bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel ATR‐FTIR method for functionalised surface characterisation
Authors: Andersson Per Ola , Lind Per , Mattsson Andreas , Österlund Lars 
Published: January 2008

AbstractWe demonstrate a novel method to analyse ex situ prepared chips by attenuated total reflection Fourier transform infrared spectroscopy (ATR‐FTIR), which circumvents tedious functionalisation steps of internal reflection elements (IREs), and simultaneously allows for complementary measurements by other analytical techniques. This concept is proved by utilising immobilised metal affinity capture (IMAC) chips containing about 10 µm thick films of copolymers coated with nitrilotriacetic acid (NTA) groups. With this so‐called ‘upside‐down’ ATR‐FTIR technique, each chemical modification step can be followed and optimised with respect to concentration, buffer, pH, ionic strength, and so on, and there are no limitations in variations or numbers of functionalised surfaces that can be generated. We have demonstrated the feasibility of this approach to determine the molecular structure of ligand bonded to immobilised polypeptide, directly observed in the raw ATR‐FTIR spectrum. Peptide adsorption in a thick NTA–copolymer matrix yields a high peptide concentration as determined by the analysis of the Langmuir adsorption isotherm. Combined with the ‘upside‐down’ ATR‐FTIR approach which samples the outermost region of the exposed NTA–copolymer film, this generates well‐resolved amide I and II absorption bands that reduce the necessity of using D2O based buffers, which otherwise is common in mid‐IR spectroscopy of proteins. We believe that this new optical surface characterisation method has a great potential as a stand‐alone or complementary analytical tool. We emphasise further that with this approach no chemical treatment of IREs is needed; the chips can be regenerated and reused, and analysed by complementary analytical techniques such as mass spectrometry. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of different primary ion species on the secondary ion emission from PNA/DNA biosensor surfaces
Authors: Hellweg Sebastian , Heile Andreas , Grehl Thomas , Arlinghaus Heinrich F. 
Published: January 2008

AbstractIn recent publications, the use of time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) for a detailed examination of the immobilization process of peptide nucleic acid (PNA) and its hybridization capability to label‐free complementary DNA fragments has been described. Unlabeled single‐stranded DNA was hybridized to biosensor surfaces containing both complementary and noncomplementary PNA sequences. The hybridization of complementary DNA could readily be identified by detecting phosphate‐related molecules from the DNA backbone such as PO3−.Extending previous measurements on hybridized DNA surfaces using different primary ions and energies, additional ion species have been applied for a more detailed evaluation of the secondary ion emission behavior under static SIMS conditions. The large number of available primary ion species allowed for a comparison between results achieved with ‘classic’ monoatomic and polyatomic ions (such as Ar+, Ga+, Xe+ and SF5+) and bismuth primary ions up to cluster sizes of seven constituents. It was found that the use of polyatomic primary ions in general resulted in a significant increase of secondary ion yields and secondary ion formation efficiencies of DNA‐specific fragments, while the highest values could be achieved with large bismuth cluster ions. It can also be shown that nonlinear effects in projectile‐surface‐excitation are partly responsible for the observed enhancements of yield and efficiency under polyatomic bombardment.It can be concluded that large bismuth cluster ions are the best choice for detecting hybridized DNA on PNA biosensor chips. Their application optimizes analysis conditions under which TOF‐SIMS provides a useful method for label‐free DNA diagnostics. Copyright © 2008 John Wiley & Sons, Ltd.
Graft photopolymerization of polyethylene glycol monoacrylate (PEGA) on poly(methyl methacrylate) (PMMA) films to prevent BSA adsorption
Authors: Iguerb O. , Bertrand P. 
Published: January 2008

