低密度脂蛋白胆固醇自动分析法与计算法比较

目的:对低密度脂蛋白胆固醇两种测定方法进行比较,探讨两种方法的可靠性.方法:利用两种不同方法测定血脂(包括甘油三酯TG、总胆固醇TC)浓度不同受试者血中低密度脂蛋白胆固醇(LDL-C)的含量,并绘制两种方法的相关图.结果TG和TC均在合适水平时,两种方法相关性较好.TG>4mmol/L时,计算结果高于测定值.结论:有条件实验室应采用自动分析法测定血中低密度脂蛋白胆固醇(LDL-C)的含量,为临床医生提供准确、可靠的诊断依据.     

不同饮食处方对高低密度脂蛋白胆固醇血症患者干预有效性评价

目的 探讨碳水化合物、蛋白质和脂肪3种不同比例的饮食处方对高低密度脂蛋白胆固醇(LDL-C)血症患者干预的有效性.方法 选取北部战区总医院自2018年1月至2019年12月收治的132例高LDL-C血症患者为研究对象.采用随机数字表法将其分为平衡营养组(碳水化合物:蛋白质:脂肪=5:2:3)、碳水化合物控制组(碳水化合...     

酶法直接测定血清中低密度脂蛋白胆固醇与Friedewald公式计算结果间的比较

低密度脂蛋白胆固醇在心血管疾病,尤其是动脉粥样硬化的形成中起了关键的作用,其中胆固醇含量的多少尤为重要,现已成为该类疾病诊断,疗效,及预后的重要指标。因此,有必要找到一种测定低密度脂蛋白胆固醇的可靠的常规方法。以往介绍的超速离心法,电泳法及聚乙烯硫酸沉淀法等方法虽准但不能满足临床生化常规检验的要求,而很多临床实验室采用了Friedewald公式计算法。但临床医生反映该公式所得结果常与患者临床资料不符。为此,我们运用一种目前较成熟的酶法测定血清中的LDL-C,对Friedewald公式在临床常规检验中的实用性作了评价。     

低密度脂蛋白胆固醇与高血压患者白质高信号损害程度关系的研究

目的 探讨低密度脂蛋白胆固醇(LDL-C)与高血压患者白质高信号(WMH)损害程度的关系。方法 搜集747例WMH患者,均来自本院的一项横断面研究,所有患者均采集详细病史及完成头颅MRI及血脂、血糖等检查和检验。采用改良的Fazekas评分方法评估WMH损害程度。结果 依据LDL-C对高血压和非高血压患者WMH损害程度进行多因素Logistic回归亚组分析显示,当LDL-C≥3.10 mmol/L时,高血压组WMH损害程度显著高于非高血压组(OR=10.88,95%CI 4.01～29.52,P<0.001);当LDL-C<3.10 mmol/L时,高血压组与非高血压组WMH损害程度无统计学意义(P=0.139)。结论 LDL-C水平与高血压患者WMH损害程度相关,当LDL-C≥3.10 mmol/L时,明显增加高血压患者WMH损害程度的风险。     

胆固醇代谢标志物的研究现状

大量流行病学研究和临床研究均支持低密度脂蛋白胆固醇(LDL-C)水平升高是动脉粥样硬化发生发展的重要危险因素之一.国际和国内血脂异常防治指南一致推荐LDL-C水平达标是防治冠心病的首要目标.但我国目前血脂控制状况不容乐观.     

脑梗死患者血清同型半胱氨酸与小而密低密度脂蛋白胆固醇的关系

目的探讨血清同型半胱氨酸(Hcy)水平升高和小而密低密度脂蛋白胆固醇(sdLDL-C)水平在脑梗死发病中的作用。方法采用全自动生化分析仪检测124例脑梗死患者血清Hcy和sdLDL-C水平,同时检测血清总胆固醇、三酰甘油、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇、血糖水平。根据头颅CT和磁共振检查证实后将患者分为多发性脑梗死组与单发性脑梗死组,观察其与Hcy及sdLDL-C的关系。结果脑梗死组血清Hcy及血脂水平明显高于对照组(HDL-C低于对照组),P<0.05,Hcy与sdLDL-C水平随脑梗死病变程度增加而升高(P<0.05)。Hcy和sdLDL-C与脑梗死病变程度密切相关(r=0.259和r=0.452,P<0.001)。结论 Hcy和sdLDL-C均是脑梗死发病的独立危险因素。     

直接测定法与间接计算法测得的HCO_3~-的比较

<正>HCO3-测定方法主要有两种:直接测定法和间接计算法,前者是取静脉血利用酶耦联反应直接测定,后者是取动脉血利用血气分析中得到的pH及CO2分压值计算得到。2010年5月—2011年6月,我们对同一患者血样,同时进行直接测定法和间接计算法检测HCO3-,共2 236份。直接测定法使用的仪器为OLYMPUS AU640全自动生化分析仪,间接计算法使用的仪器为i-STAT血气分析仪。结果两组数据回归方程为:y(测定值)=0.96x(计算值)+0.68     

