Donor screening for antibody to hepatitis B core antigen and hepatitis B virus infection in transfusion recipients

BACKGROUND: Testing for antibody to hepatitis B core antigen (anti-HBc) as a surrogate for hepatitis C viremia is no longer needed for blood donor screening. Currently, the important question is how much its use supplements hepatitis B surface antigen (HBsAg) donor screening in preventing transfusion-transmitted hepatitis B virus (HBV) infection. STUDY DESIGN AND METHODS: In a study conducted in the 1970s, 64 blood donors were associated with 15 cases of HBV (1.0%) in 1533 transfusion recipients. Sera from 61 donors at donation and 29 follow-up visits were available for present-day assays for HBsAg, HBV DNA, anti-HBc, and antibody to HBsAg (anti-HBs). RESULTS: HBsAg was found in four previously negative blood donors; HBV DNA was limited to three of these four. Anti-HBc was detected in six HBsAg-negative donors. Two other donors were negative in all assays at donation, but positive for anti- HBc and anti-HBs 2 to 4 months later. The remaining donors were negative for all HBV markers, which left five recipient cases unexplained. No HBV transmission was observed when anti-HBs sample-to- negative control values were > or = 10. CONCLUSION: Some 33 to 50 percent of cases of hepatitis B that could be transmitted by transfusion of blood from HBsAg-negative donors are prevented by anti- HBc screening. Anti-HBc-positive donors unequivocally positive for anti- HBs should be considered noninfectious for HBV and should be allowed to donate. Anti-HBc screening of paid plasmapheresis donors, supplemented by anti-HBs testing, would reduce the amount of HBV to be processed by virus inactivation and increase the content of anti-HBs in plasma pools.     

经冠状动脉移植自体骨髓单个核细胞和间充质干细胞对急性心肌梗死模型心功能的改善

目的:为保护濒死心肌提供机会窗口,对比观察经冠脉移植自体骨髓单个核细胞或间充质干细胞后,实验性急性心肌梗死动物心功能变化及心肌组织核转录因子кB、心肌细胞凋亡情况。方法:实验于2005-03/2006-11在河北省人民医院实验中心完成。选用24只雄性冀中白猪,随机数字表法分为4组:正常对照组、模型组、单个核细胞组、间充质干细胞组,6只/组。①24只猪均以盐酸氯胺酮200mg臀部肌肉注射麻醉后,分别于各自右侧股骨抽取骨髓20mL,采用Fercoll法分离获得骨髓单个核细胞,加入胶体金溶液,培养12～16h待用。分离过程中取出含有骨髓单个核细胞成分的细胞层,常规培养传代,每3d换液1次,贴壁生长细胞即为骨髓间充质干细胞,加入胶体金溶液,培养24h待用。②除正常对照组外,其余各组均经导管球囊封闭第一对角支以远的前降支,复制猪急性心肌梗死模型。单个核细胞组、间充质干细胞组均于造模后立即开通前降支,分别经球囊注入预先分离的骨髓单个核细胞6×108个、间充质干细胞6×108个。模型组造模后于梗死1h开通前降支,经球囊注入磷酸盐缓冲液10mL。③各组分别于术前及术后4周经心脏超声检测心功能,取材行病理学检查、心肌组织核转录因子кB的免疫组织化学检测及心肌细胞凋亡检测。结果:24只雄性白猪均进入结果分析。①心功能变化:术前各组左心室收缩末内径、左心室舒张末内径、左心室射血分数、短轴缩短率基本相似。移植术后4周,正常对照组、单个核细胞组、间充质干细胞组左心室舒张末内径均明显低于模型组(F=4.68,P=0.01),左心室射血分数及短轴缩短率均明显高于模型组(F=5.14,P=0.01;F=3.32,P=0.04),各组左心室收缩末内径差异无显著性意义(F=1.64,P=0.21)。②心肌组织病理学改变:电镜下单个核细胞组、间充质干细胞组在梗死边缘区可见有胶体金颗粒的不成熟的心肌细胞,胞质中散在肌丝结构,肌丝排列紊乱不规则。③心肌组织核转录因子кB阳性率表达:与模型组比较,单个核细胞组、间充质干细胞组的梗死边缘区核转录因子кB阳性率明显降低(F=25.59,P=0.0001);正常心肌区核转录因子кB阳性率亦明显降低(F=18.20,P=0.0001)。④心肌细胞凋亡检测结果:与模型组比较,单个核细胞组、间充质干细胞组在心肌梗死区细胞凋亡率均明显降低(F=6.63,P=0.0027),梗死边缘区细胞凋亡率亦明显降低(F=36.07,P=0.0001)。正常心肌区单个核细胞组细胞凋亡率与模型组基本相似(F=9.69,P=0.004),但间充质干细胞组有所降低。⑤心功能与心肌细胞凋亡及心肌组织NF-кB的相关性:急性心肌梗死4周时,左心室射血分数与心肌细胞凋亡、心肌组织核转录因子кB均呈负相关(r=0.613,P=0.001;r=-0.437,P=0.033)。心肌细胞凋亡与心肌组织核转录因子кB呈正相关(r=0.672,P=0.002)。结论:经冠脉移植骨髓单个核细胞和间充质干细胞均可改善实验性急性心肌梗死动物的心功能,与梗死边缘区核转录因子кB表达降低及心肌细胞凋亡减少有关。骨髓单个核细胞移植的促血管增生作用优于间充质干细胞移植。     

