bluuebunny/crossref_metadata_2025 huggingface dataset:
Heme Oxygenase-1 Gene Expression Modulates Angiotensin II–Induced Increase in Blood Pressure
Authors: Yang Liming , Quan Shuo , Nasjletti Alberto , Laniado-Schwartzman Michal , Abraham Nader G.
Published: April 2004

The heme-heme oxygenase (HO) system has been implicated in the regulation of vascular reactivity and blood pressure. This study examines the notion that overexpression of HO decreases pressor responsiveness to angiotensin II (Ang II). Five-day-old Sprague-Dawley rats received an intraleft ventricular injection of ≈5×10
9
cfu/mL of retroviruses containing human HO-1 sense (LSN-HHO-1), rat HO-1 antisense (LSN-RHO-1-AS), or control retrovirus (LXSN). Three months later, rats were instrumented with femoral arterial and venous catheters for mean arterial pressure (MAP) determination and Ang II administration, respectively. Rats injected with LSN-HHO-1, but not with LXSN, expressed human HO-1 mRNA and protein in several tissues. BP increased with administration of Ang II in rats expressing and not expressing human HO-1. However, the Ang II-induced pressor response (mm Hg) in LSN-HHO-1 rats (16±3, 27±3, and 38±3 at 0.5, 2, and 10 ng) was surpassed (
P
<0.05) in LXSN rats (23±1, 37±2, and 52±2 at 0.5, 2, and 10 ng). Importantly, treating LSN-HHO-1 rats with the HO inhibitor tin mesoporphyrin (SnMP) enhanced (
P
<0.05) the Ang II-induced pressor response to a level not different from that observed in LXSN rats. Rats injected with LSN-RHO-1-AS showed a decrease in renal HO-1 protein expression and HO activity relative to control LXSN rats. Administration of Ang II (0.1 to 2 ng) caused small (4 to 5 mm Hg) but significant increases in MAP in rats injected with LSN-RHO-1-AS (
P
<0.05) compared with rats injected with LXSN. These data demonstrate that overexpression of HO-1 brings about a reduction in pressor responsiveness to Ang II, which is most likely due to increased generation of an HO-1 product, presumably CO, with the ability to inhibit vascular reactivity to constrictor stimuli.
Phosphoinositide-Dependent Kinase 1 and p21-Activated Protein Kinase Mediate Reactive Oxygen Species–Dependent Regulation of Platelet-Derived Growth Factor–Induced Smooth Muscle Cell Migration
Authors: Weber David S. , Taniyama Yoshihiro , Rocic Petra , Seshiah Puvi N. , Dechert Melissa A. , Gerthoffer William T. , Griendling Kathy K.
Published: April 2004

Smooth muscle cell migration in response to platelet-derived growth factor (PDGF) is a key event in several vascular pathologies, including atherosclerosis and restenosis. PDGF increases intracellular levels of reactive oxygen species (ROS) in vascular smooth muscle cells (VSMCs), but the ROS sensitivity of migration and of the signaling pathways leading to migration are largely unknown. In VSMCs, PDGF dose-dependently increased migration compared with nonstimulated cells, with a maximum increase at 10 ng/mL. Pretreatment with the antioxidant
N
-acetyl-cysteine, the flavin-containing enzyme inhibitor diphenylene iodonium, or the glutathione peroxidase mimetic ebselen significantly attenuated migration (PDGF alone, 5.0±1.1-fold; NAC, 1.8±0.2-fold; diphenylene iodonium, 1.4±0.3-fold migration; and ebselen, 2.0±0.5-fold migration), as did overexpression of catalase. Pretreatment of VSMCs with the Src inhibitor PP1 or dominant-negative Rac adenovirus significantly inhibited migration, but only Src activation was attenuated by ROS inhibitors. Phosphorylation of the Src- and Rac-effector p21-activated protein kinase (PAK) 1 on Thr423 (the phosphoinositide-dependent kinase-1 [PDK1] site) was attenuated by ROS inhibition, and infection of VSMCs with dominant-negative PAK1 adenovirus attenuated migration. Moreover, kinase-inactive K111N-PDK1 inhibited PAK1 phosphorylation on Thr423, and both K111N-PDK1 and Y9F-PDK1 significantly inhibited VSMC migration. PDK1 tyrosine phosphorylation was also ROS dependent. These data indicate that PDGF-induced VSMC migration is ROS dependent and identify the Src/PDK1/PAK1 signaling pathway as an important ROS-sensitive mediator of migration. Such information is critical to understanding the role of ROS in vascular diseases in which migration of VSMCs is an important component.
Critical Role of Monocyte Chemoattractant Protein-1 Receptor CCR2 on Monocytes in Hypertension-Induced Vascular Inflammation and Remodeling
Authors: Ishibashi Minako , Hiasa Ken-ichi , Zhao Qingwei , Inoue Shujiro , Ohtani Kisho , Kitamoto Shiro , Tsuchihashi Miyuki , Sugaya Takeshi , Charo Israel F. , Kura Shinobu , Tsuzuki Teruhisa , Ishibashi Tatsuro , Takeshita Akira , Egashira Kensuke
Published: April 2004