胱抑素C、同型半胱氨酸、超敏C反应蛋白、总胆固醇、低密度脂蛋白胆固醇与急性脑梗死的关系

目的：观察急性脑梗死血清胱抑素C（CysC）、同型半胱氨酸（Hcy）、超敏C反应蛋白（hs-CRP）、总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）的浓度水平变化。方法检测2012年11月~2013年10月收治的急性脑梗死患者31例空腹CysC、Hcy、hs-CRP、TC、LDL-C的浓度水平;以同期健康体检者30例为对照组,比较两组间各项指标的差异,并进行统计分析。结果脑梗死组CysC、Hcy、hs-CRP、TC、LDL-C的浓度明显高于对照组,两组间比较差异有统计学意义（P〈0.05）。经logistic回归分析发现,CysC、Hcy、hs-CRP、TC、LDL-C是脑梗死的危险因素（OR值分别为1.036、1.664、1.484、1.241、1.070）。结论 CysC、Hcy、hs-CRP、TC、LDL-C的水平与急性脑梗死密切相关,可能是脑梗死的危险因素,监测并适当干预具有重要临床价值。     

人低密度脂蛋白受体检测方法的建立

肝脏是脂肪代谢的主要器官 ,肝细胞表面的低密度脂蛋白受体 (LDLR)是一种细胞膜表面糖蛋白 ,主要的生物学功能是介导低密度脂蛋白 (LDL)进入细胞 ,调节胆固醇的代谢 ,在脂肪代谢中起重要作用。LDLR突变能严重影响体内脂肪代谢 ,从而诱发家族性高胆固醇血症 ,能导致未成年期冠状动脉硬化。由于高血脂而导致的各种疾病是现代社会人类健康的重大威胁 ,因此 ,细胞表面LDLR的检测对于明确高血脂的病因和确定相应的治疗方法具有重要的临床指导价值。人LDLR转基因小鼠对于研究遗传性家族性高胆固醇血症的致病机制具有重要意义。本实验中用…     

不同水平低密度脂蛋白胆固醇对急性ST段抬高型心肌梗死患者冠状动脉病变影响研究

目的 探讨不同水平低密度脂蛋白胆固醇（LDL-C）对急性ST段抬高型心肌梗死（STEMI）患者冠状动脉病变的影响。方法 选取北部战区总医院自2017年1月至2018年12月收治的1 620例行急诊冠状动脉造影的STEMI患者为研究对象。依据入院LDL-C水平将其分为A组（LDL-C <1.8 mmol/L,n=112）与B组（LDL-C≥1.8 mmol/L,n=1 508）。记录并比较两组患者的临床资料与冠状动脉病变情况。采用多因素Logistic回归分析分析LDL-C与STEMI患者多支病变的相关性。使用受试者工作特征（ROC）曲线确定LDL-C预测STEMI患者多支病变的最佳界值,并在多因素Logistic回归分析模型中验证该界值是否为多支病变的独立危险因素。结果 A组患者年龄、陈旧性心肌梗死、既往经皮冠状动脉介入治疗史、脑卒中、入院时合并贫血比例、肌酐水平均高于B组,入院时血压、血清总胆固醇、甘油三酯、高密度脂蛋白胆固醇、纤维蛋白原、血小板、血红蛋白水平均低于B组,差异均有统计学意义（P <0.05）。B组患者靶病变血管为前降支发生率高于A组,靶病变血管为右冠状动脉...     

Radiotracers for low density lipoprotein biodistribution studies in vivo: technetium-99m low density lipoprotein versus radioiodinated low density lipoprotein preparations

In an attempt to characterize the in vivo behavior of [99mTc] low density lipoprotein (LDL), biodistribution studies were performed in normal and hypercholesterolemic (HC) rabbits. In normal rabbits, 24 hr after the injection of [99mTc]LDL, 99mTc activity accumulated mainly in adrenal glands, spleen, liver, and kidney. In HC rabbits, however, there was a marked reduction of 99mTc activity in these organs. In both normal and HC rabbits, less than 17% of 99mTc activity appeared in the 24-hr urine following injection of [99mTc]LDL, suggesting that in vivo, [99mTc]LDL is trapped and accumulated within the tissues. Direct comparison of [99mTc]LDL, 125I-native-LDL and [131I]tyramine cellobiose-LDL (the previously validated trapped radioligand) in normal rabbits, demonstrated that the biodistribution of [99mTc]LDL was similar to that of [131I]tyramine cellobiose-LDL. The adrenal glands, liver, and spleen accumulated significantly greater quantities of 99mTc and 131I activity per gram of tissue than 125I (from native-LDL). In addition, imaging studies in monkeys, showed that the hepatic uptake and retention of [99mTc] LDL was similar to that of [131I]tyramine cellobiose LDL. In contrast, radioiodine from native-LDL was deiodinated in liver with subsequent excretion into the intestine. These results suggest that [99mTc]LDL acts as a trapped ligand in vivo and should therefore, be a good tracer for noninvasive quantitative biodistribution studies of LDL.     

