bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence that oxidative stress is involved in the inhibitory effect of proline on Na+,K+‐ATPase activity in synaptic plasma membrane of rat hippocampus
Authors: Franzon Renata , Lamers Marcelo L. , Stefanello Francieli M. , Wannmacher Clóvis M.D. , Wajner Moacir , Wyse Angela T.S. 
Published: July 2003

AbstractIn the present study, we investigated the effect of Vitamins E and C on the inhibition of Na+,K+‐ATPase activity provoked by proline (Pro) administration in rat hippocampus. Five‐day‐old rats were pretreated for 1 week with daily i.p. administration of saline (control) or Vitamin E (40 mg/kg) and Vitamin C (100 mg/kg). Twelve hours after the last injection, animals received one single injection of Pro (12.8 μmol/g of body weight) or saline and were killed 1 h later. Results showed that Na+,K+‐ATPase activity was decreased in the Pro‐treated rats and that the pretreatment with Vitamins E and C prevented this effect. In another set of experiments, we investigated the in vitro effect of 1.0 mM Pro on Na+,K+‐ATPase activity from synaptic membranes of hippocampus of rats. Pro significantly inhibited (30%) Na+,K+‐ATPase activity. We also evaluated the effect of preincubating glutathione, trolox and Nϖ‐nitro‐l‐arginine methyl ester (l‐NAME) alone or combined with Pro on Na+,K+‐ATPase activity. Tested drugs did not alter Na+,K+‐ATPase activity, but glutathione prevented the inhibitory effect of Pro on this enzyme activity. These results suggest that the in vivo and in vitro inhibitory effect of Pro on Na+,K+‐ATPase activity is probably mediated by free radicals that may be involved in the neurological dysfunction found in hyperprolinemic patients.
Increment at molt for the Norway lobster (Nephrops norvegicus) from the south coast of Portugal
Authors: Castro M , Encarnação P , Henriques P 
Published: July 2003

Abstract
The increment at molt for Nephrops norvegicus was studied with the objective of obtaining a model for prediction of post-molt size based on pre-molt size for the population from the south coast of Portugal. Wild animals were maintained in a specially prepared laboratory facility until they molted. Individual values of increment at molt were obtained and used to evaluate alternative models and estimate their parameters. Six alternative models, used previously by several authors to relate pre- and post-molt size, were modified so that increment at molt was the dependent variable and pre-molt size the independent variable. These included the linear relationship of the growth factor (GF) on pre-molt size, the Hiatt equation, post-molt size a power function of pre-molt size, the hyperbolic function, GF exponential function of pre-molt size and the Misra equation.
The analysis of the data showed that none of the models could be used to predict increment at molt for either sex. The distribution of the increment at molt was a random normal variable, with mean values not significantly different between sexes, 2.78 mm for males and 2.26 mm for females, variances 0.47 and 0.59, respectively.
An analysis of the models suggests that using post-molt size or the GF as dependent variables may lead to a misinterpretation of the dependency of these variables on pre-molt size. It is suggested that the increment at molt should be the variable of interest for predicting post-molt size. The choice of a mathematical formulation should, besides having biological meaning, have the capacity of expressing a true relationship between increment at molt and pre-molt carapace length, namely, be able to model several options for the increment at molt after maturity, including a steady increase of the increment through life, the stabilization of the increment after maturity or the decrease of the increment for larger sizes.
Accounting for length- and depth-dependent diel variation in catchability of fish and invertebrates in an annual bottom-trawl survey
Authors: Benoít Hugues P , Swain Douglas P 
Published: July 2003

Abstract
Diel variation in the catchability of 51 species of fish and 13 invertebrate taxa from an annual bottom-trawl survey of the southern Gulf of St. Lawrence was examined using generalized linear (Poisson) models. Two approaches were used: comparative fishing based on spatially paired day and night tows, and statistical control of spatio-temporal effects in regular survey data. The two approaches provided remarkably similar results. Furthermore, species-specific results were consistent between survey time periods where different vessels were used, and were quite comparable to results from other studies conducted in separate geographic areas. Where sufficient data existed, we considered both length and depth dependencies in diel variation in catchability. We commonly found significant length dependency for groundfish species and the pervasive pattern was for higher nighttime catches of small fish, the magnitude of the effect generally decreasing with increasing length. In contrast, water depth had a much less important impact, except for a few species. When considered jointly, however, patterns in length/depth dependency were not always clear. Given length-dependent geographic and bathymetric patterns in species distribution, the potential for confounding length and depth dependencies exists and correction factors for diel variation in catchability need to be applied cautiously.
Age determination, validation and growth of Grand Bank yellowtail flounder (Limanda ferruginea)
Authors: Dwyer Karen S , Walsh Stephen J , Campana Steven E 
Published: July 2003

