Taxonomic Patterns in the Triglyceride Structure of Natural Fats

Natural fats from different organisms frequently have similar fatty acid composition but different triglyceride structures. These differences often fall into clear-cut taxonomic patterns when the distribution of fatty acids between the sn-1, sn-2-, and sn-3-positions of the glycerol is considered. Such characteristic fatty acid distribution patterns can frequently be used to distinguish commerical fats and oils from different sources, i. e. fish oil from whale oil, or virgin olive oil from the re-esterified product.     

15,18,21,24-triacontatetraenoic and 15,18,21,24,27-triacontapentaenoic acids: New C30 fatty acids from the marine spongeCliona celata

The marine sponseCliona celata contains 3.5% 30∶4ω6 and 7.0% 30∶5w3 in its total fatty acids. These C₃₀ polyunsaturated structures are unknown in other living organisms. Both acids occur mainly as phosphatidylserine esters.     

Use of gaze for real-time mood regulation: Effects of age and attentional functioning.

Older adults show positive preferences in their gaze toward emotional faces, and such preferences appear to be activated when older adults are in bad moods. This suggests that age-related gaze preferences serve a mood regulatory role, but whether they actually function to improve mood over time has yet to be tested. We investigated links between fixation and mood change in younger and older adults, as well as the moderating role of attentional functioning. Age × Fixation × Attentional Functioning interactions emerged such that older adults with better executive functioning were able to resist mood declines by showing positive gaze preferences. Implications for the function of age-related positive gaze preferences are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simultaneous detection of single molecules and singulated ensembles of molecules enables immunoassays with broad dynamic range

We report a method for combining the detection of single molecules (digital) and an ensemble of molecules (analog) that is capable of detecting enzyme label from 10(-19) M to 10(-13) M, for use in high sensitivity enzyme-linked immunosorbent assays (ELISA). The approach works by capturing proteins on microscopic beads, labeling the proteins with enzymes using a conventional multistep immunosandwich approach, isolating the beads in an array of 50-femtoliter wells (Single Molecule Array, SiMoA), and detecting bead-associated enzymatic activity using fluorescence imaging. At low concentrations of proteins, when the ratio of enzyme labels to beads is less than ～1.2, beads carry either zero or low numbers of enzymes, and protein concentration is quantified by counting the presence of "on" or "off" beads (digital regime). (1) At higher protein concentrations, each bead typically carries multiple enzyme labels, and the average number of enzyme labels present on each bead is quantified from a measure of the average fluorescence intensity (analog regime). Both the digital and analog concentration ranges are quantified by a common unit, namely, average number of enzyme labels per bead (AEB). By combining digital and analog detection of singulated beads, a linear dynamic range of over 6 orders of magnitude to enzyme label was achieved. Using this approach, an immunoassay for prostate specific antigen (PSA) was developed. The combined digital and analog PSA assay provided linear response over approximately four logs of concentration ([PSA] from 8 fg/mL to 100 pg/mL or 250 aM to 3.3 pM). This approach extends the dynamic range of ELISA from picomolar levels down to subfemtomolar levels in a single measurement.     

Plasma Levels of 14:0, 16:0, 16:1n-7, and 20:3n-6 are Positively Associated,but 18:0 and 18:2n-6 are Inversely Associated with Markers of Inflammation in Young Healthy Adults

Inflammation is a recognized risk factor for the development of chronic diseases, such as type 2 diabetes and atherosclerosis. Evidence suggests that individual fatty acids (FA) may have distinct influences on inflammatory processes. The goal of this study was to conduct a cross-sectional analysis to examine the associations between circulating FA and markers of inflammation in a population of young healthy Canadian adults. FA, high-sensitivity C-reactive protein (hsCRP), and cytokines were measured in fasted plasma samples from 965 young adults (22.6 ± 0.1 years). Gas chromatography was used to measure FA. The following cytokines were analyzed with a multiplex assay: regulated upon activation normal T cell expressed and secreted (RANTES/CCL5), interleukin 1-receptor antagonist (IL-1Ra), interferon-γ (IFN-γ), interferon-γ inducible protein 10 (IP-10), and platelet-derived growth factor β (PDGF-ββ). Numerous statistically significant associations (p < 0.05, corrected for multiple testing) were identified between individual FA and markers of inflammation using linear regression. Myristic (14:0), palmitic (16:0), palmitoleic (16:1n-7), and dihomo-γ-linolenic (20:3n-6) acids were positively associated with all markers of inflammation. In contrast, stearic acid (18:0) was inversely associated with hsCRP and RANTES, and linoleic acid (18:2n-6) was inversely associated with hsCRP, RANTES and PDGF-ββ. In conclusion, our results indicate that specific FA are distinctly correlated with various markers of inflammation. Moreover, the findings of this study suggest that FA profiles in young adults may serve as an early indicator for the development of future complications comprising an inflammatory component.     

Effect of parasympathetic denervation of liver and pancreas on glucose kinetics in man

The study aim was to investigate the role of the parasympathetic nervous system in the control of glucose tolerance in man. Glucose kinetics were determined during an oral glucose tolerance test (OGTT) in six subjects with truncal vagotomies and six control subjects. Basal plasma glucose levels in the two groups were equal; however, 20 to 40 minutes after the OGTT, glucose was higher in vagotomized compared with control subjects (P < .02). There were no differences in insulin levels between the subjects. Glucagon decreased after the OGTT in the controls, whereas in the vagotomized subjects it increased transiently and did not decrease beyond basal levels. There was no difference in basal hepatic glucose production, but suppression was greater in controls in the first 10 minutes (P < .01). Gut-derived glucose appearance increased faster and to a higher level (56.0 +/- 8 v 29.7 +/- 2.9 mumol/kg/min, P < .02) in vagotomized subjects. There were no differences in the metabolic clearance rate of glucose between the two groups. It is concluded that parasympathetic innervation of the pancreas is essential for suppression of glucagon secretion during hyperglycemia. However, abnormal glucose tolerance in vagotomized subjects is primarily due to rapid gut glucose absorption, with the denervated parasympathetic system playing only a minor role.     

Positional distribution of fatty acids in depot triglycerides of aquatic animals

Stereospecific triglyceride analyses were performed on fats of the following animals: five aquatic invertebrates, five freshwater fish, six marine fish, three marine birds, two amphibia, two seals, a whale, and a marine turtle. The distribution of faty acids was asymmetrical in most cases. A formula is presented which describes the general tendencies of fatty acid distribution in many animal fats, and some special rules which modify this formula are stated. Visit sponsored by a grant from the National Institutes of Health (AM-06011).     

Quantitative gas-liquid chromatography of triglycerides

To determine optimum operating conditions, an extensive study was made of the variables affecting quantitative recovery and resolution of model triglyceride mixtures. Parameters investigated included: flash heater temperature, carrier gas flow rate, type of carrier gas, column length, glass and metal columns, temperature program rate, linearity of detector response, physical design of gas chromatograph, and molecular species of triglyceride. Results indicate that with optimum operating conditions, triglyceride molecular weights through trierucin can be quantitatively analyzed. Accurate calibration is essential, since quantitative response factors vary somewhat with operating conditions, triglyceride carbon number, and the chromatograph used. Cocoa butter and rat adipose tissue triglycerides have been quantitatively analyzed by this technique. Presented at the AOCS meeting in Houston, Texas, 1965.