bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of the biotic ligand model to explain potassium interaction with thallium uptake and toxicity to plankton
Authors: Hassler Christel S. , Chafin Ryan D. , Klinger Mary Beth , Twiss Michael R. 
Published: May 2007

AbstractCompetitive interaction between Tl(I) and K was successfully predicted by the biotic ligand model (BLM) for the microalga Chlorella sp. (Chlorophyta; University of Toronto Culture Collection strain 522) during 96-h toxicity tests. Because of a greater affinity of Tl(I) (log K = 7.3–7.4) as compared to K (log K = 5.3–6.3) for biologically sensitive sites, an excess of 40-to 160-fold of K is required to suppress Tl(I) toxic effects on Chlorella sp., regardless of [Tl(I)] in solution. Similar excess of K is required to suppress Tl(I) toxicity to Synechococcus leopoliensis (Cyanobacteria; University of Texas Culture Collection strain 625) and Brachionus calyciflorus (Rotifera; strain AB-R1F). The mechanism for the mitigating effect of K on Tl(I) toxicity was investigated by measuring 204Tl(I) cellular uptake flux and efflux in Chlorella sp. Potassium shows a competitive effect on Tl(I) uptake fluxes that could be modeled using the BLM-derived stability constants and a Michaelis—Menten relationship. A strong Tl efflux dependent only on the cellular Tl concentration was measured. Although Tl efflux does not explain the effect of K on Tl(I) toxicity and uptake, it is responsible for a high turnover of the cellular Tl pool (intracellular half-life = 12–13.5 min). No effect of Na+, Mg2+, or Ca2+ was observed on Tl+ uptake, whereas the absence of trace metals (Cu, Co, Mo, Mn, Fe, and Zn) significantly increased Tl uptake and decreased the mitigating effect of K+. The importance of K+ in determining the aquatic toxicity of Tl+ underscores the use of ambient K+ concentration in the establishment of Tl water-quality guidelines and the need to consider K in predicting biogeochemical fates of Tl in the aquatic environment.
Emerging pollutants in the North Sea in comparison to Lake Ontario, Canada, data
Authors: Andresen Jens Arne , Muir Derek , Ueno Daisuke , Darling Colin , Theobald Norbert , Bester Kai 
Published: May 2007

Abstract
In the present study, the concentrations and fate of contaminants such as organophosphate flame retardants and plasticizers, musk compounds such as galaxolide (HHCB), tonalide (AHTN), musk ketone and musk xylene, the bactericide triclosan, as well as the metabolites HHCB-lactone and triclosan-methyl were compared in the aqueous phase of the German Bight (North Sea). The concentrations of these compounds were around 1 to 10 ng/L in nearshore areas, and the concentrations were lower in the more pristine areas. The highest concentrations were determined for tris-(2-chloro-isopropyl) phosphate in the North Sea with concentration exceeding 10 ng/L even for the offshore samples. The samples contained 1 to 20 ng/L chlorinated organophosphates, approximately 1 ng/L nonchlorinated organophosphates, and 0.3 to 3 ng/L fragrance compounds. Some samples from Lake Ontario (Canada) were analyzed in comparison. Per capita emissions were calculated for both regions. These emissions were compared and turned out to be very similar for the Canadian and German locations. For the North Sea, some observations concerning stability, dilution, and degradation, as well as sources of the respective substances, were performed. These data indicate that the chlorinated organophosphates and some musk fragrances exhibit half lives exceeding the residence times and thus can be considered to be persistent in this ecosystem. In the German Bight, the river Elbe is the dominating source for the more hydrophilic compounds, such as chlorinated organophosphate flame retardants, which are diluted only into the North Sea. However, for the more lipophilic compounds such as the musk fragrances, different input patterns as well as distribution patterns are relevant, though the river Elbe is still a major source of pollution to the German Bight of the North Sea. The data seem to indicate either relevant inputs further west of the sampling area or mobilization from the sediments.
Analysis of dioxins in contaminated soils with the CALUX and CAFLUX bioassays, an immunoassay, and gas chromatography/high-resolution mass spectrometry
Authors: Nording Malin , Denison Michael S. , Baston David , Persson Ylva , Spinnel Erik , Haglund Peter 
Published: May 2007

