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Brian S. Fadely - One of the best experts on this subject based on the ideXlab platform.
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Regional variations and drivers of mercury and selenium concentrations in Steller sea lions.
The Science of the total environment, 2020Co-Authors: Lorrie D. Rea, Judith M. Castellini, J.p. Avery, Brian S. Fadely, Vladimir N. Burkanov, Michael J. Rehberg, Todd M. O'haraAbstract:Abstract Mercury (Hg) can be neurotoxic to mammals and impact reproduction, whereas selenium (Se) is an important antioxidant known to ameliorate some adverse effects of Hg. Total Hg concentrations ([THg]) were measured in Lanugo (pelage grown in utero) of 812 Steller sea lion (Eumetopias jubatus) pups across Alaska and Russia to assess fetal exposure during late gestation. The molar ratio of total Se to THg (TSe:THg) was determined in whole blood collected from 291 pups. Stable isotope ratios of carbon and nitrogen were measured in sections of vibrissae (whiskers, n = 498) and in Lanugo (n = 480) of pups grown during late gestation to track diet variations between adult females that can drive Hg and Se exposure during this critical fetal development period. Lanugo [THg] ranged from 1.4 to 73.7 μg/g dry weight with the lowest median [THg] in Southeast Alaska. Pups from the Western Aleutian Islands had higher median Lanugo [THg] than pups from other metapopulations in Alaska. Over 25% of pups in the Western Aleutian Islands had [THg] above published risk thresholds (20 μg/g) for other mammals. Whole blood molar TSe:THg was significantly lower in the Western Aleutian Islands and in some parts of the Central Aleutian Islands with higher molar ratios found in the Eastern Aleutian Islands and Central Gulf of Alaska. This suggests a limitation on potential protective functions of Se in the western regions with the highest relative [THg]. The Central Aleutian Island pups with [THg] over 20 μg/g had higher δ15N ratios than pups with lower [THg] suggesting dams consuming higher trophic level prey is a key driver for Hg exposure. However, regional differences likely reflect variability in diet of the dam during gestation and in Hg food web dynamics between oceanic regimes east and west of key passes in the Aleutian Islands.
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Stress-related and reproductive hormones in hair from three north Pacific otariid species: Steller sea lions, California sea lions and northern fur seals
Conservation physiology, 2020Co-Authors: Mandy Keogh, Angela Gastaldi, Patrick Charapata, Sharon R. Melin, Brian S. FadelyAbstract:Assessing the physiological impact of stressors in pinnipeds is logistically challenging, and many hormones are altered by capture and handling, limiting the utility of metabolically active tissues. Hair is increasingly being used to investigate stress-related and reproductive hormones in wildlife populations due to less-invasive collection methods, being metabolically inert once grown and containing multiple biomarkers of ecological interest. We validated enzyme immunoassays for measuring aldosterone, cortisol, corticosterone, and testosterone in Lanugo (natal hair grown in utero) samples collected from Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), and northern fur seals (Callorhinus ursinus). We applied laboratory validation methods including recovery of added mass, parallelism and dilution linearity. We found no effects due to differences in alcohol- versus detergent-based cleaning methods. Further, there were no significant differences in hormone concentrations in hair samples collected immediately after the molt and the subsequent samples collected over 1 year, indicating steroid hormones are stable once deposited into pinniped hair. We found no sex differences in any hormone concentrations, likely due to the Lanugo being grown in utero and influenced by maternal hormone concentrations. For Steller sea lion and California sea lion pups, we found hormone concentrations significantly differed between rookeries, which warrants future research. Hair provides a novel tissue to explore the intrinsic or extrinsic drivers behind hormone measurements in otariids, which can be paired with multiple health-related metrics to further investigate possible drivers of physiological stress.
D J Van Neste - One of the best experts on this subject based on the ideXlab platform.
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Human hair production by scalp samples grafted onto nude mice. Biochemical data on normal human hair and the genetic defect trichothiodystrophy.
