bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis of remyelinating potential of focal and intravenous administration of autologous bone marrow cells into the rat demyelinated spinal cord
Authors: Inoue Michio , Honmou Osamu , Oka Shinichi , Houkin Kiyohiro , Hashi Kazuo , Kocsis Jeffery D.
Published: October 2004

The remyelinating potential of autologous bone marrow cells was studied after direct injection and following intravenous injection into rats with a demyelinated lesion in the spinal cord. Both focal and intravenous injections of acutely isolated mononuclear bone marrow cell fractions resulted in varying degrees of remyelination. Suspensions of bone marrow cells collected from the same rat were delivered at varied concentrations (102 to 105 for direct injection and 104 to 107 for i.v. injections). The lesions were examined histologically 3 weeks after transplantation. Light microscopic examination revealed remyelination in the dorsal funiculus with both injection protocols, but the extent of remyelination was proportional to the number of injected cells. To attain the same relative density of remyelination achieved by direct injection, intravenous administration of cells required delivery of substantially more cells (two orders of magnitude). However, the availability of autologous bone marrow cells in large number and the potential for systemically delivering cells to target lesion areas without neurosurgical intervention suggest the potential utility of intravenous cell delivery as a prospective therapeutic approach in demyelinating disease. © 2003 Wiley‐Liss, Inc.
In vitro cytocompatibility assessment of β‐tricalcium phosphate/carboxymethyl‐chitin composite
Authors: Muramatsu Kazuaki , Nakajima Madoka , Kikuchi Masanori , Shimada Sawako , Sasaki Kiyoshi , Masuda Shingo , Yoshihara Yusuke
Published: October 2004

A novel bioabsorbable bone substitute composed of a β‐tricalcium phosphate (β‐TCP) and a carboxymethyl‐chitin (CM‐chitin) sodium has been developed. Rabbit tibia defects (4 mm in diameter) were repaired after 4 weeks more effectively by the composite compared with a sham‐operation group. To further investigate the biological safety of the components, genotoxicity and carcinogenicity of an extract prepared from the composite were determined using four different in vitro assays. The main extract component was identified as CM‐chitin sodium [average molecular weight (Mw) ∼230 kDa] as determined by Fourier transform infrared spectroscopy and gel permeation chromatography analysis. The concentrations of P and Ca possibly derived from β‐TCP were 17.7 and 37.1 μg/g, respectively, as determined by inductively coupled plasma mass spectroscopy. Both the metabolic activation and nonactivation (−S9) systems of the rat microsome S9 fraction were used to perform a genotoxicity evaluation using the Ames test and chromosome aberration assay on Chinese hamster lung fibroblast cells treated with the extract. In these assays, no genotoxicity was detected with doses ≤5 mg/mL (maximum concentration). The cell transformation assay using BALB/c 3T3 cells and the metabolic cooperation assay with V79 cells both showed negative results for any tumor‐promoting activity caused by the extract (∼5 mg/mL). These results indicate that the bioabsorbable β‐TCP/CM‐chitin composite is a highly biocompatible bone substitute. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 635–643, 2004
Large‐volume leukapheresis using femoral venous access for harvesting peripheral blood stem cells with the Fenwal CS 3000 Plus from normal healthy donors: Predictors of CD34+ cell yield and collection efficiency
Authors: Sohn Sang Kyun , Kim Jong Gwang , Chae Yeo Soo , Kim Dong Hwan , Lee Nan Young , Suh Jang Soo , Lee Kyu Bo
Published: October 2004