构建以少突胶质细胞前体为主与人类早产儿脑室周围白质软化病理相似的动物模型

目的:建立以晚期少突胶质细胞前体为主、与人类早产儿脑室周围白质软化病理相似的可靠动物模型。方法:实验于2005-10/2006-06在上海交通大学医学院附属新华医院科研中心完成。2d龄和7d龄SD同窝清洁级新生大鼠各43只,雌雄不拘,以随机数字表法分为4组,即2d龄模型组(n=25)、2d龄假手术组(n=18)、7d龄模型组(n=25)和7d龄假手术组(n=18),脑室周围白质软化动物模型建立:结扎双侧颈总动脉,手术时间短于10～15min,术后将新生大鼠送入缺氧箱缺氧30min,混合气体为体积分数0.08的O2和0.92的N2,输入流量为1～2.5mL/min。假手术组游离双侧颈总动脉,但不予结扎和缺氧。将各组大鼠分别于术后1d测定脑梗死体积,术后2d进行少突胶质细胞系列免疫组织化学染色分析、脑片TTC染色观察脑梗死情况以及光镜下脑病理研究,术后21d进行电镜下病理研究。结果:实验86只新生大鼠,14只制作脑室周围白质软化模型死亡,余72只计入统计。①术后1d各组脑片大体观察:模型组脑内呈现大面积白色梗死区,多为大脑前、中动脉供血区域,2,7d龄模型组梗死体积分别为(53.45±33.90),(68.78±20.22)mm3,梗死百分比分别为(24.98±15.44)%,(11.84±4.14)%;假手术组脑片颜色鲜红,未见白色梗死区。②新生大鼠少突胶质细胞系列标志物免疫组织化学结果:2d龄新生大鼠脑白质内以少突胶质细胞前体为主,7d龄新生大鼠则以成熟少突胶质细胞为主。模型大鼠的相应少突胶质细胞系列阳性标记物的积分吸光度值均显著低于同日龄对照新生大鼠(P<0.05～0.01)。③各组大鼠术后2d光镜下脑病理检查结果:2d龄模型组新生大鼠的脑室周围以及皮层下白质呈现囊性坏死和细胞凋亡,而皮质神经元损伤轻微;而7d龄模型组在白质和皮质部位均呈明显损伤。④术后21d电镜下各组幼鼠脑病理检查结果:2d龄模型组幼鼠的脑白质内未见髓鞘形成,7d龄模型组幼鼠中见少量髓鞘形成,而同日龄假手术对照幼鼠的脑白质内则髓鞘形成正常。结论:通过对2d龄新生大鼠双侧颈总动脉结扎伴缺氧30min缺氧缺血法创建的脑室周围白质软化新生大鼠模型中存在少突胶质细胞前体和少突胶质细胞的明显受损和丢失,成功建立了2d龄新生大鼠以少突胶质细胞前体为主、与人类早产儿脑室周围白质软化病理相似的脑室周围白质软化动物模型。     