Activated monocytes are present in the arterial walls of hypertensive patients and animals. Monocyte chemoattractant protein-1 (MCP-1), which controls monocyte function through its receptor (CCR2), is implicated in hypertensive inflammatory changes in the arterial wall. The role of CCR2 expression on monocytes in hypertension-induced vascular remodeling, however, has not been addressed. We hypothesized that CCR2 on monocytes is critical in hypertension-induced vascular inflammation and remodeling. Hypertension was induced by infusion of angiotensin II (Ang II) into wild-type mice, CCR2-deficient (CCR2
−/−
) mice, and bone marrow-transferred mice with a leukocyte-selective CCR2 deficiency (BMT-CCR2
−/−
). In wild-type mice, Ang II increased CCR2 intensity in circulating monocytes, which was prevented by an Ang II type-1 (AT
1
) receptor blocker or blunted in AT
1
receptor-deficient mice. Enhanced CCR2 intensity on monocytes was observed in hypertensive patients and rats, and was reduced by treatment with the Ang II receptor blocker, supporting the clinical relevance of the observation in mice. In CCR2
−/−
and BMT-CCR2
−/−
mice, Ang II-induced vascular inflammation and vascular remodeling (aortic wall thickening and fibrosis) were blunted as compared with control mice. In contrast, Ang II-induced left ventricular hypertrophy developed in CCR2
−/−
and BMT-CCR2
−/−
mice. The present study suggests that CCR2 expression in monocytes has a critical role in vascular inflammation and remodeling in Ang II-induced hypertension, and possibly in other forms of hypertension.
Vertebral Artery Occlusion in Duplex Color-Coded Ultrasonography
Authors: Saito Kozue , Kimura Kazumi , Nagatsuka Kazuyuki , Nagano Keiko , Minematsu Kazuo , Ueno Satoshi , Naritomi Hiroaki
Published: April 2004

Background and Purpose—

To establish the diagnostic criteria for the site of occlusion in the vertebral arteries (VAs) using duplex color-coded ultrasonography.

Methods—

In 128 consecutive patients who underwent conventional cerebral angiography, we prospectively measured the diameter, mean flow velocity (MV), peak systolic flow velocity, and end-diastolic flow velocity of both VAs. The diameter-ratio (diameter of contralateral VA divided by that of target VA) and MV-ratio (MV of contralateral VA divided by that of target VA) were determined. Based on the angiographic findings, we classified the VAs into 4 types (5 groups) as follows: (1) the origin of VA occlusion (Origin group: n=9); (2) VA occlusion before branching into the posterior inferior cerebellar artery (PICA) (Before group: n=10); (3A) symptomatic VA occlusion after branching into the PICA (After group: n=12); (3B) asymptomatic or hypoplastic occlusive VA after branching into the PICA (PICA end group: n=15); and (4) no significant occlusive lesions in the VA (Control group: n=194).

Results—

No flow signals in the VAs apparently indicated the Origin group. Preserved peak systolic flow velocity but end-diastolic flow velocity of zero cm/s indicated the Before group. MV <18 cm/s and MV-ratio ≥1.4 indicated the PICA end group or After group. Furthermore, these groups could be distinguished as follows: a diameter-ratio <1.4 indicated the After group. A diameter-ratio ≥1.4 indicated the PICA end group. Either MV ≥18 cm/s or MV <18 cm/s in combination with MV-ratio <1.4 indicated the Control group.

