bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of selenium on thioredoxin reductase activity in Txnrd1 or Txnrd2 hemizygous mice
Authors: Kiermayer Claudia , Michalke Bernhard , Schmidt Jörg , Brielmeier Markus 
Published: October 2007

Abstract
Thioredoxin reductase 1 (Txnrd1) and thioredoxin reductase 2 (Txnrd2) are selenoproteins whose expression and function depends on adequate supply of the trace element selenium (Se). As homozygous (-/-) knockout of both Txnrd1 and Txnrd2 is embryonically lethal, we investigated the effect of their hemizygosity (+/-) alone and in combination with dietary Se on enzymatic activity in various tissues. To assess the overall health of the corresponding mice, the growth, viability and fertility of the different experimental groups were also compared. Se depletion led to a marked decrease in Se organ contents. Se depletion was most prominent in lung, followed by liver, kidney, heart, muscle and brain. We found no major effect of Txnrd1 or Txnrd2 hemizygosity and/or Se on male fertility and the viability of offspring. A gene dose effect under Se-adequate conditions for Txnrd1 and Txnrd2 in all organs was observed. Haploid insufficiency decreased Txnrd activity to an extent that can be further decreased by Se deficiency, but not to levels below those observed for Se depletion alone. The only exception was Txnrd2 activity in kidney, heart and muscle, where we found an additive effect.
Defects in homocysteine metabolism: diversity among hyperhomocyst(e)inemias
Authors: Matthews Rowena G. , Elmore C. Lee 
Published: October 2007

AbstractThere are now four genetic mouse models that induce hyperhomocyst(e)inemia by decreasing the activity of an enzyme involved in homocysteine metabolism: cystathionine β-synthase, methylenetetrahydrofolate reductase, methionine synthase and methionine synthase reductase. While each enzyme deficiency leads to murine hyperhomocyst(e)inemia, the accompanying metabolic profiles are significantly and often unexpectedly, different. Deficiencies in cystathionine β-synthase lead to elevated plasma methionine, while deficiencies of the remaining three enzymes lead to hypomethioninemia. The liver [S-adenosylmethionine]/[S-adenosylhomocysteine] ratio is decreased in mice lacking methylenetetrahydrofolate reductase or cystathionine β-synthase, but unexpectedly increased in mice with deficiencies in methionine synthase or methionine synthase reductase. Folate pool imbalances are observed in complete methylenetetrahydrofolate reductase deficiency, where methyltetra-hydrofolate is a minor component, and in methionine synthase reductase deficiency, where methyltetrahydrofolate is increased relative to wild-type mice. These differences illustrate the potential diversity among human patients with hyperhomocyst(e)inemia, and strengthen the argument that the pathologies associated with the dissimilar forms of the condition will require different treatments.Clin Chem Lab Med 2007;45:1700–3.
Homocysteine-lowering vitamin B treatment decreases cardiovascular events in hemodialysis patients
Authors: Righetti Marco 
Published: October 2007

AbstractIn Italy, the mortality rate of hemodialysis patients is approximately 14% per year. Cardiovascular disease is the most important cause of morbidity and mortality in hemodialysis patients. High plasma homocysteine levels are commonly detected in these patients, but hyperhomocysteinemia and cardiovascular mortality are not always strictly correlated. The Dialysis Outcomes and Practice Pattern Study (DOPPS) showed a direct association between regular use of water-soluble vitamins and lower cardiovascular mortality. We recently performed a long-term prospective trial to study the effects of folic acid therapy on cardiovascular events in hemodialysis patients. We observed not only a lower rate of combined cardiovascular events in patients treated with folate, but also a direct correlation between hyperhomocysteinemia and cardiovascular morbidity. On the contrary, the distribution of deaths was similar in treated and untreated patients, because, almost certainly, sudden death is not always due to atherosclerotic events, and non-cardiovascular deaths, such as cachexia, septicemia and malignancy were characterized by low levels of homocysteine, which may be, in addition, a nutritional index similar to albumin and protein catabolic rate. As it is known that diabetic hemodialysis patients have a higher mortality rate, but lower homocysteine levels as compared to non-diabetic patients, we performed an equal allocation of diabetic patients in treated and untreated groups. We observed a similar homocysteine reduction rate in diabetic patients as compared to non-diabetic patients, and a trend towards a lower rate of composite cardiovascular events in treated diabetic patients as compared to untreated diabetic patients. To summarize, the strong relationship between homocysteine and nutritional, inflammatory markers may hide its association with cardiovascular disease. Homocysteine-lowering vitamin B therapy may lower cardiovascular events in dialysis patients. It is mandatory to perform large prospective trials to confirm our results.Clin Chem Lab Med 2007;45:1586–9.
Homocysteine and asymmetric dimethylarginine (ADMA): biochemically linked but differently related to vascular disease in chronic kidney disease
Authors: van Guldener Coen , Nanayakkara Prabath W.B. , Stehouwer Coen D.A. 
Published: October 2007

AbstractAsymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is formed by methylation of arginine residues in proteins and released after proteolysis. In this reaction, S-adenosylmethionine is methyldonor and S-adenosylhomocysteine the demethylated product. ADMA and homocysteine are thus biochemically linked. Both plasma homocysteine and ADMA concentrations are increased in patients with renal dysfunction, probably as a result of an impairment in their metabolic, but not urinary, clearance. Hyperhomocysteinemia has been associated with an increased risk of cardiovascular disease in end-stage renal disease, especially in patients without malnutrition and inflammation. Also, plasma ADMA levels have been associated with cardiovascular disease in renal failure patients. Both homocysteine and ADMA are thought to mediate their adverse vascular effects by impairing endothelial, nitric oxide-dependent function resulting in decreased vasodilatation, increased smooth muscle cell proliferation, platelet dysfunction and increased monocyte adhesion. At the same time, it has been shown that the correlation between plasma ADMA and homocysteine is weak and that, in renal patients, the association of plasma ADMA carotid intima-media thickness, cardiovascular events and overall mortality is independent of homocysteine. This indicates that the negative vascular effects of ADMA and homocysteine have a different etiology. Treatment with folic acid substantially lowers homocysteine, but not ADMA concentration. So far, homocysteine-lowering therapy has not been very successful in decreasing cardiovascular disease. In patients with renal failure, ADMA reduction may be an interesting new goal in the prevention of cardiovascular disease.Clin Chem Lab Med 2007;45:1683–7.
Exploring image schemas as a critical concept: Toward a critical-cognitive linguistic account of image-schematic interactions
Authors: Tseng Ming-Yu 
Published: October 2007

Abstract
This article aims to advance the study of “image schemas” by drawing on insights not only from cognitive linguistics but also from critical linguistics. It highlights five specific features possessed by “image schemas”: (1) their serving as a bridge between concrete, sensorimotor experience and abstract reasoning; (2) their being emergent patterns created and evoked when people engage in understanding language; (3) their function of superimposition (i. e. interactions among image schemas); (4) their insinuation of a plus-minus parameter (i. e. the tendency of the opposing parts of an image schema to be more positively or negatively valued); and (5) their static and dynamic nature. It will also briefly address how image schemas, metaphors and socio-cultural values are entwined. The critical-cognitive perspective calls for the view of “situated” image schemas in discourse. By way of illustration, I will analyze two Chinese Zen poems. The analysis will pay special attention to imageschematic patterns and their significance in the interface between discourse, cognition, and worldview.
The expressive dimension
Authors: Potts Christopher 
Published: October 2007

Abstract
Expressives like damn and bastard have, when uttered, an immediate and powerful impact on the context. They are performative, often destructively so. They are revealing of the perspective from which the utterance is made, and they can have a dramatic impact on how current and future utterances are perceived. This, despite the fact that speakers are invariably hard-pressed to articulate what they mean. I develop a general theory of these volatile, indispensable meanings. The theory is built around a class of expressive indices. These determine the expressive setting of the context of interpretation. Expressive morphemes act on that context, actively changing its expressive setting. The theory is multidimensional in the sense that descriptives and expressives are fundamentally different but receive a unified logical treatment.
Re-expressing judgment
Authors: Anand Pranav 
Published: October 2007

