bluuebunny/crossref_metadata_2025 huggingface dataset:
Arterial Smooth Muscle Cell Heterogeneity
Authors: Hao Hiroyuki , Gabbiani Giulio , Bochaton-Piallat Marie-Luce
Published: August 2003

During atheromatous plaque formation or restenosis after angioplasty, smooth muscle cells (SMCs) migrate from the media toward the intima, where they proliferate and undergo phenotypic changes. The mechanisms that regulate these phenomena and, in particular, the phenotypic modulation of intimal SMCs have been the subject of numerous studies and much debate during recent years. One view is that any SMCs present in the media could undergo phenotypic modulation. Alternatively, the seminal observation of Benditt and Benditt that human atheromatous plaques have the features of a monoclonal or an oligoclonal lesion has led to the hypothesis that a predisposed, medial SMC subpopulation could play a crucial role in the production of intimal thickening. The presence of a distinct SMC population in the arterial wall implies that under normal conditions, SMCs are phenotypically heterogeneous. The concept of SMC heterogeneity is gaining wider acceptance, as shown by the increasing number of publications on this subject. In this review, we discuss the in vitro studies that demonstrate the presence of distinct SMC subpopulations in arteries of various species, including humans. Their specific features and their regulation will be highlighted. Finally, the relevance of an atheroma-prone phenotype to intimal thickening formation will be discussed.
The Receptor RAGE as a Progression Factor Amplifying Arachidonate-Dependent Inflammatory and Proteolytic Response in Human Atherosclerotic Plaques
Authors: Cipollone Francesco , Iezzi Annalisa , Fazia Maria , Zucchelli Mirco , Pini Barbara , Cuccurullo Chiara , De Cesare Domenico , De Blasis Giovanni , Muraro Raffaella , Bei Roberto , Chiarelli Francesco , Schmidt Ann Marie , Cuccurullo Franco , Mezzetti Andrea
Published: August 2003

Background—

RAGE (receptor for advanced glycation end products [AGEs]) plays a role in diabetic atherosclerosis. Recently, we have demonstrated enhanced expression of cyclooxygenase-2 and PGE synthase-1 (COX-2/mPGES-1) in human symptomatic plaques, and provided evidence that it is associated with metalloproteinase (MMP)-induced plaque rupture. However, the specific transmembrane signaling pathway(s) influencing plaque COX-2/mPGES-1 expression is unknown. The aim of this study was to characterize RAGE expression in human plaques and to correlate it with the inflammatory infiltration, COX-2/mPGES-1 and MMP expression, and with clinical evidence of diabetes.

Methods and Results—

Plaques obtained from 60 patients undergoing carotid endarterectomy were divided into diabetic and nondiabetic according to clinical evidence of type 2 diabetes. Plaques were subjected to analysis of RAGE, NF-κB, COX-2/mPGES-1, MMP-2 and MMP-9, lipid and oxidized LDL (oxLDL) content, and collagen content by immunohistochemistry and Western blot, whereas zymography was used to detect MMP activity. Immunohistochemistry was used to identify CD68+ macrophages, CD3+ T-lymphocytes, smooth muscle cells (SMCs), and HLA-DR+ inflammatory cells. Diabetic plaques had more (
P
<0.0001) macrophages, T-lymphocytes, and HLA-DR+ cells, more (
P
<0.0001) immunoreactivity for RAGE, activated NF-κB, COX-2/mPGES-1, and MMPs, increased (
P
<0.0001) gelatinolytic activity, reduced (
P
<0.0001) collagen content, and increased (
P
<0.0001) lipid and oxLDL content. Interestingly, RAGE, COX-2/mPGES-1, and MMP expression was linearly correlated with plasma level of HbA1c.

Conclusions—

In conclusion, this study demonstrates in humans that RAGE overexpression is associated with enhanced inflammatory reaction and COX-2/mPGES-1 expression in diabetic plaque macrophages, and this effect may contribute to plaque destabilization by inducing culprit metalloproteinase expression.
Hemodynamic Profile After the Norwood Procedure With Right Ventricle to Pulmonary Artery Conduit
Authors: Maher Kevin O. , Pizarro Christian , Gidding Samuel S. , Januszewska Katarzyna , Malec Edward , Norwood William I. , Murphy John D.
Published: August 2003

Background—

The balance of systemic, pulmonary, and coronary blood flow after the Norwood operation for hypoplastic left heart syndrome (HLHS) is critical to early survival. We hypothesized that a right ventricle to pulmonary artery conduit (instead of a systemic to pulmonary artery shunt) would result in hemodynamic changes consistent with a more stable balance of systemic, pulmonary, and coronary perfusion.

Methods and Results—

Hemodynamic data were obtained during cardiac catheterization before the hemi-Fontan procedure from 24 patients with HLHS; the first 10 had a Norwood operation with a systemic to pulmonary artery shunt, and the latter 14 had the Norwood operation with a right ventricle to pulmonary artery conduit. Significant differences were present, with the right ventricle to pulmonary artery conduit group having a higher aortic diastolic pressure (55 versus 42 mm Hg), a narrowed systemic pulse pressure (43 versus 64 mm Hg), a lower Qp:Qs (0.92 versus 1.42), a higher coronary perfusion pressure (46 versus 32 mm Hg), and a higher ratio of pulmonary artery diameter to descending aorta diameter (1.51 versus 1.37).

