Platelet adhesion to fibronectin in flow: the importance of von Willebrand factor and glycoprotein Ib

We describe glycoprotein (GP) Ib as a mediator of adhesion to fibronectin, specifically in flow. A monoclonal antibody (MoAb) directed to the von Willebrand factor (vWF)-binding site on this receptor or the absence of this receptor on the platelet membrane, in the case of a patient with the Bernard-Soulier syndrome, reduced platelet coverage to fibronectin to approximately 30% of the control value. A MoAb directed to the GP Ib-binding site on vWF showed a similar effect. With washed platelets in the absence of plasma vWF, the inhibitory effect of the anti-GP Ib antibody was the same as with whole blood. No inhibition with the anti-GP Ib antibody was observed when we used blood from patients with severe von Willebrand disease (vWD) or from a patient with vWD type I (platelet low). Addition of vWF to vWD blood resulted in restoration of adhesion. Immunoelectron microscopy on platelets adhering to fibronectin showed that GP Ib was homogeneously distributed over the entire surface of the platelet. vWF was present at the central zone and the edges of the platelet and at the basal interface between the platelet and the fibronectin surface. No direct binding of vWF to fibronectin could be demonstrated. These data indicate that GP Ib-mediated adhesion to fibronectin fully depends on vWF and that normal levels of plasma or platelet vWF are sufficient for optimal adhesion to fibronectin. The data suggest that the presence of platelets during perfusion is a prerequisite for vWF to support platelet adhesion to fibronectin.     

Paroxysmal nocturnal hemoglobinuria and the transfusion of washed red cells. A myth revisited

Paroxysmal nocturnal hemoglobinuria (PNH) is an uncommon, acquired clonal stem cell disorder primarily affecting red cells that have an abnormal sensitivity to complement lysis. Since 1948, the use of saline-washed red cells (WRBCs) has been advocated to minimize hemolysis after transfusion to patients with PNH. Thirty-eight years of experience (1950 through 1987) with patients who had PNH were reviewed. Twenty-three patients with a positive Ham's test had been transfused with 556 blood components, including 431 RBC products: 94 units of whole blood, 208 units of packed RBCs, 80 units of white cell-poor RBCs, 38 units of WRBCs, 5 units of frozen RBCs, and 6 units of intraoperatively salvaged RBCs. Only one documented episode of posttransfusion hemolysis related to the underlying diagnosis of PNH was found, and it was associated with the transfusion of a unit of type O whole blood to an AB-positive individual. This unit contained ABO-incompatible plasma; this case was similar to one in an earlier report from which originated the recommendation for using WRBCs. The posttransfusion increment in hemoglobin concentration in patients receiving ABO-identical packed RBCs was comparable to that in patients receiving frozen or washed RBCs. These findings indicate that the use of WRBCs is unnecessary and that patients with PNH should be transfused with group-specific blood and blood products.     

粗大运动功能测试量表与Gesell发育量表在脑性瘫痪疗效评估中的应用比较

目的:比较粗大运动功能测试量表及Gesell发育量表在脑性瘫痪康复疗效评估中的应用效果。方法:选择2005-05/12在山东大学齐鲁儿童医院康复中心初次接受康复治疗的脑性瘫痪患儿25例,符合2004年全国小儿脑性瘫痪研讨会制定的诊断标准(金标准),监护人均知情同意。脑性瘫痪患儿均采用综合康复治疗:①Vojet法。②Bobath法。③推拿。④针灸,每次留针1h。每周连续治疗6d,休息1d,持续治疗3个月为1个疗程。所有患儿在接受康复治疗前及治疗1个疗程后均进行粗大运动功能测试量表和Gesell发育量表粗大运动发育龄、发育商评估。①粗大运动功能测试量表:总分100分表明患儿能完全完成该量表的全部内容,0分表明患儿不能完成该量表的最低运动评估项目。总分百分比为5个能区原始分占各自总分百分比之和再除以5。②Gesell发育量表:发育龄=∑(M×n)÷∑n(M代表测查取的月龄,n代表测查通过的项目,∑为若干数据的总和);发育商为测得的发育年龄与实际年龄的百分比。大运动发育商数55～75为轻度障碍,40～54为中度障碍,25～39为重度障碍,<25为极重度障碍。结果:25例患儿全部进入结果分析,无脱落。①治疗前及治疗1个疗程后患儿的量表评分比较:康复治疗进行1个疗程后患儿的粗大运动功能测试量表总分百分比及Gesell粗大运动发育龄显著高于治疗前[(22.64±4.18)%,(11.92±3.42)个月;(16.96±4.50)%,(10.18±3.48)个月(t=28.74,16.44,P<0.01)],而发育商显著低于治疗前(50.05±8.04,51.12±8.20,t=11.85,P<0.01)。②两个量表的敏感性比较:粗大运动功能测试量表总分百分比治疗后提高百分比为(6.46±5.65)%,Gesell发育量表粗大运动发育龄治疗后提高百分比为(1.28±1.29)%,两者之间差异具有显著性意义(P<0.01)。结论:Gesell发育量表在脑性瘫痪康复疗效评估中有一定的局限性,粗大运动功能测试量表可用于脑性瘫痪康复疗效的评估,而且对康复训练也能起到指导意义。     

