Neutral Lipid Profiles Research Articles

Rancidity development in oat during industrial processing

To improve the shelf-life of food products rich in lipids, it is important to minimize the lipid oxidation that occurs during processing, since this oxidation not only decreases shelf-life but also induces off-flavors. To evaluate the oxidation of lipids in the production of one β-glucan-rich and one protein-rich food supplement made from oats (Avena sativa), the neutral and polar lipid profile, hexanal content, peroxide value, avenanthramides and lipase activity were measured at all production steps. The concentration of antioxidants in the form of avenanthramides was also investigated. This study shows that oat lipases were fully inactivated in the wet processing part of the processing line, and the total lipid content per dry weight increased with the progression of steps toward the oat protein product. Processing had no apparent effect on avenanthramide levels. Lipid oxidation markers increased in certain processing steps. The most significant increase in hexanal and peroxide values could be seen in the spray-drying step of the process, while a much smaller increase was seen for the drum-drying. The main conclusion is that the most important factor to prolong the shelf-life of the product is to minimize the oxidation in the drying step.

Characterization of Neutral Lipids of the Oleaginous Alga Micractinum inermum.

An oleaginous microalga Micractinum inermum isolated from Mariana Lake, AB, Canada was cultured in a 1000 L photobioreactor with an f/2 medium to study its lipid content and neutral lipid profile. Algal biomass was collected at the stationary phase contained a significant amount of lipids (44.2%), as determined by Folch's method. The lipid was fractionated into neutral lipid, glycolipid and phospholipid fractions. The neutral lipid constitutes almost 77.3% of the total lipid species and is mainly composed of triacylglycerols (TAGs) determined by a proton NMR study. UHPLC-HRMS analysis allows us for the first time to identify 81 TAGs in the neutral lipid fraction of M. inermum. The fatty acid acyl side chains were identified based on fragment ions observed in MSMS analysis. TAGs with fatty acid acyl chains 18:1/18:1/18:1, 18:1/18:1/16:0, 18:2/18:1/16:0, and 18:2/18:2/18:0 were the major ones among the identified TAGs. Fatty acid analysis further supports the fact that oleic acid was the major fatty acid present in the neutral lipid fraction of M. inermum constituting 41.7%, followed by linoleic acid at 21.5%, and palmitic acid at 21.2%. The saturated and monounsaturated fatty acids were 67.8% or higher in the lipid fraction. Long-chain fatty acids were only present in a minor quantity. The results clearly demonstrate that M. inermum is an excellent source for TAGs.

Beyond PLFA: Concurrent extraction of neutral and glycolipid fatty acids provides new insights into soil microbial communities

The analysis of phospholipid fatty acids (PLFAs) is one of the most common methods used to quantify the abundance, and analyse the community structure, of soil microbes. The PLFA extraction method can yield two additional lipid fractions—neutral lipids and glycolipids—which potentially hold additional, valuable information on soil microbial communities. Yet its quantitative sensitivity on complete neutral lipid (NLFA) and glycolipid fatty acid (GLFA) profiles has never been validated. In this study we tested (i) if the high-throughput PLFA method can be expanded to concurrently extract complete NLFA and GLFA profiles, as well as sterols, (ii) whether taxonomic specificities of signature fatty acids are retained across the three lipid fractions in pure culture strains, and (iii) whether NLFAs and GLFAs allow soil-specific fingerprinting to the same extent as PLFA analysis. By adjusting the polarity of chloroform with 2% ethanol for solid phase extraction, pure lipid standards were fully fractionated into neutral lipids, glycolipids, and phospholipids. Sterols eluted in the neutral lipid fraction, and a betaine lipid co-eluted with phospholipids. We found consistent taxonomic specificities of fatty acid markers across the three lipid fractions by analysing pure culture extracts representative of soil microbes. Fatty acid profiles from soil extracts, however, showed stronger differences between PLFAs, NLFAs, and GLFAs than between soil types. This indicates that PLFAs and NLFAs signify different community properties (biomass vs. carbon storage, putatively), and that GLFAs are sensitive markers for community traits which behave differently than PLFAs. Although we consistently found high abundances of characteristic sterols in fungal extracts, the PLFA extraction method only yielded miniscule amounts of ergosterol from soil extracts. We argue that concomitant measurement of fatty acid profiles from all three lipid fractions is a low-effort and potentially information-rich addition to the PLFA method, and discuss its applicability for soil microbial community analyses.