Conclusions—

We conclude that, in HLHS after the Norwood operation, the right ventricle to pulmonary artery conduit modification produces hemodynamic changes consistent with improved coronary perfusion and a more favorable distribution of systemic, pulmonary, and coronary blood flow.
Effects of Heart Rate Changes on Arterial Distensibility in Humans
Authors: Giannattasio Cristina , Vincenti Antonio , Failla Monica , Capra Anna , Cirò Antonio , De Ceglia Sergio , Gentile Gaetano , Brambilla Roberta , Mancia Giuseppe
Published: August 2003

In rats, an increase in heart rate by pacing is accompanied by progressive large-artery stiffening. Whether this is also the case in humans is unknown. We enrolled 20 patients who were chronically implanted with a pacemaker because of atrioventricular block or sick sinus syndrome. Arterial distensibility was measured by an echo-tracking device. In 10 patients, the evaluation was performed on the radial artery by using continuous finger blood pressure measurements, whereas in the remaining 10 patients, the common carotid artery was studied with a semiautomatic measure of brachial artery blood pressure. Diastolic diameter, systodiastolic diameter change, and distensibility were obtained at baseline (heart rate 63±2 beats/min) and after atrial and ventricular sequential pacing at a heart rate of 90 and 110 beats/min. At baseline, the diameter was 7.8±0.3 mm in the carotid artery and 2.4±0.1 mm in the radial artery; the respective systodiastolic diameter change values were 375.4±31.0 and 55.9±9.0 (μm) and the distensibility values were 1.4±0.1 and 0.7±0.1 (1/mm Hg 10
−3
). Blood pressure and diameter were not significantly modified by increasing heart rate, which markedly modified systodiastolic diameter change and distensibility. In the radial artery, distensibility was reduced by 47% (
P
<0.05) at a heart rate of 90 beats/min with no further reduction at 110 beats/min. In the carotid artery, distensibility was reduced by 20% at a heart rate of 90 beats/min (
P
<0.05) with a further reduction at 110 beats/min (45%,
P
<0.05). These data provide the first evidence in humans that acute increases in heart rate markedly affect arterial distensibility and that this occurs in both large- and middle-size muscle arteries within the range of “normal” heart rate values.
Coronary Angiography Is the Best Predictor of Events in Renal Transplant Candidates Compared With Noninvasive Testing
Authors: De Lima Jose Jayme G. , Sabbaga Emil , Vieira Marcelo Luis C. , de Paula Flavio J. , Ianhez Luis E. , Krieger Eduardo M. , Ramires Jose Antonio F.
Published: August 2003

Guidelines for the detection of coronary artery disease (CAD) and assess of risk in renal transplant candidates are based on the results of noninvasive testing, according to data originated in the nonuremic population. We evaluated prospectively the accuracy of 2 noninvasive tests and risk stratification in detecting CAD (≥70% obstruction) and assessing cardiac risk by using coronary angiography (CA). One hundred twenty-six renal transplant candidates who were classified as at moderate (≥50 years) or high (diabetes, extracardiac atherosclerosis, or clinical coronary artery disease) coronary risk underwent myocardial scintigraphy (SPECT), dobutamine stress echocardiography, and CA and were followed for 6 to 48 months. The prevalence of CAD was 42%. The sensitivities and negative predictive values for the 2 noninvasive tests and risk stratification were <75%. After 6 to 48 months, there were 18 cardiac events, 9 fatal. Risk stratification (
P
=0.007) and CA (
P
=0.0002) predicted the crude probability of surviving free of cardiac events. The probability of event-free survival at 6, 12, 24, 36, and 48 months were 98%, 98%, 94%, 94%, and 94% in patients with <70% stenosis on CA and 97%, 87%, 61%, 56%, and 54% in patients with ≥70% stenosis. Multivariate analysis showed that the sole predictor of cardiac events was critical coronary lesions (
P
=0.003). Coronary angiography may still be necessary for detecting CAD and determining cardiac risk in renal transplant candidates. The data suggest that current algorithms based on noninvasive testing in this population should be revised.
Changes in the Ca
2+
-Activated K
+
Channels of the Coronary Artery During Left Ventricular Hypertrophy
Authors: Kim Nari , Chung Joonyong , Kim Euiyong , Han Jin
Published: August 2003

It has been suggested that impairment of smooth muscle cell (SMC) function by alterations in the Ca
2+
-activated K
+
(K
Ca
) channels accounts for the reduction in coronary reserve during left ventricular hypertrophy (LVH). However, this hypothesis has not been fully investigated. The main goal of this study was to assess whether the properties of K
Ca
channels in coronary SMCs were altered during LVH. In patch-clamp experiments, the whole-cell currents of the K
Ca
channels were reduced during LVH. The unitary current amplitude and open probability for the K
Ca
channels were significantly reduced in LVH patches compared with control patches. The concentration-response curve of the K
Ca
channel to [Ca
2+
]
i
was shifted to the right. Inhibition of the K
Ca
channels by tetraethylammonium (TEA) was more pronounced in LVH cells than in control cells. Western blot analysis indicated no differences in K
Ca
channel expression between the control and LVH coronary SM membranes. In contraction experiments, the effect of high K
+
concentration on the resting tension of the LVH coronary artery was greater than on that of the control. The effect of TEA on the resting tension of the LVH coronary artery was reduced compared with the effect on the control. Our findings imply a novel mechanism for reduced coronary reserve during LVH.
Fiber-Tracking Method Reveals Sensorimotor Pathway Involvement in Stroke Patients
Authors: Yamada Kei , Mori Susumu , Nakamura Hisao , Ito Hirotoshi , Kizu Osamu , Shiga Kensuke , Yoshikawa Kenji , Makino Masahiro , Yuen Sachiko , Kubota Takao , Tanaka Osamu , Nishimura Tsunehiko
Published: August 2003

Background and Purpose—

We tested the feasibility of a new MRI technique that provides visualization of the sensorimotor tracts in vivo in a group of stroke victims.

Summary of Report—

Fourteen patients with small infarctions involving the white matter of the supratentorial brain were evaluated. Sensorimotor tracts on the lesional and contralesional sides were successfully depicted in all cases. The position of the sensorimotor tracts relative to the infarct was in good agreement with clinical symptoms. The overall sensitivity and specificity for sensorimotor tract involvement were 100% and 77%, respectively.

