Trace element analysis of three tissues from Eurasian otters (Lutra lutra) in South Korea.

Kang, Sukmo,Kang, Jung-Hoon,Kim, Soohee,Lee, Seung Heon,Lee, Seungwoo,Yu, Hee Jeong,Oh, Su-Jun,Park, Jung-Duck,Nam, Ki-Hoan,Han, Sung Yong,Lim, Jong-Deock,Ryu, Doug-Young Chapman Hall ; Kluwer Academic Publishers 2015 Ecotoxicology Vol.24 No.5

<P>Eurasian otters (Lutra lutra) are endangered worldwide, but the specific cause of their decline has not been determined. This study analyzed the concentrations of potentially toxic trace elements, including As, Cd, Pb, Hg, Se, Cu, Mn, and Zn, in the liver, kidney, and lung tissues of Eurasian otters in South Korea. There were high individual variations in the tissue concentrations of all the elements analyzed. The kidneys had the highest concentrations of Cd and Se among the three tissue groups, and the livers had the highest concentrations of Cu, Mn, Zn, and Hg. The Pb and As concentrations in the livers were not significantly different from those in the kidneys, and the lungs had the lowest concentrations of all the elements analyzed. The age-related bioaccumulation of Cd and Hg was evident in the three tissue groups, and of Se in the kidneys. The Pb concentration was higher in the livers of juveniles compared with those of adults and the Zn concentration was higher in the lungs of juveniles. There were no apparent gender differences in the concentrations of the elements analyzed among the tissue groups. The Se concentration correlated with the Hg concentration in the livers and kidneys, and with the Cd concentration in the kidneys. The Hg and Cd levels correlated in the three tissue groups. The Cu and Zn levels also correlated in the livers and kidneys. In general, the element concentrations were within the ranges reported by previous studies of this species from European countries, except for Cd and Hg, the levels of which were mostly lower than those reported previously. These findings may provide baseline information to facilitate the conservation of the Eurasian otter. To the best of our knowledge, this is the first available study of trace element concentrations in the tissues of Eurasian otters from South Korea or Asian countries.</P>

Evaluation and selection of reference genes for ecotoxicogenomic study of the green alga Closterium ehrenbergii using quantitative real-time PCR.

Lee, Min-Ah,Guo, Ruoyu,Ebenezer, Vinitha,Ki, Jang-Seu Chapman Hall ; Kluwer Academic Publishers 2015 Ecotoxicology Vol.24 No.4

<P>The green alga Closterium ehrenbergii occurs in fresh water environments and has been suggested as a model for ecotoxicological assessment. Quantitative real-time PCR (qRT-PCR), with its high sensitivity and specificity, is a preferred method for reliable quantification of gene expression levels. qRT-PCR requires reference genes to normalize the transcription level of the target gene, and selection of appropriate references is crucial. Here, we evaluated nine housekeeping genes, that is, 18S rRNA, ACT, TUA, TUB, eIF, H4, UBQ, rps4, and GAPDH, using 34 RNA samples of C. ehrenbergii cultured in various environments (e.g. exposure to heat shock, UV, metals, and non-metallic chemicals). Each housekeeping gene tested displayed different ranges of C T values for each experimental condition. The gene stability was determined using the descriptive statistic software geNorm, which showed that ACT, H4, and TUA were the most suitable reference genes for all the conditions tested. In addition, at least three genes were required for proper normalization. With these references, we assessed the expression level of the heat shock protein 70 (HSP70) gene in C. ehrenbergii cells exposed to thermal and toxic contaminant stress and found that it was significantly up-regulated by these stressors. This study provides potential reference genes for gene expression studies on C. ehrenbergii with qRT-PCR.</P>

Determination of mRNA expression of DMRT93B, vitellogenin, and cuticle 12 in Daphnia magna and their biomarker potential for endocrine disruption.