不同分离方法对鼠胚胎成纤维细胞生长影响的比较

目的:采用组织块培养法、单细胞悬液法、滤网过滤改良法分离培养鼠胚胎成纤维细胞,比较不同分离方法对其生长形态、生长曲线及细胞周期的影响。方法:实验于2006-03/09在辽宁医学院解剖实验室完成。①选取清洁级昆明种七八周龄雄性小鼠10只,4周龄雌性小鼠20只,雄雌鼠按1∶2合笼,次日晨检查有阴栓者记为孕0.5d,选择孕12.5～14.5d雌鼠断颈处死,取出胎鼠,去除胚胎头部、内脏和四肢,将躯干部用无菌眼科剪剪成1mm3以下的碎块,分别用以下方法进行分离培养。②组织块培养法:将剪碎的组织块吸置于离心管内,加入1mL消化液(含2.5g/L胰蛋白酶和0.4g/L乙二胺四乙酸的磷酸盐缓冲液),吹吸30s,加入等体积的完全培养基(含体积分数为0.1的胎牛血清)终止消化,弃上清液,留下鼠胚组织块沉淀物,按相互距离0.5cm放入培养瓶内,培养箱静置2～4h后,加入适量完全培养基,3d换液一次。③单细胞悬液法:将剪碎的组织块加入1mL消化液,吹打30s,室温下静置3～5min,吸取上层液体,再加入消化液,重复上述操作五六次,最后弃组织块,将收集的上层液离心,1000r/min离心5min,弃上清液,加入完全培养基5mL,吹打均匀后吸至培养瓶内培养。培养条件、换液时间与组织块培养法相同。④滤网过滤改良法:将剪碎的组织块加入1mL消化液,吹打30s,37℃水溶箱中轻摇3～5min,加入完全培养基1mL终止消化,室温下静置1.0～2.0min,用直径5cm、孔径为150目滤网过滤后,将过滤液以1000r/min离心5min;弃上清液,加入适量完全培养基,轻吹30～50下,吸至培养瓶内,37℃、体积分数为0.05的CO2孵箱中培养24h,半量换液,以后3d换液一次。⑤检测不同分离方法对鼠胚胎成纤维细胞生长形态、生长曲线及细胞周期的影响。结果:①鼠胚胎成纤维细胞生长形态观察:组织块培养法第2天可见少量成纤维细胞,细胞生长缓慢,需要七八天才能传代。单细胞悬液法第2天可见成纤维细胞生长,细胞量虽多,但死亡的细胞也较多,细胞活力减弱,四五天后传代。滤网过滤改良法第2天可见成纤维细胞呈长梭形,胞浆饱满,细胞生长迅速,三四天长满培养瓶,三四天传代。②细胞生长曲线检测:组织块培养法培养的细胞第4～8天进入对数生长期,单细胞悬液法培养的细胞第3～5天进入对数生长期,滤网过滤改良法培养的细胞第2～4天进入对数生长期。③细胞周期检测与增殖指数:培养第3天,滤网过滤改良法所得的鼠胚胎成纤维细胞增殖指数最高,达到54.12%,单细胞悬液法、组织块培养法细胞增殖指数分别为53.52%和53.15%,3种方法差异无显著性意义(P>0.05),表明其细胞周期基本相同。结论:滤网过滤改良法可以在较短时间内培养出优质高采的鼠胚胎成纤维细胞。     

Epidemiology of blood transfusion

BACKGROUND: Earlier investigations of the epidemiologic attributes of blood transfusion were not based on total community populations. To calculate incidence rates of the transfusion of blood and blood components in the general population and in age- and gender-specific groups, all residents of a United States county who received transfusion(s) from 1989 through 1992 were studied. STUDY DESIGN AND METHODS: The study was a prevalence survey (cross-sectional study) of a well-defined population at a specified time. RESULTS: There was no significant change in blood and blood component utilization from the beginning of 1989 through 1992. The incidence of red cell transfusion was 42.88 units per 1000 population per year in both men and women and varied from 12.08 units per 1000 population per year in those less than 41 years old to 245.24 units per 1000 population per year in the group aged more than 65. A random resident's probability of receiving transfusion(s) in any year was 0.89 percent (0.83% for men and 0.94% for women) and varied from 0.26 to 5.17 percent among the three age groups. The incidence of platelet and fresh-frozen plasma transfusion was 21.24 units per 1000 population per year and 8.64 units per 1000 population per year, respectively. CONCLUSION: Incidence rates of blood transfusion for "causal" planning of blood collections are presented here for the first time. The probability of receiving a transfusion of RBCs in any year rises by 20-fold from the rate in those less than 40 years old to that in those more than 65 years old, who receive 53.3 percent of the red cell units transfused.     