Conclusions—

Our proposed fiber-tracking method was shown to be a clinically feasible technique that correlates well with clinical symptoms.
Prospective Evaluation of Carotid Bruit as a Predictor of First Stroke in Type 2 Diabetes
Authors: Gillett Melissa , Davis Wendy A. , Jackson Denise , Bruce David G. , Davis Timothy M.E.
Published: August 2003

Background and Purpose—

We sought to examine prospectively the relationship between asymptomatic carotid bruit and stroke in type 2 diabetes.

Methods—

We studied 1181 (91.3%) of a community-based sample of 1294 patients with type 2 diabetes. These patients had no history of cerebrovascular disease at recruitment during 1993–1996 and were followed until the end of January 2002. Hospital morbidity and death register data relating to cerebrovascular events were also available. Cox proportional hazards models were used to determine whether carotid bruit status was an independent predictor of stroke and to identify other significant cerebrovascular risk factors.

Results—

One hundred thirty-four patients (11.3%) suffered a first stroke during 6.5±2.2 (mean±SD) years of follow-up. In the first 2 years after study entry, first stroke (n=45/1181; 3.8%) was strongly predicted by the presence of carotid bruit(s) after adjustment for known cardiovascular risk factors and other potentially confounding variables (hazard ratio, 6.7; 95% CI, 3.0 to 14.9;
P
<0.001). Between 2 years and census, first stroke (n=89/1083; 8.2%) was not associated with carotid bruit(s) (
P
=0.97). Age and diastolic blood pressure were other determinants of stroke in the first 2 years, while age, atrial fibrillation/flutter, and microalbuminuria were independent predictors of subsequent stroke.

Conclusions—

Type 2 diabetic patients found to have incidental carotid bruits have >6 times the risk of first stroke in the first 2 years than patients without a bruit and should receive intensified management of vascular risk factors. Carotid imaging with a view to surgical intervention in these patients remains controversial.
A role for Rab27b in NF-E2-dependent pathways of platelet formation
Authors: Tiwari Sanjay , Italiano Joseph E. , Barral Duarte C. , Mules Emilie H. , Novak Edward K. , Swank Richard T. , Seabra Miguel C. , Shivdasani Ramesh A.
Published: August 2003

Megakaryocytes release platelets by reorganizing the cytoplasm into proplatelet extensions. Fundamental to this process is the need to coordinate transport of products and organelles in the appropriate abundance to nascent platelets. The importance of the Rab family of small GTPases (guanosine 5′-triphosphatases) in platelet biogenesis is revealed in gunmetal (gm/gm) mice, which show deficient Rab isoprenylation and macrothrombocytopenia with few granules and abnormal megakaryocyte morphology. Although some Rab proteins are implicated in vesicle and organelle transport along microtubules or actin, the role of any Rab protein in platelet biogenesis is unknown. The limited number of Rab proteins with defective membrane association in gm/gm megakaryocytes prominently includes Rab27a and Rab27b. Normal expression of Rab27b is especially increased with terminal megakaryocyte differentiation and dependent on nuclear factor-erythroid 2 (NF-E2), a transcription factor required for thrombopoiesis. Chromatin immunoprecipitation demonstrates recruitment of NF-E2 to the putative Rab27B promoter. Inhibition of endogenous Rab27 function in primary megakaryocytes causes severe quantitative and qualitative defects in proplatelet formation that mimic findings in gm/gm cells. Rab27b localizes to alpha and dense granules in megakaryocytes. These results establish a role for Rab27 in platelet synthesis and suggest that Rab27b in particular may coordinate proplatelet formation with granule transport, possibly by recruiting specific effector pathways.
IL-10-inducible Bcl-3 negatively regulates LPS-induced TNF-α production in macrophages
Authors: Kuwata Hirotaka , Watanabe Yasuyuki , Miyoshi Hiroyuki , Yamamoto Masahiro , Kaisho Tsuneyasu , Takeda Kiyoshi , Akira Shizuo
Published: August 2003

Interleukin-10 (IL-10) plays an important role in prevention of chronic inflammation in vivo. However, the molecular mechanism by which IL-10 exerts its anti-inflammatory response is poorly understood. Here, we performed a microarray analysis and identified Bcl-3 as an IL-10-inducible gene in macrophages. Lentiviral vector-mediated expression of Bcl-3 inhibited lipopolysaccharide (LPS)-induced production of tumor necrosis factor α (TNF-α), but not IL-6, in macrophages. In Bcl-3-transduced and IL-10-pretreated macrophages, LPS-induced nuclear translocation of nuclear factor κB (NF-κB) p65 was not impaired. However, DNA binding by NF-κB p50/p65 was profoundly inhibited. Nuclear localization of Bcl-3 was associated with inhibition of LPS-induced TNF-α production. Overexpression of Bcl-3 suppressed activation of the TNF-α promoter, but not the IL-6 promoter. Bcl-3 interacted with NF-κB p50 and was recruited to the TNF-α promoter, but not the IL-6 promoter, indicating that Bcl-3 facilitates p50-mediated inhibition of TNF-α expression. Furthermore, Bcl-3-deficient macrophages showed defective IL-10-mediated suppression of LPS induction of TNF-α, but not IL-6. These findings suggest that IL-10-induced Bcl-3 is required for suppression of TNF-α production in macrophages. (Blood. 2003; 102:4123-4129)
Iron loading and erythrophagocytosis increase ferroportin 1 (FPN1) expression in J774 macrophages
Authors: Knutson Mitchell D. , Vafa Mohammad R. , Haile David J. , Wessling-Resnick Marianne
Published: August 2003

