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Sample records for hair methylmercury levels

  1. Hair methylmercury levels of mummies of the Aleutian Islands, Alaska

    SciTech Connect

    Egeland, G.M. Ponce, Rafael Bloom, Nicolas S. Knecht, Rick Loring, Stephen Middaugh, John P.

    2009-04-15

    Ancient human hair specimens can shed light on the extent of pre-historic exposures to methylmercury and provide valuable comparison data with current-day exposures, particularly for Indigenous Peoples who continue to rely upon local traditional food resources. Human hair from ancient Aleutian Island Native remains were tested for total and methylmercury (Hg, MeHg) and were radiocarbon dated. The remains were approximately 500 years old (1450 A.D.). For four adults, the mean and median total hair mercury concentration was 5.8 ppm (SD=0.9). In contrast, MeHg concentrations were lower with a mean of 1.2 ppm (SD=1.8) and a median of 0.54 ppm (0.12-3.86). For the five infants, the mean and median MeHg level was 1.2 ppm (SD=1.8) and 0.20 ppm (0.007-4.61), respectively. Segmental analyses showed variations in MeHg concentrations in 1-cm segments, consistent with fluctuations in naturally occurring exposure to mercury through dietary sources. The levels are comparable to or lower than those found in fish and marine mammal-eating populations today who rely far less on subsistence food than pre-historic humans. The findings are, therefore, compatible with increased anthropogenic release of trace metals during the past several centuries.

  2. Monitoring methylmercury during pregnancy: maternal hair predicts fetal brain exposure.

    PubMed

    Cernichiari, E; Brewer, R; Myers, G J; Marsh, D O; Lapham, L W; Cox, C; Shamlaye, C F; Berlin, M; Davidson, P W; Clarkson, T W

    1995-01-01

    Autopsy brains were obtained from infants dying from a variety of causes within a few days of birth in a population exposed to methylmercury in fish. Infant and maternal blood and hair samples were also obtained. The concentration of total mercury in 6 major brain regions were highly correlated with maternal hair levels. This correlation was confirmed by a sequence of comparisons of maternal hair to maternal blood to infant blood and finally to infant brain. The results lend support to the use of maternal hair in assessing fetal exposure to methylmercury in fish-eating populations. PMID:8714874

  3. Methylmercury in hair fisherman for Turkish coasts

    SciTech Connect

    Vural, N.; Uenlue, H.

    1996-10-01

    Environmental methylmercury mainly arises from the methylation of inorganic mercury. The change in speciation of mercury from inorganic to methylated forms is the first step in the aquatic bioaccumulation processes. The bioconcentration factor of methylmercury in fish tissue to that in water is usually between 10{sup 4} and 10{sup 5}. Among seafood, fish products are the main source of methylmercury absorbed by men from the environment. Since Minimata epidemic health injuries and deaths in relation to mercury pollution, environmental and biological monitoring of inorganic and organic mercury species has gained importance through out the world and many reports have been published on the health effects and biological monitoring of mercury compounds including some Mediterranean countries. This study focuses on methylmercury in hair of fisherman living in different geographical Turkish coasts and relationship to eating fish habit. 17 refs., 1 fig., 2 tabs.

  4. Uptake of mercury by the hair of methylmercury-treated newborn mice

    SciTech Connect

    Shi, Chenyang; Lane, A.T.; Clarkson, T.W. )

    1990-04-01

    Human hair has unique advantages in monitoring environmental exposures to methyl-mercury. Using newborn Balb/c mice as a model system, the incorporation of methylmercury into the hair was studied and compared with methylmercury distributions in other tissues. Newborn mice were given intraperitoneal injections of {sup 203}Hg-labeled methylmercury at designated times according to hair growth stages of the mouse. Animals were sacrificed 2 days after dosing. Distribution of mercury in pelt and other tissues was measured. The level of mercury in pelt was found to correlate with hair growth. The amount of mercury in pelt peaked when hair growth was most rapid and the total amount of mercury in pelt was significantly higher than that in other tissues, constituting 40% of the whole body burden. However, when the hair ceased growing, the amount of mercury in pelt dramatically dropped to 4% of whole body burden and mercury concentrations in other tissues except brain were elevated. Autoradiographic studies with tritium-labeled methylmercury demonstrated that methylmercury concentrated in hair follicles in the skin. Within hair follicles and hairs, methylmercury accumulated in regions that are rich in high-sulfur proteins. The uptake of inorganic mercury (administered as HgCl{sub 2}) by pelt was also compared with that of methylmercury. The amount of inorganic mercury found in pelt was less than one-half that of methylmercury in animals with growing hair. Cessation of hair growth did not decrease the inorganic mercury level in pelt to the same extent as in the case of methylmercury.

  5. Interrelationships of blood and hair mercury concentrations in a North American population exposed to methylmercury

    SciTech Connect

    Phelps, R.W.; Clarkson, T.W.

    1980-05-01

    Samples of blood and head hair were analyzed for organic and inorganic mercury from a population which consumed large amonts of fish contaminated with methylmercury. Mercury levels in newly formed hair were found to reflect those in blood with the concentration in hair being approximately 300 times that in blood. Organic and inorganic mercury levels were linearly related in both hair and blood samples, with a mean inorganic/organic ratio of 0.05 in blood and 0.21 in hair, but individual differences were found to exist. In addition, the total mercury concentration and inorganic/organic ratio in hair remained constant with time. Thus, longitudinal analysis of hair samples can provide a simple and accurate method of monitoring continuing exposure and an estimation of peak blood levels months to years after exposure.

  6. Mercury dynamics in hair of rats exposed to methylmercury by synchrotron radiation X-ray fluorescence imaging

    SciTech Connect

    Shimojo, Nobuhiro; Homma-Takeda, Shino; Kumagai, Yoshito

    1997-05-02

    Two dimensional distribution of mercury (Hg) in hair samples of rats exposed to methylmercury (MeHg) was analyzed by synchrotron radiation X-ray fluorescence (SR-XRF) imaging. Experiments with endogenous- and exogenous-model for MeHg exposure revealed that the metal level was obviously higher in the hair cortex after the former exposure whereas a dominant site that Hg distributed after the latter exposure was the cuticle. The method also provided us the Hg profile along the hair length with a single hair obtained by the endogenous model. Thus application of SR-XRF analysis to hair sample would facilitate biological monitoring to not only distinct Hg exposure but also determine its dynamics with only the specimen. 12 refs., 7 figs.

  7. Neurotoxic effects of low-level methylmercury contamination in the Amazonian basin

    SciTech Connect

    Lebel, J.; Mergler, D.; Lucotte, M.; Larribe, F.; Dolbec, J.; Branches, F.; Amorim, M.

    1998-10-01

    Many studies have demonstrated mercury contamination in the Amazonian ecosystem, particularly in fish, a dietary mainstay of populations in this region. The present study focused on potential health effects of this low-level methylmercury exposure. The study was carried out in a village on the Tapajos River, a tributary of the Amazon, on 91 adults inhabitants whose hair mercury levels were inferior to 50 {micro}/g. Performance on a neurofunctional test battery and clinical manifestations of nervous system dysfunction were examined in relation to hair mercury concentrations. Near visual contrast sensitivity and manual dexterity, adjusted for age, decreased significantly with hair mercury levels (P < 0.05), while there was a tendency for muscular fatigue to increase and muscular strength to decrease in women. For the most part, clinical examinations were normal, however, hair mercury levels were significantly higher (P < 0.05) for persons who presented disorganized movements on an alternating movement task and for persons with restricted visual fields. These results suggest dose-dependent nervous system alterations at hair mercury levels below 50 {micro}g/g, previously considered a threshold for clinical effects. The profile of dysfunction in this adult population is consistent with the current knowledge on methylmercury poisoning. The long-term implications of these findings are unknown and need to be addressed.

  8. Hollow fiber liquid phase microextraction combined with graphite furnace atomic absorption spectrometry for the determination of methylmercury in human hair and sludge samples

    NASA Astrophysics Data System (ADS)

    Jiang, Hongmei; Hu, Bin; Chen, Beibei; Zu, Wanqing

    2008-07-01

    Two methods, based on hollow fiber liquid-liquid-liquid (three phase) microextraction (HF-LLLME) and hollow fiber liquid phase (two phase) microextraction (HF-LPME), have been developed and critically compared for the determination of methylmercury content in human hair and sludge by graphite furnace atomic absorption spectrometry (GFAAS). In HF-LPME, methylmercury was extracted into the organic phase (toluene) prior to its determination by GFAAS, while inorganic mercury remained as a free species in the sample solution. In HF-LLLME, methylmercury was first extracted into the organic phase (toluene) and then into the acceptor phase (4% thiourea in 1 mol L - 1 HCl) prior to its determination by GFAAS, while inorganic mercury remained in the sample solution. The total mercury was determined by inductively coupled plasma-mass spectrometry (ICP-MS), and the levels of inorganic mercury in both HF-LLLME and HF-LPME were obtained by subtracting methylmercury from total mercury. The factors affecting the microextraction of methylmercury, including organic solvent, extraction time, stirring rate and ionic strength, were investigated and the optimal extraction conditions were established for both HF-LLLPME and HF-LPME. With a consumption of 3.0 mL of the sample solution, the enrichment factors were 204 and 55 for HF-LLLPME and HF-LPME, respectively. The limits of detection (LODs) for methylmercury were 0.1 μg L - 1 and 0.4 μg L - 1 (as Hg) with precisions (RSDs (%), c = 5 μg L - 1 (as Hg), n = 5) of 13% and 11% for HF-LLLPME-GFAAS and HF-LPME-GFAAS, respectively. For ICP-MS determination of total mercury, a limit of detection of 39 ng L - 1 was obtained. Finally, HF-LLLME-GFAAS was applied to the determination of methylmercury content in human hair and sludge, and the recoveries for the spiked samples were in the range of 99-113%. In order to validate the method, HF-LLLME-GFAAS was also applied to the analysis of a certified reference material of NRCC DORM-2 dogfish

  9. Biological variables in the hair uptake of methylmercury from blood in the Macaque monkey

    SciTech Connect

    Mottet, N.K.; Body, R.L.; Wilkens, V.; Burbacher, T.M.

    1987-04-01

    The total mercury (Hg) in hair and blood of 45 young healthy adult female Macaque fascicularis given 0, 50, 70, or 90 ..mu..g MeHg/kg body wt orally in apple juice daily revealed a close and constant ratio between blood Hg and hair. The amount of hair Hg does not increase with time (maximum period of observation 490 days) at a given dose level. Also the ratio was unchanged between background and subtoxic dose levels. Individuals at a given dose level with a higher-than-average blood level had a proportionately higher hair level. The Macaque blood/hair ratio is markedly lower than that reported for humans. Pregnancy did not have an appreciable effect on the hair mercury level. Review of the known variables in human and Macaque hair growth and structures does not provide an explanation for the difference. They suggest that an as yet unidentified biological variable(s), possibly circumfollicular blood flow, could account for the difference. This ratio difference notwithstanding, controlled studies on Macaque hair such as this add support for the validity of terminal hair as a trace metal exposure indicator.

  10. Hair mercury levels in Amazonian populations: spatial distribution and trends

    PubMed Central

    2009-01-01

    Background Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. Methods The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. Results The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 μg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. Conclusions Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian

  11. Influence of nutrient level on methylmercury content in water spinach.

    PubMed

    Greger, Maria; Dabrowska, Beata

    2010-08-01

    Widely consumed vegetables are often cultivated in sewage waters with high nutrient levels. They can contain high levels of methylmercury (MeHg), because they can form MeHg from inorganic Hg in their young shoots. We determined whether the MeHg uptake and the MeHg formation in the shoots of water spinach (Ipomoea aquatica) were affected by the presence of a high nutrient level in the growth medium. Water spinach shoots were rooted and pretreated in growth medium containing 7% (low) or 70% (high) Hoagland nutrient solution; thereafter, the plants were treated with either 0.02 microM MeHg or 0.2 microM HgCl2 for 3 d. Half the plants were then analyzed for total Hg and MeHg. The remaining plants were transferred to mercury-free medium with low or high nutrient levels and posttreated for 3 days before analysis of total Hg and MeHg in order to measure MeHg formation in the absence of external Hg. The results indicate that nutrient level did not influence MeHg uptake, but that a high nutrient level reduced the distribution of MeHg to the shoots 2.7-fold versus low nutrient level. After treatment with HgCl2, MeHg was found in roots and new shoots but not in old shoots. The MeHg:total-Hg ratio was higher in new shoots than in roots, being 13 times higher at high versus low nutrient levels. Thus, MeHg formation was the same in new shoots independent of inorganic Hg concentration, since the total Hg level decreased at a high nutrient level. PMID:20821626

  12. Evidence of early nervous system dysfunction in Amazonian populations exposed to low-levels of methylmercury.

    PubMed

    Lebel, J; Mergler, D; Lucotte, M; Amorim, M; Dolbec, J; Miranda, D; Arantès, G; Rheault, I; Pichet, P

    1996-01-01

    There is increasing concern about the potential neurotoxic effects of exposure to methylmercury in Amazonian populations due to mercury (Hg) release from gold-mining activities. A preliminary study was undertaken in two villages on the Tapajos River, an effluent of the Amazon, situated over 200 km downstream from the extraction areas. The study population included 29 young adults (< or = 35 years), 14 women and 15 men, randomly chosen from a previous survey. Hair analyses were conducted with cold vapor atomic fluorescence spectrophotometry. Total hair Hg (THg) varied between 5.6 micrograms/g and 38.4 micrograms/gl, with MeHg levels from 72.2% to 93.3% of the THg. A quantitative behavioural neurophysiological test battery, designed for use under standard conditions, in an area without electricity and for persons with minimal education was administered to all participants. The results of visual testing showed that although all participants had good near and far visual acuity, color discrimination capacity (Lanthony D-15 desaturated panel) decreased with increasing THg (F = 4.1; p = 0.05); near visual contrast sensitivity profiles (Vistech 6000) and peripheral visual field profiles (Goldman Perimetry with Targets I and V) were reduced for those with the highest levels of THg. For the women, manual dexterity (Santa Ana, Helsinki version) decreased with increasing THg (F = 16.7; p < 0.01); this was not the case for the men. Although the women showed a tendency towards reduced grip strength, muscular fatigue did not vary with THg for either sex. The findings of this study demonstrate that it is possible, using a sensitive test battery, to detect alterations in nervous system functions, consistent with knowledge on Hg toxicity, at levels below the currently recognized threshold of 50 micrograms/g THg. PMID:8784826

  13. Sulfate threshold target to control methylmercury levels in wetland ecosystems

    USGS Publications Warehouse

    Corrales, J.; Naja, G.M.; Dziuba, C.; Rivero, R.G.; Orem, W.

    2011-01-01

    Sulfate contamination has a significant environmental implication through the stimulation of toxic hydrogen sulfide and methylmercury (MeHg) production. High levels of MeHg are a serious problem in many wetland ecosystems worldwide. In the Florida Everglades, it has been demonstrated that increasing MeHg occurrence is due to a sulfate contamination problem. A promising strategy of lowering the MeHg occurrence is to reduce the amount of sulfate entering the ecosystem. High surface water sulfate concentrations in the Everglades are mainly due to discharges from the Everglades Agricultural Area (EAA) canals. Water and total sulfur mass balances indicated that total sulfur released by soil oxidation, Lake Okeechobee and agricultural application were the major sources contributing 49,169, 35,217 and 11,775mtonsyear-1, respectively. Total sulfur loads from groundwater, levees, and atmospheric deposition contributed to a lesser extent: 4055; 5858 and 4229mtonsyear-1, respectively. Total sulfur leaving the EAA into Water Conservation Areas (WCAs) through canal discharge was estimated at 116,360mtonsyear-1, and total sulfur removed by sugarcane harvest accounted for 23,182mtonsyear-1. Furthermore, a rise in the mineral content and pH of the EAA soil over time, suggested that the current rates of sulfur application would increase as the buffer capacity of the soil increases. Therefore, a site specific numeric criterion for sulfate of 1mgL-1 was recommended for the protection of the Everglades; above this level, mercury methylation is enhanced. In parallel, sulfide concentrations in the EAA exceeded the 2??gL-1 criterion for surface water already established by the U.S. Environmental Protection Agency (EPA). ?? 2011 Elsevier B.V.

  14. Methylmercury poisoning

    MedlinePlus

    ... mercury , a metal that is liquid at room temperature. A nickname for mercury is quicksilver. Most compounds ... methylmercury are present in many foods from the ocean, including deep-sea tuna. Fortunately, the levels are ...

  15. Implications of mercury concentrations in umbilical cord tissue in relation to maternal hair segments as biomarkers for prenatal exposure to methylmercury.

    PubMed

    Sakamoto, Mineshi; Murata, Katsuyuki; Domingo, José L; Yamamoto, Megumi; Oliveira, Ricardo B; Kawakami, Shoichi; Nakamura, Masaaki

    2016-08-01

    In this study, we investigated how mercury (Hg) concentrations in umbilical cord tissue are correlated with those in biomarkers for prenatal exposure to methylmercury (MeHg). Total Hg (T-Hg) concentrations were measured in 54 mother-child paired samples of maternal blood, umbilical cord tissue, cord blood, and maternal hair segments (1-cm incremental segments from the scalp) collected at parturition. MeHg concentrations were also measured in the cord tissue. Median T-Hg and MeHg concentrations in cord tissue on a dry-weight basis (d.w.) were 62.2ng/g and 56.7ng/g, respectively. Proportions of MeHg to T-Hg were approximately 95%. Both T-Hg and MeHg in cord tissue (d.w.) showed better correlations with T-Hg in cord blood than did T-Hg in cord tissue on a wet-weight basis (w.w.). Median T-Hg concentrations in maternal blood, cord blood, and maternal hair (0-1cm from the scalp) were 3.79ng/g, 7.26ng/g, and 1.35 μg/g, respectively. Median T-Hg concentration in cord blood was 1.92 times higher than that in maternal blood. T-Hg in cord tissue (d.w.) showed a strong correlation with that in cord blood (r=0.912, p<0.01). Among the hair segments, T-Hg in cord tissue (d.w.) showed the strongest correlation (r=0.854, p<0.01) with that in maternal hair at 0-1cm from the scalp, reflecting growth for approximately 1 month before parturition. Based on the present results, T-Hg and MeHg concentrations in cord tissue may be useful biomarkers for prenatal MeHg exposure of the fetus, especially reflecting the maternal MeHg body burden during late gestation. The conversion factors for T-Hg and MeHg concentrations in cord tissue (d.w.) to T-Hg concentrations in maternal hair (0-1cm from the scalp) were calculated to be 22.37 and 24.09, respectively. This information will be useful for evaluating maternal MeHg exposure levels in retrospective studies using preserved umbilical cord tissue. PMID:27156841

  16. Freshwater discharges drive high levels of methylmercury in Arctic marine biota.

    PubMed

    Schartup, Amina T; Balcom, Prentiss H; Soerensen, Anne L; Gosnell, Kathleen J; Calder, Ryan S D; Mason, Robert P; Sunderland, Elsie M

    2015-09-22

    Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25-200%, overwhelming climate-driven changes over the next decade. PMID:26351688

  17. Freshwater discharges drive high levels of methylmercury in Arctic marine biota

    PubMed Central

    Schartup, Amina T.; Balcom, Prentiss H.; Soerensen, Anne L.; Gosnell, Kathleen J.; Calder, Ryan S. D.; Mason, Robert P.; Sunderland, Elsie M.

    2015-01-01

    Elevated levels of neurotoxic methylmercury in Arctic food-webs pose health risks for indigenous populations that consume large quantities of marine mammals and fish. Estuaries provide critical hunting and fishing territory for these populations, and, until recently, benthic sediment was thought to be the main methylmercury source for coastal fish. New hydroelectric developments are being proposed in many northern ecosystems, and the ecological impacts of this industry relative to accelerating climate changes are poorly characterized. Here we evaluate the competing impacts of climate-driven changes in northern ecosystems and reservoir flooding on methylmercury production and bioaccumulation through a case study of a stratified sub-Arctic estuarine fjord in Labrador, Canada. Methylmercury bioaccumulation in zooplankton is higher than in midlatitude ecosystems. Direct measurements and modeling show that currently the largest methylmercury source is production in oxic surface seawater. Water-column methylation is highest in stratified surface waters near the river mouth because of the stimulating effects of terrestrial organic matter on methylating microbes. We attribute enhanced biomagnification in plankton to a thin layer of marine snow widely observed in stratified systems that concentrates microbial methylation and multiple trophic levels of zooplankton in a vertically restricted zone. Large freshwater inputs and the extensive Arctic Ocean continental shelf mean these processes are likely widespread and will be enhanced by future increases in water-column stratification, exacerbating high biological methylmercury concentrations. Soil flooding experiments indicate that near-term changes expected from reservoir creation will increase methylmercury inputs to the estuary by 25–200%, overwhelming climate-driven changes over the next decade. PMID:26351688

  18. Estimated intake levels for Finnish children of methylmercury from fish.

    PubMed

    Karjalainen, Anna K; Hallikainen, Anja; Hirvonen, Tero; Kiviranta, Hannu; Knip, Mikael; Kronberg-Kippilä, Carina; Leino, Olli; Simell, Olli; Sinkko, Harri; Tuomisto, Jouni T; Veijola, Riitta; Venäläinen, Eija-Riitta; Virtanen, Suvi M

    2013-04-01

    Methylmercury (MeHg) is a well-known neurotoxic agent, and consumption of contaminated fish is the principal environmental source of MeHg exposure in humans. Children are more susceptible to adverse effects than adults. No previous specific data exist for intake by Finnish children of methylmercury from fish. We estimated fish consumption and MeHg intakes from species most commonly consumed by Finnish children aged 1-6 years. The total mercury concentrations were determined in fish species consumed, and age-specific methylmercury intakes were derived. We also examined safety margins and the proportion of children exceeding the tolerable daily intakes set by international expert bodies. The daily intake of MeHg ranged from 0 to 0.33 μg/kg bw. The strictest reference value 0.1 μg/kg bw/day for MeHg, proposed by USEPA, was exceeded by 1-15% of the study population, and FAO/WHO JECFA provisional tolerable weekly intake of 1.6 μg/kg bw was exceeded by 1% of boys and 2.5% of girls aged 6 years. Intakes of 1-year old girls were higher than of boys, whereas for 3-year olds they were the opposite. The highest intakes were observed for 6-year-old boys and girls. There was great variation in the estimated MeHg intakes among Finnish children. PMID:22425939

  19. Methylmercury in fish: a review of residue levels, fish consumption and regulatory action in the United States

    SciTech Connect

    Tollefson, L.; Cordle, F.

    1986-09-01

    The dangers associated with the consumption of large amounts of methylmercury in fish are well recognized, and there is some evidence to suggest that methylmercury may be the cause of subtle neurological impairments when ingested at even low to moderate levels, particularly the prenatal and early childhood periods. This concern has prompted a continuing assessment of the risk of methylmercury toxicity among fish consumers in the US as well as other countries. The toxicokinetics of methylmercury in humans are reviewed and used to estimate body burdens associated with toxic effects. To determine seafood consumption patterns among the continental US population the Food and Drug Administration (FDA) has analyzed data from a diary study commissioned by the Tuna Research Foundation. Mercury residue levels in domestic fish sampled by the FDA were used to determine the level of exposure to methylmercury. Until evidence is presented that substantially lowers the known body burden of methylmercury which causes toxicity, calculations indicate that the current 1.0 ppm regulatory level provides adequate protection for the average fish consumer, for young children, and for a significant number of consumers exceeding the acceptable daily intake. However, additional studies are being carried out in a continuing process to ensure that safe levels of prenatal exposure to mercury residues in fish are maintained.

  20. Recognizing and Preventing Overexposure to Methylmercury from Fish and Seafood Consumption: Information for Physicians

    PubMed Central

    Silbernagel, Susan M.; Carpenter, David O.; Gilbert, Steven G.; Gochfeld, Michael; Groth, Edward; Hightower, Jane M.; Schiavone, Frederick M.

    2011-01-01

    Fish is a valuable source of nutrition, and many people would benefit from eating fish regularly. But some people eat a lot of fish, every day or several meals per week, and thus can run a significant risk of overexposure to methylmercury. Current advice regarding methylmercury from fish consumption is targeted to protect the developing brain and nervous system but adverse health effects are increasingly associated with adult chronic low-level methylmercury exposure. Manifestations of methylmercury poisoning are variable and may be difficult to detect unless one considers this specific diagnosis and does an appropriate test (blood or hair analysis). We provide information to physicians to recognize and prevent overexposure to methylmercury from fish and seafood consumption. Physicians are urged to ask patients if they eat fish: how often, how much, and what kinds. People who eat fish frequently (once a week or more often) and pregnant women are advised to choose low mercury fish. PMID:21785592

  1. Early Chronic Low-Level Methylmercury Poisoning in Monkeys Impairs Spatial Vision

    NASA Astrophysics Data System (ADS)

    Rice, Deborah C.; Gilbert, Steven G.

    1982-05-01

    Five monkeys were treated from birth with oral doses of mercury as methylmercury (50 micrograms per kilogram of body weight per day); concentrations in the blood peaked at 1.2 to 1.4 parts per million; and declined after weaning from infant formula to a steady level of 0.6 to 0.9 part per million. There were no overt signs of toxicity. When tested between 3 and 4 years of age under conditions of both high and low luminance, treated monkeys exhibited spatial vision that was impaired compared with that of control monkeys.

  2. Environmental influence on trace element levels in human hair

    SciTech Connect

    Limic, N.; Valkovic, V.

    1986-12-01

    Trace element content of human hair depends on many factors. It has been shown by a large number of investigators that environmental factors play an important role. Elements from air particulates, water, shampoo or other media get incorporated into the hair structure. Here a model is proposed in which different contributions to trace element levels in human hair are factorized and the environmental contribution to the radial and longitudinal concentration profiles can be calculated. With the proper understanding of environmental contamination, hair analysis has better chances of being used as a diagnostic tool.

  3. Trace-elements, methylmercury and metallothionein levels in Magellanic penguin (Spheniscus magellanicus) found stranded on the Southern Brazilian coast.

    PubMed

    Kehrig, Helena A; Hauser-Davis, Rachel A; Seixas, Tércia G; Fillmann, Gilberto

    2015-07-15

    Magellanic penguins have been reported as good biomonitors for several types of pollutants, including trace-elements. In this context, selenium (Se), total mercury, methylmercury, inorganic mercury (Hg(inorg)), cadmium (Cd) and lead (Pb), as well as metallothionein (MT) levels, were evaluated in the feathers, liver and kidney of juvenile Magellanic penguins found stranded along the coast of Southern Brazil. The highest concentrations of all trace-elements and methylmercury were found in internal organs. Concentrations of Cd and Se in feathers were extremely low in comparison with their concentrations in soft tissues. The results showed that both Se and MT are involved in the detoxification of trace-elements (Cd, Pb and Hg(inorg)) since statistically significant relationships were found in liver. Conversely, hepatic Se was shown to be the only detoxifying agent for methylmercury. PMID:25960272

  4. Serum Biotin Levels in Women Complaining of Hair Loss

    PubMed Central

    Trüeb, Ralph M

    2016-01-01

    Biotin is a coenzyme for carboxylase enzymes that assist various metabolic reactions involved in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis important for maintenance of healthy skin and hair. Due to its availability, affordability, and effective marketing for this purpose, biotin is a popular nutritional supplement for treatment of hair loss. However, there are little data on the frequency of biotin deficiency in patients complaining of hair loss and on the value of oral biotin for treatment of hair loss that is not due to an inborn error of biotin metabolism or deficiency. The aim of this study was to determine the frequency and significance of biotin deficiency in women complaining of hair loss. Biotin deficiency was found in 38% of women complaining of hair loss. Of those showing diffuse telogen effluvium in trichograms (24%), 35% had evidence of associated seborrheic-like dermatitis. About 11% of patients with biotin deficiency had a positive personal history for risk factors for biotin deficiency. The custom of treating women complaining of hair loss in an indiscriminate manner with oral biotin supplementation is to be rejected, unless biotin deficiency and its significance for the complaint of hair loss in an individual has been demonstrated on the basis of a careful patient history, clinical examination, determination of serum biotin levels, and exclusion of alternative factors responsible for hair loss. PMID:27601860

  5. Serum Biotin Levels in Women Complaining of Hair Loss.

    PubMed

    Trüeb, Ralph M

    2016-01-01

    Biotin is a coenzyme for carboxylase enzymes that assist various metabolic reactions involved in fatty acid synthesis, branched-chain amino acid catabolism, and gluconeogenesis important for maintenance of healthy skin and hair. Due to its availability, affordability, and effective marketing for this purpose, biotin is a popular nutritional supplement for treatment of hair loss. However, there are little data on the frequency of biotin deficiency in patients complaining of hair loss and on the value of oral biotin for treatment of hair loss that is not due to an inborn error of biotin metabolism or deficiency. The aim of this study was to determine the frequency and significance of biotin deficiency in women complaining of hair loss. Biotin deficiency was found in 38% of women complaining of hair loss. Of those showing diffuse telogen effluvium in trichograms (24%), 35% had evidence of associated seborrheic-like dermatitis. About 11% of patients with biotin deficiency had a positive personal history for risk factors for biotin deficiency. The custom of treating women complaining of hair loss in an indiscriminate manner with oral biotin supplementation is to be rejected, unless biotin deficiency and its significance for the complaint of hair loss in an individual has been demonstrated on the basis of a careful patient history, clinical examination, determination of serum biotin levels, and exclusion of alternative factors responsible for hair loss. PMID:27601860

  6. Chronic atrophic gastritis in association with hair mercury level.

    PubMed

    Xue, Zeyun; Xue, Huiping; Jiang, Jianlan; Lin, Bing; Zeng, Si; Huang, Xiaoyun; An, Jianfu

    2014-11-01

    The objective of this study was to explore hair mercury level in association with chronic atrophic gastritis, a precancerous stage of gastric cancer (GC), and thus provide a brand new angle of view on the timely intervention of precancerous stage of GC. We recruited 149 healthy volunteers as controls and 152 patients suffering from chronic gastritis as cases. The controls denied upper gastrointestinal discomforts, and the cases were diagnosed as chronic superficial gastritis (n=68) or chronic atrophic gastritis (n=84). We utilized Mercury Automated Analyzer (NIC MA-3000) to detect hair mercury level of both healthy controls and cases of chronic gastritis. The statistic of measurement data was expressed as mean ± standard deviation, which was analyzed using Levene variance equality test and t test. Pearson correlation analysis was employed to determine associated factors affecting hair mercury levels, and multiple stepwise regression analysis was performed to deduce regression equations. Statistical significance is considered if p value is less than 0.05. The overall hair mercury level was 0.908949 ± 0.8844490 ng/g [mean ± standard deviation (SD)] in gastritis cases and 0.460198 ± 0.2712187 ng/g (mean±SD) in healthy controls; the former level was significantly higher than the latter one (p=0.000<0.01). The hair mercury level in chronic atrophic gastritis subgroup was 1.155220 ± 0.9470246 ng/g (mean ± SD) and that in chronic superficial gastritis subgroup was 0.604732 ± 0.6942509 ng/g (mean ± SD); the former level was significantly higher than the latter level (p<0.01). The hair mercury level in chronic superficial gastritis cases was significantly higher than that in healthy controls (p<0.05). The hair mercury level in chronic atrophic gastritis cases was significantly higher than that in healthy controls (p<0.01). Stratified analysis indicated that the hair mercury level in healthy controls with eating seafood was significantly higher than that in healthy

  7. Methylmercury Exposure and Health Effects

    PubMed Central

    Hong, Young-Seoub; Kim, Yu-Mi

    2012-01-01

    Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea. PMID:23230465

  8. Methylmercury and Pregnancy

    MedlinePlus

    ... king crab, shrimp), or canned fish (including light tuna). Fish sticks and fast-food fish are likely ... with lower levels of methylmercury. Canned albacore (white) tuna and fresh tuna steaks typically have higher mercury ...

  9. Intraperitoneal injections as a possible means of generating varied levels of methylmercury in the eggs of birds in field studies

    USGS Publications Warehouse

    Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.

    2010-01-01

    The ideal study of the effects of methylmercury on the reproductive success of a species of bird would be one in which eggs contained mercury concentrations ranging from controls to very heavily contaminated, all at the same site. Such a study cannot be realized at a mercury contaminated area or under laboratory conditions, but could be achieved by introducing methylmercury into breeding females and allowing them to deposit mercury in their eggs. Female mallards (Anas platyrhynchos) were intraperitoneally injected with solutions of methylmercury chloride dissolved in corn oil, propylene glycol, dimethyl sulfoxide, mineral oil, Olestra, Crisco, lard, hard paraffin, and a combination of hard and soft paraffin. In some cases, egg laying was delayed, either due to the solvent itself (in the case of Olestra, Crisco, and lard) or to the highest concentration of methylmercury chloride (500 μg/g) in some of the solvents. Mercury in eggs ranged from a control level (< 0.1 μg/g) to approximately 14 μg/g on a wet weight basis, which more than covers the range of concentrations reported in wild bird eggs. Mercury concentrations in a series of eggs from the same female declined mostly due to excretion of mercury in prior eggs and not because of the length of time since the injection. Intraperitoneal injections hold promise in field studies where one would like to study the reproductive effects of a wide range of methylmercury levels in the eggs of a wild bird and under the natural conditions that exist in the field.

  10. Mercury levels in human hair and sex factors

    SciTech Connect

    Shimomura, S.; Kimura, A.; Nakagawa, H.; Takao, M.

    1980-06-01

    Evidence has been presented: (1) that the geometric mean is essential to the statistical analysis of the result of the amount of Hg in hair, and (2) that the individual Hg level in hair must be evaluated by the standard deviation of logarithmic values. The Hg level in hair obtained from 1324 inhabitants on Shikoku Island showed logarithmic-normal distribution curves, with higher values in males than in females. To verify such a sexual difference, hair samples were obtained from male and female children (N = 346), teenagers (N = 300), and adults (N = 354) living in an agricultural area of Tokushima Prefecture on the island. As the result, males were found to have more Hg than females in sexually mature teenagers and adults (P < 0.05 by F test) but not in younger children.

  11. Selenium and mercury levels in rat liver slices co-treated with diphenyl diselenide and methylmercury.

    PubMed

    Dalla Corte, Cristiane Lenz; Ramos, Angélica; Dos Santos, Clarissa Marques Moreira; Dressler, Valderi Luiz; da Rocha, João Batista Teixeira

    2016-06-01

    Organoseleno-compounds have been investigated for its beneficial effects against methylmercury toxicity. In this way, diphenyl diselenide (PhSe)2 was demonstrated to decrease Hg accumulation in mice, protect against MeHg-induced mitochondrial dysfunction, and protect against the overall toxicity of this metal. In the present study we aimed to investigate if co-treatment with (PhSe)2 and MeHg could decrease accumulation of Hg in liver slices of rats. Rat liver slices were co-treated with (PhSe)2 (0.5; 5 µM) and/or MeHg (25 µM) for 30 min at 37 °C and Se and Hg levels were measured by inductively coupled plasma mass spectrometry (ICP-MS) in the slices homogenate, P1 fraction, mitochondria and incubation medium. Co-treatment with (PhSe)2 and MeHg did not significantly alter Se levels in any of the samples when compared with compounds alone. In addition, co-treatment with (PhSe)2 and MeHg did not decrease Hg levels in any of the samples tested, although, co-incubation significantly increased Hg levels in homogenate. We suggest here that (PhSe)2 could exert its previously demonstrated protective effects not by reducing MeHg levels, but forming a complex with MeHg avoiding it to bind to critical molecules in cell. PMID:27138944

  12. Brain and tissue levels of mercury after chronic methylmercury exposure in the monkey

    SciTech Connect

    Rice, D.C.

    1989-01-01

    Estimated half-lives of mercury following methylmercury exposure in humans are 52-93 d for whole body and 49-164 d for blood. In its most recent 1980 review, the World Health Organization concluded that there was no evidence to suggest that brain half-life differed from whole-body half-life. In the present study, female monkeys (Macaca fascicularis) were dosed for at least 1.7 yr with 10, 25, or 50 micrograms/kg.d of mercury as methylmercuric chloride. Dosing was discontinued, and blood half-life was determined to be about 14 d. Approximately 230 d after cessation of dosing, monkeys were sacrificed and organ and regional brain total mercury levels determined. One monkey that died while still being dosed had brain mercury levels three times higher than levels in blood. Theoretical calculations were performed assuming steady-state brain:blood ratios of 3, 5, or 10. Brain mercury levels were at least three orders of magnitude higher than those predicted by assuming the half-life in brain to be the same as that in blood. Estimated half-lives in brain were between 56 (brain:blood ratio of 3) and 38 (brain:blood ratio of 10) d. In addition, there was a dose-dependent difference in half-lives for some brain regions. These data clearly indicate that brain half-life is considerably longer than blood half-life in the monkey under conditions of chronic dosing.

  13. Exposures of dental professionals to elemental mercury and methylmercury.

    PubMed

    Goodrich, Jaclyn M; Chou, Hwai-Nan; Gruninger, Stephen E; Franzblau, Alfred; Basu, Niladri

    2016-01-01

    Mercury (Hg) exposure, a worldwide public health concern, predominantly takes two forms--methylmercury from fish consumption and elemental Hg from dental amalgam restorations. We recruited 630 dental professionals from an American Dental Association meeting to assess Hg body burden and primary sources of exposure in a dually exposed population. Participants described occupational practices and fish consumption patterns via questionnaire. Hg levels in biomarkers of elemental Hg (urine) and methylmercury (hair and blood) were measured with a Direct Mercury Analyzer-80 and were higher than the general US population. Geometric means (95% CI) were 1.28 (1.19-1.37) μg/l in urine, 0.60 (0.54-0.67) μg/g in hair and 3.67 (3.38-3.98) μg/l in blood. In multivariable linear regression, personal amalgams predicted urine Hg levels along with total years in dentistry, amalgams handled, working hours and sex. Fish consumption patterns predicted hair and blood Hg levels, which were higher among Asians compared with Caucasians. Five species contributed the majority of the estimated Hg intake from fish--swordfish, fresh tuna, white canned tuna, whitefish and king mackerel. When studying populations with occupational exposure to Hg, it is important to assess environmental exposures to both elemental Hg and methylmercury as these constitute a large proportion of total exposure. PMID:26329138

  14. Cortisol levels in hair of East Greenland polar bears

    PubMed Central

    Bechshøft, TØ; Sonne, C; Dietz, R; Born, EW; Novak, MA; Henchey, E; Meyer, JS

    2010-01-01

    To demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (HPA) axis activity in polar bears (Ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3–19 years) and 10 male (6-19 years) East Greenland polar bears sampled 1994–2006. Hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. Samples were categorized according to contamination: Eight were clean (2 females, 6 males), 5 had been contaminated with bear blood (2 F, 3 M), and 4 with bear fat (3 F, 1 M). There was no significant difference in cortisol concentration between the three categories after external contamination was removed. However, contaminated hair samples should be cleaned before cortisol determination. Average hair cortisol concentration was 8.90 pg/mg (range: 5.5 to 16.4 pg/mg). There was no significant correlation between cortisol concentration and age (p = 0.81) or sampling year (p = 0.11). However, females had higher mean cortisol concentration than males (females mean: 11.0 pg/mg, males: 7.3 pg/mg; p = 0.01). The study showed that polar bear hair contains measurable amounts of cortisol and that cortisol in hair may be used in studies of long-term stress in polar bears. PMID:21144554

  15. Re-evaluation of the reference dose for methylmercury and assessment of current exposure levels

    SciTech Connect

    Stern, A.H. )

    1993-06-01

    Methylmercury (Me-Hg) is widely distributed through freshwater and saltwater food chains and human consumption of fish and shellfish has lead to widespread exposure. Both the US EPA Reference Dose (0.3 [mu]g/kg/day) and the FAO/WHO Permissible Tolerable Weekly Intake (3.3 [mu]g/kg/week) are currently based on the prevention of paraesthesia in adult and older children. However, Me-Hg exposure in utero is known to result in a range of developmental neurologic effects including clinical CNS symptoms and delayed onset of walking. Based on a critical review of development toxicity data from human and animal studies, it is concluded that current guidelines for the prevention of paraesthesia are not adequate to address developmental effects. A dose of 0.07 [mu]g/kg/day is suggested as the best estimate of a potential reference dose for developmental effects. Data on nationwide fish consumption rates and Me-Hg levels in fish/seafood weighted by proportion of the catch intended for human consumption are analyzed in a Monte Carlo simulation to derive a probability distribution of background Me-Hg exposure. While various uncertainties in the toxicologic and exposure data limit the precision with which health risk can be estimated, this analysis suggests that at current levels of Me-Hg exposure, a significant fraction of women of childbearing age have exposures above this suggested reference dose.

  16. PCBs levels and indicator congeners in children's and adolescents' hair.

    PubMed

    Liang, Baocui; Liu, Xinhui; Hou, Jing; Liang, Gang; Gong, Wenwen; Xu, Diandou; Zhang, Li

    2014-02-01

    Thirty polychlorinated biphenyl (PCB) congeners were determined in the hair samples collected from children (4-12) and adolescents (13-18) of Changchun city, Northeastern China. The mean concentrations of total PCBs and dioxin-like PCBs (dl-PCBs) in the adolescents' hair samples were 161.0 ng g(-1) and 61.7 ng g(-1), which were relatively higher than 43.7 ng g(-1) and 14.6 ng g(-1) in the children's ones. Considering gender difference, the mean concentrations in the girls' hair samples were approximately two times higher than those in the boys' ones for most PCB congeners. The pentachlorinated biphenyl was the dominant homologue. It was found that the levels of total PCBs and dl-PCBs were highly correlated with PCB 118 level in the children's hair samples, and with PCB 114 level in the adolescents' ones. The result demonstrated that the two PCB congeners could be applied as the indicators to evaluate the concentrations of total PCBs and dl-PCBs in children's and adolescents' hair, respectively. PMID:24212066

  17. Intervention study on cardiac autonomic nervous effects of methylmercury from seafood.

    PubMed

    Yaginuma-Sakurai, Kozue; Murata, Katsuyuki; Shimada, Miyuki; Nakai, Kunihiko; Kurokawa, Naoyuki; Kameo, Satomi; Satoh, Hiroshi

    2010-01-01

    To scrutinize whether the provisional tolerable weekly intake (PTWI, 3.4 microg/kg body weight/week) of methylmercury in Japan is safe for adults, we conducted an intervention study using heart rate variability (HRV) that has been considered to reflect cardiac events. Fifty-four healthy volunteers were recruited and divided into experimental and control groups. The experimental group was exposed to methylmercury at the PTWI level through consumption of bigeye tuna and swordfish for 14 weeks, and HRV parameters were compared between the two groups. In the experimental group, mean hair mercury levels, determined before and after the dietary methylmercury exposure and after 15-week wash-out period following the cessation of exposure, were 2.30, 8.76 and 4.90 microg/g, respectively. The sympathovagal balance index of HRV was significantly elevated after the exposure, and decreased to the baseline level at the end of this study. Still, such changes in HRV parameters were not found in the control group with a mean hair mercury level of around 2.1 microg/g. In conclusion, the PTWI does not appear to be safe for adult health, because methylmercury exposure from fish consumption induced a temporary sympathodominant state. Rather, long-term exposure to methylmercury may pose a potential risk for cardiac events involving sympathovagal imbalance among fish-consuming populations. PMID:19732823

  18. Cutaneous retinoic acid levels determine hair follicle development and downgrowth.

    PubMed

    Okano, Junko; Levy, Clara; Lichti, Ulrike; Sun, Hong-Wei; Yuspa, Stuart H; Sakai, Yasuo; Morasso, Maria I

    2012-11-16

    Retinoic acid (RA) is essential during embryogenesis and for tissue homeostasis, whereas excess RA is well known as a teratogen. In humans, excess RA is associated with hair loss. In the present study, we demonstrate that specific levels of RA, regulated by Cyp26b1, one of the RA-degrading enzymes, are required for hair follicle (hf) morphogenesis. Mice with embryonic ablation of Cyp26b1 (Cyp26b1(-/-)) have excessive endogenous RA, resulting in arrest of hf growth at the hair germ stage. The altered hf development is rescued by grafting the mutant skin on immunodeficient mice. Our results show that normalization of RA levels is associated with reinitiation of hf development. Conditional deficiency of Cyp26b1 in the dermis (En1Cre;Cyp26b1f/-) results in decreased hair follicle density and specific effect on hair type, indicating that RA levels also influence regulators of hair bending. Our results support the model of RA-dependent dermal signals regulating hf downgrowth and bending. To elucidate target gene pathways of RA, we performed microarray and RNA-Seq profiling of genes differentially expressed in Cyp26b1(-/-) skin and En1Cre;Cyp26b1f/- tissues. We show specific effects on the Wnt-catenin pathway and on members of the Runx, Fox, and Sox transcription factor families, indicating that RA modulates pathways and factors implicated in hf downgrowth and bending. Our results establish that proper RA distribution is essential for morphogenesis, development, and differentiation of hfs. PMID:23007396

  19. Cutaneous Retinoic Acid Levels Determine Hair Follicle Development and Downgrowth*

    PubMed Central

    Okano, Junko; Levy, Clara; Lichti, Ulrike; Sun, Hong-Wei; Yuspa, Stuart H.; Sakai, Yasuo; Morasso, Maria I.

    2012-01-01

    Retinoic acid (RA) is essential during embryogenesis and for tissue homeostasis, whereas excess RA is well known as a teratogen. In humans, excess RA is associated with hair loss. In the present study, we demonstrate that specific levels of RA, regulated by Cyp26b1, one of the RA-degrading enzymes, are required for hair follicle (hf) morphogenesis. Mice with embryonic ablation of Cyp26b1 (Cyp26b1−/−) have excessive endogenous RA, resulting in arrest of hf growth at the hair germ stage. The altered hf development is rescued by grafting the mutant skin on immunodeficient mice. Our results show that normalization of RA levels is associated with reinitiation of hf development. Conditional deficiency of Cyp26b1 in the dermis (En1Cre;Cyp26b1f/−) results in decreased hair follicle density and specific effect on hair type, indicating that RA levels also influence regulators of hair bending. Our results support the model of RA-dependent dermal signals regulating hf downgrowth and bending. To elucidate target gene pathways of RA, we performed microarray and RNA-Seq profiling of genes differentially expressed in Cyp26b1−/− skin and En1Cre;Cyp26b1f/− tissues. We show specific effects on the Wnt-catenin pathway and on members of the Runx, Fox, and Sox transcription factor families, indicating that RA modulates pathways and factors implicated in hf downgrowth and bending. Our results establish that proper RA distribution is essential for morphogenesis, development, and differentiation of hfs. PMID:23007396

  20. Moose milk and hair element levels and relationships.

    PubMed

    Franzmann, A W; Flynn, A; Arneson, P D

    1976-04-01

    Milk was collected from 21 Alaskan moose (Alces alces gigas) at the Kenai Moose Research Center (MRC), Soldotna, Alaska nad analyzed by atomic absorption spectroscopy for Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se and Zn. Hair samples were collected from 100 moose at the MRC to correspond with the lactation period and serve as a metabolic indicator of mineral elements stored in tissue. Published analyses of bovine milk were compared to moose milk; Al, Fe, Se and Zn were higher in moose milk by factors of 1.6 to 290. Elements potentially influenced by nutrition and those determined genetically were also considered. Elements in moose milk and hair values were compared, since mineral element levels in hair potentially reflect the availability and intake of these elements. Calcium and Mg were the only values in hair lower than the values in milk (factors of 4.2 and 1.5 respectively). Moose, as well as domestic cattle, apparently are subjected to lactation stress by the genetically determined levels of Ca and Mg in milk. PMID:933310

  1. Evidence on the Human Health Effects of Low-Level Methylmercury Exposure

    PubMed Central

    Choi, Anna L.; Oken, Emily; Horvat, Milena; Schoeny, Rita; Kamai, Elizabeth; Cowell, Whitney; Grandjean, Philippe; Korrick, Susan

    2012-01-01

    Background: Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by bene-ficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. Objectives: We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. Data sources and extraction: We reviewed the published literature for original human epidemio-logic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). Data synthesis: Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. Conclusions: Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts

  2. Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function

    SciTech Connect

    Ohno, Tomoko; Sakamoto, Mineshi; Kurosawa, Tomoko; Dakeishi, Miwako; Iwata, Toyoto; Murata, Katsuyuki . E-mail: winestem@med.akita-u.ac.jp

    2007-02-15

    To investigate the relations among total mercury levels in hair, toenail, and urine, together with potential effects of methylmercury intake on renal tubular function, we determined their levels, and urinary N-acetyl-{beta}-d-glucosaminidase activity (NAG) and {alpha}{sub 1}-microglobulin (AMG) in 59 women free from occupational exposures, and estimated daily mercury intakes from fish and other seafood using a food frequency questionnaire. Mercury levels (mean+/-SD) in the women were 1.51+/-0.91{mu}g/g in hair, 0.59+/-0.32{mu}g/g in toenail, and 0.86+/-0.66{mu}g/g creatinine in urine; and, there were positive correlations among them (P<0.001). The daily mercury intake of 9.15+/-7.84{mu}g/day was significantly correlated with total mercury levels in hair, toenail, and urine (r=0.551, 0.537, and 0.604, P<0.001). Among the women, the NAG and AMG were positively correlated with both the daily mercury intake and mercury levels in hair, toenail, and urine (P<0.01); and, these relations were almost similar when using multiple regression analysis to adjust for possible confounders such as urinary cadmium (0.47+/-0.28{mu}g/g creatinine) and smoking status. In conclusion, mercury resulting from fish consumption can explain total mercury levels in hair, toenail, and urine to some degree (about 30%), partly through the degradation into the inorganic form, and it may confound the renal tubular effect of other nephrotoxic agents. Also, the following equation may be applicable to the population neither with dental amalgam fillings nor with occupational exposures: [hair mercury ({mu}g/g)]=2.44x[toenail mercury ({mu}g/g)].

  3. Enhanced reproduction in mallards fed a low level of methylmercury: An apparent case of hormesis

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.

    2010-01-01

    Breeding pairs of mallards (Anas platyrhynchos) were fed a control diet or a diet containing 0.5 mg/g mercury (Hg) in the form of methylmercury chloride. There were no effects of Hg on adult weights and no overt signs of Hg poisoning in adults. The Hg-containing diet had no effect on fertility of eggs, but hatching success of eggs was significantly higher for females fed 0.5 ??g/g Hg (71.8%) than for controls (57.5%). Survival of ducklings through 6 d of age was the same (97.8%) for controls and mallards fed 0.5 ??g/g mercury. However, the mean number of ducklings produced per female was significantly higher for the pairs fed 0.5 ??g/g Hg (21.4) than for controls (16.8). Although mercury in the parents' diet had no effect on mean duckling weights at hatching, ducklings from parents fed 0.5 mg/g Hg weighed significantly more (mean = 87.2 g) at 6 d of age than did control ducklings (81.0 g). The mean concentration of Hg in eggs laid by parents fed 0.5 ??g/g mercury was 0.81 ??g/g on a wet-weight basis. At this time, one cannot rule out the possibility that low concentrations of Hg in eggs may be beneficial, and this possibility should be considered when setting regulatory thresholds for methylmercury. ?? 2009 SETAC.

  4. Fish consumption patterns and hair mercury levels in children and their mothers in 17 EU countries.

    PubMed

    Castaño, Argelia; Cutanda, Francisco; Esteban, Marta; Pärt, Peter; Navarro, Carmen; Gómez, Silvia; Rosado, Montserrat; López, Ana; López, Estrella; Exley, Karen; Schindler, Birgit K; Govarts, Eva; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Fiddicke, Ulrike; Koch, Holger; Angerer, Jürgen; Den Hond, Elly; Schoeters, Greet; Sepai, Ovnair; Horvat, Milena; Knudsen, Lisbeth E; Aerts, Dominique; Joas, Anke; Biot, Pierre; Joas, Reinhard; Jiménez-Guerrero, José A; Diaz, Gema; Pirard, Catherine; Katsonouri, Andromachi; Cerna, Milena; Gutleb, Arno C; Ligocka, Danuta; Reis, Fátima M; Berglund, Marika; Lupsa, Ioana-Rodica; Halzlová, Katarína; Charlier, Corinne; Cullen, Elizabeth; Hadjipanayis, Adamos; Krsková, Andrea; Jensen, Janne F; Nielsen, Jeanette K; Schwedler, Gerda; Wilhelm, Michael; Rudnai, Peter; Középesy, Szilvia; Davidson, Fred; Fischer, Mark E; Janasik, Beata; Namorado, Sónia; Gurzau, Anca E; Jajcaj, Michal; Mazej, Darja; Tratnik, Janja Snoj; Larsson, Kristin; Lehmann, Andrea; Crettaz, Pierre; Lavranos, Giagkos; Posada, Manuel

    2015-08-01

    The toxicity of methylmercury (MeHg) in humans is well established and the main source of exposure is via the consumption of large marine fish and mammals. Of particular concern are the potential neurodevelopmental effects of early life exposure to low-levels of MeHg. Therefore, it is important that pregnant women, children and women of childbearing age are, as far as possible, protected from MeHg exposure. Within the European project DEMOCOPHES, we have analyzed mercury (Hg) in hair in 1799 mother-child pairs from 17 European countries using a strictly harmonized protocol for mercury analysis. Parallel, harmonized questionnaires on dietary habits provided information on consumption patterns of fish and marine products. After hierarchical cluster analysis of consumption habits of the mother-child pairs, the DEMOCOPHES cohort can be classified into two branches of approximately similar size: one with high fish consumption (H) and another with low consumption (L). All countries have representatives in both branches, but Belgium, Denmark, Spain, Portugal and Sweden have twice as many or more mother-child pairs in H than in L. For Switzerland, Czech Republic, Hungary, Poland, Romania, Slovenia and Slovakia the situation is the opposite, with more representatives in L than H. There is a strong correlation (r=0.72) in hair mercury concentration between the mother and child in the same family, which indicates that they have a similar exposure situation. The clustering of mother-child pairs on basis of their fish consumption revealed some interesting patterns. One is that for the same sea fish consumption, other food items of marine origin, like seafood products or shellfish, contribute significantly to the mercury levels in hair. We conclude that additional studies are needed to assess and quantify exposure to mercury from seafood products, in particular. The cluster analysis also showed that 95% of mothers who consume once per week fish only, and no other marine products

  5. Elevated hair cortisol levels in chronically stressed dementia caregivers.

    PubMed

    Stalder, Tobias; Tietze, Antje; Steudte, Susann; Alexander, Nina; Dettenborn, Lucia; Kirschbaum, Clemens

    2014-09-01

    Hair cortisol concentrations (HCC) are assumed to reflect integrated long-term cortisol levels and have been proposed as a promising endocrine marker of chronic psychological stress. The current study examined HCC in relation to caregiving burden, a well-established naturalistic model of chronic stress in humans. HCC and relevant psychosocial data were examined in 20 caregivers of relatives with dementia and 20 non-caregiver controls matched for age and sex. Results revealed elevated HCC in dementia caregivers compared to non-caregiver controls (F(1,38)=4.4, p=.04, ηp2=.10). Further, within caregivers, a trend for a positive association of HCC with self-reported caregiving burden (r=.43, p=.058) and a positive association with depressiveness (r=.48, p=.045) were observed. No other associations between HCC and subjective measures were seen. These findings concur with the notion that HCC sensitively capture endocrine aberrations in stress-exposed groups. PMID:25001953

  6. Assessing sources of human methylmercury exposure using stable mercury isotopes.

    PubMed

    Li, Miling; Sherman, Laura S; Blum, Joel D; Grandjean, Philippe; Mikkelsen, Bjarni; Weihe, Pál; Sunderland, Elsie M; Shine, James P

    2014-01-01

    Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in δ(202)Hg values between pilot whale muscle tissue and Faroese whalers' hair but no mass-independent fractionation. We found a similar offset in δ(202)Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual MeHg exposure sources and confirmed that both Δ(199)Hg and δ(202)Hg values in human hair can help identify dietary MeHg sources. Variability in isotopic signatures among coastal fish consumers in the Gulf of Mexico likely reflects both differences in environmental sources of MeHg to coastal fish and uncertainty in dietary recall data. Additional data are needed to fully refine this approach for individuals with complex seafood consumption patterns. PMID:24967674

  7. Biomonitoring of Lead, Cadmium, Total Mercury, and Methylmercury Levels in Maternal Blood and in Umbilical Cord Blood at Birth in South Korea

    PubMed Central

    Kim, Yu-Mi; Chung, Jin-Young; An, Hyun Sook; Park, Sung Yong; Kim, Byoung-Gwon; Bae, Jong Woon; Han, Myoungseok; Cho, Yeon Jean; Hong, Young-Seoub

    2015-01-01

    With rising concerns of heavy metal exposure in pregnancy and early childhood, this study was conducted to assess the relationship between the lead, cadmium, mercury, and methylmercury blood levels in pregnancy and neonatal period. The study population included 104 mothers and their children pairs who completed both baseline maternal blood sampling at the second trimester and umbilical cord blood sampling at birth. The geometric mean maternal blood levels of lead, cadmium, total mercury, and methylmercury at the second trimester were 1.02 ± 1.39 µg/dL, 0.61 ± 1.51 µg/L, 2.97 ± 1.45 µg/L, and 2.39 ± 1.45 µg/L, respectively, and in the newborns, these levels at birth were 0.71 ± 1.42 µg/dL, 0.01 ± 5.31 µg/L, 4.44 ± 1.49 µg/L, and 3.67 ± 1.51 µg/L, respectively. The mean ratios of lead, cadmium, total mercury, and methylmercury levels in the newborns to those in the mothers were 0.72, 0.04, 1.76, and 1.81, respectively. The levels of most heavy metals in pregnant women and infants were higher in this study than in studies from industrialized western countries. The placenta appears to protect fetuses from cadmium; however, total mercury and methylmercury were able to cross the placenta and accumulate in fetuses. PMID:26516876

  8. Serum drug level-related sodium valproate-induced hair loss

    PubMed Central

    Ramakrishnappa, Suresh K.; Belhekar, Mahesh N.

    2013-01-01

    Sodium valproate is a well-established treatment in epilepsy and mood disorders. Its utility is compromised by its adverse effects such as tremor, weight gain, hair loss, and liver dysfunction. Hair loss may occur when drug is used in higher dose. Drug-induced hair loss is diffused and non-scarring, which is reversible upon withdrawal. But there are no case reports showing relation between serum levels of valproate and occurrence of hair loss. So we took interest in reporting this case report. PMID:23716898

  9. Hair as a meaningful measure of baseline cortisol levels over time in dogs.

    PubMed

    Bryan, Heather M; Adams, Amanda G; Invik, Rosemary M; Wynne-Edwards, Katherine E; Smits, Judit E G

    2013-03-01

    Cortisol measurements of hair are becoming a valuable tool in monitoring chronic stress. To further validate this approach in domestic dogs, we compared the variability of cortisol immunoreactivity in hair with that in saliva and feces of dogs housed under constant social and physical conditions. Fecal (n = 268), and hair (n = 21) samples were collected over 3 mo from 7 dogs housed in a kennel and kept for training veterinary students in minimally invasive procedures. Salivary samples (n = 181) were collected 3 times daily twice weekly during the last month of the study. Hair and salivary samples were analyzed by enzyme immunoassay and feces by radioimmunoassay. HPLC coupled with tandem mass spectrometry was used to confirm the presence of cortisol in 3 hair samples. Variability of cortisol was compared across sample types by using repeated-measures ANOVA followed by paired t tests. Within dogs, cortisol immunoreactivity was less variable in hair than in saliva or feces. Averaged over time, the variability of fecal samples approached that of hair when feces were collected at least 4 times monthly. As predicted, the stable social and environmental condition of the dogs maintained repeatability over time and supported the hypothesis that data from hair samples reflect baseline cortisol levels. These findings indicate that determining cortisol immunoreactivity in hair is a more practical approach than is using samples of saliva or feces in monitoring the effects of long-term stressors such as social or physical environments and disease progression. PMID:23562104

  10. Hair as a Meaningful Measure of Baseline Cortisol Levels over Time in Dogs

    PubMed Central

    Bryan, Heather M; Adams, Amanda G; Invik, Rosemary M; Wynne-Edwards, Katherine E; Smits, Judit EG

    2013-01-01

    Cortisol measurements of hair are becoming a valuable tool in monitoring chronic stress. To further validate this approach in domestic dogs, we compared the variability of cortisol immunoreactivity in hair with that in saliva and feces of dogs housed under constant social and physical conditions. Fecal (n = 268), and hair (n = 21) samples were collected over 3 mo from 7 dogs housed in a kennel and kept for training veterinary students in minimally invasive procedures. Salivary samples (n = 181) were collected 3 times daily twice weekly during the last month of the study. Hair and salivary samples were analyzed by enzyme immunoassay and feces by radioimmunoassay. HPLC coupled with tandem mass spectrometry was used to confirm the presence of cortisol in 3 hair samples. Variability of cortisol was compared across sample types by using repeated-measures ANOVA followed by paired t tests. Within dogs, cortisol immunoreactivity was less variable in hair than in saliva or feces. Averaged over time, the variability of fecal samples approached that of hair when feces were collected at least 4 times monthly. As predicted, the stable social and environmental condition of the dogs maintained repeatability over time and supported the hypothesis that data from hair samples reflect baseline cortisol levels. These findings indicate that determining cortisol immunoreactivity in hair is a more practical approach than is using samples of saliva or feces in monitoring the effects of long-term stressors such as social or physical environments and disease progression. PMID:23562104

  11. Methylmercury in water samples at the pg/L level by online preconcentration liquid chromatography cold vapor-atomic fluorescence spectrometry

    NASA Astrophysics Data System (ADS)

    Brombach, Christoph-Cornelius; Chen, Bin; Corns, Warren T.; Feldmann, Jörg; Krupp, Eva M.

    2015-03-01

    Ultra-traces of methylmercury at the sub-ppt level can be magnified in the foodweb and is of concern. In environmental monitoring a routine robust analytical method is needed to determine methylmercury in water. The development of an analytical method for ultra-trace speciation analysis of methylmercury (MeHg) in water samples is described. The approach is based on HPLC-CV-AFS with on-line preconcentration of water samples up to 200 mL, resulting in a detection limit of 40 pg/L (ppq) for MeHg, expressed as Hg. The unit consists of an optimized preconcentration column filled with a sulfur-based sorption material, on which mercury species are preconcentrated and subsequently eluted, separated and detected via HPLC-CV-AFS (high performance liquid chromatography-cold vapor atomic fluorescence spectrometry). During the method development a type of adsorbate material, the pH dependence, the sample load rate and the carry-over were investigated using breakthrough experiments. The method shows broad pH stability in the range of pH 0 to 7, without the need for buffer addition and shows limited matrix effects so that MeHg is quantitatively recovered from sewage, river and seawater directly in the acidified samples without sample preparation.

  12. Human hair mercury levels in the Wanshan mercury mining area, Guizhou Province, China.

    PubMed

    Li, Ping; Feng, Xinbin; Qiu, Guangle; Shang, Lihai; Li, Guanghui

    2009-12-01

    The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province, Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 μg/g and 1.9 ± 0.9 μg/g for T-Hg and Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 μg/g and 1.2 ± 0.5 μg/g for T-Hg and Me-Hg, respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents, respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the Wanshan Hg mining area. PMID:19160059

  13. New Evidence on Variations of Human Body Burden of Methylmercury from Fish Consumption

    PubMed Central

    Canuel, René; de Grosbois, Sylvie Boucher; Atikessé, Laura; Lucotte, Marc; Arp, Paul; Ritchie, Charles; Mergler, Donna; Chan, Hing Man; Amyot, Marc; Anderson, Robin

    2006-01-01

    Epidemiologic studies commonly use mercury (Hg) level in hair as a valid proxy to estimate human exposure to methylmercury (MeHg) through fish consumption. This study presents the results yielded by a complete data set on fish consumption habits, Hg levels in edible fish resources, and corresponding Hg accumulation in hair, gathered in three distinct communities of eastern Canada. For one of these communities, the average hair Hg concentration was 14 times less than the expected value based on calculated daily oral exposure and current knowledge of MeHg metabolism. This finding could be explained by differences in specific genetic characteristics and/or interactive effects of other dietary components. PMID:16451872

  14. Methylmercury Poisoning in Iraq

    ERIC Educational Resources Information Center

    Bakir, F.; And Others

    1973-01-01

    Discusses incidence of methylmercury poisoning throughout the world with increasing industrial and agricultural use of mercury compounds. Describes recent epidemic in Iraq resulting from use of wheat treated with methylmercurial fungicide. New data are presented on the toxicity of methylmercury and its metabolic fate in the human body. (JR)

  15. Serum and hair zinc levels in breast cancer: a meta-analysis

    PubMed Central

    Wu, Xiujuan; Tang, Jing; Xie, Mingjun

    2015-01-01

    Many studies have investigated the association between serum/hair zinc levels and breast cancer, but the results were inconsistent. To compare the serum and hair zinc levels in women with breast cancer and controls, we conducted a systematic literature search of PubMed, Web of Science, Cochrane Library and Embase to identify relevant studies with publication dates up through November 2014. Based on a random effects model, summary standard mean differences (SMDs) and the corresponding 95% confidence intervals (CIs) were used to compare the serum and hair zinc levels in women with breast cancer and controls. Fourteen studies that investigated serum zinc levels and seven studies that assessed hair zinc levels were included. Our study observed no difference in serum zinc levels between breast cancer cases and controls (SMD (95%CI): −0.65[−1.42,0.13]). However, we determined that hair zinc levels were lower in women with breast cancer compared with those of controls (SMD (95%CI): −1.99[−3.46, −0.52]). In conclusion, this study was the first to provide evidence that hair zinc levels in female breast cancer patients are lower than in controls; however, there was no significant difference in serum zinc levels between female breast cancer patients and controls. PMID:26179508

  16. Elevated iron levels in hair from steel mill workers in Karachi, Pakistan

    SciTech Connect

    Jamall, I.S.; Jaffer, R.A.

    1987-10-01

    Over the last two decades, much interest has been focused on the use of trace metals in human hair to diagnose nutritional deficiencies of these metals or toxicities of metals such as lead or organic mercury. Although the diagnostic value of zinc (Zn), copper (Cu), lead and mercury levels in human hair have been well established, little information is available on the significance of iron (Fe) levels in hair to diagnose nutritional deficiency or toxicity of this metal. The present study was conducted to determine if occupational exposure in the steel industry resulted in alterations i the levels of Fe, Zn, and Cu in hair and could thus serve as a simple tool for monitoring exposure to potentially hazardous levels of these metals.

  17. Influence of Reservoir Water Level Fluctuations on Sediment Methylmercury Concentrations Downstream of the Historical Black Butte Mercury Mine, OR

    EPA Science Inventory

    Mercury (Hg) is a pollutant of global concern due to its ability to accumulate as methylmercury (MeHg) in biota. Mercury is methylated by anaerobic microorganisms such as sulfate reducing bacteria (SRB) in water and sediment. Throughout North America, reservoirs tend to have e...

  18. Low level Methylmercury enhances CNTF-evoked STAT3 signaling and glial differentiation in cultured cortical progenitor cells

    PubMed Central

    Jebbett, Nathan J.; Hamilton, Joshua W.; Rand, Matthew D.; Eckenstein, Felix

    2013-01-01

    Although many previous investigations have studied how mercury compounds cause cell death, sub-cytotoxic levels may affect mechanisms essential for the proper development of the nervous system. The present study investigates whether low doses of methylmercury (MeHg) and mercury chloride (HgCl2) can modulate the activity of JAK/STAT signaling, a pathway that promotes gliogenesis. We report that sub-cytotoxic doses of MeHg enhance ciliary neurotrophic factor (CNTF) evoked STAT3 phosphorylation in human SH-SY5Y neuroblastoma and mouse cortical neural progenitor cells (NPCs). This effect is specific for MeHg, since HgCl2 fails to enhance JAK/STAT signaling. Exposing NPCs to these low doses of MeHg (30-300 nM) enhances CNTF-induced expression of STAT3-target genes such as glial fibrillary acidic protein (GFAP) and suppressors of cytokine signaling 3 (SOCS3), and increases the proportion of cells expressing GFAP following two days of differentiation. Higher, near-cytotoxic concentrations of MeHg and HgCl2 inhibit STAT3 phosphorylation and lead to increased production of superoxide. Lower concentrations of MeHg effective in enhancing JAK/STAT signaling (30 nM) do not result in a detectable increase in superoxide nor increased expression of the oxidant-responsive genes, heme oxygenase 1, heat shock protein A5 and sirtuin 1. These findings suggest that low concentrations of MeHg inappropriately enhance STAT3 phosphorylation and glial differentiation, and that the mechanism causing this enhancement is distinct from the reactive oxygen species -associated cell death observed at higher concentrations of MeHg and HgCl2. PMID:23845766

  19. High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic.

    PubMed

    MacMillan, Gwyneth A; Girard, Catherine; Chételat, John; Laurion, Isabelle; Amyot, Marc

    2015-07-01

    Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (<0.1 ng L(-1)). High MeHg was measured in the bottom waters of Subarctic thaw ponds near Kuujjuarapik (0.1-3.1 ng L(-1)). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems. PMID:26030209

  20. Cortisol levels in hair reflect behavioural reactivity of dogs to acoustic stimuli.

    PubMed

    Siniscalchi, M; McFarlane, J R; Kauter, K G; Quaranta, A; Rogers, L J

    2013-02-01

    Cortisol levels in hair samples were examined in fourteen domestic dogs and related to the dogs' responses to different acoustic stimuli. Stimuli were playbacks of species-typical vocalizations recorded during three different situations ("disturbance", "isolation" and "play" barks) and the sounds of a thunderstorm. Hair samples were collected at 9:00 h and 17:00 h two weeks after the behavioural tests. Results showed that behavioural reactivity to playback of the various stimuli correlates with cortisol levels in hair samples collected at 9:00 h, and the same was the case for the separate measures of behaviour (i.e. hiding, running away, seeking attention from the tester, panting and lowering of the body posture). Hence, levels of cortisol in hair appear to reflect the dog's chronic state of emotional reactivity, or temperament. PMID:22449333

  1. Before You're Pregnant - Methylmercury

    MedlinePlus

    ... nutrients and it's low in fat. However, some fish contain high levels of methylmercury, which can harm ... a metal that can be found in certain fish, including swordfish , tilefish , king mackerel , and shark . Eating ...

