bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal and metabolic factors affecting bioaccumulation of triazine herbicides by rainbow trout (Oncorhynchus mykiss)
Authors: Tarja Nakari , Kirsti Erkomaa , Marja Luotola , Kari Ennola 
Published: July 2003

AbstractThe bioaccumulation of the triazine herbicides terbutryn and terbuthylazine in rainbow trout was investigated at water temperatures of 4°C, 10°C, and 17°C. The synergetic effect of water temperature and herbicide on fish liver detoxification metabolism was also studied by measuring liver ethoxyresorufin‐O‐deethylase (EROD) and UDP‐glucuronosyltransferase (UDPGT) activities. The bioaccumulation of terbutryn increased significantly with increasing water temperature. However, temperature seemed to have no effect on the bioaccumulation of terbuthylazine. Both chemicals decreased the measured enzyme activities. Also, temperature effects were significant. In all tests the highest liver EROD activities were measured in fish exposed to a water temperature of 4°C, and the activities decreased with increasing water temperature. The thermal effects on fish liver UDPGT activity differed between the herbicides. The highest activities at a water temperature of 4°C were measured in fish exposed to terbutryn, whereas fish exposed to terbuthylazine had the highest liver UDPGT activities at 17°C. Measuring liver detoxification metabolism together with bioaccumulation increases the understanding of bioaccumulation of chemicals in different environmental conditions. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 219–226, 2003.
Cylindrospermopsin‐induced protein synthesis inhibition and its dissociation from acute toxicity in mouse hepatocytes
Authors: Froscio Suzanne M. , Humpage Andrew R. , Burcham Philip C. , Falconer Ian R. 
Published: July 2003

AbstractThe toxicology of the cyanobacterial alkaloid cylindrospermopsin (CYN), a potent inhibitor of protein synthesis, appears complex and is not well understood. In exposed mice the liver is the main target for the toxic effects of CYN. In this study primary mouse hepatocyte cultures were used to investigate the mechanisms involved in CYN toxicity. The results show that 1–5 μM CYN caused significant concentration‐dependent cytotoxicity (52%–82% cell death) at 18 h. Protein synthesis inhibition was a sensitive, early indicator of cellular responses to CYN. Following removal of the toxin, the inhibition of protein synthesis could not be reversed, showing behavior similar to that of the irreversible inhibitor emetine. In contrast to the LDH leakage, protein synthesis was maximally inhibited by 0.5 μM CYN. No protein synthesis occurred over 4–18 h at or above this concentration. Inhibition of cytochrome P450 (CYP450) activity with 50 μM proadifen or 50 μM ketoconazole diminished the toxicity of CYN but not the effects on protein synthesis. These findings imply a dissociation of the two events and implicate the involvement of CYP450‐derived metabolites in the toxicity process, but not in the impairment of protein synthesis. Thus, the total abolition of protein synthesis may exaggerate the metabolite effects but cannot be considered a primary cause of cell death in hepatocytes over an acute time frame. In cell types deficient in CYP450 enzymes, protein synthesis inhibition may play a more crucial role in the development of cytotoxicity. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 243–251, 2003.
Acute toxicity and bioaccumulation of arsenic in tilapia (Oreochromis mossambicus) from a blackfoot disease area in Taiwan
Authors: Liao Chung‐Min , Chen Bo‐Ching , Singh Sher , Lin Ming‐Chao , Liu Chen‐Wuing , Han Bor‐Cheng 
Published: July 2003

