bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evidence for the involvement of SDF-1 and CXCR4 in the disruption of endothelial cell-branching morphogenesis and angiogenesis by TNF-α and IFN-γ
Authors: Salvucci Ombretta , Basik Mark , Yao Lei , Bianchi Rossella , Tosato Giovanna 
Published: April 2004

AbstractVigorous inflammatory responses are associated with tissue damage, particularly when toxic levels of inflammatory cytokines are produced. Despite proangiogenic factors being present early at sites of inflammation, vascular repair occurs toward the end of the inflammatory response, suggesting modulation of the proangiogenic response. Endogenous inhibitors of angiogenesis induced during acute inflammation are poorly characterized. Here, we looked for endothelial cell-derived modulators of angiogenesis that may account for delayed neovascularization during inflammation. Gene profiling of endothelial cells showed that the inflammatory cytokines tumor necrosis factor α (TNF-α) and interferon-γ (IFN-γ) selectively promote expression of the antiangiogenic molecules, IFN-inducible protein-10, monokine induced by IFN-γ, tryptophanyl-tRNA synthetase, and tissue inhibitor of metalmetalloproteinase-1, and inhibit expression of the proangiogenic molecules, platelet-endothelial cell adhesion molecule-1, vascular endothelial growth factor receptor-2, stromal cell-derived factor-1 (SDF-1), collagen type IV, endothelial cell growth factor-1, and carcinoembryonic antigen-related cell adhesion molecule-1. Reduced endothelial cell expression of SDF-1 protein by TNF-α and IFN-γ disrupts extracellular matrix-dependent endothelial cell tube formation, an in vitro morphogenic process that recapitulates critical steps in angiogenesis. Replacement of SDF-1 onto the endothelial cell surface reconstitutes this morphogenic process. In vivo, TNF-α and IFN-γ inhibit growth factor-induced angiogenesis and SDF-1 expression in endothelial cells. These results demonstrate that SDF-1/CXC chemokine receptor-4 constitutes a TNF-α- and IFN-γ-regulated signaling system that plays a critical role in mediating angiogenesis inhibition by these inflammatory cytokines.
A teacher-verification study of speaking and writing prototype tasks for a new TOEFL
Authors: Cumming Alister , Grant Leslie , Mulcahy-Ernt Patricia , Powers Donald E. 
Published: April 2004

This study was undertaken, in conjunction with other studies eld-testing prototype tasks for a new TOEFL, to evaluate the content validity, perceived authenticity and educational appropriateness of these prototype tasks. We interviewed seven highly experienced instructors of English as a Second Language (ESL) at three universities, asking them to rate their students’ abilities in English and to review samples of their students’ performance to determine whether they thought seven prototype speaking and writing tasks being eld-tested for a new version of the TOEFL® test: • represented the domain of academic English required for studies at English-medium universities or colleges in North America; • elicited performance from their adult ESL students that corresponded to their usual performance in ESL classes and course assignments; and • realized the evidence claims on which the tasks had been designed. The instructors thought that most of their students’ performances on the prototype test tasks were equivalent to or better than their usual performance in classes. The instructors viewed positively the new prototype tasks that required students to write or to speak in reference to reading or listening source texts, but they observed certain problems with these novel tasks and suggested ways that their content and presentation might be improved for the formative development of these tasks.
Diurnal Rhythm of Apolipoprotein A-IV in Rat Hypothalamus and Its Relation to Food Intake and Corticosterone
Authors: Liu Min , Shen Ling , Liu Yin , Tajima Daisuke , Sakai Randall , Woods Stephen C. , Tso Patrick 
Published: April 2004

