ABSTRACTBackgroundFoot sole plantar pressure generates transient but habitual cutaneous ischemia, which is even more exacerbated in atypical gait patterns. Thus, adequate post‐occlusive reactive hyperaemia (PORH) is necessary to maintain skin health. Plantar pressure regional variance during daily tasks potentially generates region‐specific PORH, crucial for ischemic defence.AimsThe current work investigated regional PORH across the human foot sole resulting from stance‐like loading.Materials & MethodsA loading device equipped with an in‐line laser speckle contrast imager measured blood flux before, during, and after whole‐foot loading for 2 and 10 min durations at 15% and 50% body weight. Flux was compared between six regions: the heel, lateral arch, medial arch, and fifth, third, and first metatarsals (MT).ResultsBaseline flux was significantly greater in the 1MT and 3MT than all other regions. Loading occluded the heel, 5MT and 3MT more than all other regions. Regional PORH peak, time to peak, area under the curve, and recovery rate were ranked between regions.DiscussionThe 3MT, followed by 5MT, overall had the strongest PORH response, suggesting a heightened protection against ischemia compared to other regions.ConclusionThis work highlights regional variations within a healthy foot, providing a framework for future ulcer risk assessments and interventions to preserve foot health.

2025-01-01·Food Research International

Identification of 3-methoxytyramine as a specific biomarker for beet-sugar-fed honey: A two year surveillance study in South Korea

Article

作者: Mun, Jae-Eun ; Heo, Miran ; Jeong, Hyejeong ; Lee, Woo-Young ; Lee, Su Hee ; Kang, Hui-Seung ; Park, Geon Woo ; Chang, Moon-Ik

Honey is highly vulnerable to food fraud, and there are growing concerns about product authenticity. The commonly used stable carbon isotope ratios in the Calvin (C3) and Hatch-Slack (C4) photosynthesis cycles in plant feed cannot distinguish between beet-sugar-fed honey and natural honey. However, 3-methoxytyramine (3-MT) can be used as specific biomarker for identifying adulteration of beet-sugar-fed honey. In this study, we developed an isotope dilution-liquid chromatography/tandem mass spectrometry method to quantify 3-methoxytyramine (3-MT) in beet-sugar-fed honey. Solid phase extraction was used to quantify 3-MT and to reduce the matrix interference from honey samples. The limit of quantification was 1 μg kg^-1. The accuracy (recovery, %) and precision (relative standard deviation) values, determined in three laboratories, were 100-114 % and 1.25-9.07, respectively. Moreover, 3-MT was detected (1.07-10.7 μgkg^-1) in 144 out of 3046 samples collected from different parts of Republic of Korea over 2021 and 2022. The mean 3-MT concentration of seven honey samples fed with 100 % beet sugar was 5.32 μg kg^-1. The results of our study validated the accuracy and sensitivity of the proposed analytical method was established for quantification of 3-MT in honey samples. Additionally, our study demonstrated that the 3-MT as a reliable biomarker for beet-sugar-fed honey adulteration. Thus, our study presents a novel mass spectrometric approach for authentic honey discrimination with potential application in honey authenticity testing.

2024-03-01·Practical Laboratory Medicine

Development and validation of a simple, fast and sensitive liquid chromatography-tandem mass spectrometry method to establish reference intervals for 24-h urinary free normetanephrine, metanephrine and methoxytyramine

Article

作者: Xu, Runhao ; Zhang, Jie ; Liu, Dan ; Song, Yan

ObjectiveTo develop and validate a rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to detect urinary free metanephrines and methoxytyramine, establishing reference intervals.MethodsUrine samples were diluted with isotope internal standard solution, then analyzed directly using tandem mass spectrometry with multiple reaction monitoring measurement and electrospray ionization source in positive ion mode. Analytical parameters including linearity, lower limit of quantitation, imprecision and accuracy of the method were evaluated. The reference intervals for urinary catecholamine metabolites were established by analyzing 24-h urine samples collected from 81 apparently healthy volunteers.ResultsThe analytical times for MN, NMN, and 3-MT were at 2.79, 2.80, and 2.74 min, respectively. The method displayed excellent linearity (r > 0.99) in the range of 1-1000 ng/mL, with lower limits of quantification (LLOQ) at 0.50 ng/mL for MN and NMN, and 0.25 ng/mL for 3-MT. The method's intra-day and inter-day imprecisions were less than 8 %. The method recovery ranged from 96.8% to 105.8 % for MN, 89.7%-106.4 % for NMN, and 93.5%-106.2 % for 3-MT. No carry-over was observed during the analysis of all analytes. The LC-MS/MS method was used to establish reference intervals in 24-h urine samples from 81 apparently healthy volunteers. There was no association of sex with urinary free metabolites.ConclusionThis study established a novel, fast and sensitive LC-MS/MS method for determining urinary free catecholamine metabolites, which could facilitate screening and diagnosis for catecholamine-related tumors more conveniently and quickly.

100 项与 3-Methoxytyramine 相关的药物交易

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