The expression of ferroportin1 (FPN1) in reticuloendothelial macrophages supports the hypothesis that this iron-export protein participates in iron recycling from senescent erythrocytes. To gain insight into FPN1's role in macrophage iron metabolism, we examined the effect of iron status and erythrophagocytosis on FPN1 expression in J774 macrophages. Northern analysis indicated that FPN1 mRNA levels decreased with iron depletion and increased on iron loading. The iron-induced induction of FPN1 mRNA was blocked by actinomycin D, suggesting that transcriptional control was responsible for this effect. After erythrophagocytosis, FPN1 mRNA levels were also up-regulated, increasing 8-fold after 4 hours and returning to basal levels by 16 hours. Western analysis indicated corresponding increases in FPN1 protein levels, with maximal induction after 10 hours. Iron chelation suppressed FPN1 mRNA and protein induction after erythrophagocytosis, suggesting that FPN1 induction results from erythrocyte-derived iron. Comparative Northern analyses of iron-related genes after erythrophagocytosis revealed a 16-fold increase in FPN1 levels after 3 hours, a 10-fold increase in heme oxygenase-1 (HO-1) after 3 hours, a 2-fold increase in natural resistance macrophage-associated protein 1 (Nramp1) levels after 6 hours, but no change in divalent metal ion transporter 1 (DMT1) levels. The rapid and strong induction of FPN1 expression after erythrophagocytosis suggests that FPN1 plays a role in iron recycling. (Blood. 2003;102:4191-4197)
Role of Ras signaling in erythroid differentiation of mouse fetal liver cells: functional analysis by a flow cytometry–based novel culture system
Authors: Zhang Jing , Socolovsky Merav , Gross Alec W. , Lodish Harvey F.
Published: August 2003

Ras signaling plays an important role in erythropoiesis. Its function has been extensively studied in erythroid and nonerythroid cell lines as well as in primary erythroblasts, but inconclusive results using conventional erythroid colony-forming unit (CFU-E) assays have been obtained concerning the role of Ras signaling in erythroid differentiation. Here we describe a novel culture system that supports terminal fetal liver erythroblast proliferation and differentiation and that closely recapitulates erythroid development in vivo. Erythroid differentiation is monitored step by step and quantitatively by a flow cytometry analysis; this analysis distinguishes CD71 and TER119 double-stained erythroblasts into different stages of differentiation. To study the role of Ras signaling in erythroid differentiation, different H-ras proteins were expressed in CFU-E progenitors and early erythroblasts with the use of a bicistronic retroviral system, and their effects on CFU-E colony formation and erythroid differentiation were analyzed. Only oncogenic H-ras, not dominant-negative H-ras, reduced CFU-E colony formation. Analysis of infected erythroblasts in our newly developed system showed that oncogenic H-ras blocks terminal erythroid differentiation, but not through promoting apoptosis of terminally differentiated erythroid cells. Rather, oncogenic H-ras promotes abnormal proliferation of CFU-E progenitors and early erythroblasts and supports their erythropoietin (Epo)–independent growth.
HTLV-1 Rex is required for viral spread and persistence in vivo but is dispensable for cellular immortalization in vitro
Authors: Ye Jianxin , Silverman Lee , Lairmore Michael D. , Green Patrick L.
Published: August 2003

Human T-cell leukemia virus type 1 (HTLV-1) is associated with leukemia/lymphoma and neurologic disorders. Although the viral transcriptional activator Tax is the critical viral oncoprotein, Rex, which regulates the expression of the viral structural and enzymatic genes, is essential for efficient viral replication. Herein, we investigate the contribution of Rex in HTLV-1 immortalization of primary T cells in vitro and viral survival in an infectious rabbit animal model. A Rex-deficient HTLV-1 (HTLVRex-) was constructed and characterized for viral gene expression, protein production, and immortalization capacity. Cells transiently transfected with the HTLVRex- proviral clone produced low detectable levels of p19 Gag. 729HTLVRex- stable transfectants produced functional Tax, but undetectable levels of Rex or p19 Gag. Coculture of irradiated 729HTLVRex- cells with peripheral blood mononuclear cells (PBMCs) resulted in sustained interleukin-2 (IL-2)-dependent growth of primary T lymphocytes. These cells carried the HTLVRex- genome and expressed tax/rex mRNA but produced no detectable Rex or p19 Gag. Rabbits inoculated with irradiated 729HTLVRex- cells or 729HTLVRex- cells transiently transfected with a Rex cDNA expression plasmid failed to become persistently infected or mount a detectable antibody response to the viral gene products. Together, our results provide the first direct evidence that Rex and its function to modulate viral gene expression and virion production is not required for in vitro immortalization by HTLV-1. However, Rex is critical for efficient infection of cells and persistence in vivo.
Coagulation, inflammation, and apoptosis: different roles for protein S and the protein S–C4b binding protein complex
Authors: Rezende Suely Meireles , Simmonds Rachel Elizabeth , Lane David Anthony
Published: August 2003

Protein S (PS) has an established role as an important cofactor to activated protein C (APC) in the degradation of coagulation cofactors Va and VIIIa. This anticoagulant role is evident from the consequences of its deficiency, when there is an increased risk of venous thromboembolism. In human plasma, PS circulates approximately 40% as free PS (FPS) and 60% in complex with C4b-binding protein (C4BP). Formation of this complex results in loss of PS cofactor function, and C4BP can then modulate the anticoagulant activity of APC. It had long been predicted that the complex could act as a bridge between coagulation and inflammation due to the involvement of C4BP in regulating complement activation. This prediction was recently supported by the demonstration of binding of the PS-C4BP complex to apoptotic cells. This review aims to summarize recent findings on the structure and functions of PS, the basis and importance of its deficiency, its interaction with C4BP, and the possible physiologic and pathologic importance of the PS-C4BP interaction.
CD25 expression on donor CD4+ or CD8+ T cells is associated with an increased risk for graft-versus-host disease after HLA-identical stem cell transplantation in humans
Authors: Stanzani Marta , Martins Sergio L. R. , Saliba Rima M. , John Lisa S. St. , Bryan Susan , Couriel Daniel , McMannis John , Champlin Richard E. , Molldrem Jeffrey J. , Komanduri Krishna V.
Published: August 2003

