重氮试剂消除胆红素对胆固醇酶法测定的干扰

应用酶法测定胆固醇 ,胆红素对结果有明显负干扰。我们在黄疸血清中先加入重氮试剂 ,使胆红素转化成偶氮胆红素后 ,再与胆固醇酶试剂反应显色 ,有效地消除了胆红素的影响。现介绍如下。1　材料与方法1 1　试剂　总胆固醇酶法测定试剂盒 (东瓯公司产品 )。咖啡因 苯甲酸钠试剂     

酶法测定血清甘油三酯能否消除游离甘油的影响

现有酶法测定试剂不能去除血清中的游离甘油,使甘油三酯值偏高.尽管反应系统中不存在脂蛋白脂酶,但随着样品和反应系统预孵育时间的延长,再加入脂蛋白脂酶后,甘油三酯的测定值逐渐下降.说明现有酶法测定系统不能扣除血清中游离甘油对甘油三酯测定的影响.     

钒酸盐氧化法消除胆红素对酶法测定胆固醇的干扰

目的探讨用钒酸盐氧化法消除胆红素对酶法测定胆固醇干扰的方法。方法选择含有不同胆红素血清标本,应用ALBK法、未消除胆红素酶法、消除胆红素酶法3种方法分别进行血清胆固醇浓度测定,用配对t检验及相关、回归归分析,比较3法结果差异及相关性。结果ALBK法与未消除胆红素酶法、未消除胆红素酶法与消除胆红素酶法,经配对t检验(t=0.289、0.325,两者P>0.05);相关性良好(r=0.9897、0.9910)。结论此方法操作简单,结果可靠,经济实用,能有效地消除胆红素对酶法测定胆固醇的负干扰。     

胆红素氧化酶法消除胆红素对酶法测定胆固醇的干扰

目的探讨用胆红素氧化酶法消除胆红素对酶法测定胆固醇的干扰。方法选择含有不同胆红素血清标本,应用ALBK法、未消除胆红素酶法、消除胆红素酶法3种方法分别进行血清胆固醇浓度测定,用配对t检验及相关、回归分析,比较3法结果差异及相关性。结果ALBK法与未消除胆红素酶法、未消除胆红素酶法与消除胆红素酶法,经配对t检验(t=0.338、0.341,两者P>0.05);相关性良好(r=0.9789、0.9901)。结论此方法操作简单,结果可靠,能有效地消除胆红素对酶法测定胆固醇的负干扰。     

用MTAB直接重氮盐法测定血清总胆红素

目前测定总胆红素主要有重氮试剂法和氧化法(化学氧化法和酶氧化法)两大类.在重氮试剂法中,以往都有临时制备重氮苯磺酸试剂的麻烦,且又不能保存.在反应的催化剂方面,二甲亚砜及某些非离子型表面活性剂的用量都较大,故粘性很高[1,2].据此我们直接使用稳定的重氮盐和加入少量的阳离子活性剂,建立了单试剂直接终点法测定血清总胆红素的方法,适用于自动分析或手工操作.     

钒酸盐氧化法消除胆红素对酶法测定高密度脂蛋白胆固醇的干扰探讨

目的:探讨用钒酸盐氧化法消除胆红素对酶法测定高密度脂蛋白胆固醇干扰的方法。方法:选择含有不同胆红素血清标本,应用磷钨酸-镁法、未消除胆红素酶法、消除胆红素酶法3种方法分别进行血清高密度脂蛋白胆固醇浓度测定,用配对t检验及相关、回归归分析,比较3法结果差异及相关性。结果:磷钨酸-镁法与未消除胆红素酶法、未消除胆红素酶法与消除胆红素酶法,经配对t检验(t=0.376、0.401,两者P>0.05);相关性良好(r=0.978 9、0.980 7)。结论:此方法操作简单,结果可靠,经济实用,能有效地消除胆红素对酶法测定高密度脂蛋白胆固醇的负干扰。     

血清结合胆红素酶法测定在自动生化分析仪上的应用

目的　建立酶法测定血清结合胆红素的全自动分析方法 ,并在肝胆疾病患者中临床应用。方法　通过试剂的合理组合 ,分析参数和操作程序的设定 ,建立结合胆红素 (CB)的全自动分析方法 ,同时对总胆红素进行自动化酶法测定。结果　酶法CB测定 :精密度 ,批内n =2 0 , x =6 .4 8μmol/L ,s=0 .11,CV =1.7%和n =2 0 , x =77.9μmol/L ,s=0 .4 2 ,CV =0 .5 3% ;批间n =10 , x =9.4 6 μmol/L ,s=0 .17,CV =1.83%和n =10 , x =5 9.7μmol/L ,s=1.4 3,CV =2 .39% ;线性范围至少可达 340 μmol/L ;比对实验 :与Beckman重氮法试剂 (在BeckmanCX7型生化分析仪上 )比较 ,Y(酶法 ) =0 .75 9X1- 2 .82、r =0 .991,与IagnosticumRT重氮法试剂 (日立 76 0 0 0 2 0型分析仪 )比较 ,Y =0 .84 1X2 - 4 .39、r=0 .96 3。临床研究显示 :与重氮法直接胆红素值相比 ,本法测定CB值能够更灵敏地反映黄疸患者的胆红素分泌功能。结论　建立的CB全自动分析方法具有良好的分析特性 ,可在临床推广应用。     

