Rapid direct analysis of retinyl palmitate (vitamin A) in fortified vegetable oils by HPLC-FLD.

Large-scale food fortification of vegetable oils with vitamin A has been implemented successfully for decades in numerous African and Asian countries, contributing demonstrably to reductions in vitamin A deficiency. For these programmes, reliable and validated analytical data are essential to demonstrate compliance with legal standards and fortification levels. Commonly, many analytical laboratories use a saponification method for the quantitative analysis of retinyl palmitate (the mostly used form of vitamin A for fortification) in fortified oils, which implies a multiple-step procedure with long analysis times and the potential risk of analyte loss. The aim of the present study was to develop and validate a direct High-performance Liquid Chromatography (HPLC) method that reduces these sample preparation steps, leading to the cost- and time-efficient quantification of retinyl palmitate in fortified oils. Oil samples are dissolved into the HPLC solvents, then injected directly into a common C18 column, and subsequently detected by a fluorescence detector. The limit of quantification (1.0 mg retinyl palmitate kg-1) and the working range of 1.0-100 mg retinyl palmitate kg-1 with a linearity of R2 = 0.9989 are appropriate to analyse fortified oil samples. The method also showed adequate precision (RSD between 1.1% and 3.1%) and recoveries (86-103%) at two different concentration levels. The accuracy of the direct HPLC method was additionally proven by the comparison of spiked samples with two external laboratories that used the saponification method. The robustness of the method was confirmed by the analysis of various spiked edible oils. The HPLC column is not deteriorated by the lipid matrix and shows excellent stability and long lifetime. Also, 9-cis-retinyl palmitate formed mainly by light exposure could be detected by this method. The direct HPLC method is a well-suited alternative to the saponification method for the rapid and reliable routine analysis of fortified oil samples.

Synthesis and Biochemical Evaluation of Noncyclic Nucleotide Exchange Proteins Directly Activated by cAMP 1 (EPAC1) Regulators.

Exchange proteins directly activated by cAMP (EPAC) play a central role in various biological functions, and activation of the EPAC1 protein has shown potential benefits for the treatment of various human diseases. Herein, we report the synthesis and biochemical evaluation of a series of noncyclic nucleotide EPAC1 activators. Several potent EPAC1 binders were identified including 25g, 25q, 25n, 25u, 25e, and 25f, which promote EPAC1 guanine nucleotide exchange factor activity in vitro. These agonists can also activate EPAC1 protein in cells, where they exhibit excellent selectivity toward EPAC over protein kinase A and G protein-coupled receptors. Moreover, 25e, 25f, 25n, and 25u exhibited improved selectivity toward activation of EPAC1 over EPAC2 in cells. Of these, 25u was found to robustly inhibit IL-6-activated signal transducer and activator of transcription 3 (STAT3) and subsequent induction of the pro-inflammatory vascular cell adhesion molecule 1 (VCAM1) cell-adhesion protein. These novel EPAC1 activators may therefore act as useful pharmacological tools for elucidation of EPAC function and promising drug leads for the treatment of relevant human diseases.

Adsorption of phosphorus with calcium alginate beads containing drinking water treatment residual.

Aluminum-based drinking water treatment residuals (DWTR) were encapsulated by alginate to develop a pelletized media (DWTR-CA beads) for phosphorus (P) adsorption. The beads were successfully manufactured to uniform size and shape requirements. The effects of DWTR powder concentration and particle size, and bead mean size on P adsorption, were investigated. The DWTR was found to be an important component in the beads for P adsorption, while the calcium alginate shell contributed little for P adsorption. The maximum P adsorption capacity of the DWTR-CA bead was 19.42 mg P/g wet beads, corresponding to a bead diameter of 3.1 ± 0.2 mm and DWTR concentration of 2% (1% weight/volume (W/V)), mg/mL). The adsorption data fit well with the intra-particle diffusion model and the pseudo-second-order kinetic model, while both the Langmuir and Freundlich adsorption isotherms described the adsorption process well. Furthermore, the study on the effect of pH on P adsorption showed that acidic conditions resulted in a better P adsorption and the DWTR-CA beads have the function of pH neutralization. The findings of this study show that the DWTR-CA beads are a promising adsorbent/substrate for P removal.

Influence of group III/IV muscle afferents on small muscle mass exercise performance: a bioenergetics perspective.