Mitochondrial Fatty Acid β-Oxidation Disorders: From Disease to Lipidomic Studies-A Critical Review.

Fatty acid oxidation disorders (FAODs) are inborn errors of metabolism (IEMs) caused by defects in the fatty acid (FA) mitochondrial β-oxidation. The most common FAODs are characterized by the accumulation of medium-chain FAs and long-chain (3-hydroxy) FAs (and their carnitine derivatives), respectively. These deregulations are associated with lipotoxicity which affects several organs and potentially leads to life-threatening complications and comorbidities. Changes in the lipidome have been associated with several diseases, including some IEMs. In FAODs, the alteration of acylcarnitines (CARs) and FA profiles have been reported in patients and animal models, but changes in polar and neutral lipid profile are still scarcely studied. In this review, we present the main findings on FA and CAR profile changes associated with FAOD pathogenesis, their correlation with oxidative damage, and the consequent disturbance of mitochondrial homeostasis. Moreover, alterations in polar and neutral lipid classes and lipid species identified so far and their possible role in FAODs are discussed. We highlight the need of mass-spectrometry-based lipidomic studies to understand (epi)lipidome remodelling in FAODs, thus allowing to elucidate the pathophysiology and the identification of possible biomarkers for disease prognosis and an evaluation of therapeutic efficacy.

Comparative analysis of lipid profiles and flavor composition of marinated eggs from different species

This study compared lipid profiles and volatile composition in marinated eggs from different species (chicken, quail, and pigeon) using LC-ESI-MS/MS and GC-MS, respectively. The three marinated eggs showed significant differences in phosphatidylcholine, phosphatidylethanolamine (PE) and neutral lipid profiles of the three marinated eggs. Pigeon-eggs contained the highest content of PE but the lowest content of triglycerides. Seventy-six potential lipid metabolites such as Cer(d18:1/21:0), DG(15:0/18:2), and PE-O(16:1/18:2) were selected for the discrimination of all three groups. Pigeon-eggs contained the highest contents of C18:2 and C22:6, as well as n-3 and n-6 PUFA than quail-eggs and chicken-eggs. Major compounds including 2-Nonanone, 1-Octen-3-ol, cyclic octaatomic sulfur have greatly contributed to the distinction of eggs from different species. The highest levels of aldehydes, acids and ketones were found in chicken-eggs. This study reported that lipidomic and volatile composition analysis are promising approaches for discriminating of marinated eggs from different species

Effect of sucrose on the fatty acid metabolism of adventitious root cultures in vitro of Stevia rebaudiana

In this study, the effect of sucrose on the neutral lipid profile of adventitious root cultures of Stevia rebaudiana was evaluated. The cultures were obtained employing a roller bottle system. In this system, Schott-type flasks were used, which contained Murashige and Skoog liquid medium at 33.3% strength (MS/3) supplemented with 30, 60, and 80 g L-1 of sucrose, respectively, and 10.7 mM 1-naphthaleneacetic acid (NAA). The spectroscopic analyzes showed that the portion of polyunsaturated fatty acids (PUFAs) was highest in roots treated with 30 g L-1 of sucrose. The spectrometric analyzes showed that the palmitic acid was found to be present in relatively higher amounts in the roots submitted to the MS/3-30 g L-1 (31.9%) and MS/3-60 g L-1 (29.5%) sucrose treatments, and lower in the treatment with MS/3-80 g L-1 (28.8%) of sucrose. Also, the treatment using 30 g L-1 of sucrose was the best for obtaining unsaturated fatty acids (UFAs) in the culture, with a relative percentage of 62.9%. Our results indicate that the MS medium that received 30 g L-1 of sucrose induced a lesser abiotic stress condition, which favored PUFAs production in the adventitious root cultures of S. rebaudiana.