Graft-versus-host disease (GVHD) occurs in an unpredictable fashion after 30% to 50% of matched-related transplantations. The presence of increased frequencies of CD4+CD25+ regulatory T cells in donor grafts has been shown to ameliorate GVHD after allogeneic transplantation in murine models. To determine whether a similar relationship exists in humans, we quantitated the coexpression of CD25 on CD4+ and CD8+ T cells within 60 donor grafts infused into matched siblings and examined GVHD incidence in the respective recipients. Recipients in whom GVHD developed received donor grafts containing significantly higher frequencies of CD4+ T cells coexpressing CD25 than those who did not (median, 9.26% vs 2.22%; P = .004). Frequencies of donor graft CD8+ T cells coexpressing CD25 were also higher (0.65% vs 0.14%; P = .002). Furthermore, transplant recipients who received grafts containing fewer CD4+CD25+ and CD8+CD25+ T cells were less likely to acquire acute GVHD, even though these donor-recipient pairs were similar to others with respect to relevant clinical variables. These data suggest that the coexpression of CD4 and CD25 may be insufficient to identify regulatory T cells in humans and that increased frequencies and numbers of CD25+ T cells in donor grafts is associated with GVHD in transplant recipients. (Blood. 2004;103:1140-1146)
Melamine-Bifunctional Metal Complex: Self-Assembly of High Ordered Organic-Inorganic Sandwich Layers via Hydrogen Bonds and π-π Interactions
Authors: Zhang Yugen , Jianmin Li , Nishiura Masayoshi , Imamoto Tsuneo
Published: August 2003

High ordered organic-inorganic sandwich-type supramolecular architecture [Cu(H2NTA)Cl]·2melamine·2H2O (NTA = nitrilotriacetic acid) which was assembled through double hydrogen bond arrangements of melamine-melamine and melamine-inorganic complex and also through π-π stacking is designed and X-ray structure characterized.
Electron Transfer from Zn- Protoporphyrin IX to Ruthenium Ammine Attached at His63 of Reconstituted Cytochrome b562
Authors: Hamachi Itaru , Takashima Hiroshi , Tsukiji Shinya , Shinkai Seiji , Nagamune Teruyuki , Oishi Shigero
Published: August 2003

Site-specific modification of Cytochrome b562 with ruthenium ammine (RuA5) at 63-His was successfully carried out. Electron transfer rate from ZnPP in the heme crevice to Ru(III)A5 coordinated to 63-His on the protein surface was determined by the laser flash photolysis.
2,6-Di-tert-butyl-4-diarylmethylene-2,5-cyclohexadiene-1-thiones. First Isolable Unannelated Thioquinone Methides
Authors: Suzuki Riho , Kurata Hiroyuki , Kawase Takeshi , Oda Masaji
Published: August 2003

Unannelated thioquinone methides were first synthesized as labile but isolable substances with aid of steric protection; they exhibit higher dipolar properties and stronger electron affinity than the corresponding quinone methides.
Characteristic Behavior of Chemisorbed Oxygen towards CO on Ag Surface
Authors: Tamaru Kenzi
Published: August 2003

When oxygen reacts with CO on Ag surface, the silver surface is fully coveed by oxygen, but only a limited part of the chemisorbed oxygen participates in the reaction. Such characteristic behavior was discussed on the basis of STM observation.
Excellent Stability of Ruthenium(II) Complex Photosensitizers during Photo-Oxidation of 1,3-Cyclopentadiene
Authors: Suzuki Masahiro , Bartels Oliver , Gerdes Robert , Schneider Gerhard , Wöhrle Dieter , Schulz-Ekloff Günter , Kimura Mutsumi , Hanabusa Kenji , Shirai Hirofusa
Published: August 2003

Tris(2,2′-bipyridine)ruthenium(II) and partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes have excellent stability during the photo-oxidation of 1,3-cyclopentadiene and can be sufficiently and repeatedly used as photosensitizers.
Comparison of Nd-Fe-B Surfaces Treated by Chemical Etching in the Absence and Presence of a Magnetic Field
Authors: Kishioka Shin-ya , Aogaki Ryoichi , Nakagawa Jun
Published: August 2003

The effect of magnetic field on a chemical etching of Nd-Fe-B material for permanent magnets was investigated. During magnetization, the dissolution of the material by etching was increased and the surface became flat compared with that by the etching in the absence of a magnetic field.
Synthesis and Molecular Structures of Novel Isopropyl-substituted Oligosilanes
Authors: Tanaka Ryoji , Unno Masafumi , Matsumoto Hideyuki
Published: August 2003

The cyclotetrasilane [(i-Pr)2Si]4 reacts with K in benzene in the presence of 18-crown-6 to give the 1,4-dipotassio compound K[(i-Pr)2Si]4 K (1). The reaction of 1 with (i-Pr)2SiCl2 and Me3SiCl leads to the formation of the sterically crowded oligosilanes, [(i-Pr)2Si]5 (2) and Me3Si[(i-Pr)2Si]4SiMe3 (3), respectively. The molecular structures of the resulting oligosilanes, 2 and 3, display some unusual features.
Photoinduced Deposition of Size-Controlled Gold Nanoclusters onto the Self-Assembled Monolayer of 1,9-Nonanedithiol
Authors: Sumida Takayuki , Murakoshi Kei , Yanagida Shozo
Published: August 2003

Gold nanoclusters are formed photochemically in organic solvent to give nanometer-scale islands on the self-assembled monolayer (SAM) of 1,9-nonanedithiol. The size and shape are variable by choosing electron-donating organic solvents. In ethanol, the plate-like nanoclusters are produced with layer-by-layer growth to give atomically flat top. The nano-structures are formed in N,N-dimethylformamide to give larger size than those in ethanol under comparable conditions.
Computational Studies on the Reactions of N2O with O(3P) and CO
Authors: Tsuchiya Kentaro , Kamiya Kenshu , Shiina Hiroumi , Oya Masaaki
Published: August 2003

We performed ab initio molecular orbital calculations to derive rate expressions for the reactions of N2O with O(3P) and CO. Major products of the O(3P) + N2O reactions are predicted to be NO + NO. Comparisons of calculated and experimental rate constants indicate good agreement exists with the most recent experimental values.
Synthesis, Crystal Structure and Non-linear Optical Properties of [WSe4{Cu(dppm)}4][ClO4]2·MeCN
Authors: Zhang Qian-Feng , Raj S Shanmuga Sundara , Fun Hoong-Kun , Xin Xin-Quan
Published: August 2003