Chronic low level physical activity as a determinant of high density lipoprotein cholesterol and subfractions

Physical activity has been associated with reduced risk of coronary heart disease. A mechanism for the reduced risk may be through increased high density lipoprotein cholesterol (HDL-C) and subfractions, in particular HDL2-C. Research associated with increased physical activity investigating HLD-C have assessed the effects of intense aerobic activity. The current research evaluated the relationship between low intensity, long duration activity to HDL-C and subfractions in 35 active postal carriers. Measurements of physical activity via the Large Scale Integrated monitor and reported miles walked, and lipoproteins were assessed at 3-month intervals over a 1-year period. Reported miles walked/day (5.3) was significantly correlated with HLD2-C (r = 0.50, P = 0.003) and approached significance for HDL-C (r = 0.29, P = 0.06). The Large Scale Integrated measures were correlated with HDL-C (r = 0.44, P = 0.008) and HDL2-C (r = 0.44, P = 0.007). Controlling for either age, alcohol consumption, body mass index, or leisure time activity did not reduce the relationship between reported miles walked or Large Scale Integrated readings and HDL2-C, suggesting that the increased HDL-C was the result of long duration, low intensity physical activity.     

Effects of acute exercise on high density lipoprotein cholesterol and high density lipoprotein subfractions in moderately trained females

Increases in high density lipoprotein cholesterol (HDL-C) levels have previously been reported after moderate exercise bouts lasting less than two hours in men. Little information exists, however, on HDL-C responses after moderate duration exercise in women. Post-exercise HDL- C modifications may appear differently in women because of higher baseline HDL-C concentrations and differences in lipolytic activity. To determine the influence of exercise on acute HDL-C responses in women, 12 trained premenopausal women (22 (4) years old; mean (SD)) who ran 24- 48 km a week exercised on a motor driven treadmill at 75% VO2MAX until 3.34 MJ (800 kcal) were expended (72 (9) min). Subjects were all tested during the early follicular phase of their menstrual cycle. Fasting blood samples were obtained before exercise (baseline), immediately after (IPE), one hour after (1 h PE), 24 hours after (24 h PE), and 48 hours after (48 h PE) exercise. Plasma was analysed for HDL-C, HDL2-C, and HDL3-C. A significant increase in HDL-C was observed 48 h PE (p<0.05). HDL3-C increased IPE (p<0.01) but returned to baseline at 1 h PE. In contrast, HDL2-C was not significantly different from baseline at any time point. The rise in HDL-C, however, was attributed to an increase in both HDL2 and HDL3. Moreover, at 48 h PE, the increase in HDL-C correlated highly with changes in HDL2-C (r = 0.92). Thus it appears that exercise of moderate duration can elicit similar post- exercise increases in HDL-C in women to those previously reported in men. However, the changes in HDL subfractions leading to the rise in HDL-C may be different in women.


     

Studies of the accuracy of measurements of serum high density lipoprotein cholesterol levels

Titration of serum lipoproteins with three different precipitants--heparin-MnCl2 92 mmol.L-1, dextran sulfate-MgSO4, and phosphotungstate-MgCl2--revealed gross errors in the high density lipoprotein cholesterol (HDL-C) levels measured in some hyperlipidemic sera. Dilution studies of eight normal sera with the phosphotungstate method revealed that the most reliable estimate of the HDL-C level was the level measured in the least diluted aliquot that yielded a good precipitate. With a heparin-MnCl2 kit, serial dilution of a lipemic serum demonstrated a requirement for a blank correction. Establishing an accurate estimate of the HDL-C level sometimes requires knowledge of the titration curve of the lipoprotein precipitant being used, a blank correction, and data obtained from dilution studies (or studies with increased precipitant levels) on the serum in question.     