酶法测定血清甘油三酯能否消除游离甘油的影响

现有酶法测定试剂不能去除血甭中的游离甘油,便甘油三酯值偏高。尽管反应系统中不存在脂蛋白脂酶,但随着样品和反应系统顶育时间的延和再加入脂蛋白脂酶后,甘油三酯的测定值逐渐下降。说明现有酶法系统不能扣除血甭中游离甘油对甘油三酯测定的影响。     

重氮试剂对尿素自动化测定的影响及处理措施

目的 分析自动生化仪中重氮试剂对尿素测定是否存在交叉污染及其产生原因并提出解决方法.方法 用迈瑞BS-300全自动生化分析仪将新鲜混合血清单独进行尿素测定,然后将同份标本分别置于总胆红素(TB)或直接胆红素(DB)测试项目后再进行尿素测定,记录其结果并进行统计学分析;将重氮试剂一系列稀释作为标本来测定尿素,分析其对尿素自动化测定有无影响及影响程度.结果 重氮法原理中直接胆红素试剂对尿素测定结果没有影响,总胆红素试剂对尿素会产生明显的正干扰.结论 检验人员使用全自动生化仪时,不仅要熟悉仪器工作流程、试剂组成、测定原理等,更要注意试剂间的交叉污染,并根据仪器工作特点制定相应的措施来消除交叉污染,从根本上保证实验数据的可靠性,为临床提供客观真实的诊疗依据.     

钒酸盐氧化法消除胆红素对酶法测定甘油三酯的干扰探讨

目前测定甘油三酯（TG）的临床常用方法是酶法,其原理是利用Trinder反应,生成红色复合物,在500 nm处测定其吸光度的增加量计算TG的浓度.但此方法不能消除胆红素（Bil）的干扰,因为胆红素在500 nm处也有较强的光吸收,这样就掩盖了TG本身的显色反应,从而使测定结果偏低.我们利用钒酸盐氧化胆红素,使之转化成胆绿素,这种预处理能有效地消除胆红素对酶法TG测定的干扰.[第一段]     

A standardized triglyceride and carbohydrate challenge: the oral triglyceride tolerance test

OBJECTIVE: A standardized method of assessing postprandial triglyceride changes is not available. We evaluated an oral triglyceride tolerance test (OTTT) designed for routine clinical and research use. RESEARCH DESIGN AND METHODS: A 200-ml strawberry-flavored test drink (50 g fat, 50 g carbohydrate) was administered twice to 30 diabetic and 20 nondiabetic subjects. Venous plasma triglyceride and glucose levels were measured when fasting and every 2 h for 8 h after the drink. Fingerprick plasma triglyceride levels were measured when fasting and at 6 and 8 h after the drink. RESULTS: The drink was consumed within 3 min and well tolerated by all subjects. The median triglyceride rise at 6 h was similar in diabetic and nondiabetic subjects (0.23 vs. 0.42 mmol/l, NS) and correlated with glucose increase at 2 h (r = 0.429, P = 0.018 and r = 0.509, P = 0.026; respectively). Diabetic subjects had higher 6-h geometric mean (1 SD range) triglyceride levels (1.82 [1.87 to 3.23] vs. 1.11 [0.66 to 1.11 mmol/l], P < 0.003) but a similar coefficient of variation (17.5 vs. 17.0%, NS) and a similar median (interquartile range) time to achieve maximal concentration (T(max)) (6.0 [4.0 to 6.0] vs. 5.0 [4.0 to 6.0] h, NS). Capillary triglyceride values were equivalent to simultaneous venous samples but consistently 10% greater. CONCLUSIONS: The OTTT permits simple evaluation of postchallenge triglyceride levels, is acceptable to subjects, and can be performed with capillary sampling. It could be used to monitor triglyceride-lowering therapies and to provide additional information concerning cardiovascular disease risk, particularly in diabetic subjects.     