The reaction of Cu(MeCN)4[ClO4], dppm (bis(diphenylphosphino)methane) and [Et4N]2[WSe4] in DMF-CH2Cl2, affords the cationic cluster [WSe4{Cu(dppm)}4]2+ whose structure was shown by X-ray analysis that four edges of the tetrahedral WSe4 core are bridged by a square arrangement of four Cu(I) atoms with the dppm ligands bridging the edges. The cluster compound exhibits a strong optical limiting effect with threshold of 0.3 J·cm−2.
Origin of π-Facial Diastereoselection in Hydride Reduction of Piperidones. The Importance of Ground-State Effects
Authors: Tomoda Shuji , Senju Takatoshi
Published: August 2003

The exterior frontier orbital extension model (the EFOE Model) strongly suggested that the ground-state conformation (steric effects) and the anisotropic frontier orbital (LUMO) extension over π-faces may be the origin of the π-facial diastereoselection in hydride reductions of substituted piperidones.
Excellent Activity of Ultrafine Co-B Amorphous Alloy Catalyst in Glucose Hydrogenation
Authors: Li Hui , Li Hexing , Wang Weijiang , Deng Jing-Fa
Published: August 2003

The ultrafine Co-B amorphous alloy, doped or undoped with Mo or W, were prepared by chemical reduction with borohydride. Its catalytic performance in liquid phase hydrogenation of glucose to sorbitol has been investigated, which revealed (i)the higher activity than that of crystalline Co and the Ni-based catalysts, and (ii)the promoting effect of Mo and W dopants on the activity.
p-Benzoquinone 2,3,5,6-Tetrakis(diisopropyl phosphonate): A Novel, Highly Bent p-Benzoquinone
Authors: Kobiro Kazuya , Shi Min , Inoue Yoshihisa
Published: August 2003

Multiple introduction of phosphonate groups around the quinone oxygen greatly deforms the p-benzoquinone ring through the steric and electronic repulsion. The repulsion produces not a boat but a chair conformation with a bent angle as large as 17.8°.
Tautomerism of a Nitro Derivative of N-Salicylideneaniline in Crystals
Authors: Ogawa Keiichiro , Fujiwara Toshikatsu
Published: August 2003

X-Ray crystallographic and electronic absorption spectroscopic studies on N-(2-hydroxy-3-nitrobenzylidene)aniline revealed that this compound exists as a mixture of the OH and NH forms with nearly the equal populations in crystals.
Unusual Products of Enamines with [60]Fullerene
Authors: Gao Xiang , Ma Sheng-Lei , Guo Li-Wei , Zhang Dan-Wei , Wu Shi-Hui , Wu Hou-Ming , Li Yong-Jiang
Published: August 2003

Unusual products were isolated from reactions of [60]fullerene with cyclopentenyl or cyclohexenyl pyrrolidine and piperidine. The structures of products were characterized by spectroscopic means. A possible thermoinduced electron-transfer mechanism for the new reaction was proposed.
[2,3]-Wittig Rearrangement Initiated by 1,5-Hydrogen Atom Transfer from an o-Iodophenyl Group on the α-Carbon of Allylic Ethers by Reduction with SmI2
Authors: Kunishima Munetaka , Hioki Kazuhito , Nakata Daisuke , Nogawa Shigenobu , Tani Shohei
Published: August 2003

Intramolecular 1,5-hydrogen atom transfer of an aryl radical generated by reduction of an o-iodophenyl group on the allylic position of allyl ethers by SmI2 regioselectively generates α-allyloxy carbanions, which undergo [2,3]-Wittig rearrangement to afford a substituted 4-phenyl-3-buten-1-ol. The effect of HMPA concentration on distribution of the 1,5-hydrogen transfer giving Wittig rearranged products and hydrogen abstraction giving reductive deiodination products is described.
Formation of a Palladalactone Complex by C–O Bond Cleavage of Diketene Promoted by a Zerovalent Palladium Complex
Authors: Kakino Ryuki , Nagayama Kazuhiro , Kayaki Yoshihito , Shimizu Isao , Yamamoto Akio
Published: August 2003

The reaction of diketene with [Pd(PMe3)2(styrene)] 1 at room temperature gave ([Pd(OCOCH2C=CH2)(PMe3)2]) 2 through cleavage of the C–O bond adjacent to the carbon bearing the exomethylene group. The structure of 2 was fully established by spectroscopic means, elemental analysis and single-crystal X-ray analysis. The reactivity of 2 has been investigated.
Highly Diastereoselective Aldol Synthesis from α-Iodo Ketones in Aqueous Media
Authors: Shibata Ikuya , Kawasaki Masatsugu , Yasuda Makoto , Baba Akio
Published: August 2003

Highly diastereoselective aldol synthesis from α-iodo ketones was promoted under aqueous conditions by a distannane system, (n-Bu3Sn)2, n-Bu2SnF2 and HMPA. Aqueous solutions of acetaldehyde, formaldehyde and pivaraldehyde were applicable to give β-hydroxy ketones effectively.
Microbial 7-OH Epimerisation of Bile Acids
Authors: Dean Mariangela , Fantin Giancarlo , Fogagnolo Marco , Medici Alessandro , Pedrini Paola , Poli Silvia
Published: August 2003

The microbial 7-OH epimerisation of cholic and chenodeoxycholic acids with Xanthomonas maltophilia CBS 827.97 to ursocholic and ursodeoxycholic acids with scarsity of oxygen is described. With normal pressure of oxygen the 7-ketocholic and the 7-ketochenodeoxycholic acids are obtained. No biotransformation is achieved in anaerobic conditions.
Spectrophotometric Studies for Complex Formation of Diammonium 1,4,10,13-Tetraoxa-7,16-diazacycrooctadecane-bis(N-carbodithioate) with Transitional Metal Ions under Coexistence of Alkali Matal Ion and Alkali Earth Matal Ion
Authors: Uehara Nobuo , Honzawa Hideki , Aratake Sachiko , Shimizu Tokuo
Published: August 2003

