Scintigraphic diagnosis of tricuspid regurgitation

The authors describe a simple technique for diagnosis of tricuspid regurgitation. Red blood cells were labeled in vivo with 99mTc and 22 patients were studied with ECG-gated blood-pool imaging of the liver. A single region of interest was manually drawn around the liver and a time-activity curve obtained. The per cent change in liver counts during the cardiac cycle was found to be significantly higher in the 12 patients with tricuspid regurgitation (Group I) (mean, 4.04 +/- 1.6%; range, 1.3-21.4%) compared with the 10 controls (Group II) (mean, 0.35 +/- 0.16%; range, 0.013-1.3%) (p less than 0.05). Using a 1% change in liver counts as the criterion of a positive study, all 12 cases in Group I were diagnosed correctly, but there was one false positive in Group II; thus the sensitivity was 100% and the specificity 90%.     

Pericardial ectopic thymoma

Primary intrapericardial thymoma is an unusual localization. We report a case of a patient with an isolated and primary pericardial thymoma. This 72-year-old woman presented with dyspnea, dysphony and myalgia. The radiological evaluation revealed an intrapericardial mass. Surgical exploration showed a hemorrhagic and infiltrative tumor in the pericardial sac, while the mediastinum was free of tumor. Surgical biopsies and, later, an ablation of pericardial mass were done. The tumor was a thymoma, composed of large epithelial cells and immature T lymphocytes and was classified B2 according to the World Health Organization classification (1999). Clinically, a myasthenia gravis was revealed. We discuss the few cases reported in the literature.     

Cyclo-oxygenase and lipoxygenase pathways in mast cell dependent-neurogenic inflammation induced by electrical stimulation of the rat saphenous nerve

1. We investigated the role of arachidonic acid metabolism and assessed the participation of mast cells and leukocytes in neurogenic inflammation in rat paw skin. We compared the effect of lipoxygenase (LOX) and cyclo-oxygenase (COX) inhibitors on oedema induced by saphenous nerve stimulation, substance P (SP), and compound 48/80. 2. Intravenous (i.v.) pre-treatment with a dual COX/LOX inhibitor (RWJ 63556), a dual LOX inhibitor/cysteinyl-leukotriene (CysLt) receptor antagonist (Rev 5901), a LOX inhibitor (AA 861), a five-lipoxygenase activating factor (FLAP) inhibitor (MK 886), or a glutathione S-transferase inhibitor (ethacrynic acid) significantly inhibited (40 to 60%) the development of neurogenic oedema, but did not affect cutaneous blood flow. Intradermal (i.d.) injection of LOX inhibitors reduced SP-induced oedema (up to 50% for RWJ 63556 and MK 886), whereas ethacrynic acid had a potentiating effect. 3. Indomethacin and rofecoxib, a highly selective COX-2 inhibitor, did not affect neurogenic and SP-induced oedema. Surprisingly, the structurally related COX-2 inhibitors, NS 398 and nimesulide, significantly reduced both neurogenic and SP-induced oedema (70% and 42% for neurogenic oedema, respectively; 49% and 46% for SP-induced oedema, respectively). 4. COX-2 mRNA was undetectable in saphenous nerves and paw skin biopsy samples, before and after saphenous nerve stimulation. 5. A mast cell stabilizer, cromolyn, and a H(1) receptor antagonist, mepyramine, significantly inhibited neurogenic (51% and 43%, respectively) and SP-induced oedema (67% and 63%, respectively). 6. The co-injection of LOX inhibitors and compound 48/80 did not alter the effects of compound 48/80. Conversely, ethacrynic acid had a significant potentiating effect. The pharmacological profile of the effect of COX inhibitors on compound 48/80-induced oedema was similar to that of neurogenic and SP-induced oedema. 7. The polysaccharide, fucoidan (an inhibitor of leukocyte rolling) did not affect neurogenic or SP-induced oedema. 8. Thus, (i) SP-induced leukotriene synthesis is involved in the development of neurogenic oedema in rat paw skin; (ii) this leukotriene-mediated plasma extravasation might be independent of mast cell activation and/or of the adhesion of leukocytes to the endothelium; (iii) COX did not appear to play a significant role in this process.     

银杏叶制剂对心绞痛患者的抗氧化和抗脂质过氧化作用

目的：探讨银杏叶制剂对心绞痛患者的抗氧化和抗脂质过氧化作用。方法：检测了７８例心绞痛患者经银杏叶制剂“天宝宁”治疗前后的血浆维生素Ｃ（Ｐ－ＶＣ）、维生素Ｅ（Ｐ－ＶＥ）、β－胡萝卜素（Ｐ－β－ＣＡＲ）、过氧化脂质（Ｐ－ＬＰＯ）以及红细胞超氧化物歧化酶（Ｅ－ＳＯＤ）、过氧化氢酶（Ｅ－ＣＡＴ）、谷胱甘肽过氧化物酶（Ｅ－ＧＳＨ－ＰＸ）、过氧化脂质（Ｅ－ＬＰＯ）值。结果：与治疗前比较,治疗后的Ｐ－ＶＣ、Ｐ－     

控制和影响神经干细胞增殖分化为神经元细胞的途径及因素

目的:探讨控制和影响神经干细胞向神经元细胞转化途径的因素。资料来源:应用计算机检索Medline和cnki数据库1990-01/2006-06期间的有关神经干细胞和增殖与分化关系的文献,检索词“NSC,proliferation,differentiation”,并限定文章语言种类为English。同时计算机检索中国生物医学文献数据库1990-01/2006-06期间的相关文献,限定文章语言种类为中文,检索词“神经干细胞、增殖、分化”。资料选择:选取关于影响神经干细胞增殖与分化特别是机制方面的相关文献,删除未进行对照的试验研究的文章,然后查余下的文献全文,进一步判断是否采用对照。纳入标准:平行对照组,即未采用影响神经干细胞增殖与分化的因素或正常对照;实验组为采用干扰神经干细胞增殖与分化的因素。排除明显不随机的试验。质量评价主要考察资料的真实性,调查设计是否严密,实施过程是否严格,统计学处理是否合理。资料提炼:共检索43篇关于神经干细胞增殖与分化分别与基因调控、生长因子、细胞因子及微环境信号等因素密切相关文章,31编符合纳入标准。排除的12篇试验中,8篇是因重复的同一研究,4篇是Meta分析研究。资料综合:神经干细胞是一种具有强大的自我更新能力和多向分化潜能的细胞,它具有分化为中枢神经系统内神经元、星形胶质细胞和少突胶质细胞的能力;其增殖与分化与基因调控、生长因子、细胞因子及微环境信号等因素密切相关,基本螺旋-环-螺旋基因、凋亡相关基因Bc1-XL、sox2等参与了神经干细胞的定向分化机制,notch信号通路、过氧化物酶体增殖分化激活受体Y信号通路也影响神经干细胞的分化方向。结论:神经干细胞的增殖与分化机制尚不十分清楚,其分化及调控机制是多因素调节和多因素相互作用的结果。