The Experts below are selected from a list of 20796 Experts worldwide ranked by ideXlab platform
Desmond J Tobin - One of the best experts on this subject based on the ideXlab platform.
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quantitative mapping of human Hair graying and reversal in relation to life stress
bioRxiv, 2021Co-Authors: Ayelet Rosenberg, Shannon Rausser, Junting Ren, Eugene V Mosharov, Gabriel Sturm, Todd R Ogden, Purvi Patel, Rajesh K Soni, Clay Lacefield, Desmond J TobinAbstract:Hair graying is a universal hallmark of aging believed to be linked to psychological stress. Here we develop a novel approach to quantitatively profile natural graying events along individual human Hair shafts, resulting in a quantifiable physical timescale of Hair pigmentation patterns (HPPs). Using this approach, we quantify rare events of white/gray Hairs that naturally regain pigmentation within days to weeks, thereby quantitatively defining the reversibility of graying in healthy, unmedicated individuals. Proteomic analysis shows that graying is marked by the upregulation of proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining Hair pigmentation profiling and proteomics at the single Hair Level, we also report Hair graying and its reversal occurring in parallel with behavioral and psychological stressors. A computational simulation suggests a threshold-based mechanism for the temporary reversibility of graying. Quantitatively mapping HPPs in humans provides an opportunity to longitudinally examine the influence of life exposures on biological aging.
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quantitative mapping of human Hair graying and reversal in relation to life stress
bioRxiv, 2020Co-Authors: Ayelet Rosenberg, Shannon Rausser, Junting Ren, Eugene V Mosharov, Gabriel Sturm, Todd R Ogden, Purvi Patel, Rajesh K Soni, Clay Lacefield, Desmond J TobinAbstract:Hair graying is a universal hallmark of chronological and biological aging, but its mechanisms are insufficiently understood and its potential reversibility in humans has not been quantitatively examined. Moreover, while psychological stress accelerates human biological aging and triggers Hair graying in animals, no prior study has longitudinally examined the stress-to-Hair graying connection in humans. Here we develop a novel approach to quantitatively profile natural graying events and their associated proteomic signatures along individual human Hair shafts, resulting in a quantifiable physical timescale of Hair pigmentation patterns (HPPs). Using this approach, we quantify rare events of white/gray Hairs that naturally regain pigmentation within days to weeks, in 14 individuals across sex, ethnicities, ages, and body regions, thereby quantitatively defining the reversibility of graying across Hairs in healthy, unmedicated individuals. Proteomic analysis of matched dark (i.e. pigmented) and white Hairs replicated across two independent experiments show that graying is marked by the upregulation of proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining Hair pigmentation profiling and proteomics at the single Hair Level, we also report Hair graying and its reversal occurring in parallel with behavioral and psychological stressors. A computational simulation of life-long and stress-induced Hair graying suggests a threshold-based mechanism for the episodic instability of HF pigmentation and the temporary reversibility of graying. Our results show how quantitatively mapping HPPs in humans can provide an opportunity to examine the modifiability of biological aging in relation to life exposures.
Huihua Deng - One of the best experts on this subject based on the ideXlab platform.
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correlations of Hair Level with salivary Level in cortisol and cortisone
Life Sciences, 2018Co-Authors: Quan Zhang, Zheng Chen, Shenghuo Chen, Juxia Wang, Weiwen Wang, Huihua DengAbstract:Abstract Aims Contrary findings exist on the consistency between Hair cortisol and salivary cortisol in assessing the basal activity of the hypothalamic-pituitary-adrenal (HPA) axis. The mismatches in temporal characteristic and the indices of Hair and salivary cortisol might be potential reasons for the inconsistency. The aim of this study was to investigate the consistency between Hair and salivary Levels in cortisol and cortisone by directly examining the correlation between Hair Level and salivary Level with different temporal characteristics (acute, short-term and long-term Levels) and reflecting different HPA functions (basal Level and reactivity Level) in the well-matched time span. Main methods A longitudinal design within a five-week period was conducted in a sample of 44 healthy female college students (mean age: 18.8 yrs.; age range: 18–22 yrs) of Han nationality with the exclusion criteria, such as use of oral contraceptives or glucocorticoids and bleached Hairs, etc. Four saliva samples (awakening, awakening + 30 min, awakening + 4 h and awakening + 9 h) were collected from an identical participant on three separate days with an interval of one week and 1-cm Hair segment nearest to the scalp was collected two weeks later after completing saliva collection. Cortisol and cortisone in saliva and Hair were simultaneously measured with high performance liquid chromatography tandem mass spectrometry. Key findings There were significantly moderate correlations in cortisol and cortisone between Hair Level and three-day average of single-day salivary Level, but low to moderate correlations between Hair Level and single-point and single-day salivary Level. Hair cortisol and cortisone were unrelated to single-day Level and three-day average of diurnal slope and cortisol awakening response of salivary cortisol and cortisone, respectively. Significance The considerable consistency between Hair Level and long-term salivary Level in cortisol and cortisone implies that cortisol and cortisone in Hair are valid biomarkers of cumulative exposure of cortisol and cortisone to retrospectively reflect long-term basal activity of the HPA system.