A new bifuntional ligand, Diammonium 1,4,10,13-tetraoxa-7,16-diazacycrooctadecane-bis(N-carbodithioate), has been synthesized. The UV-spectra of Ni(II)-chelate of the ligand was changed by addition of Na+, K+, Rb+, Cs+ and Mg2+. The composition of Pb(II)-chelate was changed from 1:1 (metal:ligand) to 1:2 by addition of Na+, K+, Cs+, Mg2+, Ca2+ and Sr2+. These changes were produced by the change in the conformation of the diaza-crown ring in the ligand.
High Activity of Pt/AlPO4 Catalyst for Selective Catalytic Reduction of Nitrogen Monoxide by Propene in Excess Oxygen
Authors: Fujii Ryuta , Seki Masashi , Shinoda Jun , Okazaki Noriyasu , Tada Akio
Published: August 2003

The activity of Pt(0.5 wt%)/AlPO4 for C3H6-SCR was found to be much higher than that of Pt(0.5 wt%)/Al2O3; although the selectivity toward N2O of both the catalysts were comparable, the maximal conversion of NO to N2 by Pt(0.5 wt%)/AlPO4 was higher than that by Pt(0.5 wt%)/Al2O3, and moreover the temperature window of the former located in lower side than that of the latter. The superiority of Pt(0.5 wt%)/AlPO4 was discussed on the basis of the results of XPS measurements.
“Syn-Effect” in the Conversion of (E)-α,β-Unsaturated Esters to the Corresponding β,γ-Unsaturated Esters
Authors: Guha Samar Kumar , Shibayama Atsushi , Abe Daisuke , Ukaji Yutaka , Inomata Katsuhiko
Published: August 2003

The stereochemistry in the conversion of (E)-α,β-unsaturated esters to the corresponding β,γ-unsaturated esters by treatment with lithium hexamethyldisilazide in the presence of HMPA was investigated. The Z/E ratios of the resulting β,γ-unsaturated esters varied according to the γ-substituents of the (E)-α,β-unsaturated esters. This phenomenon was rationalized by “syn-effect” which may be attributed primarily to σ→π* interaction and/or 6π-electron homoaromaticity.
Surfactant-free Preparation of Poly(lactic acid)/Hydroxyapatite Microspheres
Authors: Nagata Fukue , Miyajima Tatsuya , Yokogawa Yoshiyuki
Published: August 2003

A novel surfactant-free process were proposed by modifying oil-in-water emulsion method to produce PLA/calcium phosphate composite. Several analyses suggested that the end group of PLA would play as the nucleation site for calcium phosphate precipitates at the oil/water interface. The precipitated calcium phosphate might play a role as stabilizer for microsphere fabrication.
113Cd MAS and Static NMR Study of Chlorocadmate Glasses
Authors: Sakida Shinichi , Nakata Hironobu , Kawamoto Yoji
Published: August 2003

113Cd magic-angle spinning (MAS) and static NMR spectra were measured of fourteen kinds of chlorocadmate glasses to reveal the chlorine coordination environments around Cd2+ in the glasses in detail. The spectra of the glasses suggest that the glass structures are mainly composed of infinite double-chains of edge-shared CdCl6 octahedra, being independent of the CdCl2 content and the kinds of chlorides except for CdCl2. 113Cd MAS and static NMR spectroscopies enabled us to reveal not only chlorine coordination number of Cd but also linkage manners between CdCl6 octahedra in the glasses.
Carbonaceous Deposit as a Preferential Reductant in the Reduction of NO with C2H4 in Excess Oxygen over Alumina
Authors: Fujii Ryuta , Kitagawa Sayaka , Takahashi Kou , Okazaki Noriyasu , Tada Akio
Published: August 2003

Carbonaceous deposit (denoted as C(d)) which was formed on alumina by C2H4 pyrolysis at 550 °C reacted selectively and preferentially with a mixture of NO and O2 in the presence of C2H4, suggesting that the C(d) acts as an effective intermediate during the selective reduction of NO with C2H4 too.
Anion Recognition at the Solid/Liquid Interface as Studied by Second Harmonic Generation Spectroscopy
Authors: Yamaguchi Akira , Kato Ryo , Nishizawa Seiichi , Teramae Norio
Published: August 2003

A self-assembled monolayer of thiourea-based anion receptor was formed at a gold surface, and its affinity with monovalent inorganic anions (MeCO2−, H2PO4−, Cl−) in acetonitrile solution was examined by second harmonic generation spectroscopy. The estimated adsorption coefficients of anions at the monolayer reveal specific binding selectivity compared with the selectivity found in a bulk acetonitrile phase.
Polypyrrole–metal Coil Composites as Fibrous Artificial Muscles
Authors: Hara Susumu , Zama Tetsuji , Sewa Shingo , Takashima Wataru , Kaneto Keiichi
Published: August 2003

A polypyrrole deposited electrochemically on tungsten coil showed 11.6% strain and 0.20 N force induced electrochemically. The W coil significantly reduced iR drop of the PPy, resulting in improving performance of the actuator. The fibrelike structure was suitable for applications of artificial muscles.
Solution-mediated Synthesis of a Three-dimensional Zincophosphate in the Presence of Racemic 1,2-Diaminopropane
Authors: Xing Yan , Liu Yunling , Li Guanghua , Shi Zhan , Liu Li , Meng He , Pang Wenqin
Published: August 2003

A three-dimensional zinc phosphate [Zn2(HPO4)3][C3N2H12], I, has been solvothermally synthesized templated by racemic 1,2-diaminopropane; its structure consists of vertex-linking ZnO4, and HPO4 tetrahedral units forming channels bound by 8- and 12-T atoms (T = Zn, P). The enantiomers of 1,2-diaminopropane are separated as R and S configuration in the alternating 8-membered channels.
Salt-assisted Solid-state Chemical Reaction. Synthesis of ZnO Nanocrystals
Authors: Shen Liming , Guo Luchun , Bao Ningzhong , Yanagisawa Kazumichi
Published: August 2003