AbstractApolipoprotein A-IV (apo A-IV) is a satiety protein synthesized in the small intestine and hypothalamus. To further understand the roles of central apo A-IV in the management of daily food intake, we have examined the diurnal patterns of hypothalamic apo A-IV gene and protein expression in freely feeding and food-restricted (food provided 4 h daily between 1000 h and 1400 h) rats. In freely feeding rats, the hypothalamic apo A-IV mRNA and protein levels fluctuated, with high levels during the light phase, peaking at 0900 h (3 h after lights on), and low levels during the dark phase, with a nadir at 2100 h (3 h after lights off). The daily patterns of the fluctuation, however, were altered in food-restricted rats, which had a marked decrease in hypothalamic apo A-IV mRNA and protein levels during the 4 h-feeding period of the light phase. Although corticosterone (CORT) secretion temporally coincided with the decreasing phase of apo A-IV in the hypothalamus, depletion of CORT by adrenalectomy significantly decreased, rather than increased, hypothalamic apo A-IV mRNA and protein levels. These results indicate that the diurnal expression of hypothalamic apo A-IV is regulated by factors other than the circulating CORT, for example, the reduced food intake and body weight in adrenalectomized animals. The fact that hypothalamic apo A-IV level and food intake were inversely related during the normal diurnal cycle as well as in the period of restricted feeding suggests that hypothalamic apo A-IV is involved in the regulation of daily food intake.
Body Mass Index and C-174G Interleukin-6 Promoter Polymorphism Interact in Predicting Type 2 Diabetes
Authors: Möhlig Matthias , Boeing Heiner , Spranger Joachim , Osterhoff Martin , Kroke Anja , Fisher Eva , Bergmann Manuela M. , Ristow Michael , Hoffmann Kurt , Pfeiffer Andreas F. H. 
Published: April 2004

Abstract
Increased levels of IL-6 add further risk to the impact of obesity in respect to the development of type 2 diabetes mellitus (T2DM). A C-174G polymorphism within the IL-6 promoter region was shown to influence transcription rate of IL-6. We made use of a nested case-control study within the European Prospective Investigation into Cancer and Nutrition-Potsdam cohort of 27,548 individuals, selecting 188 T2DM cases and 376 controls to investigate this polymorphism in respect to development of T2DM. This polymorphism was found to modify the correlation between body mass index (BMI) and IL-6 by showing a much stronger increase of IL-6 at increased BMI for CC genotypes compared with GG genotypes. Interestingly, C-174G polymorphism was found to be an effect modifier for the impact of BMI regarding T2DM. Whereas BMI greater than or equal to 28 kg/m2 increased the risk of T2DM 3.44-fold [95% confidence interval (CI), 1.34- to 8.24-fold] for GG genotypes and 2.94-fold (95% CI, 1.56- to 5.56-fold) for GC genotypes, we found a 17.68-fold (95% CI, 3.57- to 87.66-fold) increase in risk for CC genotypes. In conclusion, obese individuals with BMI greater than or equal to 28 kg/m2 carrying the CC genotype showed a more than 5-fold increased risk of developing T2DM compared with the remaining genotypes and, hence, might profit most from weight reduction.
Analysis of Antibody Reactivity against Cysteine Sulfinic Acid Decarboxylase, A Pyridoxal Phosphate-Dependent Enzyme, in Endocrine Autoimmune Disease
Authors: Sköldberg Filip , Rorsman Fredrik , Perheentupa Jaakko , Landin-Olsson Mona , Husebye Eystein S. , Gustafsson Jan , Kämpe Olle 
Published: April 2004

Abstract
The structurally related group II pyridoxal phosphate (PLP)-dependent amino acid decarboxylases glutamic acid decarboxylase (GAD), aromatic l-amino acid decarboxylase (AADC), and histidine decarboxylase (HDC) are known autoantigens in endocrine disorders. We report, for the first time, the prevalence of serum autoantibody reactivity against cysteine sulfinic acid decarboxylase (CSAD), an enzyme that shares 50% amino acid identity with the 65- and 67-kDa isoforms of GAD (GAD-65 and GAD-67), in endocrine autoimmune disease. Three of 83 patients (3.6%) with autoimmune polyendocrine syndrome type 1 (APS1) were anti-CSAD positive in a radioimmunoprecipitation assay. Anti-CSAD antibodies cross-reacted with GAD-65, and the anti-CSAD-positive sera were also reactive with AADC and HDC. The low frequency of anti-CSAD reactivity is in striking contrast to the prevalence of antibodies against GAD-65, AADC, and HDC in APS1 patients, suggesting that different mechanisms control the immunological tolerance toward CSAD and the other group II decarboxylases. Moreover, CSAD may be a useful mold for the construction of recombinant chimerical antigens in attempts to map conformational epitopes on other group II PLP-dependent amino acid decarboxylases.
Relationship between Serum Resistin Concentrations and Insulin Resistance in Nonobese, Obese, and Obese Diabetic Subjects
Authors: Heilbronn L. K. , Rood J. , Janderova L. , Albu J. B. , Kelley D. E. , Ravussin E. , Smith S. R. 
Published: April 2004