Growth performance and fatty acid tissue profile in gilthead seabream juveniles fed with different phospholipid sources supplemented in low-fish meal diets

The aim of the present study was to evaluate the phospholipid requirements for gilthead seabream, fed with low-fish meal diets. A 70-day feeding trial was performed to evaluate the dietary effects of marine versus plant-based phospholipid sources in low-fish meal diets on growth, body composition, liver, muscle and intestinal fatty acid profiles (polar and neutral), as well as liver morphology. Three levels of krill (marine) or soy lecithin (plant) as phospholipid source, at 0.53%, 1% and 2%, were supplemented in diets with 10% fish meal inclusion. The effects were compared to a high-fish meal diet (65%) as a positive control, and a low-fish meal diet without addition of phospholipids as a negative control. Growth, feed and protein efficiency parameters were improved by the addition of phospholipids in the low-fish meal diets, irrespective of the source, but all parameters were lower compared to the positive control. Krill phospholipid supplementation showed optimal results at 0.5% levels and soybean lecithin supplementation at 1% level. Significant differences by the phospholipid supplementation were found in both the neutral and polar lipid profile in the liver and muscle, while only in the neutral lipids in the intestine. Evaluation of liver histology indicated mild improvement of steatosis symptoms. Overall, our results indicate that phospholipid supplementation in low-fish meal diets can improve the growth and liver status in gilthead seabream juveniles.

Quantitative and Qualitative Analyses of Triacylglycerol Production in the Wild-Type Cyanobacterium Synechocystis sp. PCC 6803 and the Strain Expressing AtfA from Acinetobacter baylyi ADP1

Although cyanobacteria do not possess wax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT), the bacterial enzyme for triacylglycerol (TAG) production, there have been several studies reporting the accumulation of TAG-like compounds in cyanobacteria. In this study, we aimed to evaluate TAG productivity of the ΔrecJ::atfA strain of Synechocystis sp. PCC 6803 generated by inserting atfA encoding WS/DGAT from Acinetobacter baylyi ADP1 into recJ (sll1354), together with the wild type (WT) and the gene-disrupted strain of slr2103 having homology with eukaryotic DGAT2 gene family (Δ2103). Thin-layer chromatography (TLC) of neutral lipids or isolation of the neutral lipid-enriched fraction followed by gas chromatography or liquid chromatography-tandem mass spectrometry was employed for analyses. The ΔrecJ::atfA strain accumulated 0.508 nmol ml-1OD730-1 of TAG after a week of incubation at 100 μmol photons m-2 s-1. The saturated fatty acids C16:0 and C18:0 accounted for about 50% and 20% of the TAG fatty acids, respectively, suggesting that de novo-synthesized fatty acids were preferentially incorporated into TAG molecules. When the neutral lipid profile of the lipid extracts was examined by TLC, a spot located in a slightly lower position compared with the TAG standard was detected in WT but not in the Δ2103 strain. TAG accumulation levels of both strains was only 0.01-0.03 nmol ml-1OD730-1, but the fatty acid composition was substantially different from that of the background. These results suggest that trace amounts of TAG can be produced in Synechocystis cells by enzymes other than Slr2103, and major constituents of the TAG-like spot are unknown lipid species produced by Slr2103.

