Australian children and the threat of nuclear war

Seven hundred and one 10- to 13-year-old schoolchildren from 20 schools in the Hunter region of New South Wales were asked questions about the future. The questionnaire, which was in two main sections, commenced with general, open-ended questions about the children's expectations, hopes and wishes. It then moved to more specific questions which were designed to assess the children's current level of knowledge about nuclear war. In the unprompted section, 56% of the children mentioned war as one of their concerns, while 33% wrote specifically of nuclear war. In answer to specific questions, the majority (97%) of children reported being aware of the issues of nuclear armaments and nuclear war. Sixty-eight per cent of children considered that nuclear war will or might occur; 31% felt that this would be within their own lifetimes. Most of the children reported the mass media to be their source of information on these issues; very few had heard about them from family or friends. The results challenge a commonly expressed belief that children of this age are not aware of the nuclear arms situation. Awareness of this issue and its implications, which is coupled with a lack of opportunities for discussion, may be detrimental to the well-being of children.     

Platelet transfusion from donors mismatched for crossreactive HLA antigens

Increments in platelet counts following the transfusion of platelets mismatched for crossreactive antigens were evaluated in 67 patients with broad alloimmunization to HLA antigens. The corrected increments following 100 HLA, A-matched and B1U- or B2U-matched transfusions were compared with the increments following 307 B1X- or B2X-matched transfusions. HLA-A3 platelets were tolerated poorly by A1 and A11 recipients, as were A1 and A11 by A3 recipients, B17 and BW21 by recipients in the B7 crossreactive group, B5 by B15 and B17 recipients, and B27 by recipients in the B5 crossreactive group. B12 and BW21, and B8 and B14 platelets were not tolerated bidirectionally. Antigens associated with good increments included A28 in A2 recipients, B18 and BW16 (C match) in recipients in the B5 crossreactive group, B5 in B18 recipients, BW22 and B7 in recipients in the B7 crossreactive group. A1 and A11 were transfused successfully bidirectionally. These observations suggest that some private antigens within crossreactive groups are more immunogenic than others and support the observation of others than B17 and BW21 are not in the B5 crossreactive group.     

Residual WBC subsets in filtered prestorage RBCs

BACKGROUND: New-generation RBC filters reduce WBC concentrations by 4 to 5 logs and may prevent or decrease transfusion complications such as HLA alloimmunization, nonhemolytic febrile reaction, and transfusion-transmitted infections. The residual level of WBC subsets may influence efficacy of WBC reduction for preventing various complications. This study analyzed subsets of residual WBCs in WBC-reduced RBC components prepared for a large, multicenter prospective study. STUDY DESIGN AND METHODS: The Viral Activation Transfusion Study (VATS) assessed the impact of WBC reduction in HIV-1-infected patients undergoing RBC transfusion. WBC-reduced RBC from 11 clinical sites with variable filtration practices were sorted into "low,"middle," and "high" groups based on residual WBC concentration. Subsets were isolated from units by immunocapture (anti-CD4-, anti-CD8-, anti-CD15-, and anti-CD19-coated magnetic beads) and quantified by PCR amplification. RESULTS: After validation studies confirming test methodology, 105 VATS WBC-reduced RBC samples were analyzed. Concentrations of subsets in low and middle residual WBC groups were very low in contrast to relatively high concentrations in the high group. Although highly significant differences were identified between the middle and high groups for total WBCs and all subsets, no single subset predominated. CONCLUSION: These results suggest that overall efficacy of WBC filtration correlates with removal of WBC subsets.     

Hypergammaglobulinemia can be associated with a positive direct antiglobulin test, a nonreactive eluate, and no evidence of hemolysis

To determine the cause of a positive direct antiglobulin test (DAT), blood banks routinely perform serologic tests on eluates prepared from DAT-positive red cells. Negative eluates traditionally have been suspected to be associated with drug reactions. This report confirms that the most frequent cause of a positive DAT and a nonreactive eluate is hypergammaglobulinemia. The results of 74 patient samples with positive DATs were analyzed retrospectively. Eluates prepared from the red cells of 54 patients (72.9%) reacted; eluates from 20 patients (27.1%) did not react. This latter group had identical serologic and clinical findings, suggesting that they made up a homogeneous group. In particular, the patients had a positive DAT, a negative indirect antiglobulin test, and a negative eluate; an increased serum concentration of IgG; and no evidence of hemolysis. In a subsequent study, DATs were performed prospectively on red cells from 44 consecutive patients with elevated serum IgG levels. The serum IgG concentration was highest in the three patients whose red cells had a positive DAT. The DAT also became positive in two patients treated with high-dose intravenous gammaglobulin (IV IgG). These studies indicate that a negative eluate from red cells with a positive DAT, a common serologic finding, is often caused by hypergammaglobulinemia. The authors postulate that IgG binds nonspecifically to the red cells because of the hypergammaglobulinemia.     