Inhibition of steady-state intestinal absorption of long-chain triglyceride by medium-chain triglyceride in the unanesthetized rat

Maximal steady-state intestinal absorption rates in unanesthetized rats for triolein, a long-chain triglyceride, and for trioctanoin, a medium-chain triglyceride, are known to differ. Both these lipids are hydrolyzed in the intestinal lumen but the products of hydrolysis are metabolized differently by the mucosal cell. Intraduodenal infusion of trioctanoin was found to reduce steady-state triolein absorption. Luminal lipolysis was shown not to be rate-controlling. High rates of trioctanoin infusion significantly lowered the pH of the luminal aqueous phase and altered the partition of oleic acid between aqueous and oil phases. Two possible mechanisms for the inhibition of triolein uptake are considered. In the intestinal lumen medium chain lipids might have lowered the activity of oleic acid monomers in the aqueous phase and reduced passive diffusion into mucosal cells. Alternatively, competition between long and medium chain fatty acids for some common receptor during transport into the intestinal mucosal cell may have occurred.Despite significant inhibition of triolein absorption by high levels of trioctanoin, the maximum number of calories absorbed from mixtures of triglycerides exceeded the maxima from either glyceride alone. The optimum proportion of triolein to trioctanoin in lipid infusion mixtures was about 3:4 by weight and the optimum dosages about half maximal for each triglyceride, which represented a caloric intake of 4 kcal/rat per 2 hr. The absorption coefficient for this lipid mixture was about 90%. It is suggested that in patients who have a limited intestinal absorptive capacity dietary fat intake might be doubled with a caloric supplement of medium-chain triglycerides without increase in steatorrhea of long-chain fat.     

Comparison of triglyceride concentration with lipemic index in disorders of triglyceride and glycerol metabolism.

BACKGROUND: In plasma, triglycerides (TG) are transported in lipoprotein particles (mainly chylomicrons, very low-density and low-density lipoprotein). Turbidimetry (bichromatically at 660 and 700 nm) allows measurement of the lipemic (L) index. We explored the use of this index, in combination with a TG assay, to detect errors due to non-fasting, to assess abnormalities in TG metabolism and to detect patients with glycerol kinase deficiency (GKD). METHODS: We collected 2441 patient samples. Normolipidemic (n=2347), type IV hyperlipidemic (n=80), postprandial samples (n=22) and serial dilutions of Intralipid with saline (n=6) were selected. One patient presenting with GKD was included, as well as two patients with type I and type V hyperlipoproteinemia, respectively. RESULTS: We introduced the use of the ratio between the logarithm of serum triglycerides and that of the L-index (TG/L ratio). CONCLUSION: Although the proposed TG/L-index ratio cannot be regarded as an alternative for the accurate diagnosis of lipid disorders, it provides additional information about TG-containing particles.     

Effect of fasting on two postheparin plasma triglyceride lipases and triglyceride removal in obese subjects.

A new method was used for selective measurement of lipoprotein lipase and hepatic lipase in human postheparin plasma. Hepatic lipase was assayed in 1.0 M NaCl withour addition of serum, and the activity of lipoprotein lipase was determined in 0.1 M NaCl after immunoprecipitation of hepatic lipase with specific antiserum. The activity of both these enzymes and the total lipolytic activity were measured in plasma samples taken during a 4-h infusion of heparin. Each of the activities was related to basal serum triglyceride concentration and to the fractional removal constant (K) of Intralipid in 13 obese subjects before and after prolonged fasting. During a normal isocaloric diet the lipolytic activities showed a biphasic response to heparin infusion in all subjects. A peak activity was reached within 30 minutes ("early response") and thereafter the lipase activities decreased to a constant level maintained during the rest of the heparin infusion ("late response"). The early response of lipoprotein lipase showed a significant inverse correlation with the basal serum triglyceride level (r = -0.85) and a significant positive correlation with the fractional removal rate of Intralipid (r = 0.84). The late response of lipoprotein lipase was not related to either of these parameters. The early response of hepatic lipase was not correlated with basal triglyceride concentration or Intralipid removal, whereas the late response of this enzyme showed a significant negative correlation with the removal rate of Intralipid (r = -0.82). After fasting for several days the acute response of all lipolytic activities to heparin was markedly decreased or totally abolished, but the magnitude of the late response was similar to that seen in the fed state. The fractional removal rate of Intralipid was slightly increased by starvation. All correlations between postheparin plasma lipases and serum triglyceride concentration and removal disappeared in fasting subjects. It is concluded that the rapidly releasable lipoprotein lipase probably reflects the activity of the tissue enzyme(s) which is responsible for the primary removal of very low density lipoprotein (VLDL) triglycerides and chylomicrons. It is probable that this component of the postheparin plasma lipolytic activity is derived from the endothelial lipoprotein lipase pool. This enzyme plays a key role in the efflux of plasma triglycerides under normal conditions, and it is thus one determinant of plasma triglyceride level. Prolonged fasting obviously changes the triglyceride removal sites and mechanism but does not impair the removal efficiency.     

