423 research outputs found

    Webuye health and demographic surveillance systems baseline survey of soil-transmitted helmints and intestinal protozoa among children up to five years

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    Background. The intestinal parasitic infections (IPIs) are globally endemic, and they constitute the greatest cause of illness and disease worldwide. Transmission of IPIs occurs as a result of inadequate sanitation, inaccessibility to potable water, and poor living conditions. Objectives. To determine a baseline prevalence of IPIs among children of five years and below at Webuye Health and Demographic Surveillance (HDSS) area in western Kenya. Methods. Cross-sectional survey was used to collect data. Direct saline and formal-ether-sedimentation techniques were used to process the specimens. Descriptive and inferential statistics such as Chi-square statistics were used to analyze the data. Results. A prevalence of 52.3% (417/797) was obtained with the male child slightly more infected than the female (53.5% versus 51%), but this was not significant (χ2=0.482, P>0.05). Giardia lamblia and Entamoeba histolytica were the most common pathogenic IPIs with a prevalence of 26.1% (208/797) and 11.2% (89/797), respectively. Soil-transmitted helminths (STHs) were less common with a prevalence of 4.8% (38/797), 3.8% (30/797), and 0.13% (1/797) for Ascaris lumbricoides, hookworms, and Trichuris trichiura, respectively. Conclusions. Giardia lamblia and E. histolytica were the most prevalent pathogenic intestinal protozoa, while STHs were less common. Community-based health promotion techniques are recommended for controlling these parasites

    Temporal Dynamics of Visual Attention Allocation

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    We often temporally prepare our attention for an upcoming event such as a starter pistol. In such cases, our attention should be properly allocated around the expected moment of the event to process relevant sensory input efficiently. In this study, we examined the dynamic changes of attention levels near the expected moment by measuring contrast sensitivity to a target that was temporally cued by a five-second countdown. We found that the overall attention level decreased rapidly after the expected moment, while it stayed relatively constant before it. Results were not consistent with the predictions of existing explanations of temporal attention such as the hazard rate or the stimulus-driven oscillations. A control experiment ruled out the possibility that the observed pattern was due to biased time perception. In a further experiment with a wider range of cue-stimulus-intervals, we observed that attention level increased until the last 500 ms of the interval range, and thereafter, started to decrease. Based on the performances of a generative computational model, we suggest that our results reflect the nature of temporal attention that takes into account the subjectively estimated hazard rate and the probability of relevant events occurring in the near future

    The Relationship Between Dietary and Supplemental omega-3 Highly Unsaturated Fatty Acid Intake, Blood and Tissue omega-3 Highly Unsaturated Fatty Acid Concentrations, and Colorectal Polyp Recurrence: A Secondary Analysis of the seAFOod Polyp Prevention Trial

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    \ua9 2024 The Author(s). Background: The seAFOod randomized controlled trial tested colorectal polyp prevention by the omega-3 (ω-3) highly unsaturated fatty acid (HUFA) eicosapentaenoic acid (EPA) and aspirin. Variable dietary intake of omega-3 HUFAs (also including docosahexaenoic acid [DHA]) and differential EPA capsule compliance could confound analysis of trial outcomes. Objective: The objective of this study was to investigate the relationship between total (diet and capsule) daily omega-3 HUFA intake, red blood cell (RBC), and rectal mucosa omega-3 HUFA concentrations, and colorectal polyp outcomes in a secondary analysis of the seAFOod trial. Methods: Individual-participant dietary omega-3 HUFA intake (mg/d) was derived from food frequency questionnaires using the European Prospective Investigation into Cancer and Nutrition-Norfolk fatty acid nutrient database. Capsule EPA intake (mg/d) was adjusted for compliance (capsule counting). Fatty acids were analyzed by liquid chromatography-tandem mass spectrometry (as % of total fatty acids). HUFA oxidation was measured using the HUFA/saturated fatty acid (SAT) ratio. The colorectal polyp detection rate (PDR; % with ≥1 polyps) and polyp number per participant were analyzed according to the change in RBC EPA concentrations during the trial (ΔEPA), irrespective of treatment allocation. Results: There was a small degree of HUFA degradation over time in RBC samples stored at > −80oC at research sites (r = −0.36, P<0.001 for HUFA/SAT ratio over time), which did not affect analysis of omega-3 HUFA concentrations. Low baseline EPA concentration, as well as allocation to EPA and % compliance, were associated with a high ΔEPA. Individuals with a ΔEPA value >+0.5% points (ΔEPAhigh), irrespective of allocation to EPA or placebo, had a lower PDR than ΔEPAlow individuals (odds ratio: 0.63; 95% confidence interval [CI]: 0.40, 1.01) and reduced colorectal polyp number (incidence rate ratio: 0.74; 95% CI: 0.54, 1.02). Conclusions: Analysis of the seAFOod trial according to the change in EPA concentration, instead of treatment allocation, revealed a protective effect of EPA treatment on colorectal polyp recurrence (ISRCTN05926847)