AbstractThe chemically activated luciferase expression assay, the chemically activated fluorescence expression assay, and the enzyme-linked immunosorbent assay (ELISA) are all bioanalytical methods that have been used for the detection and quantification of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). However, no comparisons of the results obtained by these three methods have been published analyzing identical replicates of purified sample extracts. Therefore, we have evaluated the performance of each of these methods for analyzing PCDD/Fs in aliquots of extracts from aged-contaminated soil samples and compared the results with those obtained by gas chromatography/high-resolution mass spectrometry (GC/HRMS). The quantitative performance was assessed and the effects of sample purification and data interpretation on the quality of the bioassay results were investigated. Results from the bioanalytical techniques were, in principle, not significantly different from each other or from the GC/HRMS data (p = 0.05). Furthermore, properly used, all of the bioanalytical techniques examined were found to be sufficiently sensitive, selective, and accurate to be used in connection with soil remediation activities when aiming at the remediation goal recommended by the U.S. Environmental Protection Agency (i.e., &lt; 1,000 pg toxic equivalency/g). However, a site-specific correction factor should be applied with the use of the ELISA to account for differences between the toxic equivalency factors and the ELISA cross-reactivities of the various PCDD/F congeners, which otherwise might significantly underestimate the PCDD/F content.
Toxicological characterization of 2,4,6-trinitrotoluene, its transformation products, and two nitramine explosives
Authors: Neuwoehner Judith , Schofer Andrea , Erlenkaemper Bibiane , Steinbach Klaus , Hund-Rinke Kerstin , Eisentraeger Adolf 
Published: May 2007

Abstract
The soil and groundwater of former ordnance plants and their dumping sites have often been highly contaminated with the explosive 2,4,6-trinitrotoluene (2,4,6-TNT) leading to a potential hazard for humans and the environment. Further hazards can arise from metabolites of transformation, by-products of the manufacturing process, or incomplete combustion. This work examines the toxicity of polar nitro compounds relative to their parent compound 2,4,6-TNT using four different ecotoxicological bioassays (algae growth inhibition test, daphnids immobilization test, luminescence inhibition test, and cell growth inhibition test), three genotoxicological assays (umu test, NM2009 test, and SOS Chromotest), and the Ames fluctuation test for detection of mutagenicity. For this study, substances typical for certain steps of degradation/transformation of 2,4,6-TNT were chosen for investigation. This work determines that the parent compounds 2,4,6-TNT and 1,3,5-trinitrobenzene are the most toxic substances followed by 3,5-dinitrophenol, 3,5-dinitroaniline and 4-amino-2-nitrotoluene. Less toxic are the direct degradation products of 2,4,6-TNT like 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-amino-4,6-dinitrotoluene, and 4-amino-2,6-dinitrotoluene. A weak toxic potential was observed for 2,4,6-trinitrobenzoic acid, 2,4-diamino-6-nitrotoluene, 2,4-dinitrotoluene-5-sulfonic acid, and 2,6-diamino-4-nitrotoluene. Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine and hexahydro-1,3,5-trinitro-1,3,5-triazine show no hint of acute toxicity. Based on the results of this study, we recommend expanding future monitoring programs of not only the parent substances but also potential metabolites based on conditions at the contaminated sites and to use bioassays as tools for estimating the toxicological potential directly by testing environmental samples. Site-specific protocols should be developed. If hazardous substances are found in relevant concentrations, action should be taken to prevent potential risks for humans and the environment. Analyses can then be used to prioritise reliable estimates of risk.
Biotransformation of caffeine, cotinine, and nicotine in stream sediments: Implications for use as wastewater indicators
Authors: Bradley Paul M. , Barber Larry B. , Kolpin Dana W. , McMahon Peter B. , Chapelle Francis H. 
Published: May 2007

