羟乙基淀粉溶液术前扩容对围术期冠心病患者血小板活化的影响

 【目的】 观察两种羟乙基淀粉（HES）溶液术前扩容对冠心病患者围术期血小板膜糖蛋白Ⅱb/Ⅲa（GPⅡb /Ⅲa）、GMP-140表达的影响。【方法】 全麻下接受胆囊切除术的冠心病患者45例，心功能Ⅰ-Ⅱ级，随机分为3组（n＝15）：术前以10 ml·kg-1剂量于30 min内输注HES200/0．5（组Ⅰ）、HES130/0．4（组Ⅱ）和乳酸钠林格氏（RL）溶液（组Ⅲ）。抽取静脉血，采用流式细胞仪检测麻醉前（T0）、扩容结束后即刻（T1）、扩容结束后1h（T2）、手术结束后2 h（T3）时 GPⅡb/Ⅲa与GMP-140的表达。【结果】 组ⅠT1 、T2 和 T3时GPⅡb/Ⅲa表达较T0降低；与组Ⅱ、组Ⅲ比较，组Ⅰ扩容后的GPⅡb/Ⅲa表达降低（P<0．05）；组ⅡT1时GPⅡb/Ⅲa表达较T0降低（P<0．05）；与组Ⅲ比较，组ⅡT1 和 T3时GPⅡb/Ⅲa表达降低（P<0．05）；组ⅢT3时GPⅡb/Ⅲa表达较T0增加；组ⅠT1、T2 和 T3时GMP-140表达较T0降低（P<0．05）；与组Ⅱ、组Ⅲ比较，组Ⅰ扩容后的GMP-140表达降低（P<0．05）；与组Ⅲ比较，组ⅡT2和 T3时GMP-140表达降低（P<0．05）；组ⅢT2和T3时GMP-140表达较T0增加（P<0．05）。【结论】 术前采用HES溶液扩容能抑制血小板GPⅡb/Ⅲa复合物与GMP-140表达，其中HES200/0．5作用较HES130/0．4明显。此作用对避免不稳定斑块处血小板的进一步积聚，防止围术期冠心病患者病情恶化可能有一定的作用。     

钛酸四丁酯增韧改性聚乳酸/淀粉共混材料

制备了钛酸四丁酯[Ti(OBu)4]增韧改性的聚乳酸(PLA)/淀粉共混材料,测试了材料的加工流变性能、力学性能、共混形态、结晶性能及疏水性能和降解性能。结果表明:当mTi(OBu)4∶mPLA=0.20时,共混材料的冲击强度提高了40.9%,而弯曲强度下降了59.2%;FT-IR和SEM显示钛酸四丁酯的化学架桥作用增加了共混材料中聚乳酸与淀粉的相容,其吸水率随钛酸四丁酯含量的增加而减少,掩埋150 d后质量下降5%~8%。     

Dietary resistant starch and chronic inflammatory bowel diseases

These studies were performed to test the benefit of resistant starch on ulcerative colitis via prebiotic and butyrate effects. Butyrate, propionate, and acetate are produced in the colon of mammals as a result of microbial fermentation of resistant starch and other dietary fibers. Butyrate plays an important role in the colonic mucosal growth and epithelial proliferation. A reduction in the colonic butyrate level induces chronic mucosal atrophy. Short-chain fatty acid enemas increase mucosal generation, crypt length, and DNA content of the colonocytes. They also ameliorate symptoms of ulcerative colitis in human patients and rats injected with trinitrobenzene sulfonic acid (TNBS). Butyrate, and also to a lesser degree propionate, are substrates for the aerobic energy metabolism, and trophic factors of the colonocytes. Adverse butyrate effects occur in normal and neoplastic colonic cells. In normal cells, butyrate induces proliferation at the crypt base, while inhibiting proliferation at the crypt surface. In neoplastic cells, butyrate inhibits DNA synthesis and arrests cell growth in the G1 phase of the cell cycle. The improvement of the TNBS-induced colonic inflammation occurred earlier in the resistant starch (RS)-fed rats than in the RS-free group. This benefit coincided with activation of colonic epithelial cell proliferation and the subsequent restoration of apoptosis. The noncollagenous basement membrane protein laminin was regenerated initially in the RS-fed group, demonstrating what could be a considered lower damage to the intestinal barrier function. The calculation of intestinal short-chain fatty acid absorption confirmed this conclusion. The uptake of short-chain fatty acids in the colon is strongly inhibited in the RS-free group, but only slightly reduced in the animals fed with RS. Additionally, RS enhanced the growth of intestinal bacteria assumed to promote health. Further studies involving patients suffering from ulcerative colitis are necessary to determine the importance of RS in the therapy of a number of intestinal diseases and the maintenance of health. Accepted: 11 August 1999     