KEY POINTS: This investigation assessed the influence of group III/IV muscle afferents on small muscle mass exercise performance from a skeletal muscle bioenergetics perspective. Group III/IV muscle afferent feedback was attenuated with lumbar intrathecal fentanyl during intermittent isometric single-leg knee-extensor all-out exercise, while 31 P-MRS was used to assess skeletal muscle bioenergetics. Attenuation of group III/IV muscle afferent feedback improved exercise performance during the first minute of exercise, due to an increase in total ATP production with no change in the ATP cost of contraction. However, exercise performance was not altered during the remainder of the protocol, despite a sustained increase in total ATP production, due to an exacerbated ATP cost of contraction. These findings reveal that group III/IV muscle afferents directly limit exercise performance during small muscle mass exercise, but, due to their critical role in maintaining skeletal muscle contractile efficiency, with time, the benefit of attenuating the muscle afferents is negated. ABSTRACT: The direct influence of group III/IV muscle afferents on exercise performance remains equivocal. Therefore, all-out intermittent isometric single-leg knee-extensor exercise and phosphorous magnetic resonance spectroscopy (31 P-MRS) were utilized to provide a high time resolution assessment of exercise performance and skeletal muscle bioenergetics in control conditions (CTRL) and with the attenuation of group III/IV muscle afferent feedback via lumbar intrathecal fentanyl (FENT). In both conditions, seven recreationally active men performed 60 maximal voluntary quadriceps contractions (MVC; 3 s contraction, 2 s relaxation), while knee-extensor force and 31 P-MRS were assessed during each MVC. The cumulative integrated force was significantly greater (8 ± 6%) in FENT than CTRL for the first minute of the all-out protocol, but was not significantly different for the second to fifth minutes. Total ATP production was significantly greater (16 ± 21%) in FENT than CTRL throughout the all-out exercise protocol, due to a significantly greater anaerobic ATP production (11 ± 13%) in FENT than CTRL with no significant difference in oxidative ATP production. The ATP cost of contraction was not significantly different between FENT and CTRL for the first minute of the all-out protocol, but was significantly greater (29 ± 34%) in FENT than in CTRL for the second to fifth minutes. These findings reveal that group III/IV muscle afferents directly limit exercise performance during small muscle mass exercise, but, due to their critical role in maintaining skeletal muscle contractile efficiency, with time, the benefit from muscle afferent attenuation is negated.

Bioenergetics and ATP Synthesis during Exercise: Role of Group III/IV Muscle Afferents.

PURPOSE: The purpose of this study was to investigate the role of the group III/IV muscle afferents in the bioenergetics of exercising skeletal muscle beyond constraining the magnitude of metabolic perturbation. METHODS: Eight healthy men performed intermittent isometric knee-extensor exercise to task failure at ~58% maximal voluntary contraction under control conditions (CTRL) and with lumbar intrathecal fentanyl to attenuate group III/IV leg muscle afferents (FENT). Intramuscular concentrations of phosphocreatine (PCr), inorganic phosphate (Pi), diprotonated phosphate (H2PO4), adenosine triphosphate (ATP), and pH were determined using phosphorous magnetic resonance spectroscopy (P-MRS). RESULTS: The magnitude of metabolic perturbation was significantly greater in FENT compared with CTRL for [Pi] (37.8 ± 16.8 vs 28.6 ± 8.6 mM), [H2PO4] (24.3 ± 12.2 vs 17.9 ± 7.1 mM), and [ATP] (75.8% ± 17.5% vs 81.9% ± 15.8% of baseline), whereas there was no significant difference in [PCr] (4.5 ± 2.4 vs 4.4 ± 2.3 mM) or pH (6.51 ± 0.10 vs 6.54 ± 0.14). The rate of perturbation in [PCr], [Pi], [H2PO4], and pH was significantly faster in FENT compared with CTRL. Oxidative ATP synthesis was not significantly different between conditions. However, anaerobic ATP synthesis, through augmented creatine kinase and glycolysis reactions, was significantly greater in FENT than in CTRL, resulting in a significantly greater ATP cost of contraction (0.049 ± 0.016 vs 0.038 ± 0.010 mM·min·N). CONCLUSION: Group III/IV muscle afferents not only constrain the magnitude of perturbation in intramuscular Pi, H2PO4, and ATP during small muscle mass exercise but also seem to play a role in maintaining efficient skeletal muscle contractile function in men.

