Background. The published reports of the effectiveness of simvastatin in treatment of hypercholesterolemia were mostly conducted in western populations, and only few studies in Asian or domestic populations have ever been reported. By regulations from Bureau of National Health Insurance, the effective dosage of lipid lowering agents should be started from lower dose, such as 20 mg of simvastatin per day. Whether this dosage of simvastatin is effective for treatment of patients with hypercholesterolemia and the efficacy and safety of such dosage are the objects of this study. Materials and Methods. After the approval of IRB in a medical center located at north Taiwan, a randomized 12-week study was conducted to evaluate the efficacy and safety of 20mg/day simvastatin treatment on hypercholesterolemia. By randomization 65 patients, followed up at cardiovascular outpatient department under the diagnosis of primary hypercholesterolemia, were enrolled into a 4-week washout period, and finally 49 intent-to-treat patients entered a 12-week treatment with 20mg simvastatin per day, given through oral routine in the evening. Demographic and laboratory data were obtained before and after treatment. The primary efficacy measure was the changes from baseline in lipid parameters. Tolerability was assessed in terms of the overall incidence of adverse experiences and the most commonly reported adverse experiences. Results. The per-protocol analyses included 39 hypercholesterolemic patients whom completed 12 weeks of therapy. Total cholesterol and LDL cholesterol at the end of the study period showed significant reductions by 22.5¢H (p<0.001) and 29.8¢H(p<0.001), respectively. Triglyceride also showed a significant reduction by 31.8% (p=0.006), whereas total alkaline phosphatase and calcium showed a weak and insignificant change over the study period. The female group had significantly greater reduction in triglyceride than that in the male group, and the non-smoking group also had significantly greater reduction in triglyceride than that in smoking group after 12-week treatment. There were 17 studied cases (34.7%) had minor transient but clinical insignificant increases in serum aspartate aminotransferase and alanine aminotransferase, and 7 cases (14.3%) experienced symptom of painful muscle, of whom 3 cases (6.1%) dropped out this study. Conclusion. Our results, although obtained from a small scale of hypercholesterolemic patients, suggest a probable positive efficacy and good tolerability with only few minor side effects of simvastatin on blood lipids.

Heart-type fatty acid binding protein (H-FABP) is a major fatty acid binding factor in skeletal muscles. Genetic lack of H-FABP severely impairs the esterification and oxidation of exogenous fatty acids in soleus muscles isolated from chow-fed mice (CHOW-solei) and high fat diet-fed mice (HFD-solei), and prevents the HFD-induced accumulation of muscle triglycerides. Here, we examined the impact of H-FABP deficiency on the relationship between fatty acid utilization and glucose oxidation. Glucose oxidation was measured in isolated soleus muscles in the presence or absence of 1 mM palmitate (simple protocol) or in the absence of fatty acid after preincubation with 1 mM palmitate (complex protocol). With the simple protocol, the mutation slightly reduced glucose oxidation in CHOW-muscles, but markedly increased it in HFDmuscles; unexpectedly, this pattern was not altered by the addition of palmitate, which reduced glucose oxidation in both CHOW- and HFD-solei irrespective of the mutation. In the complex protocol, the mutation first inhibited the synthesis and accumulation of triglycerides and then their mobilization; with this protocol, the mutation increased glucose oxidation in both CHOW- and HFD-solei. We conclude: (i) H-FABP mediates a non-acute inhibition of muscle glucose oxidation by fatty acids, likely by enabling both the accumulation and mobilidoes not mediate the acute inhibitory effect of extracellular fatty acids on muscle glucose oxidation; (iii) H-FABP affects muscle glucose oxidation in opposing ways, with inhibition prevailing at high muscle triglyceride contents.zation of a critical mass of muscle triglycerides; (ii) H-FABP

Regensburg, Univ., Diss., 2005.

An assay based on Nile red fluorescence was developed for quantitative analysis of triglycerides, a common cellular component with important biological functions and is routinely analyzed for diagnosis of metabolic disorders and as an important feedstock of food industry and biodiesel production. Based on studies on the Nile red fluorescence of pure, binary, and ternary systems of triglycerides, ethanol, and water, 20% ethanol aqueous solution was determined to be the most suitable solvent for lipid fluorescence measurement. Excellent linearity was established for lipid samples in the range of 0.1- 0.5 mg/ml with several different lipid standards and vegetable oils. Results also suggest that the fluorescence of triglycerides was not sensitive to the fatty acid composition of lipids. This finding is important since it implies that the assay could potentially be used for the measurement of triglyceride content of different oil crops without causing significant variations. The results of this method were then verified by comparing with the results of the conventional gravimetric methods. The results of the fluorescence assay were consistently lower than that of the gravimetric method by approximately 10%. This phenomenon was tentatively attributed to the fact that the gravimetric method measures the total amount of lipophilic materials in samples while the fluorescence assay is selective to glycerides. Attempts were also made to apply this assay to estimate the lipid content of green alga Neochloris oleoabundans. However, the results were less than ideal due to the existence of interfering components in the extract of microalga samples that could significantly repress the fluorescence of lipids.

