Variation in plasma lipids with age and sex in a hypertriglyceridemic rat

A substrain of the Long Evans rat having the characteristics of a common human lipid disorder, hypertriglyceridemia, is described. These rats were found to be hypercholesterolemic, hyperphospholipidemic and normotriglyceridemic during the first month of life when feeding predominantly on the higher lipid, lower carbohydrate content of their mothers' milk. After weaning (22 days of age), when a typical higher carbohydrate and lower fat containing commercial laboratory feed was substituted for mother's milk, plasma cholesterol and phospholipid levels declined and triglyceride levels significantly increased. Electrophoretic analysis of lipoproteins revealed the presence of a pre-β fraction and the absence of chylomicra, indicating that this rat is a type IV according to the Fredrickson classification system. Glucose tolerance curves remained elevated for a longer period of time and returned to normal more slowly in 1 year old compared to 2 month old males, indicating progressive alterations in glucose metabolism common in a Fredrickson type IV. After weaning, plasma phospholipid, cholesterol and triglyceride levels were significantly higher and body weight significantly lower in the female than in the male. Studies on hematocrit and hemoglobin variations with respect to age in both sexes indicated that the observed plasma lipid changes could not be attributed to hemoconcentration.     

Association of ceramides in human plasma with risk factors of atherosclerosis

Atherosclerosis is a multifactorial disorder. Recent studies indicate that the plasma level of sphingomyelin, which yields ceramide, correlates with the risk of coronary heart disease. Therefore, ceramide, a well-known lipid causing apoptosis in various cell types, may contribute to atherogenesis. We examined the relationship between ceramide concentration and risk factors of atherosclerosis in normal human plasma using electrospray tandem mass spectrometry (LC-MS/MS). Major ceramides in human plasma were C24∶0 and C24∶1. The ceramide concentration showed a significant positive correlation with total cholesterol (TC) and triglycerides (TG). In addition, plasma ceramide level increased drastically at a high level of LDL cholesterol (more than 170 mg/dL). Our previous studies demonstrated that the sum of fragmented and conjugated apolipoprotein B-100 proteins (B-ox), which were products of a radical reaction of LDL as well as plasma, was a reliable index of atherosclerosis. B-ox showed a significant positive correlation with the plasma ceramide level. Based on these results, we propose that the ceramide level in human plasma is a risk factor at the early stages of atherosclerosis.     

Distribution of antithrombin III and glucosylceramide in human plasma lipoproteins and lipoprotein deficient plasma

We have investigated the distribution of antithrombin-III and glucosylceramide (Glc-Cer) in human plasma, plasma lipoproteins and lipoprotein-deficient plasma. Antithrom bin III activity was measured employing immunochemical and biological assays. Glc-Cer was quantified by gas liquid chromatography (GLC). Whole plasma contained 145 μg antithrombin III/ml plasma, all of which was associated with the lipoprotein-deficient plasma (d>1.25 g/ml). Whereas, most if not all the plasma GlcCer was associated with plasma low density lipoproteins (LDL) (d-1.022–1.055 g/ml) and high density lipoproteins (HDL) (d-1.063–1.25). GlcCer was not found in the lipoprotein-deficient plasma. We conclude that GlcCer on lipoproteins does not contribute to antithrombin III activity. Moreover, the absence of GlcCer in lipoprotein-deficient plasma does not impair antithrombin-III activity.     

Correlation between post-heparin lipase and phospholipase activities in human plasma

The hypothesis that a single lipolytic enzyme in post-heparin plasma effects the hydrolysis of both triglyceride and phospholipid was tested. After intravenous heparin, activity in plasma with the two substrate classes appeared and disappeared in parallel. The activities were not separable by the fractionation methods of zone electrophoresis, gel filtration, anion-exchange, ultracentrifugation, or by combinations of these techniques. The degree of purification of the two activities with the use ofn-butanol was similar. Lipolytic activity appeared to be associated with a large high density molecular aggregate. However, the concept of a single post-heparin enzyme does not explain all the observations since the ratio of activity with triglyceride substrate to activity with phospholipid substrate decreased markedly in some subjects after increased amounts of intravenous heparin. Presented in part at the AOCS Meeting, Washington, D.C., April 1968.     

