Diagnosis of a new medical condition in pilots may precipitate the end of an aviation career or hobby. For this reason, a barrier exists for pilots to seek medical care due to fear of losing an ...aeromedical certificate. Females represent a growing proportion of pilots in the United States and data on healthcare seeking behavior in this cohort is sparse. We conducted an anonymous online survey of 154 female pilots and 131 female non-pilots in the United States. 83.7% of female pilots have experienced healthcare related aversion compared to 27.5% of non-pilots. 66.7% of female pilots had withheld information from a physician while 46.0% had delayed or forwent medical care due to concern for their medical status. Further studies should be conducted to inform policy change to address pilot healthcare barriers.
To study healthcare avoidance behavior in pilots related to fear of aeromedical certificate loss.
Voluntary participation in an anonymous survey distributed to U.S. pilots.
A total of 3765 pilots ...were included in the analysis. There were 56.1% of pilots (n = 2111) who reported a history of healthcare avoidance behavior due fear for losing their aeromedical certificate. There were 45.7% who sought informal medical care (n = 1721) and 26.8% who misrepresented/withheld information on a written healthcare questionnaire for fear of aeromedical certificate loss (n = 994).
Aircraft pilots may participate in healthcare avoidance behavior related to fear of losing their aeromedical certificate. Further work is necessary to address pilot healthcare avoidance.
► CPPs can be used as functional food ingredients due their antioxidant capacity. ► Pool B of CPPs showed the highest antioxidant capacity (TEAC and ORAC). ► CPPs protected Caco-2 cells against ...H2O2-induced oxidative stress. ► However, they failed to exert protection at mitochondrial level. ► Mechanism of action: metal chelation and modulation of intracellular signaling cascades.
Caseinophosphopeptides can sequester prooxidant metals and scavenge free radicals, and may thus be used as functional food ingredients. The total antioxidant capacity (TEAC and ORAC) of two pools of caseinophosphopeptides (1–3mg/ml), obtained from casein subjected to simulated gastrointestinal digestion (at two different pH values) and selective precipitation, was evaluated to determine dose–response activity. Pool B (which showed the highest antioxidant capacity due to the presence of more antioxidant amino acids) was used to test its cytoprotective effect against H2O2-induced oxidative stress in Caco-2 cells. Caseinophosphopeptides protected the cells against oxidative damage by preserving cell viability, increasing GSH content, inducing catalase enzyme activity, diminishing lipid peroxidation and maintaining a correct cell cycle progression. However, they failed to exert protection at a mitochondrial level (ROS and mitochondrial membrane potential), implying a partial and site-specific effect. Thus, their mechanism of action is not only related to free radical scavenging activity, but also to metal chelation and the modulation of intracellular signaling cascades.
► 7-Ketostigmasterol have a greater proinflammatory potential than 7-ketocholesterol. ► 7-Ketostigmasterol-mediated alterations in cholesterol metabolism are mediated by changes in intracellular ...calcium levels. ► 7-Ketosterol-induced changes in gene expression of enzymes related to cholesterol metabolism.
Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-pre-treated cells, only efflux transporters were down-regulated by 7-ketosterols, showing a greater influence upon ABCG5 expression. Cell-pre-incubation with bradykinin induced changes in ABCG expression levels after 7-ketostigmasterol-incubation; however, the energetic metabolism inhibition reduced NPC1L1 expression only in 7-ketocholesterol-incubated cells. In non-pre-treated cells, HMG-CoA was up-regulated by both 7-ketosterols. However, exposure to inhibitors down-regulated the expression levels, mainly in 7-ketocholesterol-incubated cells. While ACAT expression values in non-pre-treated cells were unchanged, exposure to inhibitors caused down-regulation of mRNA levels. These results suggest that internalization and excretion of 7-ketostigmasterol is probably influenced by Cai, which also could mediate HMGCoA activity in POPs metabolism. However, energetic metabolism and reducing equivalents exert different influences upon the 7-ketosterol internalization.