AbstractYellowtail flounder (Limanda ferruginea) (Storer, 1839) on the Grand Bank off Newfoundland were traditionally aged using surface-read whole otoliths. Age determination of otoliths from recaptures of fish tagged in the early 1990s indicated that the traditional ageing technique was underestimating the ages of yellowtail flounder when compared with the time at liberty. Age comparisons between whole and thin-sectioned otoliths showed agreement in age readings up to 7 years; thereafter whole otoliths tended to give much lower ages than those estimated by thin sections. Length–frequency analysis of pelagic and demersal juveniles, captive rearing of juveniles and marginal increment analysis all corroborated age determination based on thin sections. Tag-recaptures and bomb radiocarbon assays validated age interpretations based on thin sections in young and old yellowtail flounder, respectively. Ages were validated up to 25 years for females and 21 years for males. However, because of increased narrowing of annuli in thin-sectioned otoliths from old fish, even thin sections may underestimate the true age of the fish. von Bertalanffy growth curve parameters (combined sexes) were L∞ = 55.6 cm total length, K=0.16 and t0=−0.003. These results challenge the conventional view that yellowtail flounder on the Grand Banks are a relatively fast growing, short-lived species.
Decreased hippocampal NMDA, but not kainate or AMPA receptors in bipolar disorder
Authors: Scarr E , Pavey G , Sundram S , MacKinnon A , Dean B 
Published: July 2003

Objectives:  The purpose of this study was to determine whether there are changes in the density of ionotropic glutamate receptors in the hippocampus of subjects with bipolar disorder.Methods:  Using in situ radioligand binding with semiquantitative autoradiography, we measured the density of [3H]MK‐801, [3H]CGP39653, [3H]AMPA and [3H]kainate binding in hippocampi, obtained postmortem, from eight subjects with type 1 bipolar disorder and 8 age‐ and sex‐matched controls.Results:  In subjects with bipolar disorder there were significant decreases in the density of [3H]MK‐801 binding in the Cornu Ammonis (CA) 3 (mean ± SEM; 108.8 ± 12.2 versus 166.2 ± 18.0 fmol/mg ETE, p < 0.005) as well as the pyramidal (102.8 ± 9.2 versus 136.6 ± 11.2 fmol/mg ETE, p < 0.05) and polymorphic (21.73 ± 6.5 versus 53.26 ± 11.6 fmol/mg ETE, p < 0.05) layers of the subiculum. In addition, two‐way analysis of variance (ANOVA) revealed a decrease in the density of [3H]CGP39653 binding across the hippocampal formation in bipolar subjects, which did not reach significance in any subregion. There were no changes in the densities of [3H]AMPA or [3H]kainate binding in these subjects.Conclusions:  [3H]CGP39653 and [3H]MK‐801 bind to the glutamate binding site and open ion channel of the n‐methyl‐d‐aspartate (NMDA) receptor, respectively. Therefore, these data suggest that there is a decrease in the number of open ion channels associated with no significant change in the apparent density of NMDA receptors in regions of the hippocampus from subjects with bipolar disorder.
Diagnostic classification of organic psychiatric disorders after aneurysmal subarachnoid hemorrhage: a comparison between ICD‐10, DSM‐IV and the Lindqvist & Malmgren classification system
Authors: Rödholm M. , Hellström P. , Bilting M. , Starmark J.‐E. 
Published: July 2003

Objective: There is no universally accepted consensus for organic psychiatric disorders (OPDs) between the two major classifications, ICD‐10 and DSM‐IV. The aim was to compare the coverage of these systems with the Lindqvist & Malmgren (LM) classification system for organic psychiatry.Method: Organic psychiatric disorders were diagnosed according to ICD‐10, DSM‐IV, and the LM system in 119 patients 12 months after surgery as a result of aneurysmal subarachnoid hemorrhage.Results: Among 35 patients with astheno‐emotional (AE) disorder (LM system), 83% (95% CI: 67–92%) had mild cognitive disorder (MCD) according to ICD‐10 clinical descriptions and diagnostic guidelines (CDDG), 49% (95% CI: 33‐64%) had MCD according to ICD‐10 diagnostic criteria for research (DCR), and 34% (95% CI: 21–51%) had mild neurocognitive disorder according to DSM‐IV. The coverage for other OPDs did not differ between the systems.Conclusion: The coverage for AE disorder (LM system) was significantly higher than the corresponding diagnoses of the ICD‐10 and DSM‐IV systems. Modifications of the latter systems are suggested.
Serum lipid levels and suicide attempts
Authors: Lee Heon‐Jeong , Kim Yong‐Ku 
Published: July 2003

