bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sensitivities of benzodiazepine receptor binding and muscarinic acetylcholine receptor binding for the detection of neural cell death caused by sodium nitroprusside microinjection in rat brain
Authors: Inoue Osamu , Yanamoto Kazuhiko , Fujiwara Yoshiko , Hosoi Rie , Kobayashi Kaoru , Tsukada Hideo 
Published: May 2003

AbstractSodium nitroprusside (SNP) was microinjected into rat cerebral cortex and changes in muscarinic acetylcholine receptor (mAChR) binding and benzodiazepine receptor (BZR) binding were followed for 24 h after the infusion using [3H]‐N‐methyl‐4‐piperidyl benzilate ([3H]‐NMPB) and [3H]‐flumazenil, respectively, as a radioligand. The microinjection of SNP dose‐dependently caused significant neural cell death 3 h after infusion, with the area of cell death becoming extensive 24 h after infusion. Neither SIN‐1 nor NOC‐18, other types of NO donors, caused neural cell death. Together with the result that deferoxamine, an iron‐chelating agent, protected SNP‐induced brain injury indicated important roles of iron‐related radicals in SNP cytotoxicity in rat brain. In vitro [3H]‐NMPB binding was significantly reduced in parallel with the time course of neural cell death detected by TTC staining and Nissl staining. In contrast, [3H]‐flumazenil binding was essentially unaltered during the 24‐h period after the SNP infusion. Similar results were observed in in vivo binding experiments. In vivo [3H]‐NMPB binding was found to be much more sensitive at detecting cell death caused by SNP. On the other hand, [3H]‐flumazenil binding in vivo was relatively insensitive to SNP‐induced cell death. These results indicate that mAChR binding may be superior to BZR binding for detecting cell death in brain tissue, in contrast to what was previously thought. Synapse 49:134–141, 2003. © 2003 Wiley‐Liss, Inc.
Role for calbindin‐D28K in in vitro classical conditioning of abducens nerve responses in turtles
Authors: Keifer Joyce , Brewer Boone T. , Meehan Phillip E. , Brue Richard J. , Clark Timothy G. 
Published: May 2003

AbstractIntracellular calcium has a pivotal role in synaptic modifications that may underlie learning and memory. The present study examined whether there were changes in immunoreactivity levels of the AMPA receptor subunits GluR2/3 and calcium binding proteins during classical conditioning recorded in the abducens nerve of in vitro brain stem preparations from turtles. The results showed that abducens motor neurons in unconditioned turtle brain stems were immunopositive for GluR2/3, calbindin‐D28K, and calmodulin, but were immunonegative for parvalbumin. After classical conditioning, immunoreactivity for calbindin‐D28K in the abducens motor nuclei was significantly reduced, whereas there were no significant changes in GluR2/3, calmodulin, or parvalbumin. This reduction in calbindin‐D28K immunoreactivity was not observed following conditioning in the NMDA receptor antagonist AP‐5, which blocked conditioned responses, suggesting that these changes are NMDA receptor‐dependent. Moreover, the degree of the decrease in calbindin‐D28K immunoreactivity was negatively correlated with the level of conditioning. Consistent with the immunocytochemical findings, Western blot analysis showed that calbindin‐D28K protein levels were reduced after classical conditioning. The results support the hypothesis that in vitro classical conditioning of abducens nerve responses utilizes intracellular calcium‐dependent signaling pathways that require NMDA receptor function and suggest a specific role for the calcium binding protein calbindin‐D28K. Synapse 49:106–115, 2003. © 2003 Wiley‐Liss, Inc.
Differential effects of amphetamine transport vs. dopamine reverse transport on particulate PKC activity in striatal synaptoneurosomes
Authors: Giambalvo Cecilia T. 
Published: May 2003