AbstractThe general objective of our work was to determine the acute toxicity and bioaccumulation of arsenic (As) in tilapia (Oreochromis mossambicus) from the blackfoot disease (BFD) area in Taiwan. The average concentration of As in pond water ranged from 17.8 to 49 μg L−1. Acute toxicity tests showed that the As concentration that caused toxicity to tilapia ranged from 69 060 μg As L−1, in the 24‐h toxicity test, to 28 680 μg As L−1, in the 96‐h toxicity test. We measured As concentrations in various tissues of tilapia to identify the affinities of tissues for As. Significant correlations were found among the As concentrations in all tissues. The highest bioconcentration factor (BCF) was found in the intestine (maximum value: 2270). The order of BCFs was: intestine > stomach > liver ≃ gill > muscle. Arsenic concentrations in all tissues were allometric, negatively correlating with fish body weight [r2 = 0.63 ± 0.045 (mean ± SE), p < 0.05]. Our results also revealed that As concentrations in muscle tissue were positively correlated with As accumulation in the viscera (r2 = 0.85, p < 0.05). Significantly higher concentrations of As were obtained in the viscera of tilapia [12.65 ± 10.17 μg g−1 dry wt (mean ± SD)] than in the muscle tissue (3.55 ± 0.42 μg g−1 dry wt). Our results suggest that a simple way of reducing the health risk associated with consuming tilapia is to trim and cook the fish properly, that is, removing the viscera of tilapia can greatly reduce the amount of As ingested and consequently reduce the health risks. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 252–259, 2003.
Biochemical and histopathological effects of glyphosate herbicide on Nile tilapia (Oreochromis niloticus)
Authors: Jiraungkoorskul W. , Upatham E. S. , Kruatrachue M. , Sahaphong S. , Vichasri‐Grams S. , Pokethitiyook P. 
Published: July 2003

AbstractIn Oreochromis niloticus that had been exposed for 3 months to sublethal concentrations (5 and 15 ppm) of the commercial glyphosate herbicide (C3H8NO5P) Roundup, the organs exhibited varying degrees of histopathological change. In the gills filament cell proliferation, lamellar cell hyperplasia, lamellar fusion, epithelial lifting, and aneurysm were observed. In the liver there were vacuolation of hepatocytes and nuclear pyknosis. Kidney lesions consisted of dilation of Bowman's space and accumulation of hyaline droplets in the tubular epithelial cells. The structural damages could be correlated to the significant increase (p ≤ 0.05) in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities in the second and third months of exposure. The results indicated that long‐term exposure to glyphosate at sublethal concentrations had adverse effects on the histopathological and biochemical alterations of the fish. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 260–267, 2003.
Effect of chronic exposure to lead on estrogen action in the prepubertal rat uterus
Authors: Tchernitchin Nina N. , Clavero Andrea , Mena Miguel A. , Unda Cristina , Villagra Rebeca , Cumsille Miguel , Tchernitchin Andrei N. 
Published: July 2003

AbstractLead is a widely spread environmental pollutant known to affect both male and female reproductive systems in humans and in experimental animals. The present study investigated the effect of a chronic exposure to lead on different parameters of estrogen stimulation in the uteri of prepubertal rats. Chronic exposure to lead enhanced some parameters of estrogen stimulation, inhibited other estrogenic responses, while the remainder were unaltered. Estrogen‐induced uterine eosinophilia (24 h), the proportion of uterine eosinophils in the mesometrium (6 h), and luminal epithelial hypertrophy and RNA content (24 h) appeared to be enhanced by lead exposure, compared to lead‐unexposed control animals. Eosinophilia in the endometrium (6 h), the proportion of uterine eosinophils in the endometrium (6 and 24 h), edema in superficial and deep endometria (6 h), luminal epithelial hypertrophy (6 h), and mitotic response (cell proliferation) in all uterine cell types were inhibited by lead exposure, whereas circular myometrial hypertrophy was not significantly modified. The effects of lead exposure on responses to estrogen found in this study showed some differences with those previously reported for acute or subacute exposure to lead. The results revealed an interaction with the different mechanisms of estrogen action in the uterus at various levels, suggesting that some uterine cell types are more sensitive to lead than others. The relevance of the results for lead‐induced infertility is discussed in this article, and possible mechanisms of action are proposed. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 268–277, 2003.
Protective roles of mitochondrial manganese‐containing superoxide dismutase against various stresses in Candida albicans
Authors: Hwang Cheol‐Sang , Baek Yong‐Un , Yim Hyung‐Soon , Kang Sa‐Ouk 
Published: July 2003