By adopting a room-temperature grinding of the zinc acetate–oxalic acid powder mixture and a subsequent thermal decomposition reaction, agglomerated ZnO nanocrystals with diameters of 15–40 nm were prepared. By adding NaCl in the whole process, well-dispersed ZnO nanocrystals with diameters of 3–4 nm, showing an obvious blue shift due to the size quantization effect, were prepared.
Total Synthesis of α-Ketol Derivative of Linolenic Acid (KODA), a Flower-inducing Factor in Lemna paucicostata
Authors: Yokokawa Yoshihiro , Kobayashi Kouji , Yokoyama Mineyuki , Yamamura Shosuke
Published: August 2003

Racemic 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid [(±)-KODA] was synthesized via a coupling reaction between a diyne and an epoxide derived from methyl oleate as a key step. An optically active 9R-KODA was also synthesized by enantioselective lipase-catalyzed esterification of an allyl alcohol. Both synthetic (±)-KODA and 9R-KODA showed remarkable flower-inducing activity in Pharbitis nil.
Ontogeny of the nasopalatine duct in primates
Authors: Shimp Kristin L. , Bhatnagar Kunwar P. , Bonar Christopher J. , Smith Timothy D.
Published: August 2003

Ecological explanations have been put forward to account for the precocious or delayed development of patency in ducts leading to the vomeronasal organ (VNO) in certain mammals. Perinatal function may be related, in part, to the patency or fusion of the vomeronasal and nasopalatine (NPD) ducts. However, few studies have focused on NPD development in primates, which generally have a prolonged period of dependence during infancy. In this study we examined 24 prenatal primates and 13 neonatal primates, and a comparative sample of fetal mice and insectivores. In embryonic and early fetalMicrocebus murinus, the NPD was completely fused, whereas in fetuses of later stages the duct was partially fused or completely patent.M. myoxinusof all stages demonstrated some degree of NPD fusion. In all other prenatal primates, the NPD was fused to some extent. Four prenatal insectivores (Tenrec ecaudatus) showed some degree of NPD fusion. InMus musculusat 19 days gestation, the NPD was patent, although the anatomically separate VNO duct was fused.T. ecaudatusand most of the neonatal primates revealed complete NPD patency. An exception wasSaguinus geoffroyi, which exhibited fusion of the NPD near the VNO opening. These observations may relate to differences in perinatal VNO function. The differences noted in our study suggest thatM. murinusandM. myoxinusmay differ in perinatal VNO functionality and perhaps in related behavior. Observations of neonatal primates suggest that NPD patency may be relatively common at birth and could serve other purposes in addition to being an access route for VNO stimuli. Anat Rec Part A 274A:862–869, 2003. © 2003 Wiley‐Liss, Inc.
Selective partial PIC for wireless CDMA communications
Authors: Belloni Filippo , Fantacci Romano , Morosi Simone
Published: August 2003

This paper deals with a cancellation multiuser detector for CDMA communication systems. The proposed receiver, defined as selective partial parallel interference cancellation (SP‐PIC), is supposed to be used at the end of an up‐link channel characterized by multipath fading phenomena. The SP‐PIC main feature is to perform a weighted selective cancellation of the co‐channel interfering signals according to the received power level. With respect to other approaches, the proposed detector exhibits an improved bit error rate (BER) and a low computational complexity, linear with the number of users. Copyright © 2003 John Wiley & Sons, Ltd.
Performability modelling of wireless communication systems
Authors: Trivedi Kishor S. , Ma Xiaomin , Dharmaraja S.
Published: August 2003

The high expectations of performance and availability for wireless mobile systems has presented great challenges in the modelling and design of fault tolerant wireless systems. The proper modelling methodology to study the degradation of such systems is so‐calledperformabilitymodelling. In this paper, we give overview of approaches for the construction and the solution of performability models for wireless cellular networks. First, we start with the Erlang loss model, in which hierarchical and composite Markov chains are constructed to obtain loss formulas for a system with channel failures. Consequently, we develop two level hierarchical models for the wireless cellular system with handoff and channel failures. Then, for a TDMA system consisting of base repeaters and a control channel, we build a hierarchical Markov chain model for automatic protection switching (APS). Finally, we discuss stochastic reward net (SRN) models for performability analysis of wireless systems. Copyright © 2003 John Wiley & Sons, Ltd.
Morphometric analysis and tectonic interpretation of digital terrain data: a case study
Authors: Jordan Gyozo
Published: August 2003

Tectonic movement along faults is often reﬂected by characteristic geomorphological features such as linear valleys, ridgelines and slope‐breaks, steep slopes of uniform aspect, regional anisotropy and tilt of terrain. Analysis of digital elevation models, by means of numerical geomorphology, provides a means of recognizing fractures and characterizing the tectonics of an area in a quantitative way. The objective of this study is to investigate the use of numerical geomorphometric methods for tectonic geomorphology through a case study. The methodology is based on general geomorphometry. In this study, the basic geometric attributes (elevation, slope, aspect and curvatures) are complemented with the automatic extraction of ridge and valley lines and surface speciﬁc points. Evans' univariate and bivariate methodology of general geomorphometry is extended with texture (spatial) analysis methods, such as trend, autocorrelation, spectral, and network analysis. Terrain modelling is implemented with the integrated use of: (1) numerical differential geometry; (2) digital drainage network analysis; (3) digital image processing; and (4) statistical and geostatistical analysis. Application of digital drainage network analysis is emphasized. A simple shear model with principal displacement zone with an NE–SW orientation can account for most of the the morphotectonic features found in the basin by geological and digital tectonic geomorphology analyses. Copyright © 2003 John Wiley & Sons, Ltd.