Calcium Responsive Bioerodible Drug Delivery System

Pharmaceutical Research -     

肝移植术中运用贺斯和白蛋白对肺功能的影响

目的探讨中分子羟乙基淀粉(贺斯)和白蛋白在肝移植术中应用对患者术后肺功能的影响。方法选择30例拟肝移植术患者,随机分为贺斯组和白蛋白组,分别与术后6、12、18 h取动脉血测定血气、混合静脉血气、计算氧合指数和肺泡-动脉氧分压差[P(A-a)DO2],记录术后呼吸机应用时间。结果白蛋白组术后12、24 h血管外肺水显著高于贺斯组(P<0.05);血管外肺水两组术后不同时间点P(A-a)O2的变化无明显差异;两组术后不同时间点氧合指数的变化无明显差异。白蛋白组患者术后呼吸机应用时间显著长于贺斯组(P<0.05)。结论贺斯能改善肝移植术后肺功能,与其治疗毛细血管渗漏综合征有关。     

Dietary fibre and health: an overview

Summary Many studies have found that people on diets high in fibre have reduced risks of certain diseases such as cancers, coronary heart disease, obesity and possibly diabetes. Fibre is a collective term for a group of compounds, which differ in their chemical structure and physical properties and elicit a variety of physiological effects. Some health benefits linked to fibre consumption are well established (e.g. promoting a regular bowel habit) and others are becoming more firmly established. The effects of the various non‐digestible components are not always fully interchangeable, although there is considerable overlap, but they share an ability to pass undigested into the large bowel. This makes it important that fibre intake comes from a range of sources to ensure maximum health benefits. There are disagreements as to which plant‐derived compounds constitute ‘fibre’ and which analytical methodologies should be used to determine the fibre content of foods. This lack of a universal definition for these carbohydrates that resist digestion in the small intestine has led to complications in establishing and communicating consistent recommendations for the type and amounts of fibre components in the diet, as well as issues related to food labelling and health claims. Furthermore, current analytical methods may typically underestimate the fibre content of foods, using the definition advised by the European Food Safety Authority. Chemical nomenclature is necessary for a coherent and enforceable approach to the measurement of fibre (and related to this, product labelling), but reconciling chemical definitions for fibre with definitions that reflect physiological effects remains a major challenge. Progress in the application of the emerging evidence regarding dietary fibre and health is constrained by a need to resolve the definition and methodology issues. Most consumers are likely to be unaware of the more recent developments and the overlapping properties of different types of carbohydrate that resist digestion in the small intestine, and the particular sources of these carbohydrates. Long overdue is the translation of the growing knowledge about the physiological properties of carbohydrates, particularly non‐digestible carbohydrates, into clear and unambiguous public health messages. Many terms in common use stem from chemistry rather than physiology, and this makes derivation of health messages more difficult. Meanwhile in the UK, where the main sources of fibre are cereals and cereal products, followed by vegetables and potatoes, adults are not meeting the recommended 18 g of fibre per day (defined in the UK as non‐starch polysaccharide measured by the Englyst method). The recommended amount for the UK, established in 1991, is lower than elsewhere in the world and corresponds to about 24 g according to the method used by the Association of Official Analytical Chemists (the AOAC method). Reference values in other parts of the world are typically between 25 and 35 g (AOAC fibre). A diet rich in whole grains, pulses, fruit and vegetables will assist in meeting current fibre recommendations, but a growing number of other foods now contain carbohydrate‐derived ingredients that resist digestion.     

乳腺癌患者术中急性扩容性血液稀释的价值研究

目的探讨乳腺癌手术患者行急性扩容性血液稀释的应用价值和安全性。方法将40例乳腺癌患者随机分为H组和L组各20例,2组患者术前滴注硝酸甘油扩血管,然后H组和L组30 min内分别从中心静脉快速输入羟乙基淀粉1 000 mL和乳酸林格氏液1 000 mL,观察患者术后总尿量、失血量、补液量、硝酸甘油的用量和手术时间,比较2组患者血红蛋白(Hb)、红细胞压积(Hct)、血小板(Pt)和凝血全套及血流动力学指标等变化。结果2组患者手术总用时、总失血量、总尿量、硝酸甘油的用量差异不大(P>0.05),H组患者所需总补液量少于L组(P<0.05);H组患者扩容后10 min内血常规、凝血酶谱、血流动力学指标均无明显改变;术后H组患者PT、TT值延长(P<0.05),但未超出正常指标,其他指标差异不大。结论急性扩容性血液稀释作为替代输血的一种临时应急手段,简单可行、安全,是节约用血、血液保护的一项切实有效可行的方法。     