Abstract
Microbially catalyzed cleavage of the imadazole ring of caffeine was observed in stream sediments collected upstream and downstream of municipal wastewater treatment plants (WWTP) in three geographically separate stream systems. Microbial demethylation of the N-methyl component of cotinine and its metabolic precursor, nicotine, also was observed in these sediments. These findings indicate that stream sediment microorganisms are able to substantially alter the chemical structure and thus the analytical signatures of these candidate waste indicator compounds. The potential for in situ biotransformation must be considered if these compounds are employed as markers to identify the sources and track the fate of wastewater compounds in surface-water systems.
RAGE polymorphisms and the heritability of insulin resistance: the Leeds Family Study
Authors: Sullivan Clair M , Futers T. Simon , Barrett Jennifer H , Hudson Barry I , Freeman Mark S , Grant Peter J 
Published: May 2007

Activation of the receptor for advanced glycation end-products (RAGE) leads to a cascade of pro-inflammatory and pro-coagulant responses which are important in the pathogenesis of the vascular complications of diabetes mellitus. It is known that pro-inflammatory mechanisms underpin the development of type 2 diabetes. Our hypothesis is that RAGE may be involved in the evolution of insulin resistance in addition to mediating glucotoxic complications of diabetes mellitus. Methods To investigate the relationship between RAGE allelic variation and insulin resistance, the Gly82Ser variant and three promoter variants (429, 374, 63 bp deletion) were studied in 480 subjects of known relationship from 89 families characterised for insulin resistance (using homeostasis model assessment [HOMA]) and for atherothrombotic risk. Carriage of the-429 C allele was weakly associated with increased insulin resistance (p=0.02) when pedigree analysis was performed using SOLAR software. Results Insulin resistance was estimated to have a heritability of 25.8% before the addition of covariates. Analysis of the relationship between RAGE and insulin resistance indicated that the-429 polymorphism reduced the unexplained heritability of insulin resistance after adjusting for covariates (age, sex, body mass index) from 17.5% of the total variance to 15.6% of the total variance. Conclusions These preliminary results indicate that the RAGE gene may affect the development of insulin resistance or be in linkage disequilibrium with a locus involved in this process.
Thiazolidinediones, peripheral oedema and congestive heart failure: what is the evidence?
Authors: Patel Chetan , Wyne Kathleen L , McGuire Darren K 
Published: May 2007

Cardiovascular disease is the most common complication of type 2 diabetes mellitus (type 2 DM), accounting for approximately 80% of deaths. While atherosclerotic vascular disease accounts for much of the cardiovascular morbidity and mortality among diabetic patients, congestive heart failure (CHF) is another key complication associated with diabetes, with an incidence three to five times greater in diabetic patients than in those without diabetes. One of the most promising developments in the treatment of type 2 DM has been the introduction of the thiazolidinedione (TZD) class of drugs, which appear to have pleiotropic effects beyond glycaemic control. Enthusiasm has been tempered, however, by concerns for safety in patients with CHF, given reports of worsening heart failure symptoms and peripheral oedema. With the growing epidemic of type 2 DM and the increasing use of TZDs, such concern has important therapeutic implications for a population of patients with a high prevalence of often subclinical systolic and diastolic dysfunction. This review provides an overview of the currently available data regarding the effects of TZDs on fluid retention and cardiac function. Particular emphasis is placed on the mechanisms of development of peripheral oedema and its significance in patients with impaired left ventricular function. TZDs are well known to cause an expansion in plasma volume; there has also been concern that TZDs may have direct toxic effects on the myocardium, leading to impaired cardiac function. Studies to date do not support this hypothesis and in fact there is growing evidence from animal models and human trials that treatment with TZDs actually improves cardiac function. There are also preclinical data to suggest TZDs may protect the myocardium in the setting of ischaemic insult or the toxic effects of myocardial lipid deposition. Ongoing clinical trials examining the use of these agents in patients at risk for heart failure will probably provide further insight into the aggregate cardiovascular effects of this promising class of medications.
Cross-sectional evaluation of the Finnish Diabetes Risk Score: a tool to identify undetected type 2 diabetes, abnormal glucose tolerance and metabolic syndrome
Authors: Saaristo Timo , Peltonen Markku , Lindström Jaana , Saarikoski Liisa , Sundvall Jouko , Eriksson Johan Gunnar , Tuomilehto Jaakko 
Published: May 2007