The aim of this study was to examine the bioaccessibility (maximum soluble concentration in gastrointestinal medium) of total (AsT) and inorganic (AsI) arsenic contents and the effect on them of ...cooking edible seaweed, a food of great interest because of its high As content. An in vitro gastrointestinal digestion (pepsin, pH 2, and pancreatin−bile extract, pH 7) was applied to obtain the mineral soluble fraction of three seaweeds (Hizikia fusiforme, Porphyra sp., and Enteromorpha sp.). AsT was determined by dry-ashing flow injection hydride generation atomic absorption spectrometry. AsI was determined by acid digestion, solvent extraction, and flow injection hydride generation atomic absorption spectrometry. The bioaccessibility of AsI increased significantly after cooking, attaining 73% in Porphyra sp. and 88% in H. fusiforme. For cooked H. fusiforme, the AsI attained in the bioaccessible fraction was 26 μg g-1 seaweed, a concentration that is a warning of the toxicological risk of this food. Keywords: Bioaccessibility; total arsenic; inorganic arsenic; seaweed; cooking
► 7k-Stigmasterol did not cause deleterious effects in Caco-2 cells. ► The sub-cellular target of 7k-cholesterol toxicity seems to be the mitochondria. ► 7k-Stigmasterol demonstrated a capacity to ...reduce toxic effects of 7k-cholesterol.
The biological implications of cholesterol oxidation products have been investigated, though research on plant sterol oxidation products is scarce and in some cases contradictory.
The cytotoxicity of 7keto(k)-stigmasterol versus 7keto(k)-cholesterol at different concentrations (0–120μM) and incubation times (4–24h), in intestinal epithelial cells (Caco-2 cells) was evaluated. The 3-4,5-dimethylthiazol-2-yl-2,3-diphenyl tetrazolium bromide and neutral red uptake tests, mitochondrial membrane potential (ΔΨm), and relative DNA and RNA contents in the cell cycle phases were determined. Possible interaction effects between 7k-derivatives or non-oxidized stigmasterol were monitored.
Endo/lysosomal activity was not impaired by either oxide. 7k-cholesterol showed a deleterious effect upon the mitochondrial compartment after 24h of exposure (120μM), as well as upon ΔΨm when incubated at all concentrations (12/24h). Only cells incubated with 7k-cholesterol (120μM) exhibited a decrease in RNA proportion in the G1 population. The presence of 7k-stigmasterol or stigmasterol with 7k-cholesterol reduced the deleterious metabolic effects upon mitochondrial functionality and integrity and the distribution of RNA contents in G1 and G2 phases. A decrease in the G1 phase proportion was detected in cells exposed to mixtures, without alterations in RNA content. The results obtained indicate the absence of 7k-stigmasterol cytotoxicity in Caco-2 cells and its capacity to reduce 7k-cholesterol toxicity.
Recent studies have expanded the appreciation of the roles of oxysterols triggering inflammatory, immune cytotoxic and apoptotic processes, but have not been considered for proteome analysis. A ...comparative proteomic study in intestinal epithelial cell cultures incubated (60 μM/24 h) with 7keto-cholesterol or 7keto-stigmasterol was performed. The influence of both compounds was studied following the nLC-TripleTOF analysis. Findings were compared to results for control cultures. In the principal component analysis (PCA) of proteome patterns, two components were extracted accounting for 99.8% of the variance in the protein expression. PCA analysis clearly discriminated between the perturbations in the proteome of cell cultures incubated with 7keto-cholesterol and 7keto-stigmasterol. These proteins participate in mitochondrial function, lipid homeostasis, inflammation and immunity and cell proliferation. Remarkable differences between proteome patterns in cell cultures exposed to 7keto-cholesterol and 7keto-stigmasterol affect macrophage migration inhibitory factor, apolipoprotein E, Bcl-2-associated transcription factor and cellular retinoic acid-binding protein. Besides, exposure to 7keto-stigmasterol increased the concentration of ubiquitin-conjugating enzyme E2 and the mitochondrial superoxide dismutase protein. Such findings raise new questions about safety studies and the regulatory potential of oxysterols in the differentiation and function of intestinal and associated immune cells, their response to environmental stimuli and impairment of absorption processes.