Abstract
Potts (this issue) claims that non-speaker-oriented expressive content may be handled by the introduction of an expressive judge to the context. Given both that expressives may express sentiments temporally and modally displaced from the utterance and that there may be multiple expressive judges per sentence, I argue that a unitary judge is insuffcient, and suggest that non-speaker-oriented expressives are more directly captured as a species of partial quotation.
Really fucking brilliant
Authors: Geurts Bart 
Published: October 2007

Abstract
The title of this note has a two-tiered interpretation. On the “use” level, it expresses my admiration for the ingenuity and elegance of Christopher Potts's paper, which is not diminished by the fact that I disagree with him practically across the board. On the “mention” level, my title denotes the key phrase in Potts's example (2), which will figure rather prominently in the following remarks.
Expressives, perspective and presupposition
Authors: Lasersohn Peter 
Published: October 2007

Abstract
I compare Potts' use of a “judge” parameter in semantic interpretation with the use of a similar parameter in Lasersohn (2005). The latter technique portrays the content of expressives as constant across speakers, while Pott's technique does not. The idea that the content of expressives is a kind of presupposition is also briefly defended, and a technical problem in the “dynamics” of Pott's formalism is pointed out.
Beyond unpluggability
Authors: Sauerland Uli 
Published: October 2007

Abstract
Emotional expressions like damn and bastard seem to bring out the extreme not only in the speakers who use them, but also in the linguists who try to account for them: For Potts, nothing short of a new dimension of meaning can accommodate these expressions. Potts already in earlier work (Potts, 2003) provides one interesting argument for this view: the unpluggability (or nondisplaceability) of these expressions in many cases. Regardless of the position and level of embedding that that damn bastard John occurs in in a sentence, the speaker uttering such a sentence conveys that he, the speaker, does not think all too highly of John. In the present work, Potts still tries to maintain the core of his earlier theory, but slightly retreats from his earlier position accepting examples due to Kratzer and Schlenker where unpluggability is not observed. Potts' interesting work raises two related questions from my perspective: 1) What is the best account for the unpluggability of expressive content? and 2) Is expressive content a uniform phenomenon?
I like that damn paper – Three comments on Christopher Potts' The expressive dimension
Authors: Zimmermann Malte 
Published: October 2007

Abstract

1. Introduction

Christopher Potts has put forward a precise formal analysis of the semantics of expressives, which accounts for their characteristic properties quite well, and which will certainly further our understanding of these expressions. In this short reaction, I concentrate on three aspects where – I think – the proposed analysis of expressives is in need of refinement, or where it is in need of complementation. The three aspects concern (i) the suggested non-accessibility of expressive content to the descriptive meaning dimension; (ii) the internal structure of expressive indices and the nature of index-changing operations; (iii) and the semantic behavior of discourse particles in relation to expressives proper.
Behavioral Discrimination between Sucrose and Other Natural Sweeteners in Mice: Implications for the Neural Coding of T1R Ligands
Authors: Dotson Cedrick D. , Spector Alan C. 
Published: October 2007