  2. Fish consumption and hair mercury levels in women of childbearing age, Martin County, Florida.

    PubMed

    Nair, Anil; Jordan, Melissa; Watkins, Sharon; Washam, Robert; DuClos, Chris; Jones, Serena; Palcic, Jason; Pawlowicz, Marek; Blackmore, Carina

    2014-12-01

    The health effects of mercury in humans are mostly on the developing nervous system. Pregnant women and women who are breastfeeding must be targeted in order to decrease mercury exposure to the populations at highest risk-infants, unborn fetuses, and young children. This purpose of this study is to understand the demographics of fish-consumption patterns among women of childbearing age (including pregnant women) in Martin County, Florida, and to analyze the associations of mercury levels in participants' hair with socio-demographic variables in order to better design prevention messages and campaigns. Mercury concentrations in hair samples of 408 women ages 18-49 were assessed. Data on demographic factors, pregnancy status, fish consumption, and awareness of fish advisories were collected during personal interviews. Data were analyzed using descriptive statistics and multivariate logistic regression. The geometric and arithmetic means of hair mercury concentration were 0.371 and 0.676 µg/g of hair. One-fourth of the respondents had a concentration ≥1 µg/g of hair. Consuming a higher number of fish meals per month, consumption of commercially purchased or locally caught fish higher in mercury, White race and income ≥$75,000 were positively associated with the likelihood of having higher hair mercury levels. This study confirms the existence of a higher overall mean hair mercury level and a higher percentage of women with ≥1 µg/g hair mercury level than those reported at the national level and in other regional studies. This suggests the need for region-specific fish consumption advisories to minimize mercury exposure in humans. PMID:24807406

  3. Low-Level Laser (Light) Therapy (LLLT) for Treatment of Hair Loss

    PubMed Central

    Avci, Pinar; Gupta, Gaurav K.; Clark, Jason; Wikonkal, Norbert; Hamblin, Michael R.

    2013-01-01

    Objective Alopecia is a common disorder affecting more than half of the population worldwide. Androgenetic alopecia, the most common type, affects 50% of males over the age of 40 and 75% of females over 65. Only two drugs have been approved so far (minoxidil and finasteride) and hair transplant is the other treatment alternative. This review surveys the evidence for low-level laser therapy (LLLT) applied to the scalp as a treatment for hair loss and discusses possible mechanisms of actions. Methods and Materials Searches of PubMed and Google Scholar were carried out using keywords alopecia, hair loss, LLLT, photobiomodulation. Results Studies have shown that LLLT stimulated hair growth in mice subjected to chemotherapy-induced alopecia and also in alopecia areata. Controlled clinical trials demonstrated that LLLT stimulated hair growth in both men and women. Among various mechanisms, the main mechanism is hypothesized to be stimulation of epidermal stem cells in the hair follicle bulge and shifting the follicles into anagen phase. Conclusion LLLT for hair growth in both men and women appears to be both safe and effective. The optimum wavelength, coherence and dosimetric parameters remain to be determined. PMID:23970445

  4. Hair mercury levels in pregnant women in Mahshahr, Iran: fish consumption as a determinant of exposure.

    PubMed

    Salehi, Zohreh; Esmaili-Sari, Abbas

    2010-09-15

    MeHg is a well-documented neurotoxicant even at low levels of exposure. Developing brain, in particular, is vulnerable to that. Through bioaccumulating to differing degrees in various fish species, it can have serious adverse effects on the development and functioning of the human central nervous system, especially during prenatal exposure. Therefore, the purpose of this study was to investigate mercury concentration in hair samples of pregnant women living in Mahshahr located in Khuzestan province, Iran. It assessed the association between fish consumption and specific characteristics that can influence exposure. From April to June 2008, 149 pregnant women were invited to participate in this study. An interview administered questionnaire was used to collect information about age, body weight, height, fish (fresh, canned and shrimp) consumption, pregnancy stage, residence duration, education level, family income and number of dental amalgam fillings. The obtained results showed that the geometric mean and range for hair total Hg concentration was 3.52 microg/g (0.44-53.56 microg/g). About 5.4% of mothers had hair total Hg levels in excess of 10 microg/g. Maternal hair mercury level was less than threshold level of WHO (5 microg/g). As expected, there was a clear increase in hair Hg with reported fresh marine fish consumption (p=0.04). The highest mean for hair mercury level in a group who consumed fish several times per week, was 4.93 microg/g. Moreover, a significant effect of age and residential time on Hg concentration in the hair of the women was found. Pregnant women in Mahshahr consumed large amounts of fish; consequently, most of their offspring were prenatally exposed to moderately high levels of mercury. The results found suggest that pregnant women should decrease their fish consumption. PMID:20655095

  5. Hormone levels in neonatal hair reflect prior maternal stress exposure during pregnancy.

    PubMed

    Kapoor, Amita; Lubach, Gabriele R; Ziegler, Toni E; Coe, Christopher L

    2016-04-01

    Hormones present in hair provide summative information about endocrine activity while the hair was growing. Therefore, it can be collected from an infant after birth and still provide retrospective information about hormone exposure during prenatal development. We employed this approach to determine whether a delimited period of maternal stress during pregnancy affected the concentrations of glucocorticoids and gonadal hormones in the hair of neonatal rhesus monkeys. Hair from 22 infant monkeys exposed to 5 weeks of gestational disturbance was compared to specimens from 13 infants from undisturbed control pregnancies. Using an LC/MS/MS based technique, which permitted seven steroid hormones to be quantified simultaneously, we found 2 hormones were significantly different in infants from disturbed pregnancies. Cortisol and testosterone levels were lower in the hair of both male and female neonates. Maternal hair hormone levels collected on the same day after delivery no longer showed effects of the disturbance earlier during pregnancy. This study documents that a period of acute stress, lasting for 20% of gestation, has sustained effects on the hormones to which a developing fetus is exposed. PMID:26802598

  6. Levels of methylmercury and controlling factors in surface sediments of the Carson River system, Nevada

    SciTech Connect

    Chen, Y.; Bonzongo, J.C.; Miller, G.C.

    1995-12-31

    Spatial and temporal distribution of MeHg, as well as, its relationships with both the biotic and abiotic activities, were determined in surficial sediments collected from a river-reservoir system, severely impacted by Hg-contaminated mine wastes. Despite the fact that total mercury concentrations in surface sediments of the Carson River system were in the {mu}g.g{sup -1} range, levels of MeHg varied from {approximately}1 to 28 ng Hg.g{sup -1} dry weight, representing less than 3% of Total-Hg. Positive relationships were obtained between MeHg concentrations and both the chemical activity and general rate of biotic activity, suggesting the contribution of both the abiotic and biotic processes in the production of MeHg in natural environments, the latter being more important and more significant. Laboratory investigations showed that rates of MeHg production in sediments of the Carson River were affected by factors related to peculiarities of this aquatic system.

  7. Human milk as a source of methylmercury exposure in infants

    SciTech Connect

    Grandjean, P. ); Jorgensen, P.J. ); Weihe, P. )

    1994-01-01

    As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 [mu]g/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. As increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity. 25 refs., 2 figs., 3 tabs.

  8. Hair cadmium level of smoker and non-smoker human volunteers in and around Calcutta City

    SciTech Connect

    Chattopadhyay, P.K.; Samaddar, K.R. ); Joshi, H.C. )

    1990-08-01

    In recent years considerable interest has arisen concerning cadmium accumulation in man. In general, the body burden of cadmium of an urban population is due to occupational exposure, as well as non-occupational contamination. Several reports indicate that cadmium body burden of cigarette smokers or tobacco users is more than of non-smokers. Measurement of cadmium in human hair has been suggested as an indicator of body burden. Most industrialized countries have regular monitoring programs for measuring cadmium accumulation in humans. There has been little or no work done thus far in India regarding the level of cadmium in humans. The objective of this investigation was to survey the levels of cadmium in hair of random samples of human volunteers. The influences of smoking habits, urban or rural life and age of the volunteers on the level of cadmium in hair were examined.

  9. Methylmercury monitoring study in Karakuwacho peninsula area in Japan.

    PubMed

    Yan, Junxia; Inoue, Kayoko; Asakawa, Akihiro; Harada, Kouji H; Watanabe, Takao; Hachiya, Noriyuki; Koizumi, Akio

    2014-07-01

    Methylmercury (MeHg) is a worldwide concern owing to its adverse health effects. To explore MeHg exposure burdens and the potential contributing factors in different subpopulations in a peninsula area (Karakuwacho) in Japan, a cross-sectional survey was performed. This study included 189 individuals from 102 families. The geometric means of total hair mercury (THg) were 5.74, 3.78 and 2.37 μg/g for adult males, females and children, respectively, of which 56.5 %, 30.9 % and 12.9 % had hair THg exceeding 5 μg/g, respectively. Tuna and mackerel were the common fish species that were positively correlated with hair THg levels in different subpopulations (standardized coefficient ranged from 0.20 to 0.58, p < 0.05). Frequent consumption of these fish species and a large amount of fish intake are likely major contributors of MeHg exposure in this area. Local-scale risk evaluation and risk communication should be highlighted in future studies. PMID:24599146

  10. Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China.

    PubMed

    Chen, Zhuo; Li, Hairong; Yang, Linsheng; Wang, Wuyi; Li, Yonghua; Gong, Hongqiang; Guo, Min; Nima, Cangjue; Zhao, Shengcheng; Wang, Jing; Ye, Bixiong; Danzeng, Sangbu; Deji, Yangzong

    2015-11-01

    Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15 years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232 μg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255 μg/g) and the girls (0.222 μg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3 % of students with low Se status (hair Se <0.20 μg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa. PMID:25910897

  11. Hair Mercury and Fish Consumption in Residents of O‘ahu, Hawai‘i

    PubMed Central

    Quintana, Penelope JE; Ji, Ming

    2014-01-01

    Recent studies have established that men are susceptible to cardiotoxicity from methylmercury exposure, which also poses risks to the pregnant woman. Hair samples were obtained and questionnaires for methylmercury exposure assessment were administered to 110 adults (57 men, 53 women) throughout O‘ahu, Hawai‘i during December 2010 to January 2011. Hair samples were analyzed for total mercury with a direct mercury analyzer. Men ≥ 46 years had a median of 2.0 µg/g, which was above the reference dose of 1 µg/g, as compared to younger men with a median 1.0 µg/g (P < 0.05). Hair concentrations from older women had a median of 1.2 µg/g of mercury compared to 0.6 µg/g for younger women. Additionally, 38% of women of childbearing age had a Hazard Index > 1.0. This indicates that both men and women were at risk for excessive methylmercury exposure. In the final regression model, male gender, age > 45 years, length of residency > 10 years in Hawai‘i, and fish consumption frequency > 1 meal per week were significant factors in increased hair mercury levels. Following safe fish consumption practices allows residents to reap health benefits of fish consumption without excessive toxicant exposure. PMID:24470983

  12. Transforming growth factor alpha treatment alters intracellular calcium levels in hair cells and protects them from ototoxic damage in vitro.

    PubMed

    Staecker, H; Dazert, S; Malgrange, B; Lefebvre, P P; Ryan, A F; Van de Water, T R

    1997-07-01

    To determine if transforming growth factor alpha (TGF alpha) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10(-3) M) exposure either with or without growth factor pretreatment. After TGF alpha (500 ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGF alpha in organ of Corti explants. PMID:9263032

  13. Childhood abuse is associated with increased hair cortisol levels among urban pregnant women

    PubMed Central

    Schreier, Hannah M C; Enlow, Michelle Bosquet; Ritz, Thomas; Gennings, Chris; Wright, Rosalind J

    2015-01-01

    Background Hypothalamic–pituitary–adrenal (HPA) axis activity is known to be altered following events such as childhood abuse. However, despite potential adverse consequences for the offspring of women who have experienced abuse, very little is known about altered HPA axis activity during pregnancy. Methods During pregnancy, 180 women from diverse racial/ethnic backgrounds reported on their exposure to emotional, physical and/or sexual abuse before the age of 11, and general post-traumatic stress symptoms (ie, not limited to childhood years or abuse experiences). Around delivery, they provided hair samples for the assessment of cortisol levels during pregnancy. Hair cortisol was assessed for each pregnancy trimester. The effect of childhood abuse on hair cortisol was assessed using mixed-effects analyses of covariance models allowing for within-subject correlated observations, and were first performed in the entire sample and subsequently stratified by race/ethnicity. Results Controlling for post-traumatic stress symptoms, hair cortisol levels varied by history of child abuse, F(2,166)=3.66, p=0.028. Childhood physical and/or sexual abuse was associated with greater hair cortisol levels, t(166)=2.65, p=0.009, compared with no history of abuse. Because childhood rates of abuse and hair cortisol levels varied by race/ethnicity, analyses were stratified by race/ethnicity. The associations between history of abuse and cortisol levels were only significant among black women, F(2,23)=5.37, p=0.012. Conclusions Childhood abuse, especially physical and/or sexual abuse, is associated with differences in cortisol production during pregnancy, particularly among black women. Future research should investigate how these differences impact physical and mental health outcomes among offspring of affected women. PMID:26219886

  14. Chronic methylmercurialism in the cat.

    PubMed

    Gruber, T A; Costigan, P; Wilkinson, G T; Seawright, A A

    1978-04-01

    The mercury levels in 69 muscle samples from fish weighing from 0.3 to 200 kg caught in Moreton Bay, Queensland, in the latter half of 1976 ranged from less than 10 to 2,030 ng/g. Mercury levels in blood samples from 53 humans and 100 dogs in Brisbane almost all contained less than 10 ng/ml while the level in 162 cats sampled ranged from less than 10 to 329 ng/ml. Chronic methylmercurialism developed in 2 cats dosed daily with methylmercury, bound to cysteine, at the rate of 0.6 mg/kg body weight for 74 and 77 days respectively. Terminal clinical signs included anorexia, weight loss, knuckling over at the carpus and tarsus, hypermetria initially involving the forelegs and later the hindlegs, sluggish reflexes, paresis involving all limbs, persistent crying, apparent blindness, tonic and clonic convulsions and salivation. Pathological changes were confined to the nervous system and included degeneration of neurones and perivascular cuffing in the cerebrocortical grey matter, focal atrophy of the granular layer, focal spongiosus of the molecular layer and degeneration and loss of Purkinje cells in the cerebellum and demyelination in the fibre tracts of the dorsal funiculus, mainly the fasciculus cuneatus and in the lateral and ventral corticospinal tracts. Terminal blood methylmercury levels were in excess of 18 microgram/ml, while brain methylmercury levels ranged from 21.0 to 28.4 microgram/g. The liver and kidney contained the highest total levels of mercury of 50 to 80 microgram/g, of which 23 to 37% was inorganic. PMID:687273

  15. The diagnostics of diabetes mellitus based on ensemble modeling and hair/urine element level analysis.

    PubMed

    Chen, Hui; Tan, Chao; Lin, Zan; Wu, Tong

    2014-07-01

    The aim of the present work focuses on exploring the feasibility of analyzing the relationship between diabetes mellitus and several element levels in hair/urine specimens by chemometrics. A dataset involving 211 specimens and eight element concentrations was used. The control group was divided into three age subsets in order to analyze the influence of age. It was found that the most obvious difference was the effect of age on the level of zinc and iron. The decline of iron concentration with age in hair was exactly consistent with the opposite trend in urine. Principal component analysis (PCA) was used as a tool for a preliminary evaluation of the data. Both ensemble and single support vector machine (SVM) algorithms were used as the classification tools. On average, the accuracy, sensitivity and specificity of ensemble SVM models were 99%, 100%, 99% and 97%, 89%, 99% for hair and urine samples, respectively. The findings indicate that hair samples are superior to urine samples. Even so, it can provide more valuable information for prevention, diagnostics, treatment and research of diabetes by simultaneously analyzing the hair and urine samples. PMID:24835087

  16. Lead exposure and hair lead level of workers in a lead refinery industry in Iran

    PubMed Central

    Pirsaraei, Seyed Reza Azimi

    2007-01-01

    This study was carried out on the workers of a lead refinery industry and two control groups in Zanjan city in Iran. The scalp hair samples were collected from 25 workers who were occupationally exposed to lead contamination as a case group and from 25 subjects among the staff of the same industry and 25 subjects among Zanjan citizens as the first and second control groups respectively. A flame atomic absorption spectrophotometer used to determine lead level in all of the samples. The age of all subjects in the three groups was matched. The mean concentrations of hair lead in the workers (case group), the staff (control groupA) and the citizens (control group B) were 131.7±93.4 µgr/gr, 21.1±13.2 µgr/gr and 27.9±14.1 µgr/gr respectively. The mean concentration of hair lead in the case group was more than hair lead of normal range found in humans (0-30 µgr/gr). The mean of hair lead level in the citizens who had used gas vehicles was statistically higher than who had not used it (36.9±12.2 µgr/gr vs. 16.6±4.9 µgr/gr, P<0.001). PMID:21957365

  17. Arsenic levels in blood, urine, and hair of workers applying monosodium methanearsonate (MSMA)

    SciTech Connect

    Abdelghani, A.A.; Anderson, A.C.; Jaghabir, M.; Mather, F.

    1986-05-01

    Uptake and excretion of total arsenic from monosodium methanearsonate (MSMA) in workers who applied the herbicide was followed during the spraying season. Urine, blood, and hair samples were collected and air samples were taken from the workers' breathing zone. Arsenic concentrations in air samples ranged from 0.001-1.086 micrograms/m3. Blood and urine arsenic values ranged from 0.0-0.2 mg/L and 0.002-1.725 mg/L, respectively. The geometric mean arsenic concentration in urine increased during the week but returned to base levels on weekends. Hair arsenic concentrations ranged from 0.02-358.0 mg/kg, increased during the spraying season, and returned to pre-season levels once herbicide application ceased. Three workers had higher than normal pre-exposure hair values. However, only one of the three workers had consistently above normal values throughout the study period.

  18. The effects of prenatal methylmercury exposure on trace element and antioxidant levels in rats following 6-hydroxydopamine-induced neuronal insult.

    PubMed

    Mohamed Moosa, Zulfiah; Daniels, Willie M U; Mabandla, Musa V

    2014-06-01

    Methylmercury (MeHg) is a metal toxin found commonly in the environment. Studies have shown severe neurotoxic effects of MeHg poisoning especially during pregnancy where it crosses the foetoplacental and the blood brain barrier of the foetus leading to neurodevelopmental deficits in the offspring. These deficits may predispose offspring to neurodegenerative diseases later in life. In this study we investigated the effects of prenatal methylmercury exposure (2.5 mg/L in drinking water from GND 1-GND 21) on the trace element status in the brain of adolescent offspring (PND 28). Total antioxidant capacity (TAC) was measured in their blood plasma. In a separate group of animals that was also exposed prenatally to MeHg, 6-hydroydopamine (6-OHDA) was administered at PND 60 as a model of neuronal insult. Trace element and TAC levels were compared before and after 6-OHDA exposure. Prenatal MeHg treatment alone resulted in significantly higher concentrations of zinc, copper, manganese and selenium in the brain of offspring at PND 28 (p < 0.05), when compared to controls. In contrast, brain iron levels in MeHg-exposed adolescent offspring were significantly lower than their controls (p < 0.05). Following 6-OHDA exposure, the levels of iron, zinc, copper and manganese were increased compared to sham-lesioned offspring (p < 0.05). Prenatal MeHg exposure further increased these trace element levels thereby promoting toxicity (p < 0.05). Total antioxidant capacity was not significantly different in MeHg and control groups prior to lesion. However, following 6-OHDA administration, MeHg-exposed animals had a significantly lower TAC than that of controls (p < 0.05). Brain TAC levels were higher in adult male rats than in female rats during adolescence however male rats that had been exposed to MeHg in utero failed to show this increase at PND 74. Prenatal MeHg exposure results in trace element dyshomeostasis in the brain of offspring and reduces total

  19. Transport of pyruvate into mitochondria is involved in methylmercury toxicity

    PubMed Central

    Lee, Jin-Yong; Ishida, Yosuke; Takahashi, Tsutomu; Naganuma, Akira; Hwang, Gi-Wook

    2016-01-01

    We have previously demonstrated that the overexpression of enzymes involved in the production of pyruvate, enolase 2 (Eno2) and D-lactate dehydrogenase (Dld3) renders yeast highly sensitive to methylmercury and that the promotion of intracellular pyruvate synthesis may be involved in intensifying the toxicity of methylmercury. In the present study, we showed that the addition of pyruvate to culture media in non-toxic concentrations significantly enhanced the sensitivity of yeast and human neuroblastoma cells to methylmercury. The results also suggested that methylmercury promoted the transport of pyruvate into mitochondria and that the increased pyruvate concentrations in mitochondria were involved in intensifying the toxicity of methylmercury without pyruvate being converted to acetyl-CoA. Furthermore, in human neuroblastoma cells, methylmercury treatment alone decreased the mitochondrial membrane potential, and the addition of pyruvate led to a further significant decrease. In addition, treatment with N-acetylcysteine (an antioxidant) significantly alleviated the toxicity of methylmercury and significantly inhibited the intensification of methylmercury toxicity by pyruvate. Based on these data, we hypothesize that methylmercury exerts its toxicity by raising the level of pyruvate in mitochondria and that mitochondrial dysfunction and increased levels of reactive oxygen species are involved in the action of pyruvate. PMID:26899208

  20. Dose validation of PhIP hair level as a biomarker of heterocyclic aromatic amines exposure: a feeding study.

    PubMed

    Le Marchand, Loïc; Yonemori, Kim; White, Kami K; Franke, Adrian A; Wilkens, Lynne R; Turesky, Robert J

    2016-07-01

    Hair measurement of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a promising biomarker of exposure to this carcinogen formed in cooked meats. However, the dose relationship between normal range intake and hair levels and the modulating effects of CYP1A2 metabolism and hair melanin need to be evaluated. We conducted a randomized, cross-over feeding study among 41 non-smokers using ground beef cooked to two different levels of doneness, 5 days a week for 1 month. PhIP was measured by liquid chromatography/mass spectrometry in food (mean low dose = 0.72 µg/serving; mean high dose = 2.99 µg/serving), and change in PhIP hair level was evaluated. CYP1A2 activity was assessed in urine with the caffeine challenge test and head hair melanin was estimated by UV spectrophotometry. We observed a strong dose-dependent increase in hair PhIP levels. This increase was highly correlated with dose received (ρ = 0.68, P < 0.0001). CYP1A2 activity and normalizing for hair melanin did not modify the response to the intervention. Consumption of PhIP at doses similar to those in the American diet results in a marked dose-dependent accumulation of PhIP in hair. Hair PhIP levels may be used as a biomarker of dietary exposure in studies investigating disease risk. PMID:27207666

  1. Organ-level quorum sensing directs regeneration in hair stem cell populations

    PubMed Central

    Chen, Chih-Chiang; Wang, Lei; Plikus, Maksim V.; Jiang, Ting Xin; Murray, Philip J.; Ramos, Raul; Guerrero-Juarez, Christian F.; Hughes, Michael W; Lee, Oscar K.; Shi, Songtao; Widelitz, Randall B.; Lander, Arthur D.; Chuong, Cheng Ming

    2015-01-01

    SUMMARY Coordinated organ behavior is crucial for an effective response to environmental stimuli. By studying regeneration of hair follicles in response to patterned hair removal, we demonstrate that organ-level quorum sensing allows coordinated responses to skin injury. Removing hair at different densities leads to a regeneration of up to 5 times more neighboring, unplucked resting hairs, indicating activation of a collective decision-making process. Through data modeling, the range of the quorum signal was estimated to be on the order of 1 mm, greater than expected for a diffusible molecular cue. Molecular and genetic analysis uncovered a two-step mechanism, where release of CCL2 from injured hairs leads to recruitment of TNF-α secreting macrophages, which accumulate and signal to both plucked and unplucked follicles. By coupling immune response with regeneration, this mechanism allows skin to respond predictively to distress, disregarding mild injury, while meeting stronger injury with full-scale cooperative activation of stem cells. PMID:25860610

  2. Analysis of hair cortisol levels in captive chimpanzees: Effect of various methods on cortisol stability and variability

    PubMed Central

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Suzuki, Juri; Hayashi, Misato; Kinoshita, Kodzue; Murayama, Miho; Idani, Gen’ichi

    2016-01-01

    Hair cortisol has been reported to be a useful measure of long-term hypothalamic–pituitary–adrenal (HPA) axis activation in several species. It serves as a practical tool for long-term stress assessment, but it is important to understand the methodological factors that can affects hair cortisol assays to avoid methodological artifacts. To that end, we tested several procedures for measuring cortisol levels in hair collected from captive chimpanzees. The results showed that reproducibility was high, and we found no differences in cortisol levels among the various storage, drying, and sampling methods. However, the fineness of homogenized hair, sample weight, and extraction time affected absolute hair cortisol concentration. Although hair cortisol levels were stable over time, factors that may influence measurement results should be kept constant throughout a study.•We modified and validated a methodology involving enzyme immunoassays to reliably measure the hair cortisol levels of captive chimpanzees.•The results revealed that the fineness of homogenized hair, sample weight, and extraction time caused variations in absolute hair cortisol concentrations in chimpanzees. In contrast, storage, drying, and sampling from similar body parts did not affect the results. PMID:26870668

  3. Analysis of hair cortisol levels in captive chimpanzees: Effect of various methods on cortisol stability and variability.

    PubMed

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Suzuki, Juri; Hayashi, Misato; Kinoshita, Kodzue; Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Hair cortisol has been reported to be a useful measure of long-term hypothalamic-pituitary-adrenal (HPA) axis activation in several species. It serves as a practical tool for long-term stress assessment, but it is important to understand the methodological factors that can affects hair cortisol assays to avoid methodological artifacts. To that end, we tested several procedures for measuring cortisol levels in hair collected from captive chimpanzees. The results showed that reproducibility was high, and we found no differences in cortisol levels among the various storage, drying, and sampling methods. However, the fineness of homogenized hair, sample weight, and extraction time affected absolute hair cortisol concentration. Although hair cortisol levels were stable over time, factors that may influence measurement results should be kept constant throughout a study.•We modified and validated a methodology involving enzyme immunoassays to reliably measure the hair cortisol levels of captive chimpanzees.•The results revealed that the fineness of homogenized hair, sample weight, and extraction time caused variations in absolute hair cortisol concentrations in chimpanzees. In contrast, storage, drying, and sampling from similar body parts did not affect the results. PMID:26870668

  4. Low level laser therapy and hair regrowth: an evidence-based review.

    PubMed

    Zarei, Mina; Wikramanayake, Tongyu C; Falto-Aizpurua, Leyre; Schachner, Lawrence A; Jimenez, Joaquin J

    2016-02-01

    Despite the current treatment options for different types of alopecia, there is a need for more effective management options. Recently, low-level laser therapy (LLLT) was evaluated for stimulating hair growth. Here, we reviewed the current evidence on the LLLT effects with an evidence-based approach, focusing more on randomized controlled studies by critically evaluating them. In order to investigate whether in individuals presenting with hair loss (male pattern hair loss (MPHL), female pattern hair loss (FPHL), alopecia areata (AA), and chemotherapy-induced alopecia (CIA)) LLLT is effective for hair regrowth, several databases including PubMed, Google Scholar, Medline, Embase, and Cochrane Database were searched using the following keywords: Alopecia, Hair loss, Hair growth, Low level laser therapy, Low level light therapy, Low energy laser irradiation, and Photobiomodulation. From the searches, 21 relevant studies were summarized in this review including 2 in vitro, 7 animal, and 12 clinical studies. Among clinical studies, only five were randomized controlled trials (RCTs), which evaluated LLLT effect on male and female pattern hair loss. The RCTs were critically appraised using the created checklist according to the Critical Appraisal for Therapy Articles Worksheet created by the Center of Evidence-Based Medicine, Oxford. The results demonstrated that all the performed RCTs have moderate to high quality of evidence. However, only one out of five studies performed intention-to-treat analysis, and only another study reported the method of randomization and subsequent concealment of allocation clearly; all other studies did not include this very important information in their reports. None of these studies reported the treatment effect of factors such as number needed to treat. Based on this review on all the available evidence about effect of LLLT in alopecia, we found that the FDA-cleared LLLT devices are both safe and effective in patients with MPHL and FPHL

  5. The role of gut microbiota in fetal methylmercury exposure: Insights from a pilot study

    DOE PAGESBeta

    Rothenberg, Sarah E.; Keiser, Sharon; Ajami, Nadim J.; Wong, Matthew C.; Gesell, Jonathan; Petrosino, Joseph F.; Johs, Alexander

    2016-02-01

    The mechanisms by which gut microbiota contribute to methylmercury metabolism remain unclear. Among a cohort of pregnant mothers, the main objectives of our pilot study were to determine 1) associations between gut microbiota and mercury concentrations in biomarkers (stool, hair and cord blood) and 2) the contributions of gut microbial mercury methylation/demethylation to stool methylmercury. Moreover, for pregnant women (36-39 weeks gestation, n=17) donated hair and stool specimens, and cord blood was collected for a subset (n=7). The diversity of gut microbiota was determined using 16S rRNA gene profiling (n=17). For 6 stool samples with highest/lowest methylmercury concentrations, metagenomic wholemore » genome shotgun sequencing was employed to search for one mercury methylation gene (hgcA), and two mer operon genes involved in methylmercury detoxification (merA and merB). There were seventeen bacterial genera that were significantly correlated (increasing or decreasing) with stool methylmercury, stool inorganic mercury, or hair total mercury; however, aside from one genus, there was no overlap between biomarkers. No definitive matches for hgcA or merB, while merA were detected at low concentrations in all six samples. Proportional differences in stool methylmercury were not likely attributed to gut microbiota through methylation/demethylation. Gut microbiota potentially altered methylmercury metabolism using indirect pathways.« less

  6. Increased cortisol levels in hair of recent Ecstasy/MDMA users.

    PubMed

    Parrott, A C; Sands, H R; Jones, L; Clow, A; Evans, P; Downey, L A; Stalder, T

    2014-03-01

    Previous research has revealed an acute 8-fold increase in salivary cortisol following self-administrated Ecstasy/MDMA in dance clubbers. It is currently not known to what extent repeated usage impacts upon activity of the hypothalamic-pituitary-adrenal axis over a more prolonged period of time. This study investigated the integrated cortisol levels in 3-month hair samples from recent Ecstasy/MDMA users and non-user controls. One hundred and one unpaid participants (53 males, 48 females; mean age 21.75 years) completed the University of East London recreational drug use questionnaire, modified to cover the past 3-months of usage. They comprised 32 light recent Ecstasy/MDMA users (1-4 times in last 3 months), 23 recent heavy MDMA users (+5 times in last 3 months), and 54 non-user controls. Volunteers provided 3 cm hair samples for cortisol analysis. Hair cortisol levels were observed to be significantly higher in recent heavy MDMA users (mean = 55.0 ± 80.1 pg/mg), compared to recent light MDMA users (19.4 ± 16.0 pg/mg; p=0.015), and to non-users (13.8 ± 6.1 pg/mg; p<0.001). Hence the regular use of Ecstasy/MDMA was associated with almost 4-fold raised hair cortisol levels, in comparison with non-user controls. The present results are consistent with the bio-energetic stress model for Ecstasy/MDMA, which predicts that repeated stimulant drug use may increase cortisol production acutely, and result in greater deposits of the hormone in hair. These data may also help explain the neurocognitive, psychiatric, and other psychobiological problems of some abstinent users. Future study design and directions for research concerning the psychoneuroendocrinological impact of MDMA are also discussed. PMID:24333019

  7. Association of Hair Manganese Level with Symptoms in Attention-Deficit/Hyperactivity Disorder

    PubMed Central

    Shin, Dong-Won; Kim, Eun-Ji; Lim, Se-Won; Shin, Young-Chul; Oh, Kang-Seob

    2015-01-01

    Objective The study examined the association between hair manganese level and symptoms of attention-deficit/hyperactivity disorder (ADHD) in Korean children. Methods Forty clinic-referred children with ADHD and 43 normal control children participated in this study. The participants were 6-15 years old and were mainly from the urban area of Seoul, Korea. ADHD was diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition and Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version-Korean Version. The severity and symptoms of ADHD was evaluated according to the ADHD Diagnostic System, and parent's Korean ADHD Rating Scale (K-ARS). All participants completed intelligence test and hair mineral analysis. We divided the data of hair Mn into two groups to determine whether a deficit or excess of Mn are associated with ADHD. Multiple logistic regression analyses were performed to identify hair manganese levels associated with ADHD, controlling for age, sex, and full scale intelligence quotient (IQ). Results The proportion of abnormal range Mn group was significantly high in ADHD compared to controls. However, after statistical control for covariates including age and sex, abnormal range Mn group was significantly associated with ADHD (OR=6.40, 95% CI=1.39-29.41, p=0.017). Conclusion The result of this study suggests that excess exposure or deficiency of Mn were associated with ADHD among children in Korea. Further investigation is needed to evaluate the effects of hair manganese levels on symptoms in ADHD. PMID:25670948

  8. Rice Methylmercury Exposure and Mitigation: A Comprehensive Review

    PubMed Central

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effect of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, which minimize methylmercury exposure through rice ingestion. PMID:24972509

  9. Rice methylmercury exposure and mitigation: a comprehensive review

    USGS Publications Warehouse

    Rothenberg, Sarah E.; Windham-Myers, Lisamarie; Creswell, Joel E.

    2014-01-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion.

  10. Rice methylmercury exposure and mitigation: a comprehensive review.

    PubMed

    Rothenberg, Sarah E; Windham-Myers, Lisamarie; Creswell, Joel E

    2014-08-01

    Rice cultivation practices from field preparation to post-harvest transform rice paddies into hot spots for microbial mercury methylation, converting less-toxic inorganic mercury to more-toxic methylmercury, which is likely translocated to rice grain. This review includes 51 studies reporting rice total mercury and/or methylmercury concentrations, based on rice (Orzya sativa) cultivated or purchased in 15 countries. Not surprisingly, both rice total mercury and methylmercury levels were significantly higher in polluted sites compared to non-polluted sites (Wilcoxon rank sum, p<0.001). However, rice percent methylmercury (of total mercury) did not differ statistically between polluted and non-polluted sites (Wilcoxon rank sum, p=0.35), suggesting comparable mercury methylation rates in paddy soil across these sites and/or similar accumulation of mercury species for these rice cultivars. Studies characterizing the effects of rice cultivation under more aerobic conditions were reviewed to determine the mitigation potential of this practice. Rice management practices utilizing alternating wetting and drying (instead of continuous flooding) caused soil methylmercury levels to spike, resulting in a strong methylmercury pulse after fields were dried and reflooded; however, it is uncertain whether this led to increased translocation of methylmercury from paddy soil to rice grain. Due to the potential health risks, it is advisable to investigate this issue further, and to develop separate water management strategies for mercury polluted and non-polluted sites, in order to minimize methylmercury exposure through rice ingestion. PMID:24972509

  11. Methylmercury: a new look at the risks.

    PubMed Central

    Mahaffey, K R

    1999-01-01

    In the US, exposure to methylmercury, a neurotoxin, occurs primarily through consumption of fish. Data from recent studies assessing the health impact of methylmercury exposure due to consumption of fish and other sources in the aquatic food web (shellfish, crustacea, and marine mammals) suggest adverse effects at levels previously considered safe. There is substantial variation in human methylmercury exposure based on differences in the frequency and amount of fish consumed and in the fish's mercury concentration. Although virtually all fish and other seafood contain at least trace amounts of methylmercury, large predatory fish species have the highest concentrations. Concerns have been expressed about mercury exposure levels in the US, particularly among sensitive populations, and discussions are underway about the standards used by various federal agencies to protect the public. In the 1997 Mercury Study Report to Congress, the US Environmental Protection Agency summarized the current state of knowledge on methylmercury's effects on the health of humans and wildlife; sources of mercury; and how mercury is distributed in the environment. This article summarizes some of the major findings in the Report to Congress and identifies issues of concern to the public health community. Images p396-a p397-a p399-a p406-a p408-a p410-a PMID:10590759

  12. Comparative observations on levels of mercury in scalp hair of humans from different Islands

    NASA Astrophysics Data System (ADS)

    Renzoni, Aristeo

    1992-09-01

    Following the Minamata events, an extraordinary number of studies concerning mercury toxicity and human health have been undertaken. Particular attention has been given to the evaluation of the dose-response relationship, i.e., the body burden at which (evaluated through the mercury analyses in blood or hair) the risk of poisoning begins. The results of a comparative study concerning levels of mercury in the hair of fishermen living in small islands who eat seafood more than four times per week show that in two areas only, and only in a few cases in these areas, the mercury in the hair exceeds the limit at which a possible risk could exist. In fact, the limit of 50 mg/g of total mercury in the hair (indicated as the lower limit above which a possible risk could occur) is surpassed by nine fishermen out of a total of 39 at station 1 and by four fishermen out of a total of 26 at station 3. The average value at station 1 is 36.38 mg/g and that at station 3 is 30.31 mg. Many countries have set legal limits of mercury for seafood, but evidently the system does not offer a true protection for man. Only the provisional tolerable weekly intake (PTWI), as repeatedly suggested by WHO, should be considered the best guideline to prevent possibly harmful consequences.

  13. Association between trace element and heavy metal levels in hair and nail with prostate cancer.

    PubMed

    Karimi, Golgis; Shahar, Suzana; Homayouni, Nasim; Rajikan, Roslee; Abu Bakar, Nor Faizah; Othman, Mohd Sham

    2012-01-01

    While associations between trace elements and heavy metals with prostate cancer are still debatable, they have been considered as risk factors for prostate cancer. Thus, this study aimed to detect any links between selected minerals and heavy metals including Se, Zn, Cu, Mn and Fe with prostate cancer. A case control study was carried out among 100 subjects (case n=50, control n=50), matched for age and ethnicity. Trace elements and heavy metals level in hair and nail samples were determined by ICP-MS. Mean selenium levels in hair and nail of the cases were significantly lower as compared to controls. A similar trend was noted for zinc in both hair and nail samples, whereas the mean level of copper was significantly higher in cases than controls. Similar elevation was noted for iron and manganese (p<0.05 for all parameters). Low levels of selenium and zinc and high levels of copper, iron and manganese appear to be associated with the risk of prostate cancer. Further studies to elucidate the causal mechanisms and appropriate chemopreventive measures are needed. PMID:23167323

  14. Mercury accumulation in fish species from the Persian Gulf and in human hair from fishermen.

    PubMed

    Agah, Homira; Leermakers, Martine; Gao, Yue; Fatemi, S M R; Katal, M Mohseni; Baeyens, Willy; Elskens, Marc

    2010-10-01

    Total and methylmercury concentrations were assessed in muscle and liver of 141 fish samples from the northern part of the Persian Gulf. All fish samples belonged to five different species: grunt, flathead, greasy grouper, tiger-tooth croaker, and silver pomfret. In addition, Hg and methylmercury were analyzed in scalp hair of 19 fishermen living in the same coastal stations of the Persian Gulf and consuming several fish meals a week. Total mercury concentrations in fish muscle and liver ranged from 0.01 to 1.35 microg g(-1) w.w. and from 0.02 to 1.30 microg g(-1) w.w., respectively. In fish muscle, 3% of the Hg concentrations were higher than 0.5 microg g(-1) w.w., which corresponds to the maximum acceptable WHO level, while 9% were in the range of polluted fish (between 0.3 and 0.5 microg g(-1) w.w.). The highest mercury concentrations in fish muscle were observed in flathead fish at Abadan (average of 0.68 microg g(-1) w.w.). Methylmercury fractions in fish muscle and liver amount to 34-99% (median 64%) and 24-70% (median 43%), respectively. The mean total Hg concentration in the fishermen's scalp hair amounted to 2.9 +/- 2.2 microg g(-1), with 68% in the form of methylmercury. Ninety-five percent of the Hg levels in the fishermen's hair were below 10 microg g(-1), which is the WHO warning limit. In addition, relationships between the mercury levels in hair, on the one hand, and exposure-related factors such as Hg levels in specific fish species, regional differences, and number of fish meals, on the other hand, are discussed. It appears that a significant correlation for example exists between Hg levels human hair and fish muscle or human hair and age and that mean mercury levels in fish muscle and human hair decreased from western (Abadan) to eastern (Abbas port) coastal sites. PMID:19760084

  15. Reducing uncertainty in risk modeling for methylmercury exposure

    SciTech Connect

    Ponce, R.; Egeland, G.; Middaugh, J.; Lee, R.

    1995-12-31

    The biomagnification and bioaccumulation of methylmercury in marine species represents a challenge for risk assessment related to the consumption of subsistence foods in Alaska. Because of the profound impact that food consumption advisories have on indigenous peoples seeking to preserve a way of life, there is a need to reduce uncertainty in risk assessment. Thus, research was initiated to reduce the uncertainty in assessing the health risks associated with the consumption of subsistence foods. Because marine subsistence foods typically contain elevated levels of methylmercury, preliminary research efforts have focused on methylmercury as the principal chemical of concern. Of particular interest are the antagonistic effects of selenium on methylmercury toxicity. Because of this antagonism, methylmercury exposure through the consumption of marine mammal meat (with high selenium) may not be as toxic as comparable exposures through other sources of dietary intake, such as in the contaminated bread episode of Iraq (containing relatively low selenium). This hypothesis is supported by animal experiments showing reduced toxicity of methylmercury associated with marine mammal meat, by the antagonistic influence of selenium on methylmercury toxicity, and by negative clinical findings in adult populations exposed to methylmercury through a marine diet not subject to industrial contamination. Exploratory model development is underway to identify potential improvements and applications of current deterministic and probabilistic models, particularly by incorporating selenium as an antagonist in risk modeling methods.

  16. N-acetylcysteine as an antidote in methylmercury poisoning.

    PubMed Central

    Ballatori, N; Lieberman, M W; Wang, W

    1998-01-01

    Methylmercury is a ubiquitous environmental pollutant and potent neurotoxin. Treatment of methylmercury poisoning relies almost exclusively on the use of chelating agents to accelerate excretion of the metal. The present study demonstrates that oral administration of N-acetylcysteine (NAC), a widely available and largely nontoxic amino acid derivative, produces a profound acceleration of urinary methylmercury excretion in mice. Mice that received NAC in the drinking water (10 mg/ml) starting at 48 hr after methylmercury administration excreted from 47 to 54% of the 203Hg in urine over the subsequent 48 hr, as compared to 4-10% excretion in control animals. When NAC-containing water was given from the time of methylmercury administration, it was even more effective at enhancing urinary methylmercury excretion and at lowering tissue mercury levels. In contrast, excretion of inorganic mercury was not affected by oral NAC administration. The ability of NAC to enhance methylmercury excretion when given orally, its relatively low toxicity, and is wide availability in the clinical setting indicate that it may be an ideal therapeutic agent for use in methylmercury poisoning. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:9520359

  17. Levels of metals in hair of young children as an indicator of environmental pollution

    SciTech Connect

    Wibowo, A.A.; Herber, R.F.; Das, H.A.; Roeleveld, N.; Zielhuis, R.L.

    1986-08-01

    In 1982 the levels of lead (Pb), cadmium (Cd), vanadium (V), copper (Cu), and selenium (Se) were determined in hair of 231 four- to five-year-old children. The objective was to explore the feasibility of using metal-in-hair levels in groups of children as an indicator of environmental pollution. The study was carried out in four areas, which were assumed to differ in ambient pollution by metals. A questionnaire on personal data, socioeconomic status, intake of beverages, and life-style was completed by the parents. The metal-in-hair levels covered a large range. The variables pertaining to location together with sex, presence of a garden, and drinking of coffee and/or tea explained 32% of the variance of Pb, 24% of the variance of Cd, and 21% of the variance of V. The total variance explained by all measured questionnaire items was at best 38%. The location was the most important factor. Cu and Se levels did not differ between the locations.

  18. Health risks from increases in methylmercury exposure.

    PubMed Central

    Mottet, N K; Shaw, C M; Burbacher, T M

    1985-01-01

    Our present knowledge of the human health effects of methylmercury exposure is derived from study of major outbreaks of human poisonings in Japan and Iraq and experimental studies on primates. Methylmercury readily passes through such physiological barriers as the blood-brain barrier, blood-testes barrier, and the placenta. Its major pathological effects are on the nervous and reproductive systems and the developing embryo/fetus. The neurotoxicity of methylmercury is well established in both humans and non-human primates. Lesions in the cerebral and cerebellar gray matter consist of necrosis and lysis of neurons, phagocytosis and gliosis. The changes are most prominent in the deep sulci and may have a vascular component. A late effect is cerebral atrophy. At high dose levels the liver, kidneys, and other organs may also have degenerative changes. Although not yet described in humans, a major effect of exposure of female primates is an adverse effect on pregnancy. Maternal female M. fascicularis blood mercury levels above 1 ppm are associated with a decreased pregnancy rate and increased abortion rate. To date our experimental data lack sufficient numbers to detect infrequent pregnancy effects below 1 ppm. Preliminary studies also reveal that methylmercury may also decrease the number and function (swim speed) of sperm. Both human and primate studies demonstrate deleterious effects of methylmercury on the developing embryo/fetus. Autopsies on human and primate infants reveal retarded brain development and the occurrence of a cerebral palsy-like behavior in the newborns, whereas the mother may be free of signs and symptoms of methylmercury toxicity. The fetal blood level of mercury is higher than the maternal level.(ABSTRACT TRUNCATED AT 250 WORDS) Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 5. PMID:3908085

  19. Levels of cadmium and mercury in the hair of Atlantic walruses (Odobenus rosmarus rosmarus) from Svalbard, Norway

    SciTech Connect

    Wiig, O.; Renzoni, A.; Gjertz, I.

    1999-08-01

    Hair samples of 15 adult male Atlantic walruses (Odobenus rosmarus rosmarus) collected from anesthetized individuals at Svalbard, Norway, were analyzed for cadmium and total mercury. The mean level of cadmium was 0.860 {+-} 0.321 {micro}g/g dry weight and the mean level of mercury was 0.235 {+-} 0.100 {micro}g/g dry weight. Levels of cadmium and mercury in hair of walruses from other areas are not known. Both cadmium and mercury levels in hair of walruses from Svalbard are relatively low compared to the levels found in the hair of other marine mammal species. It has been documented from a number of marine species, including marine mammals such as ringed seals and polar bears, that both cadmium and mercury levels of Svalbard are lower than in other areas. It is uncertain as to what degree levels in hair reflect levels in internal organs in walruses. In rare and highly endangered species or populations tissue samples can be difficult to collect. In walruses, it is possible to collect hair from anesthetized individuals or at the haul-out sites during molt, to monitor heavy metal levels of the population.

  20. Hair arsenic levels and prevalence of arsenicosis in three Cambodian provinces.

    PubMed

    Hashim, Jamal Hisham; Radzi, Rozhan Syariff Mohamed; Aljunid, Syed Mohamed; Nur, Amrizal Muhammad; Ismail, Aniza; Baguma, David; Sthiannopkao, Suthipong; Phan, Kongkea; Wong, Ming Hung; Sao, Vibol; Yasin, Mohamed Salleh Mohamed

    2013-10-01

    Natural, inorganic arsenic contamination of groundwater threatens the health of more than 100 million people worldwide, including residents of the densely populated river deltas of South and Southeast Asia. Contaminated groundwater from tube wells in Cambodia was discovered in 2001 leading to the detection of the first cases of arsenicosis in 2006. The most affected area was the Kandal Province. The main objective of this study was to determine the prevalence of arsenicosis in Cambodia based on acceptable criteria, and to investigate the use of hair arsenic as a biomarker not only for arsenicosis-related signs but also for associated symptoms. A cross-sectional epidemiological study of 616 respondents from 3 purposely selected provinces within the Mekong River basin of Cambodia was conducted. The Kandal Province was chosen as a high arsenic-contaminated area, while the Kratie Province and Kampong Cham Province were chosen as moderate and low arsenic-contaminated areas, respectively. The most prevalent sign of arsenicosis was hypomelanosis with a prevalence of 14.5% among all respondents and 32.4% among respondents with a hair arsenic level of ≥1 μg/g. This was followed by hyperkeratosis, hyperpigmentation and mee's lines. Results also suggest a 1.0 μg/g hair arsenic level to be a practical cut off point for an indication of an arsenic contaminated individual. This hair arsenic level, together with the presence of one or more of the classical signs of arsenicosis, seems to be a practical criteria for a confirmed diagnosis. Based on these criteria, the overall prevalence of arsenicosis for all provinces was found to be 16.1%, with Kandal Province recording the highest prevalence of 35.5%. This prevalence is comparatively high when compared to that of other affected countries. The association between arsenicosis and the use of Chinese traditional medicine also needs further investigation. PMID:23759330

  1. Feasibility of hair sampling to assess levels of organophosphate metabolites in rural areas of Sri Lanka.

    PubMed

    Knipe, D W; Jayasumana, C; Siribaddana, S; Priyadarshana, C; Pearson, M; Gunnell, D; Metcalfe, C; Tzatzarakis, M N; Tsatsakis, A M

    2016-05-01

    Measuring chronic pesticide exposure is important in order to investigate the associated health effects. Traditional biological samples (blood/urine) are difficult to collect, store and transport in large epidemiological studies in settings such as rural Asia. We assessed the acceptability of collecting hair samples from a rural Sri Lankan population and found that this method of data collection was feasible. We also assessed the level of non-specific metabolites (DAPS) of organophosphate pesticides in the hair samples. The median concentration (pg/mg) of each DAP was: diethyl phosphate: 83.3 (IQI 56.0, 209.4); diethyl thiophosphate: 34.7 (IQI 13.8, 147.9); diethyl dithiophosphate: 34.5 (IQI 23.4, 55.2); and dimethyl phosphate: 3 (IQI 3, 109.7). Total diethylphosphates were recovered in >80% of samples and were positively correlated with self-reported pesticide exposure. PMID:26894816

  2. Feasibility of hair sampling to assess levels of organophosphate metabolites in rural areas of Sri Lanka

    PubMed Central

    Knipe, D.W.; Jayasumana, C.; Siribaddana, S.; Priyadarshana, C.; Pearson, M.; Gunnell, D.; Metcalfe, C.; Tzatzarakis, M.N.; Tsatsakis, A.M.

    2016-01-01

    Measuring chronic pesticide exposure is important in order to investigate the associated health effects. Traditional biological samples (blood/urine) are difficult to collect, store and transport in large epidemiological studies in settings such as rural Asia. We assessed the acceptability of collecting hair samples from a rural Sri Lankan population and found that this method of data collection was feasible. We also assessed the level of non-specific metabolites (DAPS) of organophosphate pesticides in the hair samples. The median concentration (pg/mg) of each DAP was: diethyl phosphate: 83.3 (IQI 56.0, 209.4); diethyl thiophosphate: 34.7 (IQI 13.8, 147.9); diethyl dithiophosphate: 34.5 (IQI 23.4, 55.2); and dimethyl phosphate: 3 (IQI 3, 109.7). Total diethylphosphates were recovered in >80% of samples and were positively correlated with self-reported pesticide exposure. PMID:26894816

  3. Serum Vitamin D3 Level in Patients with Female Pattern Hair Loss

    PubMed Central

    Banihashemi, Mahnaz; Nahidi, Yalda; Meibodi, Naser Tayyebi; Jarahi, Lida; Dolatkhah, Mojgan

    2016-01-01

    Background: Female pattern hair loss (FPHL) is the most common cause of alopecia in women, characterized by diffuse nonscarring hair loss in frontal, central, and parietal areas of the scalp. Pathophysiology of FPHL is still not well known, and it is probably a multifactorial genetic trait. FPHL is also observed in women without increased androgen levels, which raises the likelihood of androgen-independent mechanisms and explains the lack of response to antiandrogen treatments in some patients. Vitamin D is a factor that has recently been considered in dealing with these patients. The purpose of this study was to evaluate the serum levels of Vitamin D in patients with FPHL and compare it with healthy controls. Methods: In this case-control study, 45 women with FPHL were evaluated as well as the same number of healthy women matched for age, hours spent under sunlight per day, and body mass index. Serum 25(OH) D3 level was measured using ELISA. Results: 60% of FPHL patients were in 15–30 years old age group with the mean standard deviation (SD) age of 29.11 (7.30) years. In the majority of patients (66.7%), severity of hair loss was Ludwig I. Mean (SD) serum Vitamin D3 level in patient and control group was 13.45 (8.40) and 17.16 (8.96), respectively. T-test showed a significant difference between the two groups in terms of Vitamin D3 serum levels (P = 0.04). Conclusions: This study indicated the correlation between the incidence of FPHL and decreased serum levels of Vitamin D3. It is recommended to evaluate serum Vitamin D3 levels as well as other hormone assays in these patients. PMID:27625563

  4. Negative Confounding by Essential Fatty Acids in Methylmercury Neurotoxicity Associations

    PubMed Central

    Choi, Anna L; Mogensen, Ulla B.; Bjerve, Kristian S.; Debes, Frodi; Weihe, Pal; Grandjean, Philippe; Budtz-Jørgensen, Esben

    2014-01-01

    Background Methylmercury, a worldwide contaminant of fish and seafood, can cause adverse effects on the developing nervous system. However, long-chain n-3 polyunsaturated fatty acids in seafood provide beneficial effects on brain development. Negative confounding will likely result in underestimation of both mercury toxicity and nutrient benefits unless mutual adjustment is included in the analysis. Methods We examined these associations in 176 Faroese children, in whom prenatal methylmercury exposure was assessed from mercury concentrations in cord blood and maternal hair. The relative concentrations of fatty acids were determined in cord serum phospholipids. Neuropsychological performance in verbal, motor, attention, spatial, and memory functions was assessed at 7 years of age. Multiple regression and structural equation models (SEMs) were carried out to determine the confounder-adjusted associations with methylmercury exposure. Results A short delay recall (in percent change) in the California Verbal Learning Test (CVLT) was associated with a doubling of cord blood methylmercury (−18.9, 95% confidence interval [CI] = −36.3, −1.51). The association became stronger after the inclusion of fatty acid concentrations in the analysis (−22.0, 95% confidence interval [CI] = −39.4, −4.62). In structural equation models, poorer memory function (corresponding to a lower score in the learning trials and short delay recall in CVLT) was associated with a doubling of prenatal exposure to methylmercury after the inclusion of fatty acid concentrations in the analysis (−1.94, 95% CI = −3.39, −0.49). Conclusions Associations between prenatal exposure to methylmercury and neurobehavioral deficits in memory function at school age were strengthened after fatty acid adjustment, thus suggesting that n-3 fatty acids need to be included in analysis of similar studies to avoid underestimation of the associations with methylmercury exposure. PMID:24561639

  5. Methylmercury exposure and neurological outcomes in Taiji residents accustomed to consuming whale meat.

    PubMed

    Nakamura, Masaaki; Hachiya, Noriyuki; Murata, Ken-ya; Nakanishi, Ichiro; Kondo, Tomoyoshi; Yasutake, Akira; Miyamoto, Ken-ichiro; Ser, Ping Han; Omi, Sanae; Furusawa, Hana; Watanabe, Chiho; Usuki, Fusako; Sakamoto, Mineshi

    2014-07-01

    Methylmercury (MeHg) is a major environmental neurotoxicant that causes damage to the central nervous system. In Japan, industrial emission of MeHg has resulted in MeHg intoxication in Minamata and Niigata, the so-called Minamata disease. Humans are exposed to MeHg derived from natural sources, primarily fish and fish predators. Therefore, MeHg continues to be an environmental risk to human health, particularly in susceptible populations that frequently consume substantial amounts of fish or fish predators such as whale. This study aimed to investigate the health effects of MeHg exposure in adults. The subjects were 194 residents (117 males, 77 females; age 20-85 years) who resided in the coastal town of Taiji, the birthplace of traditional whaling in Japan. We analyzed hair for mercury content and performed detailed neurological examinations and dietary surveys. Audiometry, magnetic resonance imaging, and electromyography were performed to diagnose neurological defects. Whole blood mercury and selenium (Se) levels were measured in 23 subjects. The geometric mean of the hair mercury levels was 14.9 μg/g. Twelve subjects revealed hair mercury levels >50 μg/g (NOAEL) set by WHO. Hair mercury levels significantly correlated with daily whale meat intake. These results suggested that residents in Taiji were highly exposed to MeHg by ingesting MeHg-contaminated whale meat. Multivariate regression analysis demonstrated no significant correlations between hair mercury levels and neurological outcomes, whereas some of the findings significantly correlated with age. A significantly positive correlation between whole blood mercury and Se levels was observed and the whole blood mercury/Se molar ratios of all subjects were <1. These findings suggested that sufficient Se intake might be one of causes of the absence of adverse effects of MeHg exposure in this study. PMID:24685489

  6. REFERENCE DOSE FOR METHYLMERCURY (EXTERNAL REVIEW DRAFT)

    EPA Science Inventory

    In 1997, U.S. EPA issued the Mercury Study Report to Congress (MSRC). Among the assessments in the MSRC was a state-of-the-science evaluation of the health effects of methylmercury. There has been considerable discussion within the scientific community regarding the level of e...

  7. Association of hair iron levels with creativity and psychological variables related to creativity

    PubMed Central

    Takeuchi, Hikaru; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos M.; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Kunitoki, Keiko; Sassa, Yuko; Kawashima, Ryuta

    2013-01-01

    Creativity generally involves the conception of original and valuable ideas. Previous studies have suggested an association between creativity and the dopaminergic system, and that physical activity facilitates creativity. Iron plays a key role in the dopaminergic system and physical activity. Here, we newly investigated the associations between hair iron levels and creativity, dopamine-related traits and states [novelty seeking, extraversion, and vigor (motivational state)], as well as the physical activity level. In the present study, we addressed this issue by performing a hair mineral analysis to determine iron levels and a behavioral creativity test of divergent thinking and related psychological measures among young adults (254 men, 88 women; mean age 20.79 ± 2.03 years). Iron levels did not show any significant association with creativity but displayed significant positive associations with novelty seeking, extraversion, and physical activity level. These results may be partly congruent with the notion that iron plays a key role in the dopaminergic system and imply that iron is important for traits and physical activity, which facilitate creativity. Future interventional or longitudinal studies are warranted to identify any causal effects. PMID:24385960

  8. Methylmercury (MeHg)

    Integrated Risk Information System (IRIS)

    Methylmercury ( MeHg ) ; CASRN 22967 - 92 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarci

  9. Marine biogeochemistry: Methylmercury manufacture

    NASA Astrophysics Data System (ADS)

    Cossa, Daniel

    2013-10-01

    The neurotoxin methylmercury can accumulate in marine food webs, contaminating seafood. An analysis of the isotopic composition of fish in the North Pacific suggests that much of the mercury that enters the marine food web originates from low-oxygen subsurface waters.

  10. Hair Mercury Levels Detection in Fishermen from Sicily (Italy) by ICP-MS Method after Microwave-Assisted Digestion

    PubMed Central

    Giangrosso, Giuseppe; Cammilleri, Gaetano; Macaluso, Andrea; Vella, Antonio; D'Orazio, Nicolantonio; Graci, Stefania; Lo Dico, Gianluigi Maria; Galvano, Fabio; Giangrosso, Margherita; Ferrantelli, Vincenzo

    2016-01-01

    A number of ninety-six hair samples from Sicilian fishermen were examined for total mercury detection by an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method. The mercury levels obtained were compared with mercury levels of 96 hair samples from a control group, in order to assess potential exposure to heavy metals of Sicilian fishermen due to fish consumption and closeness to industrial activities. Furthermore, the mercury levels obtained from hair samples were sorted by sampling area in order to verify the possible risks linked to the different locations. The overall mean concentration in the hair of the population of fishermen was 6.45 ± 7.03 μg g−1, with a highest value in a fisherman of Sciacca (16.48 μg g−1). Hair mercury concentration in fishermen group was significantly higher than in control group (p < 0.01). There was no significant difference in hair total mercury concentrations between sampling areas (p > 0.05). The results of this study indicate a greater risk of exposure to mercury in Sicilian fishermen, in comparison to the control population, due to the high consumption of fish and the close relationship with sources of exposure (ports, dumps, etc.). PMID:27127456

  11. Maternal hair selenium levels as a possible long-term nutritional indicator of recurrent pregnancy loss

    PubMed Central

    2013-01-01

    Background Approximately 1% of all couples trying to conceive will suffer from recurrent pregnancy loss (RPL). Nutritional deficiencies have been postulated as a possible cause of RPL and in particular, selenium deficiency has been associated with reproductive failure in animal studies and more recently, in some human studies. This study was undertaken to assess the maternal hair selenium levels in women with RPL without an identified cause and to compare these results with those of women with successful reproductive histories. Methods Twenty four patients with RPL and twenty four control subjects with at least one successful pregnancy and no pregnancy failures, who were matched for age and ethnicity, were recruited. A questionnaire was completed, which included demographic and social information and a dietary history. Hair samples were collected and analyzed for selenium content by inductively coupled plasma mass spectrometry. Results The control subjects had a higher mean income and had completed more years of education compared with the RPL patients. There was no significant difference in the intake of selenium rich foods between the 2 groups. The patients, however, consumed significantly more fruit, cheese, potatoes and chocolate than the controls. The median (range) selenium content was 0.80 ppm (0.19-4.15) and 0.68 ppm (0.43-3.76) in patients and controls respectively (Mann Whitney U test 209.5 p = 0.74). Conclusions While there were significant differences in the 2 groups with regard to resources, education and diet our results show that hair selenium concentrations and dietary selenium intake, were similar in the two groups. Both groups had low levels of this important element. PMID:24148900

  12. Levels of hormones and cytokines associated with growth in Honamlı and native hair goats.

    PubMed

    Devrim, A K; Elmaz, O; Mamak, N; Sudagidan, M

    2015-01-01

    This study was designed to assess alterations of hormone and cytokine levels associated with growth period during puberty in Honamlı goats which were identified as a new goat breed and had one of the highest meat production potential among the other goat breeds in Turkey. Honamlı goats are originated from native hair goats, so parallel studies of sampling and analyzing were conducted also in native hair goats which have moderate meat production. Blood serum samples of Honamlı (n=90) and native hair goats (n=90) were obtained from the pure herds in Korkuteli and Ka districts of Anatolia. Concentrations of growth hormone (GH), myostatin (MSTN), insulin-like growth factor (IGF), growth hormone releasing hormone (GHRH), growth hormone releasing peptide (GHRP), leptin, transforming growth factor-betal (TGF-β1) and vascular endothelial cell growth factor (VEGF) levels were measured by ELISA in each breed in the age groups of 4, 8 and 12 months. The present results indicate interesting correlations among the age groups and all the examined hormone and cytokine parameters exhibited significant (P<0.05 and P<0.001) differences. The parameters investigated were usually begun to increase after 4 months of age in the both breeds and sexes. Therefore, this paper supported the view that the beginning of hormonal alterations of goats could occur at 4th month of age. The results reported here emphasize the primary role played by GH, MSTN, IGF-1, leptin, GHRH, GHRP, TGF-βi and VEGF in the first year growth period of goats. PMID:26172195

  13. Iron status as a covariate in methylmercury-associated neurotoxicity risk.

    PubMed

    Fonseca, Márlon de Freitas; De Souza Hacon, Sandra; Grandjean, Philippe; Choi, Anna Lai; Bastos, Wanderley Rodrigues

    2014-04-01

    Intrauterine methylmercury exposure and prenatal iron deficiency negatively affect offspring's brain development. Since fish is a major source of both methylmercury and iron, occurrence of negative confounding may affect the interpretation of studies concerning cognition. We assessed relationships between methylmercury exposure and iron-status in childbearing females from a population naturally exposed to methylmercury through fish intake (Amazon). We concluded a census (refuse <20%) collecting samples from 274 healthy females (12-49 years) for hair-mercury determination and assessed iron-status through red cell tests and determination of serum ferritin and iron. Reactive C protein and thyroid hormones was used for excluding inflammation and severe thyroid dysfunctions that could affect results. We assessed the association between iron-status and hair-mercury by bivariate correlation analysis and also by different multivariate models: linear regression (to check trends); hierarchical agglomerative clustering method (groups of variables correlated with each other); and factor analysis (to examine redundancy or duplication from a set of correlated variables). Hair-mercury correlated weakly with mean corpuscular volume (r=.141; P=.020) and corpuscular hemoglobin (r=.132; .029), but not with the best biomarker of iron-status, ferritin (r=.037; P=.545). In the linear regression analysis, methylmercury exposure showed weak association with age-adjusted ferritin; age had a significant coefficient (Beta=.015; 95% CI: .003-.027; P=.016) but ferritin did not (Beta=.034; 95% CI: -.147 to .216; P=.711). In the hierarchical agglomerative clustering method, hair-mercury and iron-status showed the smallest similarities. Regarding factor analysis, iron-status and hair-mercury loaded different uncorrelated components. We concluded that iron-status and methylmercury exposure probably occur in an independent way. PMID:24411835

  14. Hair transplant

    MedlinePlus

    ... this procedure: Scarring Unnatural-looking tufts of new hair growth It is possible that the transplanted hair will ... Most hair transplants result in excellent hair growth within several ... may be needed to create best results. The replaced hairs are ...