Objective: To determine whether a correlation exists between lower serum lipid concentrations and increased suicide risk.Method: Serum lipid profiles were pair‐matched for 60 patients who had recently experienced failed attempts at suicide and equal numbers of non‐suicidal psychiatric patients, and normal controls. Suicide attempt severity was scored using Weisman and Worden's risk‐rescue rating scale.Results: (a) Total serum cholesterol and low density lipoprotein levels were found to be lower in the parasuicidal population at statistically significant levels (P < 0.01 and <0.05, respectively); (b) triglyceride concentrations were lower in suicide attempters with major depression compared with non‐suicidal depressed patients; and (c) risk‐rescue rating scores were negatively correlated with total serum cholesterol levels (r = −0.347, P = 0.007).Conclusion: Low lipid metabolism may be a potential biological marker in the assessment of suicide risk. Further investigations are necessary to elucidate the biological mechanisms of these findings.
The interaction between salinity and boron toxicity affects the subcellular distribution of ions and proteins in wheat leaves
Authors: WIMMER M. A. , MÜHLING K. H. , LÄUCHLI A. , BROWN P. H. , GOLDBACH H. E. 
Published: July 2003

ABSTRACTSalinity aggravates B toxicity symptoms in several plant species. In the present study the interactive effects of B toxicity and salinity stresses on the subcellular distribution of boron, cations and proteins in basal and apical leaf sections of wheat were investigated. High B supply increased total B concentrations in all leaf parts, but values remained below 25 mg B kg−1 dry weight (DW) in basal sections, whereas they reached more than 600 mg B kg−1 DW in leaf tips. In basal leaf sections intercellular soluble B concentrations closely reflected the external supply, whereas intracellular soluble B concentrations remained lower by a factor of two, indicating some retention of excess B in the apoplast. Combined salinity and B toxicity stresses significantly increased soluble B concentrations in inter‐ and intracellular compartments of basal leaf sections in comparison with either stress alone, probably related to salinity‐induced changes in water status. The combined stresses also induced quantitative and qualitative changes in inter‐, but not intracellular protein composition. Most obvious was the induction of a 25 kDa protein and an increase in amount of a 33 kDa protein. It is suggested that these changes might be due to structural modifications of the cell wall. The concentration of soluble boron in cells is proposed to be an indicator of boron toxicity.
Dissecting the response to dehydration and salt (NaCl) in the resurrection plant Craterostigma plantagineum
Authors: SMITH‐ESPINOZA C. J. , RICHTER A. , SALAMINI F. , BARTELS D. 
Published: July 2003

ABSTRACTAlthough desiccation tolerant, the resurrection plant Craterostigma plantagineum is sensitive to relatively low levels of sodium chloride. Exposure to sodium chloride, but not dehydration, led to accumulation of sodium ions in leaves and roots and caused irreversible wilting. The effects of salt and dehydration on transcript accumulation patterns were studied by using selected cDNA clones that were related to water stress. Most of the clones represented genes that were up‐regulated in response to both treatments. Among the transcripts specifically up‐regulated by dehydration were RNAs encoding transcripts with homology to aquaporins. Expression analysis revealed dehydration‐specific profiles of late embryogenesis abundant (LEA) genes, which differed from the patterns observed for the same genes under sodium chloride stress. The interconversion of octulose and sucrose, which is characteristic for the desiccation/rehydration cycle in C. plantagineum leaves, was not activated by sodium chloride. The present results suggest that dehydration‐specific responses involve the synchronized expression of specific genes and the presence of a determined concentration of sucrose. These dehydration responses were not detected in response to sodium chloride treatment.
The ‘hydrology’ of leaves: co‐ordination of structure and function in temperate woody species
Authors: SACK L. , COWAN P. D. , JAIKUMAR N. , HOLBROOK N. M. 
Published: July 2003

