Plasma fibronectin in asthmatic patients and its relation to asthma attack

This study investigated the relation between asthma attacks and levels of plasma fibronectin (FN) and serum eosinophilic cationic protein (ECP) in patients with bronchial asthma in order to clarify the role of FN in the airway inflammation of bronchial asthma. Plasma levels of FN were significantly higher (P < 0.025) in patients with bronchial asthma than in healthy controls. They were also significantly higher (P < 0.05) in non-atopic asthmatics than in atopic asthmatics. Furthermore, plasma FN was lower during the attack than the non-attack stage (P < 0.025), and a significant increase of plasma FN was noted (P < 0.05) in asthmatics who had more severe and more frequent attacks. Serum levels of ECP were significantly higher during the attack than the non-attack stage (P < 0.005). An increase of plasma FN in the non-attack stage after attacks showed a significant correlation (P < 0.05) with a decrease of serum ECP. These observations clearly indicate that the decrease in plasma FN associated with attacks is closely related to aggravation of airway inflammation, and that the increase in plasma FN in the non-attack stage reflects chronic airway inflammation. These results suggest that the fluctuation in plasma levels of FN may be one of the factors affecting allergic inflammation and attacks in bronchial asthma.     

应用表达载体介导siRNA抑制乳腺癌细胞MCF-7 血管内皮生长因子-C基因的表达

目的 探讨表达载体介导小干扰RNA(siRNA)对人乳腺癌细胞系MCF-7血管内皮生长因子-C(VEGF-C)表达的抑制作用. 方法 设计合成一对编码后可形成小发夹结构针对VEGF-C基因的siRNA的DNA序列,将其连入pRNAT-U6.1/Neo质粒中,构建VEGF-CsiRNA表达载体.表达载体进行PCR及测序鉴定,并分别转染MCF-7细胞,半定量RT-PCR和免疫组织化学技术检测转染前后MCF-7细胞VEGF-C基因表达的变化. 结果 PCR和DNA测序证实,携带VEGF-CsiRNA表达载体构建成功,VEGF-C基因的mRNA和蛋白表达量与空质粒转染相比均明显下降(P<0.05),在mRNA水平其表达抑制率为61.8%;在蛋白表达水平其表达抑制率为78.3%. 结论 本研究构建的VEGF-CsiRNA表达载体可有效抑制MCF-7细胞VEGF-C的mRNA和蛋白表达,为进一步以VEGF-C为靶点的乳腺癌治疗实验研究奠定了基础.     

人参二醇皂苷对急性血瘀模型大鼠血液流变性及PGF1a、TXB2的影响

目的:观察人参二醇皂苷(Panaxdiols Saponin,PDS)对急性血瘀模型大鼠血液流变性及PGF_1a和TXB₂的影响。方法:Wistar大鼠60只,随机分为6组:对照组;模型组;阳性对照组;PDS5,10,20mg·kg^-1 3个剂量组。采用sc肾上腺素加冰水冷浴法制备大鼠急性血瘀模型,舌下iv给药,观察PDS对急性血瘀模型大鼠血液流变性及PGF_1a和TXB₂的影响。结果:PDS能降低急性血瘀模型大鼠全血黏度,增加心、肺组织中PGF_1a含量,减少TXB₂含量。结论:PDS对急性血瘀模型大鼠血液流变性异常有明显改善作用,能纠正PGF_1a与TXB₂之间的平衡失调。     

The effects of platelet count on clot retraction and tissue plasminogen activator-induced fibrinolysis on thrombelastography

Clot retraction and fibrinolysis may present as a decrease in amplitude on thrombelastography (TEG). The former represents normal or hyperactive platelet function, and the latter represents a fibrinolytic state. It is important to distinguish clot retraction from fibrinolysis because the treatment of each condition is different. To distinguish between these phenomena, we performed TEG with platelet-poor plasma (PPP) and platelet-rich plasma (PRP) with an increasing platelet count (range, 50-1200 x 10(9)/L) with or without abciximab. Maximum amplitude (MA) and the percentage decrease of amplitude at 30 and 60 min after MA were examined for each sample. Blood samples to which tissue plasminogen activator (tPA) was added served as positive controls for fibrinolysis. Morphological changes of clots and D-dimer levels were also examined. With higher platelet counts, the percentage decrease of amplitude after MA increased significantly at 30 and 60 min, but not in the abciximab samples. Morphological changes of clots have shown clot retraction in PRP, but not in PPP or PRP pretreated with abciximab. D-dimer levels increased only in samples to which tPA was added, but not in native PPP or PRP samples. In conclusion, we have shown that the decrease in amplitude at 30 and 60 min can be due to platelet-mediated clot retraction and can be attenuated by sample pretreatment with abciximab, which interrupts platelet-fibrin(ogen) binding.     