Safety and efficacy of testosterone for women: a systematic review and meta-analysis of randomised controlled trial data

The benefits and risks of testosterone treatment for women with diminished sexual wellbeing remain controversial. We did a systematic review and meta-analysis to assess potential benefits and risks of testosterone for women. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science for blinded, randomised controlled trials of testosterone treatment of at least 12 weeks' duration completed between Jan 1, 1990, and Dec 10, 2018. We also searched drug registration applications to the European Medicine Agency and the US Food and Drug Administration to identify any unpublished data. Primary outcomes were the effects of testosterone on sexual function, cardiometabolic variables, cognitive measures, and musculoskeletal health. This study is registered with the International Prospective Register of Systematic Reviews (PROSPERO), number CRD42018104073. Our search strategy retrieved 46 reports of 36 randomised controlled trials comprising 8480 participants. Our meta-analysis showed that, compared with placebo or a comparator (eg, oestrogen, with or without progestogen), testosterone significantly increased sexual function, including satisfactory sexual event frequency (mean difference 0·85, 95% CI 0·52 to 1·18), sexual desire (standardised mean difference 0·36, 95% CI 0·22 to 0·50), pleasure (mean difference 6·86, 95% CI 5·19 to 8·52), arousal (standardised mean difference 0·28, 95% CI 0·21 to 0·35), orgasm (standardised mean difference 0·25, 95% CI 0·18 to 0·32), responsiveness (standardised mean difference 0·28, 95% CI 0·21 to 0·35), and self-image (mean difference 5·64, 95% CI 4·03 to 7·26), and reduced sexual concerns (mean difference 8·99, 95% CI 6·90 to 11·08) and distress (standardised mean difference -0·27, 95% CI -0·36 to -0·17) in postmenopausal women. A significant rise in the amount of LDL-cholesterol, and reductions in the amounts of total cholesterol, HDL-cholesterol, and triglycerides, were seen with testosterone administered orally, but not when administered non-orally (eg, by transdermal patch or cream). An overall increase in weight was recorded with testosterone treatment. No effects of testosterone were reported for body composition, musculoskeletal variables, or cognitive measures, although the number of women who contributed data for these outcomes was small. Testosterone was associated with a significantly greater likelihood of reporting acne and hair growth, but no serious adverse events were recorded. Testosterone is effective for postmenopausal women with low sexual desire causing distress, with administration via non-oral routes (eg, transdermal application) preferred because of a neutral lipid profile. The effects of testosterone on individual wellbeing and musculoskeletal and cognitive health, as well as long-term safety, warrant further investigation. Australian National Health and Medical Research Council.

Feeding wet distillers grains plus solubles contributes to sarcoplasmic reticulum membrane instability

Feeding wet distillers grains plus solubles (WDGS) increases polyunsaturated fatty acid (PUFA) levels in beef. It was hypothesised that WDGS in feedlot diets increases PUFA concentration in the sarcoplasmic reticulum (SR) membrane, thereby altering membrane integrity, resulting in more rapid intracellular calcium leakage and improved tenderness. The objective of this study was to evaluate this hypothesis. Ninety-six crossbred steers were fed either a corn-based diet with 0% WDGS or 50% WDGS. Fifteen strip loins per treatment were collected, fabricated into steaks, aged and placed under retail display conditions. Steaks were used to measure tenderness, proteolysis, free calcium concentrations, lipid oxidation, sarcomere length and SR membrane fatty acid, phospholipid lipid, neutral lipid and total lipid profiles. Compared with steaks from steers fed 0% WDGS, steaks from steers fed 50% WDGS were more tender (P < 0.05) and had greater (P < 0.05) free calcium concentrations early post-mortem. Feeding 50% WDGS also tended to increase (P < 0.10) total PUFA concentrations, decrease (P < 0.10) total phospholipid concentration and increase (P < 0.10) total neutral lipid concentration for SR membrane. Steaks from steers fed 0% WDGS had greater (P < 0.05) lipid oxidation (TBARS values) than steaks from steers fed 50% WDGS after extended aging. Although differences in tenderness between the two treatments were detected, there were no corresponding differences (P > 0.10) in sarcomere length or proteolysis. This study showed that feeding WDGS may increase tenderness, possibly by increasing free calcium in muscle early post-mortem. However, the true mechanism that contributes to these differences is still unclear.