Gilbert Pepin - One of the best experts on this subject based on the ideXlab platform.
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determination of endogenous Levels of ghb in human Hair are there possibilities for the identification of ghb administration through Hair analysis in cases of drug facilitated sexual assault
Journal of Analytical Toxicology, 2003Co-Authors: Jean Pierre Goulle, Marjorie Cheze, Gilbert PepinAbstract:We have developed a GC-MS-MS assay for GHB in human Hair. Five milligrams of washed Hair were hydrolyzed by 1M or 0.01M NaOH before a liquid-liquid extraction with ethyl acetate under acidic conditions. GHB-d(6) was used as the internal standard. TMS derivatives were formed before injection. TBDMS derivatives were used in cases of strong chromatographic interferences or in a confirmatory procedure. Analysis of basal Levels of GHB in 61 drug-free donors gave the following results: the mean measured concentration for blond Hair was 0.60 ng/mg (n = 12), SD = 0.19 ng/mg, and extreme figures were in the range 0.35-0.95 ng/mg. For brown Hair, the mean measured concentration was 0.90 ng/mg (n = 30), SD = 0.42 ng/mg, and extreme figures 0.41-1.86 ng/mg. For black Hair, the mean measured concentration was 0.90 ng/mg (n = 19), SD = 0.37 ng/mg, and extreme figures 0.32-1.54 ng/mg, showing no significant differences depending on Hair color. Analysis of basal Levels of GHB of 12 or more specimens in segmented Hair showed a mean concentration of 1.22 ng/mg (0.31-8.4 ng/mg) and a relative standard deviation for each individual ranging from 6.75% to 37.98%. GHB was administered to a healthy 53-year-old white male (light brown Hair) at oral dosages of 30, 45, and 60 mg/kg. Beard Hair was collected just before administration and 24 h after (and each day for one week for the last dose), and a 7.5-cm scalp Hair lock was collected 7 days after the last dose. A rise in GHB concentration was observed in beard Hair for the 45 and 60 mg/kg dosages with a maximum at 24 h, whereas no change was observed for the 30 mg/kg dosage. Scalp Hair was segmented into 3-mm long segments. The three proximal last segments showed significantly (0.0005 < p < 0.005) different concentrations of GHB (1.22, 1.27, and 1.66 ng/mg, respectively) when compared with the basal physiological Level of GHB in this same person (mean = 0.62 ng/mg, SD = 0.15 ng/mg). A case of daily GHB abuse during bodybuilding allowed us to determine a concentration of GHB of 14 ng/mg, in a 2-cm long segment (black Hair). A case of rape under the influence of GHB was documented through Hair analysis (black Hair) and positive analysis of the glass she used. Sampled 7 days after the sexual assault, the three last 3-mm long proximal segments tested for GHB exhibited concentrations of 3.1-5.3 and 4.3 ng/mg, respectively, whereas the mean physiological Level determined in this woman was 0.71 ng/mg, SD = 0.17 ng/mg. The authors advise a two-step Hair sampling as evidence of GHB consumption: the first sample at the time of exposure to show the contamination by sweat of the proximal segment in case of recent administration with a significant rise of Hair Level at the root, and the second after at least 3 or 4 weeks to avoid this contamination and determine the Levels incorporated in the Hair matrix before, during, and after the exposure.
Ayelet Rosenberg - One of the best experts on this subject based on the ideXlab platform.