Journal of dermatological science, 1994Co-Authors: B De Brouwer, J Föhles, D J Van NesteAbstract:The authors report on a laboratory model for continuous production of human hair during long periods of time. This study shows that the amino acid composition of hairs collected in situ from human scalp was similar to that of terminal hairs produced by the donors' scalp follicles grafted and maintained onto nude mice. A similar experiment was performed with scalp samples from a foetus with trichothiodystrophy (TTD). The amino acid analysis of TTD Lanugo hairs and of the TTD shafts produced by grafted scalp specimens was consistent with findings published in the literature: severe decrease of cys (< 50% of control values) and moderate decrease of thr and pro (80% of control values or less) with an increase of ala-asp-ile-leu-lys-met-phe (120% of control values or more). These changes indicate a decrease of high sulphur proteins (HSP) and consequently a relative increase of keratins. Furthermore, when foetal scalp samples were grafted, the Lanugo hairs transformed into terminal hairs along with normal initiation of melanisation. Hence, keratin and HSP gene expression and regulation of melanogenesis in the normal and genetically defective TTD human hair follicle grafts appear to be independent of systemic host-related factors, at least during a 6 months follow-up period after grafting. The present experimental evidence further supports conclusions gained from previous assays with normal and TTD variant scalp grafts, i.e. that the nude mouse bearing human scalp specimens may serve as a clinically relevant laboratory model for evaluating regulation of normal and abnormal gene expression in the hair follicle under well controlled experimental conditions.
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Human hair production by scalp samples grafted onto nude mice. Biochemical data on normal human hair and the genetic defect trichothiodystrophy
Journal of Dermatological Science, 1994Co-Authors: B De Brouwer, J Föhles, D J Van NesteAbstract:Abstract The authors report on a laboratory model for continuous production of human hair during long periods of time. This study shows that the amino acid composition of hairs collected in situ from human scalp was similar to that of terminal hairs produced by the donors' scalp follicles grafted and maintained onto nude mice. A similar experiment was performed with scalp samples from a foetus with trichothiodystrophy (TTD). The amino acid analysis of TTD Lanugo hairs and of the TTD shafts produced by grafted scalp specimens was consistent with findings published in the literature: severe decrease of cys (
Viktor V Kalinchuk - One of the best experts on this subject based on the ideXlab platform.
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Hair mercury concentrations in the spotted seal (Phoca largha) pups from the Sea of Japan.
Environmental science and pollution research international, 2018Co-Authors: Alexey M. Trukhin, Viktor V KalinchukAbstract:This publication presents the results of a study of the total mercury (THg) concentration in the fetal hair (Lanugo) of the young spotted seals inhabiting the Peter the Great Bay, Sea of Japan. We analyzed samples from pups that were collected in 2014–2017 at the seal breeding grounds. The concentration of total mercury was determined by atomic absorption spectrometry. The concentration of THg ranged from 1.52 to 6.68 μg/g dry weight. Mercury concentration in the Lanugo exceeds that found in the environment (bottom sediments, sea water) and in other animals inhabiting the Bay. At the same time, the level was generally lower than that found in young seals of most other pinniped species (Steller sea lion Eumetopias jubatus, Northern fur seal Callorhinus ursinus, Harbor seal Phoca vitulina richardsi, Northern elephant seal Mirounga angustirostris, California sea lion Zalophus californianus) from the North Pacific.
B De Brouwer - One of the best experts on this subject based on the ideXlab platform.
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Human hair production by scalp samples grafted onto nude mice. Biochemical data on normal human hair and the genetic defect trichothiodystrophy.
Journal of dermatological science, 1994Co-Authors: B De Brouwer, J Föhles, D J Van NesteAbstract:The authors report on a laboratory model for continuous production of human hair during long periods of time. This study shows that the amino acid composition of hairs collected in situ from human scalp was similar to that of terminal hairs produced by the donors' scalp follicles grafted and maintained onto nude mice. A similar experiment was performed with scalp samples from a foetus with trichothiodystrophy (TTD). The amino acid analysis of TTD Lanugo hairs and of the TTD shafts produced by grafted scalp specimens was consistent with findings published in the literature: severe decrease of cys (< 50% of control values) and moderate decrease of thr and pro (80% of control values or less) with an increase of ala-asp-ile-leu-lys-met-phe (120% of control values or more). These changes indicate a decrease of high sulphur proteins (HSP) and consequently a relative increase of keratins. Furthermore, when foetal scalp samples were grafted, the Lanugo hairs transformed into terminal hairs along with normal initiation of melanisation. Hence, keratin and HSP gene expression and regulation of melanogenesis in the normal and genetically defective TTD human hair follicle grafts appear to be independent of systemic host-related factors, at least during a 6 months follow-up period after grafting. The present experimental evidence further supports conclusions gained from previous assays with normal and TTD variant scalp grafts, i.e. that the nude mouse bearing human scalp specimens may serve as a clinically relevant laboratory model for evaluating regulation of normal and abnormal gene expression in the hair follicle under well controlled experimental conditions.
