大豆蛋白降低人体血浆胆固醇浓度的作用途径

背景:多项实验表明同酪蛋白相比,大豆蛋白在动物包括人体内可以降低血浆胆固醇浓度,但其作用途径尚未阐明。目的:探讨摄入大豆蛋白后,人体血浆胆固醇浓度降低的可能作用途径。设计:观察对比实验。单位:沈阳医学院预防医学系营养与食品卫生学教研室。对象:实验于2002-03/05在沈阳医学院预防医学系营养与食品卫生学实验室完成。选择沈阳医学院健康大学生20名,男女各半,均自愿参加实验,并得到签名的书面同意书。年龄(21±1)岁,体质量指数为(22.3±3.0)kg/m2,血浆总胆固醇浓度在正常范围。将实验对象分为两组,既酪蛋白组和大豆蛋白组,每组10名。方法:依据中国营养学会1999年制定的《中国居民平衡膳食宝塔》和学生餐厅食谱编制基础膳食食谱。在摄入相同基础膳食的基础上,酪蛋白组和大豆蛋白组每人摄入酪蛋白和大豆蛋白30g/d,共摄入14d。在实验开始和结束时,测量两组实验对象的体质量,并采血测定血浆总胆固醇浓度;在实验结束前3d,收集每人的粪便,测定粪钙、磷、镁、脂类和胆汁酸含量,并进行比较分析。主要观察指标:①两组实验对象实验期间血浆总胆固醇浓度。②两组实验对象实验期间粪钙、磷、镁、脂类和胆汁酸排出量及相关和回归分析结果。结果:大豆蛋白组1名实验对象由于交通事故退出实验,酪蛋白组1名实验对象因对酪蛋白不耐受退出实验。两组均有9名实验对象进入结果分析。①两组实验对象实验期间血浆总胆固醇浓度比较:与实验开始时相比,实验14d后酪蛋白组血浆总胆固醇浓度升高了11%犤(3.7±0.47,4.1±0.61)mmol/L(Z=-2.668,P<0.01)犦,而大豆蛋白组仅升高了6%(P>0.05)。②两组实验对象实验期间粪钙、磷、镁、脂类和胆汁酸排出量比较:同酪蛋白组相比,大豆蛋白组的粪钙、磷和镁的排出量均明显增加,分别增加了60.3%,44.1%和55.0%(P<0.05～0.01);粪脂类和胆汁酸分别增加了33.6%和45.3%。③相关和回归分析:粪胆汁酸排出量同粪钙、磷、镁和脂类排出量呈显著正相关(t=3.173,3.448,2.411,2.122,P<0.05)。结论:大豆蛋白降低人体血浆胆固醇浓度的可能途径是增加了粪钙、磷、镁和胆汁酸的排出量。     

肌酐和总胆固醇试剂对总胆汁酸测定结果的影响探析

目的探讨肌酐(Cr)和总胆固醇(TC)试剂对总胆汁酸(TBA)测定结果的影响。方法该研究就TBA自动分析出现交叉污染的项目及制定的解决方法进行分析。结果 TBA测定中,TC试剂和Cr试剂对其结果有正干扰,TBA的测定结果在先对TC和Cr测定后再行TBA分析下受到的影响较为明显,再TBA测定结果中,先对Cr进行测定其影响可向第2管持续,而在对TBA的测定中,先测TC其影响持续可达到第4管。结论结合TBA测定中,TC和Cr对其结果正干扰影响进行分析,对生化分析仪行模块式操作可将被干扰的项目的和干扰的项目在不同模块中安排,同时加强防范措施,以从根本上降低交叉感染发生率,为临床检验的准确性提供有力的保障。     

正常孕妇血清总胆汁酸浓度观察

目的 观察正常早、中、晚期孕妇血清总胆汁酸（TBA）浓度变化。方法采用总胆汁酸第5代循环酶法测定我院92例健康妇女血清和299例正常孕妇血清,用全自动生化分析仪测定血清总胆汁酸。结果健康妇女92例血清TBA平均值为（3．6&#177;1．7）μmol／L;早期孕妇96例血清TBA平均值为（4．4&#177;1．9）μmol／L;中期孕妇104例血清TBA平均值为（5．8&#177;2．0）μmol／L;晚期孕妇99例血清TBA平均值为（6．9&#177;2．1）μmol／L;健康妇女组与早期孕妇组比较差异有统计学意义（P〈0．05）;健康妇女组与中期孕妇组、晚期孕妇组比较差异有统计学意义（P〈0．01）;早期孕妇组与中期孕妇组、晚期孕妇组比较差异有统计学意义（P〈0．01）;中期孕妇组、晚期孕妇组比较差异有统计学意义（P〈0．01）。结论正常早、中、晚期孕妇血清TBA具有上升趋势且各期有显著性差异,应建立早、中、晚期孕妇血清TBA测定的正常参考值。     

