Proton nuclear magnetic resonance imaging of regionally ischemic canine hearts: effect of paramagnetic proton signal enhancement

In a study to evaluate the potential of proton nuclear magnetic resonance (NMR) imaging with and without manganese contrast with and without manganese contrast enhancement for detecting acute myocardial infarction, 12 dogs underwent 90-minute occlusion of the left circumflex coronary artery. Transverse-section NMR images of the excised, nonbeating heart were obtained at 1-cm intervals using the steady-state-free-precession (SSFP) technique. All NMR images revealed detailed structure of the heart. The three hearts without manganese showed no difference in intensity between the normal and the ischemic posterior regions, whereas those with manganese demonstrated a clearly demarcated zone of reduced signal intensity consistent with the ischemic zone. It is concluded that high-resolution tomograms of the excised canine myocardium can be obtained using proton NMR imaging. With the SSFP imaging technique, proton signal enhancement with manganese infusion is necessary to differentiate between ischemic and nonischemic myocardium after 90 minutes of coronary occlusion.     

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 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.