AbstractThis work aims at developing antifouling surfaces. For that purpose, poly(methyl methacrylate) (PMMA) films are surface‐modified by grafting a solution spin‐coated macromonomer, polyethylene glycol monoacrylate (PEGA) under UV irradiation in ambient air. Benzophenone is used as photosensitizer to generate polymer radicals at the surface of the PMMA film. This graft polymerization is carried out onto PMMA substrates pretreated by wet oxidation, with different PEGA formulations. The photografting of PEGA solution is evidenced by Time‐of Flight (ToF)‐SIMS and XPS. Both techniques clearly proved that PEGA is grafted onto preoxidized PMMA substrates. The effect of macromonomer concentration on extent of grafting is investigated. It was found that the amount of grafted PEGA increases by increasing PEGA concentration. Inhibition of protein adhesion by the modified PMMA surfaces is evaluated by XPS and ToF‐SIMS, using, bovine serum albumin (BSA) as model protein. The photografted PMMAox surfaces exhibit excellent protein repellence for high PEGA concentration. Copyright © 2008 John Wiley & Sons, Ltd.
Cytotoxic effects induced by hexachlorobenzene in Squilla mantis (L.) (Crustacea, Stomatopoda)
Authors: Dell'Anno Antonio , Raffaelli Francesca , Danovaro Roberto , Nanetti Laura , Vignini Arianna , Moroni Cinzia , Mazzanti Laura 
Published: January 2008

AbstractContamination of marine environments by hexachlorobenzene (HCB) represents a serious concern for potential consequences on ecosystem and human health. Despite this, information on cytotoxic effects on marine organisms is still largely lacking. In this study, we investigated cytotoxic effects induced by HCB on gonads and muscular tissue of Squilla mantis by analysing Na+/K+‐ATPase activity and plasma membrane fluidity. This crustacean species was selected as a model for its habitat, trophic level, feeding behavior, and commercial exploitation for human consumption. Time course experiments revealed that low concentrations of HCB (i.e. 50 nM) determine an exponentially decrease of Na+/K+‐ATPase activity and a significant modification of cellular membrane fluidity. Significant negative relationships between Na+/K+‐ATPase activity and membrane fluidity were observed, suggesting that changes in the structure and packing of cellular membranes induced by HCB may be the primary factor affecting the activity of essential bilayer‐associated enzymes. Overall these findings suggest that even small concentrations of HCB may determine important changes on cell metabolism with potential cascade effects on recruitment of this commercial species. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Protective effect of green tea polyphenols on tributyltin‐induced oxidative damage detected by in vivo and in vitro models
Authors: Liu Huigang , Guo Zonglou , Xu Lihong , Hsu Stephen 
Published: January 2008

AbstractThe current study investigated the protective effects of green tea polyphenols (GTPP) on TBT‐induced oxidative damage. The results showed that reactive oxygen species (ROS) production and malondialdehyde content of the liver in mice exposed to TBT were reduced in the GTPP‐treated group compared to the untreated group. The intracellular ROS level was elevated in TBT‐treated human FL cells in a time‐dependent manner. Comet assay data demonstrated that the number of cells with damaged DNA in untreated mice was found to be significantly higher compared to GTPP‐treated mice. Damage to the nuclei and mitochondria observed in TBT‐treated mice were alleviated in mice treated with both TBT and GTPP. The results represent the first observation that GTPP were effective in reducing TBT‐induced oxidative damage both in vivo and in vitro. The possible protective mechanism may be due to the powerful ability of GTPP to scavenge ROS and prevent DNA breaks. We conclude that GTPP could be an effective agent or food supplement to reduce the cytotoxicity of TBT. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Physiological responses of Matricaria chamomilla to cadmium and copper excess
Authors: Kováčik Jozef , Bačkor Martin , Kaduková Jana 
Published: January 2008