Radioiodinated peptide probe for selective detection of oxidized low density lipoprotein in atherosclerotic plaques

IntroductionDespite the significant effort in developing radioprobes for atherosclerosis, few have low molecular weight. Oxidized LDL (OxLDL), a highly proinflammatory and proatherogenic factor that is abundant in atherosclerotic plaques, plays a pivotal role in plaque destabilization, which makes OxLDL a relevant probe target. We developed a radioiodinated short peptide, AHP7, as a low molecular weight probe for specific OxLDL imaging and evaluated its utility using myocardial infarction-prone Watanabe heritable hyperlipidemic rabbits (WHHLMI).Methods[¹²⁵I]AHP7 was designed and synthesized based on the sequence of Asp-hemolysin, an OxLDL binding protein extracted from Aspergillus fumigatus. In vitro binding studies with OxLDL having varying degrees of oxidation were performed. Radioactivity accumulation in the aorta was measured 30 min post-administration in rabbits. Autoradiography and histological studies were performed using serial aorta sections. A radioiodinated scrambled peptide ([¹²⁵I]AHP scramble) was used as a negative control.Results[¹²⁵I]AHP7 bound to OxLDL in proportion to the degree of oxidation (R = 0.91, P < 0.0001) and was inhibited by unlabeled AHP7 in a concentration-dependent manner. The aorta accumulation level and aorta/blood and aorta/muscle ratios of [¹²⁵I]AHP7 in WHHLMI were 2.8-, 1.3- and 1.8-fold higher, respectively, than those in control rabbits (P < 0.001). Co-administration of AHP7 significantly reduced [¹²⁵I]AHP7 radioactivity in aorta sections (P < 0.0001). Regional radioactivity levels in the aorta sections showed nonuniformity but similarity to the immunohistochemical OxLDL density.ConclusionsThe potential of radioiodinated AHP7 for selectively imaging OxLDL was demonstrated both in vitro and in vivo.     

镍钛合金裸支架对内皮细胞低密度脂蛋白穿胞影响的初步研究

目的探讨镍钛合金裸支架是否影响低密度脂蛋白（LDL）在人脐静脉内皮细胞（HUVEC）中的穿胞并初步探讨可能的机制。 方法①培养HUVEC,利用细胞培养小池模拟血管内皮单层细胞,建立穿胞模型;②将镍钛合金裸支架作用于HUVEC上,加入异硫氰酸荧光素（FITC）标记的LDL,分别培养3 h及24 h;③通过测定培养小池内外FITC-LDL的量,研究镍钛合金裸支架对LDL在HUVEC中穿胞过程的影响。 结果3 h及24 h时镍钛合金裸支架作用下LDL在HUVEC中的穿胞量均增加。 结论在LDL和HUVEC构建的穿胞模型实验中,镍钛合金裸支架可以促进LDL的穿胞。     

血清胆红素、尿酸、低密度脂蛋白与冠心病的关系

目的探讨血清胆红素、尿酸(UA)、低密度脂蛋白(LDL-C)在冠心病(CHD)发生发展中的意义。方法选择我院心内科进行冠状动脉造影检查确诊的32例冠心病患者作为观察组,32例健康体检成人作为对照组。测定血清总胆红素(TBIL)、直接胆红素(DBIL)、间接胆红素(IBIL)、UA、LDL-C指标并分析与冠心病的关系。结果与健康对照组相比,CHD组UA、LDL-C水平均显著升高(P<0.01),而TBIL、DBIL水平均显著下降(P<0.01),IBIL虽有下降但差异无统计学意义(P>0.05)。结论胆红素、UA、LDL-C可能相互影响参与冠心病的发生与发展,早期干预有可能预防心血管事件的发生。     

人LDLR基因的克隆及在Hepa1-6细胞中的表达

目的 :从能感染HCV的人肝癌细胞HepG2中克隆出人LDLR基因 ,构建其真核表达质粒 ,并在小鼠肝癌细胞Hepa1 6中进行表达。方法 :从HepG2中提取总RNA ,采取逆转录PCR(RT PCR)方法得到人LDLR的cDNA。将获得的人LDLR基因克隆到真核表达载体pcDNA3中 ,进行酶切和序列鉴定。将重组质粒pcDNA3 hLDLR和空载体转入Hepa1 6 ,G4 18筛选 ,并用RT PCR和FACS检测人LDLR基因转录和蛋白的表达。结果 :人LDLR的cDNA已插入载体pcDNA3构建成真核表达质粒pcDNA3 hLDLR ,双酶切和测序表明 ,克隆的人LDLR与已登录GenBank的序列存在核苷酸多态性 ,但编码的氨基酸序列完全一致 ,该序列的GenBank登录号为gi|2 16 2 96 4 7|gb|AY114 15 5 .1,并且真核表达质粒的构建正确。用脂质体介导的方法转入Hepa1 6后 ,用RT PCR和FACS检测表明 ,细胞可表达人LDLR。结论 :成功地构建了真核表达质粒pcDNA3 hLDLR ,为进一步研究HCV和人LDLR的相互作用 ,以及建立可能的HCV细胞感染模型奠定了基础。