摄入不同剂量大豆蛋白干预高胆固醇模型大鼠的血脂水平

目的:探讨膳食大豆蛋白摄入的不同剂量和时程对高血浆胆固醇模型大鼠血清胆固醇及有关血脂指标的影响。方法:实验于2004-02/05在沈阳医学院预防医学系进行,用含50g/kg猪油,10g/kg胆固醇和2.5g/kg胆盐的高脂饲料喂饲健康Wistar雄性大鼠,经2周诱发高血浆胆固醇以后,测血清总胆固醇,总三酰甘油,高密度脂蛋白胆固醇和低密度脂蛋白胆固醇浓度。然后,按体质量和血清胆固醇浓度均衡的原则,将36只动物随机分为4组,分别喂饲含有200g/kg大豆蛋白、200g/kg酪蛋白、300g/kg大豆蛋白和300g/kg酪蛋白的纯合成高脂饲料,并于实验第4周和第8周结束时采血,测定指标同前。实验结果用SPSS统计软件进行方差分析。结果:经2周诱导高血脂后,实验模型大鼠的血清总胆固醇水平为(4.55±1.25)mmol/L(n=36),而喂饲正常饲料的阴性对照鼠仅为(2.30±0.18)mmol/L(n=8),升高了近2倍。又经4周喂饲含有处理因素的饲料后,200g/kg大豆蛋白组、200g/kg酪蛋白组、300g/kg大豆蛋白组和300g/kg酪蛋白组大鼠的血清总胆固醇水平分别为(2.51±0.31),(3.45±0.67),(2.59±0.22),(3.67±0.87)mmol/L;低密度脂蛋白胆固醇为(1.21±0.16),(1.67±0.32),(1.25±0.10),(1.78±0.43)mmol/L,与同水平酪蛋白组相比,大豆蛋白组动物的血清总胆固醇,低密度脂蛋白胆     

胆汁酸的毒性作用

胆汁淤积发生后导致胆汁酸在肝脏和血液中潴留,而胆汁酸有多种毒性作用,包括细胞毒作用及急、慢性毒性作用,造成肝损伤及全身多系统、多器官损害,最终导致肝硬化、肝功能衰竭和死亡。胆汁酸的毒性作用在胆汁淤积所致肝脏损害的病理过程中起重要作用。现对国内外的相关文献进行综述,探讨胆汁淤积的危害。     

乙型肝炎病毒携带者血清总胆汁酸、前白蛋白浓度的观察

目的观察乙型肝炎病毒携带者血清总胆汁酸（TBA）、前白蛋白（PALB）的浓度。方法将、365例血清标本在7180全自动生化分析仪上同时检测TBA、PALB，进行分组统计阳性率。结果乙型肝炎病毒携带者小三阳组TBA阳性率为11．5％，PALB阳性率为6．2％，TBA＋PALB阳性率为1．8％；乙型肝炎大三阳TBA阳性率为20．0％，PALB阳性率为10．5％，TBA＋PALB阳性率为5．3％。结论建议乙型肝炎病毒携带者检查常规肝功生化项目时同时检测TBA、PALB，以了解肝脏合成功能和实质性损伤情况，在该病的治疗观察和预后判断方面有一定临床应用价值。     

血清总胆汁酸测定的结果分析

胆汁酸是胆固醇在肝脏分解代谢的产物，它由肝脏分泌到胆汁中，并随胆汁排入肠腔，作用于脂肪的消化和吸收。健康人肝细胞能有效地从血液中摄取胆汁酸，因此循环血液中胆汁酸含量很微。当肝细胞受损时，不能有效地回吸收胆汁酸，或胆道排泄不畅，胆汁酸不能有效地排出，都可能使血液中胆汁酸增高。由于其生成和代谢与肝脏有十分密切的关系，故测定血清总胆汁酸（TBA）可提供肝胆系统正常与否的重要信息。它不仅用于临床诊断，还能反映病情发展和评估预后。本文对各种疾病组206例患者的TBA及ALT进行了分析比较，现将结果报告如下。     