Abstract
Early reports suggested that resistin is associated with obesity and insulin resistance in rodents. However, subsequent studies have not supported these findings. To our knowledge, the present study is the first assessment in human subjects of serum resistin and insulin sensitivity by the insulin clamp technique. Thirty-eight nonobese subjects [age, 23 ± 4 yr; body mass index (BMI), 25.4 ± 4.3 kg/m2], 12 obese subjects (age, 54 ± 8 yr; BMI, 33.0 ± 2.5 kg/m2), and 22 obese subjects with type 2 diabetes (age, 59 ± 7 yr; BMI, 34.0 ± 2.4 kg/m2) were studied. Serum resistin concentrations were not different among nonobese (4.1 ± 1.7 ng/ml), obese (4.2 ± 1.6 ng/ml), and obese diabetic subjects (3.7 ± 1.2 ng/ml), and were not significantly correlated to glucose disposal rate during a hyperinsulinemic glucose clamp across groups. Serum resistin was, however, inversely related to insulin sensitivity in nonobese subjects only (r = −0.35; P = 0.05), although this association was lost after adjusting for percent body fat. Serum resistin was not related to percent fat, BMI, or fat cell size. A strong correlation was observed between serum resistin and resistin mRNA expression from abdominal sc adipose tissue in a separate group of obese subjects (r = 0.62; P &lt; 0.01; n = 56). Although the exact function of resistin is unknown, we demonstrated only a weak relationship between resistin and insulin sensitivity in nonobese subjects, indicating that resistin is unlikely to be a major link between obesity and insulin resistance in humans.
The Effects of Age and Other Variables on Serum Parathyroid Hormone in Postmenopausal Women Attending an Osteoporosis Center
Authors: Need Allan G. , O’Loughlin Peter D. , Morris Howard A. , Horowitz Michael , Nordin B. E. Christopher 
Published: April 2004

Abstract
It has been known for many years that serum PTH rises with age, and it has been suggested that this rise may contribute to bone loss in postmenopausal women. It has been variously attributed to declining renal function, declining calcium absorption efficiency, and declining serum 25-hydroxyvitamin D [25(OH)D] levels.
We studied the effects of age, weight, renal function, radiocalcium absorption, serum ionized calcium, and serum 25(OH)D on serum PTH levels in 918 postmenopausal women attending an osteoporosis center. On simple linear regression, serum PTH was a positive function of age (P = 0.003) and weight (P &lt; 0.001) and an inverse function of serum 25(OH)D (P &lt; 0.001) and serum ionized calcium (P = 0.002). On stepwise regression, serum 25(OH)D was the most significant (negative) determinant of serum PTH, followed in decreasing order of significance by serum ionized calcium (negative) and body weight and age (positive). Serum PTH was not related to radiocalcium absorption. The reciprocal relation between serum PTH and serum 25(OH)D could not be explained by the serum concentration of 1,25-dihydroxyvitamin D, which did not change with age. After adjustment for serum ionized calcium, body weight, and age, the rise in serum PTH appeared to start when serum 25(OH)D fell less than 80 nmol/liter.
Effect of Aldosterone and Glycyrrhetinic Acid on the Protein Expression of PAI-1 and p22phox in Human Mononuclear Leukocytes
Authors: Calò Lorenzo A. , Zaghetto Francesca , Pagnin Elisa , Davis Paul A. , de Mozzi Paola , Sartorato Paola , Martire Giuseppe , Fiore Cristina , Armanini Decio 
Published: April 2004

Abstract
Aldosterone excess can produce heart and kidney fibrosis, which seem to be related to a direct effect of aldosterone at the level of specific receptors. We report a direct, mineralocorticoid-mediated effect on the protein expression of two markers of oxidative stress after incubation of mononuclear leukocytes with 1 × 10−8m aldosterone (p22phox/β-actin = 1.38 ± 0.05 and PAI-1/β-actin = 1.80 ± 0.05). The same effect was also found with 3 × 10−5m glycyrrhetinic acid, the principal constituent of licorice root (p22phox/β-actin = 1.37 ± 0.97 and PAI-1/β-actin = 1.80 ± 0.04). The effect of both aldosterone and glycyrrhetinic acid is blocked by incubation with added 1 × 10−6m of receptor-antagonist canrenone. Canrenone alone did not show any effect. PAI-1 related protein was also found using 4 × 10−9m aldosterone. Incubations with 1 × 10−9m for 3 hours as well as 1 × 10−8m aldosterone for 5, 10, and 20 minutes were ineffective for both proteins. These data support the previous finding of an involvement of mononuclear leukocytes in the pathogenesis of the oxidative stress induced by hyperaldosteronism. In addition, the results confirm our previous data on a direct effect of glycyrrhetinic acid at the level of mineralocorticoid receptors.
Improved Thermal Stability of Organically Modified Layered Silicates
Authors: Davis Rick D. , Gilman Jeffrey W. , Sutto Thomas E. , Callahan John H. , Trulove Paul C. , De Long Hugh C. 
Published: April 2004

