Simultaneous collection of platelets and cryoprecipitate by plasma- exchange donation

To increase cost efficiency, the simultaneous collection of platelets during plasma-exchange donation of cryoprecipitate was investigated. Sixteen desmopressin (DDAVP)-stimulated donors underwent 90 simultaneous donations. Permanent donor plasma loss for each donation averaged 150 ml in cryoprecipitate and 151 ml in platelet concentrates. Mean factor VIII (FVIII) yield was 4699 +/- 2754 IU per donation. The mean yield in the platelet products was 4.63 X 10(11) platelets; aggregation properties and posttransfusion increments were satisfactory. White cell contamination averaged 4.05 X 10(9) but could be lowered by a secondary centrifugation. The direct cost for a single-donor platelet transfusion produced in this way is estimated at $102.19 and that for FVIII at $0.055 per IU. Simultaneous donation is technically feasible and safe for donors, and it provides functional products that are more cost-effective than apheresis platelets or cryoprecipitate donated separately.     

The HLA-DQ2 gene dose effect in celiac disease is directly related to the magnitude and breadth of gluten-specific T cell responses

In patients with celiac disease, inflammatory T cell responses to HLA-DQ2-bound gluten peptides are thought to cause disease. Two types of HLA-DQ2 molecules exist, termed HLA-DQ2.5 and HLA-DQ2.2. Whereas HLA-DQ2.5 predisposes to celiac disease, HLA-DQ2.2 does not. We now provide evidence that the disease-associated HLA-DQ2.5 molecule presents a large repertoire of gluten peptides, whereas the non-disease-associated HLA-DQ2.2 molecule can present only a subset of these. Moreover, gluten presentation by HLA-DQ2 homozygous antigen-presenting cells was superior to presentation by HLA-DQ2/non-DQ2 heterozygous antigen-presenting cells in terms of T cell proliferation and cytokine secretion. Gluten presentation by HLA-DQ2.5/2.2 heterozygous antigen-presenting cells induced intermediate T cell stimulation. These results correlated with peptide binding to the antigen-presenting cells. Finally, we demonstrate that HLA-DQ trans dimers formed in HLA-DQ2.5/2.2 heterozygous individuals have properties identical with HLA-DQ2.5 dimers. Our findings explain the strongly increased risk of disease development for HLA-DQ2.5 homozygous and HLA-DQ2.2/2.5 heterozygous individuals, and they are indicative of a quantitative model for disease development, where HLA-DQ expression and the available number of T cell-stimulatory gluten peptides are critical limiting factors. This model may have important implications for disease prevention.     

The preterm parturition syndrome

The implicit paradigm that has governed the study and clinical management of preterm labour is that term and preterm parturition are the same processes, except for the gestational age at which they occur. Indeed, both share a common pathway composed of uterine contractility, cervical dilatation and activation of the membranes/decidua. This review explores the concept that while term labour results from physiological activation of the components of the common pathway, preterm labour arises from pathological signalling and activation of one or more components of the common pathway of parturition. The term 'great obstetrical syndromes' has been coined to reframe the concept of obstetrical disease. Such syndromes are characterised by: (1) multiple aetiology; (2) long preclinical stage; (3) frequent fetal involvement; (4) clinical manifestations that are often adaptive in nature; and (5) gene–environment interactions that may predispose to the syndromes. This article reviews the evidence indicating that the pathological processes implicated in the preterm parturition syndrome include: (1) intrauterine infection/inflammation; (2) uterine ischaemia; (3) uterine overdistension; (4) abnormal allograft reaction; (5) allergy; (6) cervical insufficiency; and (7) hormonal disorders (progesterone related and corticotrophin-releasing factor related). The implications of this conceptual framework for the prevention, diagnosis, and treatment of preterm labour are discussed.     

微囊化人工细胞技术在神经系统疾病治疗中的应用

目的:对微囊化人工细胞技术在神经系统疾病治疗的应用研究进展作一综述。资料来源:检索PubMed数据库中1980-01/2007-04有关人工细胞微囊技术进展的文章,检索词“microcapsule,artificial cell,transplantation”,并限定文献语言种类为English。同时检索中国知网中国期刊全文数据库1994-01/2007-05的相关文章,检索词为“微囊化,人工细胞,移植”。资料选择:纳入标准:①人工细胞微囊治疗帕金森病、脊髓损伤、神经再生的研究。②人工细胞微囊生物特性的研究。③动物实验。排除标准:①较陈旧的文献。②重复研究。资料提炼:共收集到符合上述要求的文献65篇,49篇符合纳入标准。其中研究内容相似的,以近3年内发表在较权威杂志者优先。排除的20篇为较陈旧的文献及重复研究;对符合标准的29篇文献进行分析。资料综合:微囊化人工细胞技术作为一种有效的免疫隔离技术,与现代基因工程技术相结合,能够成功的包裹部分神经功能细胞或基因工程细胞,并可明显提高移植细胞在体内的存活时间,同时发挥一定的生理功能,在帕金森病、脊髓损伤、周围神经再生、镇痛等方面的治疗方面取得了良好的效果。结论:微囊化技术可以有效的避免免疫排斥反应对移植细胞的损伤,日益成熟的人工细胞微囊技术在神经系统疾病治疗方面的广阔的应用前景。     