成纤维细胞生长因子2的分子结构和生物学效应

目的:成纤维细胞生长因子2是一种多功能、作用广泛的细胞因子。就成纤维细胞生长因子2分子结构和生物学效应以及与骨髓间充质干细胞移植治疗大鼠急性心肌梗死的相关研究进行综述。资料来源:应用计算机检索PubMed数据库1990-01/2006-10有关成纤维细胞生长因子2的文章,检索词“FGF-2,molecular structure,biological effect,myocardial infarction and rat and marrows tem cell”,限定文章语言种类为English。同时计算机检索中国期刊全文数据库、万方数据库1990-01/2006-10期间的相关文章,检索词“碱性成纤维细胞生长因子”,限定文章语言种类为中文。资料选择:对资料进行初审,选取符合研究要求的有关文章找全文。纳入标准:①有关成纤维细胞生长因子2分子结构、生物学特性的研究。②有关骨髓间充质干细胞移植治疗急性心肌梗死的研究。资料提炼:共收集到34篇有关成纤维细胞生长因子2分子结构和生物学效应的文章,67篇有关骨髓间充质干细胞移植治疗大鼠急性心肌梗死的研究。选取其中31篇归纳总结。资料综合:①成纤维细胞生长因子2在人体内普遍存在,许多体外培养的细胞也自分泌成纤维细胞生长因子2。成纤维细胞生长因子2包括18000的低相对分子质量成纤维细胞生长因子2和高相对分子质量成纤维细胞生长因子2。成纤维细胞生长因子2翻译的起始密码子有两种:AUG和CUG。②成纤维细胞生长因子2有两种不同的受体,它们可与相应的受体结合发挥生物学功能。③在体外培养骨髓间充质干细胞的过程中,成纤维细胞生长因子2可促进其向心肌样细胞分化,在相对缺氧的环境下,提高心肌样细胞存活率。结论:成纤维细胞生长因子2作为一种多功能的细胞生长因子,在胚胎发育,创伤修复以及缺血、炎症、肿瘤等情况下,可作用于靶细胞上的特异性受体,发挥多种生理功能。它对新生血管形成过程中的毛细血管基底膜降解、内皮细胞迁移增殖、胶原合成及小血管腔形成等均有明显的促进作用。在相对缺氧的环境下,成纤维细胞生长因子2提高心肌样细胞存活率。     

贞芪扶正颗粒和复方阿胶浆干预再生障碍性贫血模型小鼠外周血及骨髓象的变化

目的:观察贞芪扶正颗粒和复方阿胶浆对苯油溶液致小鼠再生障碍性贫血模型的疗效。方法:实验于2005-06/09在河南中医学院药理实验室完成。①选用昆明种成年雄性小鼠90只。按随机数字表法将小鼠分为9组,每组10只:大、中、小剂量贞芪扶正颗粒组:按15,10,5g/kg剂量灌服贞芪扶正颗粒混悬液(主要成分:黄芪、女贞子;甘肃扶正药业科技股份有限公司生产;批号040803,15g/袋)。大、中、小剂量复方阿胶浆组:分别按10,20,30mL/kg剂量灌胃复方阿胶浆(主要成分:阿胶、熟地黄、党参、山楂、人参、蔗糖;山东东阿阿胶股份有限公司生产,批号050446,250mL/瓶),司坦唑醇组:按4mg/kg剂量灌胃司坦唑醇混悬液(司坦唑醇片,广西南宁百会药业集团有限公司生产,批号050306,30mg/片)。空白组和模型组:灌胃同体积的生理盐水(20mL/kg)。每天给药1次,连续给药14d。除空白组外,其余组小鼠皮下注射体积分数0.25苯的玉米油溶液4mL/kg复制苯油溶液致小鼠再生障碍性贫血模型,空白组皮下注射同体积玉米油。②各组小鼠分别于末次给药后24h,进行血常规检测。取右侧股骨,冲出骨髓细胞,采用BI-2000医学图像分析仪计数骨髓有核细胞数。③计量资料符合正态分布、方差齐者用t检验;方差不齐者用t’检验。结果:小鼠90只均进入结果分析。①血细胞测定结果比较:模型组小鼠血红细胞、白细胞、血小板计数和血红蛋白水平明显低于空白组(t=3.39～11.89,P<0.01)。司坦唑醇组3项血细胞计数和血红蛋白水平明显高于模型组(t=4.94～6.73,P<0.01)。大、中剂量贞芪扶正颗粒组和各剂量复方阿胶浆组血白细胞计数明显高于模型组(t=2.32～3.03,P<0.05￣0.01)。中剂量贞芪扶正颗粒组和各剂量复方阿胶浆组小鼠血红细胞计数明显高于模型组(t=2.15～4.84,P<0.05￣0.01)。大、中剂量贞芪扶正颗粒组和各剂量复方阿胶浆组血红蛋白水平明显高于模型组(t=2.33～4.45,P<0.05￣0.01)。大、中剂量贞芪扶正颗粒组和各剂量复方阿胶浆组血小板计数明显高于模型组(t=4.06～6.24,P<0.01)。②骨髓有核细胞数:模型组明显低于空白组(t=8.99,P<0.01)。司坦唑醇组、中剂量贞芪扶正颗粒组和小剂量复方阿胶浆组明显高于模型组(t=2.39～2.82,P<0.05)。结论:贞芪扶正颗粒、复方阿胶浆对皮下注射苯所致小鼠再生障碍性贫血模型血细胞状况及骨髓象均有较好的改善作用,以贞芪扶正颗粒有较为明显的剂量依赖关系。     