Kim, Jungkon,Kim, Younghee,Lee, Sangwoo,Kwak, Kyunghee,Chung, Wook-Jin,Choi, Kyungho Chapman Hall ; Kluwer Academic Publishers 2011 Ecotoxicology Vol.20 No.8

<P>We explored the use of molecular genetic biomarkers for endocrine disruption in Daphnia magna after the exposure to fenoxycarb (FOC), a model juvenile hormone analog. For this purpose, the mRNA expression patterns of DMRT93B (DMRT, sex determination), cuticle 12 (CUT, molting), and vitellogenin (VTG, embryo development) were determined in D. magna. Furthermore, these results were compared with developmental abnormality and reproduction performance. The fold changes of CUT and VTG mRNA expression showed significant dose-response relationship with FOC exposure. Relative mRNA expressions of DMRT and CUT showed notable changes at as low as 1 ng/l FOC. After chronic exposure FOC significantly delayed the first day of reproduction and decreased the number of young and growth rate even at 10 ng/l FOC. A concentration-dependant trend in reproduction effect was also observed. Developmental abnormality such as poorly developed second antennae and curved or unextended shell spines were observed. These results suggest that the three mRNAs, i.e., DMRT, CUT, and VTG can be used as biomarkers of endocrine disrupting effects in D. magna.</P>

Differential transcription of heat shock protein 90 (HSP90) in the dinoflagellate Prorocentrum minimum by copper and endocrine-disrupting chemicals.

Guo, Ruoyu,Ki, Jang-Seu Chapman Hall ; Kluwer Academic Publishers 2012 Ecotoxicology Vol.21 No.5

<P>The dinoflagellate algae survive variations in water temperature as well as sudden exposures to toxic substances; heat shock proteins (HSPs) seem to function as part of their cell survival strategy. In the present study, we determined the complete open reading frame (ORF) of HSP90 gene in the dinoflagellate Prorocentrum minimum (PmHSP90), and examined the expression levels of the gene after exposure to thermal stressors, copper metal, and endocrine-disrupting chemicals, including bisphenol A (BPA) and polychlorinated biphenyl (PCB). The complete ORF of PmHSP90 was 2,130-bp long, encoding a 709-amino acid-long polypeptide (81.62?kDa), and bearing characteristics of the HSP90 family and conserved domains. Real-time (RT)-PCR analyses revealed different expression patterns after exposure to heat, metals, and chemicals. The expression of PmHSP90 was significantly upregulated by increased thermal stresses, with the highest changes of 2.4-fold and 1.9-fold occurring after 24?h at 25?C and 30?C, respectively. The gene expression dramatically increased (2.1 to 8.9-fold changes) with increasing concentrations of copper (one-way ANOVA, P?<?0.01). Treatment with BPA or PCB, however, did not induce significant changes in PmHSP90 expression. These data suggest that the dinoflagellate HSP90 responds to thermal stressors, but may differentially respond to toxic substances such as metals and endocrine-disrupting chemicals.</P>

Trace element contamination in nestling black-tailed gulls (Larus crassirostris) in Korea.

Kim, Jungsoo,Oh, Jong-Min Chapman Hall ; Kluwer Academic Publishers 2015 Ecotoxicology Vol.24 No.4

<P>At Hongdo Island, Gyeongsangnam-do, Korea, a breeding site of black-tailed gull (Larus crassirostris), we collected nestlings from two locations: a 'reference' site (n?=?10) with no known source of lead contamination and 'lighthouse' site (n?=?10) with suspected lead contamination from leaded paint. Iron concentrations in the kidney and bone, manganese in the muscle, copper in the bone, lead in the muscle and bone, and cadmium in the liver, muscle, and bone at the reference site were significantly higher than at the lighthouse. Manganese concentrations in the liver and kidney, and lead in the kidney were significantly greater at the lighthouse than at the reference site. Iron, zinc, manganese, copper, lead and cadmium concentrations had tissue-specific accumulation at both sites. Lead concentrations in 10?% of livers and in 80?% of kidneys at the lighthouse, and in 20?% of livers from the reference were within a range considered toxic (>6.00?μg/g?dw in the liver and kidney). Lead concentrations in 50?% of black-tailed gull nestlings at the reference and 80?% nestlings at the lighthouse were greater in livers than in bones, which is suggestive of acute lead exposure. For cadmium, all liver and kidney concentrations from two sites were at a level considered background in birds. Cadmium concentrations of every sample were higher in kidneys than in livers, suggestive of chronic cadmium exposure. Lead concentrations in gull nestlings in the present study were relatively higher than other gull species worldwide, but cadmium concentrations were relatively lower.</P>