  15. Body Hair

    MedlinePlus

    ... girlshealth.gov/ Home Body Puberty Body hair Body hair Even before you get your first period , you ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

  16. Elevated Hair Cortisol Levels among Heroin Addicts on Current Methadone Maintenance Compared to Controls

    PubMed Central

    Yang, Jin; Li, Jifeng; Xu, Guanyi; Zhang, Jing; Chen, Zheng; Lu, Zuhong; Deng, Huihua

    2016-01-01

    Whether methadone maintenance treatment (MMT) can improve the basal function of the hypothalamic–pituitary–adrenal (HPA) axis, which is suppressed by long-term heroin consumption, is a matter of debate. The stress state and depression and anxiety symptoms may affect the basal activity of the HPA axis in MMT patients. However, the effect of psychological factors on HPA activity was not simultaneously controlled in previous studies. This study investigated differences in HPA basal activity between MMT patients and controls using psychological variables as covariates. The participants included 52 MMT patients and 41 age-matched, non-heroin-dependent controls. Psychological states were self-reported with the Perceived Stress Scale, Self-Rating Depression Scale and Self-Rating Anxiety Scale. The hair cortisol level was adopted as a biomarker of HPA basal activity and was determined with liquid chromatography tandem mass spectrometry. The results revealed that MMT patients had significantly higher hair cortisol levels than the controls (p<0.05), but the difference was not significant (p>0.05) when the perceived stress, depression and anxiety scores were used as covariates. We concluded that patients with long-term MMT showed higher basal activity of the HPA axis. The high chronic stress state and increase in depression and anxiety symptoms may mask the suppression effect of methadone on the HPA activity. PMID:27010803

  17. Assessment of cadmium, lead, and nickel levels in hair care products marketed in Turkey.

    PubMed

    Sipahi, Hande; Charehsaz, Mohammad; Sonmez, Ipek; Soykut, Buğra; Erdem, Onur; Aydin, Ahmet

    2014-01-01

    This study evaluated the content of cadmium (Cd), lead (Pb), and nickel (Ni) in 105 hair care products commercially available in Turkey. Cd, Pb, and Ni were detected in 40%, 21.91%, and 94.29% of the samples, respectively. Maximum Cd concentrations were detected in two shampoo samples, and the highest Pb level was found in a hair conditioner, all of them were herbal-based formulations. The highest mean levels of Ni were detected in hairstyling agents. The overall results were lower than the Canadian and German regulatory limits; however, according to the European Council Directive and Turkish Cosmetic Legislation, Cd, Pb, and Ni are listed as the substances that are prohibited in any amounts in cosmetics. Moreover, Ni content of 17.14% of the samples was above the limit of allergic contact dermatitis. It is known that these toxic metals tend to accumulate in body and prolonged use of them may potentially pose threat to human health. Thus, regular market monitoring and safer limits should be seriously considered especially for susceptible groups of the population like the pediatric group. PMID:25423743

  18. Elevated Hair Cortisol Levels among Heroin Addicts on Current Methadone Maintenance Compared to Controls.

    PubMed

    Yang, Jin; Li, Jifeng; Xu, Guanyi; Zhang, Jing; Chen, Zheng; Lu, Zuhong; Deng, Huihua

    2016-01-01

    Whether methadone maintenance treatment (MMT) can improve the basal function of the hypothalamic-pituitary-adrenal (HPA) axis, which is suppressed by long-term heroin consumption, is a matter of debate. The stress state and depression and anxiety symptoms may affect the basal activity of the HPA axis in MMT patients. However, the effect of psychological factors on HPA activity was not simultaneously controlled in previous studies. This study investigated differences in HPA basal activity between MMT patients and controls using psychological variables as covariates. The participants included 52 MMT patients and 41 age-matched, non-heroin-dependent controls. Psychological states were self-reported with the Perceived Stress Scale, Self-Rating Depression Scale and Self-Rating Anxiety Scale. The hair cortisol level was adopted as a biomarker of HPA basal activity and was determined with liquid chromatography tandem mass spectrometry. The results revealed that MMT patients had significantly higher hair cortisol levels than the controls (p<0.05), but the difference was not significant (p>0.05) when the perceived stress, depression and anxiety scores were used as covariates. We concluded that patients with long-term MMT showed higher basal activity of the HPA axis. The high chronic stress state and increase in depression and anxiety symptoms may mask the suppression effect of methadone on the HPA activity. PMID:27010803

  19. Mercury contamination in fish and human hair from Hainan Island, South China Sea: Implication for human exposure.

    PubMed

    Liu, Jin-Ling; Xu, Xiang-Rong; Yu, Shen; Cheng, Hefa; Peng, Jia-Xi; Hong, Yi-Guo; Feng, Xin-Bin

    2014-11-01

    Hair has long been recognized as a good biomarker for human exposure to Hg. The mercury concentrations in 14 species of marine fish and hair samples from 177 coastal residents in Hainan, South China Sea were investigated to assess the status of mercury exposure associated with marine fish consumption. Concentrations of total Hg (THg) and methylmercury (MeHg) in the fish muscles were 0.094 ± 0.008 and 0.066 ± 0.006 μg/gww, respectively, which were far below the limit considered safe for consumption (0.5 μg/g). The average THg concentrations in hair of adults (1.02 ± 0.92 μg/g) were lower than the provisional tolerable weekly intake (PTWI) level of 2.2 μg/g. However, 23.7% of children had a hair THg level exceeding the RfD level of 1μg/g, indicating a great risk of Hg exposure to children via fish consumption. The concentration of THg in hair was significantly correlated with fish consumption but not with gender-specific fish intake. With higher fish consumption frequency, the fishermen had significantly elevated hair Hg levels compared to the students and the other general public, who had similar hair THg levels but different fish consumption patterns, indicating the existence of other sources of Hg exposure to the residents of Hainan Island. PMID:25262073

  20. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    SciTech Connect

    Dasari, Sameera; Yuan, Yukun

    2009-11-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20-200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca{sup 2+}]{sub e} or application of the GABA{sub A} receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.

  1. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    PubMed Central

    Dasari, Sameera; Yuan, Yukun

    2009-01-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20 - 200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca2+]e or application of the GABAA receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect. PMID:19664649

  2. Recent evidence from epidemiological studies on methylmercury toxicity.

    PubMed

    Murata, Katsuyuki; Yoshida, Minoru; Sakamoto, Mineshi; Iwai-Shimada, Miyuki; Yaginuma-Sakurai, Kozue; Tatsuta, Nozomi; Iwata, Toyoto; Karita, Kanae; Nakai, Kunihiko

    2011-09-01

    More than fifty years have passed since the outbreak of Minamata disease, and large-scale methylmercury poisoning due to industrial effluents or methylmercury-containing fungicide intoxication has scarcely happened in developed countries. On the other hand, widespread environmental mercury contamination has occurred in gold and mercury mining areas of developing countries. In this article, we provided an overview of recent studies addressing human health effects of methylmercury, which we searched using the PubMed of the US National Library of Medicine. The following suggestions were obtained for low-level methylmercury exposure: (1) In recent years, the proportion of human studies addressing methylmercury has tended to decrease. (2) Prenatal exposure to methylmercury through fish intake, even at low levels, adversely affects child development after adjusting for polychlorinated biphenyls and maternal fish intake during pregnancy, whereas maternal seafood intake has some benefits. (3) Long-term methylmercury exposure through consumption of fish such as bigeye tuna and swordfish may pose a potential risk of cardiac events involving sympathovagal imbalance. (4) In measuring methylmercury levels in preserved umbilical cord collected from inhabitants born in Minamata areas between 1945 and 1989, the elevated concentrations (≥1 mg/g) were observed mainly in inhabitants born between 1947 and 1968, and the peak coincided with the peak of acetaldehyde production in Minamata. (5) Since some developing countries appear to be in similar situations to Japan in the past, attention should be directed toward early recognition of a risky agent and precautions should be taken against it. PMID:21996768

  3. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction.

    PubMed

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz

    2006-11-01

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 mug g(-1) and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. PMID:16896613

  4. Methylmercury concentrations in broiler's meat and hen's meat and eggs

    SciTech Connect

    Kambamanoli-Dimou, A. ); Kilikidis, S.; Kamarianos, A. )

    1989-05-01

    The concentration of mercury in food has been considered to present the greatest toxicological danger to the average citizen. The presence of mercury in foods has been reported in several studies. Much of the research has been carried out on total mercury concentration in foods and not on methylmercury concentration and as it is known methylmercury is the most dangerous form of mercury. Methylmercury, which is highly resistant to biodegradation, can be synthesized from any other form of mercury in the aquatic biosphere, can be bioconcentrated in the aquatic food chain and through fish-meals can be transported and concentrated in animals and their products. Such food chains, together with the various terrestrial food chains would represent a serious risk for man. This study was undertaken to determine the methylmercury levels in broiler's meat, hen's meat and eggs.

  5. Methylmercury in populations eating large quantities of marine fish

    SciTech Connect

    Turner, M.D.; Marsh, D.O.; Smith, J.C.; Inglis, J.B.; Clarkson, T.W.; Rubio, C.E.; Chiriboga, J.; Chiriboga, C.C.

    1980-11-01

    A Peruvian population was identified that was chronically exposed to methylmercury from the longterm consumption of ocean fish. The weekly fish intake averaged 10.1 kg per average family of 6.2 persons. Blood methylmercury concentrations ranged from 11 to 275 ng/ml, with a mean of 82 ng/ml. Paresthesias were reported by 29.5% of the population. In contrast, a nearby control population had a mean weekly fish consumption of 1.9 kg per average family of 6.4 persons. Their blood methylmercury levels were 3.3-25.1 ng/ml, with a mean of 9.9 ng/ml. Paresthesias were reported by 49.5% of this control group. No individual was identified with symptoms or signs that could be attributed to methylmercury intoxication.

  6. FISH CONSUMPTION, METHYLMERCURY, AND HUMAN HEART DISEASE.

    SciTech Connect

    LIPFERT, F.W.; SULLIVAN, T.M.

    2005-09-21

    Environmental mercury continues to be of concern to public health advocates, both in the U.S. and abroad, and new research continues to be published. A recent analysis of potential health benefits of reduced mercury emissions has opened a new area of public health concern: adverse effects on the cardiovascular system, which could account for the bulk of the potential economic benefits. The authors were careful to include caveats about the uncertainties of such impacts, but they cited only a fraction of the applicable health effects literature. That literature includes studies of the potentially harmful ingredient (methylmercury, MeHg) in fish, as well as of a beneficial ingredient, omega-3 fatty acids or ''fish oils''. The U.S. Food and Drug Administration (FDA) recently certified that some of these fat compounds that are primarily found in fish ''may be beneficial in reducing coronary heart disease''. This paper briefly summarizes and categorizes the extensive literature on both adverse and beneficial links between fish consumption and cardiovascular health, which are typically based on studies of selected groups of individuals (cohorts). Such studies tend to comprise the ''gold standard'' of epidemiology, but cohorts tend to exhibit a great deal of variability, in part because of the limited numbers of individuals involved and in part because of interactions with other dietary and lifestyle considerations. Note that eating fish will involve exposure to both the beneficial effects of fatty acids and the potentially harmful effects of contaminants like Hg or PCBs, all of which depend on the type of fish but tend to be correlated within a population. As a group, the cohort studies show that eating fish tends to reduce mortality, especially due to heart disease, for consumption rates up to about twice weekly, above which the benefits tend to level off. A Finnish cohort study showed increased mortality risks in the highest fish-consuming group ({approx}3 times

  7. High Runx1 levels promote a reversible more differentiated cell-state in hair follicle stem cells during quiescence

    PubMed Central

    Lee, Song Eun; Sada, Aiko; Zhang, Meng; McDermitt, David J.; Lu, Shu Yang; Kemphues, Kenneth J.; Tumbar, Tudorita

    2014-01-01

    Quiescent hair follicle (HF) bulge stem cells (SCs) differentiate to early progenitor (EP) hair germ (HG) cells, which divide to produce transit-amplifying (TA) matrix cells. EPs can revert to SCs upon injury, but whether this de-differentiation occurs in normal HF homeostasis (hair cycle), and the mechanisms regulating both differentiation and de-differentiation are unclear. Here we use lineage tracing, gain of function, transcriptional profiling, and functional assays to examine the role of observed endogenous Runx1 level changes in the hair cycle. We find that forced Runx1 expression induces hair degeneration (catagen) and simultaneously promotes changes in the quiescent bulge SC transcriptome towards a cell-state resembling the EP HG fate. This cell-state transition is functionally reversible. We propose that SC differentiation and de-differentiation are likely to occur during normal HF degeneration and niche restructuring in response to changes in endogenous Runx1 levels associated with SC location with respect to the niche. PMID:24462289

  8. Effect of low-level laser treatment on cochlea hair-cell recovery after ototoxic hearing loss

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; He, Peijie; Jung, Jae Yun; Ahn, Jin-Chul; Chung, Phil-Sang; Lee, Min Young; Suh, Myung-Whan

    2013-12-01

    The primary cause of hearing loss includes damage to cochlear hair cells. Low-level laser therapy (LLLT) has become a popular treatment for damaged nervous systems. Based on the idea that cochlea hair cells and neural cells are from same developmental origin, the effect of LLLT on hearing loss in animal models is evaluated. Hearing loss animal models were established, and the animals were irradiated by 830-nm diode laser once a day for 10 days. Power density of the laser treatment was 900 mW/cm2, and the fluence was 162 to 194 J. The tympanic membrane was evaluated after LLLT. Thresholds of auditory brainstem responses were evaluated before treatment, after gentamicin, and after 10 days of LLLT. Quantitative scanning electron microscopic (SEM) observations were done by counting remaining hair cells. Tympanic membranes were intact at the end of the experiment. No adverse tissue reaction was found. On SEM images, LLLT significantly increased the number of hair cells in middle and basal turns. Hearing was significantly improved by laser irradiation. After LLLT treatment, both the hearing threshold and hair-cell count significantly improved.

  9. Short communication: A low-cost method for analyzing nevirapine levels in hair as a marker of adherence in resource-limited settings.

    PubMed

    Gandhi, Monica; Yang, Qiyun; Bacchetti, Peter; Huang, Yong

    2014-01-01

    The measurement of antiretroviral concentrations in hair is emerging as an important technology to objectively quantify adherence to combination antiretroviral therapy. Hair levels of antiretrovirals are the strongest independent predictor of virologic success in large prospective cohorts of HIV-infected patients and surpass self-report in predicting outcomes. Hair is easy to collect and store, but validated methods to analyze antiretroviral levels in hair using liquid chromatography tandem mass spectrometry (LC-MS/MS) are expensive. We report here on the development of a thin-layer chromatography (TLC) assay for the semiquantitative analysis of nevirapine in hair. TLC assay results from 11 samples were consistent with results using LC-MS/MS [Spearman correlation coefficient 0.99 (95% CI 0.95-0.996)]. This simple, low-cost method of analyzing nevirapine concentrations in hair may provide a novel monitoring tool for antiretroviral adherence in resource-limited settings and merits further study in clinical settings. PMID:24164410

  10. Mercury levels in the Carson River and effect of group VI anions on methylmercury production in sediments

    SciTech Connect

    Bonzongo, J.C.; Chen, Y.; Miller, G.C.

    1995-12-31

    Distribution and speciation of Hg were determined in a fluvial-lacustrine system impacted by Hg-contaminated mine wastes. Levels of total-Hg (THg), introduced into the river by contaminated particles eroded from mine tailings, were found to be controlled by the water flow regimes and varying from background concentrations of {approximately}2 ng L{sup -1} to values in the ppb range in the contaminated section. Concentrations of MeHg were higher in surface waters of both the contaminated river section (>7 ng Hg L{sup -1}) and the reservoir (11 to 4 ng Hg L{sup -1}), than in the seasonally anoxic bottom waters of the reservoir (<1 ng Hg L{sup -1}). The Carson River flows in to the and basin of eastern California and western Nevada, where the rivers are essentially Ca-Na-HCO{sub 3} waters with the terminal lakes being Na-Cl-CO{sub 3} waters. Due to the evapoconcentration of water as it flows downstream in this and environment, levels of naturally occurring oxyanion-forming elements (such as Mo, W, Se,{hor_ellipsis}) known to influence sulfate reduction, are high for noncontaminated freshwaters, exhibiting their highest values in terminal basins. In contrast, MeHg/THg ratios decreased significantly with the increase downstream of oxyanion-forming element concentrations. Experimental results of Hg methylation conducted with sediments showed that combined to alkaline pH (>7.4) and high levels of inorganic Hg, the production of MeHg in the studied aquatic system, mainly by sulfate reducing bacteria, could be negatively affected by some group VI anions, since they could interfere in metabolic processes involving both phosphate and sulfate.

  11. Low-level exposure to methylmercury modifies muscarinic cholinergic receptor binding characteristics in rat brain and lymphocytes: physiologic implications and new opportunities in biologic monitoring.

    PubMed Central

    Coccini, T; Randine, G; Candura, S M; Nappi, R E; Prockop, L D; Manzo, L

    2000-01-01

    Methylmercury (MeHg) affects several parameters of cholinergic function. These alterations are thought to play a role in MeHg neurotoxicity. In vitro experiments have indicated that MeHg acts as a strong competitive inhibitor of radioligand binding to muscarinic cholinergic receptors (mAChRs) in rat brain. Furthermore, rat brain mAChRs share several pharmacologic characteristics of similar receptors present on lymphocytes. Using the muscarinic antagonist [(3)H]quinuclidinyl benzilate (QNB) to label receptors, we investigated the in vivo interactions of MeHg with rat brain mAChRs. We also investigated whether MeHg-induced central mAChR changes are reflected by similar alterations in splenic lymphocytes. Exposure to low doses of MeHg--0.5 or 2 mg/kg/day in drinking water--for 16 days significantly increased (20-44% of control) mAChRs density (B(max)) in the hippocampus and cerebellum without affecting receptor affinity (K(d)). The effect of MeHg did not occur immediately; it was not apparent until 2 weeks after the termination of treatment. No significant changes in [(3)H]QNB binding were observed in the cerebral cortex. In splenic lymphocytes, mAChR density was remarkably increased (95-198% of control) by day 14 of MeHg exposure and remained enhanced 14 days after the cessation of treatment. These results suggest up-regulation of mAChRs in selected brain regions (hippocampus and cerebellum) after prolonged low-level ingestion of MeHg in rats. These cerebral effects are delayed in onset and are preceded by a marked increase in density of mAChRs on lymphocytes. In chronic MeHg exposure, peripheral lymphocytes may represent a sensitive target for the interaction of MeHg with mAChRs and, therefore, may be predictive indicators of later adaptive response involving cerebral mAChRs. Additionally, the effect of MeHg on lymphocyte mAChRs in vivo indicates that this receptor system should be investigated further as a possible target for MeHg immunotoxicity. Images Figure 1

  12. Hair Care

    MedlinePlus

    ... Body Looking and feeling your best Hair care Hair care Short, long, curly, straight, up, down. Hair options can seem endless! Not all of what makes your hair look good comes from the outside, though. Good ...

  13. Oily hair

    MedlinePlus

    Hair - oily ... are some tips for preventing and treating oily hair: Shampoo your hair every day. Leaving the shampoo on your head ... minutes before rinsing may help. Avoid brushing your hair too often or too vigorously, since the brushing ...

  14. Hair Transplants

    MedlinePlus

    ... How to Choose the Best Skin Care Products Hair Transplants What are hair transplants? In punch transplanting, a plug containing hair ... What should first be done before considering a hair transplant? Before the procedure, an ASDS doctor will ...

  15. Buprenorphine and nor-buprenorphine levels in head hair samples from former heroin users under Suboxone® treatment.

    PubMed

    Belivanis, Stamatis; Tzatzarakis, Manolis N; Vakonaki, Elena; Kovatsi, Leda; Mantsi, Mary; Alegakis, Athanasios; Kavvalakis, Matthaios P; Vynias, Dionisios; Tsatsakis, Aristidis M

    2014-06-01

    In the current study, buprenorphine (BUP) and its major metabolite, nor-buprenorphine (NBUP), were determined in hair samples from former heroin users following Suboxone® treatment. Hair samples from 36 subjects were analyzed. The drugs of interest were isolated from hair by solid-liquid extraction with methanol and were determined by liquid chromatography-mass spectrometry, using an electrospray ionization interface. The analytical parameters of the method (such as linearity, limits of quantification, recovery, accuracy, and precision) were determined. The inter-quartile range of BUP levels was from 11.4 to 37.4 pg/mg (mean value 56.6 pg/mg) for the proximal hair segment, from 5.8 to 43.3 pg/mg for the middle hair segment (mean value 25.3 pg/mg), while a range from 4.3 to 33.9 pg/mg (mean value 105.2 pg/mg) for the distant to the root hair segment was determined. For NBUP the corresponding inter-quartile range was from 27.0 to 147.6 for the proximal segment (mean value 95.4 pg/mg), from 21.5 to 164.7 pg/mg for the middle segment (mean value 102.0 pg/mg) and from 20.4 to 103.6 pg/mg for the distant segment (mean value 156.8 pg/mg). The mean BUP/NBUP concentration ratio was 0.5. The daily dose of Suboxone® correlated significantly with BUP and NBUP levels in hair (p = 0.001 and p = 0.023) as well as with the BUP/NBUP ratio (p = 0.010). No significant correlation was found between the levels of BUP and NBUP and the duration of Suboxone® administration. The developed and validated method was successfully used for the determination of BUP and NBUP in hair samples collected from former heroin users under Suboxone® treatment. PMID:24817054

  16. Effect of low level laser therapy on hair cell regeneration following gentamicin induced ototoxicity in postnatal organotypic culture of rat cochlea

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Kim, Young Hoon; Kim, Se Hyung; He, Peijie; Ahn, Jin Chul

    2010-02-01

    Aim: To investigate effects of low level laser therapy (LLLT) on hair cell regeneration following gentamicin ototoxicity in organotypic culture of rat cochlea. Methods: Organotypic cultures of cochlea in culture medium were allowed to grow for 17 days (C group). The organotypic cultures were irradiated daily with 808 nm LD laser, at 28.8 J/ cm2(L group). The organotypic culture were exposed to 1 mM of gentamicin for 48 hr and allowed to recover (G group) or allowed to recover in the culture medium with daily LLLT at 28.8 J/ cm2 (GL group) for 17 days. The cochleae were stained with FM1-43. The number of hair cells was counted in each group serially for 17 days. Results: While the C group kept on losing hair cells in vitro culture, the hair cells remained rather stationary in the L group. The number of hair cells revealed significantly larger number of hair cells in the L group compared to the C group (p=0.05). And the group × time interaction was also significant (p=0.04). That is, the number of hair cells in the C group showed decreasing tendency which was significantly different from the L group. In G group, the initial number of hair cells decreased to 37.2% of that of the gentamicin non-exposed groups. While the G group kept on losing hair cells, the number of hair cells increased in the GL group. The number of hair cells revealed significantly larger in the GL group (p=0.01) compared to G group. And the group × time interaction was also significant (p=0.01). Also, the number of hair cells in the GL group showed increasing tendency which was significantly different from the G group. Conclusion: These results suggest that LLLT promotes hair cell regeneration following gentamicin damage in cochlear explants.

  17. Hair cortisol levels track phylogenetic and age related differences in hypothalamic-pituitary-adrenal (HPA) axis activity in non-human primates.

    PubMed

    Fourie, Nicolaas H; Bernstein, Robin M

    2011-11-01

    Hair has been shown to archive a uniquely time averaged signal of endocrine activity, and holds attractive advantages for both laboratory and field research. Prior research has explored the potential of hair hormone analysis to examine hormone-behavior relationships. To date, no research has focused on the potential of the technique to investigate age-related changes or taxon differences in endocrine function. It is known that non-human primate infants of many taxa exhibit high cortisol levels after parturition, which rapidly decline with age. It has also been shown that hypercortisolism generally characterizes platyrrhine (New World monkey) endocrine function. These endocrine trends have been characterized using cortisol levels determined from serum, plasma, and feces. Here we test whether cortisol levels determined from hair recover similar phylogenetic and age related patterns in endocrine function in non-human primates. In order to test whether hair cortisol reflect infant hypercortisolism with significant age-related decline, hair cortisol levels are measured in samples from wild vervet monkeys (Chlorocebus aethiops) and captive Guinea baboons (Papio hamadryas papio), ranging in age from infants through juveniles. Further, in order to test whether platyrrhines exhibit significantly higher hair cortisol levels compared to strepsirrhines and catarrhines, and therefore faithfully recover similar signals as more traditionally used substrates (e.g. serum), hair cortisol levels are quantified in adult female hair samples collected from a broad range of non-human primate taxa. Results confirm that hair cortisol levels accurately reflect known phylogenetic and age related patterns of circulating cortisol levels. Therefore, these results suggest that hair may be an ideal hormone bearing substrate for research focused on the examination of population endocrine profiles, cross-sectional studies of endocrine function and taxon variation in hormone levels, as well as

  18. Country-specific estimates of the incidence of intellectual disability associated with prenatal exposure to methylmercury.

    PubMed

    Bellinger, David C; O'Leary, Keri; Rainis, Holly; Gibb, Herman J

    2016-05-01

    This paper describes country-specific estimates of the incidence of intellectual disability in children associated with prenatal exposure to methylmercury. A systematic review was undertaken to identify country-specific data on hair mercury concentrations in women of reproductive age. A variety of approaches were used to estimate biomarker concentrations for countries lacking such data. A dose-effect relationship derived on the basis of the data from three large prospective studies relating prenatal methylmercury exposure to IQ in children was used to estimate the country-specific incidences of mild, moderate, severe, and profound intellectual disability in children as a result of prenatal methylmercury exposure. The incidence of methylmercury-associated mild intellectual disability (IQ scores 50-70) varied nearly 40-fold across countries, with the greatest incidences generally in countries that are islands or that are coastal. Countries with high birth rates and greater consumption of foods that contribute most to methylmercury intake in humans (seafood, rice) can be expected to make the largest contributions to the worldwide burden of disease associated with methylmercury. The assumptions and limitations of the estimates are discussed. PMID:26874048

  19. [Total mercury in hair samples of inhabitants of Tapajós River, Pará State, Brazil].

    PubMed

    Pinheiro, M C; Guimarães, G A; Nakanishi, J; Oikawa, T; Vieira, J L; Quaresma, M; Cardoso, B; Amoras, W

    2000-01-01

    This study evaluates human exposure to methylmercury in fishermen and their families in four villages on the Tapajós river: Rainha, Barreiras, São Luís do Tapajós and Paraná-Mirim. Hair analyses were performed with atomic absorption spectophotometry. Total hair mercury levels varied between 2.9mg/g and 71.5mg/g. Paraná-Mirim showed the lowest level. The highest level was found in São Luís do Tapajós and Barreiras. The hair mercury was six to seven times higher than the established safe limit of 10mg/g. No statistically significant difference was found between the mean level of total mercury taken from the inhabitants living downstream and upstream in Itaituba village (p > 0.05). These results confirm that human exposure to methylmercury is occurring on the Tapajós river and suggest that continued fish ingestion in that region is a potential risk factor for the appearance of symptoms and signs of Minamata disease. An immediate epidemiological survey program is recommended. PMID:10881131

  20. Human hair lead copper levels in three occupationally unexposed population groups in Calcutta

    SciTech Connect

    Sen, J.; Chaudhuri, A.B.D.

    1996-10-01

    The element lead (Pb) has been very widely studied in man due to its widespread occurrence and toxic effects. There is no known nutritional value of Pb and it is stored in the bone by replacing calcium. In the cellular level, Pb alters cell membrane structure and membrane on function. It is a potent inhibitor of the Na{sup +} K{sup +} ATPase. Pb also interferes with the activity of the enzymes delta-aminoevulinic acid synthetase, delta-aminolevulinic dehydrase and intra-mitochondrial ferrochelatase. In the pre-natal level, Pb-exposure may lead to an increased risk of prematurity and reduction of gestational age in humans. Pb-exposure causes adverse neuro-psychological effects among young children and numerous endrocrinal disturbances among adults. It has shown that Human Scalp Hair (HSH) Pb concentration can be used very successfully to document population exposure to this toxic element. Copper is known to be biologically essential, but Cu poisoning is rare in humans. This study attempts to document exposure and to determine `base-line` values for HSH Pb and CU among three occupationally unexposed population groups in Calcutta. 15 refs., 1 tab.

  1. Interpretation of group-level factors from a large population dataset in the determination of ethyl glucuronide in hair.

    PubMed

    Salomone, Alberto; Pirro, Valentina; Lombardo, Tonia; Di Corcia, Daniele; Pellegrino, Sergio; Vincenti, Marco

    2015-05-01

    Ethyl glucuronide in hair (HEtG) is the most accredited marker to prove chronic alcohol abuse. In this study, we evaluate the comprehensive results of HEtG determination obtained during four years of activity (2009-2013) in our laboratory (Northwestern Italy) - across a large cohort of subjects (over 20 000 subjects mostly undergoing medical examination for driving re-licensing) - to provide a general perspective on HEtG analysis and dependence on group-level factors (e.g. age, gender, site and period of hair collection) that could bias the analytical results. HEtG was measured by liquid chromatography-tandem mass spectrometry. About 12% of the subjects presented HEtG concentrations over 30 pg/mg. Upon non-parametric hypothesis tests, distributions of HEtG in independent populations categorized by age proved statistically different, while no differences were found by considering gender, BMI, and site of sampling (head vs. chest hair). A 'seasonality' factor was evaluated by comparing periods of collection approximately representing the hair growth in winter, spring, summer and autumn, and a seasonal trend was observed showing the highest HEtG levels in winter (16.7%) and minimum levels in summer (8.3%). The experimental HEtG distributions confirm that chest hair sampling can be trusted as an alternative to scalp. Furthermore, among biological and external factors, age and season of sampling may significantly influence the measured HEtG concentration, and this potential source of bias should be taken into account when the results are interpreted. PMID:25065354

  2. Hair Mercury Levels in U.S. Children and Women of Childbearing Age: Reference Range Data from NHANES 1999–2000

    PubMed Central

    McDowell, Margaret A.; Dillon, Charles F.; Osterloh, John; Bolger, P. Michael; Pellizzari, Edo; Fernando, Reshan; de Oca, Ruben Montes; Schober, Susan E.; Sinks, Thomas; Jones, Robert L.; Mahaffey, Kathryn R.

    2004-01-01

    Exposure to methyl mercury, a risk factor for neurodevelopmental toxicity, was assessed in U.S. children 1–5 years of age (n = 838) and women 16–49 years of age (n = 1,726) using hair mercury analysis during the 1999–2000 National Health and Nutrition Examination Survey (NHANES). The data are nationally representative and are based on analysis of cross-sectional data for the non-institutionalized, U.S. household population. The survey consisted of interviews conducted in participants’ homes and standardized health examinations conducted in mobile examination centers. Distributions of total hair mercury levels expressed as micrograms per gram hair Hg and the association of hair Hg levels with sociodemographic characteristics and fish consumption are reported. Geometric mean (standard error of the geometric mean) hair mercury was 0.12 μg/g (0.01 μg/g) in children, and 0.20 μg/g (0.02 μg/g) in women. Among frequent fish consumers, geometric mean hair mercury levels were 3-fold higher for women (0.38 vs. 0.11 μg/g) and 2-fold higher for children (0.16 vs. 0.08 μg/g) compared with nonconsumers. The NHANES 1999–2000 data provide population-based data on hair mercury concentrations for women and children in the United States. Hair mercury levels were associated with age and fish consumption frequency. PMID:15289161

  3. The use of low-level light therapy in the treatment of androgenetic alopecia and female pattern hair loss.

    PubMed

    Gupta, Aditya K; Daigle, Deanne

    2014-04-01

    Androgenetic alopecia (AGA) or female pattern hair loss (FPHL) is the most common form of hair loss in men and women. Despite its common occurrence, our understanding of the etiology of AGA and FPHL remains incomplete. As such, traditional therapies demonstrate modest efficacies and new therapies continue to be sought. Low-level light therapy (LLLT) is a relatively new technique used to promote hair growth in both men and women with AGA and FPHL. Currently, there exist several LLLT devices marketed for the treatment of alopecia, which claim to stimulate hair growth; yet marketing these devices only requires that safety, not efficacy, be established. A handful of studies have since investigated the efficacy of LLLT for alopecia with mixed results. These studies suffered from power, confounding and analysis issues which resulted in a high risk of bias in LLLT studies. Due to the paucity of well-conducted randomized controlled trials, the efficacy of LLLT devices remains unclear. Randomized controlled trials of LLLT conducted and reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement would greatly increase the credibility of the evidence and clarify the ambiguity of the effectiveness of LLLT in the treatment of AGA and FPHL. PMID:23924031

  4. Quantitative analysis of the endogenous GHB level in the hair of the Chinese population using GC/MS/MS.

    PubMed

    Shi, Yan; Cui, Xiaopei; Shen, Min; Xiang, Ping

    2016-04-01

    Endogenous production complicates interpretation when gamma-hydroxybutyrate (GHB) is measured in hair for forensic purposes. A method capable of quantifying the endogenous concentration of GHB in human head hair was developed and validated using GC/MS/MS. Hair was digested under alkaline conditions (1 mol/L NaOH, 90 °C 10 min), and GHB-d6 was used as an internal standard. Before derivatization with BSTFA and ethyl acetate, a liquid-liquid extraction with ethyl acetate under acidic conditions was performed. GHB-TMS derivatives were detected using GC/MS/MS in the multiple-reaction monitoring mode. This method exhibited good linearity (y = 0.018x + 0.038, R(2) = 0.9998), and the limit of detection was 0.02 ng/mg. The extraction recoveries were more than 60%, and the inter-day and intra-day relative standard deviations (RSD) were less than 15%. This method has been applied for the analysis of the endogenous GHB in hair samples from 66 drug-free Chinese donors. The mean measured concentration for 0-3 cm hair was 1.93 ± 1.40 ng/mg (n = 66), and extreme values were in the range of 0.28-4.91 ng/mg. The mean male endogenous GHB level was 2.95 ng/mg (0.92-4.91 ng/mg, n = 35), while the mean female level was 0.77 ng/mg (0.28-1.95 ng/mg, n = 31). This method was applied to a forensic case for the determination of GHB in hair samples but it is hard to make a reasonable "cut off" in hair. The solution is to use each subject as his own control. PMID:26807994

  5. GLIA AND METHYLMERCURY NEUROTOXICITY

    PubMed Central

    Ni, Mingwei; Li, Xin; Rocha, João B. T.; Farina, Marcelo; Aschner, Michael

    2014-01-01

    Methylmercury (MeHg) is a global environmental pollutant with significant adverse effects on human health. As the major target of MeHg, the central nervous system (CNS) exhibits the most recognizable poisoning symptoms. The role of the two major nonneuronal cell types, astrocytes and microglia, in response to MeHg exposure was recently compared. These two cell types share several common features in MeHg toxicity, but interestingly, these cells types also exhibit distinct response kinetics, indicating a cell-specific role in mediating MeHg-induced neurotoxicity. The aim of this study was to review the most recent literature and summarize key features of glial responses to this organometal. PMID:22852858

  6. Methylmercury risk assessment issues

    SciTech Connect

    Lipfert, F.W.; Saroff, L.

    1996-07-01

    This paper reviews the general background of health risks associated with mercury (Hg), primarily methylmercury (MeHg), with a view towards application to advanced technologies that could reduce any contributions from coal combustion. The need for accurate assessment of such risks is discussed, since Hg is now widely dispersed in the environment and cannot easily be eliminated. The primary pathway of MeHg intake is through eating contaminated fish. The issues of concern include identification of critical health outcomes (various neurological indices) and their confounding factors, accurate assessment of MeHg intake rates, and appropriate use of dose-response functions. Ultimately, such information will be used to evaluate alternative coal combustion systems.

  7. Determination of arsenic and mercury level in scalp hair from a selected population in Penang, Malaysia using XRF technique

    NASA Astrophysics Data System (ADS)

    Aldroobi, Khalid Saleh Ali; Shukri, A.; Bauk, Sabar; Munem, Eid Mahmoud Abdel; Abuarra, Ali. M. A.

    2013-10-01

    As with many cities all over the world with active industrial developments, the city of Penang in Malaysia has also the potential of being exposed to industrial pollution. Such exposure would certainly have a detrimental impact on the environment and the people. The determination of trace elemental levels in hair which is well known as a method for environmental exposure monitoring, evaluation of heavy metal poisoning, assessment of nutrient levels and disease diagnoses. In this study, it is selected as the method to determine the possible exposure to pollutants in the form of unwanted trace elements. The natural levels of trace elements in hair are hence monitored first as reference values for the assessment of the possible human contamination levels. In this work the concentrations of As and Hg in the human scalp hair of 100 residents of Penang were determined using XRF. The results of this study are compared with the results obtained in other cities where such measurements have also been carried out.

  8. Effect of low-level laser treatment on cochlea hair-cell recovery after acute acoustic trauma

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Bahk, Chan Woong; Kim, Se Hyung; Ahn, Jin-Chul; Jung, Jae Yun; Chung, Phil-Sang; Suh, Myung-Whan

    2012-06-01

    We investigated the effect of low-level laser radiation on rescuing hair cells of the cochlea after acute acoustic trauma and hearing loss. Nine rats were exposed to noise. Starting the following day, the left ears (NL ears) of the rats were irradiated at an energy output of 100 to 165 mW/cm2 for 60 min for 12 days in a row. The right ears (N ears) were considered as the control group. Frequency-specific hearing levels were measured before the noise exposure and also after the 1st, 3rd to 5th, 8th to 10th and 12th irradiations. After the 12th treatment, hair cells were observed using a scanning electron microscope. Compared to initial hearing levels at all frequencies, thresholds increased markedly after noise exposure. After the 12th irradiation, hearing threshold was significantly lower for the NL ears compared to the N ears. When observed using an electron microscope, the number of hair cells in the middle turn of the NL ears was significantly larger than that of the N ears. Our findings suggest that low-level laser irradiation promotes recovery of hearing thresholds after acute acoustic trauma.

  9. Methylmercury Concentration in Fish and Risk-Benefit Assessment of Fish Intake among Pregnant versus Infertile Women in Taiwan.

    PubMed

    Hsi, Hsing-Cheng; Hsu, You-Wen; Chang, Tien-Chin; Chien, Ling-Chu

    2016-01-01

    This study examined methylmercury (MeHg) concentrations in fish, the daily MeHg exposure dose, and the risk-benefit of MeHg, ω-3 polyunsaturated fatty acid (ω-3 PUFA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) related to fish intake among pregnant and infertile women in Taiwan. The measured MeHg concentrations in fish did not exceed the Codex guideline level of 1 mg/kg. Swordfish (0.28 ± 0.23 mg/kg) and tuna (0.14 ± 0.13 mg/kg) had the highest MeHg concentrations. The MeHg concentration in the hair of infertile women (1.82 ± 0.14 mg/kg) was significantly greater than that of pregnant women (1.24 ± 0.18 mg/kg). In addition, 80% of infertile women and 68% of pregnant women had MeHg concentrations in hair that exceeded the USEPA reference dose (1 mg/kg). The MeHg concentrations in hair were significantly and positively correlated with the estimated daily MeHg exposure dose. Based on the risk-benefit evaluation results, this paper recommends consumption of fish species with a low MeHg concentration and high concentrations of DHA + EPA and ω-3 PUFA (e.g., salmon, mackerel, and greater amberjack). PMID:27187161

  10. Methylmercury Concentration in Fish and Risk-Benefit Assessment of Fish Intake among Pregnant versus Infertile Women in Taiwan

    PubMed Central

    Hsi, Hsing-Cheng; Hsu, You-Wen; Chang, Tien-Chin; Chien, Ling-Chu

    2016-01-01

    This study examined methylmercury (MeHg) concentrations in fish, the daily MeHg exposure dose, and the risk–benefit of MeHg, ω-3 polyunsaturated fatty acid (ω-3 PUFA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) related to fish intake among pregnant and infertile women in Taiwan. The measured MeHg concentrations in fish did not exceed the Codex guideline level of 1 mg/kg. Swordfish (0.28 ± 0.23 mg/kg) and tuna (0.14 ± 0.13 mg/kg) had the highest MeHg concentrations. The MeHg concentration in the hair of infertile women (1.82 ± 0.14 mg/kg) was significantly greater than that of pregnant women (1.24 ± 0.18 mg/kg). In addition, 80% of infertile women and 68% of pregnant women had MeHg concentrations in hair that exceeded the USEPA reference dose (1 mg/kg). The MeHg concentrations in hair were significantly and positively correlated with the estimated daily MeHg exposure dose. Based on the risk–benefit evaluation results, this paper recommends consumption of fish species with a low MeHg concentration and high concentrations of DHA + EPA and ω-3 PUFA (e.g., salmon, mackerel, and greater amberjack). PMID:27187161

  11. Hair Removal

    MedlinePlus

    ... maintain a steady temperature by providing some insulation. Terminal hair is coarser, darker, and longer than vellus ... hair that grows on your head. Around puberty, terminal hair starts to grow in the armpits and ...

  12. Hair transplant

    MedlinePlus

    Hair restoration ... MR, Keene SA, Stough DB, Rogers NE. Hair restoration. In: Bolognia JL, Jorizzo JL, Schaffer JV, eds. ... Elsevier Saunders; 2012:chap 157. Fisher J. Hair restoration. In: Neligan PC, ed. Plastic Surgery . 3rd ed. ...

  13. Dry hair

    MedlinePlus

    Some causes of dry hair are: Anorexia nervosa Excessive hair washing, or using harsh soaps or alcohols Excessive blow-drying Dry air Menkes kinky hair syndrome Malnutrition Underactive parathyroid ( ...

  14. Hair loss

    MedlinePlus

    ... that is applied to the scalp to stimulate hair growth. Other medicines, such as hormones, may be prescribed to decrease hair loss and promote hair growth. Drugs such as finasteride and dutasteride can be ...

  15. Neurological and neurocognitive functions from intrauterine methylmercury exposure.

    PubMed

    Yorifuji, Takashi; Kado, Yoko; Diez, Midory Higa; Kishikawa, Toshihiro; Sanada, Satoshi

    2016-05-01

    In the 1950s, large-scale food poisoning caused by methylmercury was identified in Minamata, Japan. Although severe intrauterine exposure cases (ie, congenital Minamata disease patients) are well known, possible impacts of methylmercury exposure in utero among residents, which is likely at lower levels than in congenital Minamata disease patients, are rarely explored. In 2014, the authors examined neurological and neurocognitive functions among 18 exposed participants in Minamata, focusing on fine motor, visuospatial construction, and executive functions. More than half of the participants had some fine motor and coordination difficulties. In addition, several participants had lower performance for neurocognitive function tests (the Rey-Osterrieth Complex Figure test and Keio version of the Wisconsin card sorting test). These deficits imply diffuse brain damage. This study suggests possible neurological and neurocognitive impacts of prenatal exposure to methylmercury among exposed residents of Minamata. PMID:26267674

  16. The Chemical Forms of Mercury in Human Hair: A Study using X-ray Absorption Spectroscopy

    PubMed Central

    George, Graham N.; Singh, Satya P.; Myers, Gary J.; Watson, Gene E.; Pickering, Ingrid J.

    2013-01-01

    Human hair is frequently used as a bio-indicator of mercury exposure. We have used X-ray absorption spectroscopy to examine the chemical forms of mercury in human hair samples taken from individuals with high fish consumption and concomitant exposure to methylmercury. The mercury is found to be predominantly methylmercury cysteine or closely related species, comprising approximately 80% of the total mercury with the remainder an inorganic thiolate-coordinated mercuric species. No appreciable role was found for selenium in coordinating mercury in hair. PMID:20225071

  17. Preconceptional monitoring of mercury levels in hair and blood as a tool for minimizing associated reproductive risks.

    PubMed

    Neuman, Gal; Gareri, Joey; Koren, Gideon

    2014-12-01

    We describe the case of a 41-year-old woman, planning a pregnancy, who had a spontaneous abortion and subsequently was found to have high blood mercury levels. The source of high mercury was in her diet that contained fish as her main source of protein. Serial measurements of mercury in hair and blood allowed the team to determine the exact time when safe levels of mercury were reached, to eliminate elevated mercury levels as a potential cause of spontaneous abortion and to use preconception counseling to minimize the risk for adverse pregnancy outcome. PMID:24831651

  18. Hair Dye and Hair Relaxers

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers Share Tweet Linkedin Pin it More sharing ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

  19. Improved chronic fatigue symptoms after removal of mercury in patient with increased mercury concentration in hair toxic mineral assay: a case.

    PubMed

    Shin, Sae-Ron; Han, A-Lum

    2012-09-01

    Clinical manifestations of chronic exposure to organic mercury usually have a gradual onset. As the primary target is the nervous system, chronic mercury exposure can cause symptoms such as fatigue, weakness, headache, and poor recall and concentration. In severe cases chronic exposure leads to intellectual deterioration and neurologic abnormality. Recent outbreaks of bovine spongiform encephalopathy and pathogenic avian influenza have increased fish consumption in Korea. Methyl-mercury, a type of organic mercury, is present in higher than normal ranges in the general Korean population. When we examine a patient with chronic fatigue, we assess his/her methyl-mercury concentrations in the body if environmental exposure such as excessive fish consumption is suspected. In the current case, we learned the patient had consumed many slices of raw tuna and was initially diagnosed with chronic fatigue syndrome. Therefore, we suspected that he was exposured to methyl-mercury and that the mercury concentration in his hair would be below the poisoning level identified by World Health Organization but above the normal range according to hair toxic mineral assay. Our patient's toxic chronic fatigue symptoms improved after he was given mercury removal therapy, indicating that he was correctly diagnosed with chronic exposure to organic mercury. PMID:23115707

  20. Mercury levels assessment in hair of riverside inhabitants of the Tapajós River, Pará State, Amazon, Brazil: fish consumption as a possible route of exposure.

    PubMed

    Faial, Kleber; Deus, Ricardo; Deus, Simonny; Neves, Ramiro; Jesus, Iracina; Santos, Elisabeth; Alves, Cláudio Nahum; Brasil, Davi

    2015-04-01

    The study present evaluated the levels of mercury (Hg) and methylmercury (MeHg) in hair samples of people from Barreiras community, riverside inhabitants of the Tapajós River (Pará, Brazil), an area impacted by clandestine gold mining, as well as we analyzed the levels of Hg and Se (selenium) in nine fish species (carnivores and non-carnivorous) from the Tapajós River, which stand out as the main species consumed by riverside inhabitants, to evaluate a relationship between frequency of fish consumption and Hg concentration, and also to evaluate possible mechanisms of fish protection (or non-protection) to Hg exposure by Se. Furthermore we analyze the water quality to evaluate the environmental trophic state, fact responsible by creating conditions that can potentiate the effects of toxic mercury. Concentrations of Hg and MeHg were analyzed in hair samples of 141 volunteers in different age band. Of those, 84.40% of samples present values above the threshold for biological tolerance, which is 6.00μgg(-1) of total Hg in hair. Total Hg, in men there was a variation of 2.07-24.93μgg(-1), while for women the variation was 4.84-27.02μgg(-1). Consequently, the level of MeHg in men presented a variation of 1.49-19.57μgg(-1), with an average of 11.68μgg(-1), while with women the variation was from 3.73 to 22.35μgg(-1), with an average of 10.38μgg(-1). In fish species, Hg concentrations in carnivorous species had an average of 0.66μgg(-1), higher than that permitted by current legislation, ranging from 0.30 to 0.98μgg(-1), while the non-carnivorous species have values below the recommended by the legislation averaging 0.09μgg(-1), ranging between 0.02 and 0.44μgg(-1). For Se in fish, show that among carnivores, the contents of Se ranged between 0.18 and 0.54μgg(-1) with a mean of 0.34μgg(-1), while for non-carnivores these values were of the order of 0.16-0.56μgg(-1), with an average of 0.32μgg(-1). In surface water quality variables at the sampling points

  1. Hair transplantation.

    PubMed

    Avram, Marc R

    2012-12-01

    Hair transplantation is a purely dermatologic surgical procedure that dermatologists should be able to perform in appropriate candidates with hair loss. Hair transplantation techniques performed in the 1960s through the 1990s utilized large grafts that created an unfortunate public image of unnatural-appearing transplanted hair. Over the last 15 years, hair transplantation has been performed using follicular units to create consistently natural-looking transplanted hair in both men and women. This article provides an overview of candidate selection and state-of-the-art techniques for performing hair transplantation. PMID:23409484

  2. Mercury hair levels and factors that influence exposure for residents of Huancavelica, Peru.

    PubMed

    Hagan, Nicole; Robins, Nicholas; Hsu-Kim, Heileen; Halabi, Susan; Espinoza Gonzales, Ruben Dario; Ecos, Enrique; Richter, Daniel; Vandenberg, John

    2015-06-01

    Between 1564 and 1810, nearly 17,000 metric tons of mercury (Hg) vapor was released to the environment during cinnabar refining in the small town of Huancavelica, Peru. The present study characterizes individual exposure to mercury using total and speciated Hg from residential samples, total Hg in hair, and self-reported questionnaire data regarding factors influencing exposure (e.g., frequency of fish consumption, occupation). Total Hg concentrations in hair from 118 participants ranged from 0.10 to 3.6 µg/g, similar to concentrations found in the USA and lower than concentrations in other Hg-exposed populations around the world. Pearson's correlation coefficients for data in this study suggest that there is a positive correlation between concentrations of total Hg in hair and concentrations of total Hg in adobe bricks, dirt floors, and surface dust; however, these correlations are not statistically significant. Results of a one-way analysis of variance (ANOVA) identified that total Hg concentrations in hair were significantly related to gender (p < 0.001), living in a neighborhood where smelters were previously located (p = 0.021), smoking status (p = 0.003), frequency of house cleaning (p = 0.019), and frequency of fish consumption (p = 0.046). These results highlight the need for further studies to better characterize Hg exposure in Huancavelica, particularly as related to residential contamination. A comprehensive analysis of residential Hg contamination and exposure in Huancavelica will guide the development and implementation of mitigation and remediation strategies in the community to reduce potential health risks from residential Hg exposure. PMID:25467206

  3. Screening heavy metals levels in hair of sanitation workers by X-ray fluorescence analysis.

    PubMed

    Md Khudzari, Jauharah; Wagiran, Husin; Hossain, I; Ibrahim, Noorddin

    2013-01-01

    This work presents a study of human hair as a bio-indicator for detection of heavy metals as part of environmental health surveillance programs project to develop a subject of interest in the biomedical and environmental sciences. A total of 34 hair samples were analyzed that consisting of 29 samples from sanitation workers and five samples from students. The hair samples were prepared and treated in accordance to the International Atomic Energy Agency (IAEA) recommendations. The concentrations of heavy metals were analyzed using the energy dispersive X-ray fluorescence (EDXRF) technique by X-50 Mobile X-ray Fluorescence (XRF) at Oceanography Institute, Universiti Malaysia Terengganu. The performance of EDXRF analyzer was tested by Standard Reference Material (SRM 2711) Montana Soil which was in good agreement with certified value within 14% deviations except for Hg. While seven heavy metals: Mn, Fe, Ni, Cu, Zn, Se, and Sb were detected in both groups, three additional elements, i.e. As, Hg and Pb, were detected only in sanitation workers group. For sanitation workers group, the mean concentration of six elements, Mn, Fe, Cu, Zn, Se, and Sb, shows elevated concentration as compared to the control samples concentration. Results from both groups were compared and discussed in relation to their respective heavy metals concentrations. PMID:22846873

  4. Differences in mortality among bobwhite fed methylmercury chloride dissolved in various carriers

    USGS Publications Warehouse

    Spann, J.W.; Heinz, G.H.; Camardese, M.B.; Hill, E.F.; Moore, J.F.; Murray, H.C.

    1986-01-01

    Twelve-day-old bobwhite chicks were fed a diet containing 0, 5.4 or 20 ppm methylmercury chloride. The methylmercury chloride was added to the diet either in a dry, pulverized form or dissolved in acetone, propylene glycol or corn oil. Mortality was measured for 6 weeks, and samples of liver were saved for mercury analysis. Mortality was significantly lower in birds fed 20 ppm methylmercury chloride when acetone was the solvent. The reduced mortality could not be explained by effects of acetone on dietary level of mercury or on uptake of mercury into the body.

  5. [Microcosm Simulation Study and Methylmercury Forming Mechanism at Landscape Water of City].

    PubMed

    Liu, Xiao-hong; Si, You-bin; Guo, Zi-wei; Du, Cheng-zhu; Zhu, Cong-cong

    2016-04-15

    Mercury is harmful to the environment, which has gradually become one of the research hotspots. Sediments, as a main repository of pollutants, have an important impact on water quality and the internal organisms, which deserves our research. In this paper, we focused on Hefei landscape water sediment and tried to investigate the status of inorganic mercury and methylmercury pollutions in the sediment. To study the conversion process from inorganic mercury to methylmercury and their enrichment levels and mechanism, we established the ecological chain of "sediment-water-grass-fish" through analog microcosm examination. The results were as follows: from ten water and sediment samples in Hefei landscape water sediment, we found that the contents of inorganic mercury and methylmercury ranged 11.74-13.12 µg · kg⁻¹ and 0.37-2.23 µg · kg⁻¹, respectively. The microcosm examination showed that: with increasing culture time, inorganic mercury in sediments gradually decreased. There was a phenomenon that the content of methylmercury increased at first and then decreased to reach the balance later. Both the inorganic mercury and methylmercury in water change showed an increasing trend. The enrichment contents of inorganic mercury in Egeria densa Planch, and golden mandarin fish (Siniperca scherzeri Steindachner) were low while their enrichment of methylmercury could he great. In addition, we found that both the bioaccumulation ability and the enrichment coefficient of methylmercury in the body of golden mandarin fish were the maximum during the same period. PMID:27548953

  6. Mercury in women exposed to methylmercury through fish consumption, and in their newborn babies and breast milk

    SciTech Connect

    Skerfving, S.

    1988-10-01

    The presence of methylmercury in fish is a major environmental problem. During the major epidemics of methylmercury poisoning through sea food in Minamata in Japan, and through dressed seed in Iraq, there was a high prevalence of infants, who developed cerebral palsy. This was generally assumed to be due to intrauterine methylmercury poisoning, as it is well known, that methylmercury is transferred through the placenta into the fetus. There is also a possibility that exposure occurred through breast milk, as high levels of mercury in breast milk have been reported in mothers from Minamata. Information on the relationship between methylmercury exposure, mercury levels in blood of mothers and their babies, and levels in breast milk are reported here.

  7. Temporal Assessment of Methylmercury in an Endangered Pacific Seabird (Invited)

    NASA Astrophysics Data System (ADS)

    Vo, A. E.; Bank, M. S.; Shine, J. P.; Edwards, S. V.

    2010-12-01

    Methylmercury cycling in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists over the extent to which mercury accumulation in biota may have resulted from increases in anthropogenic output over time. To address this, we assessed historical and recent mercury exposure in an endangered Pacific seabird, the Black-footed Albatross (Phoebastria nigripes), using feather samples from museum specimens spanning the past 130 years. We additionally analyzed stable isotopes of nitrogen (δ15N) and carbon (δ13C) to control for confounding factors of temporal change in trophic structure or diet. As a long-lived, wide-ranging, top marine predator and an endangered, keystone species in the North Pacific, the Black-footed Albatross comprises an ideal sentinel species for determining the effect of both global increases in mercury throughout the previous century and regional increases during the recent past on bioaccumulation and risk among avian wildlife. A significantly higher proportion of post-1940 samples contained above deleterious threshold levels (~40,000 ng/g) of methylmercury relative to pre-1940 samples, and mean concentrations were significantly higher in post-1990 than in pre-1990 samples. We also found increasingly higher amounts of (presumably curator-mediated) inorganic mercury contamination in older museum samples for the Black-footed Albatross as well as two non-pelagic comparison species, which informs future studies on bioaccumulation in museum specimens to analyze methylmercury rather than total mercury in all but recently collected specimens. Although complementary stable isotope data suggested no historic change in albatross trophic level, there was a significant change in δ13C signature over time. However, after controlling for these potential confounders, time significantly and positively associated with methylmercury exposure. Changes in methylmercury levels

  8. Biomagnifications of mercury and methylmercury in tuna and mackerel.

    PubMed

    Hajeb, P; Jinap, S; Ahmad, I

    2010-12-01

    Seawater may be contaminated by harmful substances, including toxic elements released by human activities. The present study evaluates the total mercury and methylmercury concentrations and their correlations to fish body size in longtail tuna and short-bodied mackerel from Chendring, Kuantan, at east coast and Kuala Perlis at west costs of Peninsular Malaysia during May to November 2007. Total mercury and methylmercury in muscle tissue of 69 samples of longtail tuna and short-bodied mackerel, ranged from 0.180 to 1.460 μg/g and 0.0.169-0.973 μg/g and 0.251-1.470 μg/g and 0.202-1.352, whereas the methylmercury to total mercury ratio ranged from 70% to 83%, respectively. Samples of both species from the east coast showed higher levels of mercury compared to those from west coast. In all of the locations, significant positive correlations were found between fish body weight and mercury content (R(2) > 0.470). The estimated weekly intake of total mercury and methylmercury from the consumption 66.33 g/week of short-bodied mackerel and 18.34 g/week of longtail tuna (based on local dietry survey) was found to be lower than the maximum limit of 5 and 1.5 μg/kg bodyweight established by FAO/WHO and codex, respectively. PMID:20041345

  9. Study to determine the possible hazard of methylmercury in seafood to the fetus in utero. Final report, 1980-1985

    SciTech Connect

    Marsh, D.O.; Turner, M.D.; Smith, J.C.

    1985-12-01

    This study was conducted to determine the possible hazards of methylmercury (MeHg) in seafood to the fetus in utero. Hair and blood samples of pregnant women in New Bedford, MA, Manta, Ecuador, and Mancora, Peru (all areas of high seafood consumption) were examined. These samples were collected and studied at various stages of gestation and during pre- and post-natal periods. In some cases, blood and hair samples of some of the infants born to these women were also examined. The women of Manta and Mancora showed higher levels of MeHg than the women in New Bedford. However, no health hazards could be linked to any of the infants from the ingestion of MeHg in marine fish. Although no human data exist, experimental evidence suggests marine fish may contain elements that reduce the toxicity of MeHg and it's possible that selenium contributes to the protective effect of fish vs. grain diets. Tables of MeHg levels in the study groups are attached to the report.

  10. Monitoring metals in the population living in the vicinity of a hazardous waste incinerator: levels in hair of school children.

    PubMed

    Nadal, Martí; Bocio, Ana; Schuhmacher, Marta; Domingo, Jose L

    2005-06-01

    Hair samples of 134 school children (12-14 yr old) living in three residential zones in the vicinity of a new hazardous waste incinerator (HWI) (Constanti, Tarragona County, Catalonia, Spain) were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) for arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), and vanadium (V) concentrations. These concentrations were compared with those obtained in a baseline survey performed in the same area during the period of construction of the HWI. Current mean concentrations ranged from values under the respective limit of detection (As, Be, Cd, Tl, and V) to 0.70 and 0.86 microg/g for Hg and Pb, respectively. In comparison to the baseline survey, the levels of Cr, Mn, Ni, Pb, and Sn showed a significant reduction, whereas Hg concentrations were similar. No significant differences were observed according to the sex of the children. However, some differences were noted, especially for Pb and Cr, with respect to the specific zone of residence. In general terms, the current metal levels in hair of school children are similar or even lower than those recently reported for a number of industrial and residential areas of various regions and countries. PMID:15930590

  11. S-Mercuration of ubiquitin carboxyl-terminal hydrolase L1 through Cys152 by methylmercury causes inhibition of its catalytic activity and reduction of monoubiquitin levels in SH-SY5Y cells.

    PubMed

    Toyama, Takashi; Abiko, Yumi; Katayama, Yuko; Kaji, Toshiyuki; Kumagai, Yoshito

    2015-01-01

    Methylmercury (MeHg) is an environmental electrophile that covalently modifies cellular proteins. In this study, we identified proteins that undergo S-mercuration by MeHg. By combining two-dimensional SDS-PAGE, atomic absorption spectrometry and ultra performance liquid chromatography mass spectrometry (UPLC/MS/MS), we revealed that ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is a target for S-mercuration in human neuroblastoma SH-SY5Y cells exposed to MeHg (1 µM, 9 hr). The modification site of UCH-L1 by MeHg was Cys152, as determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. MeHg was shown to inhibit the catalytic activity of recombinant human UCH-L1 in a concentration-dependent manner. Knockdown of UCH-L1 indicated that this enzyme plays a critical role in regulating mono-ubiquitin (monoUb) levels in SH-SY5Y cells and exposure of SH-SY5Y cells to MeHg caused a reduction in the level of monoUb in these cells. These observations suggest that UCH-L1 readily undergoes S-mercuration by MeHg through Cys152 and this covalent modification inhibits UCH-L1, leading to the potential disruption of the maintenance of cellular monoUb levels. PMID:26558469

  12. Flame Hair

    PubMed Central

    Miteva, Mariya; Tosti, Antonella

    2015-01-01

    Background ‘Flame hairs’ is a trichoscopic feature described as hair residue from pulling anagen hairs in trichotillomania. Objective: To detect whether flame hairs are present in other hair loss disorders. Methods We retrospectively, independently and blindly reviewed the trichoscopic images of 454 consecutive patients with alopecia areata (99 cases), trichotillomania (n = 20), acute chemotherapy-induced alopecia (n = 6), acute radiotherapy-induced alopecia (n = 2), tinea capitis (n = 13), lichen planopilaris (n = 33), frontal fibrosing alopecia (n = 60), discoid lupus erythematosus (n = 30), dissecting cellulitis (n = 11), central centrifugal cicatricial alopecia (n = 94) and traction alopecia (n = 86) for the presence of flame hairs. We prospectively obtained trichoscopy-guided scalp biopsies from flame hairs in trichotillomania, alopecia areata, traction alopecia and central centrifugal cicatricial alopecia (1 case each). Results Flame hairs were detected in 100% of the acute chemotherapy- and radiotherapy-induced alopecias, where they were the predominant hair abnormality. They were also found in trichotillomania (55%), alopecia areata (21%), traction alopecia (4%) and central centrifugal cicatricial alopecia (3%). On pathology, they corresponded to distorted hair shafts. Conclusion The flame hair is a type of broken hair which can be seen in various hair loss disorders. It results from traumatic pulling of anagen hairs or from anagen arrest due to inflammation or drugs. © 2015 S. Karger AG, Basel PMID:27171360

  13. Hair Changes

    MedlinePlus

    ... To get rid of unwanted hair growth: Tweeze, wax or shave, which are all safe during pregnancy. ... To get rid of unwanted hair growth: Tweeze, wax or shave, which are all safe during pregnancy. ...

  14. Hair Loss

    MedlinePlus

    ... may cause hair loss in women. If your hair loss has occurred gradually with advancing age, FOLLICULAR DEGENERATION may be the cause. Post-pregnancy hormone changes usually reverse themselves without any treatment. While follicular degeneration cannot ...

  15. Hair Loss

    MedlinePlus

    ... Common baldness" usually means male-pattern baldness, or permanent-pattern baldness. It is also called androgenetic alopecia. ... will grow back normally. However, scarring can cause permanent hair loss. Hot oil hair treatments or chemicals ...

  16. Hair Loss

    MedlinePlus

    ... are stress, a low protein diet, a family history, or poor nutrition. Treatment for hair loss depends on the cause. In some cases, treating the underlying cause will correct the problem. Other treatments include medicines and hair restoration.

  17. Hair loss

    MedlinePlus

    ... continual hair pulling or scalp rubbing Radiation therapy Tinea capitis (ringworm of the scalp) Tumor of the ovary or ... a plucked hair Skin biopsy If you have ringworm on the scalp, you may be prescribed an ...

  18. The levels of zinc and molybdenum in hair and food grain in areas of high and low incidence of esophageal cancer: a comparative study.

    PubMed

    Ray, S S; Das, D; Ghosh, T; Ghosh, A K

    2012-07-01

    The outcome of different studies on the role of Zn & Mo in esophageal cancer (EC) is conflicting. Here, the levels of those elements in hair as well as food grain of two different ethnic populations across two continents have been studied to explore their role in EC. Two different ethnic populations are taken from (i) Eastern Cape, South Africa (RSA), an area of very high incidence of EC and (ii) West Bengal, India, an area of low incidence of that disease. Each ethnic population is divided into two groups: case and control (n=30 for all groups). Hair samples from all groups and food grain from RSA and India are analyzed for Zn & Mo content. This study shows a strong correlation between reduced levels of those elements in hair and the development of EC in RSA (both Zn &Mo: p < 0.0001), though it is only suggestive in Indian context (both Zn & Mo p ? 0.05). Interestingly, control group of RSA shows significantly reduced level of those elements in hair even with respect to Indian case group (Zn: p<0.001 & Mo: p< 0.00001). Food grain from RSA has significantly reduced level of those elements with respect to India (both Zn & Mo: p <0.0001). This deficiency of Zn & Mo in food grains can be correlated to the deficiency of those elements in hair of RSA population. The deficiency of Zn & Mo can be correlated to the development of EC. PMID:22980353

  19. Your Hair

    MedlinePlus

    ... someone's hair, the less melanin there is. A person with brown or black hair has much more melanin than someone with ... example, many blondes have light skin, whereas many people with darker skin have dark brown or black hair. And don't forget genes (genes are ...

  20. Neurobehavioral effects of developmental methylmercury exposure.

    PubMed Central

    Gilbert, S G; Grant-Webster, K S

    1995-01-01

    Methylmercury (MeHg) is a global environmental problem and is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the world's environment. Human exposure to MeHg primarily occurs through the consumption of contaminated food such as fish, although catastrophic exposures due to industrial pollution have occurred. The fetus is particularly sensitive to MeHg exposure and adverse effects on infant development have been associated with levels of exposure that result in few, if any, signs of maternal clinical illness or toxicity. High levels of prenatal exposure in humans result in neurobehavioral effects such as cerebral palsy and severe mental retardation. Prenatal exposure to MeHg in communities with chronic low-level exposure is related to decreased birthweight and early sensorimotor dysfunction such as delayed onset of walking. Neurobehavioral alterations have also been documented in studies with nonhuman primates and rodents. Available information on the developmental neurotoxic effects of MeHg, particularly the neurobehavioral effects, indicates that the fetus and infant are more sensitive to adverse effects of MeHg. It is therefore recommended that pregnant women and women of childbearing age be strongly advised to limit their exposure to potential sources of MeHg. Based on results from human and animal studies on the developmental neurotoxic effects of methylmercury, the accepted reference dose should be lowered to 0.025 to 0.06 MeHg microgram/kg/day. Continued research on the neurotoxic effects associated with low level developmental exposure is needed. PMID:8549462

  1. Neurobehavioral effects of developmental methylmercury exposure

    SciTech Connect

    Gilbert, S.G.; Grant-Webster, K.S.

    1995-09-01

    Methylmercury (MeHg) is a global environmental problem and is listed by the International Program of Chemical Safety as one of the six most dangerous chemicals in the world`s environment. Human exposure to MeHg primarily occurs through the consumption of contaminated food such as fish, although catastrophic exposures due to industrial pollution have occurred. The fetus is particularly sensitive to MeHg exposure and adverse effects on infant development have been associated with levels of exposure that result in few, if any, signs of maternal clinical illness or toxicity. High levels of prenatal exposure in humans result in neurobehavioral effects such as cerebral palsy and severe mental retardation. Prenatal exposure to MeHg in communities with chronic low-level exposure is related to decreased birthweight and early sensorimotor dysfunction such as delayed onset of walking. Neurobehavioral alterations have also been documented in studies with non human primates and rodents. Available information on the developmental neurotoxic effects of MeHg, particularly the neurobehavioral effects, indicates that the fetus and infant are more sensitive to adverse effects of MEHg. It is therefore recommended that pregnant women and women of childbearing age be strongly advised to limit their exposure to potential sources of MeHg. Based on results from human and animal studies on the developmental neurotoxic effects of methylmercury, the accepted reference dose should be lowered to 0.025 to 0.06 MeHg {mu}g/kg/day. Continued research on the neurotoxic effects associated with low level developmental exposure is needed. 107 refs., 3 tabs.

  2. Eggshell thickness in mallards fed methylmercury

    SciTech Connect

    Heinz, G.H.

    1980-09-01

    Eggshell thinning has been linked to impaired reproduction in many wild birds. Previous work of my own and others led me to believe that methylmercury may cause some eggshell thinning in birds. The present study was designed to determine whether methylmercury in the diet of mallards would thin their eggshells and whether it would add to eggshell thinning caused by DDE.

  3. [Methylmercury: existing recommendations; methods of analysing and interpreting the results; economic evaluation].

    PubMed

    González-Estecha, Montserrat; Bodas-Pinedo, Andrés; Martínez-García, María José; Trasobares-Iglesias, Elena M; Bermejo-Barrera, Pilar; Ordóñez-Iriarte, José María; Llorente-Ballesteros, María Teresa; Prieto-Menchero, Santiago; Guillén-Pérez, José Jesús; Martell-Claros, Nieves; Cuadrado-Cenzual, María Ángeles; Rubio-Herrera, Miguel Ángel; Martínez-Álvarez, Jesús Román; Calvo-Manuel, Elpidio; Farré-Rovira, Rosaura; Herráiz-Martínez, Miguel Ángel; Bretón Lesmes, Irene; García-Donaire, José Antonio; Sáinz-Martín, María; Martínez-Astorquiza, Txantón; Gallardo-Pino, Carmen; Moreno-Rojas, Rafael; Salas-Salvadó, Jordi; Blanco Fuentes, María; Arroyo-Fernández, Manuel; Calle Pascual, Alfonso

    2015-01-01

    The beneficial effects of fish consumption are well- known. Nevertheless, there is worldwide concern regard methylmercury concentrations in fish, which is why many countries such as the United States, Australia, New Zealand, Canada and numerous European countries have made fish consumption recommendations for their populations, particularly vulnerable groups, in order to México methylmercury intake. Blood and hair are the best biological samples for measuring methylmercury. The most widely-used method to analyse methylmercury is cold vapor atomic absorption spectrometry, although there are also direct methods based on the thermal decomposition of the sample. In recent years, the number of laboratories that measure mercury by inductively coupled plasma mass spectrometry has increased. In addition, the different kinds of mercury can be distinguished by coupling chromatography methods of separation. Laboratories that analyse mercury in biological samples need to participate in external quality control programmes. Even if mercury emissions are reduced, mercury may remain in the environment for many years, so dietary recommendations are fundamental in order to reduce exposure. It is necessary to propose public health measures aimed at decreasing mercury exposure and to evaluate the benefits of such measures from the economic and social standpoints. PMID:25561094

  4. Monitoring of mercury pollution in Tanzania: relation between head hair mercury and health.

    PubMed

    Harada, M; Nakachi, S; Cheu, T; Hamada, H; Ono, Y; Tsuda, T; Yanagida, K; Kizaki, T; Ohno, H

    1999-03-01

    Through 1996 into 1997, a spot investigation on mercury contamination was conducted three times in Tanzania, especially around the Lake Victoria. A total of 150 goldminers, 103 fishermen and their families, and 19 residents of Mwanza City volunteered for the current study. A high total mercury level of 48.3 ppm (near to 50 ppm, a critical level of Minamata disease) and over in the head hair was observed in six goldminers (highest value, 953 ppm), four fishermen and their families (highest value, 416 ppm), and four Mwanza people (highest value, 474 ppm). With the exception of these 14 subjects, however, each mean total mercury level was well within the normal range (below 10 ppm). Out of the goldminers examined, 14 cases were diagnosed as a mild form of inorganic-mercury poisoning according to their clinical symptoms (such as polyneuropathy mercurialis, neuroasthemia, or tremor mercurialis) and the low ratio of methylmercury to total mercury, whereas neither inorganic-mercury poisoning nor methylmercury poisoning (Minamata disease) was noted in the fishermen and their families or in the Mwanza people. In addition, some subjects who showed a high total mercury level made habitual use of toilet soap containing much mercury. The findings obtained suggest that the mercury pollution in Tanzania is not very serious, however, it should be observed continuously. PMID:10231987

  5. [REGIONAL INDICES OF TRACE ELEMENT LEVELS IN HAIR IN CHLILDREN OF THE POPULATION OF THE IRKUTSK REGION].