FS04.2Immunotoxic effects of arylamine dyes

Allergic reactions to arylamine dyes are well‐known causes for allergic contact dermatitis (ACD). These compounds are found in synthetic and natural materials, hair dyes, sun screen, photographic additives as well as temporary tattoos. Cross‐reactions between different para‐compounds have been frequently observed but the underlying mechanisms are not fully elucidated. We investigated the immunogenic capacities of p‐phenylendiamine (PPD), Bandrowski’s base (BB), 2‐methyl‐1,4‐phenylendiammoniumsulfat (PTD), 4‐aminoazobenzene (AAB), disperse orange (DO), disperse yellow (DY), 4–4‐diaminophenylmethan (DDM), bismarckbrown (BBY) and 2‐mercaptobenzothiazole (MBT) by measuring the proliferative responses of T‐cells on polyclonal and monoclonal level (thymidine incorporation). T cell responses were based on CD4+ and CD8+ T cells. Recently, we characterized PPD/BB T cell clones (TCC) as predominantly CD4+/CD45RO+ cells with a alpha/beta T cell receptor (Sieben et al., 2002). We isolated T cell lines (TCL, n = 16) and T cell clones (TCC, n = 20) from totally 11 PPD‐allergic persons and 5 exposed persons. We established TCLs and TCCs to 4 para‐amino compounds. We found some PPD and/or BB specific TCCs with no cross‐reactivity to the other compounds tested. Some TCCs showed a narrow range of cross‐reactions (BB, BBY, MBT), while others reacted to 6 different para‐amino compounds. We observed similiar patterns of crossreaction for the TCLs. The stimulation indices (SI) varied between 2.2 and 14.0. Our preliminary results on cross‐reactions between para‐amino compounds support recent findings in mice (Wulferink et al., 2002) demonstrating a limited discriminatory capacity of T cells carrying an alpha/beta T cell receptor. Further studies on the mechanisms of cross‐reactivities and the cytokine profiles are now under investigation. This study was supported by the Interdiciplinary Center for Clinical Research and Biomaterials (IZKF, Germany) and the Deutsche Forschungsgemeinschaft (Germany).     

Psoriasis: pathophysiology and oral manifestations

Psoriasis is a chronic, remitting and relapsing inflammatory skin disorder with a strong genetic predisposition. Psoriasis affects 1–3% of the world's population in their early lives representing a disabling condition with significant social and economic impact. Despite a great deal of research on the etiology and tissue destruction mechanisms, the disease is not well understood. The purpose of this paper is to provide current information from the literature with a special focus on oral manifestations. The major signs and symptoms presented in the oral environment of a psoriasis patient may include geographic tongue, fissure tongue, gingival and/or mucosal lesions. Inflammatory temporomandibular joint lesions have been reported in less than 5% of psoriasis patients. Multiple treatment strategies, be they topical or systemic, have been applied to these patients for symptom relief but not for cure.     

The measurement of knee-heel length in newborn infants using a simple vernier calipers

Objective: To assess the usefulness of a simple vernier calipers for measuring knee-heel length in neonates. Subjects and methods: Using a simple vernier calipers, knee-heel length was measured five times by 2 observers in 50 babies (29M, 2IF; mean birthweight 1597 g; median gestational age at birth 29 weeks) at a median postnatal age of 11 days. A subgroup of 20 babies had knee-heel length measured similarly at weekly intervals for 3 weeks. Corrected gestational age and weight were simultaneously recorded. One observer was experienced in using the vernier calipers. The precision of the calipers was established using 4 steel gauge blocks of varying length (7.62-10.17 cm). Results: The calipers were very precise when measuring steel gauge blocks. In babies, there was a downward trend across the first 2 measurements for both observers, the measurements stabilizing over the last three. Using the final three measurements per baby (n= 50), the experienced observer had a mean standard deviation of 0.023 cm and mean coefficient of variation 0.23%- when measuring an average knee-heel length of 9.99 cm. The inexperienced observer had a mean standard deviation of 0.057 cm and a mean coefficient of variation of 0.56%, when measuring an average knee-heel length of 10.14 cm. The inter-observer reliability, measured by the intra-class correlation coefficient, was 0.99. The agreement between observers was such that one observer measured knee-heel length consistently less (0.15 cm. SD 0.18 cm) than the other. The reliability for knee-heel length velocity was lower (R= 0.85), but agreement between observers was high with an average difference of 0.016 cm/ week. Knee-heel length was significantly correlated (p < 0.001) with corrected gestational age (r= 0.85) and with weight (r= 0.96). There was a weaker but significant correlation (r= 0.47, p < 0.001) between knee-heel length velocity and rate of weight gain (g/day), indicating that weight gain may not always be accompanied by an increase in linear growth. Conclusion: The measurement of knee-heel length by a simple vernier calipers is an accurate, reproducible and non-invasive method of assessing short-term linear growth in neonates. However, it is recommended that measurements of knee-heel length in a individual baby should be made by a single experienced observer.