复合膳食纤维对大鼠脂代谢的长期作用及其机制

目的:观察复合膳食纤维B(dietary fiber complex B,DFC-B)对大鼠脂代谢的长期作用及可能的作用机制。方法:健康SD大鼠84只,诱导成高脂血症模型后按体质量及血胆固醇均衡的原则分为7组,以基础及高脂饲料作为对照组,其余5组给不同水平的DFC配方B,实验期3个月,观察DFC对大鼠血脂、肝脂水平以及粪胆汁酸排泄的长期影响。 结果:与高脂组相比,大鼠血TC在不同水平的DFC组均显著降低,差异有显著性意义(P<0.05)。DFC可以长期有效地降低大鼠肝胆固醇的水平(mmol/L)(0.42±0.12～2.20±1.02和3.26±0.16,P<0.05)。不同水平DFC均能增加大鼠粪胆汁酸的排泄,并存在明显的量效关系,但长期食用较高剂量DFC会减少大鼠粪胆汁酸的排泄量。 结论:DFC确能长期有效地降低血浆胆固醇水平,减少肝胆固醇的沉 积,增加粪胆汁酸的排泄是DFC降低血胆固醇的机制之一。     

设置特殊清洗程序消除试剂携带污染对总胆汁酸测定的干扰

目的 已知总胆固醇和肌酐的酶法测定试剂对循环酶法测定总胆汁酸（TBA）有干扰,研究探讨在全自动生化分析仪上采用设置特殊清洗程序消除因试剂携带污染对TBA测定的干扰的方法。方法 在HITACHI7600生化分析仪上设置特殊清洗程序,在TBA试验项目加试剂前对仪器试剂针和固定比色杯自动清洗后再进行特殊清洗,以消除因试剂携带污染对TBA测定的干扰;并对设置与未设置特殊清洗程序的TBA测定结果进行比较,以观察特殊清洗的效果。结果 设置与未设置特殊清洗状态下,测定TBA结果,比较其差异有统计学意义。配对t检验：t值在-3．6205～-4．8751之间,P值在0．0001-0．0006之间。结论 设置特殊清洗方式可有效地消除因试剂携带污染对TBA测定的干扰。     

126例ALT增高精神病患者总胆汁酸的测定分析

目的探讨抗精神病药物所致肝损害时总胆汁酸的变化以及在用药安全监测中的应用价值。方法选择符合《中国精神障碍分类和诊断标准》第三版（CCMD-3）精神病诊断标准，排除躯体性疾病，肝功能监测ALT增高（ALT040U／L）精神科住院病例126例，测定其血清总胆汁酸，并与11例肝病患者和23例健康体检者进行对照分析。结果126例ALT增高精神病患者总胆汁酸水平无明显变化（6．70&#177;9．12umol／L），与健康对照组（4．99&#177;3．05umol／L）比较，差异无统计学意义（P〉0．05），与肝病组（62．35&#177;36．43umol／L）比较差异有统计学意义（P〈O．01），126例精神病患者中有6例TBA轻度增高（18．6&#177;4．4umol／L），异常率为4．8％（6／126），与肝病组比较差异有统计学意义（P〈0．01），健康对照组无1例异常，异常率为0（0／23），肝病组全部异常，异常率为100％（11／11）。结论总胆汁酸在抗精神病药物安全监测中不如转氨酶指标敏感，但在判定肝细胞损害程度及预后有重要临床意义。     

In cholesterol lowering, moderation kills

The high-fat American diet is responsible for an epidemic of coronary artery disease. A plant-based diet with less than 10% fat will prevent coronary disease from developing, halt the progress of existing disease, and even reverse the disease in many patients. Given proper support and education, motivated patients with a history of coronary disease can follow this diet and prevent future cardiac events.     

New guidelines for lowering blood cholesterol

An expert panel of the National Cholesterol Education Program issued a report that presents new, detailed guidelines for cholesterol treatment. The report provides specific recommendations for classifying patients according to their cholesterol levels. By using these guidelines, physicians dealing with individual patients will be able to determine who should be treated to lower blood cholesterol and to decide how such patients should be treated.     

Ezetimibe: cholesterol lowering and beyond

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol. It appears to exert its effect by blocking intestinal sterol transporters, specifically Niemann–Pick C1-like 1 proteins, thereby inhibiting the intestinal absorption of cholesterol, phytosterols and certain oxysterols. Ezetimibe monotherapy and in combination with statin therapy is primarily indicated for lowering LDL-cholesterol levels. In addition, it may favorably affect other parameters that could potentially further reduce atherosclerotic coronary heart disease risk, such as raising HDL-cholesterol and lowering levels of triglycerides, non-HDL-cholesterol, apolipoprotein B and remnant-like particle cholesterol. Further effects of ezetimibe include a reduction in circulating phytosterols and oxysterols and, when used in combination with statins, a reduction in high-sensitivity C-reactive protein. The clinical significance of the LDL-cholesterol lowering and other effects of ezetimibe is being evaluated in clinical outcome studies.     