AbstractCandida albicans contains copper‐ and zinc‐containing superoxide dismutase but also two manganese‐containing superoxide dismutases (MnSODs), one in the cytosol and the other in the mitochondria. Among these, the SOD2 gene encoding mitochondrial MnSOD was disrupted and overexpressed to investigate its roles in C. albicans. The null mutant lacking mitochondrial MnSOD was more sensitive than wild‐type cells to various stresses, such as redox‐cycling agents, heating, ethanol, high concentration of sodium or potassium and 99.9% O2. Interestingly, the sod2/sod2 mutant was rather more resistant to lithium and diamide than the wild‐type, whereas overexpression of SOD2 increased susceptibility of C. albicans to these compounds. The inverse effect of mitochondrial MnSOD on lithium toxicity was relieved when the sod2/sod2 and SOD2‐overexpressing cells were grown on the synthetic dextrose medium containing sulphur compounds such as methionine, cysteine, glutathione or sulphite, indicating that mitochondrial MnSOD may affect lithium toxicity through sulphur metabolism. Moreover, disruption or overexpression of SOD2 increased or decreased glutathione reductase activity and cyanide‐resistant respiration by alternative oxidase, respectively. Taken together, these findings suggest that mitochondrial MnSOD is important for stress responses, lithium toxicity and cyanide‐resistant respiration of C. albicans. Copyright © 2003 John Wiley & Sons, Ltd.
Saccharomyces cerevisiae QNS1 codes for NAD+ synthetase that is functionally conserved in mammals
Authors: Suda Yasuyuki , Tachikawa Hiroyuki , Yokota Ayako , Nakanishi Hideki , Yamashita Nobuhiko , Miura Yutaka , Takahashi Nobuhiro 
Published: July 2003

AbstractNAD+, an essential molecule involved in a variety of cellular processes, is synthesized through de novo and salvage pathways. NAD+ synthetase catalyses the final step in both pathways. Here we show that this enzyme is encoded by the QNS1 gene in Saccharomyces cerevisiae. Expression of Escherichia coli or Bacillus subtilis NAD+ synthetases was able to suppress the lethality of a qns1 deletion, while a B. subtilis NAD+ synthetase mutant with lowered catalytic activity was not. Overexpression of QNS1 tagged with HA led to elevated levels of NAD+ synthetase activity in yeast extracts, and this activity can be recovered by immunoprecipitation using anti‐HA antibody. An allele of QNS1 was constructed that carries a point mutation predicted to reduce the catalytic activity. Overexpression of this allele, qns1G521E, failed to elevate NAD+ synthetase levels and qns1G521E could not rescue the lethality caused by the depletion of Qns1p. These results demonstrate that NAD+ synthetase activity is essential for cell viability. A GFP‐tagged version of Qns1p displayed a diffuse localization in both the nucleus and the cytosol. Finally, the rat homologue of QNS1 was cloned and shown to functionally replace yeast QNS1, indicating that NAD+ synthetase is functionally conserved from bacteria to yeast and mammals. Copyright © 2003 John Wiley & Sons, Ltd.
Studies on the ATP3 gene of Saccharomyces cerevisiae: presence of two closely linked copies, ATP3a and ATP3b, on the right arm of chromosome II
Authors: Ohnishi Katsunori , Ishibashi Shinya , Kunihiro Masayuki , Satoh Takaaki , Matsubara Kiyo , Oku Soichiro , Ono Bun‐ichiro , Mabuchi Tadashi , Takeda Masaharu 
Published: July 2003

AbstractIn this paper, we present evidence that there are two closely linked copies of the ATP3 gene coding for the γ subunit of the F1F0‐ATPase complex (EC3.6.1.34) in four laboratory strains of Saccharomyces cerevisiae, even though the yeast genome project has reported that ATP3 is a single‐copy gene on chromosome II. We previously reported that the gene dosage (three copies) of ATP1 and ATP2 is coincident with the subunit number of F1‐α and F1‐β, but that the gene dosage of ATP3 was not consistent with the subunit stoichiometry of F1F0‐ATPase. By applying long PCR and gene walking analyses, we estimated that the two copies of ATP3 were approximately 20 kb apart, and we designated that which is proximal to the centromere ATP3a, while we named that which is distal ATP3b. The nucleotide sequences of the two copies of ATP3 were identical to the reported sequence in the W303‐1A, W303‐1B and LL20 strains, while only the DC5 strain had a single base substitution in its ATP3a. With the exception of this substitution, the other nucleotide sequences were identical to the upstream 860 bp and the downstream 150 bp. The differences between ATP3 with the single base substitution (Ser308 to Phe) and ATP3 without the substitution on the complementation of the ATP3 disruptant and on the maintenance of the mitochondrial DNA were observed, suggesting that Atp3ap and Atp3bp in the DC5 strain might have different functions. However, it should not always be necessary for yeast cells to carry different types of ATP3 because the other three strains carry the same type of ATP3. It was also demonstrated that the disruption of the ATP3 genes basically leads to a loss of wild‐type mtDNA, but the stability of the mtDNA is not dependent on the ATP3 alone. Copyright © 2003 John Wiley & Sons, Ltd.
NET1 and HFI1 genes of yeast mediate both chromosome maintenance and mitochondrial rho− mutagenesis
Authors: Koltovaya N. A. , Guerasimova A. S. , Tchekhouta I. A. , Devin A. B. 
Published: July 2003