ABSTRACTThe hydraulic conductance of the leaf lamina (Klamina) substantially constrains whole‐plant water transport, but little is known of its association with leaf structure and function.Klaminawas measured for sun and shade leaves of six woody temperate species growing in moist soil, and tested for correlation with the prevailing leaf irradiance, and with 22 other leaf traits.Klaminavaried from 7.40 × 10−5 kg m−2s−1 MPa−1forAcer saccharumshade leaves to 2.89 × 10−4 kg m−2 s−1 MPa−1forVitis labruscasun leaves. Tree sun leaves had 15–67% higherKlaminathan shade leaves.Klaminawas co‐ordinated with traits associated with high water flux, including leaf irradiance, petiole hydraulic conductance, guard cell length, and stomatal pore area per lamina area.Klaminawas also co‐ordinated with lamina thickness, water storage capacitance, 1/mesophyll water transfer resistance, and, in five of the six species, with lamina perimeter/area. However, for the six species,Klaminawas independent of inter‐related leaf traits including leaf dry mass per area, density, modulus of elasticity, osmotic potential, and cuticular conductance.Klaminawas thus co‐ordinated with structural and functional traits relating to liquid‐phase water transport and to maximum rates of gas exchange, but independent of other traits relating to drought tolerance and to aspects of carbon economy.
C4 photosynthesis in a single C3 cell is theoretically inefficient but may ameliorate internal CO2 diffusion limitations of C3 leaves
Authors: VON CAEMMERER S. 
Published: July 2003

ABSTRACTAttempts are being made to introduce C4 photosynthetic characteristics into C3 crop plants by genetic manipulation. This research has focused on engineering single‐celled C4‐type CO2 concentrating mechanisms into C3 plants such as rice. Herein the pros and cons of such approaches are discussed with a focus on CO2 diffusion, utilizing a mathematical model of single‐cell C4 photosynthesis. It is shown that a high bundle sheath resistance to CO2 diffusion is an essential feature of energy‐efficient C4 photosynthesis. The large chloroplast surface area appressed to the intercellular airspace in C3 leaves generates low internal resistance to CO2 diffusion, thereby limiting the energy efficiency of a single‐cell C4 concentrating mechanism, which relies on concentrating CO2 within chloroplasts of C3 leaves. Nevertheless the model demonstrates that the drop in CO2 partial pressure, pCO2, that exists between intercellular airspace and chloroplasts in C3 leaves at high photosynthetic rates, can be reversed under high irradiance when energy is not limiting. The model shows that this is particularly effective at lower intercellular pCO2. Such a system may therefore be of benefit in water‐limited conditions when stomata are closed and low intercellular pCO2 increases photorespiration.
Enzymatic control of the accumulation of verbascose in pea seeds
Authors: PETERBAUER T. , KARNER U. , MUCHA J. , MACH L. , JONES D. A. , HEDLEY C. L. , RICHTER A. 
Published: July 2003

ABSTRACTVerbascose, the pentasaccharide of the raffinose family of oligosaccharides, consists of galactose units joined to sucrose. In pea (Pisum sativum) seeds, the content of verbascose is highly variable. In a previous study on a high‐verbascose pea cultivar, the present authors have demonstrated that verbascose is synthesized by a multifunctional stachyose synthase (EC 2.4.1.67), which utilizes raffinose as well as stachyose as a galactosyl acceptor. Herein the results of a study of the cloning and functional expression of stachyose synthase from the low‐verbascose genotype SD1 are reported and it is demonstrated that this line contains a protein with a reduced ability to synthesize verbascose. Analysis of seeds from seven pea lines revealed a positive correlation between verbascose synthase activity and verbascose content. Among these genotypes, only the SD1 line showed low verbascose synthase activity when the data were normalized to stachyose synthase activity. These results suggest that differences in the level of verbascose synthase activity could be caused by mutations in the stachyose synthase gene as well as by variation in the amount of the protein. The lines were also analysed for activity of α‐galactosidase, a catabolic enzyme that could limit the extent of verbascose accumulation. No relationship was found between α‐galactosidase activity and the amount of raffinose family oligosaccharides.
TgSUB2 is a Toxoplasma gondii rhoptry organelle processing proteinase
Authors: Miller Steven A. , Thathy Vandana , Ajioka James W. , Blackman Michael J. , Kim Kami 
Published: July 2003