Cortical auditory evoked responses of older adults with and without probable mild cognitive impairment.

OBJECTIVE: Hearing loss has been well-documented as a risk factor for cognitive impairment, but the simple presence of hearing loss is not a sufficient predictor of cognitive decline. Although auditory behavioral research has not revealed an effective indicator of early cognitive impairment, a limited number of studies using cortical auditory evoked potentials (CAEPs) have shown promising evidence of an auditory neurophysiological indicator of early-stage cognitive impairment. The purpose of this study was to examine the P1-N1-P2 complex for indicators of cognitive impairment. METHODS: The latency and amplitude of the P1-N1-P2 complex was measured for two stimuli (pure tone, speech) in two groups: cognitively normal older adults (CNOAs) and older adults with probable mild cognitive impairment (MCI), based on the Montreal Cognitive Assessment. RESULTS: Significantly smaller P2 amplitudes were found for those with probable MCI compared to CNOA across stimulus conditions. Stimulus effects were found for P1 and P2 latency. CONCLUSION: P2 amplitude may be a useful indicator of early-stage cognitive impairment. SIGNIFICANCE: As effective treatments become available, early identification of cognitive impairment can facilitate the prescription of treatment at the earliest juncture. CAEPs have the potential to serve as efficient, non-invasive, cost-effective indicators of future cognitive decline and impairment.

Intrinsic religiousness and spirituality as predictors of mental health and positive psychological functioning in Latter-Day Saint adolescents and young adults.

We investigated the relationships between religiousness and spirituality and various indicators of mental health and positive psychosocial functioning in three separate samples of college students. A total of 898 students at Brigham Young University participated in the three studies. The students ranged in age from 17 to 26 years old, with the average age of 20.9 across all three samples. Our results indicate that intrinsic religiousness, spiritual maturity, and self-transcendence were significantly predictive of better mental health and positive functioning, including lower levels of depression, anxiety, and obsessive-compulsiveness, and higher levels of global self-esteem, identity integration, moral self-approval, and meaning in life. Intrinsic religiousness was not predictive of shame, perfectionism, and eating disorder symptoms. These findings are consistent with many prior studies that have found religiousness and spirituality to be positively associated with better mental health and positive psychosocial functioning in adolescents and young adults.

Financial impact of the GFC: health care spending across the OECD.

Since the onset of the global financial crisis (GFC), health spending has slowed markedly or fallen in many OECD countries after years of continuous growth. However, health spending patterns across the 34 countries of the OECD have been affected to varying degrees. This article examines in more detail the observed downturn in health expenditure growth, analysing which countries and which sectors of health spending have been most affected. In addition, using more recent preliminary data for a subset of countries, this article tries to shed light on the prospects for health spending trends. Given that public sources account for around three-quarters of total spending on health on average across the OECD, and, in an overall context of managing public deficits, the article focuses on the specific areas of public spending that have been most affected. This study also tries to link the observed trends with some of the main policy measures and instruments put in place by countries. The investigation finds that while nearly all OECD countries have seen health spending growth decrease since 2009, there is wide variation as to the extent of the slowdown, with some countries outside of Europe continuing to see significant growth in health spending. While all sectors of spending appear to have been affected, initial analysis appears to show the greatest decreases has been experienced in pharmaceutical spending and in areas of public health and prevention.

Influence of thermal treatment on nanostructured gold model catalysts.

We fabricated films of Au onto single crystal alumina (Al(2)O(3)(0001)) and nanostructured the surface using a high resolution focused ion beam (FIB) to remove specific regions of the film. The nanostructures consist of lines and orthogonal lines cut into the film, resulting in one- and two-dimensional islands of gold. When these films are heated above 300 °C, small nanoparticles of gold form due to the dewetting of the Au film from the alumina surface. The dimensions of these islands are dictated by the nature of the nanopatterning. The isolated islands generally have the smallest nanoparticles after heating, while the unpatterned film has much larger particles. Sintering is reduced within the nanostructured metal domains due to isolation of Au islands from each other. The evaporation rate is higher within these islands, due to the smaller size of nanoparticles and hence the higher effective vapor pressure over the surface (the Kelvin effect).

Endoscopic brachytherapy for obstructive colorectal cancer.