Conclusion—

Duplex color-coded ultrasonography can accurately diagnose the site of VA occlusion.
Spike-Timing-Dependent Plasticity: The Relationship to Rate-Based Learning for Models with Weight Dynamics Determined by a Stable Fixed Point
Authors: Burkitt Anthony N. , Meffin Hamish , Grayden David. B.
Published: April 2004

Experimental evidence indicates that synaptic modification depends on the timing relationship between the presynaptic inputs and the output spikes that they generate. In this letter, results are presented for models of spike-timing-dependent plasticity (STDP) whose weight dynamics is determined by a stable fixed point. Four classes of STDP are identified on the basis of the time extent of their input-output interactions. The effect on the potentiation of synapses with different rates of input is investigated to elucidate the relationship of STDP with classical studies of long-term potentiation and depression and rate-based Hebbian learning. The selective potentiation of higher-rate synaptic inputs is found only for models where the time extent of the input-output interactions is input restricted (i.e., restricted to time domains delimited by adjacent synaptic inputs) and that have a time-asymmetric learning window with a longer time constant for depression than for potentiation. The analysis provides an account of learning dynamics determined by an input-selective stable fixed point. The effect of suppressive interspike interactions on STDP is also analyzed and shown to modify the synaptic dynamics.
Odor-Driven Attractor Dynamics in the Antennal Lobe Allow for Simple and Rapid Olfactory Pattern Classification
Authors: Galán Roberto Fdez. , Sachse Silke , Galizia C. Giovanni , Herz Andreas V. M.
Published: April 2004

The antennal lobe plays a central role for odor processing in insects, as demonstrated by electrophysiological and imaging experiments. Here we analyze the detailed temporal evolution of glomerular activity patterns in the antennal lobe of honeybees. We represent these spatiotemporal patterns as trajectories in a multidimensional space, where each dimension accounts for the activity of one glomerulus. Our data show that the trajectories reach odor-specific steady states (attractors) that correspond to stable activity patterns at about 1 second after stimulus onset. As revealed by a detailed mathematical investigation, the trajectories are characterized by different phases: response onset, steady-state plateau, response offset, and periods of spontaneous activity. An analysis based on support-vector machines quantifies the odor specificity of the attractors and the optimal time needed for odor discrimination. The results support the hypothesis of a spatial olfactory code in the antennal lobe and suggest a perceptron-like readout mechanism that is biologically implemented in a downstream network, such as the mushroom body.
Legal Aspects of Leasing: A Critical Review of Egyptian Law No. 95
Authors:   Mohamedien
Published: April 2004

No Abstract
Arab State Contract Disputes: Lessons from the Past
Authors:   Al-Jumah
Published: April 2004

No Abstract
New Amendments to the UAE Trademark Law Proposed
Authors:   Ashour
Published: April 2004

No Abstract
Legal Insight on the Dubai Electronic Transactions and Commerce Law No. 2 of 2002
Authors:   Qudah
Published: April 2004

No Abstract
Dissolution of Contract in Islamic Law
Authors: Islam
Published: April 2004

No Abstract
Protection of Trademarks in the Kingdom of Saudi Arabia
Authors: Garoub
Published: April 2004

No Abstract
Introduction: Cases in Islamic Finance
Authors: Al-Harran
Published: April 2004

No Abstract
The Experience of the Sudanese Islamic Bank in Partnership (Musharakah) Financing as a Tool for Rural Development Among Small Farmers in Sudan
Authors: Osman
Published: April 2004

No Abstract
New Strategic Alliances Between Islamic Financial Institutions, International University Students and Entrepreneurs to Implement Musharakah Financing to Meet the Challenges of the 21st Century
Authors: Al-Harran
Published: April 2004

No Abstract
THEOLOGY AND RELIGIOUS STUDIES IN THE POSTCOMMUNIST UKRAINE: History, Modern Status, Perspectives
Authors: Filipovych Lyudmyla , Kolodny Anatoly
Published: April 2004

Post-Soviet Ukrainian society has gone through drastic changes that have to be considered both at a secular and a theological level; the same can be said of Ukrainian society's attitude toward religion. The secular analysis of religion, including its individual and social dimensions, is now taking place within the framework of religious studies, the human sciences approach to religion being somewhat new in Ukraine. On the other hand, the theological interpretation of traditional and nontraditional religion is undergoing a reawakening. The causes for the undeveloped status of religious studies and theology have to do with the absence of Ukrainian statehood and Ukrainian churches, due to the domination of foreign and communist regimes. This domination led to the prohibition of religion as well as of its study; in present-day Ukraine, however, theology and religious studies appear as specific forms of knowledge about religion, and as subjects taught at schools and universities.
Individualized risks of first adverse events in patients with Fanconi anemia
Authors: Rosenberg Philip S. , Huang Yi , Alter Blanche P.
Published: April 2004