AbstractBromide-containing impurities were found to decrease the thermal stability of quaternary alkyl ammonium-modified layered silicates. Improved purification procedures completely removed bromide and led to a 20°C to >100°C increase in organic modified layered silicate thermal stability. Using mass spectrometry and thermal and electrochemical analysis, N,N-dimethyl-N,N-dioctadecyl quaternary ammonium-modified montmorillonite and fluorinated synthetic mica were found to degrade primarily through elimination and nucleophilic attack by these anions. The nature of residual bromides was identified and quantified, and the efficiency of removing these anions was found to be solvent dependent; sequential extraction, first ethanol then tetrahydrofuran, gave the best results. This exhaustive extraction method represents a viable alternative to the use of expensive, more thermally stable oniumion treatments for layered silicates.
An In situ Time-Resolved XRD-PSD Investigation into Na-Montmorillonite Interlayer and Particle Rearrangement during Dehydration
Authors: Wilson James , Cuadros Javier , Cressey Gordon 
Published: April 2004

AbstractX-ray diffraction with a position-sensitive detector (XRD-PSD) was used to make a time-resolved study of the dynamics of deposition and dehydration of Na-montmorillonite crystallites on flat substrates from deionized water suspensions. The static PSD geometry and simultaneous counting procedure allowed the acquisition of high-resolution data on the dynamics of interlayer and interparticle arrangements during dehydration. Three experimental datasets of Na-smectite dehydration are presented, each one representing different initial sample states (suspension, slurry and re-wetted thin film). The computer program NEWMOD was used to simulate one of the three datasets (dehydration of a smectite suspension) and thus obtain the apparent changes in relative proportions of different 00l values as smectite crystallites formed and dehydrated. Two types of diffracting domains formed: water-dispersed ‘packets’ of 1–2 smectite layers gaining long-range order in the c axis direction as water was lost to evaporation, and smectite layers deposited as hydrated crystallites with variable interlayer water contents. The experimental patterns show the rapid step-wise transition of Na-montmorillonite layers from d values of ∼55 to 18.5, 15.4 and 12.5 Å, with variations that depended upon how the hydrated smectite sample was prepared. The simulations show that there was a wide range of d values whose frequency distribution changed as dehydration proceeded and that transient d values occurred between the peaks observed experimentally. The data obtained in this study illustrate that XRD-PSD instruments have great potential in providing detailed data on the rapid kinetics of interlayer reorganization.
Permeability of an Organo-Modified Bentonite to Ethanol-Water Solutions
Authors: Gates Will P. , Nefiodovas Andrew , Peter Paul 
Published: April 2004

AbstractPermeability is often the limiting factor in clay-based barrier systems designed to attenuate miscible or immiscible contaminant transport. One critical aspect of barrier design is prediction of the effects of permeant conditions on physicochemical properties (e.g swelling) of the clay component and thus, ultimately, the permeability of the barrier. To this end, the permeability of an organically modified bentonite to ethanol-water solutions was determined to approximate the effects of organo sorption-induced swelling. The bentonite was modified with a substituted alkylammonium cation: benzyloctadecyl-dimethylammonium (BODMA). Powder X-ray diffraction (XRD) measurements were used to measure interlayer expansion and to estimate aggregate particle densities at any given ethanol concentration. Permeability measurements were conducted on samples under confining overburden stresses of 43 kPa (∼2.5 m of saturated soil) using a hydraulic gradient of ∼300. Sample thickness was continuously monitored during measurements of volumetric flow so that sample strain, void ratio and porosity could be calculated from changes in sample pore volumes. For calculations of porosity and void ratio, the swelling solid volume, determined from XRD, was assumed to include the sorbed layer (crystalline water/ethanol), the thickness of which is not normally considered in engineering applications. Exposure of the BODMA bentonite to increasing ethanol concentrations increased the swell volume of the clay. Measured coefficients of permeability for the BODMA bentonite decreased from ∼1 × 10−7m s−1 for pure water to ∼8 × 10−10m s−1 for pure ethanol. Exposure of the organo clay to ethanol-water solutions containing 0.2 M NaCl increased the effect of ethanol on clay swelling and permeability. Probable consequences of the effects of sorption-induced swelling on permeability and the performance of organo clay-based permeable reactive barriers are discussed.
Ultramafic-Rock-Hosted Vein Sepiolite Occurrences in the Ankara Ophiolitic Mélange, Central Anatolia, Turkey
Authors: Yalçin Hüseyin , Bozkaya Ömer 
Published: April 2004