冻干人血浆补体的制备及其稳定性

目的制备冻干人血浆补体,并观察其在4种不同保存温度条件下的稳定性。方法制备3批冻干人血浆补体,将每批样品分别保存在-70、4、25和37℃条件下,采用补体50%溶血试验测定于-70和4℃条件下保存第1、15、30、60、90、120、180、270、365天以及于25和37℃条件下保存第1、5、10、15、20、30、40、50、60、70、80、90、100、110、120天的CH_(50);细胞增殖-毒性检测法测定补体对抗CD_(20)抗体CDC活性检测的影响。结果-70和4℃保存的3批冻干人血浆补体,1年内CH_(50)平均下降了19.5%和36.3%,25和37℃保存的3批冻干人血浆补体,3个月CH_(50)平均下降了53.4%和60.7%。与上市补体和CH_(50)为30 U/ml的冻干人血浆补体相比,CH_(50)为15 U/ml的冻干人血浆补体对抗CD_(20)抗体CDC活性检测结果无影响。结论在-70和4℃条件下保存的冻干人血浆补体的CH_(50)相对较稳定,但随着保存温度的升高,CH_(50)下降有加速的趋势。CH_(50)大于15 U/ml的冻干人血浆补体可用于治疗性抗体CDC活性检测。     

Genetic variability of human plasma and erythrocyte lipids

Genetic variation of fasting plasma lipids, lipoproteins and erythrocyte membrane lipids was studied in 67 sets of like-sexed twins and 3 sets of triplets. All of the plasma lipids were more variable in dizygotic twins than monozygotic twins with the exception of phosphatidyl ethanolamine, but only cholesteryl esters, lecithin, phosphatidyl inositol and β-lipoprotein showed significant genetic variation. In contrast, no significant genetic variability was found in any of the erythrocyte membrane lipids and erythrocyte phosphatidyl ethanolamine had significantly greater variation in monozygotic twins. Two sets of twins had an extra lipoprotein band (slow α1); in one family the variant appeared to be segregating as a dominant trait. Presented in part at the ISF-AOCS World Congress, Chicago, September 1970.     

Antioxidative activity of 3,4-dihydroxyphenylacetic acid and caffeic acid in rat plasma

The purpose of the present paper is to study and compare in vitro the inhibitory effect of 3,4-dihydroxyphenylacetic acid (DOPAC) and caffeic acid (CA) on lipid peroxidation in rat plasma. Rat plasma was oxidized at 37°C by the radical initiators 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) or 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (MeO-AMVN). The consumption of endogenous α-tocopherol (α-TOH) and the accumulation of conjugated diene hydroperoxides were measured by high-performance liquid chromatography and by ultraviolet spectroscopy, respectively. α-TOH was consumed at the same rate in the presence of 20 mM AAPH or 2 mM MeO-AMVN. DOPAC and CA suppressed the α-TOH consumption in a dose-dependent manner. A concentration of 50 μM of both phenolic acids was sufficient to induce a lag phase and to delay the rate of α-TOH consumption. The effect was more pronounced in rat plasma oxidation by AAPH than by MeO-AMVN. CA spared vitamin E more effectively than DOPAC in both oxidations. DOPAC and CA suppressed the formation of conjugated diene hydroperoxides. DOPAC and CA at concentration 50 μM suppressed α-TOH consumption during oxidation of soybean phosphatidylcholine (2.8 mM) multilamellar vesicles containing 15 μM α-TOH, in which the lipophilic initiator 2,2′-azobis (2,4-dimethylvaleronitrile) (6 mM) was incorporated. In conclusion, we demonstrated that DOPAC and CA in micromolar concentrations have antioxidant activity in rat plasma, a medium very close to the conditions in vivo, suggesting that supplementation with the phenolic acids will provide significant antioxidant protection.     

Role of PLLA plasma surface modification in the interaction with human marrow stromal cells

The effects of oxygen‐based radio frequency plasma enhanced chemical vapor deposition (rf PECVD) on the surface of poly(L ‐lactide) (PLLA) polymers and the influence thereof on protein adsorption and on bone–cell behavior have been studied. Thin films and porous scaffolds based on PLLA polymer were developed, and the role of surface modifications were investigated extensively. PECVD surface treatments were used to alter surface functionality and modulate protein adsorption on the PLLA polymer matrix. In particular, Bovine Serum Albumine fluorescein isothiocyanate (fitc‐BSA) conjugate adsorption on patterned surfaces of treated PLLA was analyzed by fluorescence microscopy. Human marrow stromal cells (MSCs) were cultured on scaffolds and cell adhesion and morphology were assessed using fluorescence microscopy. The results indicated that the PLLA surface became hydrophilic and its roughness increased with the treatment time and it had a dominant influence on the adsorption process of the protein. The outcome of the plasma treatment of various PLLA surfaces has been shown to be the up‐regulator of the cell‐adhesive proteins expression and consequently the improvement of cell adhesion and growth. Oxygen‐treated PLLA promoted higher adhesion and proliferation of the MSCs in comparison to the untreated samples. It can be concluded that following plasma treatment, PLLA samples show enhanced affinity for osteoprogenitor cells. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Differential utilization of eicosapentaenoic acid and docosahexaenoic acid in human plasma