AbstractAmphetamine has been shown to increase striatal particulate protein kinase C (PKC) activity [Giambalvo (1992b) Neuropharmacology 31:1211–1222]. The present study examined possible mechanisms involved. Specifically, the effects of calcium, endogenous DA, and DA receptors on the amphetamine‐induced increase in PKC activity in striatal synaptoneurosomes were examined. Naïve rats and rats pretreated with N‐ethoxy‐carbonyl‐2‐ethoxy‐1,2‐dihydroquinolone (EEDQ, i.p.), a nonselective irreversible receptor antagonist, or with α‐methyl‐p‐tyrosine (AMPT, i.p.), a DA synthesis inhibitor, were sacrificed and striatal synaptoneurosomes were prepared. The tissue was incubated with amphetamine, with and without calcium, and PKC activity was then determined by the endogenous phosphorylation of endogenous substrate proteins, as described previously [Giambalvo (1988a) Biochem Pharmacol 37:4001–4007]. It was found that calcium enhanced the effect of amphetamine on PKC activity, even in rats pretreated with EEDQ. Intracellular calcium was required since pretreatment with 1,2‐bis (2‐aminophenoxy) ethane‐N, N, N, N‐tetracetic acid acetoxymethyl ester (BAPTA‐AM) in vitro attenuated the amphetamine‐induced increase in PKC activity, resulting in an inhibition of PKC activity instead. Likewise, endogenous DA was essential since pretreatment with AMPT resulted in a similar amphetamine‐induced inhibition of PKC activity. Pretreatment with AMPT did not alter the inhibitory effect of the D2 DA agonist, LY 171555, on PKC activity. It did, however, abolish the calcium‐dependent stimulatory effect of the D1 agonist SKF 38393 on PKC activity, rendering it inhibitory regardless of calcium. Considering that both BAPTA‐AM and AMPT pretreatments, which diminished DA release without affecting uptake via different mechanisms, produced similar inhibitory effects on PKC activity by amphetamine, these results suggest that the inward transport of amphetamine had an inhibitory effect on PKC activity. In contrast, the outward transport of DA seemed to have a stimulatory effect on PKC activity since incubation with low sodium or with ouabain, conditions that promote DA reverse‐transport, increased PKC activity. These results showed that PKC activity was altered differently during inward vs. outward transport. The amphetamine‐induced increase in PKC activity was attenuated by pretreatment with DA uptake blockers (nomifensine, GBR 12935, and bupropion), even though these drugs by themselves also increased PKC activity. This effect was diminished by calcium and persisted in rats pretreated with EEDQ. Thus, calcium had a differential effect on the PKC activity induced by a transported substrate (amphetamine) vs. nontransported inhibitors (DA uptake blockers). Synapse 49:125–133, 2003. © 2003 Wiley‐Liss, Inc.
Microbiological evaluation of toxicity of three polycyclic aromatic hydrocarbons and their decomposition products formed by advanced oxidation processes
Authors: Jamroz Teresa , Ledakowicz Stanisław , Miller Jacek S. , Sencio Barbara 
Published: May 2003

AbstractThe toxicity of benzo[a]pyrene, chrysene, and fluorene and their decomposition products formed by advanced oxidation processes (AOPs) was investigated using biotests with Escherichia coli and Vibrio fischeri. The polycyclic aromatic hydrocarbons (PAHs) were not highly toxic to either bacterial strain; the toxicity of their degradation products depended on the method of chemical processing. Inhibition of more than 27% was observed with products formed by oxidation of the PAHs, by AOP methods without hydrogen peroxide. Toxicity as high as 100% was observed after the combined action of hydrogen peroxide and other oxidizing agents. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 187–191, 2003
Review: Environmental exposure to mercury and its toxicopathologic implications for public health
Authors: Tchounwou Paul B. , Ayensu Wellington K. , Ninashvili Nanuli , Sutton Dwayne 
Published: May 2003

AbstractMercury is a toxic and hazardous metal that occurs naturally in the earth's crust. Natural phenomena such as erosion and volcanic eruptions, and anthropogenic activities like metal smelting and industrial production and use may lead to substantial contamination of the environment with mercury. Through consumption of mercury in food, the populations of many areas, particularly in the developing world, have been confronted with catastrophic outbreaks of mercury‐induced diseases and mortality. Countries such as Japan, Iraq, Ghana, the Seychelles, and the Faroe Islands have faced such epidemics, which have unraveled the insidious and debilitating nature of mercury poisoning. Its creeping neurotoxicity is highly devastating, particularly in the central and peripheral nervous systems of children. Central nervous system defects and erethism as well as arrythmias, cardiomyopathies, and kidney damage have been associated with mercury exposure. Necrotizing bronchitis and pneumonitis arising from inhalation of mercury vapor can result in respiratory failure. Mercury is also considered a potent immunostimulant and ‐suppressant, depending on exposure dose and individual susceptibility, producing a number of pathologic sequelae including lymphoproliferation, hypergammaglobulinemia, and total systemic hyper‐ and hyporeactivities. In this review we discuss the sources of mercury and the potential for human exposure; its biogeochemical cycling in the environment; its systemic, immunotoxic, genotoxic/carcinogenic, and teratogenic health effects; and the dietary influences on its toxicity; as well as the important considerations in risk assessment and management of mercury poisoning. © 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 149–175, 2003.
Gene regulation in response to protein disulphide isomerase deficiency
Authors: Nørgaard Per , Tachibana Christine , Bruun Anette W. , Winther Jakob R. 
Published: May 2003