Linkage between exotic earthworms, understory vegetation and soil properties in sugar maple forests

The comminuting and soil mixing activities of earthworms can affect soil physical, chemical and biological properties, which in turn can influence plant growth and survival. Accordingly, there is growing concern that the spread of exotic earthworms into northern temperate forests may compromise biodiversity and tree species recruitment. We report on a study where we sampled earthworms, soils, and understory plants in plots established in 40 mature sugar maple stands distributed over 3 areas in the Eastern Townships of Southern Québec (Canada). Earthworms were found in 19 of 40 plots, and earthworm frequency of occurrence (Efo) as well as the complexity of earthworm communities reflected human accessibility to the plots. Plant species richness decreased, and species evenness increased, with Efo. The Efo was related to a decrease in the cover of 5 plant species, and to an increase in the cover of 2 other plant species or plant functional groups. Increasing Efo also correlated with higher soil pH, lower forest floor thickness and lower soil C:N ratio. Among these 3 variables, redundancy analysis (RDA) revealed that soil pH and forest floor thickness correlated with plant community composition. Based on neutral lipid and phospholipid fatty acid profiles, we found that soil bacteria and fungi increased with a decrease in forest floor thickness, bacteria and arbuscular mycorrhizal fungi (AMF) increased with soil pH, whereas actinobacteria and AMF increased with Efo. We discuss the possible mechanisms by which earthworms might directly or indirectly alter understory plant community composition. By considering the location and land use management of each study site, our study provides further evidence that the spread of exotic earthworms in sugar maple stands of Southern Québec may be linked to human activities, with implications for further research and conservation issues.

Changes in lipids and volatile compounds of oat flours and extrudates during processing and storage

Oats is valuable raw material, but it needs to be heat-treated to inactivate lipid degrading enzymes that would deteriorate its sensory quality. The aim was to study if extrusion could replace traditional heat treatment in production of whole meal oats with stable lipids. Flours from non-heat-treated (NHT) oat grains were extruded under four conditions and subjected to 15-week storage. Stability of the extrudates as well as the NHT and heat-treated oat grains were studied for hydrolytic and oxidative reactions by measuring neutral lipid profiles and volatile products. In the NHT oat grains, lipid hydrolysis started immediately after milling, which also promoted lipid oxidation during storage. Enzymatic degradation of lipids could effectively be prevented by extrusion even at the lowest temperature of 70 °C. The extrusion temperature could be increased to 110 °C without subjecting the lipids to non-enzymatic oxidation. However, by increasing the temperature to 130 °C, lipid oxidation was promoted, which also resulted in losses of neutral lipids over time. Hexanoic acid became the major volatile product in oat extrudates during extensive lipid oxidation instead of hexanal, which is a commonly used lipid oxidation indicator. In conclusion, lipids in oat grains could be stabilized by extrusion even at a temperature of 70 °C.

Changes in the lipid profile of Bradybaena similaris (Férussac, 1821) (Gastropoda, Xanthonychidae) during the development of Eurytrema coelomaticum (Giard and Billet, 1892) (Digenea, Dicrocoeliidae)

The effect of experimental exposure of Bradybaena similaris by Eurytrema coelomaticum on the cholesterol and triglycerides total levels circulating in the hemolymph and the neutral lipids in the digestive gland–gonad (DGG) complex of the host snail were studied. In this study, snails were dissected after one, two, and three months of infection to collect the hemolymph and DGG to measure the cholesterol and triacylglycerol levels in the hemolymph and neutral lipid fractions in the tissues. The results for the hemolymph showed that the infection by this trematode resulted in a significant decrease in the concentrations of triacylglycerol during all periods analyzed, as well as, increase in the levels of cholesterol observed after the second and third months of study. This decrease suggests the possible use of triacylglycerol by both parasite and host as alternative substrate in maintaining their energy metabolisms. In parallel, the increase in the contents of cholesterol results from a severe cellular disorganization in snail, especially DGG, as a consequence of the intense plastic processes showed by parasite. Additionally, changes in the neutral lipid profile in the DGG of the infected snails were observed, indicating the importance of these molecules for successful infection.