AbstractPhysiological responses of Matricaria chamomilla plants exposed to cadmium (Cd) and copper (Cu) excess (3, 60, and 120 μM for 7 days) with special emphasis on phenolic metabolism were studied. Cu at 120 μM reduced chamomile growth, especially in the roots where it was more abundant than Cd. Notwithstanding the low leaf Cu amount (37.5 μg g−1 DW) in comparison with Cd (237.8 μg g−1 DW) at 120 μM, it caused reduction of biomass accumulation, Fv/Fm ratio and soluble proteins. In combination with high accumulation of phenolics, strong reduction of proteins and high GPX activity in the roots, this supports severe redox Cu properties. In terms of leaf phenylalanine ammonia‐lyase (PAL) activity, it seems that Cd had a stimulatory effect during the course of the experiment, whereas Cu was found to stimulate it after 7‐day exposure. The opposite trend was visible in the roots, where Cd had a stimulatory effect at high doses but Cu mainly at the highest dose. This supports the assumption of different PAL time dynamics under Cd and Cu excess. A dose of 60 and 120 μM Cu led to 2‐ and 3‐times higher root lignin accumulation while the same Cd doses increased it by 33 and 68%, respectively. A Cu dose of 120 μM can be considered as limiting for chamomile growth under conditions of present research, while resistance to high Cd doses was confirmed. However, PAL and phenolics seemed to play an important role in detoxification of Cd‐ and Cu‐induced oxidative stress. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Acute effects of microcystins on the transcription of antioxidant enzyme genes in crucian carp Carassius auratus
Authors: Sun Yuhua , Tang Rong , Li Dapeng , Zhang Xuzhen , Fu Juan , Xie Ping 
Published: January 2008

AbstractRecent evidences suggested that oxidative stress may play a significant role in the pathogenesis of MCs toxicity. In the present study, the acute effects of microcystins on the transcription of antioxidant enzyme genes were investigated in liver of crucian carp i.p.‐injected with 50 μg MC‐LReq per kg body weight (BW). We reported the cDNA sequences for four kinds of antioxidant enzyme (GSH‐PX, CAT, Cu/Zn SOD, and GR) genes, and evaluated the oxidant stress induced by MCs through analyzing the transcription abundance of antioxidant enzyme genes using real‐time PCR method. The time‐dependent change of relative transcription abundance and expression of the antioxidant enzyme genes were determined at 1, 3, 12, 24, and 48 h. The transcription abundance varied among antioxidant enzymes, with GSH‐PX and GR down‐regulation, and CAT and SOD significantly upregulation. Based on these data, we tentatively concluded that the oxidant stress was induced by MCs, and caused the different response of the antioxidant enzyme genes. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Organochlorine residues in the blubber and liver of bottlenose dolphins (Tursiops truncatus) stranded in the Canary Islands, North Atlantic Ocean
Authors: Carballo Matilde , Arbelo Manuel , Esperón Fernado , Mendez Mariña , de la Torre Ana , Muñoz Maria Jesus 
Published: January 2008

AbstractPolychlorinated biphenyls (PCBs) and chlorinated pesticides: dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordanes (CHLs), dieldrin, and hexaclorobenzene (HCB) were detected in the blubber and liver of 11 bottlenose dolphins (Tursiops truncatus) from the Canary Islands (North Atlantic Ocean). Samples were obtained from stranded dolphins over the period 1997–2005. Among the organochlorines analyzed, PCBs and DDTs were predominant in the two tissues, followed in decreasing order by chlordane, trans‐nonachlor > cis‐nonachlor > dieldrin and HCB. The sum 11 PCBs in the blubber ranged between 301 and 33,212 ng g−1 ww (990 and 136,679 ng g−1 lw). Highly chlorinated PCBs such us CB153, CB180, and CB138 were the prominent congeners, accounting for 51% of the total PCBs. The sum DDT concentration in the blubber ranged between 147 and 21,050 ng g−1 ww. (490–105,250 ng g−1 lw) The main DDT metabolite was p,p′‐DDE, representing 83% of DDTs in the blubber. In general, the levels of PCBs and DDTs detected were similar to those found in bottlenose dolphins in the North of Europe. The 2,3,7,8‐TCDD toxic equivalent (TEQ) in blubber and liver was calculated for the toxicity assessment of mono‐ortho substituted PCBs congeners (CB105, CB118, CB156). It is important to mention that TEQ values and p,p′‐DDE concentration in adult male specimens are approaching the levels associated with adverse effects found in marine mammals. The information provided represents the first tissue loads of organochlorine compounds in small cetaceans from this area. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Dechlorination with sodium thiosulfate affects the toxicity of wastewater contaminated with copper, cadmium, nickel, or zinc
Authors: Oh So‐Rin , Kim Jung‐Kon , Lee Min‐Jung , Choi Kyungho 
Published: January 2008