    PubMed

    Lisetskaya, L G; Efimova, N V

    2016-01-01

    747 hair samples of the pre-school aged children from different regions of the Irkutsk Region have been analyzed with the aim to establish the regional reference indices. The measurements were performed by the atomic-absorption method. The population deficiency of the essential microelements of zinc, copper along with the simultaneous excess of magnesium, mercury was revealed to be observed at the territory of the Irkutsk Region. According to the results of the study of mercury level in biological medias of the children population of the Irkutsk region it is possible to mark the unfavorable areas where chronic anthropogenic load has led to the accumulation of mercury in the body. PMID:27266027

  6. Neonatal hair nicotine levels and fetal exposure to paternal smoking at home.

    PubMed

    Seong, Moon-Woo; Hwang, Jong Hee; Moon, Jin Soo; Ryu, Hye-Jung; Kong, Sun-Young; Um, Tae Hyun; Park, Jae-Gahb; Lee, Do-Hoon

    2008-11-15

    Exposure to environmental tobacco smoke (ETS) is a major risk to human health, and the home is the greatest single source of ETS for children. The authors investigated fetal exposure to paternal smoking at home during pregnancy. Korean families were included as trios of fathers, mothers, and neonates identified in 2005-2007. Sixty-three trios were finally enrolled in this study after exclusion of those in which the mother was a smoker or was regularly exposed to ETS at places other than the home. Nicotine and cotinine concentrations in hair were measured by using liquid chromatography-tandem mass spectrometry to determine long-term exposure to ETS. The difference between neonatal nicotine concentrations in the smoker and nonsmoker groups was not statistically significant. However, in the indoor-smoker group, neonatal nicotine concentrations were significantly higher than in the outdoor and nonsmoker groups (P < 0.05). Furthermore, neonatal nicotine concentrations in the outdoor-smoker group were not different from those in the nonsmoker group. These findings indicate that paternal smoking inside the home leads to significant fetal and maternal exposure to ETS and may subsequently affect fetal health. Conversely, findings show that paternal smoking outside the home prevents the mother and her fetus from being exposed to ETS. PMID:18801888

  7. Phytoremediation of ionic and methylmercury pollution

    SciTech Connect

    Meagher, Richard B

    2010-04-28

    Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and sequester the toxic elemental pollutants, like the heavy metal mercury. Our current working hypothesis is that transgenic plants controlling the transport, chemical speciation, electrochemical state. volatilization, and aboveground binding of mercury will: a) tolerate mercury and grow rapidly in mercury contaminated environments; b) prevent methylmercury from entering the food chain; c) remove mercury from polluted soil and . water; and d) hyperaccumulate mercury in aboveground tissues for later harvest. Progress toward these specific aims is reported: to increase the transport of mercury into roots and to aboveground vegetative organs; to increase biochemical sinks and storage for mercury in leaves; to increase leaf cell vacuolar storage of mercury; and to demonstrate that several stacked transgenes, when functioning in concert, enhance mercury resistance and hyperaccumulation to high levels.

  8. Accumulation of brominated flame retardants and polychlorinated biphenyls in human breast milk and scalp hair from the Philippines: levels, distribution and profiles.

    PubMed

    Malarvannan, Govindan; Isobe, Tomohiko; Covaci, Adrian; Prudente, Maricar; Tanabe, Shinsuke

    2013-01-01

    Paired human breast milk and scalp hair samples (n=30) were obtained in 2008 from primipara and multipara mothers living in two locations in the Philippines viz., Payatas, a waste dumpsite, and Malate, a non-dumpsite. Samples were analyzed for three groups of organohalogenated compounds, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). PCBs were the predominantly identified compounds (median: 70 ng/g lipid wt.) in all the breast milk samples. In the human milk, CB-153 was the most dominant PCB congener (17-44% contribution to the sum PCB), closely followed by CB-138 (12-35%), CB-118 (4-12%), CB-180 (2-13%), CB-187 (3-13%), and CB-170 (1.5-10%). Levels of PBDEs (median: 3.0 ng/g lipid wt.) in human milk samples from the Philippines were similar to other Asian or European countries. BDE-47, -99, -100 and -153 were the major PBDE congeners. For HBCDs, the α-isomer was predominant followed by the γ-HBCD isomer in the both locations. PBDE levels in human milk were significantly higher in the dumpsite (3.9 ng/g lipid wt.) than in the non-dump site (2.2 ng/g lipid wt.). PBDE concentrations (including BDE-209) were significantly higher (median: 70 ng/g hair) than those of PCBs (median: 30 ng/g hair) and HBCDs (median: 1.0 ng/g hair) in all the scalp hair samples. To our knowledge, this is the first report on HBCDs in human scalp hair. PBDE congeners in scalp hair were dominated by BDE-209 and BDE-47. On a congener basis, the levels of PBDEs found in scalp hair were higher than those in Spain (children and adults) and China (general people). PCB levels found in scalp hair were higher than those in Greece, Romania and Belgium, but lower than those in China. In this study, there were no significant differences in the concentration of PCBs and HBCDs in human milk; and PCBs, HBCDs and PBDEs in human scalp hair from the two different locations. No significant correlations were observed between PCBs, PBDEs and

  9. Hair mercury and urinary cadmium levels in Belgian children and their mothers within the framework of the COPHES/DEMOCOPHES projects.

    PubMed

    Pirard, Catherine; Koppen, Gudrun; De Cremer, Koen; Van Overmeire, Ilse; Govarts, Eva; Dewolf, Marie-Christine; Van De Mieroop, Els; Aerts, Dominique; Biot, Pierre; Casteleyn, Ludwine; Kolossa-Gehring, Marike; Schwedler, Gerda; Angerer, Jürgen; Koch, Holger M; Schindler, Birgit K; Castaño, Argelia; Esteban, Marta; Schoeters, Greet; Den Hond, Elly; Sepai, Ovnair; Exley, Karen; Horvat, Milena; Bloemen, Louis; Knudsen, Lisbeth E; Joas, Reinhard; Joas, Anke; Van Loco, Joris; Charlier, Corinne

    2014-02-15

    A harmonized human biomonitoring pilot study was set up within the frame of the European projects DEMOCOPHES and COPHES. In 17 European countries, biomarkers of some environmental pollutants, including urinary cadmium and hair mercury, were measured in children and their mothers in order to obtain European-wide comparison values on these chemicals. The Belgian participant population consisted in 129 school children (6-11 years) and their mothers (≤ 45 years) living in urban or rural areas of Belgium. The geometric mean levels for mercury in hair were 0.383 μg/g and 0.204 μg/g for respectively mothers and children. Cadmium in mother's and children's urine was detected at a geometric mean concentration of respectively 0.21 and 0.04 μg/l. For both biomarkers, levels measured in the mothers and their child were correlated. While the urinary cadmium levels increased with age, no trend was found for hair mercury content, except the fact that mothers hold higher levels than children. The hair mercury content increased significantly with the number of dental amalgam fillings, explaining partially the higher levels in the mothers by their higher presence rate of these amalgams compared to children. Fish or seafood consumption was the other main parameter determining the mercury levels in hair. No relationship was found between smoking status and cadmium or mercury levels, but the studied population included very few smokers. Urinary cadmium levels were higher in both mothers and children living in urban areas, while for mercury this difference was only significant for children. Our small population showed urinary cadmium and hair mercury levels lower than the health based guidelines suggested by the WHO or the JECFA (Joint FAO/WHO Expert Committee on Food Additives). Only 1% had cadmium level slightly higher than the German HBM-I value (1 μg/l for adults), and 9% exceeded the 1 μg mercury/g hair suggested by the US EPA. PMID:24333995

  10. Clinical and epidemiological aspects of methylmercury poisoning.

    PubMed Central

    Bakir, F.; Rustam, H.; Tikriti, S.; Al-Damluji, S. F.; Shihristani, H.

    1980-01-01

    An opportunity to study the effects of methylmercury poisoning in humans was provided by the large outbreak in Iraq in 1971-2. In adults, poisoning resulted from the ingestion of home-made bread prepared from methylmercury-treated seed grain and there was a highly significant correlation between the amount of bread ingested and blood mercury levels. Poisoning in infants resulted either from prior exposure in utero or from suckling or both. Blood mercury levels were higher in infants and children than in adults. There was no increased incidence of congenital defects. Symptoms and signs of poisoning and histopathological changes were mainly confined to the CNS. Symptoms developed, on average, 1-2 months after exposure. In children there was mental retardation with delayed onset of speech and impaired motor, sensory and autonomic function. Severely affected children were blind and deaf. In adults, the clinical picture could be classified as 1, mild (mainly of sensory symptoms) 2, moderate (sensory symptoms accompanied by cerebellar signs) and 3, severe (gross ataxia with marked visual and hearing loss which, in some cases, progressed to akinetic mutism followed by coma). Grades 1 and 2 carried a better prognosis thant grade 3. Interference with transmission at the myoneural junction was found in 14% of patients studied. There was no evidence of peripheral nerve involvement per se and sensory symptoms may be of central origin. The clinical differences between the Iraqi and Japanese outbreaks may be a result, in part at least, of the severe, prolonged and continuous exposure which occurred in the latter outbreak. Improvement was observed among the mild and moderate group. Treatment with chelating agents, thiol resin, haemodialysis and exchange transfusion lowered blood mercury concentrations but produced no convincing clinical benefit. To be effective, treatment may need to be instituted soon after exposure. PMID:7383945

  11. Variation in the Levels of Aluminum and Manganese in Scalp Hair Samples of the Patients Having Different Psychiatric Disorders with Related to Healthy Subjects.

    PubMed

    Arain, Mariam S; Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Atif; Naeemullah; Ali, Jamshed; Arain, Salma Aslam; Panhwar, Abdul Haleem

    2015-11-01

    There is very limited information available on the role of trace elements in psychiatric disorders (PSD). Immense pieces of evidence support the idea that exposure to trace and toxic metals, such as aluminum (Al) and manganese (Mn), may be factors or cofactors in the etiopathogenesis of a variety of psychiatric disorders. The aim of our study was to assess the Al and Mn in scalp hair samples of 102 patients having different types of psychiatric disorder PSD diseases together with 120 referent subjects of male patients in the age group of 45-60 years. The understudy elements in scalp hair samples were assessed by the flame atomic absorption spectrophotometry after microwave-assisted acid digestion method .The validity of methodology was checked by the certified human hair reference material (NCS ZC81002). The recovery of studied elements was found in the range of 98.1-99.2 % of certified reference material. The results of this study showed that the mean values of Al and Mn were significantly higher in scalp hair samples of all types of PSD as compared to referents subjects. The resulted data indicated a significant increase in the contents of Mn and Al in scalp hair samples of psychiatric patients than that of its control counterpart, which may provide prognostic tool for the diagnosis of the mental disorders. However, further work is suggested to examine the exact correlation between trace elements level and the degree of disorder. PMID:25947935

  12. Methylmercury exposure affects motor performance of a riverine population of the Tapajós river, Brazilian Amazon.

    PubMed

    Dolbec, J; Mergler, D; Sousa Passos, C J; Sousa de Morais, S; Lebel, J

    2000-04-01

    Gold mining and deforestation in the Brazilian Amazon are increasing mercury pollution of the extensive water system, exposing riverine populations to organic mercury through fish-eating. The aim of the present study was to evaluate the effect of such exposure on motor performance. This cross-sectional study was carried out in May 1996, in a village located on the banks of the Tapajós river in the Amazonian Basin, Brazil. Information concerning sociodemographics, health, smoking habits, alcohol drinking, dietary habits and work history were collected using an interview-administered questionnaire. Mercury concentrations were measured by cold vapor atomic absorption in blood and hair of each participant, of whom those aged between 15 and 79 years were assessed for motor performance (n = 84). Psychomotor performance was evaluated using the Santa Ana manual dexterity test, the Grooved Pegboard Fine motor test and the fingertapping motor speed test. Motor strength was measured by dynamometry for grip and pinch strength. Following the exclusion of 16 persons for previous head injury, working with mercury in the goldmining sites, or for diabetes, the relationship between performance and bioindicators of mercury was examined using multivariate statistical analyses, taking into account covariables. All participants in the study reported eating fish, which comprised 61.8% of the total meals eaten during the preceding week. The median hair total mercury concentration was 9 microg/g. Organic mercury accounted for 94.4 = 1.9% of the total mercury levels. Multivariate analysis of variance indicated that hair mercury was inversely associated with overall performance on the psychomotor tests, while a tendency was observed with blood mercury. Semipartial regression analyses showed that hair total mercury accounted for 8% to 16% of the variance of psychomotor performance. Neither hair nor blood total mercury was associated with the results of the strength tests in women and men

  13. Complications in hair restoration.

    PubMed

    Lam, Samuel M

    2013-11-01

    Hair restoration requires a high level of specialized skill on the part of both the surgeon and the assistant team. Recipient-site problems can manifest from either surgeon or assistant error. The surgeon can create an unnatural hairline due to lack of knowledge of natural hair-loss patterns or badly executed recipient sites. He must also be cognizant of how hairs naturally are angled on the scalp to re-create a pattern that appears natural when making recipient sites. Assistants can also greatly contribute to the success or failure of surgery in their task of graft dissection and graft placement. PMID:24200385

  14. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  15. [Hair colorants].

    PubMed

    Urbanek-Karłowska, B; Luks, E; Jedra, M; Kiss, E; Malanowska, M

    1997-01-01

    The properties, mode of action and its duration of the preparations used for hair dyeing are described, together with their chemical components, and also preparations of herbal origin. The chemical reactions are described in detail which lead the development of a color polymer occurring during hair dyeing. The studies are presented which are used for toxicological assessment of the raw materials which are the components of the colorants, and the list is included of hair colorants permitted for use in Poland. PMID:9562811

  16. Methylmercury degradation by Pseudomonas putida V1.

    PubMed

    Cabral, Lucélia; Yu, Ri-Qing; Crane, Sharron; Giovanella, Patricia; Barkay, Tamar; Camargo, Flávio A O

    2016-08-01

    Environmental contamination of mercury (Hg) has caused public health concerns with focuses on the neurotoxic substance methylmercury, due to its bioaccumulation and biomagnification in food chains. The goals of the present study were to examine: (i) the transformation of methylmercury, thimerosal, phenylmercuric acetate and mercuric chloride by cultures of Pseudomonas putida V1, (ii) the presence of the genes merA and merB in P. putida V1, and (iii) the degradation pathways of methylmercury by P. putida V1. Strain V1 cultures readily degraded methylmercury, thimerosal, phenylmercury acetate, and reduced mercuric chloride into gaseous Hg(0). However, the Hg transformation in LB broth by P. putida V1 was influenced by the type of Hg compounds. The merA gene was detected in P. putida V1, on the other hand, the merB gene was not detected. The sequencing of this gene, showed high similarity (100%) to the mercuric reductase gene of other Pseudomonas spp. Furthermore, tests using radioactive (14)C-methylmercury indicated an uncommon release of (14)CO2 concomitant with the production of Hg(0). The results of the present work suggest that P. putida V1 has the potential to remove methylmercury from contaminated sites. More studies are warranted to determine the mechanism of removal of methylmercury by P. putida V1. PMID:27062344

  17. Evaluated the levels of lead and cadmium in scalp hair of adolescent boys consuming different smokeless tobacco products with related to controls.

    PubMed

    Arain, Sadaf S; Kazi, Tasneem G; Arain, Asma J; Afridi, Hassan I; Brahman, Kapil D; Naeemullah; Ali, Jamshed; Memon, G Zuhra

    2015-04-01

    The present study was aimed to evaluate the cadmium (Cd) and lead (Pb) levels in the scalp hair samples of adolescent boys age ranged 12-15 years, chewing different smokeless tobacco (SLT) products. For comparative purpose, boys of the same age group who did not consume any SLT products were selected as referents. The concentrations of Cd and Pb in SLT products and the scalp hair samples were measured by electrothermal atomic absorption spectrophotometer (ETAAS) after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by certified reference materials (CRMs). The difference between experimental and certified values of both elements was not significant (p > 0.05). The resulted data indicated that the adolescent boys who consumed different SLT products have two- to threefold higher levels of Cd and Pb in the scalp hair samples as compared to the referent boys (p < 0.01). The adolescent chewing different SLT products have 82.2-110 and 60.6-94.5% higher levels of Cd and Pb, respectively, in their scalp hair as related to the referents. PMID:25537077

  18. Protective effect of selenium on methylmercury toxicity: a possible mechanism

    SciTech Connect

    Chang, L.W.; Suber, R.

    1982-09-01

    Young adult male Charles River rats were injected (i.p.) with 2.0 mg/kg b.w. methylmercury chloride (MeHg), with 2.0 mg/kg b.w. sodium selenite (Se), or with 2.0 mg/kg b.w. MeHg and 2.0 mg/kg b.w. Se. Erythrocytic glutathione peroxidase activity was determined and the rate of oxidation of NADPH with t-butyl-hydroperoxide as a substrate was followed at 340 nm and 25/sup 0/C. Toxic signs (crossing reflex of the hind limbs) were displayed by MeHg-treated animals by the 6th week of intoxication. By 8 weeks of the experiment, overt neurological signs (crossing reflex, ataxic gait, and weight loss) were observed in MeHg-treated animals. No observable toxic signs or symptoms were evident in the control animals (saline or Se-treated) and in the MeHg/Se treated rats. Results have confirmed that exposure to methyl-mercury suppresses the activity of glutathione peroxidase. Furthermore, it was demonstrated that with co-administration of selenium (sodium selenite), the inhibitory effect of MeHg on GSH-Px was totally alleviated. These findings suggest that the level of GSH-Px level is important in influencing the toxic consequences in MeHg-intoxicated animals and may be useful as a predictive indicator for methylmercury toxic conditions of the animals. (JMT)

  19. Prenatal Organochlorine and Methylmercury Exposure and Memory and Learning in School-Age Children in Communities Near the New Bedford Harbor Superfund Site, Massachusetts

    PubMed Central

    Orenstein, Sara T.C.; Thurston, Sally W.; Bellinger, David C.; Schwartz, Joel D.; Amarasiriwardena, Chitra J.; Altshul, Larisa M.

    2014-01-01

    Background: Polychlorinated biphenyls (PCBs), organochlorine pesticides, and methylmercury (MeHg) are environmentally persistent with adverse effects on neurodevelopment. However, especially among populations with commonly experienced low levels of exposure, research on neurodevelopmental effects of these toxicants has produced conflicting results. Objectives: We assessed the association of low-level prenatal exposure to these contaminants with memory and learning. Methods: We studied 393 children, born between 1993 and 1998 to mothers residing near a PCB-contaminated harbor in New Bedford, Massachusetts. Cord serum PCB, DDE (dichlorodiphenyldichloroethylene), and maternal peripartum hair mercury (Hg) levels were measured to estimate prenatal exposure. Memory and learning were assessed at 8 years of age (range, 7–11 years) using the Wide Range Assessment of Memory and Learning (WRAML), age-standardized to a mean ± SD of 100 ± 15. Associations with each WRAML index—Visual Memory, Verbal Memory, and Learning—were examined with multivariable linear regression, controlling for potential confounders. Results: Although cord serum PCB levels were low (sum of four PCBs: mean, 0.3 ng/g serum; range, 0.01–4.4), hair Hg levels were typical of the U.S. fish-eating population (mean, 0.6 μg/g; range, 0.3–5.1). In multivariable models, each microgram per gram increase in hair Hg was associated with, on average, decrements of –2.8 on Visual Memory (95% CI: –5.0, –0.6, p = 0.01), –2.2 on Learning (95% CI: –4.6, 0.2, p = 0.08), and –1.7 on Verbal Memory (95% CI: –3.9, 0.6, p = 0.14). There were no significant adverse associations of PCBs or DDE with WRAML indices. Conclusions: These results support an adverse relationship between low-level prenatal MeHg exposure and childhood memory and learning, particularly visual memory. Citation: Orenstein ST, Thurston SW, Bellinger DC, Schwartz JD, Amarasiriwardena CJ, Altshul LM, Korrick SA. 2014. Prenatal

  20. Total Mercury and Methylmercury Dynamics; stream export in an upland forested watershed in the Adirondack region of New York State

    NASA Astrophysics Data System (ADS)

    Carleton, W.; Vidon, P.; Mitchell, M. J.

    2012-12-01

    Although levels of mercury and acid rain deposition have greatly declined in recent years due to legislation controls on industry emissions, their legacy has had a lasting effect on the Adirondack region of New York State. This historical mercury deposition is of concern because of the high chance for methylmercury production and export to occur. The impact of forested uplands on methylmercury export remains poorly understood in relation to other ecosystems. Research indicates that sulfate dynamics play a large role in regulating the production of methylmercury in the presence of inorganic mercury; however the relationship between methylmercury production and nitrate availability at various times of the year is less understood, yet, hypothesized to potentially impact sulfate reduction and ultimately methylmercury production in a variety of ecosystems. In this study, mercury and water quality (including sulfate and nitrate) will be monitored in spring, summer and fall of 2012 at 7 locations in Arbutus Watershed, Adirondacks, NY. Proxies (UV absorbance, Fluorescence indices) for total mercury and methylmercury will be utilized to predict export. The main objectives of this research are to determine the relevance of forested uplands in methylmercury export, as well as gain further understanding of mercury dynamics and associated proxies in relation to nitrate and sulfate availability. Photo courtesy of the Adirondack Ecological Center

  1. Nutritional factors and hair loss.

    PubMed

    Rushton, D H

    2002-07-01

    The literature reveals what little is known about nutritional factors and hair loss. What we do know emanates from studies in protein-energy malnutrition, starvation, and eating disorders. In otherwise healthy individuals, nutritional factors appear to play a role in subjects with persistent increased hair shedding. Hård, 40 years ago, demonstrated the importance of iron supplements in nonanaemic, iron-deficient women with hair loss. Serum ferritin concentrations provide a good assessment of an individual's iron status. Rushton et al. first published data showing that serum ferritin concentrations were a factor in female hair loss and, 10 years later, Kantor et al. confirmed this association. What level of serum ferritin to employ in subjects with increased hair shedding is yet to be definitively established but 70 micro g/L, with a normal erythrocyte sedimentation rate (< 10 mm/h), is recommended. The role of the essential amino acid, l-lysine in hair loss also appears to be important. Double-blind data confirmed the findings of an open study in women with increased hair shedding, where a significant proportion responded to l-lysine and iron therapy. There is no evidence to support the popular view that low serum zinc concentrations cause hair loss. Excessive intakes of nutritional supplements may actually cause hair loss and are not recommended in the absence of a proven deficiency. While nutritional factors affect the hair directly, one should not forget that they also affect the skin. In the management of subjects with hair loss, eliminating scaling problems is important as is good hair care advice and the need to explain fully the hair cycle. Many individuals reduced their shampooing frequency due to fear of losing more hair but this increases the amount seen in subsequent shampoos fuelling their fear of going bald and adversely affecting their quality of life. PMID:12190640

  2. Hair and fiber transfer in an abduction case--evidence from different levels of trace evidence transfer.

    PubMed

    Taupin, J M

    1996-07-01

    Levels of trace evidence transfer were examined in a casework context. A girl was allegedly abducted in a car and rape attempted by the accused, who denied any contact with the victim. Clothing worn by the victim and the accused, and the covers from the front seats of the car, were analyzed for trace evidence. Three types of corresponding fibers and four possible pathways of transfer were identified. Synthetic fibers similar to those composing the car seat covers were located on the victim's clothing, consistent with direct transfer. Secondary transfer was indicated by dyed brown human head-type hairs (possibly originating from the accused's wife) located on the seat covers and on the victim's clothing. Secondary and possibly tertiary transfer was indicated by pink synthetic material and associated fibers (possibly originating from the victim's mother) located on the victim's clothing, a car seat cover and the accused's clothing. Light microscopy, comparison microscopy, and cross-sectioning techniques were used. The multiple fiber matches and the differing pathways and levels of transfer increased the strength of the association between the accused and the victim. After the fiber evidence was led at the trial, the accused pleaded guilty, thereby affirming the value of secondary transfer evidence. PMID:8754584

  3. Ingrowing Hair

    PubMed Central

    Luo, Di-Qing; Liang, Yu-Hua; Li, Xi-Qing; Zhao, Yu-Kun; Wang, Fang; Sarkar, Rashmi

    2016-01-01

    Abstract Cutaneous pili migrans and creeping eruption caused by parasitic diseases may present as a moving linear lesion in skin. The former, caused by a hair shaft or fragment embedded in the superficial skin or middle dermis, is a rare condition characterized by creeping eruption with a black line observed at the advancing end. In exceptionally rare instance, the hair grows inside the skin and burrows in the uppermost dermis, such a condition has been called “ingrown hair.” We report a 30-year-old Chinese man, who was accustomed to pull or extrude the beard hairs, with 1-year history of slowly extending black linear eruption on his right chin. Cutaneous examination revealed a 4-cm long black linear lesion beneath the skin associated with edematous erythema around and folliculitis on both ends of the lesion. After treatment with topical mupirocin ointment, the erythema and folliculitis improved and 2 hairs of the beard with hair follicles were pulled out from the skin. Two weeks later, another similar black line about 1 cm in length in the skin presented on the prior lesional area, which was pulled out by a shallow incision of the skin and was also demonstrated as a beard hair with hair follicle. The patient was diagnosed as “ingrowing hair” with multiple recurrences. The lesions recovered after the beard hairs were pulled out. No recurrence occurred in a year of follow-up. We suggest that “ingrowing hair” is better than “ingrown hair” to describe such a condition. Pulling out the involved hair and correcting the bad practice are its optimal management strategies. PMID:27175694

  4. Quantifying Isoniazid Levels in Small Hair Samples: A Novel Method for Assessing Adherence during the Treatment of Latent and Active Tuberculosis

    PubMed Central

    Gerona, Roy; Wen, Anita; Chin, Aaron T.; Koss, Catherine A.; Bacchetti, Peter; Metcalfe, John; Gandhi, Monica

    2016-01-01

    Background Tuberculosis (TB) is the leading cause of death from an infectious pathogen worldwide and the most prevalent opportunistic infection in people living with HIV. Isoniazid preventive therapy (IPT) reduces the incidence of active TB and reduces morbidity and mortality in HIV-infected patients independently of antiretroviral therapy. However, treatment of latent or active TB is lengthy and inter-patient variability in pharmacokinetics and adherence common. Current methods of assessing adherence to TB treatment using drug levels in plasma or urine assess short-term exposure and pose logistical challenges. Drug concentrations in hair assess long-term exposure and have demonstrated pharmacodynamic relevance in HIV. Methods A large hair sample from a patient with active TB was obtained for assay development. Methods to pulverize hair and extract isoniazid were optimized and then the drug detected by liquid chromatography/ tandem mass spectrometry (LC/MS-MS). The method was validated for specificity, accuracy, precision, recovery, linearity and stability to establish the assay’s suitability for therapeutic drug monitoring (TDM). Hair samples from patients on directly-observe isoniazid-based latent or active TB therapy from the San Francisco Department of Public Health TB clinic were then tested. Results Our LC/MS-MS-based assay detected isoniazid in quantities as low as 0.02ng/mg using 10–25 strands hair. Concentrations in spiked samples demonstrated linearity from 0.05–50ng/mg. Assay precision and accuracy for spiked quality-control samples were high, with an overall recovery rate of 79.5%. In 18 patients with latent or active TB on treatment, isoniazid was detected across a wide linear dynamic range. Conclusions An LC-MS/MS-based assay to quantify isoniazid levels in hair with performance characteristics suitable for TDM was developed and validated. Hair concentrations of isoniazid assess long-term exposure and may be useful for monitoring adherence to

  5. Heat stress, divergent nutrition level, and late pregnancy in hair sheep: effects upon cotyledon development and litter weight at birth.

    PubMed

    Meza-Herrera, César Alberto; Vicente-Pérez, Arnulfo; Osorio-Marín, Yolanda; Girón-Gómez, Blenda Sinahí; Beltran-Calderon, Eira; Avendaño-Reyes, Leonel; Correa-Calderon, Abelardo; Macías-Cruz, Ulises

    2015-06-01

    The effect of two divergent nutritional levels during late pregnancy upon some physiological variables and the number (NC) and diameter (DC) of placental cotyledons along with litter weight at birth (LWB) on heat-stressed (42-45 °C) hair ewes was evaluated. Multiparous Katahdin x Pelibuey ewes (n = 24) at the onset of the 3/3 of pregnancy were randomly assigned to two treatments (n = 12): (1) non-nutritionally restricted (NNR) ewes, with free access to wheat straw plus 500 g/day of concentrate, and (2) nutritionally restricted (NR) ewes, receiving only wheat straw ad libitum. On days 100, 115, 130, and 145 of gestation, the body weight (BW), body condition score (BCS), rectal temperature (RT), respiration rate (RR) were registered in the afternoon (15:00) while the temperature-humidity index (THI) was calculated. At lambing, NC, DC, and LWB were also registered. Analyses considered a completely random design (CRD)-ANOVA with repeated measures across time, considering to litter size (LS) as covariable to reduce any possible influence of LS upon the response variables along experimental diets. BW and BCS were higher in NNR ewes at days 115, 130, and 145. Despite RT similarities (P < 0.05) between treatments, RR was greater (P < 0.01) in the NNR ewes, particularly towards the end of the experimental period. The observed THI averages confirmed severe heat stress conditions on ewes all day round across the experimental period, yet, NC, DC, and LWB favored (P < 0.05) to the NNR ewes. Despite that NNR ewes faced a significant heat stress based on the observed THI values, they consumed a diet with an increased energy-protein density, suggesting that the increased RR in the NNR group was exerted as a compensatory thermoregulation mechanism. Nutritional supplementation in hair ewes besides to an increase the energy body reserves (BW and BCS) also improved both the number and size of cotyledons, while generated an increased litter weight at birth. PMID

  6. [Fish and seafood as a source of human exposure to methylmercury].

    PubMed

    Mania, Monika; Wojciechowska-Mazurek, Maria; Starska, Krystyna; Rebeniak, Małgorzata; Postupolski, Jacek

    2012-01-01

    Fish and seafood are recommended diet constituents providing high quality protein, vitamins, minerals and omega-3 fatty acids, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, these foodstuffs can also be the major source ofmethylmercury intake in humans. In general, more than 90% of the mercury in fish is found as methylmercury, but contents of methylmercury can vary considerably between species. Predatory species that are at the top of the food chain and live a long time, may accumulate higher levels of methylmercury. This paper contains information about sources of human exposure to organic compounds of mercury, toxicity, metabolism and transformation of mercury in the environment. Assessment of methylmercury by international risk assessment bodies such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and U.S. National Research Council (NRC) were presented. Climate changes and their influence on the mercury cycle in the environment especially mercury methylation and concentrations of methylmercury in marine species were also presented. Consumer advice prepared by European Commission and Member States as regards consumption of predatory fishes such as swordfish, tuna, shark, marlin and pike, taking into account the most vulnerable groups of population e.g. women planning pregnancy, pregnant or breastfeeding women and children were presented. Mercury and methylmercury contamination of fishes and seafood on the basis of the literature references as well as intake of mercury with fish and fish products in Poland and other European country were discussed. The role of selenium as a factor which counteracts methylmercury toxicity and protects against some neurological effects of methylmercury exposure in humans, as well as information on potential etiological factors connected with autism disorder were also described. Attention has also been drawn to increasing number of notifications to Rapid Alert System for Food and Feed

  7. Hair Loss

    MedlinePlus

    ... En Español Making a Change – Your Personal Plan Hot Topics Meningitis Choosing Your Mood Prescription Drug Abuse ... much heat on your hair (like using a hot iron or hot blow drying). Another type of ...

  8. Dry hair

    MedlinePlus

    ... or using harsh soaps or alcohols Excessive blow-drying Dry air Menkes kinky hair syndrome Malnutrition Underactive ... or twice a week Add conditioners Avoid blow drying and harsh styling products

  9. Hair Loss

    MedlinePlus

    ... problems, diabetes, or lupus. If you take certain medicines or have chemotherapy for cancer, you may also ... cause will correct the problem. Other treatments include medicines and hair restoration.

  10. EFFECTS OF DIETARY METHYLMERCURY EXPOSURE ON AMERICAN KESTRELS

    EPA Science Inventory

    Several recent ecological risk assessments and criteria development efforts suggest that sensitive individuals of some piscivorous (fish eating) wildlife populations may be experiencing adverse effects from methylmercury exposure. The primary exposure route of methylmercury to t...

  11. Biomarkers of Methylmercury Exposure Immunotoxicity among Fish Consumers in Amazonian Brazil

    PubMed Central

    Fillion, Myriam; Barbosa, Fernando; Shirley, Devon L.; Chine, Chiameka; Lemire, Melanie; Mergler, Donna; Silbergeld, Ellen K.

    2011-01-01

    Background: Mercury (Hg) is a ubiquitous environmental contaminant with neurodevelopmental and immune system effects. An informative biomarker of Hg-induced immunotoxicity could aid studies on the potential contribution to immune-related health effects. Objectives: Our objectives were to test the hypothesis that methylmercury (MeHg) exposures affect levels of serum biomarkers and to examine interactions between Hg and selenium (Se) in terms of these responses. Methods: This cross-sectional epidemiological study assessed adults living along the Tapajós River, a system long affected by MeHg. We measured antinuclear (ANA) and antinucleolar (ANoA) autoantibody levels and eight cytokines in serum samples (n = 232). Total Hg (including MeHg) and Se were measured in blood, plasma, hair, and urine. Results: The median (range) total Hg concentrations were 14.1 μg/g (1.1–62.4), 53.5 μg/L (4.3–288.9), 8.8 μg/L (0.2–40), and 3.0 μg/L (0.2–16.1) for hair, blood, plasma, and urine, respectively. Elevated titers of ANA (but not ANoA) were positively associated with MeHg exposure (log-transformed, for blood and plasma), unadjusted [odds ratio (OR) = 2.6; 95% confidence interval (CI): 1.1, 6.2] and adjusted for sex and age (OR = 2.9; 95% CI: 1.1, 7.5). Proinflammatory [interleukin (IL)-6 and interferon (IFN)-©], anti-inflammatory (IL-4), and IL-17 cytokine levels were increased with MeHg exposure; however, in the subset of the population with elevated ANA, proinflammatory IL-1®, IL-6, IFN-©, and tumor necrosis factor (TNF)-〈 and anti-inflammatory (IL-4) cytokine levels were decreased with MeHg exposure. Although Se status was associated with MeHg level (correlation coefficient = 0.86; 95% CI: 0.29, 1.43), Se status was not associated with any changes in ANA and did not modify associations between Hg and ANA titers. Conclusions: MeHg exposure was associated with an increased ANA and changes in serum cytokine profile. Moreover, alterations in serum cytokine profiles

  12. Does methylmercury have a role in causing developmental disabilities in children?

    PubMed Central

    Myers, G J; Davidson, P W

    2000-01-01

    Methylmercury (MeHg) is a potent neurotoxin that in high exposures can cause mental retardation, cerebral palsy, and seizures. The developing brain appears particularly sensitive to MeHg. Exposure levels in pregnant experimental animals that do not result in detectable signs or symptoms in the mother can adversely affect the offspring's development. Studies of human poisonings suggest this may also occur in humans. Human exposure to MeHg is primarily dietary through the consumption of fish: MeHg is present in all fresh and saltwater fish. Populations that depend on fish as a major source of dietary protein may achieve MeHg exposure levels hypothesized to adversely affect brain development. Increasing mercury levels in the environment have heightened concerns about dietary exposure and a possible role for MeHg in developmental disabilities. Follow-up studies of an outbreak of MeHg poisoning in Iraq revealed a dose-response relationship for prenatal MeHg exposure. That relationship suggested that prenatal exposure as low as 10 ppm (measured in maternal hair growing during pregnancy) could adversely affect fetal brain development. However, using the same end points as were used in the Iraq study, no associations have been reported in fish-eating populations. Using a more extensive range of developmental end points, some studies of populations consuming seafood have reported associations with prenatal MeHg exposure, whereas others have found none. This paper reviews the data presently available associating MeHg exposure with development and poses some of the unanswered questions in this field. Images Figure 1 Figure 2 PMID:10852838

  13. Evaluation of glutathione S-transferase GSTM1 and GSTT1 polymorphisms and methylmercury metabolism in an exposed Amazon population.

    PubMed

    Mazzaron Barcelos, Gustavo Rafael; de Marco, Kátia Cristina; Grotto, Denise; Valentini, Juliana; Garcia, Solange Cristina; Leite Braga, Gilberto Úbila; Barbosa, Fernando

    2012-01-01

    Over the last decades, the presence of methylmercury (MeHg) in the Amazon region of Brazil and its adverse human health effects have given rise to much concern. The biotransformation of MeHg occurs mainly through glutathione (GSH) in the bile mediated by conjugation with glutathione S-transferases (GST). Epidemiological evidence has shown that genetic polymorphisms may affect the metabolism of MeHg. The aim of this study was to evaluate the association between GST polymorphisms, GSH, and Hg levels in blood (B-Hg) and in hair (H-Hg) of an Amazon population chronically exposed to the metal through fish consumption. Blood and hair samples were collected from 144 volunteers (71 men, 73 women). B-Hg and H-Hg levels were determined by inductively coupled plasma-mass spectrometry, and GSH levels were evaluated by a spectrophotometric method. GSTM1 and T1 genotyping evaluation were carried out by multiplex polymerase chain reaction (PCR). Mean levels of B-Hg and H-Hg were 37.7 ± 24.5 μg/L and 10.4 ± 7.4 μg/g, respectively; GSH concentrations ranged from 0.52 to 2.89 μM/ml of total blood. Distributions for GSTM1/T1, GSTM1/GSTT1*0, GSTM1*0/T1, and GSTM1*0/GSTT1*0 genotypes were 35.4, 22.2, 25.0, and 17.4%, respectively. GSTT1 genotype carriers presented lower levels of B-Hg and H-Hg when compared to other genotypes carriers. In addition, GSTM1*0/GSTT1*0 individuals presented higher Hg levels in blood and hair than subjects presenting any other genotypes. There appeared to be no evidence of an effect of polymorphisms on GSH levels. Therefore, our data suggest that GST polymorphisms may be associated with MeHg detoxification. PMID:22852846

  14. Comparison of lead and zinc levels in the hair of pupils from four towns in the Kumasi Municipal Area of Ghana

    SciTech Connect

    Golow, A.A.; Kwaansa-Ansah, E.E. )

    1994-09-01

    When metals enter the body of living organisms, even in trace amounts, they may not be metabolized and may accumulate if not excreted. During the process of accumulation they may attain levels which may be toxic to the organism. In the body some of the metals may accumulate in special organs or tissues where they may effect changes. Others may remain in the general body fluid and influence all enzyme systems. Some of these influences may be beneficial and others detrimental. Hence it is important to learn of metals which enter the body so that any undue increases in their amounts may be avoided. The bone is usually the site for the accumulation of metals and may serve as a store house and contain a library of the record of what have entered the body of the organism. However human bone is not easy to sample. The hair, though lesser known as site for accumulation of metals, it accumulates more lead per unit weight than any tissue in the body including even body fluids such as blood and urine. The human hair, depending upon the belief, culture and scientific awareness of the people may be easy or difficult to sample. In many instances the hair of humans especially that of males is cut and disposed off as waste materials. Apparently such unwanted hair could be analyzed and studied to learn of both external and internal exposure of the population to contamination and pollution. A knowledge of levels of metals in non-occupationally exposed citizens as compared with those in occupationally exposed people may serve as a guide in protecting the whole population against industrial pollution and its associated diseases. The report presented here is part of a project designed to find the levels of metals in the hair of the population in general before looking at the levels which may be obtained in some mine workers or occupationally exposed, in the country. Such levels may serve as natural background levels for future reference. 10 refs., 3 figs., 2 tabs.

  15. Role of hydrosulfide ions (HS-) in methylmercury resistance in Saccharomyces cerevisiae.

    PubMed Central

    Ono, B; Ishii, N; Fujino, S; Aoyama, I

    1991-01-01

    Methylmercury-resistant mutants were obtained from Saccharomyces cerevisiae. They were divided into two complementation groups, met2 (homoserine O-acetyltransferase deficiency) and met15 (enzyme deficiency unknown), as reported previously. It was found that met15 was allelic to met17 (O-acetylserine and O-acetylhomoserine sulfhydrylase deficiency). Methylmercury toxicity was counteracted by exogenously added HS-, and both met2 and met17 (met15) mutants overproduced H2S. On the basis of these results, we conclude that met2 and met17 (met15) cause accumulation of hydrosulfide ions in the cell and that the increased level of hydrosulfide is responsible for detoxification of methylmercury. Images PMID:1781681

  16. Removing Hair Safely

    MedlinePlus

    ... the skin, and into the hair follicle. An electric current travels down the wire and destroys the hair ... a period of time. Tweezer epilators also use electric current to remove hair. The tweezers grasp the hair ...

  17. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals

    SciTech Connect

    Goodrich, Jaclyn M.; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2011-12-15

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione s-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n = 515), and total mercury content was measured. Average urine (1.06 {+-} 1.24 ug/L) and hair mercury levels (0.49 {+-} 0.63 ug/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5 Prime ), or both (SEPP1 3 Prime UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). -- Highlights: Black-Right-Pointing-Pointer We explore the influence of 15 polymorphisms on urine and hair Hg levels. Black-Right-Pointing-Pointer Urine and hair Hg levels in dental professionals were similar to the US population. Black-Right-Pointing-Pointer GSTT1 and SEPP1 polymorphisms associated with urine Hg levels. Black

  18. A review of methylmercury and child development.

    PubMed

    Myers, G J; Davidson, P W; Shamlaye, C F

    1998-04-01

    Methylmercury (MeHg) is a neurotoxin present in both fresh and saltwater fish throughout the world. Increased levels of MeHg can be found in individuals who regularly consume fish. The developing brain is very sensitive to the deleterious effects of MeHg, and prenatal exposure can occur when the mother has a diet high in fish. If the level of MeHg exposure achieved by eating fish adversely affects the fetus or child's neurological development it could have far reaching public health implications. Studies of human prenatal MeHg poisoning in Iraq suggest that MeHg levels achieved by eating fish may affect neurological development even when the fish MeHg levels are not elevated by obvious pollution. Studies in fish eating populations have identified adverse neurological and developmental outcomes, but these findings have not been consistent. Additional studies are presently underway to determine whether consistent adverse outcomes can be identified using more sensitive testing methods and examining children older than in previous studies. This review examines studies of human prenatal and postnatal MeHg exposure. Studies of poisoning episodes where children are symptomatic and studies of fish eating populations where no symptoms are apparent will be addressed. Individuals around the world depend on fish as a protein source and increasing evidence suggests that regular fish consumption has cardiovascular benefits. It is not presently clear whether MeHg exposures from a high fish diet adversely affect children's neurological development, but it is an important question to answer. PMID:9553968

  19. Glutathione enzyme and selenoprotein polymorphisms associate with mercury biomarker levels in Michigan dental professionals.

    PubMed

    Goodrich, Jaclyn M; Wang, Yi; Gillespie, Brenda; Werner, Robert; Franzblau, Alfred; Basu, Niladri

    2011-12-01

    Mercury is a potent toxicant of concern to both the general public and occupationally exposed workers (e.g., dentists). Recent studies suggest that several genes mediating the toxicokinetics of mercury are polymorphic in humans and may influence inter-individual variability in mercury accumulation. This work hypothesizes that polymorphisms in key glutathione synthesizing enzyme, glutathione S-transferase, and selenoprotein genes underlie inter-individual differences in mercury body burden as assessed by analytical mercury measurement in urine and hair, biomarkers of elemental mercury and methylmercury, respectively. Urine and hair samples were collected from a population of dental professionals (n=515), and total mercury content was measured. Average urine (1.06±1.24 microg/L) and hair mercury levels (0.49±0.63 microg/g) were similar to national U.S. population averages. Taqman assays were used to genotype DNA from buccal swab samples at 15 polymorphic sites in genes implicated in mercury metabolism. Linear regression modeling assessed the ability of polymorphisms to modify the relationship between mercury biomarker levels and exposure sources (e.g., amalgams, fish consumption). Five polymorphisms were significantly associated with urine mercury levels (GSTT1 deletion), hair mercury levels (GSTP1-105, GSTP1-114, GSS 5'), or both (SEPP1 3'UTR). Overall, this study suggests that polymorphisms in selenoproteins and glutathione-related genes may influence elimination of mercury in the urine and hair or mercury retention following exposures to elemental mercury (via dental amalgams) and methylmercury (via fish consumption). PMID:21967774

  20. Reanalysis of dose-response data from the Iraqi methylmercury poisoning episode

    SciTech Connect

    Crump, K.; Clewell, H.; Gearhart, J.

    1995-08-01

    Applying a hockey stick parametric dose-response model to data on late or retarded development in Iraqi children exposed in utero to methylmercury, with mercury (Hg) exposure characterized by the peak Hg concentration in mothers` hair during pregnancy, Cox et al. calculated the {open_quotes}best statistical estimate{close_quotes} of the threshold for health effects as 10 ppm Hg in hair with a 95% range of uncertainty of between 0 and 13.6 ppm. A new application of the hockey stick model to the Iraqi data shows, however, that the statistical upper limit of the threshold based on the hockey stick model could be as high as 255 ppm. Futhermore, the maximum likelihood estimate of the threshold using a different parametric model is virtually zero. These and other analyses demonstrate that threshold estimates based on parametric models exhibit high statistical variability and model dependency, and are highly sensitive to the precise definition of an abnormal response. Consequently, they are not a reliable basis for setting a reference dose (RfD) for methylmercury. Benchmark analyses and statistical analyses useful for deriving NOAELs are also presented. We believe these latter analyses-particularly the benchmark analyses-generally form a sounder basis for determining RfDs than the type of hockey stick analysis presented by Cox et al. However, the acute nature of the exposures, as well as other limitations in the Iraqi data suggest that other data may be more appropriate for determining acceptable human exposures to methylmercury. 24 refs., 5 figs., 2 tabs.

  1. Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review

    PubMed Central

    Burke, Thomas A; Navas-Acien, Ana; Breysse, Patrick N; McGready, John; Fox, Mary A

    2014-01-01

    Abstract Objective To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity. Methods A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Findings Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value. Conclusion There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries. PMID:24700993

  2. ACCUMULATION OF METHYLMERCURY OR POLYCHLORINATED BIPHENYLS IN IN VITRO MODELS OF RAT NEURONAL TISSUE.

    EPA Science Inventory

    This manuscript reports data examining the accumulation of PCBs or methylmercury into the tissue of three commonly used in vitro neuronal models.

    ? The results demonstrate that these lipophilic compounds can accumulate to levels 5 to 100 fold higher than the surrounding s...

  3. Patterns and Consequences of in ovo Exposure to Methylmercury in Common Loons, poster presentation

    EPA Science Inventory

    A critical component of a common loon/mercury (Hg) risk assessment model under development is the determination of the concentration of Hg in eggs that poses a population level risk. We conducted a field study to (1) characterize in ovo methylmercury (MeHg) exposure in Wisconsin...

  4. Effects of Injected Methylmercury on the Hatching of Common Loon (Gavia immer) Eggs

    EPA Science Inventory

    To determine the level of in ovo methylmercury (MeHg) exposure that results in detrimental effects on fitness and survival of loon embryos and hatched chicks, we conducted a field study in which we injected eggs with various doses of MeHg on day 4 of incubation. Eggs were collect...

  5. Mercury stable isotope fractionation in a tropical ecosystem including human hair: New insights for an isotope balance

    NASA Astrophysics Data System (ADS)

    Laffont, Laure; Sonke, Jeroen; Maurice, Laurence; Behra, Philippe

    2010-05-01

    . Both anomalies ∆201Hg vs. ∆199Hg are linearly correlated with a slope of +1.12‰ for native hair and a mass dependant fractionation (MDF) of ~+2‰ has been evidenced between native communities hair and fish species constituting their diet. For the same fish species, MIF anomalies differ with floodplain lakes and drainage basins suggesting that the methylmercury (MMHg) analysed in fish caught in floodplain lake reflects the photodemethylation process while in the Beni R. mainstream the negative anomalies confirm that this photochemical reactions are limited. Within the aquatic food chain of an hydrosystem, it appears that MIF anomalies can trace the fish ecology and the aquatic photochemical processes, while mass dependent fractionation can trace the trophic level as a result of excretion and metabolic processes involving mercury in the body.

  6. Hair Loss

    MedlinePlus

    ... psychosocial impact of hair loss have found patients’ self-esteem, body image and self-confidence to be negatively ... 1-2 Known psychosocial complications include depression, low self-esteem, altered self-image, and less frequent and enjoyable ...

  7. Oxidative stress in songbirds exposed to dietary methylmercury.

    PubMed

    Henry, Katie A; Cristol, Daniel A; Varian-Ramos, Claire W; Bradley, Eric L

    2015-04-01

    Long-term, sublethal methylmercury exposure can cause reproductive depression, immune suppression, endocrine disruption and other problems in birds. We used two biomarkers to detect oxidative stress in livers of zebra finches (Taeniopygia guttata) developmentally exposed to sublethal levels of dietary methylmercury (0.0, 0.3, 0.6, 1.2, or 2.4 μg/g wet weight in diet). Our findings indicate that young adult finches exposed to environmentally relevant concentrations of mercury in ovo and through their diets, exhibited oxidative stress in their livers. We measured the ratio of the antioxidant glutathione in its reduced form (GSH) versus its oxidized form (GSSG) and the activity of the superoxide dismutase (SOD) enzyme suite. Blood total mercury served as a proxy for liver mercury concentration, and was on average 8.4 times the dietary dose (e.g., birds consuming 0.6 μg/g had blood mercury levels of ~5 μg/g on a wet weight basis). Consistent with what is known from large, aquatic bird species, there was a significant, negative relationship between GSH/GSSG ratios and tissue mercury concentrations, which is indicative of oxidative stress. This relationship was driven by a significant increase in the oxidized glutathione in the livers of birds with higher blood mercury levels. SOD activity was also found to have a significant, negative relationship with blood mercury. PMID:25519780

  8. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes): Monitoring Hair Cortisol and Behaviors.

    PubMed

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Inoue-Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC). Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1) and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS), Kyoto University (Study 2). We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals' experiences of aggression and sex may be more important contributors to long-term stress than relocation alone. PMID

  9. Effects of Relocation and Individual and Environmental Factors on the Long-Term Stress Levels in Captive Chimpanzees (Pan troglodytes): Monitoring Hair Cortisol and Behaviors

    PubMed Central

    Yamanashi, Yumi; Teramoto, Migaku; Morimura, Naruki; Hirata, Satoshi; Inoue-Murayama, Miho; Idani, Gen'ichi

    2016-01-01

    Understanding the factors associated with the long-term stress levels of captive animals is important from the view of animal welfare. In this study, we investigated the effects of relocation in addition to individual and environmental factors related to social management on long-term stress level in group-living captive chimpanzees by examining behaviors and hair cortisol (HC). Specifically, we conducted two studies. The first compared changes in HC levels before and after the relocation of 8 chimpanzees (Study 1) and the second examined the relationship between individual and environmental factors and individual HC levels in 58 chimpanzees living in Kumamoto Sanctuary (KS), Kyoto University (Study 2). We hypothesized that relocation, social situation, sex, and early rearing conditions, would affect the HC levels of captive chimpanzees. We cut arm hair from chimpanzees and extracted and assayed cortisol with an enzyme immunoassay. Aggressive behaviors were recorded ad libitum by keepers using a daily behavior monitoring sheet developed for this study. The results of Study 1 indicate that HC levels increased during the first year after relocation to the new environment and then decreased during the second year. We observed individual differences in reactions to relocation and hypothesized that social factors may mediate these changes. In Study 2, we found that the standardized rate of receiving aggression, rearing history, sex, and group formation had a significant influence on mean HC levels. Relocation status was not a significant factor, but mean HC level was positively correlated with the rate of receiving aggression. Mean HC levels were higher in males than in females, and the association between aggressive interactions and HC levels differed by sex. These results suggest that, although relocation can affect long-term stress level, individuals’ experiences of aggression and sex may be more important contributors to long-term stress than relocation alone

  10. Levels of mercury in scalp hair of fishermen and their families from Camara de Lobos-Madeira (Portugal): A preliminary study

    SciTech Connect

    Gaggi, C.; Zino, F.; Duccini, M.; Renzoni, A.

    1996-12-31

    Mercury is probably one of the most investigated natural and anthropogenic contaminants, especially in aquatic environments. Among the inorganic forms, elemental mercury (HgO) presents a marked tendency to reach the air as vapor, and in terrestrial systems to bioaccumulate in plant biomass, whereas other inorganic compounds (e.g., mercury sulphide) are characterized by low mobility and bioavailability. These last compounds once in water (and especially at the water-sediment interface) can undergo a process of methylation. Methylmercury (MeHg) is readily bioaccumulated by aquatic organisms and leads to a phenomenon of enrichment from lower to higher trophic level. The extensive literature on MeHg and human health shows that the consumption of fish and/or shellfish is the main source of exposure, the contribution from air and water being negligible and mainly related to inorganic forms. A human population consuming large amounts of seafood with high MeHg levels can be considered at risk when consumption exceeds a certain amount. This level has been set by the WHO and other agencies, at 300 {mu}g/week of total mercury (totHg) of which there should be no more than 200 {mu}g as MeHg. The nervous system is the principal target of the effects of MeHg in humans. The most common functions affected are the sensory, visual and auditory functions, together with those of the cerebellum, which is concerned with coordination. As far as prenatal exposure is concerned, the developing central nervous system of humans and animals has been found to be more sensitive to damage from MeHg than the adult nervous system. This preliminary study obtains and examines information about eating habits and general health of a group of fisherman and their families living in a fishing village, at high risk because of the high frequency of seafood in their normal diet. 17 refs., 1 fig., 1 tab.

  11. Total mercury, methylmercury and ethylmercury in marine fish and marine fishery products sold in Seoul, Korea.

    PubMed

    Park, Ju-Sung; Jung, So-Young; Son, Yeo-Joon; Choi, Su-Jeong; Kim, Mi-Sun; Kim, Jeong-Gon; Park, So-Hyun; Lee, Sang-Me; Chae, Young-Zoo; Kim, Min-Young

    2011-01-01

    In 2009, a survey of 177 samples of fish and fishery products from the markets in Seoul was carried out to investigate total mercury and organic mercury (methylmercury) concentrations and to establish a correlation, if any, between total and organic mercury levels. Concentrations of total and organic mercury in canned tuna ranged 0.001-2.581 and 0.003-1.307 mg/kg, respectively; those for fish, such as cod or salmon, ranged 0.012-2.529 and 0.021-0.507 mg/kg, respectively. Ethylmercury was not detected. More than 50% of total mercury in the samples existed as organic mercury. The correlation coefficients (r(2)) between total mercury and methylmercury concentrations of fish and fishery products found to have methylmercury were 0.844 and 0.976, respectively, which was statistically significant. There was a higher correlation in fishery products than in fish. Although there was no product in which mercury exceeded the standard set by the Food Code in 2008, with the exception of marlin steak, a processed food, which contained 1.307 mg/kg methylmercury. None exceeded the provisional tolerable weekly intake (PTWI) for mercury. Collectively, the results indicate that fish or fishery products marketed in Seoul, with the exception of marlin, have low levels of total or organic mercury and, thus, intake of these products is not a risk to public health. PMID:24786250

  12. Hair care and dyeing.

    PubMed

    Draelos, Zoe Diana

    2015-01-01

    Alopecia can be effectively camouflaged or worsened through the use of hair care techniques and dyeing. Proper hair care, involving hair styling and the use of mild shampoos and body-building conditioners, can amplify thinning scalp hair; however, chemical processing, including hair dyeing, permanent waving, and hair straightening, can encourage further hair loss through breakage. Many patients suffering from alopecia attempt to improve their hair through extensive manipulation, which only increases problems. Frequent haircuts to minimize split ends, accompanied by gentle handling of the fragile fibers, is best. This chapter offers the dermatologist insight into hair care recommendations for the alopecia patient. PMID:26370650

  13. Hormetic effect of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J. Aschner, Michael

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis.

  14. Hormetic effect of methylmercury on Caenorhabditis elegans.

    PubMed

    Helmcke, Kirsten J; Aschner, Michael

    2010-10-15

    Research has demonstrated the toxic effects of methylmercury (MeHg), yet molecular mechanisms underlying its toxicity are not completely understood. Caenorhabditis elegans (C. elegans) offers a unique biological model to explore mechanisms of MeHg toxicity given many advantages associated with its ease of use and genetic power. Since our previous work indicated neurotoxic resistance of C. elegans to MeHg, the present study was designed to examine molecular mechanisms associated with this resistance. We hypothesized MeHg would induce expression of gst, hsp or mtl in vivo since glutathione (GSH), heat shock proteins (HSPs), and metallothioneins (MTs) have shown involvement in MeHg toxicity. Our studies demonstrated a modest, but significant increase in fluorescence in gst-4::GFP and mtl-1::GFP strains at an acute, low L1 MeHg exposure, whereas chronic L4 MeHg exposure induced expression of gst-4::GFP and hsp-4::GFP. Knockout gst-4 animals showed no alterations in lethality sensitivity compared to wildtype animals whereas mtl knockouts displayed increased sensitivity to MeHg exposure. GSH levels were increased by acute MeHg treatment and depleted with chronic exposure. We also demonstrate that MeHg induces hormesis, a phenotype whereby a sublethal exposure to MeHg rendered C. elegans resistant to subsequent exposure to the organometal. The involvement of gst-4, hsp-4, mtl-1, and mtl-2 in hormesis was examined. An increase in gst-4::GFP expression after a low-dose acute exposure to MeHg indicated that gst-4 may be involved in this response. Our results implicate GSH, HSPs, and MTs in protecting C. elegans from MeHg toxicity and show a potential role of gst-4 in MeHg-induced hormesis. PMID:20691719

  15. Hair follicle anatomy (image)

    MedlinePlus

    At the base of the hair follicle are sensory nerve fibers that wrap around each hair bulb. Bending the hair stimulates the nerve endings allowing a person to feel that the hair has been moved. One of the main functions of hair is to act ...

  16. Type and level of RMRP functional impairment predicts phenotype in the cartilage hair hypoplasia-anauxetic dysplasia spectrum.

    PubMed

    Thiel, Christian T; Mortier, Geert; Kaitila, Ilkka; Reis, André; Rauch, Anita

    2007-09-01

    Mutations in the RMRP gene lead to a wide spectrum of autosomal recessive skeletal dysplasias, ranging from the milder phenotypes metaphyseal dysplasia without hypotrichosis and cartilage hair hypoplasia (CHH) to the severe anauxetic dysplasia (AD). This clinical spectrum includes different degrees of short stature, hair hypoplasia, defective erythrogenesis, and immunodeficiency. The RMRP gene encodes the untranslated RNA component of the mitochondrial RNA-processing ribonuclease, RNase MRP. We recently demonstrated that mutations may affect both messenger RNA (mRNA) and ribosomal RNA (rRNA) cleavage and thus cell-cycle regulation and protein synthesis. To investigate the genotype-phenotype correlation, we analyzed the position and the functional effect of 13 mutations in patients with variable features of the CHH-AD spectrum. Those at the end of the spectrum include a novel patient with anauxetic dysplasia who was compound heterozygous for the null mutation g.254_263delCTCAGCGCGG and the mutation g.195C-->T, which was previously described in patients with milder phenotypes. Mapping of nucleotide conservation to the two-dimensional structure of the RMRP gene revealed that disease-causing mutations either affect evolutionarily conserved nucleotides or are likely to alter secondary structure through mispairing in stem regions. In vitro testing of RNase MRP multiprotein-specific mRNA and rRNA cleavage of different mutations revealed a strong correlation between the decrease in rRNA cleavage in ribosomal assembly and the degree of bone dysplasia, whereas reduced mRNA cleavage, and thus cell-cycle impairment, predicts the presence of hair hypoplasia, immunodeficiency, and hematological abnormalities and thus increased cancer risk. PMID:17701897

  17. Assessing and Managing Methylmercury Risks Associated With Power Plant Mercury Emissions in the United States

    PubMed Central

    Charnley, Gail

    2006-01-01

    Abstract and Introduction Abstract Until the Clean Air Mercury Rule was signed in March 2005, coal-fired electric utilities were the only remaining, unregulated major source of industrial mercury emissions in the United States. Proponents of coal-burning power plants assert that methylmercury is not a hazard at the current environmental levels, that current technologies for limiting emissions are unreliable, and that reducing mercury emissions from power plants in the United States will have little impact on environmental levels. Opponents of coal-burning plants assert that current methylmercury exposures from fish are damaging to the developing nervous system of infants, children, and the fetus; that current technology can significantly limit emissions; and that reducing emissions will reduce exposure and risk. One concern is that local mercury emissions from power plants may contribute to higher local exposure levels, or “hot spots.” The impact of the Mercury Rule on potential hot spots is uncertain due to the highly site-specific nature of the relationship between plant emissions and local fish methylmercury levels. The impact on the primary source of exposure in the United States, ocean fish, is likely to be negligible due to the contribution of natural sources and industrial sources outside the United States. Another debate centers on the toxic potency of methylmercury, with the scientific basis of the US Environmental Protection Agency's (EPA's) recommended exposure limit questioned by some and defended by others. It is likely that the EPA's exposure limit may be appropriate for combined exposure to methylmercury and polychlorinated biphenyls (PCBs), but may be lower than the available data suggest is necessary to protect children from methylmercury alone. Mercury emissions from power plants are a global problem. Without a global approach to developing and implementing clean coal technologies, limiting US power plant emissions alone will have little

  18. Porphyrins as biomarkers of methylmercury and PCB exposure in experimental quail

    SciTech Connect

    Leonzio, C.; Fossi, M.C.; Casini, S.

    1996-02-01

    Chemicals such as heavy metals and polyhalogenated hydrocarbons have a high capacity to interfere with the enzymatic processes responsible for haem biosynthesis. These compounds can produce accumulation in tissues and organs and increased elimination of porphyrins in excreta. The development of fast and easy analytical methods and the wide variety of biological media in which porphynins can be detected have suggested their use as biomarkers of environmental pollution. The analysis of porphynins in the excreta is of special interest because it enables non-destructive monitoring of wild animals in the assessment of threatened or endangered species. Methylmercury and PCBs are ubiquitous global pollutants and there is evidence they accumulate in ternfuinal consumers, particularly those belonging to marine trophic chain. There have been some reports on methylmercury-induced and PCB-induced porphyria but little data on their combined effect. In order to investigate the quality of porphyrins as biomarkers we performed an experiment in which Japanese quail were fed a diet containing methylmercury and polychlorobyphenyls (PCBs as Arochlor 1260) individually or combined in different ratios. The present study aims to provide preliminary data on liver and fecal levels of porphynins in response to methylmercury and PCB administration, and on whether the indicator is sensitive to synergism or antagonism between the two compounds, administered simultaneously.

  19. Classification models based on the level of metals in hair and nails of laryngeal cancer patients: diagnosis support or rather speculation?

    PubMed

    Golasik, Magdalena; Jawień, Wojciech; Przybyłowicz, Agnieszka; Szyfter, Witold; Herman, Małgorzata; Golusiński, Wojciech; Florek, Ewa; Piekoszewski, Wojciech

    2015-03-01

    The etiology of cancer is complex, and the disturbances in toxic and essential metals homeostasis are among many of the factors that lead to the development of malignancy. The aim of this study is to investigate the relationship between cancer risk and element status as well as cancer risk and external factors, such as diet, smoking and drinking habits, in order to support diagnosis of cancer. The samples of hair and nails obtained from patients with larynx cancer and healthy subjects were analyzed. Essential elements (Ca, Cr, Mg, Zn, Cu, Mn, and Fe), besides toxic metals (Cd, Co, and Pb), were determined using inductively coupled plasma atomic emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) techniques. The concentration of essential elements was from 1.5- (Zn) to 4.7-fold (Fe) higher in hair and from 2.4- to 3.3-fold higher in the nails of the control group compared to the patients, while the opposite trend was observed for the heavy metals. The differences between two groups in the level of metals (except for Zn) were statistically significant (p < 0.05). The association of cancer with metals and other factors was evaluated using various statistical methods, for which the best predictions were obtained using logistic regression, artificial neural networks and canonical discriminant analysis. The classifiers constructed using the data from a survey of diet and lifestyle, and analysis of elements in hair and nails, can be useful tools for estimating cancer risk and early screening of the disease. PMID:25616222

  20. Evaluation of Serum, Urine, and Hair Chromium Levels as Indices of Chromium Exposure and the Relationship of these Indices to Serum Lipid and Insulin Levels.

    NASA Astrophysics Data System (ADS)

    Randall, Janis Avril

    Concentrations of chromium (Cr) in hair, serum, and urine, and serum concentrations of insulin and lipids of a selected group of men exposed to trivalent Cr (Cr III) were compared with those of men not exposed to Cr. Seventy -three tannery workers (TW) (mean age 37 +/- 12 years) from four Southern Ontario tanneries and fifty-two control subjects (CS) (mean age 41 +/- 13 years), matched for age, race, and socioeconomic status, from the Guelph and Toronto areas participated. The median hair and serum Cr concentrations for the TW were significantly higher (p < 0.01) than for the CS (hair Cr 453 vs 124 ng/g; serum Cr 0.49 vs 0.15 ng/ml). Median urinary Cr/creatinine ratios (Cr/Cre) for the TW on Monday morning (0.83 ng/mg) and Friday afternoon (0.68 ng/mg) were also significantly higher (p < 0.01, p < 0.01, respectively) than the median urinary Cr/Cre ratio for the urine samples collected on a Friday afternoon from the CS (0.18 ng/mg). For the TW, the median Friday urinary Cr/Cre ratio was significantly higher (p = 0.03) than the corresponding Monday Cr/Cre ratio. For the TW, urinary Cr/Cre ratios (Monday and Friday) were correlated significantly and positively with both Cr concentrations in serum (r = 0.45, p < 0.01; r = 0.71, p < 0.01, respectively) and in hair (r = 0.43, p < 0.01; r = 0.64, p < 0.01, respectively). Concentrations of Cr in hair and in serum were also significantly correlated (r = 0.52, p < 0.01). There were no significant differences between the TW and CS in serum concentrations of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), or triglycerides, or in calculated values for low-density lipoprotein cholesterol, %HDL-C, and TC/HDL-C. Likewise, no significant differences in serum insulin concentrations were noted between the two groups. Results of this study indicate that Cr III, from compounds used in the leather tanning industry, is absorbed and retained. Absorption of Cr III had no significant effect on serum insulin

  1. Hair restoration surgery: the state of the art.

    PubMed

    Vogel, James E; Jimenez, Francisco; Cole, John; Keene, Sharon A; Harris, James A; Barrera, Alfonso; Rose, Paul T

    2013-01-01

    Hair restoration is a highly sophisticated subspecialty that offers significant relief to patients with hair loss. An improved understanding of the aesthetics of hair loss and cosmetic hair restoration, hair anatomy and physiology, and the development of microvascular surgical instrumentation has revolutionized the approach to surgical hair restoration since the original description. Additional elements that contribute to the current state of the art in hair restoration include graft size, site creation, packing density, and medical control of hair loss. The results of hair restoration are natural in appearance and are provided with a very high level of patient satisfaction and safety. This aspect of cosmetic surgery is a very welcome addition to a traditional aesthetic practice and serves as a tremendous source for internal cross-referral. The future of hair restoration surgery is centered on minimal-incision surgery as well as cell-based therapies. PMID:23169821

  2. Hair bleach poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002702.htm Hair bleach poisoning To use the sharing features on this page, please enable JavaScript. Hair bleach poisoning occurs when someone swallows hair bleach or ...

  3. Changing Your Hair

    MedlinePlus

    ... Snowboarding, Skating Crushes What's a Booger? Changing Your Hair KidsHealth > For Kids > Changing Your Hair Print A ... straight when it's curly. Treatments That Can Damage Hair Are these treatments OK for kids? That's something ...