It has recently been shown that the ω3 fatty acid status in humans can be predicted by the concentration of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in plasma phospholipids [Bjerve, K.S., Brubakk, A.M., Fougner, K.J., Johnsen, H., Midjthell, K., and Vik, T. (1993)Am. J. Clin. Nutr., in press]. In countries with low intake of ω3 fatty acids, the level of EPA in plasma phospholipids is often only about one-fifth the concentration of DHA. The purpose of this study was to investigate whether this difference in the concentration of these two fatty acids was due to a selective loss of EPA relative to DHA or to a lower dietary intake of EPA. Seven female volunteers ingested four grams of MaxEPA daily for 2 wk and in the following 4 wk they ate a diet almost completely devoid of the long-chain ω3 fatty acids. The concentrations of the ω3 fatty acids in the plasma cholesteryl esters, triglycerides and phospholipids and the high density lipoprotein phospholipids were examined at weekly intervals throughout the study. There was a more rapid rise in the concentration of EPA than in DHA levels in the supplementation period in all lipid fractions, but there was a disproportionate rise in DHA relative to EPA in the plasma lipids compared with the ratio in the supplement. In the depletion phase there was a rapid disappearance of EPA from all fractions, such that pre-trial levels were reached by one week post-supplementation. The disappearance of DHA was slower, particularly for the plasma phospholipids: at 4 wk post-supplementation, the DHA concentration in this fraction was still 40% above the pre-trial value. It is suggested that the low plasma EPA values relative to DHA are the result of increased β-oxidation of EPA and/or low dietary intake, rather than a rapid conversion of EPA to DHA. One practical result of this experiment is that, compared with DHA, the maintenance of increased EPA levels in plasma (and therefore tissues) would require constant inputs of EPA due to its more rapid loss from the plasma.     

Analysis of ubiquinone and tocopherol levels in normal and hyperlipidemic human plasma

The type and amount of lipophilic antioxidants in plasma of hyperlipidemic patients are of great importance since they play a central role in preventing deleterious oxidation of blood lipids and proteins. Isolation and quantitation of lipophilic antioxidants from hyperlipidemic plasma samples meet great obstacles because of increased levels of various intermediary lipid products. This study was designed to develop a rapid and efficient extraction and separation procedure for simultaneous analysis of ubiquinone-9 and-10 as well as α-, δ-, and γ-tocopherol isomers. The levels of ubiquinone-10, α- and γ-tocopherol were analyzed in human plasma samples using high-performance liquid chromatography. Lipid extraction was performed by petroleum ether/methanol/water. After phase separation, ubiquinone was reduced to ubiquinol by sodium borohydride and the lipids were separated on a C18 column. A binary gradient with solvents containing lithium perchlorate was used, and an electrochemical detector was employed for quantitation. This procedure was also efficient for the analysis of antioxidant lipids in samples containing a large number of accumulated and interfering lipid intermediates. Thus, the procedure described here is useful for efficient and rapid quantitation of ubiquinones and tocopherols in human plasma samples, especially those originating from hyperlipidemic patients.     