The aim of this study was to assess the performance of the Finnish Diabetes Risk Score as a screening tool for undetected type 2 diabetes (T2D), abnormal glucose tolerance (AGT) and metabolic syndrome in the general population. In a cross-sectional, population-based survey, a total of 4, 622 subjects aged 45–74 years were invited to a health examination that included an oral glucose tolerance test. Full data with risk score estimate and glucose tolerance status were available for 2, 966 subjects without a prior history of diabetes. The risk score was associated with the presence of previously undiagnosed T2D, AGT, metabolic syndrome and cardiovascular risk factors. The area under the receiver operating curve for the prevalence of undiagnosed diabetes was 0.72 in men and 0.73 in women. The sensitivity using a cutoff risk score of 11 to identify undiagnosed diabetes was 66% in men and 70% in women; the corresponding false-positive rates were 31% and 39%, respectively. The area under the receiver operating curve for detecting the metabolic syndrome was 0.72 in men and 0.75 in women. The Finnish Diabetes Risk Score can be used as a self-administered test to screen subjects at high risk for T2D. It can also be used in the general population and clinical practice to identify undetected T2D, AGT and the metabolic syndrome.
All obese individuals are not created equal: insulin resistance is the major determinant of cardiovascular disease in overweight/obese individuals
Authors: Reaven Gerald 
Published: May 2007

The ability of insulin to mediate glucose disposal varies more than six-fold in an apparently healthy population, and approximately one third of the most insulin-resistant of these individuals are at increased risk to develop cardiovascular disease. Differences in degree of adiposity account for approximately 25% of this variability, and another 25% varies as a function of level of physical fitness. The more overweight/obese the person, the more likely they are to be insulin-resistant and at increased risk of cardiovascular disease, but substantial numbers of overweight/obese individuals remain insulin-sensitive, and not all insulin-resistant persons are obese. Of greater clinical relevance is evidence that the metabolic benefit and decrease in risk of cardiovascular disease following weight loss occurs primarily in those overweight/obese individuals that are also insulin resistant. The relationship between insulin resistance and overall obesity, as assessed by measurement of body mass index, is essentially the same as the relationship between insulin action and abdominal obesity as quantified by determining waist circumference. Finally, there appears to be a comparable relationship between insulin-mediated glucose disposal and amount of visceral fat, subcutaneous fat, and total fat as quantified by various imaging techniques, and the magnitude of these relationships is no greater than that between insulin action and simple measure of body mass index.
Biomarkers in acute coronary syndromes and their role in diabetic patients
Authors: Heeschen Christopher 
Published: May 2007

Diabetic patients with acute coronary syndromes are at high risk for cardiovascular complications but risk stratification in these patients remains challenging. Regularly, diabetic patients have a less typical clinical presentation, which could lead to delayed diagnosis and subsequent delayed initiation of treatment. Since diabetic patients derive particular benefit from aggressive anti-platelet therapy, early diagnostic and therapeutic risk stratification of these patients is of critical importance to improve their adverse outcome. Although the electrocardiogram remains a pivotal diagnostic tool in the evaluation of patients suspected of having an acute coronary syndrome, only significant ST-segment changes provide reasonable prognostic information. Therefore, repeated assessment of circulating protein biomarkers represents a valuable diagnostic tool for improving efficacy and safety of decision-making in these patients. The combined use of biomarkers reflecting distinct pathophysiological aspects, such as myocardial necrosis, vascular inflammation, oxidative stress and neurohumoral activation, may significantly improve triage of patients with chest pain. These tools may identify those patients that are at particularly high risk for short-term and/or long-term cardiovascular events. Eventually, tailored medical and interventional treatment of diabetic patients should help to prevent these cardiac events in a cost-effective manner.
Success rates of percutaneous coronary intervention of chronic total occlusions and long-term survival in patients with diabetes mellitus
Authors: Safley David M , House John A , Rutherford Barry D , Marso Steven P 
Published: May 2007