  4. Hair spray poisoning

    MedlinePlus

    Hair spray poisoning occurs when someone breathes in (inhales) hair spray or sprays it down their throat or ... The harmful ingredients in hair spray are: Carboxymethylcellulose ... Polyvinyl alcohol Propylene glycol Polyvinylpyrrolidone

  5. Proteomic Analysis of Hair Follicles

    NASA Astrophysics Data System (ADS)

    Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

    2013-02-01

    Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

  6. Arsenic Exposure within the Korean Community (United States) Based on Dietary Behavior and Arsenic Levels in Hair, Urine, Air, and Water

    PubMed Central

    Cleland, Bill; Tsuchiya, Ami; Kalman, David A.; Dills, Russell; Burbacher, Thomas M.; White, Jim W.; Faustman, Elaine M.; Mariën, Koenraad

    2009-01-01

    Background Determining arsenic exposure in groups based on geographic location, dietary behaviors, or lifestyles is important, as even moderate exposures may lead to health concerns. Objectives/Methods The Korean community in Washington State, represents a group warranting investigation, as they consume foods (e.g., shellfish, rice, finfish, and seaweed) known to contain arsenic. As part of the Arsenic Mercury Intake Biometric Study, we examined the arsenic levels in hair and urine along with the diets of 108 women of childbearing age from within this community. Arsenic levels in indoor air and drinking water were also investigated, and shellfish commonly consumed were collected and analyzed for total and speciated arsenic. Results The six shellfish species analyzed (n = 667) contain total arsenic (range, 1–5 μg/g) but are a small source of inorganic arsenic (range, 0.01–0.12 μg/g). Six percent of the individuals may have elevated urinary inorganic arsenic levels (> 10 μg/L) due to diet. Seaweed, rice, shellfish, and finfish are principal sources for total arsenic intake/excretion based on mass balance estimates. Rice consumption (163 g/person/day) may be a significant source of inorganic arsenic. Air and water are not significant sources of exposure. Hair is a poor biometric for examining arsenic levels at low to moderate exposures. Conclusions We conclude that a portion of this community may have dietary inorganic arsenic exposure resulting in urine levels exceeding 10 μg/L. Although their exposure is below that associated with populations exposed to high levels of arsenic from drinking water (> 100 μg/L), their exposure may be among the highest in the United States. PMID:19440504

  7. Leptin of dermal adipose tissue is differentially expressed during the hair cycle and contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair.

    PubMed

    Yang, Chao-Chun; Sheu, Hamm-Ming; Chung, Pei-Lun; Chang, Chung-Hsing; Tsai, Yau-Sheng; Hughes, Michael W; Tuan, Tai-Lan; Huang, Lynn L H

    2015-01-01

    Adipose tissue encircles the lower portion of anagen hair follicles and may regulate hair cycle progression. As leptin is a major adipokine, its level of expression from the dermal white adipose tissue during hair cycle progression was studied. The result shows that leptin level is differentially expressed during hair cycle, the lowest in early anagen phase, upregulated in late anagen phase and the highest in the telogen phase. On the other hand, leptin receptor is detected in keratin 15-positive hair bulge epithelium of both anagen- and telogen-phase hair follicles of mice pelage and vibrissa hair, and hair from human scalp. Leptin contributes to adipocyte-mediated growth inhibition of anagen-phase vibrissa hair as demonstrated in organ culture and coculture system. Our data suggest that leptin of dermal white adipose tissue might regulate hair growth and, therefore, hair cycle progression via leptin receptor on the hair follicle epithelium. PMID:25313970

  8. Hair dye poisoning

    MedlinePlus

    Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

  9. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium.

    PubMed

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A C De; Debier, Cathy

    2016-08-01

    The polyunsaturated fatty acid (PUFA) composition of fish tissues, which generally reflects that of the diet, affects various cellular properties such as membrane structure and fluidity, energy metabolism and susceptibility to oxidative stress. Since these cellular parameters can play an important role in the cellular response to organic and inorganic pollutants, a variation of the PUFA supply might modify the toxicity induced by such xenobiotics. In this work, we investigated whether the cellular fatty acid profile has an impact on the in vitro cell sensitivity to two environmental pollutants: methylmercury and cadmium. Firstly, the fatty acid composition of the rainbow trout liver cell line RTL-W1 was modified by enriching the growth medium with either alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), linoleic acid (LA, 18:2n-6), arachidonic acid (AA, 20:4n-6) or docosapentaenoic acid (DPA, 22:5n-6). These modified cells and their control (no PUFA enrichment) were then challenged for 24h with increasing concentrations of methylmercury or cadmium. We observed that (i) the phospholipid composition of the RTL-W1 cells was profoundly modulated by changing the PUFA content of the growth medium: major modifications were a high incorporation of the supplemented PUFA in the cellular phospholipids, the appearance of direct elongation and desaturation metabolites in the cellular phospholipids as well as a change in the gross phospholipid composition (PUFA and monounsaturated fatty acid (MUFA) levels and n-3/n-6 ratio); (ii) ALA, EPA and DPA enrichment significantly protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in

  10. Increased Zn/Glutathione Levels and Higher Superoxide Dismutase-1 Activity as Biomarkers of Oxidative Stress in Women with Long-Term Dental Amalgam Fillings: Correlation between Mercury/Aluminium Levels (in Hair) and Antioxidant Systems in Plasma

    PubMed Central

    Cabaña-Muñoz, María Eugenia; Parmigiani-Izquierdo, José María; Bravo-González, Luis Alberto; Kyung, Hee-Moon; Merino, José Joaquín

    2015-01-01

    Background The induction of oxidative stress by Hg can affect antioxidant enzymes. However, epidemiological studies have failed to establish clear association between dental fillings presence and health problems. Objectives To determine whether heavy metals (in hair), antioxidant enzymes (SOD-1) and glutathione levels could be affected by the chronic presence of heavy metals in women who had dental amalgam fillings. Materials and Methods 55 hair samples (42 females with amalgam fillings and 13 female control subjects) were obtained. All subjects (mean age 44 years) who had dental amalgam filling for more than 10 years (average 15 years). Certain metals were quantified by ICP-MS (Mass Spectrophotometry) in hair (μg/g: Al, Hg, Ba, Ag, Sb, As, Be, Bi, Cd, Pb, Pt, Tl, Th, U, Ni, Sn, Ti) and SOD-1 and Glutathione (reduced form) levels in plasma. Data were compared with controls without amalgams, and analyzed to identify any significant relation between metals and the total number of amalgam fillings, comparing those with four or less (n = 27) with those with more than four (n = 15). As no significant differences were detected, the two groups were pooled (Amlgam; n = 42). Findings Hg, Ag, Al and Ba were higher in the amalgam group but without significant differences for most of the heavy metals analyzed. Increased SOD-1 activity and glutathione levels (reduced form) were observed in the amalgam group. Aluminum (Al) correlated with glutathione levels while Hg levels correlated with SOD-1. The observed Al/glutathione and Hg/SOD-1 correlation could be adaptive responses against the chronic presence of mercury. Conclusions Hg, Ag, Al and Ba levels increased in women who had dental amalgam fillings for long periods. Al correlated with glutathione, and Hg with SOD-1. SOD-1 may be a possible biomarker for assessing chronic Hg toxicity. PMID:26076368

  11. Understanding arsenic metabolism through a comparative study of arsenic levels in the urine, hair and fingernails of healthy volunteers from three unexposed ethnic groups in the United Kingdom

    SciTech Connect

    Brima, Eid I.; Haris, Parvez I. . E-mail: pharis@dmu.ac.uk; Jenkins, Richard O.; Polya, Dave A.; Gault, Andrew G.; Harrington, Chris F.

    2006-10-01

    Very little is known about arsenic (As) metabolism in healthy populations that are not exposed to high concentrations of As in their food or water. Here we present a study with healthy volunteers from three different ethnic groups, residing in Leicester, UK, which reveals statistically significant differences in the levels of total As in urine and fingernail samples. Urine (n = 63), hair (n = 36) and fingernail (n = 36) samples from Asians, Somali Black-Africans and Whites were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectroscopy (GF-AAS). The results clearly show that the total concentrations of As in urine and fingernail samples of a Somali Black-African population (urine 7.2 {mu}g/g creatinine; fingernails 723.1 {mu}g/kg) are significantly (P < 0.05) different from the Asian (urine 24.5 {mu}g/g creatinine; fingernails 153.9 {mu}g/kg) and White groups (urine 20.9 {mu}g/g creatinine; fingernails 177.0 {mu}g/kg). The chemical speciation of As in the urine of the three groups was also measured using high performance liquid chromatography coupled to ICP-MS. This showed that the proportion of the total urinary As present as dimethylarsenate (DMA) was higher for the Somali Black-African group (50%) compared to the Asians (16%) and Whites (22%). However, there was no significant difference (P > 0.05) in the level of As in the hair samples from these three groups; Somali Black-Africans (116.0 {mu}g/kg), Asians (117.4 {mu}g/kg) and Whites (141.2 {mu}g/kg). Significantly different levels of total As in fingernail and urine and a higher percentage of urinary DMA in the Somali Black-Africans are suggestive of a different pattern of As metabolism in this ethnic group.

  12. Abiotic production of methylmercury by solar radiation.

    PubMed

    Siciliano, Steven D; O'Driscoll, Nelson J; Tordon, Robert; Hill, Jonathan; Beauchamp, Stephen; Lean, David R S

    2005-02-15

    Methylmercury [MeHg(I) in the aerobic surface water of lakes is thought to be rapidly degraded, but contrary to expectations, we show that MeHg(I) concentrations often increase during sunlight hours or remain relatively constant. We hypothesized that there were water column processes that generated MeHg(I) and that these processes were linked to dissolved organic matter (DOM) and solar radiation. A 2-day diurnal pattern of MeHg(I) in surface water with corresponding bottled controls was assessed for two contrasting lakes in Kejimikujik, Nova Scotia, Canada. Following this study, a tangential ultrafiltrator was used to size-fractionate and generate a concentration gradient of DOM from four different lakes located near Lac Berthelot, Quebec, Canada. The watersheds of two of these lakes were not substantially logged whereas the other two had been extensively logged. Different size fractions of DOM as well as different concentrations of DOM were exposed to sunlight for varying periods of time. We observed that, in Keiimikujik, the concentration of MeHg(I) in surface waters peaked in the early afternoon. Furthermore, this also occurred in bottled water for one of the lakes, Puzzle, eliminating the possibility that in-lake mixing played a role in this pattern. The formation of MeHg(I) was found to be dependent on the size fraction and amount of DOM present in the water. Specifically, DOM less than 5 kDa or between 30 and 300 kDa generated MeHg(I) when exposed to sunlight, but larger fractions did not. Furthermore, although data are limited, we found that water from lakes with logged watersheds generated MeHg(I) when exposed to sunlight, whereas water from lakes with low levels of logging in the undisturbed watersheds did not. Our results demonstrate that MeHg(I) can be formed in freshwaters of certain lakes in response to solar radiation. This photoproduction of MeHg(I) is dependent on DOM concentrations and type, with the importance of water chemistry not yet clear. The

  13. Chronologically matched toenail-Hg to hair-Hg ratio: temporal analysis within the Japanese community (U.S.)

    PubMed Central

    2012-01-01

    Background Toenail-Hg levels are being used as a marker of methylmercury (MeHg) exposure in efforts to associate exposure with effects such as cardiovascular disease. There is a need to correlate this marker with more established biomarkers that presently underlie existing dose–response relationships in order to compare these relationships across studies. Methods As part of the Arsenic Mercury Intake Biometric Study, toenail clippings were collected at three time points over a period of one year amongst females from within the population of Japanese living near Puget Sound in Washington State (US). Variability in temporal intra-individual toenail-Hg levels was examined and chronologically matched hair and toenail samples were compared to more accurately define the toxicokinetic variability of Hg levels observed between the two compartments. Results Mean toenail-Hg values (n=43) for the 1st, 2nd and 3rd visits were 0.60, 0.60 and 0.56 ng/mg. Correlations were as follows: r=0.92 between 1st and 2nd clinic visits, r=0.75 between 1st and 3rd visits and r=0.87 between 2nd and 3rd visits. With few exceptions, toenail-Hg values from any visit were within 50-150% of the individual’s mean toenail-Hg level. Nearly all participants had less than a two-fold change in toenail-Hg levels across the study period. A regression model of the relationship between toenail-Hg and hair-Hg (n = 41) levels representing the same time period of exposure, gave a slope (Hg ng/mg) of 2.79 for hair relative to toenail (r=0.954). Conclusions A chronologically matched hair-Hg to toenail-Hg ratio has been identified within a population that consumes fish regularly and in quantity. Intra-individual variation in toenail-Hg levels was less than two-fold and may represent dietary-based fluctuations in body burden for individuals consuming various fish species with different contaminant levels. The chronologically matched ratio will be useful for relating MeHg exposure and dose–response derived

  14. Hair cosmetics: an overview.

    PubMed

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  15. Hair Cosmetics: An Overview

    PubMed Central

    Gavazzoni Dias, Maria Fernanda Reis

    2015-01-01

    Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

  16. Trace metal ions in hair from frequent hair dyers in China and the associated effects on photo-oxidative damage.

    PubMed

    Tang, Ying; Dyer, Jolon M; Deb-Choudhury, Santanu; Li, Qiao

    2016-03-01

    Human hairs are subject to oxidative modification when exposed to sunlight. In the present study, samples of human hair from Chinese volunteers that included frequent hair dyers and non-dyers were analyzed for metal ions such as iron, copper, magnesium, aluminum, zinc and lead. The generation of hydroxyl radicals during UVA (315-400 nm) photoageing was quantified and oxidative damages characterized by proteomic and SEM analysis. It was concluded that high levels of metal ions, particularly those derived from iron and copper, identified in the dyed hairs are associated with enhanced photoformation of hydroxyl radicals and resultant photooxidative damage of the hair. Reactive oxygen species, including hydroxyl radicals, generated via an electron transfer mechanism with hair photosensitizers react with hair proteins. Proteomic analysis of hair samples from frequent hair dyers, regardless of age and gender, showed an almost 1.6 fold increase in the protein oxidative modification levels compared to the undyed samples. As a result, a more pronounced physical damage including fragmentation and cross-linkage of cuticle scales was observed on the surface of dyed hair samples during the photoageing. This work is aimed at better understanding the role of metal ions in dyed hairs and their possible role in photosensitizing hair proteins. The results from this study are anticipated to contribute to the improved development of hair coloring cosmetics and hair care products. PMID:26803274

  17. Hair loss in women.

    PubMed

    Harfmann, Katya L; Bechtel, Mark A

    2015-03-01

    Hair loss is a common cause of morbidity for many women. As a key member of the woman's health care team, the obstetrician/gynecologist may be the first person to evaluate the complaint of hair loss. Common types of nonscarring hair loss, including female pattern hair loss and telogen effluvium, may be diagnosed and managed by the obstetrician/gynecologist. A systematic approach to diagnosis and management of these common forms of hair loss is presented. PMID:25517757

  18. Aging of hair.

    PubMed

    Trüeb, Ralph M

    2005-06-01

    The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life expectation, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and also more capable to deliver active products that are directed toward meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft and aging of the hair follicle. The latter manifests as decrease of melanocyte function or graying, and decrease in hair production in androgenetic and senescent alopecia. The scalp is also subject to intrinsic or physiologic aging and extrinsic aging caused by external factors. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation. Prototypes are familial premature graying and androgenetic alopecia. Extrinsic factors include ultraviolet radiation and smoking. Experimental evidence supports the hypothesis that oxidative stress plays a role in skin and hair aging. Topical anti-aging compounds for hair include humefactants, hair conditioners, photoprotectors, and antioxidants. Current available treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil, oral finasteride, and autologous hair transplantation. In the absence of another way to reverse hair graying, hair colorants are the mainstays of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are under current investigation. PMID:17166201

  19. Splitting hair for cortisol? Associations of socio-economic status, ethnicity, hair color, gender and other child characteristics with hair cortisol and cortisone.

    PubMed

    Rippe, Ralph C A; Noppe, Gerard; Windhorst, Dafna A; Tiemeier, Henning; van Rossum, Elisabeth F C; Jaddoe, Vincent W V; Verhulst, Frank C; Bakermans-Kranenburg, Marian J; van IJzendoorn, Marinus H; van den Akker, Erica L T

    2016-04-01

    The aim of this study was to examine associations of SES and ethnicity with hair cortisol and cortisone and to identify potential child and family characteristics that can assist in choosing covariates and potential confounders for analyses involving hair cortisol and cortisone concentrations. Hair samples were collected in 2484 6-year-old children from the Generation R Study, a prospective cohort in Rotterdam, the Netherlands. Measurements for cortisol and cortisone were used as the outcome in regression analyses. Predictors were SES, ethnicity, hair color and child characteristics such as birthweight, gestational age at birth, BMI, disease, allergy, and medication use. Lower family income, more children to be supported by this income, higher BMI and darker hair color were associated with higher hair cortisol and cortisone levels. Boys also showed higher levels. Ethnicity (Dutch and North European descent) was related to lower levels. High amounts of sun in the month of hair collection was related to higher levels of cortisone only. More recent hair washing was related to lower levels of cortisol and cortisone. Gestational age at birth, birth weight, age, medication use, hair washing frequency, educational level of the mother, marital status of the mother, disease and allergy were not associated with cortisol or cortisone levels. Our results serve as a starting point for choosing covariates and confounders in studies of substantive predictors or outcomes. Gender, BMI, income, the number of persons in a household, ethnicity, hair color and recency of hair washing are strongly suggested to take into account. PMID:26773401

  20. Effect of methylmercury on acetylcholinestrase and serum cholinesterase activity in monkeys, Macaca fascicularis

    SciTech Connect

    Petruccioli, L.; Turillazzi, P.G. )

    1991-05-01

    The consumption of fish and fish-derived products is the main pathway of human exposure to methylmercury (MeHg). Methylmercury levels vary widely in fish, depending on age, size, the position of the species in the food chain, and most of all, on pollution levels. MeHg affects the Acetylcholinesterase activity (AChE) and the serum Cholinesterase activity (BChE). Histoenzymatic studies showed that 100mg Methyoxyethylmercury chloride administered for 6 days to rats caused a reduction of AChE activity in the thalamus and an increase in different parts of the nervous central system. The present study aims at verifying whether the dose permitted by F.A.O. and doses 10 and 100 fold higher affect the Cholinesterase activity in primates, and whether there is a correlation between AChE and BChE.

  1. Effects of Maternally-Transferred Methylmercury on Stress Physiology in Northern Water Snake (Nerodia sipedon) Neonates.

    PubMed

    Cusaac, J Patrick W; Kremer, Victoria; Wright, Raymond; Henry, Cassandra; Otter, Ryan R; Bailey, Frank C

    2016-06-01

    Biomagnification of methylmercury in aquatic systems can cause elevated tissue mercury (Hg) and physiological stress in top predators. Mercury is known to affect stress hormone levels in mammals, birds and fish. In this study, the effects of maternally-transferred methylmercury on the stress physiology of Northern Water Snake (Nerodia sipedon) neonates were tested. Gravid females were dosed via force-fed capsules during late gestation with 0, 0.01, or 10 µg methylmercury per gram of body mass. Plasma corticosterone levels and leukocyte differentials were analyzed in baseline and confinement-stressed neonates from all dose levels. Neither Hg nor confinement stress had a significant effect on leukocyte differentials nor was Hg related to corticosterone levels. However, stress group neonates showed lower heterophil/lymphocyte ratios and this study was the first to show that neonate N. sipedon can upregulate CORT in response to stress. These results indicate that N. sipedon may be somewhat tolerant to Hg contamination. PMID:26886428

  2. Neurotoxicity of lead, methylmercury, and PCBs in relation to the Great Lakes.

    PubMed Central

    Rice, D C

    1995-01-01

    There is ample evidence identifying lead, methylmercury, and polychlorinated biphenyls (PCBs) as neurotoxic agents. A large body of data on the neurotoxicity of lead, based on both epidemiologic studies in children and animal models of developmental exposure, reveals that body burdens of lead typical of people in industrialized environments produce behavioral impairment. Methylmercury was identified as a neurotoxicant in both adults and the developing organism based on episodes of human poisoning: these effects have been replicated and extended in animals. High-dose PCB exposure was recognized as a developmental toxicant as a result of several episodes of contamination of cooking oil. The threshold for PCB neurotoxicity in humans is less clear, although research in animals suggests that relatively low-level exposure produces behavioral impairment and other toxic effects. Tissue levels in fish below which human health would not be adversely affected were estimated for methylmercury and PCBs based on calculated reference doses (RfDs) and estimated fish intake. Present levels in fish tissue in the Great Lakes exceed these levels for both neurotoxicants. Great Lakes fish and water do not pose a particular hazard for increased lead intake. However, the fact that the present human body burden is in a range at which functional deficits are probable suggests that efforts should be made to eliminate point sources of lead contamination in the Great Lakes basin. PMID:8635443

  3. Possible physiological uptake mechanism of methylmercury by the marine bloodworm (Glycera dibranchiata)

    SciTech Connect

    Medeiros, D.M.; Cadwell, L.L.; Preston, R.L.

    1980-01-01

    The uptake of methylmercury by fish has been studied extensively. There have been some studies on marine invertebrates. These studies have been concerned with either the effect of methylmercury on viability or methylmercury distribution among body parts. The physiological uptake mechanisms of methylmercury in aquatic organisms have not been studied. The objective of this paper is to examine the uptake mechanism of methylmercury from water in a lower-food-chain organism, the marine bloodworm (Glycera dibranchi-ata).

  4. Blood pressure and levels of Fe, Ca, Mg, Zn, Cu, Na and K in the hair of young Bantu men from Tanzania.

    PubMed

    Rębacz-Maron, Ewa; Baranowska-Bosiacka, Irena; Gutowska, Izabela; Chlubek, Dariusz

    2013-03-01

    Mineral imbalance in the body may significantly contribute to the development and course of hypertension. In this paper, blood pressure figures have been linked to the levels of Fe, Ca, Mg, Zn, Cu, Na and K in hair. The research sample was composed of young men (n = 91) aged 13-21, from the town of Mafinga, Iringa District, Tanzania. The data collected included their age, tribal background and weekly diet. Based on body mass index, the participants were categorised into pre-defined subgroups. To examine how the minerals in question affect blood pressure, correlation analysis and multiple ridge regression analysis were performed. Analysis of ridge regression findings for the researched group (n = 91) shows that the minerals under scrutiny account for systolic blood pressure variation in 13 % and in 15 % for diastolic blood pressure variation. After including two additional variables-calendar age and body mass index-in regression analysis, the ultimate coefficient of determination (R (2)) changes for systolic blood pressure and remains the same for diastolic blood pressure (R (2) = 0.194 and R (2) = 0.156, respectively). Nutritional analysis shows that the students included in the study received insufficient calories per day (1,500-2,200 kcal). The group of students with abnormal blood pressure were not aware of their poor health. Research findings may result from progressive environmental changes and poor nutrition in terms of food quantity and quality, which had an impact on the subjects' blood pressure. Hair analysis used to determine mineral content in the body may be an auxiliary tool in identifying the links between factors leading to the development of hypertension. PMID:23279941

  5. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood

    SciTech Connect

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N.; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M.

    2011-11-15

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD + opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 {mu}g/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. -- Highlights: Black-Right-Pointing-Pointer Exposure to pesticides and organic solvents might be a risk factor for sporadic MND. Black-Right-Pointing-Pointer We report a patient who developed progressive upper and lower motor neuron disease. Black-Right-Pointing-Pointer The patient had a history of occupational exposure to pesticides and solvents. Black-Right-Pointing-Pointer High DDTs' levels and increased levels of DMP and DEP were measured in his hair. Black-Right-Pointing-Pointer The patients' exposure to chemicals might have played

  6. Methylmercury-mediated inhibition of 3H-D-aspartate transport in cultured astrocytes is reversed by the antioxidant catalase.

    PubMed

    Allen, J W; Mutkus, L A; Aschner, M

    2001-05-25

    Astrocytes are essential for removal of glutamate from the extracellular space in the central nervous system. The neurotoxic heavy metal methylmercury potently and specifically inhibits the transport of glutamate in cultured astrocytes by an unknown mechanism. Glutamate transport in astrocytes is also inhibited by reactive oxygen species. A glutamate-induced transporter current is inhibited both by reactive oxygen species and thiol oxidizing agents. These observations suggest that oxidation of the transporter might mediate methylmercury-induced inhibition of glutamate transport. In the present study, we examined the ability of thiol reducing or oxidizing agents to inhibit transport of 3H-D-aspartate, a glutamate analog, in primary cultures of neonatal rat astrocytes. To assess if methylmercury-mediated inhibition of 3H-aspartate transport was due to overproduction of reactive oxygen species, we tested the ability of Trolox, alpha-phenyl-tert-butyl nitrone (PBN), or catalase to attenuate the methylmercury-induced inhibition of aspartate uptake. Neither the thiol reducing agent dithiothreitol (DTT), nor the thiol oxidizing agent 5,5'-dithio-bis(2-nitrobenzoic) acid (DTNB) had any effect on 3H-aspartate transport suggesting that the thiol redox state does not alter transporter function. In contrast, the antioxidant catalase (1000 U/ml) significantly attenuated methylmercury-induced inhibition of 3H-aspartate uptake, suggesting that excess reactive oxygen species, specifically H2O2, inhibit the function of an astrocytic excitatory amino acid transporter (EAAT1). Prolonged exposure (6 h) to inhibitors of glutamate transport significantly decreased EAAT1 mRNA levels suggesting that transporter expression is related to function. This study suggests that methylmercury-induced overproduction of H2O2 is a mechanism for inhibition of glutamate transport and transporter expression in cultured astrocytes. PMID:11376598

  7. New trichoscopy findings in trichotillomania: flame hairs, V-sign, hook hairs, hair powder, tulip hairs.

    PubMed

    Rakowska, Adriana; Slowinska, Monika; Olszewska, Malgorzata; Rudnicka, Lidia

    2014-05-01

    Differential diagnosis of trichotillomania is often difficult in clinical practice. Trichoscopy (hair and scalp dermoscopy) effectively supports differential diagnosis of various hair and scalp diseases. The aim of this study was to assess the usefulness of trichoscopy in diagnosing trichotillomania. The study included 370 patients (44 with trichotillomania, 314 with alopecia areata and 12 with tinea capitis). Statistical analysis revealed that the main and most characteristic trichoscopic findings of trichotillomania are: irregularly broken hairs (44/44; 100% of patients), v-sign (24/44; 57%), flame hairs (11/44; 25%), hair powder (7/44; 16%) and coiled hairs (17/44; 39%). Flame hairs, v-sign, tulip hairs, and hair powder were newly identified in this study. In conclusion, we describe here specific trichoscopy features, which may be applied in quick, non-invasive, in-office differential diagnosis of trichotillomania. PMID:24096547

  8. Potentiation of Methylmercury-Induced Death in Rat Cerebellar Granular Neurons Occurs by Further Decrease of Total Intracellular GSH with BDNF via TrkB in Vitro.

    PubMed

    Sakaue, Motoharu; Maki, Takehiro; Kaneko, Takuya; Hemmi, Natsuko; Sekiguchi, Hitomi; Horio, Tomoyo; Kadowaki, Erina; Ozawa, Aisa; Yamamoto, Masako

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) is a principal factor for neurogenesis, neurodevelopment and neural survival through a BDNF receptor, tropomyosin-related kinase (Trk) B, while BDNF can also cause a decrease in the intracellular glutathione (GSH) level. We investigated the exacerbation of methylmercury-induced death of rat cerebellar granular neurons (CGNs) by BDNF in vitro. Since methylmercury can decrease intracellular GSH levels, we hypothesized that a further decrease of the intracellular GSH level is involved in the process of the exacerbation of neuronal cell death. In the present study, we established that in CGN culture, a decrease of the intracellular GSH level was further potentiated with BDNF in the process of the methylmercury-induced neuronal death and also in GSH reducer-induced neuronal death. BDNF treatment promoted the decrease in GSH levels induced by methylmercury and also by L-buthionine sulfoximine (BSO) and diethyl maleate (DEM). The promoting effect of BDNF was observed in a TrkB-vector transformant of the rat neuroblastoma B35 cell line but not in the mock-vector transformant. These results indicate that the exacerbating effect of BDNF on methylmercury-induced neuronal death in cultures of CGNs includes a further decrease of intracellular GSH levels, for which TrkB is essential. PMID:27251509

  9. Chemical processing and shampooing impact cortisol measured in human hair

    PubMed Central

    Hoffman, M. Camille; Karban, Laura V.; Benitez, Patrick; Goodteacher, Angela; Laudenslager, Mark L.

    2015-01-01

    Purpose The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. Methods Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. Results Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. Conclusion Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies. PMID:25090265

  10. Perinatal and lifetime exposure to methylmercury in the mouse: behavioral effects.

    PubMed

    Weiss, Bernard; Stern, Sander; Cox, Christopher; Balys, Marlene

    2005-08-01

    This project was undertaken to more completely understand the consequences of lifetime exposure to methylmercury. A series of experiments examined how perinatal or lifetime exposure to methylmercury affected behavioral performances in the adult mouse at different ages. One hundred female B6C3F1/HSD mice were assigned to one of three dose groups, 0 ppm, 1 ppm, or 3 ppm methylmercury chloride administered in a 5 nM sodium carbonate drinking solution. Four weeks after initiating dosing, the females were bred with male CBA/J HSD mice to produce the trihybrid offspring B6C3F1/HSD x CBA/J HSD. The methylmercury-treated litters were split into two subgroups, one exposed throughout its lifetime to the original dose, the other exposed through postnatal day 13. Altogether, then, five groups were studied: Control, 1 ppm perinatal, 1 ppm lifetime, 3 ppm perinatal, and 3 ppm lifetime. Three neurobehavioral indices were evaluated: (1) delayed spatial alternation (a test of memory) and (2) running in a wheel to earn food pellets (schedule-controlled operant behavior) were assessed starting at 5 and 15 months of age; (3) hindlimb splay, a measure of motor function, was assessed at 5, 15, and 26 months of age. Subjects tested at one age were littermates of those tested at the other ages. MeHg altered the hindlimb splay distance; control mice differed from methylmercury-exposed mice, the 1 ppm lifetime and 3 ppm lifetime groups differed from each other, and the analysis yielded an age by dose interaction. MeHg exposure altered different measures of wheel running under the 3 ppm lifetime condition. In the delayed alternation procedure, the mouse was required to respond to one of two locations in a strictly alternating sequence. More mice from the treated groups, except for the 1 ppm perinatal group, failed to meet the criterion at longer delay values. Overall, the results show that exposure to low levels of methylmercury produces behavioral effects that depend on the test procedure

  11. Beam shaping for cosmetic hair removal

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.; Tuttle, Tracie

    2007-09-01

    Beam shaping has the potential to provide comfort to people who require or seek laser based cosmetic skin procedures. Of immediate interest is the procedure of aesthetic hair removal. Hair removal is performed using a variety of wavelengths from 480 to 1200 nm by means of filtered Xenon flash lamps (pulsed light) or 810 nm diode lasers. These wavelengths are considered the most efficient means available for hair removal applications, but current systems use simple reflector designs and plane filter windows to direct the light to the surface being exposed. Laser hair removal is achieved when these wavelengths at sufficient energy levels are applied to the epidermis. The laser energy is absorbed by the melanin (pigment) in the hair and hair follicle which in turn is transformed into heat. This heat creates the coagulation process, which causes the removal of the hair and prevents growth of new hair [1]. This paper outlines a technique of beam shaping that can be applied to a non-contact based hair removal system. Several features of the beam shaping technique including beam uniformity and heat dispersion across its operational treatment area will be analyzed. A beam shaper design and its fundamental testing will be discussed in detail.

  12. Improved biolistic transfection of hair cells.

    PubMed

    Zhao, Hongyu; Avenarius, Matthew R; Gillespie, Peter G

    2012-01-01

    Transient transfection of hair cells has proven challenging. Here we describe modifications to the Bio-Rad Helios Gene Gun that, along with an optimized protocol, improve transfection of bullfrog, chick, and mouse hair cells. The increased penetrating power afforded by our method allowed us to transfect mouse hair cells from the basal side, through the basilar membrane; this configuration protects hair bundles from damage during the procedure. We characterized the efficiency of transfection of mouse hair cells with fluorescently-tagged actin fusion protein using both the optimized procedure and a published procedure; while the efficiency of the two methods was similar, the morphology of transfected hair cells was improved with the new procedure. In addition, using the improved method, we were able to transfect hair cells in the bullfrog sacculus and chick cochlea for the first time. We used fluorescent-protein fusions of harmonin b (USH1C) and PMCA2 (ATP2B2; plasma-membrane Ca(2+)-ATPase isoform 2) to examine protein distribution in hair cells. While PMCA2-EGFP localization was similar to endogenous PMCA2 detected with antibodies, high levels of harmonin-EGFP were found at stereocilia tapers in bullfrog and chick, but not mouse; by contrast, harmonin-EGFP was concentrated in stereocilia tips in mouse hair cells. PMID:23049715

  13. Improved Biolistic Transfection of Hair Cells

    PubMed Central

    Gillespie, Peter G.

    2012-01-01

    Transient transfection of hair cells has proven challenging. Here we describe modifications to the Bio-Rad Helios Gene Gun that, along with an optimized protocol, improve transfection of bullfrog, chick, and mouse hair cells. The increased penetrating power afforded by our method allowed us to transfect mouse hair cells from the basal side, through the basilar membrane; this configuration protects hair bundles from damage during the procedure. We characterized the efficiency of transfection of mouse hair cells with fluorescently-tagged actin fusion protein using both the optimized procedure and a published procedure; while the efficiency of the two methods was similar, the morphology of transfected hair cells was improved with the new procedure. In addition, using the improved method, we were able to transfect hair cells in the bullfrog sacculus and chick cochlea for the first time. We used fluorescent-protein fusions of harmonin b (USH1C) and PMCA2 (ATP2B2; plasma-membrane Ca2+-ATPase isoform 2) to examine protein distribution in hair cells. While PMCA2-EGFP localization was similar to endogenous PMCA2 detected with antibodies, high levels of harmonin-EGFP were found at stereocilia tapers in bullfrog and chick, but not mouse; by contrast, harmonin-EGFP was concentrated in stereocilia tips in mouse hair cells. PMID:23049715

  14. Liver mercury and methylmercury concentrations in New England common loons (Gavia immer)

    SciTech Connect

    Pokras, M.A.; Hanley, C.; Gordon, Z.

    1998-02-01

    Loons are of special interest to environmental scientists, who see them as a sentinel species for environmental health. This bird is a top predator in both fresh- and saltwater environments. A number of studies have been published regarding contaminant-related loon pathology, and they have repeatedly found Hg contamination and ingestion of lead fishing gear to be of particular concern. Since 1989 the authors have been studying regional patterns of loon mortality and have examined more than 400 birds. One segment of this study has been to document contaminants found in loons and to attempt to associate health effects with these contaminants. This article details some of their work on Hg in loons. Liver samples collected from common loons found dead were analyzed for mercury and methylmercury concentrations. Statistical analyses demonstrated no correlation between total mercury and methylmercury levels.

  15. A case report of motor neuron disease in a patient showing significant level of DDTs, HCHs and organophosphate metabolites in hair as well as levels of hexane and toluene in blood.

    PubMed

    Kanavouras, Konstantinos; Tzatzarakis, Manolis N; Mastorodemos, Vasileios; Plaitakis, Andreas; Tsatsakis, Aristidis M

    2011-11-01

    Motor neuron disease is a devastating neurodegenerative condition, with the majority of sporadic, non-familial cases being of unknown etiology. Several epidemiological studies have suggested that occupational exposure to chemicals may be associated with disease pathogenesis. We report the case of a patient developing progressive motor neuron disease, who was chronically exposed to pesticides and organic solvents. The patient presented with leg spasticity and developed gradually clinical signs suggestive of amyotrophic lateral sclerosis, which was supported by the neurophysiologic and radiological findings. Our report is an evidence based case of combined exposure to organochlorine (DDTs), organophosphate pesticides (OPs) and organic solvents as confirmed by laboratory analysis in samples of blood and hair confirming systematic exposure. The concentration of non-specific dialkylphosphates metabolites (DAPs) of OPs in hair (dimethyphopshate (DMP) 1289.4 pg/mg and diethylphosphate (DEP) 709.4 pg/mg) and of DDTs (opDDE 484.0 pg/mg, ppDDE 526.6 pg/mg, opDDD 448.4 pg/mg, ppDDD+opDDT 259.9 pg/mg and ppDDT 573.7 pg/mg) were considerably significant. Toluene and n-hexane were also detected in blood on admission at hospital and quantified (1.23 and 0.87 μg/l, respectively), while 3 months after hospitalization blood testing was found negative for toluene and n-hexane and hair analysis was provided decrease levels of HCHs, DDTs and DAPs. PMID:21851830

  16. Behavioral teratology of methylmercury in fish

    SciTech Connect

    Weis, P.; Weis, J.S.

    1994-12-31

    Embryos of the mummichog, Fundulus heteroclitus, were exposed to 2, 5, or 10 ug/l methylmercury throughout development. These are concentrations below those that can cause teratological effects. After hatching, larvae were maintained in clean sea water and tested for prey capture ability, using Artemia nauplii as prey. Individual fish larvae were provided with five brine shrimp and their capture times recorded. In all experiments, larvae that had been exposed to 10 ug/l methylmercury initially exhibited slower prey capture ability than the other groups. This is an indication of a subtle functional impairment due to the toxicant (``behavioral teratology``). However, the effect was transitory, and by about one week after hatching the prey capture of these larvae equaled that of the controls and the other treated groups. Growth of these larvae also equaled that of controls and the other groups. The embryonic exposure may have caused retardation of neurological development, which was subsequently compensated for, and therefore no permanent effects were produced. In the field, however, embryos exposed to such toxicants would probably continue to be exposed as larvae, and would not have the opportunity to recover from the effects, but rather might have them reinforced.

  17. Patients treated for male pattern hair with finasteride show, after discontinuation of the drug, altered levels of neuroactive steroids in cerebrospinal fluid and plasma.

    PubMed

    Caruso, Donatella; Abbiati, Federico; Giatti, Silvia; Romano, Simone; Fusco, Letizia; Cavaletti, Guido; Melcangi, Roberto Cosimo

    2015-02-01

    Observations performed in a subset of patients treated for male pattern hair loss indicate that persistent sexual side effects as well as anxious/depressive symptomatology have been reported even after discontinuation of finasteride treatment. Due to the capability of finasteride to block the metabolism of progesterone (PROG) and/or testosterone (T) we have evaluated, by liquid chromatography-tandem mass spectrometry, the levels of several neuroactive steroids in paired plasma and cerebrospinal fluid (CSF) samples obtained from post-finasteride patients and in healthy controls. At the examination, post-finasteride patients reported muscular stiffness, cramps, tremors and chronic fatigue in the absence of clinical evidence of any muscular disorder or strength reduction. Although severity of the anxious/depressive symptoms was quite variable in their frequency, overall all the subjects had a fairly complex and constant neuropsychiatric pattern. Assessment of neuroactive steroid levels in CSF showed a decrease of PROG and its metabolites, dihydroprogesterone (DHP) and tetrahydroprogesterone (THP), associated with an increase of its precursor pregnenolone (PREG). Altered levels were also observed for T and its metabolites. Thus, a significant decrease of dihydrotestosterone (DHT) associated with an increase of T as well as of 3α-diol was detected. Changes in neuroactive steroid levels also occurred in plasma. An increase of PREG, T, 3α-diol, 3β-diol and 17β-estradiol was associated with decreased levels of DHP and THP. The present observations show that altered levels of neuroactive steroids, associated with depression symptoms, are present in androgenic alopecia patients even after discontinuation of the finasteride treatment. This article is part of a Special Issue entitled 'Sex steroids and brain disorders'. PMID:24717976

  18. Hair loss in women.

    PubMed

    Camacho-Martínez, Francisco M

    2009-03-01

    Female pattern hair loss (FPHL) is a clinical problem that is becoming more common in women. Female alopecia with androgen increase is called female androgenetic alopecia (FAGA) and without androgen increase is called female pattern hair loss. The clinical picture of typical FAGA begins with a specific "diffuse loss of hair from the parietal or frontovertical areas with an intact frontal hairline." Ludwig called this process "rarefaction." In Ludwig's classification of hair loss in women, progressive type of FAGA, 3 patterns were described: grade I or minimal, grade II or moderate, and grade III or severe. Ludwig also described female androgenetic alopecia with male pattern (FAGA.M) that should be subclassified according to Ebling's or Hamilton-Norwood's classification. FAGA.M may be present in 4 conditions: persistent adrenarche syndrome, alopecia caused by an adrenal or an ovarian tumor, posthysterectomy, and as an involutive alopecia. A more recent classification (Olsen's classification of FPHL) proposes 2 types: early- and late-onset with or without excess of androgens in each. The diagnosis of FPHL is made by clinical history, clinical examination, wash test, dermoscopy, trichoscan, trichograms and laboratory test, especially androgenic determinations. Topical treatment of FPHL is with minoxidil, 2-5% twice daily. When FPHL is associated with high levels of androgens, systemic antiandrogenic therapy is needed. Persistent adrenarche syndrome (adrenal SAHA) and alopecia of adrenal hyperandrogenism is treated with adrenal suppression and antiandrogens. Adrenal suppression is achieved with glucocorticosteroids. Antiandrogens therapy includes cyproterone acetate, drospirenone, spironolactone, flutamide, and finasteride. Excess release of ovarian androgens (ovarian SAHA) and alopecia of ovarian hyperandrogenism is treated with ovarian suppression and antiandrogens. Ovarian suppression includes the use of contraceptives containing an estrogen, ethinylestradiol, and a

  19. Replacing facial hair.

    PubMed

    Straub, Paul M

    2008-11-01

    The face is the second most common area for hair transplantation after the scalp. Areas that are transplanted include eyebrows, eyelashes, moustaches, beards, temples and temporal points, as well as scars either traumatic or the side effect of cosmetic procedures such as rhytidectomies or brow lifts. The hair is harvested from the same area as the hair that is transplanted to the head. For this reason, it grows longer than nongrafted facial hair and must be trimmed regularly. Occasionally, hair lower in the neck region is harvested, which is finer than occipital hair; however, because of movement in the neck area, the scars are often larger. Body hair has been suggested as donor hair but is not recommended because it spends as much as 85% of its time in the telogen phase. PMID:19034820

  20. Hitchhiking women's hair color.

    PubMed

    Guéguen, Nicolas; Lamy, Lubomir

    2009-12-01

    To test the effect of women's hair color on the frequency of offering help, male (n = 1,508) and female (n = 892) French motorists were tested in a hitchhiking situation. Five 20- to 22- yr.-old female confederates wore a wig with blonde, brown, or black hair. Each confederate was instructed to stand by the side of a road frequented by hitchhikers and hold out her thumb to catch a ride. Blonde hair, compared with brown hair or black hair, was associated with a small but significantly larger number of male drivers who stopped to offer a ride (18 vs 14%). No difference was found for those with brown and black hair (14 and 13%, respectively). No effect of hair color was found for female drivers who stopped. The greater attractiveness associated with blonde hair for women appears to explain these data. PMID:20178293

  1. Forensic Science: Hair Identification.

    ERIC Educational Resources Information Center

    Keller, Elhannan L.

    1980-01-01

    Presented is an activity in which students use a microscope to do a forensic hair comparative study and a medullary classification. Mounting methods, medulla types, hair photographs, and activities are described. (DS)

  2. Hair straightener poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

  3. Skin, Hair, and Nails

    MedlinePlus

    ... special types of cells: Melanocytes produce melanin, the pigment that gives skin its color. All people have ... the epidermis). Hair also contains a yellow-red pigment; people who have blonde or red hair have ...

  4. The levels of mercury, methylmercury and selenium and the selenium health benefit value in grey-eel catfish (Plotosus canius) and giant mudskipper (Periophthalmodon schlosseri) from the Strait of Malacca.

    PubMed

    Looi, Ley Juen; Aris, Ahmad Zaharin; Haris, Hazzeman; Yusoff, Fatimah Md; Hashim, Zailina

    2016-06-01

    The present study examined the concentrations of mercury (Hg), methylmercury (MeHg), and selenium (Se) in the multiple tissues of the Plotosus canius and Periophthalmodon schlosseri collected from the Strait of Malacca. The mean value in mg kg(-1) of Hg (P. canius: 0.34 ± 0.19; P. schlosseri: 0.32 ± 0.18) and MeHg in muscle (P. canius: 0.14 ± 0.11; P. schlosseri: 0.17 ± 0.11) were below the Codex general standard for contaminants and toxins in food and feed (CODEX STAN 193-1995), the Malaysian Food Regulation 1985 and the Japan Food Sanitation Law. For P. canius, the liver contained the highest concentrations of Hg (0.48 ± 0.07 mg kg(-1)) and MeHg (0.21 ± 0.00 mg kg(-1)), whereas for P. schlosseri, the gill contained the highest concentrations of Hg (0.36 ± 0.06 mg kg(-1)) and MeHg (0.21 ± 0.05 mg kg(-1)). The highest concentration of (80)Se (mg kg(-1)) was observed in the liver of P. canius (20.34 ± 5.68) and in the gastrointestinal tract (3.18 ± 0.42) of P. schlosseri. The selenium:mercury (Se:Hg) molar ratios were above 1 and the positive selenium health benefit value (HBVSe) suggesting the possible protective effects of Se against Hg toxicity. The estimate weekly intakes (EWIs) in μg kg(-1) body weight (bw) week(-1) of Hg (P. canius: 0.27; P. schlosseri: 0.15) and MeHg (P. canius: 0.11; P. schlosseri: 0.08) were found to be lower than the provisional tolerable weekly intake established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Based on the calculated EWIs, P. canius, and P. schlosseri were found to be unlikely to cause mercury toxicity in human consumption. PMID:26974481

  5. Work stress and hair cortisol levels among workers in a Bangladeshi ready-made garment factory - Results from a cross-sectional study.

    PubMed

    Steinisch, Maria; Yusuf, Rita; Li, Jian; Stalder, Tobias; Bosch, Jos A; Rahman, Omar; Strümpell, Christian; Ashraf, Hasan; Fischer, Joachim E; Loerbroks, Adrian

    2014-12-01

    Evidence on the association of work stress with cortisol levels is inconsistent and mostly stems from Western countries, with limited generalizability to other regions of the world. These inconsistencies may partly be due to methodological limitations associated with the measurement of cortisol secretion in saliva, serum or urine. The present study set out to explore associations of work stress with long-term integrated cortisol levels in hair among 175 workers of an export oriented ready-made garment (RMG) factory in Dhaka, Bangladesh. Work-related demands (WD), interpersonal resources (IR) and work-related values (WV) were assessed using a psychometrically evaluated interview. WD consisted of four items on physical demands, time pressure, worries about mistakes and exposure to abusive language. IR comprised five items addressing support, recognition, adequate payment, workers' trust in the management, and the management's trust in workers, as perceived by the workers. WV captured job security, promotion prospects and job latitude by three items. Hair cortisol concentrations (HCC) were analyzed by liquid chromatography-mass spectrometry. Stepwise multivariable linear regression models (backward elimination of predictors) were used to estimate associations of HCC with the three work stress components. For significant work stress component(s), further multivariable linear regression analyses were conducted to explore whether, and if so, which individual item(s) contributed most. The mean HCC equaled 3.27 (SD 2.58) pg/mg. HCC were found to be significantly associated with WV (beta=0.209, p=0.021). Additional analyses of the three WV items revealed that this association was largely driven the item on "promotion prospects" (beta=0.230, p=0.007) implying that the perception of good promotion prospects was associated with higher HCC. The finding of elevated HCC with good promotion prospects may initially seem counter-intuitive, but is supported by research documenting

  6. The assessment of cortisol in human hair: associations with sociodemographic variables and potential confounders.

    PubMed

    Dettenborn, L; Tietze, A; Kirschbaum, C; Stalder, T

    2012-11-01

    To inform the future use of hair cortisol measurement, we have investigated influences of potential confounding variables (natural hair colour, frequency of hair washes, age, sex, oral contraceptive (OC) use and smoking status) on hair cortisol levels. The main study sample comprised 360 participants (172 women) covering a wide range of ages (1-91 years; mean = 25.95). In addition, to more closely examine influences of natural hair colour and young age on hair cortisol levels, two additional samples comprising 69 participants with natural blond or dark brown hair (hair colour sample) as well as 28 young children and 34 adults (young age sample) were recruited. Results revealed a lack of an effect for natural hair colour, OC use, and smoking status on hair cortisol levels (all p's >0.10). No influence of frequency of hair washes was seen for proximal hair segments (p = 0.335) but for the third hair segment indicating lower cortisol content (p = 0.008). We found elevated hair cortisol levels in young children and older adults (p < 0.001). Finally, men showed higher hair cortisol levels than women (p = 0.002). The present data indicate that hair cortisol measurement provides a useful tool in stress-related psychobiological research when applied with the consideration of possible confounders including age and sex. PMID:22356099

  7. Hair transplantation update.

    PubMed

    Rogers, Nicole E

    2015-06-01

    Contemporary hair transplant surgery offers results that are natural and undetectable. It is an excellent treatment option for male and female pattern hair loss. Patients are encouraged to also use medical therapy to help protect their surgical results and prevent ongoing thinning of the surrounding hairs. The two major techniques of donor elliptical harvesting and follicular unit extraction are discussed here. PMID:26176286

  8. Effects of chronic, low concentrations of dietary methylmercury on the behavior of juvenile great egrets

    SciTech Connect

    Bouton, S.N.; Frederick, P.C.; Spalding, M.G.; McGill, H.

    1999-09-01

    The authors measured the behavioral effects of methylmercury on 16 great egret chicks (Ardea albus) in a captive dosing experiment. Birds were randomly divided into a control group and groups that received 0.5 or 5 mg methylmercury chloride per kilogram of food at between 12 and 105 d of age. They recorded activity levels, maintenance behavior, and foraging efficiency and determined that mercury affected activity and maintenance behavior. Birds dosed with 5 mg/kg became severely ataxic and were euthanized by 12 weeks of age. The authors found that, during the postfledging period, there were no differences between low-dose and placebo birds in time required to capture live fish in pools or in efficiency of capture. They did find that low-dose birds were less likely to hunt fish. Their results suggest that, at the 0.5 mg/kg concentration in food, there are significant effects of methylmercury on activity, tendency to seek shade, and motivation to hunt prey.

  9. DEVELOPMENTAL NEUROTOXICITY: EVALUATION OF TESTING PROCEDURES WITH METHYLAZOXYMETHANOL AND METHYLMERCURY

    EPA Science Inventory

    Testing procedures that allow for early, rapid and cost-effective investigation of potential developmental neurotoxicants were evaluated using two prototypical developmental neurotoxicants, methylazoxymethanol (MAM) and methylmercury (MeHg). valuation of offspring of Long-Evans r...

  10. Intraindividual stability of hair cortisol concentrations.

    PubMed

    Stalder, Tobias; Steudte, Susann; Miller, Robert; Skoluda, Nadine; Dettenborn, Lucia; Kirschbaum, Clemens

    2012-05-01

    The analysis of cortisol in human hair constitutes a promising method for the retrospective assessment of cumulative cortisol secretion over extended periods of time. An implicit assumption underlying the use of this method is that in the absence of major life changes hair cortisol concentrations show a high level of intraindividual stability, i.e. single hair cortisol assessments exhibit considerable trait-specificity and are only to a smaller extent influenced by state-dependent factors. Here, we present data from two independent studies examining patterns of intraindividual stability in hair cortisol levels. In study I, 45 participants were examined at two sampling points carried out one year apart from each other. In study II, 64 individuals provided data at three sampling points which occurred at two-month intervals. In both studies, at each time point hair was sampled and relevant psychosocial and hair-related variables were assessed. Results of both studies consistently revealed strong test-retest associations for repeated hair cortisol measurements ('r's between 0.68 and 0.79, 'p's <0.0001). Findings of structural equation modelling applied to data of study II showed that single hair cortisol assessments comprise a strong trait component, explaining between 59 and 82% of variance, and are only to a lesser extent influenced by state-related factors. Only inconsistent evidence for covariation of changes in hair cortisol concentrations and simultaneous changes in perceived stress or other relevant variables was seen across the two studies. The current findings suggest a considerable degree of intraindividual stability in hair cortisol levels which highlights the utility of this method for obtaining trait estimates of long-term cortisol secretion in psychoneuroendocrinological research. PMID:21917384

  11. Adverse Effects of Methylmercury: Environmental Health Research Implications

    PubMed Central

    Grandjean, Philippe; Satoh, Hiroshi; Murata, Katsuyuki; Eto, Komyo

    2010-01-01

    Background The scientific discoveries of health risks resulting from methylmercury exposure began in 1865 describing ataxia, dysarthria, constriction of visual fields, impaired hearing, and sensory disturbance as symptoms of fatal methylmercury poisoning. Objective Our aim was to examine how knowledge and consensus on methylmercury toxicity have developed in order to identify problems of wider concern in research. Data sources and extraction We tracked key publications that reflected new insights into human methylmercury toxicity. From this evidence, we identified possible caveats of potential significance for environmental health research in general. Synthesis At first, methylmercury research was impaired by inappropriate attention to narrow case definitions and uncertain chemical speciation. It also ignored the link between ecotoxicity and human toxicity. As a result, serious delays affected the recognition of methylmercury as a cause of serious human poisonings in Minamata, Japan. Developmental neurotoxicity was first reported in 1952, but despite accumulating evidence, the vulnerability of the developing nervous system was not taken into account in risk assessment internationally until approximately 50 years later. Imprecision in exposure assessment and other forms of uncertainty tended to cause an underestimation of methylmercury toxicity and repeatedly led to calls for more research rather than prevention. Conclusions Coupled with legal and political rigidity that demanded convincing documentation before considering prevention and compensation, types of uncertainty that are common in environmental research delayed the scientific consensus and were used as an excuse for deferring corrective action. Symptoms of methylmercury toxicity, such as tunnel vision, forgetfulness, and lack of coordination, also seemed to affect environmental health research and its interpretation. PMID:20529764

  12. RETROSPECTIVE STUDY OF METHYLMERCURY AND OTHER METAL(LOID)S IN MADAGASCAR UNPOLISHED RICE (Oryza sativa L.)

    PubMed Central

    Rothenberg, Sarah E.; Mgutshini, Noma L.; Bizimis, Michael; Johnson-Beebout, Sarah E.; Ramanantsoanirina, Alain

    2014-01-01

    The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n=51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p<0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n=20) and brown bran (n=31) (Wilcoxon rank sum, p=0.06–0.91). Compared to all elements in rice, rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson's r=0.33, p<0.05) and total mercury (r=0.44, p<0.05), while strontium (i.e., tracer for xylem transport) was least correlated with total mercury and methylmercury (r<0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem. PMID:25463705

  13. Determining mercury levels in anchovy and in individuals with different fish consumption habits, together with their neurological effects.

    PubMed

    Çamur, Derya; Güler, Çağatay; Vaizoğlu, Songül Acar; Özdilek, Betül

    2016-07-01

    An increase in enviromental pollution may lead to mercury toxicity of fish origin due to the accumulative nature of methylmercury in fish. The main sources of human exposure to organic mercury compounds are contaminated fish and other seafoods. This descriptive study was planned to determine mercury levels in anchovy and in hair samples from individuals with different fish consumption habits, and to evaluate those individuals in terms of toxic effects. For that purpose, we analyzed 100 anchovies from the Black Sea and 100 anchovies from the Sea of Marmara, and assessed 25 wholesale workers in fish markets and 25 cleaning firm employees from both Ankara and Istanbul. Mercury levels in samples were measured using a cold vapor atomic absorption spectrophotometer. Participants were examined neurologically and mini mental state examination was applied to evaluate their cognitive functions. Mercury levels in fish were found to be below the national and international permitted levels. There was no statistically significant relation between mercury levels and the sea from which fish were caught. Hair mercury levels for all participants were within permitted ranges. However, hair mercury levels in both cities increased significantly with amount and frequency of fish consumption. A significant correlation was determined at correlation analysis between levels of fish consumption and hair mercury levels in the fishmongers and in the entire group (r = 0.32, p = 0.025; r = 0.23, p = 0.023, respectively). Neurological examination results were normal, except for a decrease in deep tendon reflexes in some participants in both cities. There was no correlation between Standardized Mini Mental State Examination results and hair mercury levels. We conclude that establishing a monitoring system for mercury levels in fish and humans will be useful in terms of evaluating potential neurotoxic effects. PMID:27353298

  14. Methylmercury Bioaccumulation in Rice and Wetland Biota: employing integrated indices of processes that drive methylmercury risk

    NASA Astrophysics Data System (ADS)

    Eagles-Smith, C.; Ackerman, J.; Windham-Myers, L.; Fleck, J.

    2013-12-01

    Wetlands often are associated with elevated methylmercury (MeHg) production and food web bioaccumulation, making them potentially important sources of Hg to surrounding waters and to wetland-dependent fish and wildlife. However, the cycling of MeHg through wetlands can vary markedly with wetland type. Agricultural wetlands such as rice fields can exhibit particularly pronounced MeHg concentrations and bioaccumulation because their biogeochemical, hydrological, and ecological characteristics facilitate the conversion of inorganic mercury (Hg) to MeHg. Rice fields are characterized by a series of seasonal extreme wetting and drying cycles, sulfate-containing fertilizers, and high levels of labile organic carbon, all of which are key processes in the Hg cycle. Rice fields comprise approximately 20% of freshwater habitats and 11% of cultivated land area globally, providing critical wildlife habitat while offering substantial economic, human health, and ecosystem benefits. Thus, there is strong impetus to better understand the drivers of Hg cycling in rice fields and to develop useful management approaches for minimizing Hg risk associated with rice agriculture without compromising rice production. We examined the role of rice wetlands on MeHg bioaccumulation through foodwebs by employing biosentinel caged fish as integrators of MeHg cycling processes. With experimental field studies in California's Central Valley, we placed biosentinel fishes into nine rice wetlands that were subjected to three different harvest strategies, and into nine managed wetlands that encompassed three different hydrological regimes. We simultaneously measured a suite of biogeochemical processes in surface water, sediment, and pore water in order to link the response in fish Hg bioaccumulation with within-field processes that regulate MeHg cycling. Our preliminary results indicate that fish Hg concentrations were 1.6 times higher in rice wetlands than in managed wetlands. Additionally, fish Hg

  15. Hair loss in children.

    PubMed

    Alves, Rubina; Grimalt, Ramon

    2015-01-01

    Hair diseases represent frequent complaints in dermatology clinics, and they can be caused by a number of conditions reflected by specific diagnoses. Hair loss is not uncommon in the pediatric group, but its patterns in this group are different from those seen in adults. Additionally, in children, these disorders can have psychological effects that can interfere with growth and development. Hair is easily accessible for examination, and dermatologists are in the enviable situation of being able to study many disorders using simple diagnostic techniques. To fully understand hair loss during childhood, a basic comprehension of normal hair growth is necessary. Knowledge of the normal range and variation observed in the hair of children further enhances its assessment. This chapter has been written in an attempt to facilitate the diagnostic process during daily practice by helping to distinguish between acquired and congenital hair diseases. It can sometimes be difficult to differentiate between abnormality and normality in neonatal hair aspects. Management of hair disorders can be quite a daunting task for the attending physician and mandates a holistic approach to the patient. Some hair disturbances have no effective treatment, and for others, no single treatment is 100% successful. If no effective treatment for a hair loss disease exists, a cosmetic approach is important. PMID:26370644

  16. [Hormones and hair growth].

    PubMed

    Trüeb, R M

    2010-06-01

    With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair. PMID:20502852

  17. Comparison of mercury accumulation among the brain, liver, kidney, and the brain regions of rats administered methylmercury in various phases of postnatal development

    SciTech Connect

    Sakamoto, M.; Nakano, A.

    1995-10-01

    Several animal studies have indicated that a developing organism in its prenatal and early postnatal stage may be at higher risk in toxic metal exposure than in adult stage. Many infants were congenitally affected by methylmercury in the epidemics in Japan and Iraq. The infants reported from Minamata, Japan, had severe cerebral palsy, whereas their mothers had mild or no manifestations of poisoning. Some of the high susceptibility in infants may resulted from the specific features of the methylmercury metabolism in the developing organisms. Prenatal or postnatal development is characterized by functional immaturity of organs, which may affect the mercury (Hg) accumulation among organs. It seems possible that the Hg distribution might, in fact, reflect the toxic effects of methylmercury during a given developing phase. Thus, its distribution deserves closer examination. In our previous study, when a toxic level of methylmercury was administered, the Hg distribution and its effects on body weight gain and neurological disorders were found to be different among the rat postnatal developing phases. In the present study the Hg distribution among organs and brain regions was investigated during the several development phases with a nontoxic level of methylmercury treatment. 24 refs., 1 fig., 2 tabs.

  18. Mental retardation and prenatal methylmercury toxicity

    SciTech Connect

    Trasande, L.; Schechter, C.B.; Haynes, K.A.; Landrigan, P.J.

    2006-03-15

    Methylmercury (MeHg) is a developmental neurotoxicant; exposure results principally from consumption of seafood contaminated by mercury (Hg). In this analysis, the burden of mental retardation (MR) associated with methylmercury exposure in the 2000 U.S. birth cohort is estimated, and the portion of this burden attributable to mercury (Hg) emissions from coal-fired power plants is identified. The aggregate loss in cognition associated with MeHg exposure in the 2000 U.S. birth cohort was estimated using two previously published dose-response models that relate increases in cord blood Hg concentrations with decrements in IQ. MeHg exposure was assumed not to be correlated with native cognitive ability. Previously published estimates were used to estimate economic costs of MR caused by MeHg. Downward shifts in IQ resulting from prenatal exposure to MeHg of anthropogenic origin are associated with 1,566 excess cases of MR annually (range: 376-14,293). This represents 3.2% of MR cases in the US (range: 0.8%-29.2%). The MR costs associated with decreases in IQ in these children amount to $2.0 billion/year (range: $0.5-17.9 billion). Hg from American power plants accounts for 231 of the excess MR cases year (range: 28-2,109), or 0.5% (range: 0.06%-4.3%) of all MR. These cases cost $289 million (range: $35 million-2.6 billion). Toxic injury to the fetal brain caused by Hg emitted from coal-fired power plants exacts a significant human and economic toll on American children.

  19. Cochlea hair cell rescue after a noise-induced hearing loss using a low level laser therapy (LLLT)

    NASA Astrophysics Data System (ADS)

    Rhee, Chung-Ku; Bahk, Chan Woong; Jung, Jae Yun; Ahn, Jin-Chul; Suh, Myung-Whan

    2011-03-01

    Aim: To see the effect of LLLT on noise-induced hearing loss. Methods: Eleven rats were exposed to noise (120 dB, 16 kHz, 6 h) and left ears were irradiated at 60J/cm2, 830 nm laser for 12 days. Right ears were control. Hearing levels were measured at frequencies of 4, 8, 12, 16, 32 kHz before noise exposure and after 12th irradiations. Results: The initial hearing levels were 26.5+/-4.7, 24.5+/-5.0, 24.0+/-5.2, 24.0+/-3.2, 24.5+/-5.5 dB SPL. After noise exposure, thresholds were 63.5+/-15.1, 64+/-16.8, 71.5+/-11.3, 73.5+/-15.6, 67.5+/-14.4 dB SPL in 4, 8, 12, 16, 32 kHz. After 12th irradiation, thresholds of treated ears recovered significantly 21+/-4.2, 20+/-3.5, 24+/-11.9, 24+/-12.9, 21+/-2.2 dB SPL and that of the untreated right ears measured 36.3+/-22.9, 45+/-15.8, 66.3+/-22.9, 50+/-16.8, 43.8+/-21.4 dB SPL. Conclusion: LLLT may promote recovery of hearing after noiseinduced hearing loss.

  20. A Physiologically-based Model for Methylmercury Uptake and Accumulation in Female American Kestrels

    EPA Science Inventory

    A physiologically-based model was developed to describe the uptake, distribution, and elimination of methylmercury in female American Kestrels (Falco sparverius). The model was adapted from established models for methylmercury in rodents. Features unique to the model include meth...

  1. Biochar amendment reduced methylmercury accumulation in rice plants.

    PubMed

    Shu, Rui; Wang, Yongjie; Zhong, Huan

    2016-08-01

    There is growing concern about methylmercury (MeHg) accumulation in rice grains and thus enhanced dietary exposure to MeHg in Asian countries. Here, we explored the possibility of reducing grain MeHg levels by biochar amendment, and the underlying mechanisms. Pot (i.e., rice cultivation in biochar amended soils) and batch experiments (i.e., incubation of amended soils under laboratory conditions) were carried out, to investigate MeHg dynamics (i.e., MeHg production, partitioning and phytoavailability in paddy soils, and MeHg uptake by rice) under biochar amendment (1-4% of soil mass). We demonstrate for the first time that biochar amendment could evidently reduce grain MeHg levels (49-92%). The declines could be attributed to the combined effects of: (1) increased soil MeHg concentrations, probably explained by the release of sulfate from biochar and thus enhanced microbial production of MeHg (e.g., by sulfate-reducing bacteria), (2) MeHg immobilization in soils, facilitated by the large surface areas and high organosulfur content of biochar, and (3) biodilution of MeHg in rice grains, due to the increased grain biomass under biochar amendment (35-79%). These observations together with mechanistic explanations improve understanding of MeHg dynamics in soil-rice systems, and support the possibility of reducing MeHg phytoaccumulation under biochar amendment. PMID:27045620

  2. Hoxc13 is a crucial regulator of murine hair cycle.

    PubMed

    Qiu, Weiming; Lei, Mingxing; Tang, Hui; Yan, Hongtao; Wen, Xuhong; Zhang, Wei; Tan, Ranjing; Wang, Duan; Wu, Jinjin

    2016-04-01

    Hair follicles undergo cyclical growth and regression during postnatal life. Hair regression is an apoptosis-driven process strictly controlled by micro- and macro-environmental signals. However, how these signals are controlled remains largely unknown. Hoxc13, a member of the Hox gene family, is reported to play an important role in hair follicle differentiation. In the present study, we observed that Hoxc13 was highly expressed in the outer root sheath, matrix, medulla and inner root sheath of hair follicles in a hair cycle-dependent manner. We therefore investigated the role of Hoxc13 in hair follicle cycling. Injection of ShRNA (ShHoxc13) to suppress Hoxc13 in early anagen promoted premature catagen entry, shown by significantly decreased hair length and hair bulb size, increased percentage of catagen hair follicles, hair cycle score and TUNEL+ cells and inhibited proliferation. In contrast, local injection of recombinant Hoxc13 polypeptide (rhHoxc13) during the late anagen phase prolonged the anagen phase. Additionally, rhHoxc13 injections during the telogen phase significantly promoted hair growth and induced the anagen progression. At the molecular level, the expression of phosphorylated smad2 (p-smad2), a key factor of active TGF-β1 signaling, was up-regulated in the ShHoxc13-treated hair follicles and down-regulated in rhHoxc13-treated hair follicles, suggesting that Hoxc13 might block anagen-catagen transition by inhibiting the TGF-β1 signaling. Taken together, our data strongly suggest that Hoxc13 is a novel and crucial regulator of the hair cycle. This might also provide an understanding of the mechanism of the 'hair cycle clock' and the development of alopecia treatments. PMID:26553656

  3. Drugs and hair loss.

    PubMed

    Patel, Mansi; Harrison, Shannon; Sinclair, Rodney

    2013-01-01

    Hair loss is a common complaint, both in men and women, and use of prescription medications is widespread. When there is a temporal association between the onset of hair loss and commencement of a medication, the medication is commonly thought to have caused the hair loss. However, hair loss and in particular telogen effluvium may occur in response to a number of triggers including fever, hemorrhage, severe illness, stress, and childbirth, and a thorough exclusion of these potential confounders is necessary before the hair loss can be blamed on the medication. Certain medications are known to cause hair loss by a variety of mechanisms including anagen arrest, telogen effluvium, or accentuation of androgenetic alopecia by androgens. PMID:23159177

  4. Ethnic hair disorders.

    PubMed

    Lindsey, Scott F; Tosti, Antonella

    2015-01-01

    The management of hair and scalp conditions is difficult in any patient, especially given the emotional and psychological implications of hair loss. This undertaking becomes even more challenging in the ethnic patient. Differences in hair care practices, hair shaft morphology, and follicular architecture add complexity to the task. It is imperative that the physician be knowledgeable about these practices and the phenotypic differences seen in ethnic hair in order to appropriately diagnose and treat these patients. In this chapter, we will discuss cultural practices and morphologic differences and explain how these relate to the specific disorders seen in ethnic populations. We will also review the most prominent of the ethnic hair conditions including acquired trichorrhexis nodosa, traction alopecia, central centrifugal cicatricial alopecia, pseudofolliculitis barbae, dissecting cellulitis, and acne keloidalis nuchae. PMID:26370652

  5. Female pattern hair loss.

    PubMed

    Ioannides, Dimitrios; Lazaridou, Elizabeth

    2015-01-01

    Female pattern hair loss, or female pattern androgenetic alopecia, is a nonscarring alopecia with a multi-factorial etiology that mostly affects postmenopausal women and is characterized by a reduction in hair density over the crown and frontal scalp. The clinical picture is characterized by a diffuse rarefaction of scalp hair over the mid-frontal scalp and a more-or-less intact frontal hairline without any signs of inflammation or scarring. Although the disease poses only a cosmetic concern, it is chronic and may have a significant negative psychological impact on the affected person. The aim of treating female pattern hair loss is to reduce hair loss and, to a certain extent, succeed in promoting hair regrowth. Various treatment methods are available, but it remains unclear which are the most effective. Early initiation of treatment and the combination of various modalities seem to be more efficacious than monotherapy. PMID:26370643

  6. Effects of solar radiation on hair and photoprotection.

    PubMed

    Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

    2015-12-01

    In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. PMID:26454659

  7. Advances and challenges in hair restoration of curly Afrocentric hair.

    PubMed

    Rogers, Nicole E; Callender, Valerie D

    2014-04-01

    Although the biochemical composition of hair is similar among racial and ethnic groups, the hair structure between them varies, and individuals with curly hair pose specific challenges and special considerations when a surgical option for alopecia is considered. Hair restoration in this population should therefore be approached with knowledge on the clinical characteristics of curly hair, hair grooming techniques that may influence the management, unique indications for the procedure, surgical instrumentation used, and the complications that may arise. PMID:24680003

  8. Hair implant complications.

    PubMed

    Hanke, C W; Norins, A L; Pantzer, J G; Bennett, J E

    1981-04-01

    Four men who underwent hair implantation for pattern baldness were treated for complications such as infection, foreign-body reaction, pruritus, and scarring. The complications were similar to those reported with synthetic modacrylic fiber implants that have been used for the same purpose. Although we believe this is the first article to report complications from hair implants, the illogical basis of the procedure suggests that complications will occur in many unsuspecting patients who undergo hair implantation. PMID:7009899

  9. Tarantula hair keratitis.

    PubMed

    Mangat, Simran Singh; Newman, Bill

    2012-10-26

    We describe a 12-year-old boy in England with keratitis secondary to tarantula hairs embedded within the stroma of his cornea. Every attempt must be made to isolate these hairs at the first visit as they have a barbed nature and have a propensity to propagate through ocular tissues. A chronic keratitis requiring long-term steroid use may result if hairs persist in the cornea. Children who keep tarantulas as pets should be instructed on safe handling to prevent the tarantula from adopting defence mechanisms and shedding their hairs. PMID:23242405

  10. Female hair restoration.

    PubMed

    Unger, Robin H

    2013-08-01

    Female hair loss is a devastating issue for women that has only relatively recently been publicly acknowledged as a significant problem. Hair transplant surgery is extremely successful in correcting the most cosmetically problematic areas of alopecia. This article discusses the surgical technique of hair transplantation in women in detail, including pearls to reduce postoperative sequelae and planning strategies to ensure a high degree of patient satisfaction. A brief overview of some of the medical treatments found to be helpful in slowing or reversing female pattern hair loss is included, addressing the available hormonal and topical treatments. PMID:24017982

  11. Laser hair removal pearls.

    PubMed

    Tierney, Emily P; Goldberg, David J

    2008-03-01

    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the follicle through the targeting of melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Pearls of laser hair removal are presented in this review, focusing on four areas of recent development: 1 treatment of blond, white and gray hair; 2 paradoxical hypertrichosis; 3 laser hair removal in children; and 4 comparison of lasers and IPL. Laser and light-based technologies to remove hair represents one of the most exciting areas where discoveries by dermatologists have led to novel treatment approaches. It is likely that in the next decade, continued advancements in this field will bring us closer to the development of a more permanent and painless form of hair removal. PMID:18330794

  12. Hair tourniquet syndrome: revisited

    PubMed Central

    HUSSIN, P.; MAWARDI, M.; MASRAN, M.S.; GANAISAN, P.