SummaryAll parasites in the phylum Apicomplexa, including Toxoplasma gondii and Plasmodium falciparum, contain rhoptries, specialized secretory organelles whose contents are thought to be essential for successful invasion of host cells. Serine proteinase inhibitors have been reported to block host cell invasion by both T. gondii and P. falciparum. We describe the cloning and characterization of TgSUB2, a subtilisin‐like serine proteinase, from T. gondii. Like its closest homologue P. falciparum PfSUB‐2, TgSUB2 is predicted to be a type I transmembrane protein. Disruption of TgSUB2 was unsuccessful implying that TgSUB2 is an essential gene. TgSUB2 undergoes autocatalytic processing as it traffics through the secretory pathway. TgSUB2 localizes to rhoptries and associates with rhoptry protein ROP1, a potential substrate. A sequence within TgSUB2 with homology to the ROP1 cleavage site (after Glu) was identified and mutated by site‐directed mutagenesis. This mutation abolished TgSUB2 autoprocessing suggesting that TgSUB2 is a rhoptry protein maturase with similar specificity to the ROP1 maturase. Processing of secretory organelle contents appears to be ubiquitous among the Apicomplexa. As subtilases are present in genomes of all the Apicomplexa sequenced to date, subtilases may represent a novel chemotherapeutic target.
Host plant‐dependent phenotypic reversion of Ralstonia solanacearum from non‐pathogenic to pathogenic forms via alterations in the phcA gene
Authors: Poussier Stéphane , Thoquet Philippe , Trigalet‐Demery Danièle , Barthet Séverine , Meyer Damien , Arlat Matthieu , Trigalet André 
Published: July 2003

Summary Ralstonia solanacearum is a plant pathogenic bacterium that undergoes a spontaneous phenotypic conversion (PC) from a wild‐type pathogenic to a non‐pathogenic form. PC is often associated with mutations in phcA, which is a key virulence regulatory gene. Until now, reversion to the wild‐type pathogenic form has not been observed for PC variants and the biological significance of PC has been questioned. In this study, we characterized various alterations in phcA (eight IS element insertions, three tandem duplications, seven deletions and a base substitution) in 19 PC mutants from the model strain GMI1000. In five of these variants, reversion to the pathogenic form was observed in planta, while no reversion was ever noticed in vitro whatever culture media used. However, reversion was observed for a 64 bp tandem duplication in vitro in the presence of tomato root exudate. This is the first report showing a complete cycle of phenotypic conversion/reversion in a plant pathogenic bacterium.
Staphostatins: an expanding new group of proteinase inhibitors with a unique specificity for the regulation of staphopains, Staphylococcus spp. cysteine proteinases
Authors: Rzychon Malgorzata , Sabat Artur , Kosowska Klaudia , Potempa Jan , Dubin Adam 
Published: July 2003

SummaryA novel type of cysteine proteinase inhibitor (SspC) has been recently recognized in Staphylococcus aureus (Massimi, I., Park, E., Rice, K., Muller‐Esterl, W., Sauder, D.N., and McGavin, M.J. (2002) J Biol Chem 277: 41770–41777). In this paper we have identified homologous proteins encoded in the genome of S. aureus and other coagulase‐negative Staphylococci. Collectively we refer to these proteins as staphostatins as they specifically inhibit cysteine proteinases (staphopains) from Staphylococcus spp. The primary structure of staphostatins seems to be unique, although they resemble cystatins in size (105–108 residues). Recombinant staphostatin A, a product of the scpB gene and staphostatin B (SspC) from S. aureus have been characterized in details. Similar to the cystatins, the staphostatins interact specifically with their target proteinases forming tight and stable non‐covalent complexes, staphostatin A with staphopain A and staphostatin B with staphopain B. However, in contrast to the cystatins, each of which inhibits broad range of cathepsins, complex formation between staphostatin and staphopain appears to be exclusive, with no cross interaction observed. In addition, the activities of several tested cysteine proteinases of prokaryotic‐ and eukaryotic‐origin were not affected by staphostatins. Such narrow specificity limited to staphopains is presumed to be required to protect staphylococcal cytoplasmic proteins from being degraded by prematurely activated/folded prostaphopains. This function is guaranteed through the unique co‐expression of the secreted proteinase and the intracellular inhibitor from the same operon, and represents a unique mechanism of regulation of proteolytic activity in Gram‐positive bacteria.