In taste bud cells, two different T1R heteromeric taste receptors mediate signal transduction of sugars (the canonical “sweet” taste receptor, T1R2 + T1R3) andl-amino acids (the T1R1 + T1R3 receptor). The T1R1 + T1R3 receptor is thought to mediate what is considered the fifth basic taste quality “umami.” However, a subset ofl-amino acids is “sweet tasting” to humans and appears to possess a “sucrose-like” taste quality to nonhuman mammals. This suggests, to varying degrees, that all of these compounds activate a single neural channel that leads to the perception of sweetness.The experiments detailed here were designed to test the ability of mice to distinguish between sucrose and various others sugars andl-amino acids in operant taste discrimination tasks. Mice had at least some difficulty discriminating sucrose froml-serine,l-threonine, maltose, fructose, and glucose. For example, when concentration effects are taken into consideration, mice discriminated poorly, if at all, sucrose from glucose or fructose and, to a lesser extent maltose, suggesting that sugars generate a unitary perceptual quality. However, mice were able to reliably discriminate sucrose froml-serine andl-threonine. Data gathered using a conditioned taste aversion assay also suggest that, although qualitatively similar to the taste of sucrose,l-serine andl-threonine generate distinctive percepts.In conclusion, it appears that some signals from taste receptor proteins binding with sugars and somel-amino acids converge somewhere along the gustatory neuraxis. However, the results of these experiments also imply that sweet-tastingl-amino acids may possess qualitative taste characteristics that are distinguishable from the prototypical sweetener sucrose.
Methyl-tert-hexyl ether and methyl-tert-octyl ether as gasoline oxygenates: Anticipating widespread risks to community water supply wells
Authors: Snelling Jeff , Barnett Mark O. , Zhao Dongye , Arey J. Samuel 
Published: October 2007

Abstract
The widespread contamination of groundwater resources associated with methyl-tert-butyl ether (MtBE) use has prompted a search for replacement oxygenates in gasoline. Among the alternatives currently under development are higher methyl-tert-alkyl ethers, notably methyl-tert-hexyl ether (MtHxE) and methyl-tert-octyl ether (MtOcE). As was the case with MtBE, the introduction of these ethers into fuel supplies guarantees their migration into groundwater resources. In the present study, a screening-level risk assessment compared predicted well water concentrations of these ethers to concentrations that might cause adverse effects. A physicochemical model which has been successfully applied to the prediction of MtBE concentrations in community water supply wells (CSWs) was used to predict well water concentrations of MtHxE and MtOcE. The results indicate that these ethers are likely to contaminate water supply wells at slightly lower levels than MtBE as a result of migrating from leaking underground fuel tanks to CSWs. Because very little data is available on the physicochemical and environmental properties of MtHxE and MtOcE, estimation methods were employed in conjunction with the model to predict well water concentrations. Model calculations indicated that MtHxE and MtOcE will be present in many CSWs at concentrations approaching the concentrations that have caused widespread public health concern for MtBE. Based on these results and the possibility that MtHxE and MtOcE are potential carcinogens, testing of the toxicological properties of these ethers is recommended before they are used to replace MtBE in gasoline.
Estrogen-like properties of perfluorooctanoic acid as revealed by expressing hepatic estrogen-responsive genes in rare minnows (Gobiocypris rarus)
Authors: Wei Yanhong , Dai Jiayin , Liu Min , Wang Jianshe , Xu Muqi , Zha Jinmiao , Wang Zijian 
Published: October 2007

AbstractPerfluorooctanoic acid (PFOA) is an important perfluorinated compound (PFC) with various applications and has been widely disseminated in the environment, wildlife, and humans. The present study investigated the effects of waterborne PFOA on the expression of hepatic estrogen-responsive genes, vitellogenin (VTG), and estrogen receptor β (ERβ) and on the gonadal development in a freshwater rare minnow (Gobiocypris rarus). The mRNA levels of VTG and ERβ were determined using reverse transcription polymerase chain reaction (RT-PCR) techniques, and VTG protein levels were identified using enzyme-linked immunosorbent assay. A significant increase of VTG expression in the livers of both mature males and females was observed after 14 and 28 d of exposure to 3, 10, and 30 mg/L PFOA, indicating that PFOA could induce VTG synthesis. The expression of ERβ increased significantly in livers of both mature males and females after a 14-d exposure, although no difference was observed after a 28-d exposure. The development of oocytes in testes exposed to PFOA also provided evidence of estrogenic activity in males. The ovaries of PFOA-exposed females underwent degeneration, as reported in other fish species exposed to environmental estrogens. This preliminary study indicates that PFOA can disturb the activity of estrogen in mature male rare minnows by inducing hepatic estrogen-responsive genes, VTG and ERβ, and barrier female reproduction.
Metabolic fate of [14C]-2,4-dichlorophenol in tobacco cell suspension cultures
Authors: Laurent Francois , Canlet Cécile , Debrauwer Laurent , Pascal-Lorber Sophie 
Published: October 2007