    The effect of aspirin and eicosapentaenoic acid on urinary biomarkers of prostaglandin E2 synthesis and platelet activation in participants of the seAFOod polyp prevention trial

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    Urinary prostaglandin (PG) E metabolite (PGE-M) and 11-dehydro (d)-thromboxane (TX) B2 are biomarkers of cyclooxygenase-dependent prostanoid synthesis. We investigated (1) the effect of aspirin 300 mg daily and eicosapentaenoic acid (EPA) 2000 mg daily, alone and in combination, on urinary biomarker levels and, (2) whether urinary biomarker levels predicted colorectal polyp risk, during participation in the seAFOod polyp prevention trial. Urinary PGE-M and 11-d-TXB2 were measured by liquid chromatography-tandem mass spectrometry. The relationship between urinary biomarker levels and colorectal polyp outcomes was investigated using negative binomial (polyp number) and logistic (% with one or more polyps) regression models. Despite wide temporal variability in PGE-M and 11-d-TXB2 levels within individuals, both aspirin and, to a lesser extent, EPA decreased levels of both biomarkers (74% [P ≤.001] and 8% [P ≤.05] reduction in median 11-d-TXB2 values, respectively). In the placebo group, a high (quartile [Q] 2-4) baseline 11-d-TXB2 level predicted increased polyp number (incidence rate ratio [IRR] [95% CI] 2.26 [1.11,4.58]) and risk (odds ratio [95% CI] 3.56 [1.09,11.63]). A low (Q1) on-treatment 11-d-TXB2 level predicted reduced colorectal polyp number compared to placebo (IRR 0.34 [0.12,0.93] for combination aspirin and EPA treatment) compared to high on-treatment 11-d-TXB2 values (0.61 [0.34,1.11]). Aspirin and EPA both inhibit PGE-M and 11-d-TXB2 synthesis in keeping with shared in vivo cyclooxygenase inhibition. Colorectal polyp risk and treatment response prediction by 11-d-TXB2 is consistent with a role for platelet activation during early colorectal carcinogenesis. The use of urinary 11-d-TXB2 measurement for a precision approach to colorectal cancer risk prediction and chemoprevention requires prospective evaluation

    Plasma and rectal mucosal oxylipin levels during aspirin and eicosapentaenoic acid treatment in the seAFOod polyp prevention trial

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    BACKGROUND: Aspirin and eicosapentaenoic acid (EPA) have colorectal polyp prevention activity, alone and in combination. This study measured levels of plasma and rectal mucosal oxylipins in participants of the seAFOod 2 × 2 factorial, randomised, placebo-controlled trial, who received aspirin 300 mg daily and EPA 2000 mg free fatty acid, alone and in combination, for 12 months. METHODS: Resolvin (Rv) E1, 15-epi-lipoxin (LX) A4 and respective precursors 18-HEPE and 15-HETE (with chiral separation) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry in plasma taken at baseline, 6 months and 12 months, as well as rectal mucosa obtained at trial exit colonoscopy at 12 months, in 401 trial participants. RESULTS: Despite detection of S- and R- enantiomers of 18-HEPE and 15-HETE in ng/ml concentrations, RvE1 or 15‑epi-LXA4 were not detected above a limit of detection of 20 pg/ml in plasma or rectal mucosa, even in individuals randomised to both aspirin and EPA. We have confirmed in a large clinical trial cohort that prolonged (12 months) treatment with EPA is associated with increased plasma 18-HEPE concentrations (median [inter-quartile range] total 18-HEPE 0.51 [0.21-1.95] ng/ml at baseline versus 0.95 [0.46-4.06] ng/ml at 6 months [P<0.0001] in those randomised to EPA alone), which correlate strongly with respective rectal mucosal 18-HEPE levels (r = 0.82; P<0.001), but which do not predict polyp prevention efficacy by EPA or aspirin. CONCLUSION: Analysis of seAFOod trial plasma and rectal mucosal samples has not provided evidence of synthesis of the EPA-derived specialised pro-resolving mediator RvE1 or aspirin-trigged lipoxin 15‑epi-LXA4. We cannot rule out degradation of individual oxylipins during sample collection and storage but readily measurable precursor oxylipins argues against widespread degradation
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