•7keto-stigmasterol altered proteins that participate in the immune response(s) and fat partitioning.•7keto-stigmasterol altered Bcl-2 and Cdk1 in a contrasting proteome pattern to that induced by 7keto-cholesterol.•7keto-stigmasterol seems to impair the interaction of the LXRs with their ligands.
•COPs and POPs from natural, processed or metabolic origin can irreversible accumulate in central nervous system.•COPs and POPs exert in vitro cytotoxicity when used up to 1000-fold the potential ...reachable physiological concentration.•COPs and POPs are potential substrates to be metabolized by gut microbiota.•The SOPs’ inflammatory role provides additional reasons for safety studies after long-term consumption of PS.
High dietary intakes of cholesterol together with sedentary habits have been identified as major contributors to atherosclerosis. The latter has long been considered a cholesterol storage disease; however, today atherosclerosis is considered a more complex disease in which both innate and adaptive immune-inflammatory mechanisms as well as bacteria play a major role, in addition to interactions between the arterial wall and blood components. This scenario has promoted nutritional recommendations to enrich different type of foods with plant sterols (PS) because of their cholesterol-lowering effects. In addition to cholesterol, PS can also be oxidized during food processing or storage, and the oxidized derivatives, known as phytosterol oxidation products (POPs), can make an important contribution to the negative effects of both cholesterol and cholesterol oxidation oxides (COPs) in relation to inflammatory disease onset and the development of atherosclerosis. Most current research efforts have focused on COPs, and evaluations of the particular role and physiopathological implications of specific POPs have been only inferential. Appreciation of the inflammatory role described for both COPs and POPs derived from foods also provides additional reasons for safety studies after long-term consumption of PS. The balance and relevance for health of all these effects deserves further studies in humans. This review summarizes current knowledge about the presence of sterol oxidation products (SOPs) in foods and their potential role in inflammatory process and cardiovascular disease.
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•COPs mixture, at optimized conditions, can be use as suitable oxidative stress model C. elegans.•COPs mixture has a toxic action, and this effect requires daf-16 transcriptional ...factor.•Beverages protect against oxidative stress through daf-16 transcriptional factor.•Beverages extend nematode lifespan probably by inhibition of insulin-IGF-1 pathway.
This study evaluates the impact of two plant sterol (PS) enriched fruit beverages (0.6 g /100 ml), without (MfB) or with GOS (MfB-G) (1.2 g/100 ml) on the resistance against oxidative stress induced by non-conventional (cholesterol oxidation products (COPs)) and conventional (H2O2) oxidant compounds, as well as their impact on C. elegans longevity. Nematodes fed with both beverages (0.005–0.25%, v/v) showed similar improved oxidative stress resistance against COPs and H2O2. This effect was dependent on daf-16 transcription factor, although GOS showed an additional beneficial effect independent to daf-16. In addition, both beverages extended nematode lifespan, independently of the presence of GOS. Longevity assays using daf-16 and daf-2 mutant strains revealed that the observed effect was potentially linked to the insulin-IGF-1 pathway. These results provide new in vivo evidence for the potential use of PS enriched fruit beverages in the prevention of oxidative stress underlying many diseases.
Organoarsenical standards and raw and cooked seafood (DORM-2, sole, and Greenland halibut) were subjected to in vitro gastrointestinal digestion to estimate arsenic bioaccessibility (maximum soluble ...concentration in gastrointestinal medium). The in vitro digestion did not modify the chemical form of the organoarsenic species standards. In seafood, bioaccessibility was 67.5−100% for arsenobetaine (AB), 30% for dimethylarsinic acid (DMA), 45% for tetramethylarsonium ion (TETRA), and >50% for trimethylarsine oxide (TMAO). Cooking induced no changes in bioaccessible contents. In addition, transport by Caco-2 cells, an intestinal epithelia model, was evaluated from organoarsenical standards and DORM-2. For standards, transport ranged from 1.7% for AB to 15.5% for TETRA. In DORM-2, transport was observed for only AB (12%), with far higher efficiency than in the case of the standard solution, thus illustrating the interest of using whole foods for studying bioavailability. Keywords: Bioaccessibility; Caco-2 cells; arsenic; seafood; cooking
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