AbstractAn increase in the mitochondrial rho− mutagenesis is a well‐known response of yeast cells to mutations in numerous nuclear genes as well as to various kinds of stress. Despite extensive studies for several decades, the biological significance of this response is still not fully understood. The genetic approach to solving this enigma includes a study of genes that are required for the high incidence of spontaneous rho− mutants. We have obtained mutations of a few nuclear genes of that sort and found that mutations in certain genes, including CDC28, the central cell‐cycle regulation gene, result in a decrease in spontaneous rho− mutability and simultaneously affect the maintenance of the yeast chromosomes and plasmids. Two more genes resembling CDC28 in this respect are identified in the present work as a result of the characterization of four new mutants. These two genes are NET1 and HFI1 which mediate important regulatory protein–protein interactions in the yeast cell. The effects of four mutations, including net1‐srm and hfi1‐srm, on the maintenance of the yeast mitochondrial genome, chromosomes and plasmids, as well as on the cell's sensitivity to ionizing radiation, are also described. The data presented suggest that the pleiotropic srm mutations determining coordinate changes in the fidelity of mitotic transmission of chromosomes, plasmids and mtDNA molecules identify genes that most probably operate high up in the hierarchy of the general genetic regulation of yeast. Copyright © 2003 John Wiley & Sons, Ltd.
Functional analysis of the cysteine residues and the repetitive sequence of Saccharomyces cerevisiae Pir4/Cis3: the repetitive sequence is needed for binding to the cell wall β‐1,3‐glucan
Authors: Castillo Luis , Martinez Ana I. , Garcerá Ana , Victoria Elorza M. , Valentín Eulogio , Sentandreu Rafael 
Published: July 2003

AbstractIdentification of PIR/CIS3 gene was carried out by amino‐terminal sequencing of a protein band released by β‐mercaptoethanol (β‐ME) from S. cerevisiae mnn9 cell walls. The protein was released also by digestion with β‐1,3‐glucanases (laminarinase or zymolyase) or by mild alkaline solutions. Deletion of the two carboxyterminal Cys residues (Cys214‐12aa‐Cys227‐COOH), reduced but did not eliminate incorporation of Pir4 (protein with internal repeats) by disulphide bridges. Similarly, site‐directed mutation of two other cysteine amino acids (Cys130Ser or Cys197Ser) failed to block incorporation of Pir4; the second mutation produced the appearance of Kex2‐unprocessed Pir4. Therefore, it seems that deletion or mutation of individual cysteine molecules does not seem enough to inhibit incorporation of Pir4 by disulphide bridges. In fks1Δ and gsc2/fks2Δ cells, defective in β‐1,3‐glucan synthesis, modification of the protein pattern found in the supernatant of the growth medium, as well as the material released by β‐ME or laminarinase, was evident. However, incorporation of Pir4 by both disulphide bridges and to the β‐1,3‐glucan of the cell wall continued. Deletion of the repetitive sequence (QIGDGQVQA) resulted in the secretion and incorporation by disulphide bridges of Pir4 in reduced amounts together with substantial quantities of the Kex2‐unprocessed Pir4 form. Pir4 failed to be incorporated in alkali‐sensitive linkages involving β‐1,3‐glucan when the first repetitive sequence was deleted. Therefore, this suggests that this sequence is needed in binding Pir4 to the β‐1,3‐glucan. Copyright © 2003 John Wiley & Sons, Ltd.
New ‘marker swap’ plasmids for converting selectable markers on budding yeast gene disruptions and plasmids
Authors: Voth Warren P. , Wei Jiang Yi , Stillman David J. 
Published: July 2003