Donor levels of serum alanine aminotransferase activity and antibody to hepatitis B core antigen associated with recipient hepatitis C and non- B, non-C outcomes

BACKGROUND: Hepatitis virus(es) that are neither hepatitis B (HBV) nor hepatitis C (HCV) (non-B, non-C [NBNC]) may be transmitted by transfusion. The present study assessed donor values for alanine aminotransferase (ALT) and antibody to hepatitis B core antigen (anti- HBc) for their association with HCV and NBNC hepatitis outcomes among allogeneic blood recipients. STUDY DESIGN AND METHODS: Data on blood donors and recipients enrolled in the Transfusion- Transmitted Viruses Study in four United States cities from 1974 through 1980 were supplemented by anti-HBc testing of donors and anti-HCV evaluation of recipients. Two statistical approaches estimated the value of these indirect tests in detecting donors associated with HCV seroconversion and NBNC hepatitis in recipients. RESULTS: For HCV cases, donor ALT alone (at > or = 60 IU/L) had a sensitivity and a specificity of 30 and 96 percent, respectively, and anti-HBc alone (at > or = 60% inhibition) had a sensitivity and specificity of 53 and 86 percent, respectively. The two markers combined had a sensitivity and a specificity of 69 and 83 percent. For NBNC hepatitis cases, each measure had low sensitivity (20%) that was not improved by using both (28%) [corrected]. CONCLUSION: The indirect tests proved to be equal in sensitivity to the first-generation anti-HCV tests. The positive predictive power of these indirect tests in the 1980s was sufficient to affect HCV incidence in studies during that period. Improved anti-HCV assays, however, replaced the need for indirect tests. The sensitivity of indirect tests for NBNC hepatitis contributed little.     

Entry screening to delay local transmission of 2009 pandemic influenza A (H1N1)

Background  

After the WHO issued the global alert for 2009 pandemic influenza A (H1N1), many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission.     

Redistribution of joint moments is associated with changed plantar pressure in diabetic polyneuropathy

Background  

Patients with diabetic polyneuropathy (DPN) are often confronted with ulceration of foot soles. Increased plantar pressure under the forefoot has been identified as a major risk factor for ulceration. This study sets out to test the hypothesis that changes in gait characteristics induced by DPN related muscle weakness are the origin of the elevated plantar pressures.     

Evolution of chemical-specific adjustment factors (CSAF) based on recent international experience; increasing utility and facilitating regulatory acceptance

The application of chemical-specific toxicokinetic or toxicodynamic data to address interspecies differences and human variability in the quantification of hazard has potential to reduce uncertainty and better characterize variability compared with the use of traditional default or categorically-based uncertainty factors. The present review summarizes the state-of-the-science since the introduction of the World Health Organization/International Programme on Chemical Safety (WHO/IPCS) guidance on chemical-specific adjustment factors (CSAF) in 2005 and the availability of recent applicable guidance including the WHO/IPCS guidance on physiologically-based pharmacokinetic (PBPK) modeling in 2010 as well as the U.S. EPA guidance on data-derived extrapolation factors in 2014. A summary of lessons learned from an analysis of more than 100 case studies from global regulators or published literature illustrates the utility and evolution of CSAF in regulatory decisions. Challenges in CSAF development related to the adequacy of, or confidence in, the supporting data, including verification or validation of PBPK models. The analysis also identified issues related to adequacy of CSAF documentation, such as inconsistent terminology and often limited and/or inconsistent reporting, of both supporting data and/or risk assessment context. Based on this analysis, recommendations for standardized terminology, documentation and relevant interdisciplinary research and engagement are included to facilitate the continuing evolution of CSAF development and guidance.