    2015-01-01

    Hair tourniquet syndrome is a rare condition. It is an important emergency condition where urgent attention is needed. In this condition, body appendages are strangulated by hair that acts like a tourniquet. A strand or strands of hair act like a circumferential constriction band and subsequently strangulate the body appendages. Commonly affected sites include fingers, toes or even genitals. Failure to identify and release the acute constriction may result in amputation of affected body part. We report two cases of hair tourniquet syndrome of the thumb and toe that were successfully released without complications. PMID:26712259

  13. Hair Loss in New Moms

    MedlinePlus

    ... Video library Find a dermatologist Hair loss in new moms Many new moms see noticeable hair loss ... regain normal fullness even earlier. Dermatologists’ tips for new mothers If the excessive hair shedding bothers you, ...

  14. Coping with cancer - hair loss

    MedlinePlus

    Alopecia ... after fast-growing cells. While chemo can cause hair loss all over your body, radiation only affects the ... Hair loss usually happens 1 to 3 weeks after the first chemo or radiation treatment. The hair on ...

  15. Coping with cancer -- hair loss

    MedlinePlus

    ... gov/ency/patientinstructions/000914.htm Coping with cancer - hair loss To use the sharing features on this ... lose your hair. Why Cancer Treatments can Cause Hair Loss Many chemotherapy drugs attack fast-growing cells. ...

  16. Why Does Hair Turn Gray?

    MedlinePlus

    ... Each hair follicle contains a certain number of pigment cells. These pigment cells continuously produce a chemical called melanin (say: ... each hair contains. As we get older, the pigment cells in our hair follicles gradually die. When ...

  17. Methylmercury formation in a wetland mesocosm amended with sulfate.

    PubMed

    Harmon, S M; King, J K; Gladden, J B; Chandler, G T; Newman, L A

    2004-01-15

    This study used an experimental model to evaluate methylmercury accumulation when the soil of a constructed wetland is amended with sulfate. The model was planted with Schoenoplectus californicus and designed to reduce wastestream metals and metal-related toxicity. The soil was varied during construction to provide a control and two sulfate treatments which were equally efficient at overall mercury and copper removal. After an initial stabilization period, methylmercury concentrations in porewater were up to three times higher in the sulfate-treated porewater (0.5-1.6 ng/L) than in the control (<0.02-0.5 ng/L). Mean percent methylmercury was 9.0% in the control with 18.5 and 16.6% in the low- and high-sulfate treatments, respectively. Methylmercury concentrations measured in mesocosm surface water did not reflect the differences between the control and the sulfate treatments that were noted in porewater. The mean bulk sediment methylmercury concentration in the top 6 cm of the low-sulfate treatment (2.33 ng/g) was significantly higher than other treatment means which ranged from 0.96 to 1.57 ng/g. Total mercury in sediment ranged from 20.8 to 33.4 ng/g, with no differences between treatments. Results suggest that the non-sulfate-amended control was equally effective in removing metals while keeping mercury methylation low. PMID:14750744

  18. An overview of unwanted female hair.

    PubMed

    Blume-Peytavi, U

    2011-12-01

    Unwanted facial hair (UFH) is an important but often overlooked issue, with over 40% of women experiencing some degree of UFH. In the female population a wide spectrum of unwanted hair concerns is represented - from biologically normal but undesirable to excessive unwanted hair with an underlying pathology. While women may seek to manage unwanted hair across their bodies, UFH is a particular concern, due to its negative impact on perceived femininity. There may not always be a direct correlation between degree of severity diagnosed objectively by the physician and level of concern and impact upon the patient. This review discusses the spectrum of facial hair experience and outlines the clinical approach to unwanted hair management including UFH. It highlights the importance of a treatment regimen which should respond to the causation factors and needs of the individual. This will lead to a holistic treatment approach including evaluation of the implementation of emotional coping strategies and on-going support, lifestyle modifications, pharmacological interventions (to address underlying pathologies) and the use of cosmetic hair removal methods as either a stand-alone or adjunct treatment as appropriate to the individual. PMID:22171681

  19. Elevated hair cortisol concentrations in endurance athletes.

    PubMed

    Skoluda, Nadine; Dettenborn, Lucia; Stalder, Tobias; Kirschbaum, Clemens

    2012-05-01

    Engaging in intensive aerobic exercise, specifically endurance sports, is associated with HPA axis activation indicated by elevated cortisol levels. Whether the repeated short-term elevations in cortisol levels result in higher long-term cortisol exposure of endurance athletes has been difficult to examine since traditional methods of cortisol assessments (saliva, blood, urine) reflect only relatively short time periods. Hair segment analysis provides a new method to assess cumulative cortisol secretion over prolonged time periods in a retrospective fashion. The aim of this study was to investigate cumulative cortisol secretion over several months reflecting intensive training and competitive races by examining hair cortisol levels of endurance athletes. Hair samples were obtained from 304 amateur endurance athletes (long-distance runners, triathletes, cyclists) and 70 controls. Cortisol concentrations were determined in the first to third 3-cm hair segments most proximal to the scalp. In addition, self-report measures of training volume were obtained. Endurance athletes exhibited higher cortisol levels in all three hair segments compared to controls (p<.001). Positive correlations between the cortisol concentration in the first hair segment and each indicator of training volume were found (all p<.01). These data suggest that repeated physical stress of intensive training and competitive races among endurance athletes is associated with elevated cortisol exposure over prolonged periods of time. These findings may have important implications with regard to somatic and mental health of athletes which should be investigated in future research. PMID:21944954

  20. Characterization of the effects of methylmercury on Caenorhabditis elegans

    SciTech Connect

    Helmcke, Kirsten J.; Syversen, Tore; Miller, David M.; Aschner, Michael

    2009-10-15

    The rising prevalence of methylmercury (MeHg) in seafood and in the global environment provides an impetus for delineating the mechanism of the toxicity of MeHg. Deleterious effects of MeHg have been widely observed in humans and in other mammals, the most striking of which occur in the nervous system. Here we test the model organism, Caenorhabditis elegans (C. elegans), for MeHg toxicity. The simple, well-defined anatomy of the C. elegans nervous system and its ready visualization with green fluorescent protein (GFP) markers facilitated our study of the effects of methylmercuric chloride (MeHgCl) on neural development. Although MeHgCl was lethal to C. elegans, induced a developmental delay, and decreased pharyngeal pumping, other traits including lifespan, brood size, swimming rate, and nervous system morphology were not obviously perturbed in animals that survived MeHgCl exposure. Despite the limited effects of MeHgCl on C. elegans development and behavior, intracellular mercury (Hg) concentrations ({<=} 3 ng Hg/mg protein) in MeHgCl-treated nematodes approached levels that are highly toxic to mammals. If MeHgCl reaches these concentrations throughout the animal, this finding indicates that C. elegans cells, particularly neurons, may be less sensitive to MeHgCl toxicity than mammalian cells. We propose, therefore, that C. elegans should be a useful model for discovering intrinsic mechanisms that confer resistance to MeHgCl exposure.

  1. Methylmercury biomagnification in an Arctic pelagic food web.

    PubMed

    Ruus, Anders; Øverjordet, Ida B; Braaten, Hans Fredrik V; Evenset, Anita; Christensen, Guttorm; Heimstad, Eldbjørg S; Gabrielsen, Geir W; Borgå, Katrine

    2015-11-01

    Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, and emitted gaseous Hg enters the Arctic from lower latitudes by long-range transport. In aquatic systems, anoxic conditions favor the bacterial transformation of inorganic Hg to methylmercury (MeHg), which has a greater potential for bioaccumulation than inorganic Hg and is the most toxic form of Hg. The main objective of the present study was to quantify the biomagnification of MeHg in a marine pelagic food web, comprising species of zooplankton, fish, and seabirds, from the Kongsfjorden system (Svalbard, Norway), by use of trophic magnification factors. As expected, tissue concentrations of MeHg increased with increasing trophic level in the food web, though at greater rates than observed in several earlier studies, especially at lower latitudes. There was strong correlation between MeHg and total Hg concentrations through the food web as a whole. The concentration of MeHg in kittiwake decreased from May to October, contributing to seasonal differences in trophic magnification factors. The ecology and physiology of the species comprising the food web in question may have a large influence on the magnitude of the biomagnification. A significant linear relationship was also observed between concentrations of selenium and total Hg in birds but not in zooplankton, suggesting the importance of selenium in Hg detoxification for individuals with high Hg concentrations. PMID:26274519

  2. Characterization of the effects of methylmercury on Caenorhabditis elegans

    PubMed Central

    Helmcke, Kirsten J.; Syversen, Tore; Miller, David M.; Aschner, Michael

    2009-01-01

    The rising prevalence of methylmercury (MeHg) in seafood and in the global environment provides an impetus for delineating the mechanism of the toxicity of MeHg. Deleterious effects of MeHg have been widely observed in humans and in other mammals, the most striking of which occur in the nervous system. Here we test the model organism, Caenorhabditis elegans (C. elegans), for MeHg toxicity. The simple, well-defined anatomy of the C. elegans nervous system and its ready visualization with green fluorescent protein (GFP) markers facilitated our study of the effects of methylmercuric chloride (MeHgCl) on neural development. Although MeHgCl was lethal to C. elegans, induced a developmental delay, and decreased pharyngeal pumping, other traits including lifespan, brood size, swimming rate, and nervous system morphology were not obviously perturbed in animals that survived MeHgCl exposure. Despite the limited effects of MeHgCl on C. elegans development and behavior, intracellular mercury (Hg) concentrations (≤ 3 ng Hg/mg protein) in MeHgCl-treated nematodes approached levels that are highly toxic to mammals. If MeHgCl reaches these concentrations throughout the animal, this finding indicates that C. elegans cells, particularly neurons, may be less sensitive to MeHgCl toxicity than mammalian cells. We propose, therefore, that C. elegans should be a useful model for discovering intrinsic mechanisms that confer resistance to MeHgCl exposure. PMID:19341752

  3. Production and retention of methylmercury in inundated boreal forest soils.

    PubMed

    Rolfhus, Kristofer R; Hurley, James P; Bodaly, Richard A Drew; Perrine, Gregory

    2015-03-17

    The Flooded Uplands Dynamics Experiment (FLUDEX) was an ecosystem-scale study examining the production of methylmercury (MeHg) and greenhouse gases from reservoirs constructed on an upland boreal forest landscape in order to quantify their dependence upon carbon stores. We detail the within-reservoir production and storage of MeHg before, during, and nine years after the experiment. The reservoirs were net MeHg producers during the first two years of flooding, and net demethylating systems afterward. During years 1-3, a rapid pulse of MeHg and total Hg was observed in floodwater, followed by substantial increases in MeHg in seston and sediment. Resampling of the dry reservoirs nine years after the experiment ended indicated that organic soil MeHg was still 8 to 52-fold higher than preflood conditions, and averaged 86% of the levels recorded at the end of the third flooding year. Both total Hg and MeHg retention in soil were a strong function of organic carbon content. The time scale of soil MeHg retention may help explain the decadal time lag frequently observed for the decrease of piscivorous fish Hg concentrations in new reservoirs. Predicted extreme precipitation events associated with climate change may serve to make landscapes more susceptible to this process. PMID:25668143

  4. Idiopathic hirsutism: excessive bodily and facial hair in women.

    PubMed

    Elghblawi, Ebtisam

    Hirsutism is the excessive and increased bodily and facial hair growth in women in locations where hair is normally minimal or absent. It refers to the growth of hair in a pattern normally occurring only in men, and therefore primarily raises psychological, cosmetic and social concerns. Idiopathic hirsutism (IH), where the cause of excessive hair growth is unknown, is considered to be the most common form of hirsutism. It is suspected that this type of hirsutism may be familial, as there is often a family history of the condition. Women with IH will generally have normal menses and normal levels of testosterone. There are many treatment modalities that fall into two broad groups: medical and mechanical treatment. An example of a medical treatment is when an agent is used, which interferes with the synthesis of androgen at the ovarian or adrenal level, or by inhibiting the effect of androgen at the receptor level. An example of a mechanical treatment is laser hair removal, where the hair follicle is destroyed; however, much depends on the on the skill of the treating practitioner, laser type, laser spot size, skin type, hair colour, and the stage at which the hair follicles were during their hair growth cycle, and the delivered wavelength. Laser offers the fastest method of hair loss. Other mechanical treatments include electrolysis, depilatory creams, plucking and waxing. This article presents a general overview of IH, including a definition, diagnostic measures, clinical manifestations, normal and abnormal physiology, and treatment options. PMID:18414261

  5. Occurrence of methylmercury in Lake Valencia, Venezuela

    SciTech Connect

    Jaffe, R.; Cai, Y.; West-Thomas, J.

    1997-12-31

    The presence of mercury in the environment has received renewed attention during recent years. This is in part due to the known human health and ecological effects of the highly toxic organomercury compounds, and to the fact that novel and improved analytical techniques such as atomic fluorescence spectroscopy (AFS) and capillary chromatography with AFS detection, have enhanced significantly the detection of trace amounts of mercury and organo mercurials in environmental samples. Such techniques have allowed for a better understanding of the biogeochemical cycle of mercury in the aquatic environment. This paper reports on the presence of methylmercury in the water column and sediments of a hyper-eutrophic lake. Lake Valencia is a freshwater lake located in North-Central Venezuela`s Aragua Valley. The lake`s surface area covers approximately 350 km{sup 2}, with a mean depth of 19 m and a maximum depth of 41 m. Due to the discharge of waste waters from the cities of Maracay and Valencia, as well as from other smaller villages and agricultural areas in its watershed, Lake Valencia has become hyper-eutrophic. The population of phytoplankton, particularly of blue-green algae, has increased dramatically during the last two decades resulting in anoxic conditions in the lower part of the water column during most of the year. In addition, concentrations of anthropogenic chemicals, including heavy metals, have increased in the Lake during the last four decades. 15 refs., 2 figs.

  6. Associations of Baroreflex Sensitivity, Heart Rate Variability, and Initial Orthostatic Hypotension with Prenatal and Recent Postnatal Methylmercury Exposure in the Seychelles Child Development Study at Age 19 Years

    PubMed Central

    Périard, Daniel; Beqiraj, Bujar; Hayoz, Daniel; Viswanathan, Bharathi; Evans, Katie; Thurston, Sally W.; Davidson, Philip W.; Myers, Gary J.; Bovet, Pascal

    2015-01-01

    Background: A few studies have suggested an association between prenatal exposure to methylmercury and decreased heart rate variability (HRV) related to autonomic heart function, but no study has examined this association using baroreflex sensitivity (BRS). In this study we assessed the distribution of BRS and immediate orthostatic hypotension (IOH) in young Seychellois adults and their associations with exposure to prenatal and recent postnatal methylmercury. Methods: Subjects in theSeychelles Child Development Study (SCDS) main cohort were evaluated at age 19 years. Non-invasive beat-to-beat blood pressure (BP) monitoring (Finapres, Ohmeda) was performed at rest and during active standing in 95 consecutive subjects. Recent postnatal mercury exposure was measured in subjects’ hair at the age of 19 years and prenatal exposure in maternal hair grown during pregnancy. BRS was estimated by sequence analysis to identify spontaneous ascending and descending BP ramps. HRV was estimated by the following markers: PNN50 (relative numbers of normal-to-normal intervals which are shorter by more than 50 ms than the immediately following normal-to-normal intervals); rMSSD (root mean of the squared sum of successive interval differences); LF/HF (low frequency/high frequency component ratio); ratio of the mean expiratory/inspiratory RR intervals (EI ratio); and the ratio between the longest RR interval 30 s after active standing and the shortest RR interval at 15 s (Max30/Min15). IOH was estimated by the deepest BP fall within the first 15 s after active standing up. Results: Prenatal MeHg exposures were similar in boys and girls (6.7 ± 4.3, 6.7 ± 3.8 ng/g) but recent postnatal mercury levels were higher in males than females (11.2 ± 5.8 vs 7.9 ± 4.3 ng/g, p = 0.003). Markers of autonomic heart rate control were within the normal range (BRS: 24.8 ± 7 ms/mm Hg, PNN50: 24.9 ± 6.8%, rMSSD: 68 ± 22, LF/HF: 0.61 ± 0.28) in both sexes. After standing, 51.4% of subjects had a

  7. Ecological risk of methylmercury in Everglades National Park, Florida, USA.

    PubMed

    Rumbold, D G; Lange, T R; Axelrad, D M; Atkeson, T D

    2008-10-01

    Dramatic declines in mercury levels have been reported in Everglades biota in recent years. Yet, methylmercury (MeHg) hot spots remain. This paper summarizes a risk assessment of MeHg exposure to three piscivorous wildlife species (bald eagle, Haliaeetus leucocephalus; wood stork, Mycteria americana; and great egret, Ardea albus) foraging at a MeHg hot spot in northern Everglades National Park (ENP). Available data consisted of literature-derived life history parameters and tissue concentrations measured in 60 largemouth bass (Micropterus salmoides), 60 sunfish (Lepomis spp.), and three composite samples of mosquitofish (Gambusia holbrooki) collected from 2003 to 2005. To assess risk, daily MeHg intake was estimated using Monte Carlo methods and compared to literature-derived effects thresholds. The results indicated the likelihood was very high, ranging from 98-100% probability, that these birds would experience exposures above the acceptable dose when foraging in northern ENP. Moreover, the likelihood that these birds would experience exposures above the lowest-observed-adverse-effect level (LOAEL) ranged from a 14% probability for the wood stork to 56% probability for the eagle. Data from this study, along with the results from several other surveys suggest that biota in ENP currently contain the highest MeHg levels in South Florida and that these levels are similar to or greater than other known MeHg hot spots in the United States. Given these findings, this paper also outlines a strategic plan to obtain additional measured and modeled information to support risk-based management decisions in ENP. PMID:18679795

  8. Help! It's Hair Loss!

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Help! It's Hair Loss! KidsHealth > For Kids > Help! It's Hair Loss! Print A A A Text Size ... part above the skin, is dead. (That's why it doesn't hurt to get a haircut!) This ...

  9. Hair Casts or Pseudonits

    PubMed Central

    França, Katlein; Villa, Ricardo Tadeu; Silva, Isabella Rezende; de Carvalho, Cristine Almeida; Bedin, Valcinir

    2011-01-01

    Hair casts or pseudonits are thin, elongated, cylindrical concretions that encircle the hair shaft and can be easily dislodged. A case of pseudonits in a 9-year-old girl is reported. Though not unusual, false diagnoses are common. PMID:22223977

  10. Laser hair removal.

    PubMed

    Wanner, Molly

    2005-01-01

    Since 1996, there have been numerous advances in hair laser removal that utilize melanin as a chromophore. All of the devices on the market may be used in patients with light skin (phototypes I-III) and yield hair reduction near 75%. The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as well as intense pulsed light are commonly used devices for hair laser removal. The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair removal in dark-skinned patients because of its long wavelength, although the diode laser, alexandrite laser, and intense pulse light may be used. For treatment of light hair, combination radiofrequency and optical devices as well as photodynamic therapy are under investigation. PMID:16229722

  11. Mechanisms of methylmercury transport across the blood-brain barrier

    SciTech Connect

    Kerper, L.E.

    1993-01-01

    Methylmercury readily enters the brain of exposed individuals, and is highly neurotoxic. The goal of this research was to determine the mechanisms of methylmercury transport across both the luminal and abluminal membranes of brain capillary endothelial cells, the cells which comprise the blood-brain barrier. The rapid carotid injection technique was used in rats to investigate the uptake of methylmercury from blood into brain endothelial cells. Uptake of ([sup 203]Hg)-methylmercury complexed with L-cysteine (CH[sub 3] [sup 203]Hg-L-Cys) was more rapid than that of ([sup 203]Hg)-methylmercury complexed with D-cysteine or bovine serum albumin. Uptake of CH[sub 3][sup 203]Hg-L-Cys was saturable, and was inhibited by substrates for the L (alanine-preferring) carrier. Brain uptake of [sup 14]C-L-methionine was inhibited by CH[sub 3]Hg-L-Cys but not by CH[sub 3]HgCl. Uptake of [sup 203]Hg administered as CH[sub 3]Hg-L-Cys-glutathione (CH[sub 3][sup 203]Hg-GSH) was comparable to CH[sub 3][sup 203]Hg-L-Cys uptake at 2 [mu]M. L-Methionine and 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) inhibited [sup 203]Hg uptake administered as CH[sub 3][sup 203]Hg-GSH, whereas acivicin had no effect. This uptake was also inhibited by S-ethylglutathione when pH of the injection solution was allowed to rise to 8.5. In later experiments performed at pH 8.2, uptake of [sup 203]Hg administered as CH[sub 3][sup 203]Hg-GSH was inhibited only by BCH. To study mechanisms of methylmercury efflux from endothelial cells, a primary culture of bovine brain capillary endothelial cells was developed. Intracellular glutathione concentration was 2.6 [+-] 0.7 mM. Incubation of CH[sub 3][sup 203]HgCl-preloaded cells with GSH depletors decreased ([sup 203]Hg)-methylmercury efflux in a dose-dependent manner which correlated with intracellular GSH concentrations. ([sup 203]Hg)-Methylmercury efflux was also inhibited by GSH-S-conjugates an GSH analogs, but not by amino acids.

  12. Comparison of game-farm and wild-strain mallard ducks in accumulation of methylmercury

    USGS Publications Warehouse

    Heinz, G.H.

    1979-01-01

    The accumulation of mercury was compared in game-farm and wild-strain mallard ducks fed a diet containing 0.5 ppm mercury in the form of methylmercury dicyandiamide. There were no significant differences between the two strains in levels of mercury that accumulated in blood, kidney, liver, breast muscle, brain, eggs, or ducklings. Mercury levels in blood were significantly correlated with levels in other tissues and eggs, as were levels in down feathers of ducklings with levels in carcasses of ducklings. The results indicate that game-farm mallards are probably suitable substitutes for wild mallards in toxicological work, that blood samples can be used to estimate levels of mercury in other tissues of adults, and that down feathers are predictive of mercury levels in duckling carcasses.

  13. Toxic Trace Elements in the Hair of Children with Autism

    ERIC Educational Resources Information Center

    Fido, Abdullahi; Al-Saad, Samira

    2005-01-01

    Excess or deficiency of natural trace elements has been implicated in the etiology of autism. This study explores whether concentration levels of toxic metals in the hair of children with autism significantly differ from those of age- and sex-matched healthy controls. In-hair concentration levels of antimony, uranium, arsenic, beryllium, mercury,…

  14. Bacterial methylmercury degradation in Florida Everglades peat sediment

    USGS Publications Warehouse

    Marvin-DiPasquale, M. C.; Oremland, R.S.

    1998-01-01

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently ???0.1 d-1 and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046 ?? 0.023 d-1 (n = 17) for 1-2 day incubations. In-situ degradation rates were estimated to be 0.02-0.5 ng of MeHg (g of dry sediment)-1 d-1, increasing from eutrophied to pristine areas. Nitrate-respiring bacteria did not demethylate MeHg, and NO3- addition partially inhibited degradation in some cases. MeHg degradation rates were not affected by PO43- addition. 14CO2 production in all samples indicated that oxidative demethylation (OD) was an important degradation mechanism. OD occurred over 5 orders of magnitude of applied MeHg concentration, with lowest limits [1-18 ng of MeHg (g of dry sediment)-1] in the range of in-situ MeHg levels. Sulfate reducers and methanogens were the primary agents of anaerobic OD, although it is suggested that methanogens dominate degradation at in-situ MeHg concentrations. Specific pathways of OD by these two microbial groups are proposed.Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently ???0.1 d-1 and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046??0.023 d-1 (n = 17) for 1-2 day incubations. In-situ degradation rates were estimated to be 0

  15. Methylmercury poisoning: long-term clinical, radiological, toxicological, and pathological studies of an affected family.

    PubMed

    Davis, L E; Kornfeld, M; Mooney, H S; Fiedler, K J; Haaland, K Y; Orrison, W W; Cernichiari, E; Clarkson, T W

    1994-06-01

    For 3 months in 1969 a family in the United States that included a pregnant mother consumed pork containing methylmercury. Children, aged 20, 13, and 8 years and a neonate, developed severe neurological signs. Twenty-two years later, the 2 oldest had cortical blindness or constricted visual fields, diminished hand proprioception, choreoathetosis, and attentional deficits. Magnetic resonance images showed tissue loss in the calcarine and parietal cortices and cerebellar folia. The youngest had quadriplegia, blindness, and severe mental retardation until their deaths. The brain of the 8-year-old who died at age 30 showed cortical atrophy, neuronal loss, and gliosis, most pronounced in the paracentral and parietooccipital regions. The total mercury level in formalin-fixed, left occipital cortex was 1,974 ng/gm as measured by atomic absorption. Regional brain mercury levels correlated with extent of brain damage. A control patient had 38.5 ng of mercury/gm in the occipital cortex. Systemic organs in the patient and a control subject had comparable mercury levels. In mercury-intoxicated rats, we found that only 5 to 10% of total brain mercury was lost by formalin fixation. Brain inorganic mercury in the patient ranged from 82 to 100%. Since inorganic mercury crosses the blood-brain barrier poorly, biotransformation of methyl to inorganic mercury may have occurred after methylmercury crossed the blood-brain barrier, accounting for its persistence in brain and causing part of the brain damage. PMID:8210224

  16. Bacterial methylmercury degradation in Florida Everglades peat sediment

    SciTech Connect

    Marvin-Dipasquale, M.C.; Oremland, R.S.

    1998-09-01

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying {sup 14}CH{sub 4} and {sup 14}CO{sub 2} production after incubation of anaerobic sediments with [{sup 14}C]MeHg. Degradation rate constants (k) were consistently {le}0.1 d{sup {minus}1} and decreased with sediment depth. Higher k values were observed when shorter incubation times and lower MeHg amendment levels were used, and k increased 2-fold as in-situ MeHg concentrations were approached. The average floc layer k was 0.046 {+-} 0.023 d{sup {minus}1} (n = 17) for 1--2 day incubations. In-situ degradation rates were estimated to be 0.02--0.5 ng of MeHg (g of dry sediment){sup {minus}1} d{sup {minus}1}, increasing from eutrophied to pristine areas. Nitrate-respiring bacteria did not demethylate MeHg, and NO{sub 3}{sup {minus}} addition partially inhibited degradation in some cases. MeHg degradation rates were not affected by PO{sub 4}{sup 3{minus}} addition. {sup 14}CO{sub 2} production in all samples indicated that oxidative demethylation (OD) was an important degradation mechanism. OD occurred over 5 orders of magnitude of applied MeHg concentration, with lowest limits in the range of in-situ MeHg levels. Sulfate reducers and methanogens were the primary agents of anaerobic OD, although it is suggested that methanogens dominate degradation at in-situ MeHg concentrations. Specific pathways of OD by these two microbial groups are proposed.

  17. Effects of diphenyl diselenide on methylmercury toxicity in rats.

    PubMed

    Dalla Corte, Cristiane L; Wagner, Caroline; Sudati, Jéssie H; Comparsi, Bruna; Leite, Gerlania O; Busanello, Alcindo; Soares, Félix A A; Aschner, Michael; Rocha, João B T

    2013-01-01

    This study investigates the efficacy of diphenyl diselenide [(PhSe)2] in attenuating methylmercury- (MeHg-)induced toxicity in rats. Adult rats were treated with MeHg [5 mg/kg/day, intragastrically (i.g.)] and/ or (PhSe)2 [1 mg/kg/day, intraperitoneally (i.p.)] for 21 days. Body weight gain and motor deficits were evaluated prior to treatment, on treatment days 11 and 21. In addition, hepatic and cerebral mitochondrial function (reactive oxygen species (ROS) formation, total and nonprotein thiol levels, membrane potential (ΔΨm), metabolic function, and swelling), hepatic, cerebral, and muscular mercury levels, and hepatic, cerebral, and renal thioredoxin reductase (TrxR) activity were evaluated. MeHg caused hepatic and cerebral mitochondrial dysfunction and inhibited TrxR activity in liver (38,9%), brain (64,3%), and kidney (73,8%). Cotreatment with (PhSe)2 protected hepatic and cerebral mitochondrial thiols from depletion by MeHg but failed to completely reverse MeHg's effect on hepatic and cerebral mitochondrial dysfunction or hepatic, cerebral, and renal inhibition of TrxR activity. Additionally, the cotreatment with (PhSe)2 increased Hg accumulation in the liver (50,5%) and brain (49,4%) and increased the MeHg-induced motor deficits and body-weight loss. In conclusion, these results indicate that (PhSe)2 can increase Hg body burden as well as the neurotoxic effects induced by MeHg exposure in rats. PMID:24459674

  18. Hair as a retrospective calendar of cortisol production-Increased cortisol incorporation into hair in the third trimester of pregnancy.

    PubMed

    Kirschbaum, Clemens; Tietze, Antje; Skoluda, Nadine; Dettenborn, Lucia

    2009-01-01

    Hair has long been used in toxicology, forensic science, doping control and other fields as a biological specimen for the detection of environmental agents, drugs, or toxins. Most recent evidence suggests that also hormones are incorporated and trapped inside the growing hair. This has led to the hypothesis that cortisol measurement of distinct hair segments could provide a retrospective calendar of cortisol production for the individual. In this first proof-of-concept study in humans, we analyzed cortisol in hair donated by mothers with a neonate child (n-Mothers; N=103), mothers with toddlers 3-9 months of age (t-Mothers; N=19), and control women (N=20). We cut hair strands from each women into at least three 3-cm segments, which, based on an average hair growth rate of 1cm per month, would represent hair grown over the past three, six, and nine months, respectively. Since in the third trimester of pregnancy there is a well-documented increased production of cortisol, we expected to see elevated levels of cortisol in the most proximal hair segment of women who had just given birth to a child (n-Mothers) compared with the control women. Likewise, we expected to see elevated levels in the second, third, or fourth segment of mothers of 3-month olds, 6-months olds, and 9-months olds, respectively. These hair segments, cut at 4-12 cm from the scalp, would represent hair grown throughout the third trimester of pregnancy. Results showed that there was a strong monotonic decline in cortisol concentration from the segment closest to the scalp to the most distal hair segment (p<0.0001). Cortisol levels decreased by 30-40% from one segment to the next for the most recent four hair segments. Segments from hair older than one year had similarly, low levels of cortisol. Comparisons of cortisol levels in hair between n-Mothers and control women yielded the expected results: cortisol levels in the first 3-cm hair segment (i.e., closest to the scalp) of n-Mothers were two

  19. Extraction and Analysis of Cortisol from Human and Monkey Hair

    PubMed Central

    Meyer, Jerrold; Novak, Melinda; Hamel, Amanda; Rosenberg, Kendra

    2014-01-01

    The stress hormone cortisol (CORT) is slowly incorporated into the growing hair shaft of humans, nonhuman primates, and other mammals. We developed and validated a method for CORT extraction and analysis from rhesus monkey hair and subsequently adapted this method for use with human scalp hair. In contrast to CORT "point samples" obtained from plasma or saliva, hair CORT provides an integrated measure of hypothalamic-pituitary-adrenocortical (HPA) system activity, and thus physiological stress, during the period of hormone incorporation. Because human scalp hair grows at an average rate of 1 cm/month, CORT levels obtained from hair segments several cm in length can potentially serve as a biomarker of stress experienced over a number of months. In our method, each hair sample is first washed twice in isopropanol to remove any CORT from the outside of the hair shaft that has been deposited from sweat or sebum. After drying, the sample is ground to a fine powder to break up the hair's protein matrix and increase the surface area for extraction. CORT from the interior of the hair shaft is extracted into methanol, the methanol is evaporated, and the extract is reconstituted in assay buffer. Extracted CORT, along with standards and quality controls, is then analyzed by means of a sensitive and specific commercially available enzyme immunoassay (EIA) kit. Readout from the EIA is converted to pg CORT per mg powdered hair weight. This method has been used in our laboratory to analyze hair CORT in humans, several species of macaque monkeys, marmosets, dogs, and polar bears. Many studies both from our lab and from other research groups have demonstrated the broad applicability of hair CORT for assessing chronic stress exposure in natural as well as laboratory settings. PMID:24513702

  20. Extraction and analysis of cortisol from human and monkey hair.

    PubMed

    Meyer, Jerrold; Novak, Melinda; Hamel, Amanda; Rosenberg, Kendra

    2014-01-01

    The stress hormone cortisol (CORT) is slowly incorporated into the growing hair shaft of humans, nonhuman primates, and other mammals. We developed and validated a method for CORT extraction and analysis from rhesus monkey hair and subsequently adapted this method for use with human scalp hair. In contrast to CORT "point samples" obtained from plasma or saliva, hair CORT provides an integrated measure of hypothalamic-pituitary-adrenocortical (HPA) system activity, and thus physiological stress, during the period of hormone incorporation. Because human scalp hair grows at an average rate of 1 cm/month, CORT levels obtained from hair segments several cm in length can potentially serve as a biomarker of stress experienced over a number of months. In our method, each hair sample is first washed twice in isopropanol to remove any CORT from the outside of the hair shaft that has been deposited from sweat or sebum. After drying, the sample is ground to a fine powder to break up the hair's protein matrix and increase the surface area for extraction. CORT from the interior of the hair shaft is extracted into methanol, the methanol is evaporated, and the extract is reconstituted in assay buffer. Extracted CORT, along with standards and quality controls, is then analyzed by means of a sensitive and specific commercially available enzyme immunoassay (EIA) kit. Readout from the EIA is converted to pg CORT per mg powdered hair weight. This method has been used in our laboratory to analyze hair CORT in humans, several species of macaque monkeys, marmosets, dogs, and polar bears. Many studies both from our lab and from other research groups have demonstrated the broad applicability of hair CORT for assessing chronic stress exposure in natural as well as laboratory settings. PMID:24513702

  1. Preoperative hair removal.

    PubMed

    Hamilton, H W; Hamilton, K R; Lone, F J

    1977-05-01

    This study compares the efficiency, safety and cost of hair removal before surgery, with a safety razor, an electric clipper and a depilatory. It was found that both the razor and the clipper damaged the surface of the skin, while the depilatory caused a mild lymphocytic reaction in the upper dermis. The depilatory was expensive and may cause sensitivity reactions in a few individuals, but was found to be the easiest and most efficient method of removing hair. It was concluded that if hair has to be removed a depilatory is the agent of choice. PMID:870157

  2. Hair and scalp dermatoscopy.

    PubMed

    Miteva, Mariya; Tosti, Antonella

    2012-11-01

    Dermatoscopy is a noninvasive diagnostic tool that allows the recognition of morphologic structures not visible by the naked eye. Trichoscopy (scalp dermatoscopy and videodermatoscopy) is useful for the diagnosis and follow-up of hair and scalp disorders. However, it is not widely used in the management of hair disorders. This review provides updated information from the literature and our experience on the dermoscopic features of the most common hair and scalp disorders. This will enable dermatologists to make fast diagnoses of tinea capitis and alopecia areata, distinguish early androgenetic alopecia from telogen effluvium, and differentiate scarring from nonscarring alopecia. PMID:22405573

  3. Content of heavy metals in the hair

    NASA Astrophysics Data System (ADS)

    Patrashkov, S. A.; Petukhov, V. L.; Korotkevich, O. S.; Petukhov, I. V.

    2003-05-01

    The aim of our investigation was to determine of HM content in the hair of people and animals. Two of the main essential elements-Zn and Cu and two of the supertoxical heavy metals- Pb and Cd were chosen. The investigations were conducted in Russian Federation and Belarus Republic in 2001-2002. About 500 hair samples of people, dogs, cats, cattle, horses, yaks, pigs, sheep goats and rabbits were studied by the stripping voltammetric analysis (SVA) method with TA- 2 analyzer to determine Zn, Cu, Pb and Cd concentrations. The hair samples were prepared according to the methods developed in Tomsk University (Russia) and improved by the authors. The essence of the methods is the multiconsecutive burning of hair samples to ashes and boiling them in concentrated acids to dissolve chemical combinations and transform their metals into ion forms. The zinc concentration was the highest in all hair samples (58.65 ... 195.15 mg/kg). The copper content was several times less (5.49 ... 22.63 mg/kg). Lead and cadmium were detected in relatively low amounts (0.32 ... 2.42 mg/kg and 0.04 ... 0.92 mg/kg respectively). The highest Pb and Cd levels were detected in cats and people hair.

  4. Neurodevelopment of Amazonian children exposed to ethylmercury (from Thimerosal in vaccines) and methylmercury (from fish).

    PubMed

    Marques, Rejane C; Abreu, Luciana; Bernardi, José V E; Dórea, José G

    2016-08-01

    Few studies have addressed co-occurring methylmercury (MeHg) from maternal origin and ethylmercury (EtHg) from Thimerosal-containing vaccines (TCVs) during infant's neurodevelopment. We studied children (n=1139) from the Western Amazon based on combined (low, intermediate, and high) exposure to chronic MeHg from fish consumption and acute TCV- EtHg. Neurodevelopment outcomes were age of walking and age of talking, and the Bayley Scale of Infant Development (BSID). The Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) were measured at six and 24 months of age. Median hair-Hg (HHg) at birth was 6.4µgg(-1) in mothers, and 1.94µgg(-1) in newborns; total (pregnancy and infancy) EtHg exposure ranged from 0 to 187.5µg. The combined (MeHg+EtHg) exposure showed significant differences for MDI but not for PDI; however, there was a significant decrease in both MDI and PDI scores at 24 months. The increase in BSID delays (scores <80) between six and 24 months was not discernible with regards to EtHg or MeHg exposure. We found a statistically significant increase in neurodevelopmental (BSID) delays related to the combined exposure to Hg (MeHg>EtHg). Neurodevelopment delays due to low-doses of organic mercury (albeit undiscernible) are not predictable but can be avoided by choosing low-Hg fish and providing Thimerosal-free vaccines. PMID:26774584

  5. A Physiologically Based Model for Methylmercury in Female American Kestrels

    EPA Science Inventory

    A physiologically based toxicokinetic (PBTK) model was developed to describe the uptake, distribution, and elimination of methylmercury (CH3Hg) in female American kestrels. The model consists of six tissue compartments corresponding to the brain, liver, kidney, gut, red blood cel...

  6. Transfer of methylmercury to hens' eggs after oral administration

    SciTech Connect

    Kambamanoli-Dimou, A. ); Kamarianos, A.; Kilikidis, S. )

    1991-01-01

    The present investigation was performed to elucidate the possibility of transport of methylmercury into eggs after its oral administration. Also, to determine the quantity of mercury excreted via eggs after oral administration of a certain quantity of this element once or in doses.

  7. The Engineered Phytoremediation of Ionic and Methylmercury Pollution

    SciTech Connect

    Richard Meagher; Sarah Marshburn; Andrew Heaton; Anne Marie Zimer; Raoufa Rahman

    2003-06-24

    Our current specific objectives are to use transgenic plants to control the chemical species, electrochemical state, and above ground binding of mercury to (a) prevent methylmercury from entering the food-chain, (b) remove mercury from polluted sites, and (c) hyperaccumulate mercury in above ground tissues for later harvest.

  8. ETHYLMERCURY: FORMATION IN PLANT TISSUES AND RELATION TO METHYLMERCURY FORMATION

    EPA Science Inventory

    Seedlings of the common dwarf garden pea, Pisum sativum, cv. Little Marvel, exposed to elemental mercury vapor formed both methylmercury and ethylmercury in all parts of the plant. Concentrations of both organomercury compounds fluctuated considerably over a 48-hour exposure peri...

  9. BACTERIAL METHYLMERCURY DEGRADATION IN FLORIDA EVERGLADES PEAT SEDIMENT

    EPA Science Inventory

    Methylmercury (MeHg) degradation was investigated along an eutrophication gradient in the Florida Everglades by quantifying 14CH4 and 14CO2 production after incubation of anaerobic sediments with [14C]MeHg. Degradation rate constants (k) were consistently <=0.1 d-1 and decreased ...

  10. Impact of hair-care products on FAEE hair concentrations in substance abuse monitoring.

    PubMed

    Gareri, Joey; Appenzeller, Brice; Walasek, Paula; Koren, Gideon

    2011-04-01

    Previous studies have indicated that the use of high-ethanol-content (>65%) hair-care products may elevate fatty acid ethyl ester (FAEE) concentrations in hair. In this case series, nine individuals were identified by FAEE analysis to be chronic alcohol abusers in the context of child-welfare substance abuse monitoring. Based on patient claims of moderate or no alcohol consumption, the presence of ethanol in the patients' hair-care regimens was investigated. Samples were additionally tested for the presence of ethyl glucuronide (EtG). From a total of nine patients, 12 hair samples were submitted for analysis. Patient histories were obtained as well as Material Safety Data Sheets (MSDS) listing hair-care product ethanol content. Hair samples were pre-washed to remove external contamination and analyzed for FAEE and EtG by GC-MS. According to the Society of Hair Testing consensus guidelines, FAEE levels exceeding 0.50 ng/mg and/or EtG levels exceeding 30 pg/mg indicate chronic excessive alcohol consumption. Upon initial analysis, the nine samples exhibited positive FAEE findings ranging from 0.496 to 4.984 ng/mg. MSDS review revealed the presence of ethanol from 10% to 95% by volume in at least one hair-care product used by each individual. Results of the EtG analysis ranged from 1.9 to 23.5 pg/mg. These findings indicate that regular use of products with ethanol content as low as 10% can impact FAEE results. EtG analysis should be used to confirm FAEE findings and appears to be unaffected by hair-care products, likely due to alternative mechanisms of incorporation. PMID:21301822

  11. Hox in hair growth and development

    NASA Astrophysics Data System (ADS)

    Awgulewitsch, Alexander

    2003-05-01

    of great functional diversity in hair that require complex transcriptional control mechanisms to ensure proper spatio-temporal patterns of Hox gene expression at homeostatic levels.

  12. Relation of Prenatal Methylmercury Exposure from Environmental Sources to Childhood IQ

    PubMed Central

    Muckle, Gina; Ayotte, Pierre; Dewailly, Éric

    2015-01-01

    Background Although prenatal methylmercury exposure has been linked to poorer intellectual function in several studies, data from two major prospective, longitudinal studies yielded contradictory results. Associations with cognitive deficits were reported in a Faroe Islands cohort, but few were found in a study in the Seychelles Islands. It has been suggested that co-exposure to another contaminant, polychlorinated biphenyls (PCBs), may be responsible for the positive findings in the former study and that co-exposure to nutrients in methylmercury-contaminated fish may have obscured and/or protected against adverse effects in the latter. Objectives We aimed to determine the degree to which co-exposure to PCBs may account for the adverse effects of methylmercury and the degree to which co-exposure to docosahexaenoic acid (DHA) may obscure these effects in a sample of Inuit children in Arctic Québec. Methods IQ was estimated in 282 school-age children from whom umbilical cord blood samples had been obtained and analyzed for mercury and other environmental exposures. Results Prenatal mercury exposure was related to poorer estimated IQ after adjustment for potential confounding variables. The entry of DHA into the model significantly strengthened the association with mercury, supporting the hypothesis that beneficial effects from DHA intake can obscure adverse effects of mercury exposure. Children with cord mercury ≥ 7.5 μg/L were four times as likely to have an IQ score < 80, the clinical cut-off for borderline intellectual disability. Co-exposure to PCBs did not alter the association of mercury with IQ. Conclusions To our knowledge, this is the first study to document an association of prenatal mercury exposure with poorer performance on a school-age assessment of IQ, a measure whose relevance for occupational success in adulthood is well established. This association was seen at levels in the range within which many U.S. children of Asian-American background are

  13. Advances in Understanding Hair Growth.

    PubMed

    Bernard, Bruno A

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a "Yin Yang" type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  14. Taphonomy of hair--a study of postmortem root banding.

    PubMed

    Koch, Sandra L; Michaud, Amy L; Mikell, Carmenza E

    2013-01-01

    Although it has been generally accepted within the forensic hair community that decompositional changes in the form of an identifiable banding pattern can occur in the root area of hairs after death, little detailed information with regard to this phenomenon is known (e.g., rates at which this occurs and conditions that cause this banding). Hairs were collected daily from bodies placed in water, an air-conditioned environment, an enclosed vehicle, on the surface of the ground, and buried at the University of Tennessee Forensic Anthropology Center. The hairs were examined microscopically and the level of change documented for each environment. The onset of the banding was observed to have been delayed in water, air-conditioning, and cold weather and was hastened by warm weather and within the vehicle. This study provides validation that decomposition does produce varying effects on hair at the proximal portion of a hair root, including a dark band. PMID:23013230

  15. Photolytic degradation of methylmercury enhanced by binding to natural organic ligands

    NASA Astrophysics Data System (ADS)

    Zhang, Tong; Hsu-Kim, Heileen

    2010-07-01

    Methylmercury is a neurotoxin that accumulates in food webs and poses a significant risk to human health. In natural water bodies, methylmercury concentrations remain low due to the degradation of methylmercury into inorganic mercury by sunlight, a process known as photodecomposition. Rates of photodecomposition are relatively rapid in freshwater lakes, and slow in marine waters, but the cause of this difference is not clear. Here, we carry out incubation experiments with artificial freshwater and seawater samples to examine the mechanisms regulating methylmercury photodecomposition. We show that singlet oxygen-a highly reactive form of dissolved oxygen generated by sunlight falling on dissolved organic matter-drives photodecomposition. However, in our experiments the rate of methylmercury degradation depends on the type of methylmercury-binding ligand present in the water. Relatively fast degradation rates (similar to observations in freshwater lakes) were detected when methylmercury species were bound to sulphur-containing ligands such as glutathione and mercaptoacetate. In contrast, methylmercury-chloride complexes, which are the dominant form of methylmercury in marine systems, did not degrade as easily. Our results could help to explain why methylmercury photodecomposition rates are relatively rapid in freshwater lakes and slow in marine waters.

  16. Lead and cadmium concentrations in the hair of fishermen from the Subae River basin, Brazil

    SciTech Connect

    Carvalho, F.; Tavares, T.M.; Souza, S.P.; Linhares, P.S.

    1984-04-01

    Previous studies have shown heavy pollution by lead and cadmium in the Subae River basin, State of Bahia, Brazil, caused by a lead smelter. Concentrations of these metals were determined in scalp hair of fishermen from three riverside towns and from a reference town. Increased levels for both metals were associated with increasing proximity to the smelter. Mean concentrations of lead and cadmium were higher among fishermen with straight hair than among those with curly hair. The effects of hair washing, hair type, and color and age on metal concentrations in fishermen's hair were studied.

  17. Vulnerability of dorsal root neurons and fibers toward methylmercury toxicity: a morphological evaluation

    SciTech Connect

    Yip, R.K.; Chang, L.W.

    1981-10-01

    The selective and relative sensitivity of various components (dorsal root neurons, dorsal root fibers, and ventral root fibers) of the dorsal root ganglia toward methylmercury toxicity were investigated. Charles River rats were orally administered methymercury chloride at a daily dose of 2.0 mg/kg body wt for 8 weeks. Dorsal root ganglia (L/sub 1/-S/sub 1/) were examined with light and electron microscopy. Extensive Wallerian-like degeneration was observed in the dorsal root fibers while no significant changes were found in the dorsal root neurons and in the ventral root fibers at the light-microscopic level. At the electron-microscopic level, only minor and possibly reversible changes, such as increase in lysosomes, neurofilamentous proliferation, and disintegration of the Nissl substance, were observed in the neuronal cell bodies while severe and irreversible degenerative changes occurred in the dorsal root fibers. No remarkable pathological changes were observed in the ventral root fibers. Schwann cells became hypertrophied and transformed into actively phagocytosing macrophages. It is concluded that while the dorsal root ganglia are highly vulnerable to the toxicity of methylmercury, the relative sensitivity to the toxic impact is: dorsal root fiber > dorsal root neuron (nerve cell body) > ventral root fibers.

  18. Scurvy, corkscrew hair (image)

    MedlinePlus

    Scurvy is a nutritional disease caused by deficiency of vitamin C. Pinpoint bleeding around hair follicles, and " ... this picture, can occur as a result of scurvy. Bleeding along the gums is common. This disease ...

  19. Hair Treatments and Pregnancy

    MedlinePlus

    ... is likely that only a small amount of hair straightening products are actually absorbed into your system, so the developing baby would only be exposed to small amounts. I work full time as a cosmetologist and recently became ...

  20. Hair Loss (Alopecia)

    MedlinePlus

    ... for these devices are not known. Prescription medicine Finasteride: The FDA approved this medicine to treat men ... hair re-growth in many (about 66%) men. Finasteride works by stopping the body from making a ...

  1. Selenomethionine reduces visual deficits due to developmental methylmercury exposures

    PubMed Central

    Weber, Daniel N.; Connaughton, Victoria P.; Dellinger, John A.; Klemer, David; Udvadia, Ava; Carvan, Michael J.

    2008-01-01

    Developmental exposures to methylmercury (MeHg) have life-long behavioral effects. Many micronutrients, including selenium, are involved in cellular defenses against oxidative stress and may reduce the severity of MeHg-induced deficits. Zebrafish embryos (<4 hours post fertilization, hpf) were exposed to combinations of 0.0-0.30 μM MeHg and/or selenomethionine (SeMet) until 24 hpf then placed in clean medium. Fish were tested as adults under low light conditions (~60 μW/m2) for visual responses to a rotating black bar. Dose-dependent responses to MeHg exposure were evident (ANOVA, P<0.001) as evidenced by reduced responsiveness, whereas SeMet did not induce deficits except at 0.3 μM,. Ratios of SeMet:MeHg of 1:1 or 1:3 resulted in responses that were indistinguishable from controls (ANOVA, P<0.001). No gross histopathologies were observed (H&E stain) in the retina or optic tectum at any MeHg concentration. Whole-cell, voltage-gated, depolarization-elicited outward K+ currents of bipolar cells in intact retina of slices adult zebrafish were recorded and outward K+ current amplitude was larger in bipolar cells of MeHg-treated fish. This was due to the intense response of cells expressing the delayed rectifying IK current; cells expressing the transient IA current displayed a slight trend for smaller amplitude among MeHg-treated fish. Developmental co-exposure to SeMet reduced but did not eliminate the increase in the MeHg-induced IK response, however, IA responses increased significantly over MeHg-treated fish to match control levels. Electrophysiological deficits parallel behavioral patterns in MeHg-treated fish, i.e., initial reactions to the rotating bar were followed by periods of inactivity and then a resumption of responses. PMID:17905328

  2. Comparative toxicogenomic responses of mercuric and methyl-mercury

    PubMed Central

    2013-01-01

    Background Mercury is a ubiquitous environmental toxicant that exists in multiple chemical forms. A paucity of information exists regarding the differences or similarities by which different mercurials act at the molecular level. Results Transcriptomes of mixed-stage C. elegans following equitoxic sub-, low- and high-toxicity exposures to inorganic mercuric chloride (HgCl2) and organic methylmercury chloride (MeHgCl) were analyzed. In C. elegans, the mercurials had highly different effects on transcription, with MeHgCl affecting the expression of significantly more genes than HgCl2. Bioinformatics analysis indicated that inorganic and organic mercurials affected different biological processes. RNAi identified 18 genes that were important in C. elegans response to mercurial exposure, although only two of these genes responded to both mercurials. To determine if the responses observed in C. elegans were evolutionarily conserved, the two mercurials were investigated in human neuroblastoma (SK-N-SH), hepatocellular carcinoma (HepG2) and embryonic kidney (HEK293) cells. The human homologs of the affected C. elegans genes were then used to test the effects on gene expression and cell viability after using siRNA during HgCl2 and MeHgCl exposure. As was observed with C. elegans, exposure to the HgCl2 and MeHgCl had different effects on gene expression, and different genes were important in the cellular response to the two mercurials. Conclusions These results suggest that, contrary to previous reports, inorganic and organic mercurials have different mechanisms of toxicity. The two mercurials induced disparate effects on gene expression, and different genes were important in protecting the organism from mercurial toxicity. PMID:24118919

  3. Binding Strength of Methylmercury to Aquatic NOM

    SciTech Connect

    Khwaja, A.; Bloom, P; Brezonik, P

    2010-01-01

    A competitive-ligand, equilibrium-dialysis technique using bromide measured methylmercury (MeHg{sup +}) binding to Suwannee River fulvic acid (SRFA) and NOM from a lake and a bog in Minnesota. Distribution coefficients (K{sub OC}) and stability constants (K{prime}) varied only slightly over a range of [Br{sup -}] and ratios of MeHg{sup +} to reduced sulfur, S{sub re}, the putative NOM binding site. For SRFA at pH 3.0, K{sub OC} ranged from 10{sup 7.7} to 10{sup 8.2} and K{prime} ranged from 10{sup 15.5} to 10{sup 16.0} over MeHg{sup +}:S{sub re} ratios from 1:1220 to 1:12200 (well below S{sub re} saturation). The importance of pH depends on the calculation model for binding constants. Over pH 2.98-7.62, K{sub OC} had little pH dependence (slope = 0.2; r{sup 2} = 0.4; range 10{sup 7.7}-10{sup 9.1}), but K{prime} calculated using thiol ligands with pK{sub a} = 9.96 had an inverse relationship (slope = -0.8; r{sup 2} = 0.9; range 10{sup 15.6}-10{sup 12.3}). A pH-independent model was obtained only with thiol pK{sub a} {le} 4. The mean K{prime}{sub 4} for SRFA (K{prime} with thiol pK{sub a} = 4.2) was 10{sup 9.8} (range 10{sup 9.11}-10{sup 10.27}) and small slope (0.02). Similar values were found for Spring Lake NOM; bog S2 NOM had values one-tenth as large. These constants are generally similar to published values; differences reflect variations in methods, pH, types of NOM, and calculation models.

  4. Mercury residues in tissues of dead and surviving birds fed methylmercury

    USGS Publications Warehouse

    Finley, M.T.; Stickel, W.H.; Christensen, R.E.

    1979-01-01

    Concentrations of mercury in passerine birds fed diets containing 40 ppm methylmercury were similar in tissues of birds that died from mercury poisoning and in those that were sacrificed after half the group had died. Residues were higher in tissues of birds that died, but the differences were not statistically significant. Residue levels were highest in livers, followed by kidneys and brains. Levels of mercury were similar in breast muscle, carcass, and whole body. Mercury levels were highest in redwinged blackbirds, lowest in grackles, and intermediate in starlings and cowbirds. Mercury concentrations exceeded 20 ppm in all tissues of all species and were similar to levels reported in wild birds known to have died of mercury poisoning.

  5. Hair as a Biomarker of Environmental Manganese Exposure

    PubMed Central

    Eastman, Rachel R.; Jursa, Tom P.; Benedetti, Chiara; Lucchini, Roberto G.; Smith, Donald R.

    2013-01-01

    The absence of well-validated biomarkers of manganese (Mn) exposure in children remains a major obstacle for studies of Mn toxicity. We developed a hair cleaning methodology to establish the utility of hair as an exposure biomarker for Mn and other metals (Pb, Cr, Cu), using ICP-MS, scanning electron microscopy, and laser ablation ICP-MS to evaluate cleaning efficacy. Exogenous metal contamination on hair that was untreated or intentionally contaminated with dust or Mn-contaminated water was effectively removed using a cleaning method of 0.5% Triton X-100 sonication plus 1N nitric acid sonication. This cleaning method was then used on hair samples from children (n=121) in an ongoing study of environmental Mn exposure and related health effects. Mean hair Mn levels were 0.121 μg/g (median = 0.073 μg/g, range = 0.011 – 0.736 μg/g), which are ~4 to 70-fold lower than levels reported in other pediatric Mn studies. Hair Mn levels were also significantly higher in children living in the vicinity of active, but not historic, ferroalloy plant emissions compared to controls (P<0.001). These data show that exogenous metal contamination on hair can be effectively cleaned of exogenous metal contamination, and they substantiate the use of hair Mn levels as a biomarker of environmental Mn exposure in children. PMID:23259818

  6. 7. CONVEYOR DISCHARGE IN HOG HAIR PROCESSING AREA, NORTHWEST CORNER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. CONVEYOR DISCHARGE IN HOG HAIR PROCESSING AREA, NORTHWEST CORNER OF LEVEL 2; HAIR WAS TRANSPORTED BY CONVEYOR FROM BUILDING 40, THEN WASHED, DRIED AND BALED IN BUILDING 148 - Rath Packing Company, Grease Interceptor Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  7. Hair Mineral Content as a Predictor of Learning Disabilities.

    ERIC Educational Resources Information Center

    Marlowe, Mike; And Others

    1984-01-01

    This study investigated the relationship between hair mineral elements and childhood learning disabilities and determined which minerals, if any, separated 26 learning disabled children with 24 normal controls. The learning disabled group had significantly raised hair-lead concentrations. There were also differences in the mean levels of 10 other…

  8. Developmental selenomethionine and methylmercury exposures affect zebrafish learning

    PubMed Central

    Smith, Leigh E.; Carvan, Michael J.; Dellinger, John A.; Ghorai, Jugal K.; White, Donald B.; Williams, Frederick E.; Weber, Daniel N.

    2009-01-01

    Methylmercury (MeHg) is a ubiquitous environmental pollutant and has been shown to affect learning in vertebrates following relatively low exposures. Zebrafish were used to model long-term learning deficits after developmental MeHg exposure. Selenomethionine (SeMet) co-exposure was used to evaluate its role in neuroprotection. Embryos were exposed from 2–24 hours post fertilization to (1) MeHg without SeMet, (2) SeMet without MeHg and (3) in combination of MeHg and SeMet. In case (1), the levels of MeHg were 0.00, 0.01, 0.03, 0.06, 0.10, 0.30 µM. In case (2), the levels of SeMet were 0.00. 0.03, 0.06, 0.10, 0.30 µM. In case (3), co-exposure levels of (MeHg, SeMet) were (0.03, 0.03), (0.03, 0.06), (0.03, 0.10), (0.03, 0.30), (0.10, 0.03), (0.10, 0.06), (0.10, 0.10), (0.10, 0.30) µM. Learning functions were tested in individual adults, four months after developmental exposure using a spatial alternation paradigm with food delivery on alternating sides of the aquarium. Low levels of MeHg (<0.1 µM) exposure delayed learning in treated fish; fish exposed to higher MeHg levels were unable to learn the task; SeMet co-exposure did not prevent this deficit. These data are consistent with findings in laboratory rodents. The dorsal and lateral telencephalon are the primary brain regions in fish involved in spatial learning and memory. Adult telencephalon cell body density decreased significantly at all MeHg exposures >0.01 µM MeHg. SeMet co-exposure ameliorated but did not prevent changes in telencephalon cell body density. In summary, MeHg affected both learning and brain structure, but SeMet only partially reversed the latter. PMID:19800969

  9. Mercury in scalp hair of healthy Singapore residents.

    PubMed

    Foo, S C; Ngim, C H; Phoon, W O; Lee, J

    1988-06-15

    Two hundred and twenty-five hair samples (150 Chinese, 44 Malays and 31 Indians) from healthy residents not occupationally exposed to mercury were analyzed by cold vapour atomic absorption spectrophotometry to determine their total, inorganic and organic mercury levels. The arithmetic means of total mercury levels in hair were 6.1, 5.2 and 5.4 ppm for the Chinese, Malays and Indians, respectively. Factors contributing to the amount of mercury in hair, including consumption of fish and marine products, use of traditional ethnic medicines, artificial hair waving, age, sex and ethnicity were analyzed. Fish consumption, sex and ethnicity are factors found to contribute significantly (p less than 0.05) to mercury levels in hair. PMID:3406725

  10. Mercury and methylmercury concentrations in Mediterranean seafood and surface sediments, intake evaluation and risk for consumers.

    PubMed

    Spada, Lucia; Annicchiarico, Cristina; Cardellicchio, Nicola; Giandomenico, Santina; Di Leo, Antonella

    2012-04-01

    Total mercury and methylmercury concentrations were measured in sediments and marine organisms from the Taranto Gulf to understand their distribution and partitioning. Sediment concentrations ranged from 0.036 to 7.730 mg/kg (mean: 2.777 mg/kg d.w.) and from 1 to 40 μg/kg (mean: 11 μg/kg d.w.) for total mercury (THg) and methylmercury (Me-Hg), respectively. In mollusks THg ranged from n.d. to 1870 μg/kg d.w. while in fish from 324 to 1740 μg/kg d.w. Me-Hg concentrations in fish ranged from 190 to 1040 μg/kg d.w. and from n.d. to 1321 μg/kg d.w. in mollusks. THg exceeded the maximum level fixed by the European Commission (0.5 mg/kg w.w.) only in gastropod Hexaplex t. The calculated weekly intake was in many cases over the Provisional Tolerable Weekly Intake established by EFSA for all edible species. These results seem to indicate that dietary consumption of this seafood implicates an appreciable risk for human health. PMID:21968333

  11. [The effects of methylmercury on health in children and adults; national and international studies].

    PubMed

    González-Estecha, Montserrat; Bodas-Pinedo, Andrés; Rubio-Herrera, Miguel Ángel; Martell-Claros, Nieves; Trasobares-Iglesias, Elena M; Ordóñez-Iriarte, José M; Guillén-Pérez, José Jesús; Herráiz-Martínez, Miguel Ángel; García-Donaire, José Antonio; Farré-Rovira, Rosaura; Calvo-Manuel, Elpidio; Martínez-Álvarez, Jesús Román; Llorente-Ballesteros, M Teresa; Sáinz-Martín, María; Martínez-Astorquiza, Txantón; Martínez-García, M José; Bretón Lesmes, Irene; Cuadrado-Cenzual, M Ángeles; Prieto-Menchero, Santiago; Gallardo-Pino, Carmen; Moreno-Rojas, Rafael; Bermejo-Barrera, Pilar; Torres-Moreno, Miriam; Arroyo-Fernández, Manuel; Calle-Pascual, Alfonso

    2014-01-01

    The benefit of fish consumption in children and adults is well-known. However, it has been pointed out that excessive methylmercury intake due to consumption of contaminated fish leads to neurological toxicity in children, affecting cognitive function, memory, visual-motor function and language. After the intoxications in Minamata and Iraq, wide-ranging epidemiological studies were carried out in New Zealand, the Faroe Islands and the Seychelles and international recommendations were established for fish consumption in pregnant women and small children. In Spain, the Childhood and Environmental project (INMA, its Spanish acronym) has studied the effects of diet and the environment on fetal and childhood development in different geographic areas of Spain. National and international sudies have demonstrated that mercury concentrations are mainly dependent on fish consumption, although there are variations among countries which can be explained not only by the levels of fish consumption, but also by the type or species of fish that is consumed, as well as other factors. Although the best documented adverse effects of methylmercury are the effects on nervous sytem development in fetuses and newborns, an increasing number of studies indicate that cognitive function, reproduction and, especially, cardiovascular risk in the adult population can also be affected. However, more studies are necessary in order to confirm this and establish the existance of a causal relationship. PMID:25365002

  12. Methylmercury in water, sediment, and invertebrates in created wetlands of Rouge Park, Toronto, Canada.

    PubMed

    Sinclair, Kathleen A; Xie, Qun; Mitchell, Carl P J

    2012-12-01

    Thousands of hectares of wetlands are created annually because wetlands provide beneficial ecosystem services. Wetlands are also key sites for production of the bioaccumulative neurotoxin methylmercury (MeHg), but little is known about MeHg production in created systems. Here, we studied methylmercury in sediment, water, and invertebrates in created wetlands of various ages. Sediment MeHg reached 8 ng g(-1) in the newest wetland, which was significantly greater than in natural, control wetlands. This trend was mirrored in several invertebrate taxa, whose concentrations reached as high as 1.6 μg g(-1) in the newest wetland, above levels thought to affect reproduction in birds. The MeHg concentrations in created wetland invertebrate taxa generally decreased with increasing wetland age, possibly due to a combination of deeper anoxia and less organic matter accumulation in younger wetlands. A short-term management intervention and/or improved engineering design may be necessary to reduce the mercury-associated risk in newly created wetlands. PMID:22940274

  13. Species differences in the sensitivity of avian embryos to methylmercury

    USGS Publications Warehouse

    Heinz, G.H.; Hoffman, D.J.; Klimstra, J.D.; Stebbins, K.R.; Kondrad, S.L.; Erwin, C.A.

    2009-01-01

    We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC50). Based on the dose-response curves and LC50s, we ranked species according to their sensitivity to injected methylmercury. Although the previously published embryotoxic threshold of mercury in game farm mallards (Anas platyrhynchos) has been used as a default value to protect wild species of birds, we found that, relative to other species, mallard embryos are not very sensitive to injected methylmercury; their LC50 was 1.79 ug/g mercury on a wet-weight basis. Other species we categorized as also exhibiting relatively low sensitivity to injected methylmercury (their LC50s were 1 ug/g mercury or higher) were the hooded merganser (Lophodytes cucullatus), lesser scaup (Aythya affinis), Canada goose (Branta canadensis), double-crested cormorant (Phalacrocorax auritus), and laughing gull (Larus atricilla). Species we categorized as having medium sensitivity (their LC50s were greater than 0.25 ug/g mercury but less than 1 ug/g mercury) were the clapper rail (Rallus longirostris), sandhill crane (Grus canadensis), ring-necked pheasant (Phasianus colchicus), chicken (Gallus gallus), common grackle (Quiscalus quiscula), tree swallow (Tachycineta bicolor), herring gull (Larus argentatus), common tern (S terna hirundo), royal tern (Sterna maxima), Caspian tern (Sterna caspia), great egret (Ardea alba), brown pelican (Pelecanus occidentalis), and anhinga (Anhinga anhinga). Species we categorized as exhibiting high sensitivity (their LC50s were less than 0.25 ug/g mercury) were the American kestrel (Falco sparverius), osprey (Pandion haliaetus), white ibis (Eudocimus albus), snowy egret (Egretta thula), and tri-colored heron (Egretta tricolor). For mallards, chickens, and ring-necked pheasants (all species for which we could compare the toxicity of our

  14. Species differences in the sensitivity of avian embryos to methylmercury.

    PubMed

    Heinz, Gary H; Hoffman, David J; Klimstra, Jon D; Stebbins, Katherine R; Kondrad, Shannon L; Erwin, Carol A

    2009-01-01

    We injected doses of methylmercury into the air cells of eggs of 26 species of birds and examined the dose-response curves of embryo survival. For 23 species we had adequate data to calculate the median lethal concentration (LC(50)). Based on the dose-response curves and LC(50)s, we ranked species according to their sensitivity to injected methylmercury. Although the previously published embryotoxic threshold of mercury in game farm mallards (Anas platyrhynchos) has been used as a default value to protect wild species of birds, we found that, relative to other species, mallard embryos are not very sensitive to injected methylmercury; their LC(50 )was 1.79 microg/g mercury on a wet-weight basis. Other species we categorized as also exhibiting relatively low sensitivity to injected methylmercury (their LC(50)s were 1 microg/g mercury or higher) were the hooded merganser (Lophodytes cucullatus), lesser scaup (Aythya affinis), Canada goose (Branta canadensis), double-crested cormorant (Phalacrocorax auritus), and laughing gull (Larus atricilla). Species we categorized as having medium sensitivity (their LC(50)s were greater than 0.25 microg/g mercury but less than 1 microg/g mercury) were the clapper rail (Rallus longirostris), sandhill crane (Grus canadensis), ring-necked pheasant (Phasianus colchicus), chicken (Gallus gallus), common grackle (Quiscalus quiscula), tree swallow (Tachycineta bicolor), herring gull (Larus argentatus), common tern (Sterna hirundo), royal tern (Sterna maxima), Caspian tern (Sterna caspia), great egret (Ardea alba), brown pelican (Pelecanus occidentalis), and anhinga (Anhinga anhinga). Species we categorized as exhibiting high sensitivity (their LC(50)s were less than 0.25 microg/g mercury) were the American kestrel (Falco sparverius), osprey (Pandion haliaetus), white ibis (Eudocimus albus), snowy egret (Egretta thula), and tri-colored heron (Egretta tricolor). For mallards, chickens, and ring-necked pheasants (all species for which we

  15. Polybrominated Diphenyl Ethers (PBDEs) in paired human hair and serum from e-waste recycling workers: source apportionment of hair PBDEs and relationship between hair and serum.