AbstractSodium thiosulfate is recommended by U.S. Environmental Protection Agency for dechlorination of the effluent samples containing residual chlorines before the toxicity testing. For samples contaminated with residual chlorine and metals, e.g., Cd(II), Cu(II) and Ni(II); however, metal toxicity as measured with Daphnia magna was reduced even at approximately half the recommended amount of sodium thiosulfate. Formation of metal‐thiosulfate complexes that are less bioavailable may explain the apparent reduction of metal toxicity. In contrast, for samples spiked with Zn(II), dechlorination with sodium thiosulfate increased toxicity. The use of sodium thiosulfate for dechlorination should be cautioned when the sample under the bioassay is potentially contaminated with metals. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Effects of the insecticides malathion and diazinon on the early oogenesis in mice in vitro
Authors: Bonilla Edmundo , Hernández Fidel , Cortés Leticia , Mendoza Miriam , Mejía Joel , Carrillo Edgar , Casas Eduardo , Betancourt Miguel 
Published: January 2008

AbstractMalathion and diazinon are two of the most commonly used organophosphorous (OP) agrochemicals. Several studies show that these pesticides exert several effects on mammalian spermatogenesis. Nevertheless, there are no studies concerning their effects on oogenesis. The objective of this study was to evaluate the effects of these insecticides on the viability of in vitro cultured mouse oocytes during the early oogenesis and to get a further understanding of the molecular mechanisms by which OP insecticides act and affect germinal cells. Oocytes were cultured from fetal ovaries for 10 days, when most oocytes had reached the diplotene stage (germinal vesicle stage). Cultures were exposed to different concentrations of malathion or diazinon for 24 h, and the effect on oocyte viability was assessed. Gene expression in oocytes exposed to the insecticides was analyzed by generating cDNA libraries and performing differential screenings. Results show a significant decrease in oocytes survival after 24‐h exposure to 250 μM malathion or 900 nM diazinon, and the effect of these insecticides on the regulation of genes encoding proteins involved in transcription (BP75), translation (ribosomal protein S5), and mitochondrial function (cytochrome oxidase subunits I and III), providing evidence for OP insecticides as toxicants for mammals oocytes during the early oogenesis. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
cDNA cloning and expression of a xenobiotic metabolizing cytochrome P4501A (CYP1A) from the yellow catfish, Pelteobagrus fulvidraco (Siluriformes)
Authors: Kim Jin‐Hyoung , Hwang Dae‐Sik , Son Kyu‐Hee , Raisuddin Sheikh , Ki Jang‐Seu , Lee Jae‐Seong , Han Kyung‐Nam 
Published: January 2008

AbstractWe cloned the full‐length cDNA sequence of xenobiotic metabolizing cytochrome P4501A (CYP1A) gene from the yellow catfish (Pelteobagrus fulvidraco, Siluriformes, Bagridae). P. fulvidraco is a commercially important fish generally distributed in Southeast Asian countries and Korea. This is the first report of any xenobiotic metabolizing gene from this fish species. Tissue distribution of CYP1A was studied by real‐time PCR. Induction pattern of CYP1A was studied by exposing fish to β‐naphthoflavone (BNF). Liver showed the highest level of expression in control as well as BNF‐treated fish. However, high levels of expression were also recorded in brain, intestine, and kidney and the least in the muscles. Information on CYP genes in fish from order Siluriformes is limited as compared with other fish orders. This study provides an insight into the xenobiotic metabolizing system of P. fulvidraco and offers baseline information for further research related to biomarker use of CYP1A and detoxification strategies of this commercially important fish species. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Risk assessment of herbicide mixtures in a large European lake
Authors: Chèvre Nathalie , Edder Patrick , Ortelli Didier , Tatti Elisa , Erkman Suren , Rapin François 
Published: January 2008