AbstractIn plant tissues, xenobiotics often are conjugated with natural constituents such as sugars, amino acids, glutathione, and malonic acid. Usually, conjugation processes result in a decrease in the reactivity and toxicity of xenobiotics by increasing the water solubility and polarity of conjugates, and reducing their mobility. Due to their lack of an efficient excretory system, xenobiotic conjugates finally are sequestered in plant storage compartments or cell vacuoles, or are integrated as bound residues in cell walls. Chlorophenols are potentially harmful pollutants that are found in numerous natural and agricultural systems. we studied the metabolic fate of 2,4-dichlorophenol (DCP) in cell-suspension cultures of tobacco (Nicotiana tabacum L.). After a standard metabolism experiment, 48h of incubation with a [U-phenyl-14C]-DCP solution, aqueous extracts of cell suspension cultures were analyzed by high-performance liquid chromatography (HPLC). Metabolites then were isolated and their chemical structures determined by enzymatic and chemical hydrolyses, electrospray ionization-mass spectrometry in negative mode (ESI-NI), and 1H nuclear magnetic resonance analyses. The main terminal metabolites identified were DCP-glycoside conjugates, DCP-(6-O-malonyl)-glucoside, DCP-(6-O-acetyl)-glucoside, and their precursor, DCP-glucoside. More unusual and complex DCP conjugates such as an α(1→6)-glucosyl-pentose and a triglycoside containing a glucuronic acid were further characterized. All the metabolites identified were complex glycoside conjugates. However, these conjugates still may be a source of DCP in hydrolysis reactions caused by microorganisms in the environment or in the digestive tract of animals and humans. Removal of xenobiotics by glycoside conjugation thus may result in underestimation of the risk associated with toxic compounds like DCP in the environment or in the food chain.
Application of the target lipid model for deriving predicted no-effect concentrations for wastewater organisms
Authors: Redman Aaron , McGrath Joy , Febbo Eric , Parkerton Thomas , Letinski Dan , Connelly Martin , Winkelmann Douglas , Toro Dominic Di 
Published: October 2007

AbstractThe target lipid model (TLM) was applied to literature data from 10 microbial toxicity assays to provide a quantitative effects assessment framework for wastewater treatment plant organisms. For the nonpolar organic chemicals considered, linear relationships between the logarithm of the median effect concentrations (EC50) and log(KOW) conformed to the TLM for all endpoints with the exception of nitrification inhibition. Additional experimental data for the nitrification inhibition endpoint were generated for 16 narcotic chemicals using a procedure that allowed testing of volatile substances. Results obtained from the present study demonstrated that the nitrification inhibition endpoint was not adequately described by the TLM consistent with previous literature data. Acute to chronic ratios (ACRs) defined as the ratio of the EC50 to the 10% effect concentration (EC10) were available for two of the endpoints investigated and ranged from 1.1 to 2.3 for the Tetrahymena growth assay and from 2.4 to 24.1 for the nitrification inhibition endpoint. No inhibitory effects for any of the microbial endpoints investigated were observed for compounds with log(KOW) &gt; 5. The critical target lipid body burdens (CL*) were calculated for the nine microbial toxicity endpoints conforming to the TLM and ranged from 252 to 2,250 μmol/g octanol. The Microtox® light inhibition (CL* = 252 μmol/g octanol) and Tetrahymena pyriformis growth (CL* = 254 μmol/g octanol) assays were found to be the most sensitive endpoints. The predicted no-effect concentration (PNEC) derived using the HC5 (hazardous concentration to 5% of test organisms) statistical extrapolation procedure was calculated using TLM parameters for substances with log(KOW) from 0 to 5. Results from this analysis demonstrate PNECs for narcotic compounds are protective of wastewater organisms excluding nitrifying bacteria. Further model improvement is needed if protection of nitrifying bacteria in wastewater treatment systems is required.