Fanconi anemia (FA) is an autosomal recessive condition associated with bone marrow failure (BMF) leading to death or hematopoietic stem cell transplantation, acute myeloid leukemia (AML), and solid tumors (STs). It is unclear which patients are most likely to develop each outcome. From a cohort of 144 North American patients with FA, we calculated individualized risks of each outcome, given the presence or absence of readily diagnosed congenital abnormalities that occur frequently in FA. Abnormal radii and a 5-item congenital abnormality score were significant risk factors for BMF. The cumulative incidence of BMF by age 10 years varied from 18% in the lowest BMF risk group to 83% in the highest. Because of competing risks, patients in the lowest BMF risk group were most likely to live long enough to develop AML or ST, and, conversely, patients in the highest BMF risk group were least likely to live long enough to develop AML or ST. By age 40, the cumulative incidence of ST ranged from 0.6% to 29% in the highest and lowest BMF risk groups, respectively. Abnormal radii are the strongest predictor of early BMF in FA; a congenital abnormality score separates patients with normal radii into distinct prognostic groups. (Blood. 2004;104:350-355)
Germ line tumor-associated immunoglobulin VH region peptides provoke a tumor-specific immune response without altering the response potential of normal B cells
Authors: Lou Qiang , Kelleher Raymond J. , Sette Alessandro , Loyall Jenni , Southwood Scott , Bankert Richard B. , Bernstein Steven H.
Published: April 2004

Previous studies have suggested that murine T cells are tolerant to epitopes derived from germ line variable regions of immunoglobulin (Ig) heavy (VH) or light chains. This has lead to the prediction that germ line VH-region epitopes found in neoplastic B cells cannot be used to provoke an antitumor immune response. To test these assumptions and address the question of how such a vaccine may alter the normal B-cell response, an antibody-forming B-cell hybridoma (1H6) expressing a conserved germ line VH gene with specificity for dextran was generated and used as a tumor model. Using algorithms for predicting major histocompatibility complex (MHC) binding, potential MHC class I and II binding peptides were identified within the 1H6 VH region, synthesized, and tested for MHC binding and immunogenicity. We show that germ line VH peptides, when presented by dendritic cells, are immunogenic in vitro and provoke a tumor-specific protective immune response in vivo. We conclude that (1) it is possible to induce a T-cell response to germ line VH peptides; (2) such peptides can be used to generate a B-cell tumor-specific vaccine; and (3) a vaccine targeting VH peptides expressed by the dominant dextran-specific B-cell clonotype had no effect upon the magnitude of the normal B-cell response to dextran.
Post-transcriptional regulation of proinflammatory proteins
Authors: Anderson Paul , Phillips Kristine , Stoecklin Georg , Kedersha Nancy
Published: April 2004

Post-transcriptional mechanisms play a critical role in regulating the expression of numerous proteins that promote inflammatory arthritis. The mRNAs encoding a subset of these proteins possess adenine/uridine-rich elements (AREs) in their 3′-untranslated regions that profoundly influence the rate at which mRNA is degraded and translated into protein. Tristetraprolin (TTP) and T cell intracellular antigen-1 (TIA-1) are ARE-binding proteins that dampen the expression of this class of proteins by promoting mRNA degradation and protein translation, respectively. We have discovered that TIA-1 and TTP function as arthritis-suppressor genes: TIA-1−/− mice develop mild arthritis, TTP−/− mice develop severe arthritis, and TIA-1−/−TTP−/− mice develop very severe arthritis. Paradoxically, lipopolysaccharide (LPS)-activated macrophages derived from TIA-1−/−TTP−/− macrophages produce less tumor necrosis factor α (TNF-α) than TIA-1−/− or TTP−/− macrophages. The bone marrows of these mice exhibit increased cellularity, reflecting the presence of mature neutrophils that secrete TNF-α in response to LPS stimulation. We hypothesize that TIA-1−/−TTP−/− neutrophils are a source of arthritigenic TNF-α, which promotes severe erosive arthritis in these mice.
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

Vigorous 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.
Size and strength: do we need both to measure vocabulary knowledge?
Authors: Laufer Batia , Elder Cathie , Hill Kathryn , Congdon Peter
Published: April 2004