The objectives of this study were to evaluate angiographic and clinical outcomes among patients with diabetes mellitus (DM) who underwent percutaneous coronary intervention (PCI) for a chronic total occlusion (CTO). We compared them with matched patients undergoing PCI of a non-CTO lesion. All patients had documented DM. Matching was performed using a propensity score for CTO. There were 506 patients with DM and CTO who were matched with a non-CTO group. Results showed that angiographic success rates were lower with CTO (75% vs. 93%, p<0.001). In-hospital major adverse cardiac event (MACE Â death, urgent bypass surgery, Q-wave myocardial infarction or target vessel revascularisation) rates were equivalent (CTO 3.2% vs. non-CTO 2.6%, p=0.57). Survival was not different five years after revascularisation of CTO (75%) vs. non-CTO (79%) (p=0.20). In addition, when DM patients with CTO were analysed according to angiographic success of PCI, there were no significant differences in either in-hospital (success 1.6% vs. failure 2.4%, p=0.7) or 1-year mortality (success 22.2% vs. failure 26.8%, p=0.3). We conclude that PCI of CTO is safe in patients with DM. Angiographic failure is not associated with an increase in MACE rates or mortality as compared to matched nonCTO patients. However, there is not a measurable improvement in survival in this DM-CTO population.
Risk factors for stroke in type 2 diabetes mellitus
Authors: Asfandiyarova Nailya , Kolcheva Nina , Ryazantsev Igor , Ryazantsev Vladimir 
Published: May 2007

Stroke is a serious complication of diabetes but the risk factors for stroke in these patients are not fully defined. The aim of this retrospective study was to investigate the risk factors for stroke in patients with type 2 diabetes mellitus (T2DM). The group comprised 208 patients with T2DM, and the mean duration of follow-up was seven years (range 4–11 years). The incidence of stroke was investigated according to lymphocyte proliferation in response to insulin. Using cimetidine to inhibit cells with histamine receptors and indometacin to inhibit prostaglandin-synthesising cells, a higher incidence of stroke was found in patients with indirect cell-mediated immunity to insulin. Therefore, one of the risk factors for stroke in patients with T2DM is high activity of cells with histamine receptors and prostaglandin-synthesising cells. These cells suppress cell-mediated immunity to insulin and may have a role in promoting the development of insulin resistance.
Reducing residual cardiovascular risk: the relevance of raising high-density lipoprotein cholesterol in patients on cholesterol-lowering treatment
Authors: Pedersen Terje R , Assmann Gerd , Bassand Jean-Pierre , Chapman M John , Erbel Raimund , Sirtori Cesare 
Published: May 2007

Reducing low-density lipoprotein cholesterol (LDL-C) with statin therapy represents the cornerstone of dyslipidaemia management in patients with cardiovascular disease, as reflected in current treatment guidelines. Yet even among statin-treated patients who achieve LDL-C targets (< 2.59 mmol/L [100 mg/dL]), the residual risk of further cardiovascular events remains unacceptably high. Although clinical studies indicate that intensive LDL-C lowering may provide some additional benefit, this does not suppress the excess cardiovascular risk sufficiently. This European Expert Panel therefore recognises that there is an unmet clinical need in the management of these patients. Additional intervention to modify other clinically important risk factors should be viewed as a priority. A reduced level of high-density lipoprotein cholesterol (HDL-C) < 1.03 mmol/L (40 mg/dL) in men and < 1.29 mmol/L (50 mg/dL) in women is an important independent predictive factor for coronary heart disease. HDL-C levels are also predictive of cardiovascular risk in statin-treated patients, irrespective of their LDL-C levels. Therefore, HDL-C represents a logical therapeutic target for reducing cardiovascular risk further in statin-treated patients, including those who achieve LDL-C targets. Given that low HDL-C is common among dyslipidaemic patients with cardiovascular disease, a therapeutic strategy aimed at effectively raising HDL-C, while at the same time lowering LDL-C to target levels, would be expected to offer clinical benefit beyond that achieved through LDL-C reduction alone. Although both nicotinic acid and fibrates raise HDL-C, nicotinic acid has greater potency. Studies show that combination therapy with prolonged-release (PR) nicotinic acid and a statin has an acceptable tolerability profile, normalises an atherogenic lipoprotein profile, and is able to induce regression of atherosclerosis and reduce coronary risk in patients with established cardiovascular disease and suboptimal HDL-C levels. In conclusion, this European Expert Panel recommends that combination therapy with a statin and an HDL-C raising agent, such as PR nicotinic acid, should be considered in these patients, who remain at high residual risk despite achieving target LDL-C levels with statin monotherapy. Ongoing studies are essential to confirm the clinical outcome benefits of this approach.