Serum-induced differentiation of human meibomian gland epithelial cells.

We hypothesize that culturing immortalized human meibomian gland epithelial cells in serum-containing medium will induce their differentiation. The purpose of this investigation was to begin to test our hypothesis, and explore the impact of serum on gene expression and lipid accumulation in human meibomian gland epithelial cells. Immortalized and primary human meibomian gland epithelial cells were cultured in the presence or absence of serum. Cells were evaluated for lysosome and lipid accumulation, polar and neutral lipid profiles, and gene expression. Our results support our hypothesis that serum stimulates the differentiation of human meibomian gland epithelial cells. This serum-induced effect is associated with a significant increase in the expression of genes linked to cell differentiation, epithelium development, the endoplasmic reticulum, Golgi apparatus, vesicles, and lysosomes, and a significant decrease in gene activity related to the cell cycle, mitochondria, ribosomes, and translation. These cellular responses are accompanied by an accumulation of lipids within lysosomes, as well as alterations in the fatty acid content of polar and nonpolar lipids. Of particular importance, our results show that the molecular and biochemical changes of immortalized human meibomian gland epithelial cells during differentiation are analogous to those of primary cells. Overall, our findings indicate that immortalized human meibomian gland epithelial cells may serve as an ideal preclinical model to identify factors that control cellular differentiation in the meibomian gland.

Effects of infection by larvae of Angiostrongylus cantonensis (Nematoda, Metastrongylidae) on the lipid metabolism of the experimental intermediate host Biomphalaria glabrata (Mollusca: Gastropoda)

Experimental infection of Biomphalaria glabrata by Angiostrongylus cantonensis induces significant changes in the concentrations of triacylglycerol and cholesterol in the hemolymph and of neutral lipids in the digestive gonad-gland (DGG) complex of the host snail. In this study, snails were dissected after 1, 2, and 3weeks of infection to collect the hemolymph and DGG and to measure the levels of cholesterol and triacylglycerol in the hemolymph and neutral lipid fractions in the tissues. The results show that infection by this nematode resulted in a significant decrease in the concentrations of both cholesterol and triacylglycerol in the hemolymph of B. glabrata during the parasite's initial ontogenic development period. This reduction indicates the possible use of these molecules by both parasite and host not only as energy substrates but also as structural factors required during development of the parasite's larval stages. In parallel, changes in the neutral lipid profile in the DGG and lipase activity of the infected snails were observed, indicating the importance of these molecules for successful infection.

Second-Generation Antipsychotic Agents: A Review of Safety Profiles

Early clinical trials had suggested a better safety profile for the second-generation antipsychotics (SGAs; e.g. risperidone, olanzapine, quetiapine, aripiprazole) compared to the older first-generation agents (FGAs; e.g. haloperidol and phenothiazines); however, new long-term studies have determined that important adverse events are associated with the use of the SGAs and that their safety profiles differ significantly. This article reviews the most recent publications (September 2007 to September 2011) of long-term studies of antipsychotic pharmacotherapy with a focus on adverse events and tolerability of second-generation antipsychotic medications. A total of 55 studies were included. Most commonly reported adverse events were weight gain, dyslipidemias, glycemic abnormalities, hyperprolactinemia, movement disorders and cardiovascular events. It would appear that overweight patients and those with dyslipidemia or risk factors for cardiovascular disease are candidates for agents such as aripiprazole or ziprasidone, which have neutral lipid and weight gain profiles. Patients who are not comfortable with the potential risk of developing hyperprolactinemia should not be prescribed risperidone as first line therapy. Those who have arrhythmias should not be treated with clozapine or ziprasidone. More challenging it is to make a straight recommendation for a first-line treatment in patients at risk of movement disorders. Severe SGA-induced adverse events including death have been reported in elderly patients affected by dementia. Adolescents appear to be more susceptible to SGAs adverse events. Potential risks and benefits should always be considered for each individual patient prior to therapy initiation in order to minimize discontinuation rates and treatment failure. Keywords: Adverse events, Antipsychotics, Long-term studies, Safety, Second-generation antipsychotics, Tolerability, Glucose, Tardive Dyskinesia, HEMATOLOGICAL, olanzapine