Metabolic fate of sphingomyelin of high-density lipoprotein in rat plasma

The metabolic fate of high density lipoprotein (HDL) sphingomyelin in plasma was studied in rats over a 24-hr period after injection of HDL containing sphingomyelin which was¹⁴C-labeled in the stearic (18∶0) or lignoceric acid (24∶0) moiety and³H-labeled in the choline methyl groups. Decay of label in plasma followed three phases. The first two phases were similar for both isotopes and both types of sphingomyelin (t_1/2≃10 and 110 min). However, during the third phase (from 10 hr after injection),³H label disappeared more slowly than¹⁴C label from 18∶0 sphingomyelin, whereas the³H/¹⁴C ratio remained relatively constant when 24∶0 sphingomyelin was used. Intact, doubly-labeled 18∶0 sphingomyelin disappeared from HDL rapidly (t_1/2=38 min) by tissue uptake and by transfer to very low density lipoprotein (VLDL). VLDL contained up to 12% of the sphingomyelin 1 hr after injection. This is the first demonstration of a transferin vivo of sphingomyelin from HDL to VLDL. A similarly rapid transfer was also observedin vitro. Some nontritated, [¹⁴C]18∶0 or [¹⁴C]24∶0 sphingomyelin was redistributed more slowly into HDL. Doubly-labeled phosphatidylcholine appeared in VLDL and HDL within 1 hr after injection and reached 1.8 and 2.1% of the injected¹⁴C and³H in VLDL at 1 hr, and 4.8 and 6.9% in HDL at 3 hr, respectively.     

特定蛋白检测仪检测血浆IgG含量方法的验证及其应用

目的对特定蛋白检测仪BN-P检测血浆IgG含量的散射比浊法(nephelometry)进行验证,并用于层析法制备IgG的工艺过程监控。方法使用BN-P和IgG相关试剂对检测IgG含量的散射比浊法进行线性和范围、准确度、精密度、专属性、耐用性验证,并进行样品添加试验,将用该方法检测5批IgG成品的结果与凯氏定氮法比较,同时检测层析法制备的3批IgG工艺过程样品中IgG含量。结果用该方法检测蛋白SL标准品中IgG的线性范围为0.107~0.003 34 g/L;高、中、低浓度的SL/H(高水平)蛋白质控品的批内准确度为87.60%~91.05%,批间准确度为88.5%~90.5%;批内精密度CV值为1.85%~3.65%,批间精密度CV值为2.46%~3.16%;检测方法不受血浆白蛋白的干扰,专属性良好;样品经反复冻融5次以内检测,耐受性良好,5次以上耐受性较差;样品添加试验的回收率在90.2%~93.1%之间。该方法检测5批IgG成品中IgG含量,与凯氏定氮法相比差异无统计学意义(P0.05);该方法检测3批IgG工艺过程中间品重复性较好,步骤回收率一致,工艺稳定。结论特定蛋白检测仪BN-P检测血浆IgG含量的散射比浊法准确可靠,可用于IgG制备工艺的过程监控。     

Effect of age on plasma bile acids and lipid components in the rat

With increasing age, total plasma bile acid contents increased in rats over a period of 11 months, and also total plasma cholesterol and carcass fat contents increased in the same manner. Plasma showing high bile acid levels at 11 months was found by means of high performance liquid chromatography to contain cholic acid as one of the major components, chenodeoxycholic acid and trace deoxycholic acid. These results suggest that there are close relationships between the plasma bile acids and age-dependent changes of lipid components in the rat.     

Affinity of amine-functionalized plasma polymers with ionic solutions similar to those in the human body

This work presents a study on the synthesis and on the interaction of allylamine, pyrrole and ethylenglycol polymerized by plasma with solutions of ionic composition similar to those in the nervous system. These polymers are attractive substrates to interact with the ionic pulses of the spinal cord due to their electrical and biocompatible characteristics. The ionic solutions were prepared with aqueous combinations of NaCl, MgSO₄, KH₂PO₄, KCl, CaCl₂, and NHCO₃. The polymers were prepared as thin films on glass substrates. The results indicated that some of the most important physical characteristics in the hydrophilicity of the polymers, roughness, porosity and functional groups, can be controlled with the energy of polymerization. The interaction between polymers and solutions was studied measuring the contact angle at the solid–liquid interface and the electrical conductivity of the polymers wet with these solutions. The contact angles were between 8° and 38°, and the electrical conductivity was in the 10^?8 to 10^?9 S/cm interval. The general tendencies indicate that the amine-functionalized polymers of this work are good materials to interact with the spinal cord system.     