This article describes the development and validation of a test of vocabulary size and strength. The rst part of the article sets out the theoretical rationale for the test, and describes how the size and strength constructs have been conceptualized and operationalized. The second part of the article focusses on the process of test validation, which involved the testing of the hypotheses implicit in the test design, using both unidimensional and multifaceted Rasch analyses. Possible applications for the test include determining the status of a learner’s vocabulary development as well as screening and placement. A model for administering the test in computer adaptive mode is also proposed. The study has implications both for the design and delivery of this test as well as for theories of vocabulary acquisition.
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.
The performance of native speakers of English and ESL speakers on the computer-based TOEFL and GRE General Test
Authors: Stricker Lawrence J.
Published: April 2004

The purpose of this study was to replicate previous research on the construct validity of the paper-based version of the TOEFL and extend it to the computer-based TOEFL. Two samples of Graduate Record Examination (GRE) General Test-takers were used: native speakers of English specially recruited to take the computer-based TOEFL, and ESL test-takers who routinely took the computer-based TOEFL recently. Native speakers performed well on the TOEFL, relative to ESL test-takers and to the maximum possible scores on the test, and varied less in their test performance than did ESL test-takers. TOEFL scores were moderately or highly correlated with the computer-based GRE General Test scores for both groups of test-takers. Regressions of the GRE General Test Verbal scores on the TOEFL scores for ESL test-takers were nonlinear, and the regressions of the other GRE General Test scores were linear. And trends in the variances of the GRE General Test Verbal scores associated with TOEFL scores were also nonlinear, and the trends were either unsystematic or negatively linear for the other GRE General Test scores. All of the ndings are consistent with previous results with the paper-based TOEFL, support the construct validity of the computer-based TOEFL, and underscore its usefulness in interpreting the performances of ESL test-takers on admissions tests for English-speaking test-takers.
Dry deposition (downward, upward) concentration study of particulates and water-soluble ionic species during daytime, night-time period at the traffic sampling site of Sha-Lu, Taiwan
Authors: Wu Yuh-Shen , Fang Guor-Cheng , Rau Jui-Yeh , Huang Shih-Han
Published: April 2004

Ambient suspended particulate (dry deposition, TSP) was collected in the traffic sites Sha-Lu, central Taiwan. In addition, the related water-soluble ionic species (Cl1/4, NO31/4, SO421/4, Na+, NH4+, K+, Mg2+and Ca2+) were analysed and wind speed, wind direction and temperature were also measured in this study. The downward dry deposition fluxes (averaged 54.07 mg/m2-sec) were about twice that of upward dry deposition fluxes (averaged 26.48 mg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 mg/m2-sec) were also about twice that of upward dry deposition fluxes (averaged 12.11 mg/m2-sec) in the night-time period. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 mg/m3) were higher than in the night-time period (averaged 560.7 mg/m3). The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 mg/m3) were higher than in night-time period (averaged 560.7 mg/m3). As for water-soluble ionic species, the average dry deposition order and velocity for downward ionic species were Cl1/4 Í-Ca2+Í-NO31/4 Í-K+(2.09 cm/sec Í-1.46 cm/sec Í-1.46 cm/sec Í-1.07 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for downward ionic species were NO31/4 Í / Cl1/4 Í / K+Í / Ca2+(2.92 cm/sec Í / 2.74 cm/sec Í / 0.96 cm/sec Í / 0.93 cm/sec) anions during the night-time period. The average dry deposition order and velocity for upward ionic species were Cl1/4 Í / Ca2+Í / K+Í / Mg2+(4.69 cm/sec Í / 0.62 cm/sec Í / 0.59 cm/sec Í / 0.55 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for upward ionic species were Cl1/4 Í-Ca2+Í-Mg2+Í-K+(1.65 cm/sec Í-0.43 cm/sec Í / 0.37 cm/sec Í / 0.33 cm/sec) anions during the night-time period. The results also indicated that the sodium and chloride concentrations in total suspended particulate were highly positively related, indicating that the sea-salt aerosols were the major contributors for these species at this sampling site of central Taiwan.
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

Apolipoprotein 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

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

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

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 < 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

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 < 0.001) and an inverse function of serum 25(OH)D (P < 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

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.
Competition in Japan
Authors: Porter Michael E , Sakakibara Mariko
Published: April 2004