Trace element concentrations in eggshells and egg contents of black-tailed gull (Larus crassirostris) from Korea.

Kim, Jungsoo,Oh, Jong-Min Chapman Hall ; Kluwer Academic Publishers 2014 Ecotoxicology Vol.23 No.7

<P>Concentrations of trace elements (cadmium, lead, copper, manganese and zinc) were examined in eggs of black-tailed gulls (Larus crassirostris) from Hongdo Island, Korea to determine the difference and distribution of trace elements in eggshells and egg contents. Cadmium, lead and manganese concentrations were greater in eggshells than in egg contents. In contrast, zinc concentrations were higher in egg contents than in eggshells. Trace element concentrations followed the order: zinc > lead = manganese = copper > cadmium (eggshells) and zinc > copper > manganese > lead > cadmium (egg contents). Cadmium concentrations were relatively low (<1 μg/g dw) in egg contents and eggshells. Concentrations of cadmium, lead and copper were significantly correlated between egg contents and eggshells. This indicates that cadmium, lead and copper levels in the eggshell can reflect their levels in the egg contents. There was also a high ratio (3.2) of eggshell/egg content for lead. These results indicate that the eggshell might be useful as a bio-indicator for monitoring cadmium, lead and copper in the egg content.</P>

Effect of the environmental quality and food chain on trace element concentrations in Heron and Egret chicks at Pyeongtaek colony, Korea.

Kim, Jungsoo,Oh, Jong-Min Chapman Hall ; Kluwer Academic Publishers 2014 Ecotoxicology Vol.23 No.7

<P>Trace element concentrations in the diet can affect the levels in birds. Heron and egret chicks have been recommended as useful biological indicators for monitoring trace element contamination in the aquatic ecosystem. Iron, zinc, manganese, copper, lead and cadmium concentrations were measured in the livers and stomach contents of Grey Heron (Ardea cinerea), Intermediate Egret (Egretta intermedia), Little Egret (Egretta garzetta) and Black-crowned Night Heron (Nycticorax nycticorax) chicks from Pyeongtaek colony, Korea in 2008. Iron, zinc, manganese, copper and cadmium concentrations in livers differed among four heron and egret species. Stomach content concentrations of iron, zinc, copper, lead and cadmium concentrations differed among the four species. Essential elements such as iron, zinc, manganese and copper concentrations were within the range of other heron and egret studies and these levels may be regulated by a normal homeostatic mechanism. Two of 11 (18.2%) Grey Heron and two of 10 (20.0%) Black-crowned Night Heron chicks exceeded the background lead level (<6 ?g/g dw) for birds and were at a level considered lead exposed (6-30 ?g/g dw). Cadmium concentrations did not exceed the background levels for wild birds. In livers of combined heron and egret chicks, lead, but not cadmium concentrations were associated with concentrations in the stomach contents. These results suggest that lead concentrations in chicks can reflect qualities of feeding area such as streams, rivers and paddy fields and chicks represent a bioindicator to evaluate lead contamination in aquatic ecosystems.</P>

Tuning anti-microbial activity of poly(4-vinyl 2-hydroxyethyl pyridinium) chloride by anion exchange reactions.