Identification of a deoxyguanosine-malondialdehyde adduct in rat and human urine

In an ongoing study, rat and human urine have been examined for the presence of malondialdehyde (MDA) derivatives as indicators of the nature of lipid peroxidative damage caused by this compoundin vivo. MDA in urine was found to be present mainly in the form of two lysine adducts, one acetylated and the other unacetylated, reflectingin vivo reactions with tissue proteins. Two minor metabolites were identified as adducts with the phospholipid bases serine and ethanolamine and a third one as an adduct with the nucleic acid base guanine. The identification of an MDA adduct with deoxyguanosine (dG-MDA) among the products of hydrolysis of rat liver DNA suggested the possible occurrence of this compound in urine. In the present study dG-MDA was identified in rat and in human urine, and a high-performance liquid chromatographic method utilizing fluorescence detection was developed for its estimation. The method is sensitive to 1 pmol of dG-MDA and requires a minimum of 1 mL of rat urine or 5 mL of human urine. Its rate of excretion by five-week-old rats (28.54±2.28 nmol/kg/24 h) (mean±SEM) was higher than that for nine-week-old rats (6.29±1.02) and much higher than that for adult humans (0.40±0.05). The results indicate that, as reported for 8-hydroxy-deoxyguanosine, dG-MDA excretion is related to metabolic rate. Excretion of dG-MDA by the rat, like the excretion of total MDA, declines during growth on a body weight basis at a rate similar to the decrease in resting energy metabolism. In contrast to other MDA derivatives excreted in rat urine, vitamin E deficiency had no effect on the excretion of dG-MDA. Together with evidence that the dG-MDA content of rat liver DNA likewise is unaffected by vitamin E depletion or by administration of catalysts ofin vivo lipid peroxidation, these findings indicate that DNA is protected from lipid peroxidative damage, possibly through conservation of the vitamin E associated with the lipids of the nuclear membrane.     

Lipophilic aldehydes and related carbonyl compounds in rat and human urine

Rat and human urine samples were analyzed for lipophilic aldehydes and other carbonyl products of lipid peroxidation. The following compounds were identified as their 2,4-dinitrophenyl hydrazones by cochromatography with pure standards using three solvent systems: butanal, butan-2-one, pentan-2-one, hex-2-enal, hexanal, hepta-2,4-dienal, hept-2-enal, octanal, non-2-enal, deca-2,4-dienal, 4-hydroxyhex-2-enal, and 4-hydroxynon-2-enal. In general, fasted rats excreted less of these compounds than fed rats, indicating they were partially of dietary origin or that the endogenous compounds were excreted in a form not susceptible to hydrazone formation. The compounds excreted in human urine were similar to those excreted in rat urine but were present in lower concentrations. Identification of the conjugated forms fo the lipophilic aldehydes and related carbonyl compounds excreted in urine may be a source of information about their reactions in vivo.     

Distribution of deuterium-labeledcis-andtrans-12-octadecenoic acids in human plasma and lipoprotein lipids

Triglycerides containingcis- andtrans-12-octadecenoic acid (12c-18∶1 and 12t-18∶1) andcis-9-octadecenoic acid (9c-18∶1) labeled with deuterium were fed to 2 young adult male subjects. These fatty isomers each contained a different number of deuterium labels, which allowed mass spectrometric analysis to distinguish among them after they were fed as a mixture. This approach results in a direct comparison of the absorption and distribution of these 3 monoenoic acids into blood plasma and lipoprotein lipids. Plasma lipid data indicated that all phospholipid fractions selectively incorporate 12c-18∶1 and 12t-18∶1 in preference to 9c-18∶1. Discrimination against 12c-18∶1 and 12t-18∶1 compared to 9c-18∶1 was found in the plasma neutral lipids, with a strong discrimination against 12t-18∶1 incorporation into the cholesteryl ester fraction. Considerable reduction in the percentage of linoleic and arachidonic acid was observed when 12–18∶1 isomers were incorporated in plasma triglyceride, phosphatidylcholine and sphingomyelin samples. Chylomicron lipid analyses indicated that all isomers were well absorbed. Variation was observed in the relative distribution of 12c-18∶1, 12t-18∶1 and 9c-18∶1 between the very low density, low density and high density lipoprotein lipid classes. No desaturation of 12c-18∶1 to linoleic acid was detected.     

Ocratoxin A in human plasma and coffee from Costa Rica by ELISA

Costa Rica is not an exception in the prevalence of ochratoxin A in human plasma, in this research the presence of the micotoxin was found in 95% of the 149 samples studied. The presence of ocratoxina A also was studied in 110 samples of toasted and grounded coffee from the most important 12 coffee factories of the country and from 7 supermarkets. With the exception of one negative sample the rest of them have concentrations of micotoxin below 4000 ng/kg. An association between the coffee consumption and the presence of ochratoxin A in plasma was attempted to be found as well as in the consumption of beer, but there were any statistically significant difference in the average level of mycotoxin between the coffee consumers and non coffee consumers neither between beer consumers and no beer consumers.