    PubMed

    Zheng, Jing; Chen, Ke-Hui; Luo, Xiao-Jun; Yan, Xiao; He, Chun-Tao; Yu, Yun-Jiang; Hu, Guo-Cheng; Peng, Xiao-Wu; Ren, Ming-Zhong; Yang, Zhong-Yi; Mai, Bi-Xian

    2014-01-01

    Human hair has been widely used as a bioindicator for human persistent organic pollutants (POPs) exposure, but studies on the sources of hair POPs and the relationship between hair and body burden are limited. This study analyzed the possible source apportionment of hair PBDEs and examined the relationship between PBDE concentrations in paired hair and serum from e-waste recycling workers. Using the ratio of BDE 99/47 and BDE 209/207 as indices, we calculated that only 15% of the highly brominated congeners (nona- and deca-BDE congeners) comes from exogenous (external) exposure for both female and male hair, but an average of 64% and 55% of the lower-brominated congeners (tetra- to penta-BDE congeners) come from exogenous exposure for female and male hair, respectively. The higher contribution of exogenous exposure for less-brominated congeners could be related to their relatively lower log KOW and higher volatility than higher-brominated congeners, which make them more readily to evaporate from dust and then to be adsorbed on hair. Higher hair PBDE levels and higher exogenous exposure of less-brominated congeners in females than in males can be attributed to a longer exogenous exposure time for females than males. Significant positive relationships were found in tri- to hepta-BDE congeners (BDE 28, 47, 66, 85, 100, 153, 154, and 183) (R = 0.36-0.55, p < 0.05) between hair and serum, but this relationship was not found for octa- to deca-BDE. Difference in the half-lives between highly brominated congeners and less-brominated congeners could be a reason. This result also implied that we should treat the results of correlation analyses between hair and other organs cautiously. PMID:24320081

  16. Excessive or unwanted hair in women

    MedlinePlus

    Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... much of this hormone, you may have unwanted hair growth. In most cases, the exact cause is ...

  17. Aging changes in hair and nails

    MedlinePlus

    ... of aging. Hair color is due to a pigment called melanin , which hair follicles produce. Follicles are ... slows. Hair strands become smaller and have less pigment. So the thick, coarse hair of a young ...

  18. Neurodevelopmental Effects of Maternal Nutritional Status and Exposure to Methylmercury from Eating Fish during Pregnancy

    PubMed Central

    Davidson, Philip W.; Strain, J.J.; Myers, Gary J.; Thurston, Sally W.; Bonham, Maxine P.; Shamlaye, Conrad F.; Stokes-Riner, Abbie; Wallace, Julie M.W.; Robson, Paula J.; Duffy, Emeir M.; Georger, Lesley A.; Sloane-Reeves, Jean; Cernichiari, Elsa; Canfield, Richard L.; Cox, Christopher; Huang, Li Shan; Janciuras, Joanne; Clarkson, Thomas W.

    2008-01-01

    Fish contain nutrients that promote optimal brain growth and development but also contain methylmercury (MeHg) that can have toxic effects. The present study tested the hypothesis that the intake of selected nutrients in fish or measures of maternal nutritional status may represent important confounders when estimating the effects of prenatal methylmercury exposure on child development. The study took place in the Republic of Seychelles, an Indian Ocean archipelago where fish consumption is high. A longitudinal cohort study design was used. A total of 300 mothers were enrolled early in pregnancy. Nutrients considered to be important for brain development were measured during pregnancy along with prenatal MeHg exposure. The children were evaluated periodically to age 30 months. There were 229 children with complete outcome and covariate data for analysis. The primary endpoint was the Bayley Scales of Infant Development-II (BSID-II), administered at 9 and 30 months of age. Combinations of four secondary measures of infant cognition and memory were also given at 5, 9 and 25 months. Cohort mothers consumed an average of 537 gm of fish (9 meals containing fish) per week. The average prenatal MeHg exposure was 5.9 ppm in maternal hair. The primary analysis examined the associations between MeHg, maternal nutritional measures and children’s scores on the BSID-II and showed an adverse association between MeHg and the mean Psychomotor Developmental Index (PDI) score at 30 months. Secondary analyses of the association between the PDI and only MeHg alone or nutritional factors alone showed only a borderline significant association between MeHg and the PDI at 30 months and no associations with nutritional factors. One experimental measure at 5 months of age was positively associated with iodine status, but not prenatal MeHg exposure. These findings suggest a possible confounding role of maternal nutrition in studies examining associations between prenatal MeHg exposures and

  19. In situ production of methylmercury within a stream channel in northern California.

    PubMed

    Tsui, Martin Tsz Ki; Finlay, Jacques C; Balogh, Steven J; Nollet, Yabing H

    2010-09-15

    Natural stream ecosystems throughout the world are contaminated by methylmercury, a highly toxic compound that bioaccumulates and biomagnifies in aquatic food webs. Wetlands are widely recognized as hotspots for the production of methylmercury and are often assumed to be the main sources of this neurotoxin in downstream ecosystems. However, many streams lacking wetlands in their drainage basins (e.g., montane and semiarid regions in the western United States) have significant methylmercury contamination, and the sources of methylmercury in these streams remain largely unknown. In this study, we observed substantial production of methylmercury within a highly productive stream channel in northern California (South Fork Eel River) within a drainage basin lacking wetlands. We found that in situ methylmercury production is positively related to phosphorus removal and water temperature within the stream channel, supporting hypothesized biological mediation of in situ mercury transformation. Moreover, our data suggest that epiphytic microbial communities on a dominant filamentous alga (Cladophora glomerata) could play a role in in situ methylmercury production. Because peak in situ methylmercury production coincides with the period of the highest biological productivity during summer baseflow, methylmercury produced internally may be efficiently routed into local stream food webs. Our study provides strong evidence that stream channels, especially those associated with high primary productivity, can be important for regulating the bioavailability and toxicity of this global contaminant. PMID:20715863

  20. [Neutron activation analysis of human hair--multivariate analysis of factors influencing on trace element contents in hair-- (author's transl)].

    PubMed

    Imahori, A; Fukushima, I

    1980-06-01

    As a part of IAEA research project, "Activation analysis of hair as an indicator of contamination of man by environmental trace element pollutants", a survey was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo Metropolitan areas, by applying instrumental neutron activation analysis. A total of 202 scalp hair samples were collected from the inhabitants classified by sex and five age classes. Irradiation was made in the Rikkyo University 100 kW TRIGA MARK-II reactor. Using several combinations of irradiation time, cooling time and counting time, forty elements were determined. The relationship between several trace element contents in hair and such factors as sex, age class, hair treatment, smoking habit and dental treatment, was analyzed by using the method of multiple regression. It was shown that (1) Hair treatment had a predominant effect on the contents of bromine, magnesium and calcium in hair, (2) Aging and smoking contributed increasing mercury content in hair, and hair treatment acted reversely. PMID:7208973

  1. Decoction and Fermentation of Selected Medicinal Herbs Promote Hair Regrowth by Inducing Hair Follicle Growth in Conjunction with Wnts Signaling.

    PubMed

    Jang, Su Kil; Kim, Seung Tae; Lee, Do Ik; Park, Jun Sub; Jo, Bo Ram; Park, Jung Youl; Heo, Jong; Joo, Seong Soo

    2016-01-01

    It is well recognized that regulating the hair follicle cycle in association with Wnt signaling is one of the most interesting targets for promoting hair regrowth. In this study, we examined whether selected herbal medicines processed by decoction and fermentation promote hair growth by upregulating the number and size of hair follicles and Wnt signaling, including activation of β-catenin and Akt in telogen-synchronized C57BL/6N mice. The results revealed that the fermented extract after decoction (FDE) more effectively promoted hair growth than that of a nonfermented extract (DE). Notably, FDE effectively enhanced formation of hair follicles with clearer differentiation between the inner and outer root sheath, which is observed during the anagen phase. Mechanistic evidence was found for increased β-catenin and Akt phosphorylation levels in dorsal skin tissue along with elevated expression of hair regrowth-related genes, such as Wnt3/10a/10b, Lef1, and fibroblast growth factor 7. In conclusion, our findings suggest that FDE plays an important role in regulating the hair cycle by increasing expression of hair regrowth-related genes and activating downstream Wnt signaling targets. PMID:27110266

  2. Decoction and Fermentation of Selected Medicinal Herbs Promote Hair Regrowth by Inducing Hair Follicle Growth in Conjunction with Wnts Signaling

    PubMed Central

    Jang, Su Kil; Kim, Seung Tae; Lee, Do Ik; Park, Jun Sub; Jo, Bo Ram; Park, Jung Youl; Heo, Jong; Joo, Seong Soo

    2016-01-01

    It is well recognized that regulating the hair follicle cycle in association with Wnt signaling is one of the most interesting targets for promoting hair regrowth. In this study, we examined whether selected herbal medicines processed by decoction and fermentation promote hair growth by upregulating the number and size of hair follicles and Wnt signaling, including activation of β-catenin and Akt in telogen-synchronized C57BL/6N mice. The results revealed that the fermented extract after decoction (FDE) more effectively promoted hair growth than that of a nonfermented extract (DE). Notably, FDE effectively enhanced formation of hair follicles with clearer differentiation between the inner and outer root sheath, which is observed during the anagen phase. Mechanistic evidence was found for increased β-catenin and Akt phosphorylation levels in dorsal skin tissue along with elevated expression of hair regrowth-related genes, such as Wnt3/10a/10b, Lef1, and fibroblast growth factor 7. In conclusion, our findings suggest that FDE plays an important role in regulating the hair cycle by increasing expression of hair regrowth-related genes and activating downstream Wnt signaling targets. PMID:27110266

  3. The biology of hair diversity.

    PubMed

    Westgate, Gillian E; Botchkareva, Natalia V; Tobin, Desmond J

    2013-08-01

    Hair diversity, its style, colour, shape and growth pattern is one of our most defining characteristics. The natural versus temporary style is influenced by what happens to our hair during our lifetime, such as genetic hair loss, sudden hair shedding, greying and pathological hair loss in the various forms of alopecia because of genetics, illness or medication. Despite the size and global value of the hair care market, our knowledge of what controls the innate and within-lifetime characteristics of hair diversity remains poorly understood. In the last decade, drivers of knowledge have moved into the arena of genetics where hair traits are obvious and measurable and genetic polymorphisms are being found that raise valuable questions about the biology of hair growth. The recent discovery that the gene for trichohyalin contributes to hair shape comes as no surprise to the hair biologists who have believed for 100 years that hair shape is linked to the structure and function of the inner root sheath. Further conundrums awaiting elucidation include the polymorphisms in the androgen receptor (AR) described in male pattern alopecia whose location on the X chromosome places this genetic contributor into the female line. The genetics of female hair loss is less clear with polymorphisms in the AR not associated with female pattern hair loss. Lifestyle choices are also implicated in hair diversity. Greying, which also has a strong genetic component, is often suggested to have a lifestyle (stress) influence and hair follicle melanocytes show declining antioxidant protection with age and lowered resistance to stress. It is likely that hair research will undergo a renaissance on the back of the rising information from genetic studies as well as the latest contributions from the field of epigenetics. PMID:23363384

  4. Dermatotoxicologic clinical solutions: hair dying in hair dye allergic patients?

    PubMed

    Edwards, Ashley; Coman, Garrett; Blickenstaff, Nicholas; Maibach, Howard

    2015-03-01

    This article describes how to identify allergic contact dermatitis resulting from hair dye, and outlines interventions and prevention principles for those who wish to continue dyeing their hair despite being allergic. Hair dye chemicals thought to be the most frequent sensitizers are discussed with instructions for health care providers on how to counsel patients about techniques to minimize exposure to allergenic substances. This framework should allow many patients to continue dyeing their hair without experiencing adverse side effects. PMID:24754409

  5. Moss hair water transport

    NASA Astrophysics Data System (ADS)

    Pan, Zhao; Wu, Nan; Hurd, Randy; Thomson, Scott; Pitt, William; Truscott, Tadd

    2013-11-01

    We present an investigation of water transportation on a moss (Syntrichia caninervis) indigenous to temperate deserts. The moss typically appears to be in a dry, brown state, but is rehydrated by water during the wet season, making the desert green. Small hairs (500-2000 μm in length, and 40 μm in diameter, d) growing out from the tip of the moss leaves transport water back to the leaves. Through high speed observations and mathematical modeling it appears that this transportation is driven by two different mechanisms. 1) Droplet transport is achieved in three ways: i) A large (10d) droplet attached between two intersecting fibers will move toward the bases of the leaves by the changing angle between the two hairs. ii) The shape of the moss hair is conical, thicker at the base, producing a gradient that moves fluid (5d) toward the leaf similar to cactus spines. iii) We also observe that in some cases a Plateau-Rayleigh instability trigger a series of droplets moving toward the base. 2) Micro-grooves on the moss hair transport a film of water along the moss hair when larger droplets are not available. These various water transportation strategies combine to help the moss to survive in the desert and provide valuable insight.

  6. Evaluation of hair humidity resistance/moisturization from hair elasticity.

    PubMed

    Gao, Timothy

    2007-01-01

    Average water regain and hair elasticity (Young's modulus) of virgin dark brown and bleached hair fibers under different relative humidity (RH) were determined. It is observed that hair water regain increases linearly with an increase in RH in the range of 40-85%; and the remaining percent of hair elasticity decreases linearly with an increase in RH in the range of 50-80%. Therefore, measurements of average hair elasticity at 50% and 80% RH, respectively, under various equilibrium times before and after cosmetic treatments can be used to evaluate effects of cosmetic treatments on water adsorption behavior of hair-improvement in hair humidity resistance or enhancement in hair moisture uptake. A Hair Humidity Resistance Factor (H(2)RF) has been defined. If R(2)HF > 1, the product improves hair humidity resistance-anti-frizz; if R(2)HF < 1, the product enhances hair water adsorption; when R(2)HF approximately 1, the product has no significant effect on hair water adsorption behavior. This method was applied to evaluate anti-frizz performance of several shampoo formulations containing Polyquaternium-10, or Polyquaternium-70, or Polyquaternium-67, or Guar Hydroxypropyltrimonium Chloride. It was found PQ-70 shampoo showed the highest H(2)RF value and the best anti-frizz performance among these tested shampoos. The results were consistent with those obtained from Image Analysis. PMID:17728940

  7. Today's Hair Style Could Cause Tomorrow's Hair Loss

    MedlinePlus

    ... https://medlineplus.gov/news/fullstory_158581.html Today's Hair Style Could Cause Tomorrow's Hair Loss Black women who prefer scalp-pulling hairdos ... News) -- Black women who like to wear their hair pulled back tightly may be increasing their risk ...

  8. Today's Hair Style Could Cause Tomorrow's Hair Loss

    MedlinePlus

    ... nih.gov/medlineplus/news/fullstory_158581.html Today's Hair Style Could Cause Tomorrow's Hair Loss Black women who prefer scalp-pulling hairdos ... News) -- Black women who like to wear their hair pulled back tightly may be increasing their risk ...

  9. Causes of hair loss and the developments in hair rejuvenation.

    PubMed

    Rushton, D H; Norris, M J; Dover, R; Busuttil, Nina

    2002-02-01

    Hair is considered to be a major component of an individual's general appearance. The psychological impact of hair loss results in a measurably detrimental change in self-esteem and is associated with images of reduced worth. It is not surprising that both men and women find hair loss a stressful experience. Genetic hair loss is the major problem affecting men and by the age of 50, up to 50% will be affected. Initial attempts to regenerate the lost hair have centred on applying a topical solution of between 2% to 5% minoxidil; however, the results proved disappointing. Recently, finasteride, a type II 5alpha reductase inhibitor has been found to regrow a noticeable amount of hair in about 40% of balding men. Further developments in treatments have lead to the use of a dual type I and type II inhibitor where 90% of those treated regrow a noticeable amount of hair. In women the major cause of hair loss before the age of 50 is nutritional, with 30% affected. Increased and persistent hair shedding (chronic telogen effluvium) and reduced hair volume are the principle changes occurring. The main cause appears to be depleted iron stores, compromised by a suboptimal intake of the essential amino acid l-lysine. Correction of these imbalances stops the excessive hair loss and returns the hair back to its former glory. However, it can take many months to redress the situation. PMID:18498491

  10. Neurotoxic actions of methylmercury on the primate visual system

    SciTech Connect

    Merigan, W.H.; Maurissen, J.P.J.; Weiss, B.; Eskin, T.; Lapham, L.W.

    1983-01-01

    Visual system consequences of exposure to methylmercury were studied in six adult, macaque monkeys. Visual field measures, visual thresholds, and morphological examination were used to determine the nature and possible reversibility of alterations in vision. Visual field constriction (especially in the inferior-nasal field) was an early and apparently reversible indicator of methylmercury intoxication. Such a field loss was found in the absence of either visual threeshold changes or morphologic alterations in visual cortex. More severe poisoning resulted in persistent field constriction, disruption of visual thresholds, and death. A single monkey showed a permanent, bilateral concentric constriction of visual fields. The locus of visual cortex pathology in this monkey corresponded to the projection of the peripheral visual field.

  11. FUNCTIONAL CONSEQUENCES OF PRENATAL METHYLMERCURY EXPOSURE: EFFECTS ON RENAL AND HEPATIC RESPONSES TO TROPHIC STIMULI AND ON RENAL EXCRETORY MECHANISMS

    EPA Science Inventory

    The effects of prenatal exposure to methylmercury on the functional development of renal and hepatic response systems was examined in the developing rat. Methylmercury produced an elevation of basal activity of renal ornithine decarboxylase (ODC, an enzyme involved in regulation ...

  12. Comparison of damage to human hair fibers caused by monoethanolamine- and ammonia-based hair colorants.

    PubMed

    Bailey, Aaron D; Zhang, Guiru; Murphy, Bryan P

    2014-01-01

    The number of Level 3 hair color products that substitute 2-aminoethanol [monoethanolamine (MEA)] for ammonia is increasing. There is some anecdotal evidence that higher levels of MEA can be more damaging to hair and more irritating than a corresponding equivalent level of the typical alkalizer, ammonia (in the form of ammonium hydroxide). Our interest was to understand in more quantitative terms the relative hair damage from the two alkalizers, particularly at the upper limits of MEA on-head use. Limiting investigations of oxidative hair damage to increases in cysteic acid content (from cystine oxidation) can underreport the extent of total damage. Hence, we complemented Fourier transform infrared spectroscopy (FTIR) cysteic acid level measurement with scanning electron microscopy (SEM) photomicrographs to visualize cuticle damage, and protein loss to understand not only the oxidative damage but also the damage caused by other damage pathways, e.g., reaction of the more nucleophilic (than ammonia) MEA with hair protein. In fact, all methods show an increase in damage from MEA-based formulations, up to 85% versus ammonia in the most extreme case. Hence, if the odor of ammonia is a concern, a better approach may be to minimize the volatility of ammonia in specific chassis rather than replacing it with high levels of a potentially more damaging alkalizer such as MEA. PMID:24602818

  13. Effects of Shampoo and Water Washing on Hair Cortisol Concentrations

    PubMed Central

    Hamel, Amanda F.; Meyer, Jerrold S.; Henchey, Elizabeth; Dettmer, Amanda M.; Suomi, Stephen J.; Novak, Melinda A.

    2010-01-01

    Background Measurement of cortisol in hair is an emerging biomarker for chronic stress in human and nonhuman primates. Currently unknown, however, is the extent of potential cortisol loss from hair that has been repeatedly exposed to shampoo and/or water. Methods Pooled hair samples from 20 rhesus monkeys were subjected to five treatment conditions: 10, 20, or 30 shampoo washes, 20 water-only washes, or a no-wash control. For each wash, hair was exposed to a dilute shampoo solution or tap water for 45 s, rinsed 4 times with tap water, and rapidly dried. Samples were then processed for cortisol extraction and analysis using previously published methods. Results Hair cortisol levels were significantly reduced by washing, with an inverse relationship between number of shampoo washes and the cortisol concentration. This effect was mainly due to water exposure, as cortisol levels following 20 water-only washes were similar to those following 20 shampoo treatments. Conclusions Repeated exposure to water with or without shampoo appears to leach cortisol from hair, yielding values that underestimate the amount of chronic hormone deposition within the shaft. Collecting samples proximal to the scalp and obtaining hair washing frequency data may be valuable when conducting human hair cortisol studies. PMID:21034727

  14. Elevated prenatal methylmercury exposure in Nigeria: evidence from maternal and cord blood.

    PubMed

    Obi, Ejeatuluchukwu; Okafor, Charles; Igwebe, Anthony; Ebenebe, Joy; Afonne, Onyenmechi Johnson; Ifediata, Francis; Orisakwe, Orish Ebere; Nriagu, Jerome O; Basu, Niladri

    2015-01-01

    Methylmercury is a neurodevelopmental toxicant that is globally distributed though little is known about prenatal exposures in sub-Saharan Africa. The objective of the current study was to measure total mercury levels in cord blood and maternal blood from 95 mother-newborn pairs recruited from hospitals in Nnewi, Nigeria. The secondary aims of the study were to explore if demographic and dietary factors were associated with blood mercury levels, and to explore if mercury levels were associated with any self-reported health outcome and childbirth outcome. Maternal blood mercury levels averaged 3.6 μg L(-1) and ranged from 1.1 μg L(-1) to 9.5 μg L(-1). Cord blood mercury averaged 5.1 μg L(-1) and ranged from 1.2 μg L(-1) to 10.6 μg L(-1). The mean ratio of mercury in paired cord blood to maternal blood was 1.5 and it ranged from 0.4 to 3.2. Mercury in maternal and cord blood were significantly correlated (r=0.471). More than one-third of mothers reported eating fish at least once per day, and a weak (p=0.08) fish consumption-related increase in blood mercury was found. Cord blood mercury was positively and significantly associated with birth weight and length, and head and chest circumference. Mercury levels in 36% of the participants exceeded the biomonitoring guideline associated with the United States Environmental Protection Agency (U.S. EPA) reference dose for mercury. The study shows that pregnant women and their newborns are exposed to methylmercury and that their exposures are higher compared to general populations sampled from other regions of the world. PMID:25112573

  15. Increased hair testosterone but unaltered hair cortisol in female patients with borderline personality disorder.

    PubMed

    Dettenborn, Lucia; Kirschbaum, Clemens; Gao, Wei; Spitzer, Carsten; Roepke, Stefan; Otte, Christian; Wingenfeld, Katja

    2016-09-01

    A number of studies have reported on dysfunctions in steroid secretion, including altered cortisol and testosterone levels in borderline personality disorder (BDP) patients compared to healthy controls. The present study extends findings from blood and saliva studies to the cumulative measure of hair steroids. We investigated women with BPD (n=18) and age- and education-matched healthy women (n=17). We did not find differences between BPD patients and healthy women (p=0.40) concerning hair cortisol levels but increased hair testosterone levels among BPD patients compared to controls (p=0.03). These results remained when restricting the analyses to unmedicated patients. Our data indicate altered long-term testosterone but not cortisol levels in females with BPD. Future studies should address the possible impact of altered testosterone on medical illness processes including metabolic syndrome in this population. PMID:27290653

  16. Teratogenic efects of injected methylmercury on avian embryos

    USGS Publications Warehouse

    Heinz, Gary H.; Hoffman, David J.; Klimstra, Jon D.; Stebbins, Katherine R.; Kondrad, Shannon L.; Erwin, Carol A.

    2011-01-01

    Controlled laboratory studies with game farm mallards (Anas platyrhynchos) and chickens (Gallus gallus) have demonstrated that methylmercury can cause teratogenic effects in birds, but studies with wild species of birds are lacking. To address this need, doses of methylmercury chloride were injected into the eggs of 25 species of birds, and the dead embryos and hatched chicks were examined for external deformities. When data for controls were summed across all 25 species tested and across all types of deformities, 24 individuals out of a total of 1,533 (a rate of 1.57%) exhibited at least one deformity. In contrast, when data for all of the mercury treatments and all 25 species were summed, 188 deformed individuals out of a total of 2,292 (8.20%) were found. Some deformities, such as lordosis and scoliosis (twisting of the spine), misshapen heads, shortening or twisting of the neck, and deformities of the wings, were seldom observed in controls but occurred in much greater frequency in Hg-treated individuals. Only 0.59% of individual control dead embryos and hatchlings exhibited multiple deformities versus 3.18% for Hg-dosed dead embryos and hatchlings. Methylmercury seems to have a widespread teratogenic potential across many species of birds.

  17. The Growth of Human Hair.

    ERIC Educational Resources Information Center

    Jones, Helen J.

    1984-01-01

    Suggests a simple technique for collecting and observing human hair roots to compare structure, function, and variation. Students extract their own hair samples and view them using a 40-power microscope objective. Differences between active/inactive phases of hair growth are readily observed. (The activity can be adapted for younger students.) (DH)

  18. Future horizons in hair restoration.

    PubMed

    Marshall, Bryan T; Ingraham, Chris A; Wu, Xunwei; Washenik, Ken

    2013-08-01

    This article reviews the history of hair follicle regeneration from follicular fragments and dissociated cells. The challenges of trichogenic in vitro culture and subsequent delivery into the patient are discussed, as well as cosmetic acceptance, recent achievements on regeneration of human hair follicles, and new potential cell sources for hair regeneration. PMID:24017993

  19. Kerr black holes with Proca hair

    NASA Astrophysics Data System (ADS)

    Herdeiro, Carlos; Radu, Eugen; Rúnarsson, Helgi

    2016-08-01

    Bekenstein proved that in Einstein's gravity minimally coupled to one (or many) real, Abelian, Proca field, stationary black holes (BHs) cannot have Proca hair. Dropping Bekenstein's assumption that matter inherits spacetime symmetries, we show this model admits asymptotically flat, stationary, axi-symmetric, regular on and outside an event horizon BHs with Proca hair, for an even number of real (or an arbitrary number of complex) Proca fields. To establish it, we start by showing that a test, complex Proca field can form bound states, with real frequency, around Kerr BHs: stationary Proca clouds. These states exist at the threshold of superradiance. It was conjectured in [1, 2], that the existence of such clouds at the linear level implies the existence of a new family of BH solutions at the nonlinear level. We confirm this expectation and explicitly construct examples of such Kerr BHs with Proca hair (KBHsPH). For a single complex Proca field, these BHs form a countable number of families with three continuous parameters (ADM mass, ADM angular momentum and Noether charge). They branch off from the Kerr solutions that can support stationary Proca clouds and reduce to Proca stars [3] when the horizon size vanishes. We present the domain of existence of one family of KBHsPH, as well as its phase space in terms of ADM quantities. Some physical properties of the solutions are discussed; in particular, and in contrast with Kerr BHs with scalar hair, some spacetime regions can be counter-rotating with respect to the horizon. We further establish a no-Proca-hair theorem for static, spherically symmetric BHs but allowing the complex Proca field to have a harmonic time dependence, which shows BHs with Proca hair in this model require rotation and have no static limit. KBHsPH are also disconnected from Kerr–Newman BHs with a real, massless vector field.

  20. Study of hair shine and hair surface smoothness.

    PubMed

    Gao, Timothy; Pereira, Abel; Zhu, Sam

    2009-01-01

    A new hair visual appearance measurement system called SAMBA from Bossa Nova Technologies (Venice, CA) has been employed to measure effects of cosmetic treatments on hair shine and surface smoothness of different types of hair samples. Experimental procedures for evaluations of shine value and surface cuticle angle of hair samples treated with rinse-off products (shampoo or/and conditioner) have been successfully established and applied. We demonstrated that hair spray and conditioner formulas containing PPG-3 benzyl ether myristate (PBEM) (1) showed great performance on shine enhancement for hairs with light and medium colors. Instrumental measurement of shine values was also conducted to compare different commercial shampoo and conditioner products. This study showed reliable utility of SAMBA system and demonstrated the shine enhancement of PBEM in hair care. PMID:19450419

  1. A study on the concentrations of 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (THCCOOH) in hair root and whole hair.

    PubMed

    Han, Eunyoung; Choi, Hwakyung; Lee, Sangki; Chung, Heesun; Song, Joon Myong

    2011-07-15

    In this study, we investigated the patterns of cannabis users (n=412) according to their sex, age, and the results of urinalysis and hair analysis, and classified the concentrations of THCCOOH in hair into three categories to examine the levels of cannabis use. We also compared the concentrations of THCCOOH in hair root, hair without the hair root and whole hair and examined the relationship among them according to the results of urinalysis. The hair samples were washed, digested with 1ml of 1M NaOH at 85°C for 30min and extracted with 2ml of n-hexane:ethyl acetate (9:1) two times after adding 1ml of 0.1N sodium acetate buffer (pH 4.5) and 200μl of acetic acid. The final mixture was derivatized with 50μl of PFPA and 25μl of PFPOH for 30min at 70°C. The solution was evaporated, and the residue was reconstituted in 40μl of ethyl acetate and transferred to an autosampler vial. One microlitre was injected into the GC/MS/MS-NCI system. The concentrations of THCCOOH ranged from 0.06 to 33.44pg/mg (mean 2.96; median 1.32) in hair from cannabis users who had positive urine results and ranged from 0.05 to 7.24pg/mg (mean 1.35; median 0.37) in hair from cannabis users who had negative urine results. The average concentration of THCCOOH in hair from cannabis users who had positive urine results was higher than that from cannabis users who had negative urine results. Male cannabis users in their forties were predominant. We classified the concentrations of THCCOOH in hair into three groups (low, medium and high), and could use the grouping of THCCOOH in hair as a guide for determining the level of use. The low, medium and high concentration ranges for THCCOOH in hair were 0.05-0.24, 0.25-2.60 and 2.63-33.44pg/mg, respectively. We also investigated 28 hair samples with the root. The highest concentrations of THCCOOH were seen in the hair root from 18 out of the 28 hair samples. The average concentrations of THCCOOH in hair root, hair without hair root and whole hair from

  2. Hair shafts in trichoscopy: clues for diagnosis of hair and scalp diseases.

    PubMed

    Rudnicka, Lidia; Rakowska, Adriana; Kerzeja, Marta; Olszewska, Małgorzata

    2013-10-01

    Trichoscopy (hair and scalp dermoscopy) analyzes the structure and size of growing hair shafts, providing diagnostic clues for inherited and acquired causes of hair loss. Types of hair shaft abnormalities observed include exclamation mark hairs (alopecia areata, trichotillomania, chemotherapy-induced alopecia), Pohl-Pinkus constrictions (alopecia areata, chemotherapy-induced alopecia, blood loss, malnutrition), comma hairs (tinea capitis), corkscrew hairs (tinea capitis), coiled hairs (trichotillomania), flame hairs (trichotillomania), and tulip hairs (in trichotillomania, alopecia areata). Trichoscopy allows differential diagnosis of most genetic hair shaft disorders. This article proposes a classification of hair shaft abnormalities observed by trichoscopy. PMID:24075554

  3. The regulation and plasticity of root hair patterning and morphogenesis.

    PubMed

    Salazar-Henao, Jorge E; Vélez-Bermúdez, Isabel Cristina; Schmidt, Wolfgang

    2016-06-01

    Root hairs are highly specialized cells found in the epidermis of plant roots that play a key role in providing the plant with water and mineral nutrients. Root hairs have been used as a model system for understanding both cell fate determination and the morphogenetic plasticity of cell differentiation. Indeed, many studies have shown that the fate of root epidermal cells, which differentiate into either root hair or non-hair cells, is determined by a complex interplay of intrinsic and extrinsic cues that results in a predictable but highly plastic pattern of epidermal cells that can vary in shape, size and function. Here, we review these studies and discuss recent evidence suggesting that environmental information can be integrated at multiple points in the root hair morphogenetic pathway and affects multifaceted processes at the chromatin, transcriptional and post-transcriptional levels. PMID:27246711

  4. Hippocampal developmental vulnerability to methylmercury extends into prepubescence

    PubMed Central

    Obiorah, Maryann; McCandlish, Elizabeth; Buckley, Brian; DiCicco-Bloom, Emanuel

    2015-01-01

    The developing brain is sensitive to environmental toxicants such as methylmercury (MeHg), to which humans are exposed via contaminated seafood. Prenatal exposure in children is associated with learning, memory and IQ deficits, which can result from hippocampal dysfunction. To explore underlying mechanisms, we have used the postnatal day (P7) rat to model the third trimester of human gestation. We previously showed that a single low exposure (0.6 μg/gbw) that approaches human exposure reduced hippocampal neurogenesis in the dentate gyrus (DG) 24 h later, producing later proliferation and memory deficits in adolescence. Yet, the vulnerable stem cell population and period of developmental vulnerability remain undefined. In this study, we find that P7 exposure of stem cells has long-term consequences for adolescent neurogenesis. It reduced the number of mitotic S-phase cells (BrdU), especially those in the highly proliferative Tbr2+ population, and immature neurons (Doublecortin) in adolescence, suggesting partial depletion of the later stem cell pool. To define developmental vulnerability to MeHg in prepubescent (P14) and adolescent (P21) rats, we examined acute 24 h effects of MeHg exposure on mitosis and apoptosis. We found that low exposure did not adversely impact neurogenesis at either age, but that a higher exposure (5 μg/gbw) at P14 reduced the total number of neural stem cells (Sox2+) by 23% and BrdU+ cells by 26% in the DG hilus, suggesting that vulnerability diminishes with age. To determine whether these effects reflect changes in MeHg transfer across the blood brain barrier (BBB), we assessed Hg content in the hippocampus after peripheral injection and found that similar levels (~800 ng/gm) were obtained at 24 h at both P14 and P21, declining in parallel, suggesting that changes in vulnerability depend more on local tissue and cellular mechanisms. Together, we show that MeHg vulnerability declines with age, and that early exposure impairs later

  5. Determination of methylmercury in marine biota samples: method validation.

    PubMed

    Carrasco, Luis; Vassileva, Emilia

    2014-05-01

    Regulatory authorities are expected to measure concentration of contaminants in foodstuffs, but the simple determination of total amount cannot be sufficient for fully judging its impact on the human health. In particular, the methylation of metals generally increases their toxicity; therefore validated analytical methods producing reliable results for the assessment of methylated species are highly needed. Nowadays, there is no legal limit for methylmercury (MeHg) in food matrices. Hence, no standardized method for the determination of MeHg exists within the international jurisdiction. Contemplating the possibility of a future legislative limit, a method for low level determination of MeHg in marine biota matrixes, based on aqueous-phase ethylation followed by purge and trap and gas chromatography (GC) coupled to pyrolysis-atomic fluorescence spectrometry (Py-AFS) detection, has been developed and validated. Five different extraction procedures, namely acid and alkaline leaching assisted by microwave and conventional oven heating, as well as enzymatic digestion, were evaluated in terms of their efficiency to extract MeHg from Scallop soft tissue IAEA-452 Certified Reference Material. Alkaline extraction with 25% (w/w) KOH in methanol, microwave-assisted extraction (MAE) with 5M HCl and enzymatic digestion with protease XIV yielded the highest extraction recoveries. Standard addition or the introduction of a dilution step were successfully applied to overcome the matrix effects observed when microwave-assisted extraction using 25% (w/w) KOH in methanol or 25% (w/v) aqueous TMAH were used. ISO 17025 and Eurachem guidelines were followed to perform the validation of the methodology. Accordingly, blanks, selectivity, calibration curve, linearity (0.9995), working range (1-800pg), recovery (97%), precision, traceability, limit of detection (0.45pg), limit of quantification (0.85pg) and expanded uncertainty (15.86%, k=2) were assessed with Fish protein Dorm-3 Certified

  6. Methylmercury in biota downstream of Arivaca lake, Arizona, USA.

    PubMed

    Marr, Carrie L H; Robertson, Kathy; Reynolds, Kevin D

    2014-04-01

    Concentrations of total mercury (Hg) and methylmercury (MeHg) were determined in water, sediment, periphyton, spiders, and amphibians from the streams and desert marsh downstream from Arivaca Lake, Arizona, to better understand their distribution and bioaccumulation. Mean concentrations of MeHg in water ranged from 0.09 to 0.93 ng/L, and mean concentrations of total Hg in sediment ranged from 10.4 to 126 μg/kg. Hg and MeHg in water and sediments downstream from Arivaca Lake were low enough that they did not exceed human health or ecological thresholds. Hg and MeHg between sites ranged from 0.11 to 1.90 μg/g Hg and 0.01 to 0.3 μg/g MeHg in periphyton, from 0.09 to 0.25 μg/g Hg and 0.04 to 0.10 μg/g MeHg in spiders, and from 0.15 to 0.38 μg/g Hg and 0.14 to 0.35 μg/g MeHg in adult bullfrogs. No Hg toxicity data exist for periphyton or spiders, but MeHg concentrations in tadpoles (0.04 ± 0.005 μg/g) were lower than those known to cause sublethal effects and subchronic mortality. The mean total Hg concentration in adult bullfrogs in the present study was 0.24 μg/g, which is slightly lower than the mean (0.37 μg/g) from an Hg-contaminated wetland in California. MeHg bioaccumulated at each successive trophic level, and MeHg bioconcentration factors from the Arivaca watershed were similar to those for periphyton but greater than amphibians in other studies. Local resource managers can use these data to determine if water should be released from Arivaca Lake to recharge the aquifer downstream or to decrease Hg methylation in the reservoir. PMID:24468966

  7. Advances in Understanding Hair Growth

    PubMed Central

    Bernard, Bruno A.

    2016-01-01

    In this short review, I introduce an integrated vision of human hair follicle behavior and describe opposing influences that control hair follicle homeostasis, from morphogenesis to hair cycling. The interdependence and complementary roles of these influences allow us to propose that the hair follicle is a true paradigm of a “Yin Yang” type, that is a cold/slow-hot/fast duality. Moreover, a new promising field is emerging, suggesting that glycans are key elements of hair follicle growth control. PMID:26918186

  8. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration.

    PubMed

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang; Li, Ji

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  9. Mitochondrial aerobic respiration is activated during hair follicle stem cell differentiation, and its dysfunction retards hair regeneration

    PubMed Central

    Tang, Yan; Luo, Binping; Deng, Zhili; Wang, Ben; Liu, Fangfen; Li, Jinmao; Shi, Wei; Xie, Hongfu; Hu, Xingwang

    2016-01-01

    Background. Emerging research revealed the essential role of mitochondria in regulating stem/progenitor cell differentiation of neural progenitor cells, mesenchymal stem cells and other stem cells through reactive oxygen species (ROS), Notch or other signaling pathway. Inhibition of mitochondrial protein synthesis results in hair loss upon injury. However, alteration of mitochondrial morphology and metabolic function during hair follicle stem cells (HFSCs) differentiation and how they affect hair regeneration has not been elaborated upon. Methods. We compared the difference in mitochondrial morphology and activity between telogen bulge cells and anagen matrix cells. Expression levels of mitochondrial ROS and superoxide dismutase 2 (SOD2) were measured to evaluate redox balance. In addition, the level of pyruvate dehydrogenase kinase (PDK) and pyruvate dehydrogenase (PDH) were estimated to present the change in energetic metabolism during differentiation. To explore the effect of the mitochondrial metabolism on regulating hair regeneration, hair growth was observed after application of a mitochondrial respiratory inhibitor upon hair plucking. Results. During HFSCs differentiation, mitochondria became elongated with more abundant organized cristae and showed higher activity in differentiated cells. SOD2 was enhanced for redox balance with relatively stable ROS levels in differentiated cells. PDK increased in HFSCs while differentiated cells showed enhanced PDH, indicating that respiration switched from glycolysis to oxidative phosphorylation during differentiation. Inhibiting mitochondrial respiration in differentiated hair follicle cells upon hair plucking repressed hair regeneration in vivo. Conclusions. Upon HFSCs differentiation, mitochondria are elongated with more abundant cristae and show higher activity, accompanying with activated aerobic respiration in differentiated cells for higher energy supply. Also, dysfunction of mitochondrial respiration delays hair

  10. Hair dye poisoning

    MedlinePlus

    ... temporary dyes are: Arsenic Bismuth Denatured alcohol Lead ( lead poisoning ) Mercury Pyrogallol Silver Hair dyes may contain other ... infection. Continued exposure to lead or mercury can lead to permanent brain and nervous system damage. Alternative ... References Lee DC. Hydrocarbons. In: Marx JA, Hockberger ...

  11. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    PubMed

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production. PMID:26499883

  12. Buprenorphine and norbuprenorphine findings in hair during constant maintenance dosage.

    PubMed

    Skopp, Gisela; Kniest, Anja; Haisser, Joerg; Mann, Karl; Hermann, Derik

    2011-03-01

    It is still a matter of debate whether a positive correlation between the dose and the amount of drug in the hair exists. Drugs such as buprenorphine (BUP) used under controlled conditions present an opportunity to prove a possible relationship. Due to discrepant findings of BUP/norbuprenorphine (NBUP) ratios in hair, in vitro degradation of both analytes in diluted acid was also investigated. The levels of BUP and NBUP in proximal hair sections from 18 subjects participating in a maintenance program were determined by liquid chromatography/tandem mass spectrometry following incubation with methanol and subsequent liquid/liquid extraction. BUP and NBUP were incubated in diluted hydrochloric acid at 60°C for up to 24 h. The alleged rearrangement products were simultaneously monitored. All hair samples tested positive for BUP (lower limit of detection-0.238 ng/mg hair) and NBUP (0.043-0.961 ng/mg hair). The concentration of NBUP in hair was consistently higher than that of BUP except for a single specimen. Degradation of BUP and NBUP was dependent on time; hydrolysis of NBUP occurred faster than that of BUP. The concentration of BUP and NBUP will be underestimated if analytes are recovered by acidic procedures. NBUP should be monitored in hair samples besides BUP for the sum of both BUP and NBUP may provide an estimate of BUP exposure following long-term administration of the drug. PMID:21301858

  13. Sulfur and Methylmercury in the Florida Everglades - the Biogeochemical Connection

    NASA Astrophysics Data System (ADS)

    Orem, W. H.; Gilmour, C. C.; Krabbenhoft, D. P.; Aiken, G.

    2011-12-01

    Methylmercury (MeHg) is a serious environmental problem in aquatic ecosystems worldwide because of its toxicity and tendency to bioaccumulate. The Everglades receives some of the highest levels of atmospheric mercury deposition and has some of the highest levels of MeHg in fish in the USA, posing a threat to pisciverous wildlife and people through fish consumption. USGS studies show that a combination of biogeochemical factors make the Everglades especially susceptible to MeHg production and bioaccumulation: (1) vast wetland area with anoxic soils supporting anaerobic microbial activity, (2) high rates of atmospheric mercury deposition, (3) high levels of dissolved organic carbon (DOC) that complexes and stabilizes mercury in solution for transport to sites of methylation, and (4) high sulfate loading in surface water that drives microbial sulfate reduction and mercury methylation. The high levels of sulfate in the Everglades represent an unnatural condition. Background sulfate levels are estimated to be <1 mg/L, but about 60% of the Everglades has surface water sulfate concentrations exceeding background. Highly sulfate-enriched marshes in the northern Everglades have average sulfate levels of 60 mg/L. Sulfate loading to the Everglades is principally a result of land and water management in south Florida. The highest concentrations of sulfate, averaging 60-70 mg/L, are in canal water in the Everglades Agricultural Area (EAA). Geochemical data and a preliminary sulfur mass balance for the EAA are consistent with sulfur currently used in agriculture, and sulfur released by oxidation of organic EAA soils (including legacy agricultural applications and natural sulfur) as the primary sources of sulfate enrichment to the canals and ecosystem. Sulfate loading increases microbial sulfate reduction and MeHg production in soils. The relationship between sulfate loading and MeHg production, however, is complex. Sulfate levels up to about 20-30 mg/L increase mercury

  14. Effects of environmental temperatures on the toxicity of methylmercury in rats

    SciTech Connect

    Yamaguchi, S.; Shimojo, N.; Sano, K.; Kano, K.; Hirota, Y.; Saisho, A.

    1984-05-01

    The study was designed to examine the influence of environmental temperatures on subacute (5 mg/kg/3 days) methylmercury toxicity in rats by observations of mortality, manifestation of the hindleg-crossing phenomenon, and measurement of total and methylmercury in tissue samples.

  15. A COMBINED PHYSIOLOGICAL AND BIOENERGETICS-BASED MODEL FOR METHYLMERCURY IN FEMALE AMERICAN KESTRELS

    EPA Science Inventory

    The results of this combined dose-response and modeling effort will be used to improve effects characterizations for methylmercury in avian wildlife. This information will reduce uncertainty in risk assessments for methylmercury in the environment and contribute to the developme...

  16. Pharmacologic interventions in aging hair

    PubMed Central

    Trüeb, Ralph M

    2006-01-01

    The appearance of hair plays an important role in people’s overall physical appearance and self-perception. With today’s increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation. PMID:18044109

  17. Pharmacologic interventions in aging hair.

    PubMed

    Trüeb, Ralph M

    2006-01-01

    The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation. PMID:18044109

  18. Female pattern hair loss.

    PubMed

    Singal, Archana; Sonthalia, Sidharth; Verma, Prashant

    2013-01-01

    Female pattern hair loss (FPHL) is a common cause of hair loss in women characterized by diffuse reduction in hair density over the crown and frontal scalp with retention of the frontal hairline. Its prevalence increases with advancing age and is associated with significant psychological morbidity. The pathophysiology of FPHL is still not completely understood and seems to be multifactorial. Although androgens have been implicated, the involvement of androgen-independent mechanisms is evident from frequent lack of clinical or biochemical markers of hyperandrogenism in affected women. The role of genetic polymorphisms involving the androgen and estrogen receptors is being increasingly recognized in its causation and predicting treatment response to anti-androgens. There are different clinical patterns and classifications of FPHL, knowledge of which facilitates patient management and research. Chronic telogen effluvium remains as the most important differential diagnosis. Thorough history, clinical examination, and evaluation are essential to confirm diagnosis. Patients with clinical signs of androgen excess require assessment of biochemical parameters and imaging studies. It is prudent to screen the patients for metabolic syndrome and cardiovascular risk factors. The treatment comprises medical and/or surgical modalities. Medical treatment should be initiated early as it effectively arrests hair loss progression rather than stimulating regrowth. Minoxidil continues to be the first line therapy whereas anti-androgens form the second line of treatment. The progressive nature of FPHL mandates long-term treatment for sustained effect. Medical therapy may be supplemented with cosmetic concealment in those desirous of greater hair density. Surgery may be worthwhile in some carefully selected patients. PMID:23974580

  19. Patient satisfaction following the use of a hair fiber filler product to temporarily increase the thickness and fullness of thinning hair.

    PubMed

    Pinski, Kevin S

    2014-01-01

    Hair loss can have a negative effect on self-image and self-esteem for both men and women. The results of a recent randomized, placebo-controlled, double-blind study demonstrated the ability of a new oral dietary supplement to increase hair growth in women with thinning hair after 90 days. A companion hair fiber filler product has been designed to be applied to areas of thinning hair to provide the temporary appearance of fuller-looking hair until their own hair is replenished. Forty men and women from a dermatology and cosmetic surgery clinic were asked to use the product and afterward complete quality-of-life, self-assessment, and product satisfaction questionnaires. Mean quality-of-life and self-assessment results were favorable. Hair qualities showing the greatest improvement were scalp coverage and hair fullness. The product satisfaction questionnaire indicated a high level of satisfaction and most patients (35 [88%]) were pleased with the way the product matched their natural hair color. Based on the results reported here, use of the product is likely to increase the quality of life of men and women with thinning hair. PMID:25632645

  20. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    PubMed

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas. PMID:26974480

  1. An assessment of the cord blood:maternal blood methylmercury ratio: implications for risk assessment.

    PubMed Central

    Stern, Alan H; Smith, Andrew E

    2003-01-01

    In the current U.S. Environmental Protection Agency reference dose (RfD) for methylmercury, the one-compartment pharmacokinetic model is used to convert fetal cord blood mercury (Hg) concentration to a maternal intake dose. This requires a ratio relating cord blood Hg concentration to maternal blood Hg concentration. No formal analysis of either the central tendency or variability of this ratio has been done. This variability contributes to the overall variability in the dose estimate. A ratio of 1.0 is implicitly used in the model, but an uncertainty factor adjustment is applied to the central tendency estimate of dose to address variability in that estimate. Thus, incorporation of the cord:maternal ratio and its variability into the estimate of intake dose could result in a significant change in the value of the RfD. We analyzed studies providing data on the cord:maternal blood Hg ratio and conducted a Monte Carlo-based meta-analysis of 10 studies meeting all inclusion criteria to generate a comprehensive estimate of the central tendency and variability of the ratio. This analysis results in a recommended central tendency estimate of 1.7, a coefficient of variation of 0.56, and a 95th percentile of 3.4. By analogy to the impact of the similar hair:blood Hg ratio on the overall variability in the dose estimate, incorporation of the cord:maternal ratio may support a 3-fold uncertainty factor adjustment to the central tendency estimate of dose to account for pharmacokinetic variability. Whether the information generated in this analysis is sufficient to warrant a revision to the RfD will depend on the outcome of a comprehensive reanalysis of the entire one-compartment model. We are currently engaged in such an analysis. PMID:12948885

  2. Simple analysis of total mercury and methylmercury in seafood using heating vaporization atomic absorption spectrometry.

    PubMed

    Yoshimoto, Keisuke; Anh, Hoang Thi Van; Yamamoto, Atsushi; Koriyama, Chihaya; Ishibashi, Yasuhiro; Tabata, Masaaki; Nakano, Atsuhiro; Yamamoto, Megumi

    2016-01-01

    This study aimed to develop a simpler method for determining total mercury (T-Hg) and methylmercury (MeHg) in biological samples by using methyl isobutyl ketone (MIBK) in the degreasing step. The fat in the samples was extracted by MIBK to the upper phase. T-Hg transferred into the water phase. This was followed by the extraction of MeHg from the water phase using HBr, CuCl2 and toluene. The MeHg fraction was reverse-extracted into L-cysteine-sodium acetate solution from toluene. The concentrations of T-Hg and MeHg were determined by heating vaporization atomic absorption spectrometry. Certified reference materials for T-Hg and MeHg in hair and fish were accurately measured using this method. This method was then applied to determine T-Hg and MeHg concentrations in the muscle, liver and gonads of seafood for the risk assessment of MeHg exposure. The mean T-Hg and MeHg concentrations in squid eggs were 0.023 and 0.022 µg/g, and in squid nidamental glands 0.052 and 0.049 µg/g, respectively. The MeHg/T-Hg ratios in the eggs and nidamental glands of squid were 94.4% and 96.5%, respectively. The mean T-Hg and MeHg concentrations in the gonads of sea urchins were 0.043 and 0.001 µg/g, respectively, with a MeHg/T-Hg ratio of 3.5%. We developed an efficient analytical method for T-Hg and MeHg using MIBK in the degreasing step. The new information on MeHg concentration and MeHg/T-Hg ratios in the egg or nidamental glands of squid and gonads of sea urchin will also be useful for risk assessment of mercury in seafood. PMID:27432235

  3. Antagonistic interaction of selenomethionine enantiomers on methylmercury toxicity in the microalgae Chlorella sorokiniana.

    PubMed

    Moreno, Fernando; García-Barrera, Tamara; Gómez-Jacinto, Verónica; Gómez-Ariza, José Luis; Garbayo-Nores, Inés; Vílchez-Lobato, Carlos

    2014-02-01

    The protective effect of selenium against mercury toxicity is well known especially between selenomethionine and methylmercury and it has been studied in several living organisms, however information is lacking about the interaction of these species in Chlorella. Investigation into which chiral form of selenomethionine effectively acts against the toxic effects of methylmercury has not previously been carried out. In the present work, two control cultures and two cultures of C. sorokiniana were grown in standard medium with D,L-SeMet, L-SeMet or D-SeMet. After the experiment was started up MeHg(+) was added periodically to the cultures containing D,L-SeMet, L-SeMet, D-SeMet and to one of the control batches. The results show that both SeMet enantiomers counteract the toxicity of MeHg(+), by markedly increasing the total content of chlorophyll, carotenoids, as well as the dry weight and light dependent oxygen production, compared to the culture which is non pre-treated with SeMet and is only exposed to MeHg(+). The levels of MeHg(+) measured in cells are lower in the cultures pre-treated with SeMet indicating that the passage of MeHg(+) into the cells is negligible when carried out in the presence of SeMet, or that SeMet enhances the release of MeHg(+). On the other hand, L-SeMet is directly involved in the detoxification of MeHg(+), but the involvement of D-SeMet occurs only indirectly since it has been neither identified in the medium nor in C. sorokiniana after supplementation with this enantiomer. It may be that D-SeMet is transformed into SeMeSec and L-SeMet. Moreover, SeMeSec is almost totally released from the cells after 72 hours. No mercury-selenium complex was detected but, since the summation of the different species identified accounted only for 77% of the total selenium and mercury measured directly after sample digestion, it is possible that they are present in the form of an undetected Se-Hg complex. This hypothesis is supported by the decrease of

  4. Differential therapeutic responses of thiol compounds in the reversal of methylmercury inhibited acid phosphatase and cathepsin E in the central nervous system of rat

    SciTech Connect

    Vinay, S.D.; Raghu, K.G.; Sood, P.P.

    1992-07-01

    Though considerable headway has been made in elucidating the effect of methylmercury on the biochemical machinery of nervous system, the studies on the alterations in the levels of acid hydrolases received less attention. Being a lysosomal marker, acid phosphatase is one of the most extensively studies enzymes amongst the acid hydrolases. Its significance in various key physiological as well as pathological processes is well preserved in literature. Cathepsin E, an aspartic proteinase, has been demonstrated in a number of cells and tissues within the human body, rat, E. coli where its role is implicated in a number of important metabolic processes. In the present paper, we report the results of the differential levels of inhibition of these enzymes with methylmercury as well as their differential recoveries with two thiols (N-acetyl-DL-homocysteine thiolactone and glutathione) in various neuroanatomical areas (olfactory bulbs, cerebral hemispheres, cerebellum, medulla oblongata and spinal cord) of rat. 22 refs., 5 figs.

  5. Comparison of ethyl glucuronide in hair with carbohydrate-deficient transferrin in serum as markers of chronic high levels of alcohol consumption.

    PubMed

    Morini, Luca; Politi, Lucia; Acito, Silvia; Groppi, Angelo; Polettini, Aldo

    2009-07-01

    This study was designed with the aim to compare sensitivity and specificity of ethyl glucuronide in hair (HEtG) and carbohydrate-deficient transferrin (CDT) in serum as markers of heavy drinking. Eighty-six volunteers, including teetotalers, social, and heavy drinkers, were interviewed to evaluate their ethanol daily intake (EDI) during the last 2-week and 3-month periods. HEtG determination was performed by a fully validated LC-MS-MS procedure and ranged from

  6. Root hair-specific EXPANSIN A7 is required for root hair elongation in Arabidopsis.

    PubMed

    Lin, Changfa; Choi, Hee-Seung; Cho, Hyung-Taeg

    2011-04-01

    Expansins are non-hydrolytic cell wall-loosening proteins that are involved in the cell wall modifications that underlie many plant developmental processes. Root hair growth requires the accumulation of cell wall materials and dynamic cell wall modification at the tip region. Although several lines of indirect evidence support the idea that expansin-mediated wall modification occurs during root hair growth, the involvement of these proteins remains to be demonstrated in vivo. In this study, we used RNA interference (RNAi) to examine the biological function of Arabidopsis thaliana EXPANSIN A7 (AtEXPA7), which is expressed specifically in the root hair cell. The root hairspecific AtEXPA7 promoter was used to drive RNAi expression, which targeted two independent regions in the AtEXPA7 transcript. Quantitative reverse transcriptase-PCR analyses were used to examine AtEXPA7 transcript levels. In four independent RNAi transformant lines, RNAi expression reduced AtEXPA7 transcript levels by 25-58% compared to controls. Accordingly, the root hairs of RNAi transformant lines were 25-48% shorter than control plants and exhibited a broader range of lengths than the controls. Our results provide in vivo evidence that expansins are required for root hair tip growth. PMID:21359675

  7. Synthesis and characterization of composite polymer, polyethylene glycol grafted flower-like cupric nano oxide for solid phase microextraction of ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair and water samples.

    PubMed

    Sarafraz-Yazdi, Ali; Zendegi-Shiraz, Amene; Es'haghi, Zarrin; Hassanzadeh-Khayyat, Mohammad

    2015-10-30

    In this research, poly (ethylene glycol)-poly (ethylene glycol) grafted flower-like cupric oxidenano particles (PEG-PEG-g-CuO NPs) as a novel fiber coating of solid-phase microextraction (SPME) were synthesized by using sol-gel technology. This fiber was successfully applied to extract and determine the ultra-trace levels of benzene, toluene, ethyl benzene and o-xylene in human hair using head space-solid-phase microextraction (HS-SPME) coupled to gas chromatography-flame ionization detector. Characterization and chemical composition of the nano particle was performed by Fourier transform infrared spectroscopy (FT-IR), energy dispersion spectroscopy (EDS) and back scatter analysis (BSA). These methods confirmed the successful fabrication of PEG-g-CuO NPs. The surface morphology of the fibers were inspected by scanning electron microscopy. The scanning electron microscopy (SEM) revealed many "crack-like" features and highly porous structure on the surface of fiber. The synthesized nanocomposites were used for preconcentration and extraction of benzene, toluene, ethyl benzene and o-xylene (BTEX). The effects of operating parameters such as: desorption temperature and time, extraction temperature, extraction time, stirring speed and salt effect were investigated and optimized. Under the optimal conditions, the method detection limits and the limits of quantification were between 0.00025-50.00000pgmL(-1) and 0.00200-200.00000pgmL(-1), respectively. Linearity was observed over a range 0.00200-200000.00000pgmL(-1). The relative standard deviations for one fiber (repeatability; n=5) were obtained from 3.30 up to 5.01% and between fibers or batch to batch (n=3; reproducibility) in the range of 3.63-6.21%. The developed method was successfully applied to simultaneous determination of BTEX in human hairs, tap water and distillate water. PMID:26411479

  8. Exposure profiles of mercury in human hair at a terai belt of North India.

    PubMed

    Masih, Amit; Taneja, Ajay; Singhvi, Raj

    2016-02-01

    Human hair is frequently used as a bioindicator of mercury exposure. Mercury (Hg) has for centuries been a useful metal in a variety of applications. Unfortunately, this usefulness is counterbalanced by its neurotoxicological health impact. The US Environmental Protection Agency recommends keeping the hair Hg level <1.0 µg/g. Therefore, an investigation has been performed in order to ascertain the hair Hg levels among the people living at the terai belt of North India. Hair samples were collected from 111 individuals and were placed in an identified plastic bag, stapled to prevent the shift of the hair strand. Samples were analyzed by combustion, gold amalgamation, atomic absorption spectrometry (C-GA-AAS). The mean Hg level in hair was 0.28 µg/g for the whole group ranging from 0.0012 to 1.9091 µg/g. The mean hair Hg levels were 0.16 µg/g for men and 0.12 µg/g for women, indicating that men had higher hair Hg levels than women. Total hair Hg was found to be significantly associated with age, gender and fish consumption frequency. 98 % of the total sample had hair Hg concentrations less than 1.0 µg/g, i.e, within safe dose, whereas only 2 % had Hg concentrations greater than 1.0 µg/g, thereby exceeding the safe dose. PMID:25837822

  9. Selective hair therapy: bringing science to the fiction.

    PubMed

    Vogt, Annika; Blume-Peytavi, Ulrike

    2014-02-01

    Investigations on carrier-based drug delivery systems for higher selectivity in hair therapy have clearly evolved from dye release and model studies to highly sophisticated approaches, many of which specifically tackle hair indications and the delivery of hair-relevant molecules. Here, we group recent hair disease-oriented work into efforts towards (i) improved delivery of conventional drugs, (ii) delivery of novel drug classes, for example biomolecules and (iii) targeted delivery on the cellular/molecular level. Considering the solid foundation of experimental work, it does not take a large step outside the current box of thinking to follow the idea of using large carriers (>500 nm, unlikely to penetrate as a whole) for follicular penetration, retention and protection of sensitive compounds. Yet, reports on particles <200 nm being internalized by keratinocytes and dendritic cells at sites of barrier disruption (e.g., hair follicles) combined with recent advances in nanodermatology add interesting new facets to the possibilities carrier technologies could offer, for example, unprecedented levels of selectivity. The authors provide thought-provoking ideas on how smart delivery technologies and advances in our molecular understanding of hair pathophysiology could result in a whole new era of hair therapeutics. As the field still largely remains in preclinical investigation, determined efforts towards production of medical grade material and truly translational work are needed to demonstrate surplus value of carrier systems for clinical applications. PMID:24387677

  10. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  11. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  12. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  13. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  14. 28 CFR 551.4 - Hair length.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service...

  15. Hair Styling Appliances

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Key tool of Redken Laboratories new line of hair styling appliances is an instrument called a thermograph, a heat sensing device originally developed by Hughes Aircraft Co. under U.S. Army and NASA funding. Redken Laboratories bought one of the early models of the Hughes Probeye Thermal Video System or TVS which detects the various degrees of heat emitted by an object and displays the results in color on a TV monitor with colors representing different temperatures detected.

  16. Normal and aging hair biology and structure 'aging and hair'.

    PubMed

    Goodier, Molly; Hordinsky, Maria

    2015-01-01

    Much like an individual's hairstyle, hair fibers along the scalp see a number of changes over the course of one's lifetime. As the decades pass, the shine and volume synonymous with youthful hair may give way to thin, dull, and brittle hair commonly associated with aging. These changes are a result of a compilation of genetic and environmental elements influencing the cells of the hair follicle, specifically the hair follicle stem cells and melanocytes. Telomere shortening, decrease in cell numbers, and particular transcription factors have all been implicated in this process. In turn, these molecular alterations lead to structural modifications of the hair fiber, decrease in melanin production, and lengthening of the telogen phase of the hair cycle. Despite this inevitable progression with aging, there exists an array of treatments such as light therapy, minoxidil, and finasteride which have been designed to mitigate the effects of aging, particularly balding and thinning hair. Although each works through a different mechanism, all aim to maintain or potentially restore the youthful quality of hair. PMID:26370639

  17. Acceptability and validity of hair collection from Latino children to assess exposure to environmental tobacco smoke.

    PubMed

    Woodruff, Susan I; Conway, Terry L; Edwards, Christine C; Hovell, Melbourne F

    2003-06-01

    This study assessed the acceptability of collecting hair from Latino children to measure environmental tobacco smoke (ETS) exposure and examined the concurrent validity between nicotine and cotinine levels in children's hair in relation to adult reports of the children's ETS exposure. Trained Latina lay community health advisors recruited 143 Spanish-speaking Latino adult volunteers and their children. Bilingual-bicultural measurement technicians collected two types of data: (a) the adult's paper-and-pencil report about the child's past-month exposure to cigarettes in the home and car and (b) a sample of the child's hair to be analyzed for nicotine and cotinine. Of the eligible subjects, 8.5% declined to participate because of the hair collection protocol, some citing cultural beliefs. Among participants in the study, few problems arose related to hair collected, probably because of the culturally sensitive approach used during recruitment and measurement. Adults' reports of exposure, hair nicotine, and hair cotinine showed considerable variation and were skewed to the right. Average nicotine levels for these children appeared to be comparable to those reported elsewhere, whereas cotinine levels appeared to be somewhat lower. Hair nicotine was more detectable than hair cotinine and, compared with cotinine, showed a clearer linear relationship with adults' reports. However, associations between adults' reports and both biological measures were modest. Collecting hair samples in the field (i.e., participants' homes) to measure Latino children's ETS exposure is generally acceptable when appropriate methods are used. Hair nicotine may be a more valid and practical biological measure than hair cotinine. Hair sampling may be a potentially useful, noninvasive technique in ETS studies, although the modest associations of constituents in children's hair with adults' reports indicates that each measure provides different information about ETS exposure. PMID:12791534

  18. Brain lesions in mallard ducklings from parents fed methylmercury

    USGS Publications Warehouse

    Heinz, G.H.; Locke, L.N.

    1976-01-01

    Methylmercury dicyandiamide was fed to mallard ducks at 3 ppm mercury. Mercury accumulated in the eggs to an average of 7.18 and 5.46 ppm on a wet-weight basis in 2 successive years. Mercury in the eggs is believed to have caused brain lesions in the hatched ducklings. Lesions included demyelination, neuron shrink-age, necrosis, and hemorrhage in the meninges overlying the cerebellum. Brains of dead ducklings contained an average of 6.17 and 5.19 ppm mercury on a wet-weight basis in 2 successive years.

  19. Female Pattern Hair Loss

    PubMed Central

    Herskovitz, Ingrid; Tosti, Antonella

    2013-01-01

    Context: Female pattern hair loss (FPHL) also known as female androgenetic alopecia is a common condition afflicting millions of women that can be cosmetically disrupting. Prompt diagnosis and treatment are essential for obtaining optimal outcome. This review addresses the clinical presentation of female pattern hair loss, its differential diagnosis and treatment modalities. Evidence Acquisition: A) Diffuse thinning of the crown region with preservation of the frontal hairline (Ludwig’s type) B) The “Christmas tree pattern” where the thinning is wider in the frontal scalp giving the alopecic area a triangular shaped figure resembling a christmas tree. C) Thinning associated with bitemporal recession (Hamilton type). Generally, FPHL is not associated with elevated androgens. Less commonly females with FPHL may have other skin or general signs of hyperandrogenism such as hirsutism, acne, irregular menses, infertility, galactorrhea and insulin resistance. The most common endocrinological abnormality associated with FPHL is polycystic ovarian syndrome (PCOS). Results: The most important diseases to consider in the differential diagnosis of FPHL include Chronic Telogen Effluvium (CTE), Permanent Alopecia after Chemotherapy (PAC), Alopecia Areata Incognito (AAI) and Frontal Fibrosing Alopecia (FFA). This review describes criteria for distinguishing these conditions from FPHL. Conclusions: The only approved treatment for FPHL, which is 2% topical Minoxidil, should be applied at the dosage of 1ml twice day for a minimum period of 12 months. This review will discuss off-label alternative modalities of treatment including 5-alfa reductase inhibitors, antiandrogens, estrogens, prostaglandin analogs, lasers, light treatments and hair transplantation. PMID:24719635

  20. New approach for assessing human perfluoroalkyl exposure via hair.

    PubMed

    Alves, Andreia; Jacobs, Griet; Vanermen, Guido; Covaci, Adrian; Voorspoels, Stefan

    2015-11-01

    In the recent years hair has been increasingly used as alternative matrix in human biomonitoring (HBM) of environmental pollutants. Sampling advantages and time integration of exposure assessment seems the most attractive features of hair matrix. In the current study, a novel miniaturized method was developed and validated for measuring 15 perfluoroalkyl substances (PFAS), including perfluoro n-butanoic acid (PFBA), perfluoro n-pentanoic acid (PFPeA), perfluoro n-hexanoic acid (PFHxA), perfluoro n-heptanoic acid (PFHpA), perfluor n-octanoic acid (PFOA), perfluoro n-nonanoic acid (PFNA), perfluoro tetradecanoic acid (PFTeDA), perfluorobutane sulfonic acid (PFBS), perfluoro pentane sulfonic acid (PFPeS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), perfluorononane sulfonic acid (PFNS), perfluorodecane sulfonic acid (PFDS) and perfluorododecane sulfonic acid (PFDoS) in human hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). After extraction using ethyl acetate, dispersive ENVI-Carb was used for clean-up. Good intra- and inter-day precision for low (LQ 5 ng/g hair) and high spike (HQ 15n g/g) levels were achieved (in general RSD <10%). The accuracy was assessed using recoveries (%), which ranged between 68-118% (LQ) and 70-121% (HQ). The instrumental limit of detection (LODi) and limit of quantification (LOQi) were between 1-4 pg/g hair and 3-13 pg/g hair, respectively. The method limit of quantification (LOQm) ranged between 6 and 301 pg/g hair. The PFAS levels were measured in 30 human hair samples indicating that the levels are low (14-1534 pg/g hair). Some PFAS were not present in any hair sample (e.g. PFHpA, PFTeDA, PFNA, PFPeS, PFHpS, PFOS and PFNS), while other PFAS were frequently detected (PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, PFOS, PFDS and PFDoS) in human hair. Although levels in general were low, there is evidence of higher human exposure to some analytes, such as PFBA

  1. Through form to function: root hair development and nutrient uptake

    NASA Technical Reports Server (NTRS)

    Gilroy, S.; Jones, D. L.