Does cholesterol lowering prevent stroke?

The importance of lowering plasma cholesterol to reduce the incidence of conorary events is well established. However, in the prevention of stroke disease, control of hypertension has been the main aim of treatment and lipid lowering therapy has not hitherto been considered to be desirable or necessary. In this review, the evidence from large multicentre trials, imaging studies and meta-analyses is presented. It shows convincingly that HMG-CoA reductase inhibitors (Statins) reduce stroke risk.     

Fluvastatin: effects beyond cholesterol lowering

Coronary heart disease (CHD) remains a major therapeutic challenge in the Western world, and strategies aimed at cholesterol lowering form the mainstay of treatment. Fluvastatin is an established 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor ("statin") for the treatment of hypercholesterolemia. Its efficacy and safety have been established in numerous clinical trials. Emerging evidence now indicates that treatment with fluvastatin slows the progression of atherosclerotic CHD and reduces the incidence of cardiovascular morbimortality in the secondary prevention setting. This effect of fluvastatin cannot be explained by cholesterol lowering alone; nonlipid-related mechanisms (so-called "pleiotropic effects") undoubtedly contribute to a certain extent, and are probably linked to modulation of the mevalonate pathway. This review discusses the experimental evidence regarding the antiatherosclerotic and antithrombotic effects of fluvastatin that may contribute to its beneficial action on disease progression and clinical events. Such effects include decreased expression of adhesion molecules in monocytes and leucocyte-endothelium adherence responses, immunomodulation, prevention of low-density lipoprotein oxidation, inhibition of cholesterol esterification and accumulation, along with effects on smooth muscle cell proliferation and migration. Pleiotropic actions aimed at plaque stabilization (eg, decreased secretion of matrix metalloproteinases by macrophages), together with effects on platelet activity, tissue factor expression, and endothelial function, may contribute to an antithrombotic effect of fluvastatin. Taken together, the results of these studies indicate that the effects of fluvastatin, at therapeutic doses, may extend beyond cholesterol lowering.     

Ezetimibe: cholesterol lowering and beyond

Ezetimibe is a cholesterol absorption inhibitor that blocks the intestinal absorption of both biliary and dietary cholesterol. It appears to exert its effect by blocking intestinal sterol transporters, specifically Niemann-Pick C1-like 1 proteins, thereby inhibiting the intestinal absorption of cholesterol, phytosterols and certain oxysterols. Ezetimibe monotherapy and in combination with statin therapy is primarily indicated for lowering LDL-cholesterol levels. In addition, it may favorably affect other parameters that could potentially further reduce atherosclerotic coronary heart disease risk, such as raising HDL-cholesterol and lowering levels of triglycerides, non-HDL-cholesterol, apolipoprotein B and remnant-like particle cholesterol. Further effects of ezetimibe include a reduction in circulating phytosterols and oxysterols and, when used in combination with statins, a reduction in high-sensitivity C-reactive protein. The clinical significance of the LDL-cholesterol lowering and other effects of ezetimibe is being evaluated in clinical outcome studies.     

Effect of tablet splitting on serum cholesterol concentrations

OBJECTIVE: To evaluate the effects of tablet splitting on low-density lipoprotein (LDL) cholesterol and total cholesterol values in patients taking simvastatin and atorvastatin. DESIGN: A retrospective chart review of total cholesterol and LDL cholesterol values of patients instructed to split simvastatin or atorvastatin between January 1999 and November 2000. SETTING: Veterans Affairs Medical Center in Huntington, WV. PATIENTS: Patients were included if they were taking simvastatin or atorvastatin with regular lipid management and follow-up laboratory results. Patients were required to remain on the same milligram-per-day dose at least 6-8 weeks before and after tablet-splitting initiation and have cholesterol values drawn at least 6 weeks after initiation of both whole-tablet and half-tablet dosing. Patients were excluded if they had a triglyceride level > 400 mg/dL or were noncompliant on the basis of pharmacy records and provider notes. MEASUREMENT OUTCOMES: The primary end points were changes in total cholesterol and LDL cholesterol values before and after the patient was switched to half-tablet therapy. RESULTS: The overall results for this review demonstrated no statistically significant increase in total cholesterol and LDL cholesterol concentrations. Total cholesterol and LDL cholesterol values actually decreased from presplitting to postsplitting, p = 0.017 and p = 0.003, respectively. CONCLUSIONS: The investigation showed that half-tablet dosing was as effective as whole-tablet dosing. The program will be continued as a part of quality patient care at the Huntington Veterans Affairs Medical Center.