Digestion and absorption of bioactive free fatty acids have been studied using the nematode Caernohabditis elegans (C. elegans). However, fatty acids mostly occur in foods in the form of triglycerides, which are highly hydrophobic molecules with low water-solubility, thereby making it difficult to study the fate of ingested fatty acids in C. elegans. The purpose of this research was to develop a method to deliver hydrophobic bioactives, including triglycerides, into C. elegans. Nanoemulsions containing triglyceride nanoparticles were prepared by sonication, and nanoparticle ingestion was confirmed by optical and confocal microscopy, and quantified by spectrometry. Changes in fatty acid composition were measured to confirm the absorption of triglycerides delivered as nanoparticles. Nanoparticles with a wide range of particle diameters (40 to 500 nm) were ingested by C. elegans. The ingested triglyceride amount was dependent on the size and concentration of the nanoparticles, but the fatty acid composition of C. elegans was not significantly changed by dietary triglycerides. Nanoemulsion based-delivery systems enable C. elegans to be used for evaluation of hydrophobic bioactives and may provide a useful tool for testing their biological activities.

No description available.

The interaction between low-density lipoprotein (LDL) and glycosaminoglycans is a key factor in atherosclerosis. The present study examines the characteristics of LDL and its binding properties with the main glycosaminoglycan of the vascular wall, chondroitin 6- sulphate (C6S). The compositional characteristics that were studied for each LDL sample were phase transition temperature, phospholipid content, free cholesterol content, cholesteryl ester content, triglyceride content, and size. Correlations of these characteristics with LDL-C6S binding were analyzed using a turbidity assay. Our results showed that there is no correlation between LDL-C6S binding and phase transition temperature, triglyceride content, or size. Strong correlations were present for LDL-C6S binding and phospholipid content (P < 0.0001, r2 = 0.4591), free cholesterol content (P < 0.01, r2 = 0.2495), and cholesteryl ester content (P < 0.005, r2 = 0.2952). When values for surface (phospholipids and free cholesterol) and core (cholesteryl esters and triglycerides) lipids were determined a positive correlation was also present with LDL-C6S binding (P < 0.0005, r2 = 0.4172; P < 0.0005, r2 = 0.4282; respectively). These results indicate that large, lipid-rich LDL particles have a higher capacity to bind C6S than smaller, lipid poor LDL. Possible implications for the atherogenicity of LDL are discussed.

Lipid homeostasis is an essential factor for proper function both at the level of a cell and of an organism. Dysregulation of this process is responsible for some of the major health concerns of our societies such as obesity and atherosclerosis. Considering the wide variety of lipids and the high dynamic of the system, it is clear that regulation is required to keep the appropriate balance between the different lipids. Although a few regulation pathways are already characterized, some others still wait to be discovered. In order to unravel new players involved in lipid regulation, a screening procedure was developed combining RNA interference in Hela cells and thin layer chromatography. Thereby, it is possible to monitor modifications of lipid composition resulting from siRNA knock-down. Furthermore, the potential of mass spectrometry as a lipid analysis tool in large-scale studies was evaluated. This method was then applied to an essential family of regulatory proteins, the kinases. Lipid composition of 600 kinases knock-downs was analyzed. Mostly, variations in triglyceride and cholesterol levels were observed, suggesting that these lipids are more subject to variation in the cells. Unfortunately, it appears that the screen suffered from a high-rate of off-targets effects, implying that most of the phenotypes observed can’t reliably be linked to the corresponding kinase knock-downs. However, several interesting conclusions can still be derived from this screen. First, it was observed that several siRNA induce a decrease in cholesterol, which is coupled to accumulation of a new lipid. Several lines of evidence suggest that this new lipid is in fact a methylated sterol precursor such as lanosterol or demethyllanosterol. Previously, HMG-CoA reductase was considered as the rate-limiting enzyme of cholesterol biosynthesis and the major regulated step of this process. These data show that another major regulation step occurs more downstream in the pathway at the level of methylated cholesterol precursors. Furthermore, MAPK9 was identified as a new regulator of triglyceride homeostasis at the cellular level. Upon MAPK9 knock-down, an increase in triglyceride content was observed both by thin layer chromatography and mass spectrometry. Accordingly, these cells present an increase in lipid droplets, the cellular organelles responsible for triglyceride storage. Sty1 was also identified as the functional homolog of MAPK9 in S. pombe for this process, as similar increase in triglyceride and lipid droplets is observed in a deletion strain for this gene. Although more detailed studies will be necessary to unravel the molecular mechanism of this process, these data suggest the evolutionary conserved implication of the MAP kinase pathway in the regulation of lipid storage both in humans and in yeasts.

Thesis (doctoral)--Rheinisch-Westfälische Technische Hochschule Aachen, 1994.

Stuttgart, Univ., Diss., 2005.