AbstractWe have examined the activities of promoters of a number of yeast genes encoding resident endoplasmic reticulum proteins, and found increased expression in a strain with severe protein disulphide isomerase deficiency. Serial deletion in the promoter of the MPD1 gene, which encodes a PDI1‐homologue, revealed a cis‐acting element responding to deficiency of protein disulphide isomerase activity (designated CERP). The presence of the sequence element is necessary and sufficient for the upregulation in response to disulphide isomerase deficiency, as measured by a minimal promoter containing the CERP element. The sequence (GACACG) does not resemble the unfolded protein response element. It is present in the upstream regions of the MPD1, MPD2, KAR2, PDI1 and ERO1 genes. Copyright © 2003 John Wiley & Sons, Ltd.
Moderately lipophilic carboxylate compounds are the selective inducers of the Saccharomyces cerevisiae Pdr12p ATP‐binding cassette transporter
Authors: Hatzixanthis Kostas , Mollapour Mehdi , Seymour Ian , Bauer Bettina E. , Krapf Gerd , Schüller Christoph , Kuchler Karl , Piper Peter W. 
Published: May 2003

AbstractSaccharomyces cerevisiae displays very strong induction of a single ATP‐binding cassette (ABC) transporter, Pdr12p, when stressed with certain weak organic acids. This is a plasma membrane pump catalysing active efflux of the organic acid anion from the cell. Pdr12p action probably allows S. cerevisiae to maintain lower intracellular levels of several weak organic acid preservatives than would be expected on the basis of the free equilibration of the acid across the cell membrane. This in turn facilitates growth in the presence of these preservatives and therefore yeast spoilage of food materials. Pdr12p appears to confer resistance to those carboxylic acids that, to a reasonable degree, partition into both the lipid bilayer and aqueous phases. Its gene (PDR12) is strongly induced by sorbate, benzoate and certain other moderately lipophilic carboxylate compounds, but not by organic alcohols or high levels of acetate. PDR12 induction reflects the operation of a previously uncharacterized S. cerevisiae stress response, for which the induction signal is probably a high intracellular pool of the organic acid anion. Copyright © 2003 John Wiley & Sons, Ltd.
A ‘marker switch’ approach for targeted mutagenesis of genes in Schizosaccharomyces pombe
Authors: MacIver Fiona H. , Glover David. M. , Hagan Iain M. 
Published: May 2003

AbstractThe completion of the Schizosaccharomyces pombe genome sequencing project has led to a dramatic acceleration of gene characterization in this system. Once a gene has been identified, the challenge then comes in using reverse genetics to generate a range of mutants in this gene of interest so that the powerful genetics and wealth of genetic backgrounds available in Sz. pombe can be exploited to study the function of the newly identified molecule. Beyond simple PCR‐tagging approaches, the high frequency with which illegitimate recombination occurs in Sz. pombe has made the manipulation of some loci complex, time consuming and a process of trial and error. Here we describe a simple ‘marker switch’ approach that enables the rapid selection of integration events at the locus of interest from an excessive background of integration at heterologous sites. We use the generation of temperature‐sensitive mutations in the plo1+ gene to validate this approach. Copyright © 2003 John Wiley & Sons, Ltd.
An analysis of the Candida albicans genome database for soluble secreted proteins using computer‐based prediction algorithms
Authors: Lee Samuel A. , Wormsley Steven , Kamoun Sophien , Lee Austin F. S. , Joiner Keith , Wong Brian 
Published: May 2003

AbstractWe sought to identify all genes in the Candida albicans genome database whose deduced proteins would likely be soluble secreted proteins (the secretome). While certain C. albicans secretory proteins have been studied in detail, more data on the entire secretome is needed. One approach to rapidly predict the functions of an entire proteome is to utilize genomic database information and prediction algorithms. Thus, we used a set of prediction algorithms to computationally define a potential C. albicans secretome. We first assembled a validation set of 47 C. albicans proteins that are known to be secreted and 47 that are known not to be secreted. The presence or absence of an N‐terminal signal peptide was correctly predicted by SignalP version 2.0 in 47 of 47 known secreted proteins and in 47 of 47 known non‐secreted proteins. When all 6165 C. albicans ORFs from CandidaDB were analysed with SignalP, 495 ORFs were predicted to encode proteins with N‐terminal signal peptides. In the set of 495 deduced proteins with N‐terminal signal peptides, 350 were predicted to have no transmembrane domains (or a single transmembrane domain at the extreme N‐terminus) and 300 of these were predicted not to be GPI‐anchored. TargetP was used to eliminate proteins with mitochondrial targeting signals, and the final computationally‐predicted C. albicans secretome was estimated to consist of up to 283 ORFs. The C. albicans secretome database is available at http://info.med.yale.edu/intmed/infdis/candida/ Copyright © 2003 John Wiley & Sons, Ltd.
KlROM2 encodes an essential GEF homologuein Kluyveromyces lactis
Authors: Lorberg Anja , Schmitz Hans‐Peter , Gengenbacher Ute , Heinisch Jürgen J. 
Published: May 2003