This article examines competition in Japan and its link to postwar economic prosperity. While Japan's industrial structure and competition policy seem to indicate that competition in Japan has been less intense, the empirical evidence does not support this conclusion. The sectors in which competition was restricted prove to be those where Japan was not internationally successful. In the internationally successful sectors, internal competition in Japan was invariably fierce. While the level of competition in Japan is currently rising, economic recovery is still hindered by distortions in the competition in many industries.
Static Flexural Behaviour of Externally Post-Tensioned Steel-Concrete Composite Beams
Authors: Uy Brian , Craine Stewart
Published: April 2004

Composite steel-concrete beams are used widely in bridge and building construction as the main structural elements in flexure. Bridges, throughout the world have a design life and this may be reduced if traffic flows are increased or environmental degradation occurs. Similarly, building beams may become compromised for serviceability or strength when loads on floor systems are increased. These changes may reduce the design life and strength of such members and thus replacement or retrofitting may need to be considered. One method of retrofitting (stiffening and strengthening) a composite steel-concrete beam is to externally post-tension the beam. The application of external post-tensioning also has the effect of increasing the fatigue life of such members. This paper provides a set of detailed experiments on both a conventional and prestressed composite steel-concrete beam. A numerical model is then developed for the load-deflection response and this is calibrated with the test data. An extensive parametric study is then conducted to consider the influence of various parameters on the behaviour of these beams. Finally a rigid plastic analysis procedure is presented and calibrated with the test results with good effect. This procedure is considered to be amenable for design in assessing the flexural strength.
Damped Spectral Element Method for Global Dynamic Analysis of Chimneys
Authors: Horr A. M. , Safi M. , Asadpour N.
Published: April 2004

Conventional finite element method has been used successfully in linear and nonlinear analyses in tall chimney structures. The method can be performed by subdividing the large structure with small uniform elements having approximate shape functions. Although this replaces a single complicated structural system with the number of simple uniform elements, in cases of tall concrete chimney structures with cracking and crushing behavior in concrete material and yielding in the reinforcement, the computer time and memory can be large. Hence, it is desirable to search for a procedure requiring lesser number of elements and also less computer time and effort to model a structure. In this respect, attention is paid to the advanced complex damped spectral element method, which benefits from the more accurate and also mathematically complicated shape functions. The use of advanced spectral element method can help engineers to design a complex structure, like a tall concrete tower, with a lower cost and weight. Using a computer program, the proposed formulation has been used to derive the non-linear dynamic response of tall concrete chimney.
Post Local Buckling of Skew and Trapezoidal Plates
Authors: Azhari M. , Shahidi A. R. , Saadatpour M. M.
Published: April 2004

A numerical procedure is developed for the post-buckling analysis of skew and trapezoidal plates. The procedure uses virtual work method in conjunction with the natural coordinates. The post-buckling equilibrium path is controlled by the Hookean strains and the total potential energy is formulated as a function of the compressive strain rather than stresses. The method is programmed, and several numerical examples are presented to illustrate the scope and ability of the procedure. Initial local buckling results obtained for skew plates are compared with known solutions in the literature. Post-buckling behavior of skew and trapezoidal plates is studied for different geometries. The non-dimensional loads carried in the plate and dimensionless lateral displacements of skew and trapezoidal plate in the post buckling region are given in several tables.
The Prediction of Damage to Masonry Houses Caused by Foundation Movements
Authors: Zhuge Y. , Jin F. , Hunt S.
Published: April 2004

Cracking failure in masonry houses founded on expansive soils has been widely reported throughout Australia and other countries. The cost associated with such damage is significant. The current codes of practice only provide broad guidance on the design principles of masonry under ground movement, due to a lack of research in the area. In this paper a numerical model has been developed to study the behaviour of masonry walls under footing movements as a result of expansive soils. The model is based on Distinct Element Method (DEM) which has been applied successfully by the authors to model the masonry walls under simulated (static) in-plane earthquake forces. The model is capable of predicting the crack initiation, propagation and failure modes of masonry walls under various footing movements (doming or dishing curvatures). The numerical solutions obtained from the distinct element analysis are validated by comparing the results with those obtained from the existing experiments.
Seismic Response of Fire-Damaged Reinforced Concrete Buildings
Authors: Mo Y. L. , Hwang C. , Wang Jun
Published: April 2004

The constitutive laws for concrete and steel under fire environments are cast into a computer model that is combined with the algorithm for seismic response analysis of reinforced concrete buildings. Using this algorithm, a computer program has been developed, and a reinforced concrete building is taken as an example to show the applicability. Finally the effects of fire locations, fire duration, ground acceleration and axial forces on such buildings are investigated.
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

Bromide-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

X-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

Permeability 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.