Overlap of migraine and tension-type headache in the International Headache Society classification

Using questionnaire data from two recent surveys, headache sufferers were classified as having either migraine, episodic, or chronic tension-type headache using the International Headache Society criteria. Of 410 subjects with a headache history of 2 years or more, 147 or 35.9% were assigned Code 1.7 (migrainous disorder not fulfilling the above criteria) or Code 2.3 (headache of the tension-type not fulfilling above criteria). In 79 of these 147 subjects (53.7%), either of the above codes would have been equally valid. Separate scores for "migraine" and "tension" symptoms may provide a way to handle this overlap and aid in choosing optimal therapy.     

温固化水凝胶复合细胞外基质与膀胱平滑肌细胞的相容性

目的:选用膀胱平滑肌细胞为实验细胞,评估细胞外基质/温度敏感性水凝胶复合支架材料的生物相容性。方法:实验于2005-02/05在武汉大学人民医院泌尿外科研究室完成。①实验分组:实验分为4组。细胞外基质/温度敏感性水凝胶复合支架组:细胞外基质/温度敏感性水凝胶复合支架种植平滑肌细胞;单纯细胞外基质组:单纯细胞外基质种植平滑肌细胞;阴性对照组:单纯培养平滑肌细胞;空白对照组:无细胞培养液。②实验操作:种植细胞前先用培养液将支架材料预湿,取第3代兔膀胱平滑肌细胞悬液(1×108L-1)50μL缓慢接种于材料上。③实验评估:培养2d后倒置相差显微镜下观察细胞黏附、生长情况以及扫描电镜下观察细胞在材料上的空间生长情况;培养5,10d取细胞外基质/温度敏感性水凝胶复合支架组、单纯细胞外基质组材料,进行细胞计数,观察细胞黏附数量;培养1,3,5,7d时MTT法检测细胞的活力。结果:①相差显微镜下可见细胞外基质/温度敏感性水凝胶复合材料为红染的网状结构,纤维较粗,网孔直径较小,未见到细胞碎片;种植平滑肌细胞后6h,可见细胞紧密黏附于材料表面;种植平滑肌细胞后12h,可见细胞已伸展,有多个突起;培养3d时,贴附于材料的细胞数量增加,细胞增殖明显。②扫描电镜下可见发育良好的细胞附于材料上,伪足沿纤维伸展,附着牢固,细胞间连接紧密,可见到细胞外基质分泌。③膀胱平滑肌细胞在单纯细胞外基质上黏附性良好,黏附率为87.6%,复合温度敏感性水凝胶后的细胞外基质表面黏附能力较之增强,黏附率为96.7%。④细胞活力:细胞外基质/温度敏感性水凝胶复合支架组、阴性对照组细胞活力(A)高于单纯细胞外基质组,差异有显著性意义(P<0.05,0.01),培养1,3,5d细胞外基质/温度敏感性水凝胶复合支架组细胞活力(A)低于阴性对照组,培养7d高于阴性对照组,差异有显著性意义(P<0.05,0.01)。结论:细胞外基质/温度敏感性水凝胶复合材料具有便于细胞黏附和生长的微孔结构,生物相容性好,并且保留的某些成分具有良好的促组织再生作用,是一种理想的组织工程材料。     

Crossover use of donated blood for autologous transfusion: report of the Council on Scientific Affairs, American Medical Association

BACKGROUND: Controversy exists concerning whether the costs and potential risks outweigh the potential benefits of "crossover" use in the general blood supply of unutilized blood that was donated for autologous transfusion. STUDY DESIGN AND METHODS: Published articles and reports were identified through systematic search of MEDLINE and review of references cited in previously identified articles, textbooks, and reports. Consultation was made with experts in blood donation and transfusion. Additional peer review was received from the American Medical Association (AMA) Council on Scientific Affairs RESULTS: Concern over infectious disease transmission has led to increased interest in and support for autologous transfusion for individuals having planned surgeries. Different requirements exist for collection, labeling, and screening of blood to be used for autologous versus allogeneic transfusions; therefore, procedures for diverting autologous blood donations to the general blood supply involve considerable expense. Several cost-effectiveness studies of autologous blood donation and transfusion conclude that currently this "crossover" appears to be an expensive procedure yielding little increased benefit from a societal perspective. CONCLUSIONS: The recommendations in this report were adopted as AMA Policy at the AMA Annual Meeting in June 1997. The AMA does not encourage blood collection programs to "cross over" units donated for autologous use to the allogeneic blood supply. Practice guidelines are needed, and should be utilized to ensure parsimony in the use of autologous blood donations and transfusions.