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Human hair production by scalp samples grafted onto nude mice. Biochemical data on normal human hair and the genetic defect trichothiodystrophy
Journal of Dermatological Science, 1994Co-Authors: B De Brouwer, J Föhles, D J Van NesteAbstract:Abstract The authors report on a laboratory model for continuous production of human hair during long periods of time. This study shows that the amino acid composition of hairs collected in situ from human scalp was similar to that of terminal hairs produced by the donors' scalp follicles grafted and maintained onto nude mice. A similar experiment was performed with scalp samples from a foetus with trichothiodystrophy (TTD). The amino acid analysis of TTD Lanugo hairs and of the TTD shafts produced by grafted scalp specimens was consistent with findings published in the literature: severe decrease of cys (
Das Krishna - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of trace elements in grey seals throughout the lactation period
2011Co-Authors: Habran Sarah, Pomeroy P. P., Debier Cathy, Das KrishnaAbstract:The effects of reproduction and maternal investment (i.e. milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of Cd, Pb, Hg, Cr, Ni, V, Zn, Cu, Fe, Ca and Se throughout lactation in a top predator from the North Sea, the grey seal (Halichoerus grypus). Trace element levels were measured in blood and milk of 21 mother-pup pairs in early and late lactation. Maternal hair and natal fur (Lanugo) were also collected and analyzed. Trace element levels in blood decreased according to the following pattern: Fe > Ca > Zn > Se > Cu > Hg > Pb > Cr > V in mothers and pups. Cd and Ni were not detected in blood. The substantial levels measured in Lanugo indicate nevertheless that all trace elements (including Cd and Ni) were transferred to offspring through the placenta. In maternal hair, Pb levels (~ 2.2 mg/kg dw) were relatively high in comparison with other phocid species. All trace elements, except Cd, were detected in the milk showing a transmammary transfer to offspring, especially for elements such as Ca, Se, V, Ni and Pb. Hg showed the highest levels in blood (up to 0.25 mg/kg ww) and hair (up to 21 mg/kg dw) from the non-essential and toxic metals measured. Levels of Hg and essential elements (Ca, Fe, Zn, Cu and Se) in blood and milk showed significant variations throughout the lactation period. Therefore, physiological processes such as lactation affect trace element levels in tissues of mother and pup elephant seals. Such processes and its relationship to body condition should be considered carefully when interpreting trace element levels in the framework of biomonitoring.Peer reviewe
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Dynamics of trace elements in grey seals throughout the lactation period
2011Co-Authors: Habran Sarah, Pomeroy P. P., Debier Cathy, Das KrishnaAbstract:peer reviewedaudience: researcher, professionalThe effects of reproduction and maternal investment (i.e. milk transfer) on trace element levels remain poorly understood in marine mammals. We examined the blood dynamics of Cd, Pb, Hg, Cr, Ni, V, Zn, Cu, Fe, Ca and Se throughout lactation in a top predator from the North Sea, the grey seal (Halichoerus grypus). Trace element levels were measured in blood and milk of 21 mother-pup pairs in early and late lactation. Maternal hair and natal fur (Lanugo) were also collected and analyzed. Trace element levels in blood decreased according to the following pattern: Fe > Ca > Zn > Se > Cu > Hg > Pb > Cr > V in mothers and pups. Cd and Ni were not detected in blood. The substantial levels measured in Lanugo indicate nevertheless that all trace elements (including Cd and Ni) were transferred to offspring through the placenta. In maternal hair, Pb levels (~ 2.2 mg/kg dw) were relatively high in comparison with other phocid species. All trace elements, except Cd, were detected in the milk showing a transmammary transfer to offspring, especially for elements such as Ca, Se, V, Ni and Pb. Hg showed the highest levels in blood (up to 0.25 mg/kg ww) and hair (up to 21 mg/kg dw) from the non-essential and toxic metals measured. Levels of Hg and essential elements (Ca, Fe, Zn, Cu and Se) in blood and milk showed significant variations throughout the lactation period. Therefore, physiological processes such as lactation affect trace element levels in tissues of mother and pup elephant seals. Such processes and its relationship to body condition should be considered carefully when interpreting trace element levels in the framework of biomonitoring