Proinflammatory Cytokine Changes in Clinically Stable, Virologically Suppressed, HIV-Infected Patients Switching From Protease Inhibitors to Abacavir

To the Editor: Excess cardiovascular risk has been observed in HIV-infected patients,1 driven by traditional risk factors such as smoking, hypertension, diabetes, and aging, although therapy-induced hyperlipidemia and HIV-induced proinflammatory state and immune activation seem to play a role.2-4 A recent report from the Data Collection on Adverse Events of Anti-HIV Drugs (DAD) Study, one of the largest cohorts evaluating cardiovascular risk in HIV-infected patients, assessed the associations between nucleoside analogues and myocardial infarction. Contrary to the hypothesis expecting a role for thymidine analogues because of their negative effects on plasma lipids, insulin sensitivity, and limb fat loss, DAD investigators unexpectedly found that the recent use of didanosine and abacavir increased the risk of myocardial infarction by 50% and 90%, respectively.5 These findings were even more surprising as abacavir has a neutral lipid profile, does not interfere with insulin sensitivity, is not associated with limb fat loss in naive patients, and even promotes a fat increase in patients with lipoatrophy switching to abacavir from thymidine analogues.6,7 Although the DAD investigators adjusted the effect of abacavir as much as possible, the possibility of bias cannot definitively be ruled out. However, if abacavir really plays a role in promoting cardiovascular disease, other mechanisms apart from lipid changes, insulin sensitivity, and body fat alterations would have to be involved. Several studies have shown that changes in inflammatory cytokines such as adiponectin and tumor necrosis factor (TNF)-alpha may be related to increased cardiovascular risk in the general population.8-10 More recently, this association has been suggested in HIV-infected patients, mainly those with uncontrolled viral replication before initiating or after discontinuing antiretroviral therapy.1-3 The Nevirapine, Efavirenz and Abacavir (NEFA) trial assessed the relative merits of abacavir, efavirenz, or nevirapine as substitutes for the protease inhibitor (PI) component in stable virologically suppressed patients treated with a first-generation, unboosted PI and willing to simplify their regimen.11 In an intensive metabolic substudy of NEFA,12 we found favorable lipid changes in patients switching to any of the 3 options, namely a decrease in total cholesterol in the abacavir group, an increase in HDL cholesterol, and a decrease in the ratio of total cholesterol (TC) and high-density lipoprotein (HDL) cholesterol (TC:HDL) in the nonnucleoside reverse transcriptase inhibitor (NNRTI) groups.12 In addition, adiponectin and soluble tumor necrosis factor alpha receptor type 2 (sTNFR2) were assessed in baseline and 96-week serum samples adequately stored at −80°C for further laboratory analysis, contemplated in the initial design before the substudy. Plasma adiponectin was determined by radioimmunoassay (Linco Research, St. Charles, MO) with a detection threshold of 1 ng/mL and plasma sTNFR2 by a solid-phase enzyme immunoassay with amplified reactivity (Biosource Europe, Fleurus, Belgium) and a detection threshold of 0.1 ng/mL. In samples from 54 of 90 patients included in the metabolic substudy who continued with the assigned drug up to the end of follow-up (18 abacavir, 19 nevirapine, and 17 efavirenz), an increase in adiponectin levels and a decrease in sTNFR2 were observed in the overall population 96 weeks after the PI switch.12 We now present an analysis of the changes observed in these adipokines according to the antiretroviral regimen received in the NEFA metabolic substudy.