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quantitative mapping of human Hair graying and reversal in relation to life stress
bioRxiv, 2021Co-Authors: Ayelet Rosenberg, Shannon Rausser, Junting Ren, Eugene V Mosharov, Gabriel Sturm, Todd R Ogden, Purvi Patel, Rajesh K Soni, Clay Lacefield, Desmond J TobinAbstract:Hair graying is a universal hallmark of aging believed to be linked to psychological stress. Here we develop a novel approach to quantitatively profile natural graying events along individual human Hair shafts, resulting in a quantifiable physical timescale of Hair pigmentation patterns (HPPs). Using this approach, we quantify rare events of white/gray Hairs that naturally regain pigmentation within days to weeks, thereby quantitatively defining the reversibility of graying in healthy, unmedicated individuals. Proteomic analysis shows that graying is marked by the upregulation of proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining Hair pigmentation profiling and proteomics at the single Hair Level, we also report Hair graying and its reversal occurring in parallel with behavioral and psychological stressors. A computational simulation suggests a threshold-based mechanism for the temporary reversibility of graying. Quantitatively mapping HPPs in humans provides an opportunity to longitudinally examine the influence of life exposures on biological aging.
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quantitative mapping of human Hair graying and reversal in relation to life stress
bioRxiv, 2020Co-Authors: Ayelet Rosenberg, Shannon Rausser, Junting Ren, Eugene V Mosharov, Gabriel Sturm, Todd R Ogden, Purvi Patel, Rajesh K Soni, Clay Lacefield, Desmond J TobinAbstract:Hair graying is a universal hallmark of chronological and biological aging, but its mechanisms are insufficiently understood and its potential reversibility in humans has not been quantitatively examined. Moreover, while psychological stress accelerates human biological aging and triggers Hair graying in animals, no prior study has longitudinally examined the stress-to-Hair graying connection in humans. Here we develop a novel approach to quantitatively profile natural graying events and their associated proteomic signatures along individual human Hair shafts, resulting in a quantifiable physical timescale of Hair pigmentation patterns (HPPs). Using this approach, we quantify rare events of white/gray Hairs that naturally regain pigmentation within days to weeks, in 14 individuals across sex, ethnicities, ages, and body regions, thereby quantitatively defining the reversibility of graying across Hairs in healthy, unmedicated individuals. Proteomic analysis of matched dark (i.e. pigmented) and white Hairs replicated across two independent experiments show that graying is marked by the upregulation of proteins related to energy metabolism, mitochondria, and antioxidant defenses. Combining Hair pigmentation profiling and proteomics at the single Hair Level, we also report Hair graying and its reversal occurring in parallel with behavioral and psychological stressors. A computational simulation of life-long and stress-induced Hair graying suggests a threshold-based mechanism for the episodic instability of HF pigmentation and the temporary reversibility of graying. Our results show how quantitatively mapping HPPs in humans can provide an opportunity to examine the modifiability of biological aging in relation to life exposures.
Quan Zhang - One of the best experts on this subject based on the ideXlab platform.
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correlations of Hair Level with salivary Level in cortisol and cortisone
Life Sciences, 2018Co-Authors: Quan Zhang, Zheng Chen, Shenghuo Chen, Juxia Wang, Weiwen Wang, Huihua DengAbstract:Abstract Aims Contrary findings exist on the consistency between Hair cortisol and salivary cortisol in assessing the basal activity of the hypothalamic-pituitary-adrenal (HPA) axis. The mismatches in temporal characteristic and the indices of Hair and salivary cortisol might be potential reasons for the inconsistency. The aim of this study was to investigate the consistency between Hair and salivary Levels in cortisol and cortisone by directly examining the correlation between Hair Level and salivary Level with different temporal characteristics (acute, short-term and long-term Levels) and reflecting different HPA functions (basal Level and reactivity Level) in the well-matched time span. Main methods A longitudinal design within a five-week period was conducted in a sample of 44 healthy female college students (mean age: 18.8 yrs.; age range: 18–22 yrs) of Han nationality with the exclusion criteria, such as use of oral contraceptives or glucocorticoids and bleached Hairs, etc. Four saliva samples (awakening, awakening + 30 min, awakening + 4 h and awakening + 9 h) were collected from an identical participant on three separate days with an interval of one week and 1-cm Hair segment nearest to the scalp was collected two weeks later after completing saliva collection. Cortisol and cortisone in saliva and Hair were simultaneously measured with high performance liquid chromatography tandem mass spectrometry. Key findings There were significantly moderate correlations in cortisol and cortisone between Hair Level and three-day average of single-day salivary Level, but low to moderate correlations between Hair Level and single-point and single-day salivary Level. Hair cortisol and cortisone were unrelated to single-day Level and three-day average of diurnal slope and cortisol awakening response of salivary cortisol and cortisone, respectively. Significance The considerable consistency between Hair Level and long-term salivary Level in cortisol and cortisone implies that cortisol and cortisone in Hair are valid biomarkers of cumulative exposure of cortisol and cortisone to retrospectively reflect long-term basal activity of the HPA system.