PURPOSE: Palliation of obstructive colon cancer is often challenging. Treatment options include Yttrium aluminum garnet (YAG) laser, stent placement, and surgical intervention. High-dose-rate intraluminal brachytherapy (HDRILBT) has been used to relieve obstructive symptoms due to rectal, bronchial, and esophageal cancers. In this case report, we document the combined use of YAG laser and HDRILBT for the palliation of obstructive colon cancer at the hepatic flexure, not previously reported in the literature. METHODS AND MATERIALS: The patient in this case report had a large colonic tumor at the hepatic flexure causing near complete obstruction. Stent insertion and surgery were not feasible. YAG laser was used once and 11 days later, two fractions of HDRILBT were given 1 week apart. Under endoscopic vision and fluoroscopic guidance, a 150-cm Teflon catheter was passed through the lumen of the partially obstructed bowel for purposes of HDRILBT. A total dose of 10Gy was delivered at 1cm from the center of the source axis using a high-dose-rate afterloader. RESULTS: After treatment with the first fraction of HDRILBT, the tumor size decreased and the colonic lumen was significantly more patent. The patient's symptoms were significantly relieved after two fractions. Her weight increased and she was medically fit enough to undergo further chemotherapy. Further HDRILBT was not indicated. The calculated biological effective dose for the total HDRILBT treatments was well below the dose tolerances for acute effects for normal colonic tissue. CONCLUSION: HDRILBT should be considered as a possible treatment option for obstructive colon cancers when stent placement or surgery is not possible.

Effects of dietary omega-3 fatty acid supplementation on endothelium-dependent vasodilation in patients with chronic heart failure.

We investigated the effects of omega-3 fatty acids administration on endothelium-dependent vasodilation in patients > or =65 years old who received treatment for chronic heart failure (CHF). Twenty patients (mean age 73 years; 15 men) with grade II and III CHF who were on maximal medical management were recruited. Patients were randomized in a double-blind, crossover fashion to 6 weeks of omega-3 fatty acid (1.8 g ecosapentaenoic acid and 1.2 g docosahexaenoic acid) or olive oil. Forearm blood flow (FBF) responses to incremental doses of intra-arterial sodium nitroprusside, acetycholine (ACH), angiotensin-II, and N(g)-nitro-L-arginine methyl ester were assessed by venous occlusion strain gauge plethysmography. The endothelium-dependent increase in FBF was greater in response in ACH infusion after omega-3 fatty acid administration (7.9, 95% confidence interval [CI] 4.81 to 11.08 to 11.3, 95% CI 7.31 to 15.23 arbitrary units (p <0.05) compared with baseline (7.95, 95% CI 4.8 to 11.08 arbitrary units) and olive oil administration (7.27, 95% CI 4.66 to 9.88 arbitrary units) (p = NS for both). Neither omega-3 fatty acid nor olive oil altered endothelium-independent vasodilation in response to infusion of sodium nitroprusside, nor did they influence vasoconstrictor responses to angiotensin-II or N(g)-nitro-L-arginine methyl ester. Dietary omega-3 fatty acid supplementation was accompanied by an increase in FBF response to ACH, which represents enhanced endothelium-dependent vasodilation in CHF. Further studies are warranted to assess the mechanism responsible for the beneficial actions of omega-3 fatty acids in CHF.

Green tea epigallocatechin-3-gallate (EGCG) modulates amyloid precursor protein cleavage and reduces cerebral amyloidosis in Alzheimer transgenic mice.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder pathologically characterized by deposition of beta-amyloid (Abeta) peptides as senile plaques in the brain. Recent studies suggest that green tea flavonoids may be used for the prevention and treatment of a variety of neurodegenerative diseases. Here, we report that (-)-epigallocatechin-3-gallate (EGCG), the main polyphenolic constituent of green tea, reduces Abeta generation in both murine neuron-like cells (N2a) transfected with the human "Swedish" mutant amyloid precursor protein (APP) and in primary neurons derived from Swedish mutant APP-overexpressing mice (Tg APPsw line 2576). In concert with these observations, we find that EGCG markedly promotes cleavage of the alpha-C-terminal fragment of APP and elevates the N-terminal APP cleavage product, soluble APP-alpha. These cleavage events are associated with elevated alpha-secretase activity and enhanced hydrolysis of tumor necrosis factor alpha-converting enzyme, a primary candidate alpha-secretase. As a validation of these findings in vivo, we treated Tg APPsw transgenic mice overproducing Abeta with EGCG and found decreased Abeta levels and plaques associated with promotion of the nonamyloidogenic alpha-secretase proteolytic pathway. These data raise the possibility that EGCG dietary supplementation may provide effective prophylaxis for AD.