急性等容性血液稀释对心肌缺血再灌注损伤的保护作用

目的：研究用6％羟乙基淀粉（HES）行等容血液稀释（ANH）对心肌缺血再灌注损伤的保护作用及其机制。方法：14只大白兔随机分为对照组（A组）和HES组（B组），B组动物左冠状动脉阻断前放血，同时用HES进行血液稀释；A组动物除左冠状动脉阻断同B组外，不作其它处理。两组在再灌注前后，基础状态（T0），心肌缺血前（T1），心肌再灌注后1分钟（R1），再灌注后30分钟（R30）和再灌注后120分钟（R120）分别进行血液动力学和生化指标检测。结果：再灌注120分钟后，B组心率收缩压乘积（RPP）显著高于A组（P＜0．05），血清CK活性及MDA含量B组显著低于A组（P＜0．05），结论：用HES行ANH对心肌缺血再灌注损伤具有保护作用。     

An in vitro method for predicting the efficacy of WBC separation using different starch preparations and anticoagulant ratios

BACKGROUND: Separation of blood components depends on a number of factors, including the viscosity of the plasma and the number and size of the various cellular elements. To enhance granulocyte collection, it is common practice to alter the plasma environment by the addition of sedimenting agents such as hydroxyethyl starch. Recently, because of its prolonged persistence in the circulation, the higher-molecular-weight form of hydroxyethyl starch, Hespan (HP), has been replaced by the lower-molecular-weight form, pentastarch (PS). However, the yield appears to be lower. A rapid in vitro approach was used to permit comparison of the efficiency of separation of WBCs by the use of PS and HP and different ratios of anticoagulants that also alter the sedimenting characteristics of blood. STUDY DESIGN AND METHOD: Blood from individual persons was collected into sodium citrate at ratios of 1:8, 1:12, and 1:16. Samples were evaluated either before or after the addition of PS or HP and after centrifugation. RESULTS: The addition of HP increased the sedimentation rate to at least four times that of plasma (10.9 vs. 47.9 mm); PS approximately doubled the rate. Viscosity was altered by the introduction of either starch. These changes (ranging from a rate of 4.2 in HP with a 1:16 anticoagulant to 3.6 in PS with a 1:8 ratio of anticoagulant) reflected the anticipated effects of anticoagulant dilution and carbohydrate addition. Granulocyte recovery was highest, with a 1:12 anticoagulant ratio in all tests with HP producing the greatest yield (HP, 101%; PS, 89%; control, 78%). CONCLUSION: HP is far more effective than its lower-molecular-weight substitute PS in the generation of granulocytes in the buffy coat of whole blood. This method provides a simple, rapid, in vitro approach to evaluating the separating efficiency of solutions.     

羟乙基淀粉对失血性休克血管反应性的影响

目的 观察羟乙基淀粉（HEs）对失血性休克血管反应性的影响，并探讨其机制。方法 40只SD大鼠，雌雄不限，按照随机数字表法分为正常组、休克组、复方氯化钠（即林格液，SC）组、HES130／0．4组和HES200／0．5组，每组8只。股动脉放血至大鼠平均动脉压（MAP）为40mmHg（1mmHg=0．133kPa），维持30min后分别输注溶液，使MAP升至70mmHg，并维持60min；观察各用药组在60min内维持MAP70mmHg所需补液量。分别在休克前及休克30、60和90min静脉注射去甲肾上腺素（NE）2μg／kg，观察液体对NE升压反应的影响；取动脉血测定血浆一氧化氮（NO）和一氧化氮合酶（NOS）含量。结果各用药组之间维持MAP70mmHg所需补液量比较差异均有显著性（P均〈0．01），其中HES200／0．5组所需补液量最少，HES130／0．4组次之，SC组最多。休克90min时，HES130／0．4组、HES200／0．5组MAP升高幅度均明显高于SC组（P均〈0．05），血浆NO和NOS含量均明显低于SC组（P〈0．05或P〈0．01）。结论 HES130／0．4和HES200／0．5可通过降低血浆NO和NOS含量，从而改善休克大鼠的血管反应性。