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Maternal transfer of trace metals to offspring in grey seals
2010Co-Authors: Habran Sarah, Debier Cathy, Pomeroy Paddy, Das KrishnaAbstract:Marine mammals may display high heavy metal levels in their tissues, which raises the question of the importance of toxic metal transfer from mother to offspring. Some lactating female phocids fast during the suckling period. This fasting period involves not only an important mobilization of energy reserves, but also mobilization of potentially associated contaminants. We studied maternal transfer of trace metals to offspring in the grey seal (Halichoerus grypus). Trace metal concentrations were measured in whole blood, milk and hair of mother-pup pairs in early and late lactation. Metal levels in blood decreased according to the following pattern: Fe > Zn > Se > Cu > Hg > Pb > Cr > V in mothers and pups. Cd and Ni were not detected and V, Cr and Pb levels were very low in maternal and pup blood. However, Ni and Pb levels were detected in the milk showing a transmammary transfer of these metals. Hg levels in blood and milk were higher than levels of previous metals and levels varied significantly throughout lactation. The increasing maternal levels over lactation were likely due to the remobilization of energy reserves during fasting and milk production in mothers causing a Hg release in blood. All metals were detected in hair and Lanugo according to the following pattern: Fe > Zn > Hg > Cu > Se > Ni > V > Pb > Cd > Cr in mothers and Zn > Fe > Hg > Se > Cu > Pb > Ni > V > Cr > Cd in pups. Pb levels were relatively high in comparison with other phocid species. Only Hg showed a significant relationship between hair/Lanugo and blood levels. This study highlights (i) a transplacental and transmammary transfer of metals in grey seals, and shows that (ii) physiological processes such as lactation and/or fasting can modify trace metal levels in the blood of mothers and pups.Peer reviewe
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Maternal transfer of trace metals to offspring in grey seals
2010Co-Authors: Habran Sarah, Debier Cathy, Pomeroy Paddy, Das KrishnaAbstract:peer reviewedaudience: researcher, professionalMarine mammals may display high heavy metal levels in their tissues, which raises the question of the importance of toxic metal transfer from mother to offspring. Some lactating female phocids fast during the suckling period. This fasting period involves not only an important mobilization of energy reserves, but also mobilization of potentially associated contaminants. We studied maternal transfer of trace metals to offspring in the grey seal (Halichoerus grypus). Trace metal concentrations were measured in whole blood, milk and hair of mother-pup pairs in early and late lactation. Metal levels in blood decreased according to the following pattern: Fe > Zn > Se > Cu > Hg > Pb > Cr > V in mothers and pups. Cd and Ni were not detected and V, Cr and Pb levels were very low in maternal and pup blood. However, Ni and Pb levels were detected in the milk showing a transmammary transfer of these metals. Hg levels in blood and milk were higher than levels of previous metals and levels varied significantly throughout lactation. The increasing maternal levels over lactation were likely due to the remobilization of energy reserves during fasting and milk production in mothers causing a Hg release in blood. All metals were detected in hair and Lanugo according to the following pattern: Fe > Zn > Hg > Cu > Se > Ni > V > Pb > Cd > Cr in mothers and Zn > Fe > Hg > Se > Cu > Pb > Ni > V > Cr > Cd in pups. Pb levels were relatively high in comparison with other phocid species. Only Hg showed a significant relationship between hair/Lanugo and blood levels. This study highlights (i) a transplacental and transmammary transfer of metals in grey seals, and shows that (ii) physiological processes such as lactation and/or fasting can modify trace metal levels in the blood of mothers and pups