Apolipoprotein‐B subclasses as acceptors of cholesteryl esters transferred by CETP

Five apolipoprotein (apo)-defined apoB-containing lipoprotein (Lp) subclasses designated LpB, LpB:C, LpB:E, LpB:C:E and LpA-II:B:C:D:E are present in human plasma. This study was to determine whether these subclasses functioned equally as acceptors of cholesteryl esters (CE) transferred from high-density lipoproteins (HDL) by CE transfer protein in healthy subjects with normal and mildly increased plasma triglyceride (TG) levels. After 4 h incubation of plasma from 14 subjects at 37 degrees C, apoB-containing lipoproteins were separated from HDL by heparin-Mn++ precipitation and fractionated by immunochemical methods into these five subclasses. The neutral lipid (NL) composition for each subclass was measured by gas chromatography (GC) and compared between 0 h and 4 h. A subclass was considered to be a CE acceptor if its CE content increased more than 5% at 4 h and a non-acceptor if no change was observed. Employing the above definition, TG-rich LpB:C and LpB:E + LpB:C:E functioned as CE acceptors and TG-poor LpB and LpA-II:B:C:D:E as non-acceptors. Both LpB:C and LpB:E + LpB:C:E could only actively accept CE as long as they retained their TG-rich character and displayed neutral lipid profiles similar to those of very low-density lipoproteins (VLDL) and intermediate density lipoproteins (IDL). When, as a result of lipolysis their TG content dropped below 25%, they ceased to function as CE acceptors. In subjects with elevated plasma TG, LpB:C was the dominant CE acceptor, a condition that may have pro-atherogenic consequences. Among the apoB-containing particles, LpB:C and LpB:C:E + LpB:E functioned as CE acceptors while LpB and LpA-II:B:C:D:E did not.

Further Studies on the Neutral Lipid Content in the Feces of BALB/c Mice Infected with Echinostoma caproni as Determined by Silica Gel HPTLC-Densitometry

High performance thin layer chromatography was used to determine neutral lipid profiles in the feces of BALB/c mice infected with adults of Echinostoma caproni (Trematoda). An approximate 25 worm burden per host induced changes in the neutral lipid profile of the mice at 3 to 10 weeks post infection (PI) relative to the uninfected controls. Infection caused a significant decrease (Student's t-test, P < 0.05) in the triacylglycerol fraction at 7 weeks PI relative to the uninfected controls. Neutral lipid profiles of feces may serve as an indicator of infection by intestinal trematodes in animals and humans.

High-performance thin-layer chromatographic analysis of neutral lipids in the urine of humans and BALB/c mice

HPTLC analysis has been used to compare neutral lipid profiles in the urine of humans and mice. Neutral lipids and ubiquinone were extracted from urine with chloroform-methanol, 2:1, and determined on silica gel plates with 19 lanes and a concentration zone that were developed with petroleum ether-diethyl ether-glacial acetic acid, 80:20:1. Separated zones were detected with phosphomolybdic acid reagent and quantified by visible mode slit-scanning densitometry at 610 nm. Specific detection reagents were used to confirm the identity of particular lipid classes. The studies confirmed the presence of free sterols, free fatty acids, and triacylglycerols in both human and mouse urine. Methyl esters were found in mouse but not human urine. Hydrocarbons and ubiquinone were present in both human and mouse urine, but were not quantified. Similarities in the urinary neutral lipid profiles of humans and mice suggest that mice may serve as effective models for studies of the effects of infectious and metabolic diseas...