AbstractCellular integrity in yeasts is ensured by a rigid cell wall whose synthesis is controlled by a MAP kinase signal transduction cascade. In Saccharomyces cerevisiae upstream regulatory components of this MAP kinase pathway involve a single protein kinase C, which is regulated in part by interaction with the small GTPase Rho1p. This small G protein is in turn rendered inactive (GDP‐bound) or is activated (GTP‐bound) by the influence of GTPase activating proteins (GAPs) and the GDP/GTP exchange factors (GEFs), respectively. We report here on the isolation of a gene from Kluyveromyces lactis, KlROM2, which encodes a member of the latter protein family. The nucleotide sequence contains an open reading frame of 1227 amino acids, with an overall identity of 57% to the Rom2 protein of S. cerevisiae. Four conserved sequence motifs could be identified: a RhoGEF domain, a DEP sequence, a CNH domain and a less conserved pleckstrin homology (PH) sequence. Klrom2 null mutants show a lethal phenotype, which indicates that the gene may encode the only functional GEF regulating the cellular integrity pathway in K. lactis. Conditional genomic expression of KlROM2 resulted in sensitivity towards caffeine and Calcofluor white as typical phenotypes of mutants defective in this pathway. Overexpression of KlROM2 from multicopy plasmids under the control of the ScGAL1 promoter severely impaired growth in both S. cerevisiae and in K. lactis. The fact that the lethal phenotype was not prevented in mpk1 deletion mutants indicates that growth inhibition is not simply caused by hyperactivation of the Pkc1p signal transduction pathway. The GeneBank Accession No. for KlROM2 is AF421953. Copyright © 2003 John Wiley & Sons, Ltd.
Isolation of the MNN9 gene of Yarrowia lipolytica (YlMNN9) and phenotype analysis of a mutant ylmnn9Δ strain
Authors: Jaafar Lahcen , León Maela , Zueco Jesús 
Published: May 2003

AbstractIn this work we describe the isolation of the Yarrowia lipolytica homologue of Saccharomyces cerevisiae MNN9 gene, which we have named YlMNN9, and the phenotype analysis of a Y. lipolytica strain containing the disrupted YlMNN9 allele. YlMNN9 was cloned using degenerate consensus oligonucleotides to generate specific probes that were in turn used to screen mini‐gene libraries. The gene is defined by a 1014 bp ORF predicted to encode a protein 337 amino acids long that shares significant homology with the Mnn9ps of S. cerevisiae, Candida albicans and Hansenula polymorpha, including a putative N‐terminal transmembrane domain. Disruption of YlMNN9 leads to phenotypes such as resistance to sodium orthovanadate and sensitivity to hygromycin B, compatible with a glycosylation defect, and hypersensitivity to Calcofluor white, Congo red or zymolyase, characteristic of cell wall defects. Analysis of cell wall proteins present in β‐mercaptoethanol and zymolyase extracts showed significant differences between the parental and the ylmnn9Δ strain. These results suggest that, as has been the case with the mnn9 strain of S. cerevisiae, the ylmnn9Δ strain we present in this work, could be used to study the cell wall proteins of Y. lipolytica and how they are organized into the cell wall. The complete YlMNN9 sequence is available from GenBank under Accession No. AF441127. Copyright © 2003 John Wiley & Sons, Ltd.
A novel d‐leucine‐containing Conus peptide: diverse conformational dynamics in the contryphan family
Authors: Jacobsen R.B. , Jimenez E.C. , De la Cruz R.G.C. , Gray W.R. , Cruz L.J. , Olivera B.M. 
Published: May 2003