聚乙二醇在猪组织工程瓣膜制备中的应用

目的:观察聚乙二醇法在组织工程瓣膜准备中的应用价值,比较聚乙二醇去细胞前后组织工程瓣膜的物理特性。方法:实验于2005-10/2006-03在华中科技大学同济医学院基础医学院生物化学系实验室完成。①实验分组:取猪10只,由于猪主动脉瓣为三叶瓣结构,共取得瓣叶组织30个,麻醉后宰杀取其心脏动脉瓣膜,分为去细胞组和对照组,每组各15个。②实验方法:去细胞组用聚乙二醇和DNase I处理;瓣叶组织放入1kg/L聚乙二醇,室温下浸泡30～45min,振荡器加以振荡;含抗生素磷酸盐缓冲液浸泡24h,反复3次洗脱;以5×104U/L DNase I液浸泡处理1h;对照组仅以含抗生素磷酸盐缓冲液浸泡24h,反复3次洗脱。③实验评估:苏木精-伊红染色、扫描电镜观察去细胞情况,吸光度(A)值,计算去细胞率(%)=(对照组A值-去细胞组A值)/对照组A值×100%。猪去细胞瓣膜条置于力学测试仪测定最大负荷、最大应力、最大应变和弹性模量。结果:纳入猪10只,均进入结果分析。①去细胞组织形态学观察:去细胞组猪瓣膜组织中看不到细胞成分,且细胞外基质结构保存完整,胶原纤维排列整齐,无明显断裂,仍呈波浪状平行排列,结构紧凑,弹性纤维结构清晰,组织无明显水肿。②DNA含量分析:聚乙二醇处理后去细胞百分率为95.32%。③生物力学检测:与对照组比较,去细胞组瓣膜组织最大负荷[(12.586±1.693),(10.242±1.435)N,P>0.05]、最大应力[(2.346±0.342),(1.877±0.572)N/mm,P>0.05]、弹性模量(15.152±1.579,14.549±0.678,P>0.05)、最大应变[(31.685±7.533),(28.118±6.045)mm/N,>0.05]等均无显著差异。P结论:聚乙二醇法去除细胞完全,细胞外基质保存完整,对组织机械性能无明显影响,适于构建组织工程瓣膜。     

Localization and determination of infarct size by Gd-Mesoporphyrin enhanced MRI in dogs

Background: Accurate localization and sizing of a myocardial infarction are necessary for clinical decision making and even more in research. Gd-Mesoporphyrin enhanced magnetic resonance imaging (MRI) was recently shown to specifically delineate necrosis in liver tumors, renal and muscle necrosis and myocardial infarction in rats. In this study, we investigated this technique's potential to accurately delineate myocardial infarction in a larger animal species, the dog. Methods: Myocardial infarction was induced in 8 dogs by ligation of the left anterior descending coronary artery, 4 of which were reperfused after 3 hr. Gd-Mesoporphyrin (0.05 mmol/kg) was injected intravenously 210 min after the onset of ischemia (n = 6) or after 24 hr in 2 dogs with non-reperfused infarctions. MRI was performed 10 hr. after administration of Gd-Mesoporphyrin. In vivo MRI consisted of EKG-triggered, respiratory gated T1-weighted spin echo and segmented turboFLASH long and short axis measurements. Post-mortem, a spin echo short axis measurement was repeated. Infarct size was determined planimetrically by TTC staining of left ventricular slices. Results: In all instances, there was a very close qualitative agreement between the MRI and TTC defined myocardial infarction. Quantitatively, the linear regression from post-mortem MRI to TTC determined infarct size yielded a result very close to the line of identity (regression coefficient: 0.980 ± 0.026, p<0.000001, adjusted R² = 0.964). Conclusion: We conclude that Gd-Mesoporphyrin enhanced MRI is a promising tool for the accurate delineation of myocardial infarction.