Alterations in transmural strains adjacent to ischemic myocardium during acute midcircumflex occlusion

OBJECTIVE: Helically oriented left ventricular fibers assemble into transmural sheets, which are important for wall-thickening mechanics: 15% fiber shortening results in 40% cross-fiber left ventricular wall thickening and a 60% ejection fraction through sheet extension, thickening, and shear. Normal cardiac microstructure and strains are optimized; deviations could result in apoptosis and deleterious matrix remodeling, which degenerates into global cardiomyopathy. We studied alterations in transmural strains adjacent to ischemic myocardium during acute midcircumflex occlusion. METHODS: Nine sheep had radiopaque markers implanted to measure left ventricular systolic fractional area shortening; 3 transmural bead columns were inserted into the midlateral wall for strain analysis. Three-dimensional marker coordinates were obtained with biplane videofluoroscopy before and during 70 seconds of ischemia. Systolic strains were quantified along circumferential, longitudinal, and radial axes (n = 9) and were transformed into fiber-sheet coordinates by using quantitative microstructural measurements (n = 5). RESULTS: A functional border was defined in the midlateral left ventricle; ischemia decreased posterolateral fractional area shortening, and anterolateral fractional area shortening increased. In this demarcation junction, subepicardial end-systolic radial wall thickening decreased (0.16 +/- 0.08 vs 0.11 +/- 0.06) and sheet-normal shear was abolished (0.08 +/- 0.04 vs -0.01 +/- 0.03). Longitudinal shortening decreased in the subepicardium and midwall (-0.05 +/- 0.04 vs +/- -0.01 +/- 0.06), but circumferential-radial shear increased at these depths (0.04 +/- 0.04 vs 0.11 +/- 0.05). Subendocardial fiber stretch occurred during early systole (-0.01 +/- 0.03 vs 0.02 +/- 0.03), and end-systolic fiber-sheet shear increased (0.07 +/- 0.01 vs 0.11 +/- 0.04, all P < .05). CONCLUSIONS: Increased circumferential-radial shear and altered fiber-sheet strains reflect mechanical interactions between ischemic and nonischemic myocardium, which might be important in triggering remodeling processes that evolve into global ischemic cardiomyopathy.     

A trial of fresh autologous whole blood to treat dilutional coagulopathy following cardiopulmonary bypass in infants

BACKGROUND: Transfusion of fresh whole blood is superior to blood component therapy in correcting coagulopathies in children following cardiopulmonary bypass (CPB); however, a supply of fresh homologous whole blood is difficult to maintain. We hypothesized that transfusion of fresh autologous whole blood obtained prior to heparinization for CPB and infused following CPB would be associated with improved coagulation function when compared with standard therapy. METHODS: A total of 32 infants 5-12 kg undergoing noncomplex open cardiac surgery were randomly assigned to either the treatment or control group. In the treatment group, 15 ml x kg(-1) of autologous whole blood was collected into a CPDA bag prior to heparinization while 15 ml x kg(-1) of 5% albumin was infused intravenously. After reversal of heparin, coagulation tests were drawn in both groups, and the autologous whole blood was infused over 20 min in the treatment group. RESULTS: The treatment group had greater (P < 0.05) improvement in platelet count, prothrombin time, and fibrinogen than the control group. CONCLUSIONS: We conclude that collection of fresh autologous whole blood prior to heparinization and reinfusion following CPB is associated with greater improvement of coagulation status after CPB in infants.     

Review article: lactose--a potential prebiotic

Lactose maldigestion, which affects a large majority of the world's population, has been mostly linked with uncomfortable symptoms. In addition, dairy consumption is variably blamed or recommended for a number of ill effects. There is, however, emerging evidence that certain lactic acid-producing bacteria, which selectively consume prebiotics, may be beneficial against some lower intestinal diseases. Lactose maldigestion and lactose should perhaps be re-evaluated as a potential provider of such a prebiotic. This historical and observational review discusses lactose and argues the opinion that it has prebiotic potential. Moreover, in maldigesters, natural ingestion or lack thereof may be relevant in the pathogenesis of diseases such as colorectal cancer and inflammatory bowel diseases.