Production of 8-epi prostaglandin F(2alpha) in human platelets during administration of organic nitrates.

OBJECTIVES: The objective of this study was, using isolated platelets as a surrogate for vascular cells, to examine the effect of nonintermittent organic nitrate administration on 8-epi prostaglandin F(2alpha) (8-epi PGF(2alpha)) content and the effect of concurrent oral ascorbate administration. BACKGROUND: The long-term efficacy of organic nitrates is hampered by hemodynamic tolerance, which develops during continuous administration. This has been associated with altered production of superoxide and nitric oxide, as well as oxidative stress. This effect may be ameliorated by the co-administration of antioxidants. METHODS: Ten healthy male subjects received nitroglycerin (NTG) transdermally at a dosage of 0.4 mg/h for 3 days with ascorbate or lactose (1.2 g/day). After two weeks washout, the treatment was repeated with reversed ascorbate/lactose. Platelets were prepared by centrifugation and esterified 8-epi PGF(2alpha) measured at the start and finish of each treatment by immunoassay. RESULTS: Nitroglycerin, in the absence of supplemental ascorbate, was associated with a significant increase in platelet-esterified 8-epi PGF(2alpha), from 32.9 (95% confidence interval [CI] 11.8 to 54.0) to 51.0 (95% CI 16.3 to 85.7) pg/mg protein (p < 0.05). Co-administration of ascorbate with NTG resulted in a significant decrease in 8-epi PGF(2alpha) production, from 38.8 (95% CI 24.9 to 52.7) to 19.0 (95% CI 13.5 to 24.5) pg/mg protein (p < 0.05). CONCLUSIONS: Continuous NTG administration results in an increase in platelet-esterified 8-epi PGF(2alpha), a free radical and cyclooxygenase-dependent compound. This is reversed by co-administration of the free radical scavenger ascorbate. Whether this increase is merely a marker for increased oxidative stress or a mediator of oxidative injury contributing to the hemodynamic changes observed in nonintermittent organic nitrate treatment has yet to be resolved.

Platelet nitric oxide and superoxide release during the development of nitrate tolerance: effect of supplemental ascorbate.

BACKGROUND: The therapeutic benefits that accompany the continuous administration of organic nitrates are attenuated by the development of tolerance to the compounds. Altered superoxide production and NO bioavailability have been implicated in contributing to the development of tolerance, an effect that may be ameliorated by the administration of antioxidants. METHODS AND RESULTS: We studied the effect of 3 days of continuous transdermal administration of nitroglycerin (NTG) (10 mg/24 hours) on platelet free radical (NO and superoxide anion [O2*-] activity) with and without coadministration of supplemental ascorbate (2.4 g/24 hours). NAD(P)H oxidase activity, nitric oxide synthase (NOS) activity, and cyclic guanosine monophosphate (cGMP) content were also assessed. Radial artery pressure pulse waveforms were used to track the hemodynamic actions of NTG. Three days of NTG/placebo was associated with a significant increase in platelet NO and O2*- production from 1.0+/-1.17 to 2.52+/-0.88 pmol/10(8) platelets and 13.2+/-4.8 to 72.5+/-34.4 pmol/10(8) platelets, respectively (P<0.01 for both). These changes were accompanied by increased platelet NADH oxidase activity from 47.9+/-11.0 to 65.3+/-13.6 pmol O2*- min/mg protein and cGMP content from 0.60+/-0.10 to 0.89+/-0.16 pmol/10(9) platelets (P<0.05 for both). Administration of NTG/ascorbate attenuated both NO and O2*- release in platelets. CONCLUSIONS: Three days of continuous transdermal administration of NTG was accompanied by increased platelet NO and O2*- production and NADH oxidase activity that was suppressed by coadministration of oral ascorbate. Although a significant degree of tolerance would be expected during continuous nitrate administration, a residual hemodynamic action could be identified by arterial pulse contour analysis.