An improved method for extracting the lipids from tissues consists of the use of hexane:isopropanol, followed by a wash of the extract with aqueous sodium sulfate to remove nonlipid contaminants. This method has a number of advantages over the common usage of chlorofomnmethanol. The solvents are somewhat less toxic, interference in processing by proteolipid protein contamination is avoided, the two phases separate rapidly during the washing step, the solvent density is low enough to permit centrifugation of the homogenate as an alternative to filtration, the solvents are cheaper, and the washed extract can be applied to a chromatographic column with continuous monitoring of the elution in the far ultraviolet region. The new extraction method is inefficient for the extraction of gangliosides. Biochemists wishing to extract lipids from tissues have in the past paid rather little attention to questions of danger to their health or to the health of people living downstream from their sewage treatment plants. Recent findings from public health studies and animal experiments have implicated a wide variety of organic solvents in the production of tumors, through exposure in the work place or in drinking water. It therefore seems appropriate to review lipid extraction techniques as a potential health hazard. While many solvents have been recommended [for reviews see Refs. (l-3)], the most popular is the chloroform:methanol (CM)' system of Folch et al. (4) and its various modifications. Chloroform can produce tumors in animals (5) and methanol is well known for its damage to the visual system. A choice of solvents for lipid extraction should be made on the basis of several additional factors: volatility (for ready removal later), freedom from toxic or reactive impurities (to avoid reaction with the lipids), ability to form a two-phase system with water (to remove nonlipids), extraction power for undesired components (proteolipid proteins, small molecules), price, range of extraction power for the different lipid classes, and ultraviolet transparency for subsequent column chromatography and monitor-1 Abbreviations used: HIP, hexane:isopropanol, usually in the ratio 3:2. CM, chloroform: methanol, usually in the ratio 2: 1.

The triglyceride-lowering effect of bezafibrate in humans has been attributed to peroxisome proliferator-activated receptor (PPAR) ␣ activation based on results from rodent studies. However, the bezafibrate dosages used in conventional rodent experiments are typically higher than those in clinical use (Ն50 versus Յ10 mg/kg/day), and thus it remains unclear whether such data can be translated to humans. Furthermore, because bezafibrate is a pan-PPAR activator, the actual contribution of PPAR␣ to its triglyceride-lowering properties remains undetermined. To address these issues, bezafibrate at clinically relevant doses (10 mg/kg/day; low) was administered to wild-type and Ppara-null mice, and its effects were compared with those from conventionally used doses (100 mg/kg/day; high). Pharmacokinetic analyses showed that maximum plasma concentration and area under the concentration-time curve in bezafibrate-treated mice were similar to those in humans at low doses, but not at high doses. Low-dose bezafibrate decreased serum/liver triglycerides in a PPAR␣-independent manner by attenuation of hepatic lipogenesis and triglyceride secretion. It is noteworthy that instead of PPAR activation, down-regulation of sterol regulatory element-binding protein (SREBP)-1c was observed in mice undergoing low-dose treatment. High-dose bezafibrate decreased serum/liver triglycerides by enhancement of hepatic fatty acid uptake and ␤-oxidation via PPAR␣ activation, as expected. In conclusion, clinically relevant doses of bezafibrate exert a triglyceride-lowering effect by suppression of the SREBP-1c-regulated pathway in mice and not by PPAR␣ activation. Our results may provide novel information about the pharmacological mechanism of bezafibrate action and new insights into the treatment of disorders involving SREBP-1c.Bezafibrate and other fibrate drugs are clinically used as hypolipidemic agents to preferentially lower serum triglyceride (TG) levels. Several large-scale clinical trials have demonstrated a relationship between the TG-lowering effect of fibrates and a reduction in the risk of cardiovascular events in patients with dyslipidemia, type 2 diabetes mellitus, and metabolic syndrome (BIP Study Group, 2000;Keech et al., 2005;Tenenbaum et al., 2005). The mechanisms accounting for the hypolipidemic effect of fibrates in humans are explained mainly as an increase in the lipolysis of TG-rich lipoproteins, such as very-low-density lipoprotein (VLDL),

Sulfatides, normal components of serum lipoproteins, may play an important role in cardiovascular disease due to their various modulatory functions in haemostasis. The incidence of cardiovascular disease in patients with end-stage renal failure undergoing maintenance hemodialysis has been reported to be approximately 10 to 30 times higher than that in the general population. To elucidate the possible roles of serum sulfatides in this high incidence, we measured the level of sulfatides in 59 such patients, by converting them to lysosulfatides according to a recently developed quantitative, qualitative, high-throughput technique using matrix-assisted laser desorption ionization-time of flight mass spectrometry. The mean level of sulfatides in patients 3.58 +/- 1.18 nmol/ml was significantly lower than that in age-matched normal subjects (8.21 +/- 1.50 nmol/ml; P < 0.001). Patients receiving maintenance hemodialysis over a longer period had lower levels of sulfatides. When the mean levels of sulfatides were compared between patients with cardiovascular disease (N = 22) and those without the disease (N = 37), the level in the former group 2.85 +/- 0.67 nmol/ml was found to be significantly lower than that in the latter group 4.01 +/- 1.22 nmol/ml (P < 0.001). These findings reveal a close correlation between low levels of serum sulfatides and a high risk of cardiovascular disease in these patients. Determination of the level of serum sulfatides can contribute to predictions of the incidence of cardiovascular disease in patients with end-stage renal failure undergoing maintenance hemodialysis.

Background:The vitamin D receptor (VDR) is involved in a variety of biological processes, such as bone metabolism and modulation of the immune response. Recent findings suggest that the pathway involving bone mineral density-mediated effects is important for the development of periodontitis, but their effects of combined VDR gene polymorphisms have not been confirmed on periodontitis. We assessed the relationship between ApaI, BsmI, and FokI VDR polymorphisms and the risk of severe chronic periodontitis among Japanese adult men. Materials and Methods:In a cross-sectional study, we examined 97 unrelated healthy Japanese men (mean age: 45.6 years, range: 22-59). A clinical examination was performed at a worksite health checkup, and information was obtained using a self-reported questionnaire. DNA was extracted from whole blood, and the VDR ApaI, BsmI, and FokI polymorphisms were genotyped using polymerase chain reaction. Results: F-carriers of FokI VDR polymorphisms were less likely to develop severe chronic periodontitis than non-F-carriers (p = 0.09). The ApaI and BsmI VDR polymorphisms did not show significant differences in the alleles or genotypes between the subjects with or without severe chronic periodontitis. The haplotype analysis of the three combined VDR polymorphisms revealed that the Abf homozygote had a notably higher prevalence of severe chronic periodontitis than the others, and adjustments for age, smoking status, number of teeth present, and prevalence of diabetes did not change this association (OR = 7.5; 95% CI = 1.6-34.4; p = 0.01). Conclusion:The VDR haplotype constructed from the ApaI, BsmI, and FokI polymorphisms is related to the risk of severe chronic periodontitis in Japanese men.

No abstract