    2000-01-01

    Root hairs project from the surface of the root to aid nutrient and water uptake and to anchor the plant in the soil. Their formation involves the precise control of cell fate and localized cell growth. We are now beginning to unravel the complexities of the molecular interactions that underlie this developmental regulation. In addition, after years of speculation, nutrient transport by root hairs has been demonstrated clearly at the physiological and molecular level, with evidence for root hairs being intense sites of H(+)-ATPase activity and involved in the uptake of Ca(2+), K(+), NH(4)(+), NO(3)(-), Mn(2+), Zn(2+), Cl(-) and H(2)PO(4)(-).

  2. Hair removal on dermoscopy images.

    PubMed

    Maglogiannis, Ilias; Delibasis, Kostantinos

    2015-08-01

    Digital Dermoscopy is a tool commonly used by dermatologists for assisting the diagnosis of skin lesions. The presence of hair in such dermoscopic images frequently occludes significant diagnostic information and reduces their value. In this work we propose algorithms that successfully identify and remove hair from the dermoscopic images. The proposed algorithms consist of two parts; the first deals with the identification of hair, while the second part concerns the image restoration using interpolation. For the evaluation of the algorithms we used ground truth images with synthetic hair and compared the results with the commonly used in the literature DullRazor tool. According to the experimental results the proposed hair removal algorithms can be used successfully in the detection and removal of both dark and light colored hair. PMID:26736913

  3. Repair of traumatized mammalian hair cells via sea anemone repair proteins.

    PubMed

    Tang, Pei-Ciao; Smith, Karen Müller; Watson, Glen M

    2016-08-01

    Mammalian hair cells possess only a limited ability to repair damage after trauma. In contrast, sea anemones show a marked capability to repair damaged hair bundles by means of secreted repair proteins (RPs). Previously, it was found that recovery of traumatized hair cells in blind cavefish was enhanced by anemone-derived RPs; therefore, the ability of anemone RPs to assist recovery of damaged hair cells in mammals was tested here. After a 1 h incubation in RP-enriched culture media, uptake of FM1-43 by experimentally traumatized murine cochlear hair cells was restored to levels comparable to those exhibited by healthy controls. In addition, RP-treated explants had significantly more normally structured hair bundles than time-matched traumatized control explants. Collectively, these results indicate that anemone-derived RPs assist in restoring normal function and structure of experimentally traumatized hair cells of the mouse cochlea. PMID:27489215

  4. Organic components in hair-ice

    NASA Astrophysics Data System (ADS)

    Hofmann, Diana; Steffen, Bernhard; Disko, Ulrich; Wagner, Gerhard; Mätzler, Christian

    2013-04-01

    supra-conducting magnet (LTQ-FT Ultra, ThermoFisher Scientific). This technique is the key technique for the analysis of complex samples due to its outstanding mass resolution (used 400.000 at m/z 400 Da) and mass accuracy (≤ 1 ppm), simultaneously providing molecular level details of thousands of compounds. The characteristics of the FTICR-MS hair-ice spectra with as many as ten or more peaks at each nominal mass are discussed together with highly resolved spectra from water and soil samples different sources, respectively. Complete manual formula assignment for structure elucidation would be extremely time consuming, therefore, we used an automated post processing based on SciLab for exploitation of the data with the aim of an unambiguous assignment of as many peaks as possible. Once the formulae had been assigned, the obtained mass lists were first checked randomly and afterwards transformed into Excel format for further post-processing and description. Most important is the van Krevelen diagram, usually two-dimensional as atomic ratio H/C versus atomic ratio O/C, widely used to classify samples regarding polarity and aromaticity. By comparison with two references (Hockaday 2007, Sleighter 2007), which arranged various biopolymer substance classes in such Van Krevelen plots, lignin could be detected as the main hair-ice component.

  5. ASSOCIATION BETWEEN SHORT STATURE AND HAIR ELEMENTS.

    PubMed

    Tabatadze, T; Zhorzholiani, L; Kherkheulidze, M; Karseladze, R; Ivanashvili, T

    2015-10-01

    Aim - assessment of hair elemental status, determination of elemental imbalances and heavy metal concentration and evaluation its impact on child liner growth. Case-control study involves 112 children less than 5 years old (target group - 54 children with short stature, control - 58 children with normal physical development). Medical history, nutritional status, anthropological parameters were assessed. Patients with genetic and endocrine disorders, family short stature were excluded from the study. Child elemental status was detected in the hair, with roentgen-fluorescence spectrometer method. Statistical analysis was conduced using SPPS19. Assessment of the dietary history does not reveal any significant differences between the groups, the only exception was consumption of fish, that was statistically significantly lower than in control (p<0,05). The study revealed deficiency of some elements in both (study and control) groups, but there were significant difference between the groups: Zn deficiency 90% versus 40% (p<0,05), Ca deficiency 62 and 36 (p<0,05), Cu deficiency 50 and 16 (p<0,05) and Mn deficiency 30 and 6 (p<0,05) accordingly. Level of some elements (K, S, Br, Cl, Co, Ag, V, Ni, Rb, Sr, Ti, Ba, As, Cd, Zr, Sb) have normal values. Some element deficiency (Fe, Mo, Se) was higher in study group but the difference was not significant. The study revealed high level of hair lead in both groups: all patients (100%) of target group have elevated level of hair lead, among them in 35,8% the content of lead was above so-called minimal allowed level (p<5,0 ppm) and in 64,5% the content of lead in the hair was above so-called maximal allowed level (p≥5,0 ppm). In the control group, lead in the hair was detected in 78% of cases, though the concentration was only in 2% of cases higher than so called maximum allowed. Our study clearly indicated deficiency of trace elements, particularly essential ones and high lead contamination in children with short stature. Our

  6. Cadmium in hair of school children living in Tarragona Province, Spain. Relationship to age, sex, and environmental factors.

    PubMed

    Bosque, M A; Domingo, J L; Llobet, J M; Corbella, J

    1991-02-01

    Cadmium concentrations were determined in the hair of 226 school children in an industrial and in a rural area of Tarragona Province (NE Spain). The influence of sex, age, hair color, smoking habits of the household members, and parents' occupation on the children's hair cadmium levels was also evaluated. Children living in the industrial area had much more cadmium in their hair than those living in the rural area (median: 0.327 vs 0.002; arithmetic mean: 0.401 vs 0.119 micrograms/g). Girls had more cadmium in their hair than boys, and cadmium levels decreased with the age independently of the sex. Smoking habits and parents' occupation also influenced the hair cadmium content in the children examined. In contrast, hair color has no influence on hair cadmium values. PMID:1709030

  7. Accumulation of dietary methylmercury in the testes of the adult brown norway rat: Impaired testicular and epididymal function

    SciTech Connect

    Friedmann, A.S.; Chen, H.; Zirkin, B.R.; Rabuck, L.D.

    1998-05-01

    The widespread consumption of fish containing elevated concentrations of methylmercury has prompted concern over the health effects of such a diet. Previous studies with rodents have indicated that exposure to dietary mercury (Hg) impairs male reproductive health. However, adverse effects were observed following doses in the range of milligrams per kilogram of body weight, whereas typical human consumption in the United States is in the range of micrograms per kilogram of body weight. This study examined the effects of dietary Hg on male rats using levels of the metal that are more similar to those typically consumed by humans. For 19 weeks, adult male Brown Norway rats were administered methylmercury twice weekly at 0.8, 8.0, or 80 {micro}g/kg. Intratesticular testosterone levels in the high-dose group were reduced by 44$, suggesting that steroidogenesis in these animals was dramatically impaired. Although sperm production was not significantly affected, numbers of sperm in the cauda epididymides of the high-dose group were reduced by 17%. Furthermore, there was a negative correlation between fertility and testicular Hg content. These results raise the possibility that exposure to Hg at levels consumed by humans may result in steroidogenic impairment, reduced sperm counts, and fertility problems.

  8. Oxygen intrusion into anoxic fjords leads to increased methylmercury availability

    NASA Astrophysics Data System (ADS)

    Veiteberg Braaten, Hans Fredrik; Pakhomova, Svetlana; Yakushev, Evgeniy

    2013-04-01

    Mercury (Hg) appears in the oxic surface waters of the oceans at low levels (sub ng/L). Because inorganic Hg can be methylated into the toxic and bioaccumulative specie methylmercury (MeHg) levels can be high at the top of the marine food chain. Even though marine sea food is considered the main risk driver for MeHg exposure to people most research up to date has focused on Hg methylation processes in freshwater systems. This study identifies the mechanisms driving formation of MeHg during oxygen depletion in fjords, and shows how MeHg is made available in the surface water during oxygen intrusion. Studies of the biogeochemical structure in the water column of the Norwegian fjord Hunnbunn were performed in 2009, 2011 and 2012. In autumn of 2011 mixing flushing events were observed and lead to both positive and negative effects on the ecosystem state in the fjord. The oxygenated water intrusions lead to a decrease of the deep layer concentrations of hydrogen sulfide (H2S), ammonia and phosphate. On the other hand the intrusion also raised the H2S boundary from 8 m to a shallower depth of just 4 m. Following the intrusion was also observed an increase at shallower depths of nutrients combined with a decrease of pH. Before flushing events were observed concentrations of total Hg (TotHg) increased from 1.3 - 1.7 ng/L in the surface layer of the fjord to concentrations ranging from 5.2 ng/L to 6.4 ng/L in the anoxic zone. MeHg increased regularly from 0.04 ng/L in the surface water to a maximum concentration of 5.2 ng/L in the deeper layers. This corresponds to an amount of TotHg present as MeHg ranging from 2.1 % to 99 %. The higher concentrations of MeHg in the deeper layer corresponds to an area where no oxygen is present and concentrations of H2S exceeds 500 µM, suggesting a production of MeHg in the anoxic area as a result of sulphate reducing bacteria activity. After flushing the concentrations of TotHg showed a similar pattern ranging from 0.6 ng/L in the

  9. Stress and the Hair Growth Cycle: Cortisol-Induced Hair Growth Disruption.

    PubMed

    Thom, Erling

    2016-08-01

    The stress hormone, cortisol, is known to affect the function and cyclic regulation of the hair follicle. When cortisol is present at high levels it has been demonstrated to reduce the synthesis and accelerate the degradation of important skin elements, namely hyaluronan and proteoglycans by approximately 40%. The following discussion outlines the relationship between stress, cortisol, and the effect on the normal function of the hair follicle. As a result of this connection, important correlations have been established in the literature to form a basis for novel, effective treatments of stress-related hair growth disorders.
    Amongst various treatment methods and substances, oral supplementation with a specific bioavailable proteoglycan stands out as a promising new therapeutic treatment method.

    J Drugs Dermatol. 2016;15(8):1001-1004. PMID:27538002

  10. Optical properties of human hair

    NASA Astrophysics Data System (ADS)

    Altshuler, Gregory B.; Ilyasov, Ildar K.; Prikhodko, Constantin V.

    1995-01-01

    Optical properties of human hair are the subject of great interest for the realization of any possible cosmetic applications. This paper represents the results of hair microstructure as an optical substance investigation, indicates melanin and keratin absorption spectra, and shows experimentally discovered anisotropia of optical properties of human hair. Radiation weakening coefficient value at the range from 450 up to 800 nm is estimated. Thresholds of hair destruction by Nd, Ho, Cu, and Er laser radiation are obtained. Perspectives of laser application for epilation and other medical purposes are evaluated.

  11. Nanomechanical responses of human hair.

    PubMed

    Samanta, Aniruddha; Bhattacharya, Manjima; Dalui, Srikanta; Acharya, Megha; Das, Pradip Sekhar; Chanda, Dipak Kr; Acharya, Saikat Deb; Sivaraman, Sankar Kalidas; Nath, Shekhar; Mandal, Ashok Kumar; Ghosh, Jiten; Mukhopadhyay, Anoop Kumar

    2016-03-01

    Here we report the first ever studies on nanomechanical properties e.g., nanohardness and Young׳s modulus for human hair of Indian origin. Three types of hair samples e.g., virgin hair samples (VH), bleached hair samples (BH) and Fe-tannin complex colour treated hair samples (FT) with the treatment by a proprietary hair care product are used in the present work. The proprietary hair care product involves a Fe-salt based formulation. The hair samples are characterized by optical microscopy, atomic force microscopy, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy (EDAX) genesis line map, EDAX spot mapping, nanoindentation, tensile fracture, and X-ray diffraction techniques. The nanoindentation studies are conducted on the cross-sections of the VH, BH and FT hair samples. The results prove that the nanomechanical properties e.g., nanohardness and Young׳s modulus are sensitive to measurement location e.g., cortex or medulla and presence or absence of the chemical treatment. Additional results obtained from the tensile fracture experiments establish that the trends reflected from the evaluations of the nanomechanical properties are general enough to hold good. Based on these observations a schematic model is developed. The model explains the present results in a qualitative yet satisfactory manner. PMID:26719934

  12. Quantum hair and quantum gravity

    SciTech Connect

    Coleman, S. ); Krauss, L.M. ); Preskill, J. ); Wilczek, F. )

    1992-01-01

    A black hole may carry quantum numbers that are not associated with massless gauge fields, contrary to the spirit of the 'no-hair' theorems. The 'quantum hair' is invisible in the classical limit, but measurable via quantum interference experiments. Quantum hair alters the temperature of the radiation emitted by a black hole. It also induces non-zero expectation values for fields outside the event horizon; these expectation values are non-perturbative in [Dirac h], and decay exponentially far from the hole. The existence of quantum hair demonstrates that a black hole can have an intricate quantum-mechanical structure that is completely missed by standard semiclassical theory.

  13. Methylmercury is the predominant form of mercury in bird eggs: a synthesis

    USGS Publications Warehouse

    Ackerman, Joshua T.; Herzog, Mark P.; Schwarzbach, Steven E.

    2013-01-01

    Bird eggs are commonly used in mercury monitoring programs to assess methylmercury contamination and toxicity to birds. However, only 6% of >200 studies investigating mercury in bird eggs have actually measured methylmercury concentrations in eggs. Instead, studies typically measure total mercury in eggs (both organic and inorganic forms of mercury), with the explicit assumption that total mercury concentrations in eggs are a reliable proxy for methylmercury concentrations in eggs. This assumption is rarely tested, but has important implications for assessing risk of mercury to birds. We conducted a detailed assessment of this assumption by (1) collecting original data to examine the relationship between total and methylmercury in eggs of two species, and (2) reviewing the published literature on mercury concentrations in bird eggs to examine whether the percentage of total mercury in the methylmercury form differed among species. Within American avocets (Recurvirostra americana) and Forster’s terns (Sterna forsteri), methylmercury concentrations were highly correlated (R2 = 0.99) with total mercury concentrations in individual eggs (range: 0.03–7.33 μg/g fww), and the regression slope (log scale) was not different from one (m = 0.992). The mean percentage of total mercury in the methylmercury form in eggs was 97% for American avocets (n = 30 eggs), 96% for Forster’s terns (n = 30 eggs), and 96% among all 22 species of birds (n = 30 estimates of species means). The percentage of total mercury in the methylmercury form ranged from 63% to 116% among individual eggs and 82% to 111% among species means, but this variation was not related to total mercury concentrations in eggs, foraging guild, nor to a species life history strategy as characterized along the precocial to altricial spectrum. Our results support the use of total mercury concentrations to estimate methylmercury concentrations in bird eggs.

  14. Methylmercury is the predominant form of mercury in bird eggs: a synthesis.

    PubMed

    Ackerman, Joshua T; Herzog, Mark P; Schwarzbach, Steven E

    2013-02-19

    Bird eggs are commonly used in mercury monitoring programs to assess methylmercury contamination and toxicity to birds. However, only 6% of >200 studies investigating mercury in bird eggs have actually measured methylmercury concentrations in eggs. Instead, studies typically measure total mercury in eggs (both organic and inorganic forms of mercury), with the explicit assumption that total mercury concentrations in eggs are a reliable proxy for methylmercury concentrations in eggs. This assumption is rarely tested, but has important implications for assessing risk of mercury to birds. We conducted a detailed assessment of this assumption by (1) collecting original data to examine the relationship between total and methylmercury in eggs of two species, and (2) reviewing the published literature on mercury concentrations in bird eggs to examine whether the percentage of total mercury in the methylmercury form differed among species. Within American avocets (Recurvirostra americana) and Forster's terns (Sterna forsteri), methylmercury concentrations were highly correlated (R(2) = 0.99) with total mercury concentrations in individual eggs (range: 0.03-7.33 μg/g fww), and the regression slope (log scale) was not different from one (m = 0.992). The mean percentage of total mercury in the methylmercury form in eggs was 97% for American avocets (n = 30 eggs), 96% for Forster's terns (n = 30 eggs), and 96% among all 22 species of birds (n = 30 estimates of species means). The percentage of total mercury in the methylmercury form ranged from 63% to 116% among individual eggs and 82% to 111% among species means, but this variation was not related to total mercury concentrations in eggs, foraging guild, nor to a species life history strategy as characterized along the precocial to altricial spectrum. Our results support the use of total mercury concentrations to estimate methylmercury concentrations in bird eggs. PMID:23331121

  15. Removing Pubic Hair (For Young Women)

    MedlinePlus

    ... the-counter “depilatories” or cream hair removers: This method of hair removal is painless, but it’s important ... the cloth strip is quickly pulled off. This method of hair removal usually stings (when the cloth ...

  16. Genetics Home Reference: keratoderma with woolly hair

    MedlinePlus

    ... Conditions keratoderma with woolly hair keratoderma with woolly hair Enable Javascript to view the expand/collapse boxes. ... Open All Close All Description Keratoderma with woolly hair is a group of related conditions that affect ...

  17. Hair as a monitor of toxic chemicals exposure

    SciTech Connect

    Jones, P.F.; Adams, S.; Baumgartner, W.A.

    1982-08-31

    The possibility of using hair analysis as a monitor of exposure to hydrazines and polychlorinated biphenyls (PCBs) was investigated. Two female Hartley guinea pigs injected with 0.6 milligrams (mg) of Aroclor-1254 had analyzable concentrations of the PCB in their hair. Analysis was made using glass capillary gas chromatography with an electron-capture detector. The levels ranged from 10 picograms/milligram (pg/mg) of Aroclor-1254 in washed hair to 100pg/mg in unwashed hair. Female Fischer-344 rats injected intraperitoneally with 60mg/kg unsymmetrical dimethyl hydrazine (UDMH), 10mg/kg monomethyl hydrazine (MMH) and/or 10mg/kg hydrazine did not have detectable amounts of these chemicals in their hair at 14, 30 or 42 days after injection. The hair samples did take up the hydrazines when suspended above solutions of the test compounds. The authors concluded that analyzing the PCB content of hair may be useful in providing a history of on-the-job PCB exposure.

  18. Relationship Between Hair Cell Loss and Hearing Loss in Fishes.

    PubMed

    Smith, Michael E

    2016-01-01

    Exposure to intense sound or ototoxic chemicals can damage the auditory hair cells of vertebrates, resulting in hearing loss. Although the relationship between such hair cell damage and auditory function is fairly established for terrestrial vertebrates, there are limited data available to understand this relationship in fishes. Although investigators have measured either the morphological damage of the inner ear or the functional deficits in the hearing of fishes, very few have directly measured both in an attempt to find a relationship between the two. Those studies that have examined both auditory hair cell damage in the inner ear and the resulting hearing loss in fishes are reviewed here. In general, there is a significant linear relationship between the number of hair cells lost and the severity of hearing threshold shifts, although this varies between species and different hair cell-damaging stimuli. After trauma to the fish ear, auditory hair cells are able to regenerate to control level densities. With this regeneration also comes a restoration of hearing. Thus there is also a significant relationship between hair cell recovery and hearing recovery in fishes. PMID:26611069

  19. Dissolved organic matter reduces algal accumulation of methylmercury

    USGS Publications Warehouse

    Luengen, Allison C.; Fisher, Nicholas S.; Bergamaschi, Brian A.

    2012-01-01

    Dissolved organic matter (DOM) significantly decreased accumulation of methylmercury (MeHg) by the diatom Cyclotella meneghiniana in laboratory experiments. Live diatom cells accumulated two to four times more MeHg than dead cells, indicating that accumulation may be partially an energy-requiring process. Methylmercury enrichment in diatoms relative to ambient water was measured by a volume concentration factor (VCF). Without added DOM, the maximum VCF was 32 x 104, and the average VCF (from 10 to 72 h) over all experiments was 12.6 x 104. At very low (1.5 mg/L) added DOM, VCFs dropped by approximately half. At very high (20 mg/L) added DOM, VCFs dropped 10-fold. Presumably, MeHg was bound to a variety of reduced sulfur sites on the DOM, making it unavailable for uptake. Diatoms accumulated significantly more MeHg when exposed to transphilic DOM extracts than hydrophobic ones. However, algal lysate, a labile type of DOM created by resuspending a marine diatom in freshwater, behaved similarly to a refractory DOM isolate from San Francisco Bay. Addition of 67 μM L-cysteine resulted in the largest drop in VCFs, to 0.28 x 104. Although the DOM composition influenced the availability of MeHg to some extent, total DOM concentration was the most important factor in determining algal bioaccumulation of MeHg.

  20. Evolution of our understanding of methylmercury as a health threat.

    PubMed Central

    Watanabe, C; Satoh, H

    1996-01-01

    Methylmercury (MeHg) is recognized as one of the most hazardous environmental pollutants, primarily due to endemic disasters that have occurred repeatedly. A review of the earlier literature on the Minamata outbreak shows how large-scale poisoning occurred and why it could not be prevented. With the repeated occurrences of MeHg poisoning, it gradually became clear that the fetus is much more susceptible to the toxicity of this compound than the adult. Thus, recent epidemiologic studies in several fish-eating populations have focused on the effects of in utero exposure to MeHg. Also, there have been many studies on neurobehavioral effects of in utero exposure to methylmercury in rodents and nonhuman primates. The results of these studies revealed that the effects encompass a wide range of behavioral categories without clear identification of the functional categories distinctively susceptible to MeHg. The overall neurotoxicity of MeHg in humans, nonhuman primates, and rodents appears to have similarities. However, several gaps exist between the human and animal studies. By using the large body of neurotoxicologic data obtained in human populations and filling in such gaps, we can use MeHg as a model agent for developing a specific battery of tests of animal behavior to predict human risks resulting from in utero exposure to other chemicals with unknown neurotoxicity. Approaches developing such a battery are also discussed. PMID:9182044

  1. Embryotoxicity of maternally transferred methylmercury to fathead minnows (Pimephales promelas).

    PubMed

    Bridges, Kristin N; Soulen, Brianne K; Overturf, Carmen L; Drevnick, Paul E; Roberts, Aaron P

    2016-06-01

    Mercury (Hg) is a ubiquitous environmental contaminant and potent neurotoxin. In aquatic environments, Hg can be transformed into methylmercury (MeHg), which bioaccumulates in aquatic food webs, including fish. Methylmercury has been shown to transfer from female fish to developing eggs; however, relatively little is known regarding the effects of maternally transferred MeHg on fish embryos. The present study evaluated the effects of maternally transferred MeHg on fathead minnow (Pimephales promelas) embryos. Embryos were collected from adult fatheads exposed for 30 d to 1 of 3 diets spiked with MeHg: a control diet (0.02 ppm Hg dry wt), a low diet (0.87 ppm Hg dry wt), or a high diet (5.5 ppm Hg dry wt). No effects on spawning frequency, clutch size, or total egg output were observed. In embryos, Hg concentration was a function of female diet and the duration (number of days) of female exposure. Compared with controls, embryos from the low-diet treatment displayed altered embryonic movement patterns (hyperactivity) and decreased time to hatch. Embryos from the high-diet treatment had delayed hatching and increased mortality compared with the other treatments. Collectively, these results suggest that maternally transferred Hg may impact survival, behavior, and developmental milestones of the embryo-larval stages of fish. Environ Toxicol Chem 2016;35:1436-1441. © 2015 SETAC. PMID:26471903

  2. ANALYSIS OF THE MECHANISM OF METHYLMERCURY CYTOTOXICITY

    EPA Science Inventory

    We have investigated MeHg-induced perturbation of the cell cycle kinetics of the murine erythroleukemic cell (MELC) by flow cytometry (FCM). e observed that, at-relatively low levels (2.5 - 7.5 uM), MeHg predominately inhibits progression through the S phase of the cell cycle (in...

  3. Single hair transplantation using the Choi hair transplanter.

    PubMed

    Choi, Y C; Kim, J C

    1992-11-01

    A new procedure for single hair transplantation using the Choi hair transplanter is presented. This operation provides obvious cosmetic advantages in hairline refinement and the reconstruction of eyebrows, eyelashes, beards, and pubic escutcheon. The surgical technique is described in detail. PMID:1430550

  4. Concerns Regarding Hair Cortisol as a Biomarker of Chronic Stress in Exercise and Sport Science

    PubMed Central

    Gerber, Markus; Brand, Serge; Lindwall, Magnus; Elliot, Catherine; Kalak, Nadeem; Herrmann, Christian; Pühse, Uwe; Jonsdottir, Ingibjörg H.

    2012-01-01

    Hair cortisol has the potential to fill the methodological void of long-term cortisol assessment while becoming a widely accepted measure in biopsychology. This review critically examines the applicability and relevance of hair cortisol measurement specifically within the field of exercise and sport science. Current measures of the HPA axis only cover a brief time period, whereas hair cortisol is a unique, non-invasive means to capture long- term cortisol secretion. Studies have shown that individuals who have elevated cortisol secretion (e.g. due to diseases associated with a disturbed activation of the HPA axis or exposure to stressful life events) reveal increased hair cortisol. By contrast, only weak correlations exist between hair cortisol and perceived stress, and the direction of the relationship between hair cortisol levels and mental disorders is unclear. Acute exercise, however, results in increased levels of cortisol that eventually is reflected in higher levels of cortisol in hair samples and studies have shown that exercise intensity is related to hair cortisol level. Thus, elevated hair cortisol levels found among regular exercisers are not necessarily pathological. Thus, one should practice caution when associating athletes’ elevated hair cortisol with poor mental health or disease. Hair cortisol analysis can contribute to a more complete understanding of how long-term cortisol elevation mediates stress-related effects on the health and performance of recreational exercisers and elite athletes. Nevertheless, it is crucial for exercise and sport scientists to consider whether their research questions can be adequately addressed, given that regular intense exercise results in substantially augmented hair cortisol levels. Key points Hair cortisol is a unique, non-invasive and painless means to capture long-term cortisol secretion. Individuals expected to have elevated cortisol secretion (e.g. due to trauma) have increased hair cortisol. Preliminary

  5. The protein transportation pathway from Golgi to vacuoles via endosomes plays a role in enhancement of methylmercury toxicity

    NASA Astrophysics Data System (ADS)

    Hwang, Gi-Wook; Murai, Yasutaka; Takahashi, Tsutomu; Naganuma, Akira

    2014-07-01

    Methylmercury causes serious damage to the central nervous system, but the molecular mechanisms of methylmercury toxicity are only marginally understood. In this study, we used a gene-deletion mutant library of budding yeast to conduct genome-wide screening for gene knockouts affecting the sensitivity of methylmercury toxicity. We successfully identified 31 genes whose deletions confer resistance to methylmercury in yeast, and 18 genes whose deletions confer hypersensitivity to methylmercury. Yeast genes whose deletions conferred resistance to methylmercury included many gene encoding factors involved in protein transport to vacuoles. Detailed examination of the relationship between the factors involved in this transport system and methylmercury toxicity revealed that mutants with loss of the factors involved in the transportation pathway from the trans-Golgi network (TGN) to the endosome, protein uptake into the endosome, and endosome-vacuole fusion showed higher methylmercury resistance than did wild-type yeast. The results of our genetic engineering study suggest that this vesicle transport system (proteins moving from the TGN to vacuole via endosome) is responsible for enhancing methylmercury toxicity due to the interrelationship between the pathways. There is a possibility that there may be proteins in the cell that enhance methylmercury toxicity through the protein transport system.

  6. Perturbation of myelin basic protein (Mbp) splice variant expression in developing rat cerebellum following perinatal exposure to methylmercury.

    PubMed

    Padhi, Bhaja K; Pelletier, Guillaume

    2012-09-18

    Myelin sheaths surrounding axons are essential for saltatory conduction of nerve impulse in the central nervous system. A major protein constituent of myelin sheaths is produced by the myelin basic protein (Mbp) gene, whose expression in oligodendrocytes is conserved across vertebrates. In rat, five Mbp splice variants resulting from alternative splicing of exons 2, 5 and/or 6 are characterized. We developed a PCR-based strategy to quantify individual Mbp splice variants and characterized a sixth Mbp splice variant lacking only exon 5. This newly identified splice variant is predominantly expressed in developing rat brain and has orthologs in mouse and human. Many neurotoxic chemicals can perturb myelination and Mbp gene expression. Regulation of Mbp gene expression at the post-transcriptional level was assessed following perinatal exposure to neurotoxic methylmercury (2 mg/kg b.w./day). Similar reductions in total and individual Mbp splice variant mRNA levels suggest that methylmercury-induced perturbation in Mbp gene expression occurred as a consequence of decreased oligodendrocyte cell population in absence of a significant impact on its post-transcriptional regulation. PMID:22835759

  7. Elevated cortisol content in dog hair with atopic dermatitis.

    PubMed

    Park, Seol-Hee; Kim, Sun-A; Shin, Nam-Shik; Hwang, Cheol-Yong

    2016-05-01

    Canine atopic dermatitis (CAD) is a chronic relapsing inflammatory skin disease occurring in 10% of the canine population. Although most studies have focused on the pathophysiological mechanism involved in CAD, the detrimental impact of CAD on quality of life has received only little attention. Hair cortisol analysis is becoming a valuable tool in monitoring chronic stress. To further validate this approach in CAD, we compared the hair cortisol concentration of atopic dogs with that of healthy conditioned dogs. The extent and severity of cutaneous lesions of atopic dermatitis were assessed according to modified CADESI-03 scores. In addition, skin barrier function was evaluated by measuring transepidermal water loss (TEWL) and stratum corneum conductance. The correlation between CAD severity and hair cortisol concentration was evaluated. The level of hair cortisol evaluated by ELISA assay showed that the atopic dermatitis group had significantly increased cortisol levels compared to that of the healthy control group. A significant positive correlation was identified between hair cortisol level and the CADESI score in CAD patients. The TEWL value of the cubital flexor of the forelimb in the atopic group was significantly higher compared to the healthy controls. These findings imply that the hair cortisol analysis can be an effective and objective biomarker in assessment of long-term stress of CAD patients. PMID:27506086

  8. Investigation of hair dye deposition, hair color loss, and hair damage during multiple oxidative dyeing and shampooing cycles.

    PubMed

    Zhang, Guojin; McMullen, Roger L; Kulcsar, Lidia

    2016-01-01

    Color fastness is a major concern for consumers and manufacturers of oxidative hair dye products. Hair dye loss results from multiple wash cycles in which the hair dye is dissolved by water and leaches from the hair shaft. In this study, we carried out a series of measurements to help us better understand the kinetics of the leaching process and pathways associated with its escape from the fiber. Hair dye leaching kinetics was measured by suspending hair in a dissolution apparatus and monitoring the dye concentration in solution (leached dye) with an ultraviolet-visible spectrophotometer. The physical state of dye deposited in hair fibers was evaluated by a reflectance light microscopy technique, based on image stacking, allowing enhanced depth of field imaging. The dye distribution within the fiber was monitored by infrared spectroscopic imaging of hair fiber cross sections. Damage to the ultrafine structure of the hair cuticle (surface, endocuticle, and cell membrane complex) and cortex (cell membrane complex) was determined in hair cross sections and on the hair fiber surface with atomic force microscopy. Using differential scanning calorimetry, we investigated how consecutive coloring and leaching processes affect the internal proteins of hair. Further, to probe the surface properties of hair we utilized contact angle measurements. This study was conducted on both pigmented and nonpigmented hair to gain insight into the influence of melanin on the hair dye deposition and leaching processes. Both types of hair were colored utilizing a commercial oxidative hair dye product based on pyrazole chemistry. PMID:27319056

  9. Robotic hair restoration.

    PubMed

    Rose, Paul T; Nusbaum, Bernard

    2014-01-01

    The latest innovation to hair restoration surgery has been the introduction of a robotic system for harvesting grafts. This system uses the follicular unit extraction/follicular isolation technique method for harvesting follicular units, which is particularly well suited to the abilities of a robotic technology. The ARTAS system analyzes images of the donor area and then a dual-chamber needle and blunt dissecting punch are used to harvest the follicular units. The robotic technology is now being used in various locations around the world. This article discusses the use of the robotic system, its capabilities, and the advantages and disadvantages of the system. PMID:24267426

  10. Evidence of the direct adsorption of mercury in human hair during occupational exposure to mercury vapour.

    PubMed

    Queipo Abad, Silvia; Rodríguez-González, Pablo; García Alonso, J Ignacio

    2016-07-01

    We have found clear evidence of direct adsorption of mercury in human hair after the occupational exposure to mercury vapour. We have performed both longitudinal analysis of human hair by laser ablation ICP-MS and speciation analysis by gas chromatography ICP-MS in single hair strands of 5 individuals which were occupationally exposed to high levels of mercury vapour and showed acute mercury poisoning symptoms. Hair samples, between 3.5 and 11cm long depending on the individual, were taken ca. three months after exposure. Single point laser ablation samples of 50μm diameter were taken at 1mm intervals starting from the root of the hairs. Sulfur-34 was used as internal standard. The ratio (202)Hg/(34)S showed a distinct pattern of mercury concentration with much lower levels of mercury near the root of the hair and high levels of mercury near the end of the hair. In all cases a big jump in the concentration of mercury in hair occurred at a given distance from the root, between 32 and 42mm depending on the individual, with a high and almost constant concentration of mercury for longer distances to the root. When we took into account the rate of hair growth in humans, 9-15mm/month, the jump in mercury concentration agreed approximately with the dates when the contamination occurred with the new growing hair showing much lower mercury concentration. In some cases the concentration of mercury at the tip of the hair was ca. 1000 times higher than that near the root. Additionally, speciation studies confirmed that mercury in all hair samples was present as inorganic mercury. The only explanation for these results was the direct adsorption of mercury vapour in hair at the time of exposure. PMID:27259347

  11. Taking Care of Your Hair

    MedlinePlus

    ... chemical treatments: Relaxers. Relaxers (straighteners) work by breaking chemical bonds in curly hair. Relaxers containing lye can cause skin irritation and hair breakage. Although "no lye" relaxers may cause less ... before a chemical relaxing treatment can increase these risks. And don' ...

  12. Practical management of hair loss.

    PubMed Central

    Shapiro, J.; Wiseman, M.; Lui, H.

    2000-01-01

    OBJECTIVE: To describe an organized diagnostic approach for both nonscarring and scarring alopecias to help family physicians establish an accurate in-office diagnosis. To explain when ancillary laboratory workup is necessary to confirm the diagnosis. QUALITY OF EVIDENCE: Current diagnostic and therapeutic interventions for hair loss are based on randomized controlled studies, uncontrolled studies, and case series. MEDLINE was searched from January 1966 to December 1998 with the MeSH words alopecia, hair, and alopecia areata. Articles were selected on the basis of experimental design, with priority given to the most current large multicentre controlled studies. Overall global evidence for therapeutic intervention for hair loss is quite strong. MAIN MESSAGE: The most common forms of nonscarring alopecias are androgenic alopecia, telogen effluvium, and alopecia areata. Other disorders include trichotillomania, traction alopecia, tinea capitis, and hair shaft abnormalities. Scarring alopecia is caused by trauma, infections, discoid lupus erythematosus, or lichen planus. Key to establishing an accurate diagnosis is a detailed history, including medication use, systemic illnesses, endocrine dysfunction, hair-care practices, and family history. All hair-bearing sites should be examined. A 4-mm punch biopsy of the scalp is useful, particularly to diagnose scarring alopecias. Once a diagnosis has been established, specific therapy can be initiated. CONCLUSIONS: Diagnosis and management of hair loss is an interesting challenge for family physicians. An organized approach to recognizing characteristic differential features of hair loss disorders is key to diagnosis and management. Images Figure 1 Figure 2 Figure 5 Figure 6 PMID:10925761

  13. Hair Dyes and Cancer Risk

    MedlinePlus

    ... including aromatic amines that were found to cause cancer in animals. In the mid- to late 1970s, however, manufacturers changed the components in dye products to eliminate some of these chemicals ... in hair dyes can cause cancer. Given the widespread use of hair dye products, ...

  14. Human Hair: An Educational Tool.

    ERIC Educational Resources Information Center

    Wells, John

    1983-01-01

    Briefly describes some of the more recent developments in the use of human hairs for such instructional purposes as observing barr bodies and chromosomes, and for culturing to produce cells of both epithelial and fibroblastic morphology. Three main hair categories are also described. (JN)

  15. Laser assisted hair-removal.

    PubMed

    Choudhary, S; Elsaie, M L; Nouri, K

    2009-10-01

    A number of lasers and light devices are now available for the treatment of unwanted hair. The goal of laser hair removal is to damage stem cells in the bulge of the hair follicle by targeting melanin, the endogenous chromophore for laser and light devices utilized to remove hair. The competing chromophores in the skin and hair, oxyhemoglobin and water, have a decreased absorption between 690 nm and 1000 nm, thus making this an ideal range for laser and light sources. Laser hair removal is achieved through follicular unit destruction based on selective photothermolysis. The principle of selective photothermolysis predicts that the thermal injury will be restricted to a given target if there is sufficient selective absorption of light and the pulse duration is shorter than the thermal relaxation time of the target. This review will focus on the mechanisms of laser assisted hair removal and provide an update on the newer technologies emerging in the field of lasers assisted hair removal. PMID:19834437

  16. "Dissection" of a Hair Dryer

    ERIC Educational Resources Information Center

    Eisenstein, Stan; Simpson, Jeff

    2008-01-01

    The electrical design of the common hair dryer is based almost entirely on relatively simple principles learned in introductory physics classes. Just as biology students dissect a frog to see the principles of anatomy in action, physics students can "dissect" a hair dryer to see how principles of electricity are used in a real system. They can…

  17. Light Microscopy of the Hair: A Simple Tool to “Untangle” Hair Disorders

    PubMed Central

    Adya, Keshavmurthy A; Inamadar, Arun C; Palit, Aparna; Shivanna, Ragunatha; Deshmukh, Niranjan S

    2011-01-01

    Light microscopy of the hair forms an important bedside clinical tool for the diagnosis of various disorders affecting the hair. Hair abnormalities can be seen in the primary diseases affecting the hair or as a secondary involvement of hair in diseases affecting the scalp. Hair abnormalities also form a part of various genodermatoses and syndromes. In this review, we have briefly highlighted the light microscopic appearance of various infectious and non-infectious conditions affecting the hair. PMID:21769242

  18. Survival of auditory hair cells.

    PubMed

    Seymour, Michelle L; Pereira, Fred A

    2015-07-01

    The inability of mammals to regenerate auditory hair cells creates a pressing need to understand the means of enhancing hair cell survival following insult or injury. Hair cells are easily damaged by noise exposure, by ototoxic medications and as a consequence of aging processes, all of which lead to progressive and permanent hearing impairment as hair cells are lost. Significant efforts have been invested in designing strategies to prevent this damage from occurring since permanent hearing loss has a profound impact on communication and quality of life for patients. In this mini-review, we discuss recent progress in the use of antioxidants, anti-inflammatories and apoptosis inhibitors to enhance hair cell survival. We conclude by clarifying the distinction between protection and rescue strategies and by highlighting important areas of future research. PMID:25743696

  19. Mammalian tactile hair: divergence from a limited distribution.

    PubMed

    Sarko, Diana K; Rice, Frank L; Reep, Roger L

    2011-04-01

    Mammalian species use tactile hairs to address a variety of perceptual challenges in detecting and responding appropriately to environmental stimuli. With a wide range of functional roles that range from object detection, to fine texture discrimination, to hydrodynamic trail perception, tactile hairs have been adapted for a variety of environmental niches to enhance survival through optimizing detection of somatosensory cues. Because the high level of innervation associated with tactile hairs requires a commensurately high dedication of neural resources, their distribution is restricted to specific regions of the body that encounter stimuli of interest--commonly, the face. However, several species--namely bats, naked mole-rats, hyraxes, manatees, and dugongs--are rare exceptions, with tactile hair distribution that has expanded to cover the entire body. This review examines the behavioral advantages conferred by this unusual trait, the neuroanatomical adaptations that accompany it, and how this pattern might have evolved. PMID:21534996

  20. Performance Evaluation of an Improved GC-MS Method to Quantify Methylmercury in Fish.

    PubMed

    Watanabe, Takahiro; Kikuchi, Hiroyuki; Matsuda, Rieko; Hayashi, Tomoko; Akaki, Koichi; Teshima, Reiko

    2015-01-01

    Here, we set out to improve our previously developed methylmercury analytical method, involving phenyl derivatization and gas chromatography-mass spectrometry (GC-MS). In the improved method, phenylation of methylmercury with sodium tetraphenylborate was carried out in a toluene/water two-phase system, instead of in water alone. The modification enabled derivatization at optimum pH, and the formation of by-products was dramatically reduced. In addition, adsorption of methyl phenyl mercury in the GC system was suppressed by co-injection of PEG200, enabling continuous analysis without loss of sensitivity. The performance of the improved analytical method was independently evaluated by three analysts using certified reference materials and methylmercury-spiked fresh fish samples. The present analytical method was validated as suitable for determination of compliance with the provisional regulation value for methylmercury in fish, set in the Food Sanitation haw. PMID:26156161

  1. Growth and viability of Liaoning Cashmere goat hair follicles during the annual hair follicle cycle.

    PubMed

    Zhang, Q L; Li, J P; Chen, Y; Chang, Q; Li, Y M; Yao, J Y; Jiang, H Z; Zhao, Z H; Guo, D

    2014-01-01

    Here, we studied hair follicle development of Liaoning Cashmere goats. Every month for 1 year, skin samples were collected from five 1.5-year-old female goats, and made into paraffin sections. A number of parameters were measured of primary and secondary hair follicles via microscopic observation including follicle depth, hair bulb width, dermis and epidermis thickness, changes in follicle activity, and histology. The results showed the presence of three phases in the annual hair cycle: anagen, catagen, and telogen. Primary and secondary hair follicle depth varied across the months; however, no significant difference was obtained between adjacent months (P>0.05). Primary hair follicles had a bigger hair bulb width compared to secondary hair follicles; however, this difference declined during hair follicle developed in anagen. As hair follicle growth slowed, the hair bulb broadened, and hair root depth became shallower. During the entire hair cycle, hair follicle depth and dermis thickness were positively correlated; however, this relationship was not significant (P>0.05) for primary and secondary hair follicle density and the ratio of secondary hair follicle density and primary hair follicle density (S/P ratio). In addition, new and old primary hair follicles coexisted with secondary hair follicles. Finally, secondary hair follicles had a higher activity rate compared to primary hair follicle in adult Liaoning Cashmere goats in certain months. PMID:25036348

  2. Mercury in human hair due to environment and diet: a review.

    PubMed Central

    Airey, D

    1983-01-01

    Hair mercury levels increase with the amount of fish in the diet and the amount of mercury in the fish species consumed. If hair mercury levels in people throughout the world were monitored by a standard analytical procedure, the results would indicate locations where people's body burden of mercury is high enough to be subclinically unhealthy and where controls on environmental emissions might be beneficial. The relationship of hair mercury concentration to the method of sampling and analysis of hair, the analysis of the results, the amount of fish consumed, the country and location from which samples were taken and the age, sex and occupation of the donor is discussed. PMID:6653535

  3. Antiretroviral concentrations in small hair samples as a feasible marker of adherence in rural Kenya.

    PubMed

    Hickey, Matthew D; Salmen, Charles R; Tessler, Robert A; Omollo, Dan; Bacchetti, Peter; Magerenge, Richard; Mattah, Brian; Salmen, Marcus R; Zoughbie, Daniel; Fiorella, Kathryn J; Geng, Elvin; Njoroge, Betty; Jin, Chengshi; Huang, Yong; Bukusi, Elizabeth A; Cohen, Craig R; Gandhi, Monica

    2014-07-01

    Antiretroviral hair levels objectively quantify drug exposure over time and predict virologic responses. We assessed the acceptability and feasibility of collecting small hair samples in a rural Kenyan cohort. Ninety-five percentage of participants (354/373) donated hair. Although median self-reported adherence was 100% (interquartile range, 96%-100%), a wide range of hair concentrations likely indicates overestimation of self-reported adherence and the advantages of a pharmacologic adherence measure. Higher nevirapine hair concentrations observed in women and older adults require further study to unravel behavioral versus pharmacokinetic contributors. In resource-limited settings, hair antiretroviral levels may serve as a low-cost quantitative biomarker of adherence. PMID:24694932

  4. Maternal transfer of inorganic mercury and methylmercury in aquatic and terrestrial arthropods.

    PubMed

    Saxton, Heidi J; Goodman, James R; Collins, Jeffrey N; Black, Frank J

    2013-11-01

    The transfer of mercury from females to their offspring plays an important role in mercury accumulation and toxicity during early development. To quantify the transfer of inorganic mercury and methylmercury from female arthropods to their eggs, the authors collected and analyzed brine shrimp (Artemia franciscana), wolf spiders (Alopecosa spp.), and their attached eggs from aquatic and terrestrial ecosystems at the Great Salt Lake, Utah, USA. Essentially all of the mercury in both the female brine shrimp and their eggs was methylmercury (94 ± 17% and 90 ± 21%, respectively). The brine shrimp eggs had methylmercury concentrations that were 84 ± 2% lower than in the females, reflecting the fact that females transferred 45 ± 4% of their total body mass but only 11 ± 3% of their methylmercury burden to their eggs. As a result of this sequestration, the concentration of methylmercury in the female brine shrimp increased by 62 ± 8% during egg formation. The percentage of the total mercury that was methylmercury in female wolf spiders (77 ± 21%) was similar to that in their egg masses (81 ± 19%), indicating similar maternal transfer efficiencies for inorganic mercury and methylmercury in these invertebrates. The concentration of inorganic mercury and methylmercury in the female spiders was the same as in their eggs. These arachnids transferred 48 ± 9% of their total body mass, 55 ± 13% of their inorganic mercury, and 50 ± 9% of their methylmercury to their egg masses. Thus, female wolf spiders do not have the ability to reduce the transfer of methylmercury to their eggs, nor does this process represent an important pathway for the depuration of mercury. The present study demonstrates that although some arthropods have mechanisms to minimize the transfer of methylmercury to their eggs and reduce the potential for mercury toxicity during early development, other arthropods do not. PMID:23939924

  5. Significant damage of the skin and hair following hair bleaching.

    PubMed

    Jeong, Mi-Sook; Lee, Chang-Moon; Jeong, Won-Ji; Kim, Seong-Jin; Lee, Ki-Young

    2010-10-01

    Scalp burns can be caused by hair bleaching with excess procedures such as unnecessary heating and excessive treatment with bleaching agents. The aim of this study was to investigate the morphological and histological changes of the hair and skin after bleaching. Ammonium persulfate and hydrogen peroxide (6% or 9%) solution mixed at a ratio of 1:2 (weight ratio) were sufficiently applied to human hairs and rat skin. The bleached hairs were brightened up to yellow by increasing the concentration of hydrogen peroxide and time of bleach treatment. After bleaching, scanning electron microscopy (SEM) was used to observe that the cuticle scales of the hairs were irregular and lifted. The mechanical properties of the bleached hairs, such as tensile strength and elongation, were slightly different than the untreated hairs. The tested rat skin showed severe swelling after treatment of the bleaching agent (9% hydrogen peroxide). The rat skin bleached with 9% hydrogen peroxide exhibited epidermal thinning and subepidermal vesicle formation. The extracellular matrix of the skin was seriously disrupted after bleaching. Therefore, the use of only suitable bleaching procedures is suggested in order to avoid injuries. PMID:20860738

  6. Diversity in human hair growth, diameter, colour and shape. An in vivo study on young adults from 24 different ethnic groups observed in the five continents.

    PubMed

    Loussouarn, Geneviève; Lozano, Isabelle; Panhard, Ségolène; Collaudin, Catherine; El Rawadi, Charles; Genain, Gilles

    2016-04-01

    Based on previous findings, from a worldwide study, classified the shapes of human hair into 8 major types, from straight to highly curly. This clearly extended the usual classification of hair into African, Asian or Caucasian types. However, determinations of hair growth parameters and hair density were excluded from such studies. To measure and compare the hair growth profiles of young adults without alopecia living in the five continents. 2249 young adults (18-35 years, females and males) without alopecia, originating from 24 various human ethnic groups were included in the study. Total hair density, telogen percentage and growth rate on three different scalp areas were measured, using non-invasive validated techniques. Natural hair colour level, curliness and hair diameter were additionally recorded, when practically possible. Diversity in hair growth parameters among the entire cohort was a key finding, with differences linked to scalp area, gender and geographic origin. Statistical approaches depicted African hair as having lower density and a slower growth rate. Asian hair showed a thicker diameter, with faster growth. Caucasian hair showed a high total hair density. On the one hand, this inter-continental study of hair growth parameters provides initial valuable base-line data on hair in young adults without alopecia, and on the other hand, further extends our knowledge of this unique human appendage, with some mosaic features, observed worldwide. PMID:27019510

  7. Increases in methylmercury export from a sulfate-amended peatland: A consequence of an altered microbial consortia?

    NASA Astrophysics Data System (ADS)

    Branfireun, B.; Krabbenhoft, D.; Fowle, D.; Jeremiason, J.

    2004-05-01

    An experiment at the Marcell Experimental Forest, Minnesota is ongoing to test the hypothesis that increased atmospheric sulfate deposition to northern peatlands is responsible for increased methylmercury yields from these ecosystems. A peatland, divided into an upslope control portion and a downslope experimental portion, has had elevated levels of sulfate applied to the experimental portion using an extensive irrigation network for several seasons. Increases in methylmercury yield from the system were apparent early in the experimental manipulation. In 2002, peat cores were extracted from the control and experimental areas of the peatland to evaluate whether or not changes in the peat sulfur geochemistry, microbial community structure, and/or mercury methylation potential could be attributed to the sulfate additions. Mercury methylation potential was assessed using a stable isotope addition to incubated intact peat cores, which were subsequently sliced and frozen until analyses. The microbial community structure was assessed using a modified solid-phase extraction followed by phospholipid fatty acid (PLFA) analyses. Although only minor differences in sulfur geochemistry and methylation potential were detected, the treatment cores had increased abundances of Desulfovibrio-group and Desulfobacter-group biomarkers compared to the control cores, and the effect was greatest in the near surface peat. In the control cores, the abundances of sulfate-reducers in both groups increased with depth. These results suggest that increased sulfate loading may cause a shift in microbial community structure and abundance in favour of known mercury methylators.

  8. Mercury and methylmercury concentrations in high altitude lakes and fish (Arctic charr) from the French Alps related to watershed characteristics.

    PubMed

    Marusczak, Nicolas; Larose, Catherine; Dommergue, Aurélien; Paquet, Serge; Beaulne, Jean-Sébastien; Maury-Brachet, Régine; Lucotte, Marc; Nedjai, Rachid; Ferrari, Christophe P

    2011-04-15

    Total mercury (THg) and methylmercury (MeHg) concentrations were measured in the muscle of Arctic charr (Salvelinus alpinus) and in the water column of 4 lakes that are located in the French Alps. Watershed characteristics were determined (6 coverage classes) for each lake in order to evaluate the influence of watershed composition on mercury and methylmercury concentrations in fish muscle and in the water column. THg and MeHg concentrations in surface water were relatively low and similar among lakes and watershed characteristics play a major role in determining water column Hg and MeHg levels. THg muscle concentrations for fish with either a standardized length of 220mm, a standardized age of 5 years or for individualuals did not exceed the 0.5mg kg(-1) fish consumption advisory limit established for Hg by the World Health Organization (WHO, 1990). These relatively low THg concentrations can be explained by watershed characteristics, which lead to short Hg residence time in the water column, and also by the short trophic chain that is characteristic of mountain lakes. Growth rate did not seem to influence THg concentrations in fish muscles of these lakes and we observed no relationship between fish Hg concentrations and altitude. This study shows that in the French Alps, high altitude lakes have relatively low THg and MeHg concentrations in both the water column and in Arctic charr populations. Therefore, Hg does not appear to present a danger for local populations and the fishermen of these lakes. PMID:21371737

  9. Harvesting electricity from human hair.

    PubMed

    Tulachan, Brindan; Singh, Sushil K; Philip, Deepu; Das, Mainak

    2016-01-01

    Electrical conductivity of human hair is a debatable issue among hair experts and scientists. There are unsubstantiated claims that hair conducts electricity. However, hair experts provided ample evidence that hair is an insulator. Although wet hair exhibited drastic reduction in resistivity; scientists regarded hair as a proton semiconductor at the best. Here, we demonstrate that hair filaments generate electricity on absorbing water vapor between 50 degrees and 80 degrees C. This electricity can operate low power electronic systems. Essentially, we are exposing the hydrated hair polymer to a high temperature (50 degrees-80 degrees C). It has long been speculated that when certain biopolymers are simultaneously hydrated and exposed to high temperature, they exhibit significant proton hopping at a specific temperature regime. This happens due to rapid movement of water molecules on the polymer surface. This lead us to speculate that the observed flow of current is partly ionic and partly due to "proton hopping" in the hydrated nano spaces of hair filament. Such proton hopping is exceptionally high when the hydrated hair polymer is exposed to a temperature between 50 degrees and 80 degrees C. Differential scanning calorimetry data further corroborated the results and indicated that indeed at this temperature range, there is an enormous movement of water molecules on the hair polymer surface. This enormously rapid movement of water molecules lead to the "making and breaking" of innumerable hydrogen bonds and thus resulting in hopping of the protons. What is challenging is "how to tap these hopping protons to obtain useful electricity?" We achieved this by placing a bundle of hair between two different electrodes having different electro negativities, and exposing it to water vapor (water + heat). The two different electrodes offered directionality to the hopping protons and the existing ions and thus resulting in the generation of useful current. Further, by

  10. Methylmercury inhibits prolactin release in a cell line of pituitary origin

    PubMed Central

    Maués, L.A.L.; Macchi, B.M.; Crespo-López, M.E.; Nasciutti, L.E.; Picanço-Diniz, D.L.W.; Antunes-Rodrigues, J.; do Nascimento, J.L.M.

    2015-01-01

    Heavy metals, such as methylmercury, are key environmental pollutants that easily reach human beings by bioaccumulation through the food chain. Several reports have demonstrated that endocrine organs, and especially the pituitary gland, are potential targets for mercury accumulation; however, the effects on the regulation of hormonal release are unclear. It has been suggested that serum prolactin could represent a biomarker of heavy metal exposure. The aim of this study was to evaluate the effect of methylmercury on prolactin release and the role of the nitrergic system using prolactin secretory cells (the mammosomatotroph cell line, GH3B6). Exposure to methylmercury (0-100 μM) was cytotoxic in a time- and concentration-dependent manner, with an LC50 higher than described for cells of neuronal origin, suggesting GH3B6 cells have a relative resistance. Methylmercury (at exposures as low as 1 μM for 2 h) also decreased prolactin release. Interestingly, inhibition of nitric oxide synthase by N-nitro-L-arginine completely prevented the decrease in prolactin release without acute neurotoxic effects of methylmercury. These data indicate that the decrease in prolactin production occurs via activation of the nitrergic system and is an early effect of methylmercury in cells of pituitary origin. PMID:26108095

  11. [Methylmercury exposure in the general population; toxicokinetics; differences by gender, nutritional and genetic factors].

    PubMed

    González-Estecha, Montserrat; Bodas-Pinedo, Andrés; Guillén-Pérez, José Jesús; Rubio-Herrera, Miguel Ángel; Ordóñez-Iriarte, José M; Trasobares-Iglesias, Elena M; Martell-Claros, Nieves; Martínez-Álvarez, Jesús Román; Farré-Rovira, Rosaura; Herráiz-Martínez, Miguel Ángel; Martínez-Astorquiza, Txantón; Calvo-Manuel, Elpidio; Sáinz-Martín, María; Bretón-Lesmes, Irene; Prieto-Menchero, Santiago; Llorente-Ballesteros, M Teresa; Martínez-García, M José; Salas-Salvadó, Jordi; Bermejo-Barrera, Pilar; García-Donaire, José Antonio; Cuadrado-Cenzual, M Ángeles; Gallardo-Pino, Carmen; Moreno-Rojas, Rafael; Arroyo-Fernández, Manuel; Calle-Pascual, Alfonso

    2014-01-01

    Mercury is an environmental toxicant that causes numerous adverse effects on human health and natural ecosystems. The factors that determine the existance of adverse effects, as well as their severity are, among others: the chemical form of mercury (elemental, inorganic, organic), dosis, age, period of exposure, pathways of exposure and environmental, nutritional and genetic factors. In the aquatic cycle of mercury, once it has been deposited, it is transformed into methylmercury due to the action of certain sulphate-reducing bacteria, which bioaccumulates in the aquatic organisms and moves into the food chain. The methylmercury content of large, long-lived fish such as swordfish, shark, tuna or marlin, is higher. Methylmercury binds to protein in fish and is therefore not eliminated by cleaning or cooking the fish. Fetuses and small children are more vulnerable to the neurotoxic effects of methylmercury from the consumption of contaminated fish. Methylmercury is absorbed in the gastrointestinal tract and crosses the blood-brain barrier and the placenta. The intake of certain dietary components such as polyunsaturated fatty acids, selenium, fiber, thiol compounds, certain phytochemicals and other nutrients can modify methylmercury bioaccesibility and its toxicity. Apart from environmental factors, genetic factors can influence mercury toxicity and explain part of the individual vulnerability. PMID:25365001

  12. Effect of hair dyes and bleach on the hair protein patterns as revealed by isoelectric focusing.

    PubMed

    Nagai, A; Komoriya, H; Bunai, Y; Yamada, S; Jiang, X Y; Ohya, I

    1991-06-01

    The effect of hair dyes, i.e., temporary, semi-permanent, or permanent hair dyes, or hair bleach on the isoelectric focusing (IEF) hair protein patterns was studied. A permanent hair dye (metallic, alkaline oxidative, or acidic oxidative) and hair bleach induced changes in the IEF hair protein patterns and in the intensity of hair protein bands. The changes in the IEF patterns, caused by the alkaline oxidative dye or the bleach, are considered to result from the combined effect of an alkaline agent and an oxidative agent in the alkaline oxidative dye and in the hair bleach. PMID:1889397

  13. Role of thymosin beta 4 in hair growth.

    PubMed

    Gao, Xiao-Yu; Hou, Fang; Zhang, Zhi-Peng; Nuo, Ming-Tu; Liang, Hao; Cang, Ming; Wang, Zhi-Gang; Wang, Xin; Xu, Teng; Yan, Le-Yan; Guo, Xu-Dong; Liu, Dong-Jun

    2016-08-01

    Although thymosin beta 4 (Tβ4) is known to play a role in hair growth, its mechanism of action is unclear. We examined the levels of key genes in a Tβ4 epidermal-specific over-expressing mouse model and Tβ4 global knockout mouse model to explore how Tβ4 affects hair growth. By depilation and histological examination of the skin, we confirmed the effect of Tβ4 on hair growth, the number of hair shafts and hair follicle (HF) structure. The mRNA and protein expression of several genes involved in hair growth were detected by real-time PCR and western blotting, respectively. Changes in the expression of β-catenin and Lef-1, the two key molecules in the Wnt signaling pathway, were similar to the changes observed in Tβ4 expression. We also found that compared to the control mice, the mRNA and protein expression of MMP-2 and VEGF were increased in the Tβ4 over-expressing mice, while the level of E-cadherin (E-cad) remained the same. Further, in the Tβ4 global knockout mice, the mRNA and protein levels of MMP-2 and VEGF decreased dramatically and the level of E-cad was stable. Based on the above results, we believe that Tβ4 may regulate the levels of VEGF and MMP-2 via the Wnt/β-catenin/Lef-1 signaling pathway to influence the growth of blood vessels around HFs and to activate cell migration. Tβ4 may have potential for the treatment of hair growth problems in adults, and its effects should be further confirmed in future studies. PMID:27130465

  14. Cell wall-associated ROOT HAIR SPECIFIC 10, a proline-rich receptor-like kinase, is a negative modulator of Arabidopsis root hair growth.

    PubMed

    Hwang, Youra; Lee, Hyodong; Lee, Young-Sook; Cho, Hyung-Taeg

    2016-03-01

    Plant cell growth is restricted by the cell wall, and cell wall dynamics act as signals for the cytoplasmic and nuclear events of cell growth. Among various receptor kinases, ROOT HAIR SPECIFIC 10 (RHS10) belongs to a poorly known receptor kinase subfamily with a proline-rich extracellular domain. Here, we report that RHS10 defines the root hair length of Arabidopsis thaliana by negatively regulating hair growth. RHS10 modulates the duration of root hair growth rather than the growth rate. As poplar and rice RHS10 orthologs also showed a root hair-inhibitory function, this receptor kinase-mediated function appears to be conserved in angiosperms. RHS10 showed a strong association with the cell wall, most probably through its extracellular proline-rich domain (ECD). Deletion analysis of the ECD demonstrated that a minimal extracellular part, which includes a few proline residues, is required for RHS10-mediated root hair inhibition. RHS10 suppressed the accumulation of reactive oxygen species (ROS) in the root, which are necessary for root hair growth. A yeast two-hybrid screening identified an RNase (RNS2) as a putative downstream target of RHS10. Accordingly, RHS10 overexpression decreased and RHS10 loss increased RNA levels in the hair-growing root region. Our results suggest that RHS10 mediates cell wall-associated signals to maintain proper root hair length, at least in part by regulating RNA catabolism and ROS accumulation. PMID:26884603

  15. Cell wall-associated ROOT HAIR SPECIFIC 10, a proline-rich receptor-like kinase, is a negative modulator of Arabidopsis root hair growth

    PubMed Central

    Hwang, Youra; Lee, Hyodong; Lee, Young-Sook; Cho, Hyung-Taeg

    2016-01-01

    Plant cell growth is restricted by the cell wall, and cell wall dynamics act as signals for the cytoplasmic and nuclear events of cell growth. Among various receptor kinases, ROOT HAIR SPECIFIC 10 (RHS10) belongs to a poorly known receptor kinase subfamily with a proline-rich extracellular domain. Here, we report that RHS10 defines the root hair length of Arabidopsis thaliana by negatively regulating hair growth. RHS10 modulates the duration of root hair growth rather than the growth rate. As poplar and rice RHS10 orthologs also showed a root hair-inhibitory function, this receptor kinase-mediated function appears to be conserved in angiosperms. RHS10 showed a strong association with the cell wall, most probably through its extracellular proline-rich domain (ECD). Deletion analysis of the ECD demonstrated that a minimal extracellular part, which includes a few proline residues, is required for RHS10-mediated root hair inhibition. RHS10 suppressed the accumulation of reactive oxygen species (ROS) in the root, which are necessary for root hair growth. A yeast two-hybrid screening identified an RNase (RNS2) as a putative downstream target of RHS10. Accordingly, RHS10 overexpression decreased and RHS10 loss increased RNA levels in the hair-growing root region. Our results suggest that RHS10 mediates cell wall-associated signals to maintain proper root hair length, at least in part by regulating RNA catabolism and ROS accumulation. PMID:26884603

  16. Hormones in Infant Hair at Birth Provide a Window into the Fetal Environment

    PubMed Central

    Kapoor, Amita; Lubach, Gabriele; Hedman, Curtis; Ziegler, Toni E.; Coe, Christopher L.

    2014-01-01

    Background It is established that maternal parity can affect infant growth and risk for several disorders, but the prenatal endocrine milieu that contributes to these outcomes is still largely unknown. Recently, it has been shown that hormones deposited in hair can provide a retrospective reflection of hormone levels while the hair was growing. Taking advantage of this finding, our study utilized hair at birth to investigate if maternal parity affected fetal hormone exposure during late gestation. Methods Hair was collected from primiparous and multiparous mother and infant monkeys at birth and used to determine steroid hormones embedded in hair while the infant was in utero. An LC/MS/MS technique was refined, which enabled the simultaneous measurement of 8 hormones. Results Hormone concentrations were dramatically higher in neonatal compared to maternal hair, reflecting extended fetal exposure as the first hair was growing. Further, hair cortisone was higher in primiparous mothers and infants when compared to the multiparous dyads. Conclusion This research demonstrates that infant hair can be used to track fetal hormone exposure and a panel of steroid hormones can be quantified from hair specimens. Given the utility in nonhuman primates, this approach can be translated to a clinical setting with human infants. PMID:24418932

  17. DOE/FDA/EPA: Workshop on methylmercury and human health

    SciTech Connect

    Moskowitz, P.D.; Saroff, L.; Bolger, M.; Cicmanec, J.; Durkee, S.

    1994-12-31

    In the US the general population is exposed to methylmercury (MeHg) principally through the consumption of fish. There is continuing discussion about the sources of this form of mercury (Hg), the magnitudes and trends in exposures to consumers, and the significance of the sources and their contributions to human health. In response to these discussions, the US Department of Energy, the US Food and Drug Administration, and the US Environmental Protection Agency cosponsored a two-day workshop to discuss data and methods available for characterizing the risk to human health presented by MeHg. This workshop was attended by 45 individuals representing various Federal and state organizations and interested stakeholders. The agenda covered: Agency interests; probabilistic approach to risk assessment; emission sources; atmospheric transport; biogeochemical cycling; exposure assessment; health effects of MeHg; and research needs.

  18. Why dissolved organic matter (DOM) enhances photodegradation of methylmercury

    SciTech Connect

    Qian, Yun; Yin, Xiangping Lisa; Brooks, Scott C; Liang, Liyuan; Gu, Baohua

    2014-01-01

    Methylmercury (MeHg) is known to degrade photochemically, but it remains unclear what roles naturally dissolved organic matter (DOM) and complexing organic ligands play in MeHg photodegradation. Here we investigate the rates and mechanisms of MeHg photodegradation using DOM samples with varying oxidation states and origins as well as organic ligands with known molecular structures. All DOM and organic ligands increased MeHg photodegradation under solar irradiation, but the first-order rate constants varied depending on the oxidation state of DOM and the type and concentration of the ligands. Compounds containing both thiols and aromatics (e.g., thiosalicylate and reduced DOM) increased MeHg degradation rates far greater than those containing only aromatic or thiol functional groups (e.g., salicylate or glutathione). Our results suggest that, among other factors, the synergistic effects of thiolate and aromatic moieties in DOM greatly enhance MeHg photodegradation.

  19. Variability of neuropathologic lesions in experimental methylmercurial encephalopathy in primates.

    PubMed Central

    Shaw, C. M.; Mottet, N. K.; Body, R. L.; Luschei, E. S.

    1975-01-01

    Acute and chronic intoxications of rhesus monkeys with methylmercury produced lesions in the central nervous system (CNS) with different distributions. Neuronal degeneration and astroglial proliferation predominated in the dentate nucleus, lateral geniculate nucleus, thalamus and pontine nuclei in 2 monkeys that received 2 mg/kg/day for 17 and 18 days, whereas pseudolaminar necrosis and astroglial proliferation were observed in the cerebral crotex, maximally in the calcarine and insular regions, in 4 monkeys that received 0.5 to 0.8 mg/kg/day for 3 to 8.5 months. Mercury concentrations in the CNS were much higher in the acutely intoxicated animals than in the chronically intoxicated animals, but the correlation between concentrations of mercury and the histologic destruction was not precise. Images Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 1 Figure 2 Figure 3 Figure 4 PMID:821350

  20. Efficiency of staining hair with indocyanine green

    NASA Astrophysics Data System (ADS)

    Kulyabina, Tatyana V.; Kochubey, Vyacheslav I.

    2005-06-01

    The efficiency of staining hair with indocyanine green (ICG) solution depending on type of hair, natural color, staining time and other parameters was investigated. Bonding ICG with hair material occurs due to interaction between ICG molecules and keratinocyte albumin. The penetration of ICG dye into hair meets with difficulties owing to surface protective layer.