998年比较发病率下降了77.07%,死亡卒下降了88.80%,发病年龄呈后移趋势(χ2=642.86,P＜0.000),儿童学生发病构成呈下降趋势,工人、农民等发病构成呈上升趋势(χ2=323.068,P＜0.000),前期发病率居前5位的均为丘陵区县、后期居前5位的为山区或深丘区县.[结论]甲肝是可以通过免疫控制甚至消灭的传染病,但是国家尚未纳入计划免疫管理,接种率得不到应有的保护水平,将甲肝疫苗纳入免疫规划并免费接种,长期坚持消灭甲肝就可能成为现实.     

通辽市2007年常规免疫接种率监测系统运转情况

目的分析评价全市计划免疫接种率监测系统运转情况，探讨改善监测工作。方法采用《全国常规免疫接种率监测方案》规定的接种率评价方法，对报告及时性、完整性、报告接种率、估算接种率、差值（D）、比值（R）进行评价。结果全市及各旗县的基础免疫及加强免疫报告接种率均在99％以上。全市基础免疫估算接种率为71．33％～101．16％。D值评价，基础免疫BCG、OPV、DPT、MV和HB—VAX的报告接种率全市除BCG和HB-VAX均为可信，8个旗（县、市、区）中绝大多数为可信；全市R1=0．84，R2=0．84，R3=1．19，R6=1．37，均为不可信；R4=0．96，R5=0．97，为可信。结论全市基础免疫报告接种率维持在较高水平，但应种人数掌握不准。     

潍坊市2006年常规免疫接种率监测结果分析

目的了解潍坊市常规免疫接种率监测现状，促进接种工作的改善。方法利用2006年的监测资料，采用差值（D）评价和比值（R）评价方法进行比较分析。结果该市12个县（市、区）级报告的及时率为91．07％，完整率、准确率均为100％，数据完整率为92．86％。卡介苗、口服脊髓灰质炎疫苗、百白破混合制剂、麻疹疫苗、乙肝疫苗的常规免疫报告接种率为97．51％-100％，估算接种率为86．52％～128．87％，与报告接种率之间还有差距。D值显示，5个县的资料为可信，6个县可疑，1个县为不可信。结论计划免疫工作各县间发展不平衡，主要与流动儿童的计划免疫管理不完善和部分市工作薄弱有关。     

Staff awareness of oral polio vaccine vial monitor in Chandigarh

This study highlights the awareness of pulse polio centre staff about polio vaccine vial monitor (VVM) during a National Immunization Day in Chandigarh. Out of the 79 staff members interviewed, only 53 (67%) had ever heard of the VVM and were further interviewed. Fifty (94.4%) staff members were aware that VVM is present on vaccine itself and majority (79.2%) told that it is the inner square with outer circle. Only half were aware of its function and 71.7% knew how to read it. It was observed that awareness among health staff [Health worker (F)/ANM] and volunteers was very poor. There is a need for effective training of staff before subsequent PPI to maintain an effective cold chain.     

Routine hepatitis B immunisation in India: Cost-effectiveness assessment

Based on World Bank guidelines, hepatitis B immunization would be an excellent public health investment, saving each life year for well below the per-capita gross domestic product. This would be one of the most cost-effective investments india could make in the field of health.     

pCXN2-mIZUMO对C57BL/6小鼠生育能力的影响

背景与目的:精卵融合是发生在受精过程中的重要生物学事件,Izumo是位于顶体内膜上的I型免疫球蛋白,是一种具有精子特异性的膜蛋白,在精卵融合中起关键作用.我们研究pCXN2-mIZUMO在小鼠C57BL/6肌肉中的表达及对其生育能力的影响,为进一步研究免疫避孕手段提供实验依据.材料与方法:用重组质粒pCXN2-mIZUMO分别免疫雌和雄性C57BL/6小鼠.ELISA测定小鼠体内的抗Izumo抗体水平,检测小鼠抗血清在体外受精中对受精率的影响,被免疫的雌性、雄鼠分别与正常的雄、雌鼠交配,雌雄合笼比例为2:1,分娩完成后统计其产仔数.结果:pCXN2-mIZUMO可以在小鼠体内诱发抗Izumo特异性免疫应答.被pCXN2-mIZUMO免疫后的小鼠抗血清在体外能够降低其受精率;各组产仔数分别为:实验雌鼠组2.9±0.66;对照雌鼠组5.4±0.82;实验雄鼠组5.1±0.99;对照雄鼠组6.0±1.34.实验雌鼠组的生育能力比对照雌鼠组明显降低(P＜0.05).结论:重组质粒pCXN2-mIZUMO免疫雌性小鼠具有降低生育能力的作用.