AbstractA 2 m thick brecciated zone containing magnesian minerals is present at the contact of tectonites and cumulates. Tectonites below this zone comprise serpentinized orthopyroxenite and serpentinite. An alteration zone with vein-type bedding comprises four different levels; from bottom to top they are: (1) green-brown serpentinite with dolomite (0.9 m), (2) light greenish-white dolomite with serpentine (0.5 m), (3) white dolomite with sepiolite (0.4 m), and (4) greenish-white dolomite with smectite-chlorite (0.2 m). The first level has a mineral association of serpentine + dolomite ± calcite ± aragonite, the second level consists of dolomite + serpentine ± calcite or dolomite + magnesite + serpentine, the third level comprises dolomite + sepiolite, and the fourth level is made up of dolomite + chlorite + smectite + serpentine. Dolomite, the main mineral of the alteration zone, occurs as coarse crystals (microsparitic-sparitic) in fractures and as small crystals (microsparitic-micritic) in the matrix, which includes serpentine and gabbro relics. Sepiolite developed at the edges and surfaces of dolomite and as fibrous forms in voids. Cumulate rocks above this zone comprise uralitic gabbros. The occurrences of magnesian minerals developed in three stages: the first stage was the serpentinization of olivine; the second stage was the dissolution of serpentine by groundwater and/or meteoric water containing carbon dioxide; and the last stage was the synthesis of neoformed minerals.
Synthesis of Birnessite from the Oxidation of Mn2+ by O2 in Alkali Medium: Effects of Synthesis Conditions
Authors: Feng Xiong Han , Liu Fan , Tan Wen Feng , Liu Xiang Wen 
Published: April 2004

AbstractAn O2 oxidation and freeze-dry procedure has been used to synthesize birnessite through the oxidation of Mn2+ in alkali media. The effects of O2 flow rate, the fluxion velocity of reaction suspension, the reaction temperature, pretreatment the reaction solutions with N2, and the hydration conditions on the purity of birnessite, the crystallinity, the ion-exchange properties, and the phase transformation of intermediate phases were examined. Buserite with a 1 nm basal spacing, produced after the oxidation, is transformed to 0.7 nm Na birnessite by complete freeze drying. Increasing the fluxion velocity of the reaction suspension and the O2 flow rate facilitated oxidation of Mn(OH)2. Prephase I (a phase related to hausmannite, γ-Mn3O4 (Luo and Suib, 1997; Luo et al., 1998), and feitknechtite (β-MnOOH) were formed as intermediates during the synthesis. Mechanical stirring was used to change the fluxion velocity of the reactive suspension. When the speed of stirring and the O2 flow rate were raised to 250 rpm and 3.0 L/min, respectively, or 450 rpm and 2.0 L/min, respectively, birnessite was the only phase in the final product. Irrespective of temperature in other reactions, pure birnessite was synthesized as long as the temperature during the initial mixing of the reaction solutions was maintained below 10°C. Increasing the reaction temperature led to a larger crystal size, better crystallinity and lower surface area. The pretreatment of solutions with N2 or O2 had little effect on the synthesis; synthesized birnessites had the same purity (100%) as, and similar crystallinity to, that of the no-pretreatment control. Dehydration of the buserite by freeze drying and heating at 60°C did not affect the production of birnessite; however, the latter caused partial loss of ion-exchange capacity with Mg2+. The pathways of the birnessite formation in this study might be:
(1)Mn(OH)2 (amorphous) → feitknechtite → buserite → birnessite, and(2)Mn(OH)2 (amorphous) → prephase I → feitknechtite → buserite → birnessiteMn(OH)2 existed in an X-ray amorphous state, not in the form of ‘pyrochroite’, during the synthesis.The adopted conditions for synthesis of pure birnessite were NaOH to Mn molar ratio of 13.7, O2 flow rate of 2 L/min and oxidation for 5 h during vigorous stirring at 450 rpm at room temperature. The birnessite synthesized had a hexagonal platy morphology with good crystallinity, an average composition of Na0.25MnO2.07.0.66H2O, and a surface area of 38 m2/g.