Sharma, Sunil K,Chauhan, Ghanshyam S,Gupta, Reena,Ahn, J-H Chapman and Hall ; Kluwer Academic Publishers 2010 Journal of materials science, Materials in medicin Vol.21 No.2

<P>A series of new bioactive polymers with pendant choline analogous group was prepared by anion exchange reaction direct at the quaternary nitrogen of the polycation. Poly(4-vinyl 2-hydroxyethyl pyridinium) chloride was prepared in situ by simultaneous polymerization and quaternization of 4-vinyl pyridine with 2-chloroethanol that also acts as catalyst. The counter anion (Cl(-)) of the polycation was exchanged by anion exchange reaction with Br(-), (-)OH, (-)SH, NO(3) (-), BF(4) (-) or CF(3)COO(-). Evidence of anion exchange was obtained by the characterization of the resultant polymers. The nature of the counter anion has profound effect on their properties including strong anion-dependent anti-microbial activity against bacteria and fungus. Polymer containing (-)OH was observed to be the most potent anti-microbial agent with the lowest minimum inhibitory concentration against both the classes of microbes studied.</P>

Effect of protein concentrations of bovine serum albumin and 관-globulin on the frictional response of a cobalt-chromium femoral head.

Duong, Cong-Truyen,Lee, Jae-Hoon,Cho, Younho,Nam, Ju-Suk,Kim, Hyong-Nyun,Lee, Sang-Soo,Park, Seonghun Chapman and Hall ; Kluwer Academic Publishers 2012 Journal of materials science, Materials in medicin Vol.23 No.5

<P>The study aims to identify the concentration-dependent role of bovine serum albumin (BSA) and 관-globulin in the lubricating ability of a cobalt-chromium femoral head. The frictional coefficients of the cobalt-chromium femoral head decreased with increasing BSA concentrations from 10 to 40 mg/ml and showed statistical differences between any of the BSA concentration groups, except between the 30 and 40 mg/ml concentration groups. In 관-globulin, the frictional coefficients significantly decreased at concentrations of 2.5 and 5.0 mg/ml as compared with the PBS control group, but significant increases were observed at 7.5 and 12.5 mg/ml. These results suggest that the friction of the cobalt-chromium femoral head is dependent on the concentration of both BSA and 관-globulin. However, there is a maximum concentration for BSA to act as an effective boundary lubricant, while the lubricating ability of 관-globulin is most effective in the physiological concentration range within human synovial fluid.</P>

Preparation and characterization of electrospun PCL/PLGA membranes and chitosan/gelatin hydrogels for skin bioengineering applications.

Franco, Rose Ann,Nguyen, Thi Hiep,Lee, Byong-Taek Chapman and Hall ; Kluwer Academic Publishers 2011 Journal of materials science, Materials in medicin Vol.22 No.10

<P>In this study, two distinct systems of biomaterials were fabricated and their potential use as a bilayer scaffold (BS) for skin bioengineering applications was assessed. The initial biomaterial was a polycaprolactone/poly(lacto-co-glycolic acid) (PCL/PLGA) membrane fabricated using the electrospinning method. The PCL/PLGA membrane M-12 (12% PCL/10% PLGA, 80:20) displayed strong mechanical properties (stress/strain values of 3.01??0.23?MPa/225.39??7.63%) and good biocompatibility as demonstrated by adhesion of keratinocyte cells on the surface and ability to support cell proliferation. The second biomaterial was a hydrogel composed of 2% chitosan and 15% gelatin (50:50) crosslinked with 5% glutaraldehyde. The CG-3.5 hydrogel (with 3.5% glutaraldehyde (v/v)) displayed a high porosity, 97%, good compressive strength (2.23??0.25?MPa), ability to swell more than 500% of its dry weight and was able to support fibroblast cell proliferation. A BS was fabricated by underlaying the membrane and hydrogel casting method to combine these two materials. The physical properties and biocompatibility were preliminarily investigated and the properties of the two biomaterials were shown to be complementary when combined. The upper layer membrane provided mechanical support in the scaffold and reduced the degradation rate of the hydrogel layer. Cell viability was similar to that in the hydrogel layer which suggests that addition of the membrane layer did not affect the biocompatibility.</P>