Abstract: A Conus peptide family (the contryphans) is noteworthy because of the presence of a post‐translationally modified d‐amino acid in all members of the family. A new contryphan peptide, Leu‐contryphan‐P, was isolated from the venom of Conus purpurascens; the sequence of this peptide is:Gly‐Cys‐Val‐D‐Leu‐Leu‐Pro‐Trp‐Cys‐OHThis is the first known occurrence of d‐leucine in a Conus peptide. The discovery of Leu‐contryphan‐P suggests that there may be branches of the contryphan peptide family that diverge much more in sequence than previously anticipated. Several natural contryphans provide dramatic examples of inter‐conversion between multiple conformational states in small constrained peptides. The contryphans that have 4‐trans‐hydroxyproline and d‐tryptophan in positions 3 and 4, respectively, exhibit two peaks under reverse‐phase HPLC conditions, indicating interconversion between two discrete conformations. However, [l‐Trp4]contryphan‐Sm (with l‐Trp substituted for d‐Trp) exhibits a single, broad peak that elutes later than the natural peptide, suggesting that d‐Trp stabilizes a conformation in which hydrophobic residues are buried. Leu‐contryphan‐P which has valine and d‐leucine instead of 4‐trans‐hydroxyproline and d‐tryptophan shows only a single peak that elutes much later than the other contryphans.
Assessment of HER‐2/neu overexpression and/or gene amplification in breast carcinomas: should in situ hybridization be the method of choice?
Authors: SAUER TORILL , WIEDSWANG GRO , BOUDJEMA GHANIA , CHRISTENSEN HANNE , KÅRESEN ROLF 
Published: May 2003

Aims: Since the release of Herceptin®, pathology laboratories have been requested to test breast carcinomas for HER‐2/neu overexpression and/or gene amplification. Standardized IHC and FISH are mandatory in order to get reliable results, but there are problems even with standardized procedures. We decided to evaluate the two methods to determine which, or possibly if both, should be the primary investigation method(s).Methods and Results: The material consisted of 215 primary invasive breast carcinomas with complete clinical follow‐up of 15 years. HER‐2/neu protein expression was determined for all specimens, whereas FISH for assessing HER‐2/neu gene signal number was done in 165 cases. IHC was double‐checked with two or three different antibodies in 35 tumours, including all cases with discrepancies between IHC and FISH. Among these, there were discrepancies in a third. IHC overexpression of HER‐2/neu was found in 13% and gene amplification in 18%. Discordance between IHC and FISH was found in 11 cases (8%). Five tumours were IHC+/FISH− and six were IHC−/FISH+. IHC and FISH positive cases as well as FISH only positive tumours had the same prognosis respecting survival. Tumours with >2 but ≤4 HER‐2 gene signals per nucleus had the same survival as cases with >4 gene signals per nucleus. In contrast, cases with IHC overexpression without gene amplification had a prognosis similar to that of IHC−/FISH− tumours.Conclusions: From our data, it seems to be more important to assess HER‐2/neu gene amplification than IHC overexpression. Failure to detect FISH‐amplified (IHC‐negative) cases would have an adverse effect on the survival of these patients. On the other hand, IHC overexpression tumours without gene amplification appear to belong to a better prognostic group, and failure to detect them would probably not have a negative effect on the survival of these women. Even though FISH is a more complex and expensive procedure, it should be considered the method of choice for primary assessment of HER‐2/neu status in breast cancer patients.
Oral and general health‐related quality of life with conventional and implant dentures
Authors: Heydecke Guido , Locker David , Awad Manal A. , Lund James P. , Feine Jocelyne S. 
Published: May 2003

Abstract – Implant overdentures and conventional prostheses have been compared in several trials using a variety of functional and oral health‐related quality of life (OHQOL) outcomes. In this paper, we describe the impact of implant overdentures on general and OHQOL in seniors.Objectives: To compare the oral health‐related and general quality of life of seniors (aged 65–75 years) who received either mandibular implant overdentures or conventional dentures.Methods: Sixty edentulous patients were recruited. Thirty received mandibular overdentures retained by two implants (IOD) and a conventional maxillary denture, the other 30 subjects received new maxillary and mandibular conventional complete dentures (CD). All completed the 20‐item version of the Oral Health Impact Profile (OHIP‐20) before treatment, then at two and 6 months after delivery of the dentures. The SF‐36 general health questionnaire was completed at baseline and 6 months only.Results: Pretreatment and 6‐month data from 55 subjects were analyzed. Those who received the IODs had significantly better OHIP‐20 total scores at 6 months. Results for IOD subjects were also superior in the functional limitation, physical pain, physical disability and psychological disability subscales. While no significant between group difference was found on the SF‐36 health survey, significant pre–post‐treatment differences within the IOD group were detected for the role emotional, vitality and the social function scales.Conclusions: Mandibular overdentures retained by two implants provide elderly patients with better OHQOL. General health‐related quality of life improved in the implant group.