Plasma triglyceride metabolism in thyroid disease

Plasma endogenous triglyceride transport kinetics were determined in 16 hyperthyroid and in 12 hypothyroid patients and the results compared with those of euthyroid control subjects. In addition, the removal of exogenous particulate fat (Intralipid; Vitrum, Sweden) from the circulation and the postheparin plasma lipolytic activity (PHLA) were studied in these patients for further characterization of the alterations of plasma triglyceride metabolism in thyroid disease.In thyrotoxicosis the average plasma triglyceride level was slightly but significantly increased above that of control subjects. This change was associated with augmented production of triglycerides whereas the mean fractional removal rate was not different from normal. There was a significant linear correlation between the concentration and turnover rate of plasma triglycerides in both hyperthyroid and euthyroid subjects but the concentration/turnover rate ratio was less in the former group suggesting that the efficiency of removal of triglycerides from the circulation was improved in thyroid hyperfunction. The elimination of intravenously administered particulate fat occurred more rapidly in untreated hyperthyroid patients than in euthyroid control subjects. The mean PHLA was also above normal in thyrotoxicosis. Upon adequate treatment of the hyperthyroid state the fasting plasma triglyceride concentration was further increased.Hypothyroid patients showed another pattern of alteration of triglyceride kinetics. The synthesis of plasma triglycerides was normal but the fractional removal of both endogenous and exogenous triglycerides was markedly reduced and this change seems to account for the hypertriglyceridemia associated with thyroid hypofunction. The plasma PHLA was also clearly decreased in the hypothyroid state.Plasma FFA and glycerol levels were increased in hyperthyroidism and plasma FFA was slightly decreased in hypothyroid patients, but these variables were not significantly correlated with any parameter of triglyceride metabolism.Endogenous triglyceride turnover rate was significantly correlated with serum protein-bound iodine (PBI) and T3 uptake in thyrotoxicosis but not in hypothyroidism. Removal of exogenous fat was not related to postheparin plasma lipolytic activity but the fractional endogenous triglyceride transport showed a highly significant relationship to this lipase activity in a mixed group of hyper- and hypothyroid patients.The results suggest that thyroid hormones control both production and removal of plasma triglycerides. Different mechanisms for these interactions are considered.     

The triglyceride connection in atherosclerosis.

OBJECTIVE: To examine the proposed mechanism of triglyceride-induced atherogenesis, to address the controversy surrounding serum triglycerides as a coronary heart disease (CHD) risk factor, and to recommend an appropriate therapeutic approach to hypertriglyceridemia. DATA SOURCES: Studies, review articles, and editorials published since 1976. A MEDLINE search of English-language literature was conducted using the terms triglyceride and hypertriglyceridemia. STUDY SELECTION: Studies, review articles, and editorials were selected for detailed review if they addressed the pathogenesis of triglyceride-induced atherosclerosis, the controversy associated with elevated serum triglyceride as a CHD risk factor, and hypertriglyceridemia treatment options. DATA EXTRACTION: Data were reviewed that described the atherogenicity of chylomicron and very low-density lipoprotein (VLDL) remnants, the inverse relationship that exists between high-density lipoprotein (HDL) and serum triglyceride, the hypertriglyceridemia treatment controversy, and the treatment options of diet, exercise, weight control, alcohol restriction, and medication. DATA SYNTHESIS: Hypertriglyceridemia is a well-known risk factor for pancreatitis. However, its role in atherogenesis is less well defined. Several proposed connections appear to exist between hypertriglyceridemia and atherosclerosis, including the inverse correlation between triglycerides and HDL, the presumed atherogenicity of triglyceride-rich lipoprotein remnant particles, the potential resultant increase in the serum concentration and atherogenicity of low-density lipoprotein (LDL), and the proposed interaction between serum triglyceride and the fibrinolytic/coagulation system. Clinical trials addressing this issue offer mixed results that are subject to interpretation. Diet, exercise, weight control, alcohol restriction, and certain lipid-lowering medications are effective at reducing serum triglyceride. CONCLUSIONS: Hypertriglyceridemia is a theoretical risk factor for CHD because of the increased production of atherogenic chylomicron and VLDL remnants, the inverse relationship present between serum triglyceride and HDL, the possible resultant increase in LDL attributable to remnant-reduced hepatic LDL-receptors as well as the formation of more dense and, therefore, more atherogenic LDL, and to the interaction between serum triglyceride and the fibrinolytic/coagulation system. However, most clinical trials that have found hypertriglyceridemia to be a risk factor for CHD do not include other CHD risk factors in their analyses. Therapeutic intervention to lower serum triglyceride with diet, exercise, and/or drugs is definitely recommended in the treatment and/or prevention of pancreatitis; however, the role of triglyceride-lowering to reduce CHD risk remains controversial.