AbstractLake Geneva is one of the largest European lakes with a surface area of 580 km2. Its catchment area covers 7400 km2, of which ∼20% is arable land. Monitoring campaigns have been carried out in 2004 and 2005 to determine the contamination of the lake by pesticides. The results highlight the widespread presence of herbicides in water, the measured concentrations for most substances remaining constant in 2004 and 2005. However, for some individual herbicides the concentrations increased drastically (e.g., the herbicide foramsulfuron). We assessed the environmental risk of the herbicides detected in the lake using water quality criteria recently determined for the Swiss environmental protection agency. Furthermore, we assessed the risk of herbicide mixtures, grouped based upon their mode of action. Generally, the risk estimated for all single substances is low, except for some sulfonylurea compounds. For these substances, the measured concentrations are higher than the predicted no‐effect concentration. Impact on the flora of the lake can therefore not be excluded. When mixtures of pesticides with similar mode of action are taken into account, the risk remains lower than the mixture water quality criteria for all groups, but can reach as high as one third of this quality criteria. A further step would therefore be to assess the risk of the total pesticide mixture, including similar and dissimilar modes of action. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Disruption effects of monophthalate exposures on inter‐Sertoli tight junction in a two‐compartment culture model
Authors: Zhang Yun‐Hui , Lin Ling , Liu Zhi‐Wei , Jiang Xue‐Zhi , Chen Bing‐Heng 
Published: January 2008

AbstractPhthalates are suspect environmental endocrine disruptors that may affect male reproduction and development by disturbing androgen synthesis and cell–cell interactions in the seminiferous epithelium. The in vivo metabolites, monophthalates, are thought to be the active agents, and toxicant effects including testicular damage and decreased sperm motility have been described previously. In this study, the aim was to investigate the effect of monophthalates on Sertoli cells using a two‐compartment cell culture model, asking whether tight junction protein structures are affected, compromising the blood‐testis barrier and contributing to male‐mediated toxicity. Sertoli cells were isolated from Sprague Dawley rat testes and seeded onto the filters of two‐compartment wells. A Sertoli cell monolayer was allowed to form, whereupon the cultures were treated with 0, 10, 30, 150, and 600 μmol/L monobutyl phthalate (MBP) or mono‐2‐ethylhexyl phthalate (MEHP) for 24 h. Effects on the tight junctions between adjacent Sertoli cells were studied by light and transmission electron microscopy, the transepithelial electrical resistance (TEER) assay, and immunofluorescence localization. Results showed that exposures to monophthalates destroyed tight junctional structure in Sertoli cell monolayers in a dose‐depended manner, as evidenced by a loss of single‐cell layer organization in the cultures, decline of TEER value, and decreased expression of proteins associated with tight junctions such as zonula occludens‐1 (ZO‐1), F‐actin, and Occludin. The changes were observed at doses of 150 and 600 μmol/L, which is 10–100 times higher relative to estimated human exposures from the environment. These results are consistent with monophthalate‐induced damage to tight junctions between adjacent Sertoli cells, suggesting that damage to Sertoli cell tight junctions induced by monophthalates may be an underlying mechanism of their male‐mediated reproductive toxicity. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
Chronic nickel‐induced DNA damage and cell death: The protection role of ascorbic acid
Authors: Jia Jie , Chen Jie 
Published: January 2008

AbstractHigh consumption of nickel‐containing products leads to more exposure of humans to nickel and its by‐products. Except the lethal effect of acute nickel poison, chronic nickel exposure is also harmful to humans, but the mechanism of chronic nickel‐induced cytotoxicity remains unclear. Here, we found that long‐term exposure of Ni2+ led to significant DNA fragmentation, cell death, and reactive oxygen species (ROS) generation in human leukemia HL‐60 cells. Induction of Ni2+ on DNA fragmentation and cell death could be prevented by the antioxidants ascorbic acid (ASA) or N‐acetyl‐cysteine (NAC), or enhanced by H2O2, indicating the involvement of ROS generation in the chronic nickel cytotoxicity in cells. Long‐term exposure of mice to low Ni2+ also led to a significant increase in both the ROS generation in the serum and the DNA fragmentation in the peripheral blood mononuclear cells (PBMC), while coadministration of ASA with Ni2+ together significantly decreased both the DNA fragmentation and the ROS generation. Collectively, these results proved that ROS generation is at least one mechanism of the cytotoxicity of chronic nickel exposure, while ASA is probably useful for people to prevent the chronic nickel cytotoxicity, especially for those who work or live near a mining area or a factory related with nickel. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.