AbstractMarker swap plasmids can be used to change markers for genes disrupted with nutritional markers in the yeast Saccharomyces cerevisiae. We describe 18 new marker swap plasmids, and we also review other plasmids available for marker conversions. All of these plasmids have long regions of flanking sequence identity, and thus the efficiency of homologous recombination mediated by marker conversion is very high. Marker swaps allow one to easily perform crosses to construct double mutant strains even if each of the disrupted strains contains the same marker, as is the case with the KanMX marker used in the yeast knockout collection. Marker swaps can also be used to change the selectable marker on plasmids, eliminating the need for subcloning. Copyright © 2003 John Wiley & Sons, Ltd.
The cell outgrowth secretory endosome (COSE): a specialized compartment involved in neuronal morphogenesis
Authors: Alberts Philipp , Galli Thierry 
Published: July 2003

AbstractThe role of intracellular membrane trafficking in cellular morphogenesis is still unclear. We propose here a prominent function of a recently identified compartment that we propose to call the cell outgrowth secretory endosome (COSE), the exocytosis of which is controlled by the v‐SNARE TIVAMP and by cell‐cell adhesion.
Induction of oxidative stress in rat brain by the metabolites accumulating in maple syrup urine disease
Authors: Bridi Raquel , Araldi Janaı́na , Sgarbi Miriam B. , Testa Carla G. , Durigon Karina , Wajner Moacir , Dutra‐Filho Carlos Severo 
Published: July 2003

AbstractMaple syrup urine disease (MSUD) is an inherited disorder caused by deficiency of branched‐chain l‐2‐keto acid dehydrogenase complex activity. Affected patients present severe brain dysfunction manifested as convulsions, coma, psychomotor delay and mental retardation. However, the underlying mechanisms of these neurological findings are virtually unknown. In this study, we tested the in vitro effect of l‐leucine, l‐isoleucine and l‐valine, the amino acids accumulating in MSUD, on the lipid peroxidation parameters chemiluminescence and thiobarbituric acid‐reactive substances (TBA‐RS), as well as on total radical‐trapping antioxidant potential (TRAP) and total antioxidant reactivity (TAR) in cerebral cortex from 30‐day‐old rats. l‐Leucine significantly increased chemiluminescence and TBA‐RS measurements and markedly decreased TRAP and TAR values. l‐Isoleucine increased chemiluminescence and decreased TRAP measurements, but TAR and TBA‐RS levels were not altered by the amino acid. Finally, TRAP measurement was diminished by l‐valine. The results indicate a stimulation of lipid peroxidation and a reduction of brain capacity to efficiently modulate the damage associated with an increased production of free radicals by the branched‐chain amino acids (BCAAs) accumulated in MSUD. It is therefore tempting to speculate that oxidative stress may be implicated in the brain damage found in MSUD patients.
An attempt at estimating the effective fishing height of the bottom trawl using acoustic survey recordings
Authors: Hjellvik Vidar , Michalsen Kathrine , Aglen Asgeir , Nakken Odd 
Published: July 2003

Abstract
For species like cod and haddock, commonly distributed from bottom to far above bottom, swept area (bottom trawl) indices and acoustic indices of abundance cover different fractions of the stock. It has been argued that a combination of the two density estimates, into one estimate of absolute abundance, will improve the reliability of the survey results. The effective fishing height of the trawl may not be equal to the headline height of the trawl. In response to vessel noise, fish in the pelagic zone may swim towards the bottom. The bottom trawl will thus catch fish higher in the water column than the height of the trawl opening. Vertical herding is highly dependent on the size of the fish and their vertical distribution pattern. In this paper, bottom-trawl-catches and acoustic recordings of northeast Arctic cod, from annual surveys conducted in the Barents Sea seasonally over the past few years, have been compared. Differences in the relationship between the two methods are discussed regarding fish length, time of day, season, year, vertical distribution, and depth. Only “clean” stations, with regard to species and length distribution, were used in the analysis. In order to combine the swept area and acoustic estimates the effective catch height of the bottom trawl must be known. Therefore, the catchability of the trawl as a function of height above bottom has been estimated for three different length groups by fitting a logistic model to the data and by examining patterns in the correlation between trawl catches and acoustic densities. The results were equivocal.