The current paper reports on the predicting factors associated with satisfactory peripheral blood stem cell collection and the efficacy of large‐volume leukapheresis (LVL) using femoral vein catheterization to harvest PBSCs with Fenwal CS 3000 Plus from normal healthy donors for allogeneic transplantation. A total of 113 apheresis procedures in 57 patients were performed. The median number of MNCs, CD3+ cells, and CD34+ cells harvested per apheresis was 5.3 × 108/kg (range, 0.3–11.0 × 108/kg), 3.0 × 108/kg (range, 0.2–6.6 × 108/kg), and 7.9 × 106/kg (range, 0.1–188.9 × 106/kg), respectively. The median collection efficiency of MNCs and CD34+ cells was 49.8% and 49.7%, respectively. A highly significant correlation was found between the collected CD34+ cell counts and the pre‐apheresis WBC counts in the donors (P = 0.013), and between the collected CD34+ cell counts and the pre‐apheresis peripheral blood (PB) CD34+ cell counts (P<0.001). Harvesting at least >4 × 106/kg CD34+ cells from the 1st LVL was achieved in 44 (77.2%) out of 57 donors and in 19 (90.5%) out of 21 donors with a PB‐CD34+ cell count of >40/μl. There was no significant difference in the harvested MNC and CD34+ cell counts between the 1st and 2nd apheresis. The catheter‐related complications included catheter obstruction (n = 2) and hematoma at the insertion site (n = 3). Accordingly, LVL using femoral venous access for allogeneic PBSC collection from normal healthy donors would appear to be safe and effective. J. Clin. Apheresis 18:10–15, 2003. © 2003 Wiley‐Liss, Inc.
Twenty‐first‐century check clearing: Are you ready?
Authors: Burnie David A. , Hurtt David , Langsam Sheldon A.
Published: October 2004

The terrorist attacks of 9/11 showed how easy it was to severely disrupt our banking system. The grounding of air flights delayed the transportation
of millions of checks—causing the Federal Reserve Bank's check float to balloon to more than 100 times its normal level.

To protect our banking system, Congress passed the Check 21 Act. But what will be the impact on businesses, consumers, and financial institutions? What potential problems will companies face? And what steps can you take to get ready for Check 21? The authors take a close look at these issues and provide some answers. © 2004 Wiley Periodicals, Inc.
Finding cash in the back office
Authors: Reder Dan
Published: October 2004

New approaches to treasury management not only improve cash flow and simplify accounting—they can also save you a lot of money and significantly reduce risk. Improved contract management (CM) software, states the author, offers a high yield and quick payback for treasury managers eager to cut costs. The author explains how CM software works and what to look for when you shop for it. © 2004 Wiley Periodicals, Inc.
Cost reduction analysis: A benchmarking guide for treasury managers
Authors: Reider Rob
Published: October 2004

Treasury managers know that strong sales and timely collections are major contributors to cash flow. But effective cost reduction can be an even greater contributor, argues the author of this article. And he presents a detailed guide to using benchmarking for cost reduction. © 2004 Wiley Periodicals, Inc.
Accounts receivable conversion: Should you do it?
Authors: Latham Lanny
Published: October 2004

Does your company receive high volumes of consumer check payments through the mail? If so, your firm might benefit significantly from accounts receivable conversion. But how do you tell if it is really right for your company? The author has some answers. © 2004 Wiley Periodicals, Inc.
Capitalizing interest: What does “material” mean?
Authors: Jordan Charles E. , Clark Stanley J.
Published: October 2004

SFAS 34 requires the capitalization of interest as part of the cost of certain assets if the effects of capitalization are deemed material. Yet, U.S. professional standards provide virtually no guidance on what constitutes a material effect. The authors took a close look at recent research and current practice and came up with some simple materiality guidelines for interest capitalization. CEOs and CFOs are now required to certify financial statements; this is enforced with criminal penalties under Sarbanes‐Oxley. So they should read this article carefully. © 2004 Wiley Periodicals, Inc.
Performance management—Making it work
Authors: Cokins Gary
Published: October 2004

Senior managers are often frustrated at their lack of direct control. After all, managers can bring about improvement only by influencing their employees, who sometimes don't manage to do what's best for the company as a whole. The solution to this dilemma is performance management, which provides managers and employee teams at all levels the ability to move directly toward their defined strategies. © 2004 Wiley Periodicals, Inc.
Evaluation of intrarenal oxygenation by BOLD MRI at 3.0T
Authors: Li Lu‐Ping , Vu Anthony T. , Li Belinda S.Y. , Dunkle Eugene , Prasad Pottumarthi V.
Published: October 2004

Purpose

To examine the benefit of using higher field strengths for BOLD MRI to detect changes in renal medullary oxygenation following pharmacological maneuvers.

Materials and Methods

Renal BOLD MRI, primarily at 1.5T, has been shown to be useful for monitoring changes in medullary oxygenation status. We performed the present studies on a 3.0T scanner using a multiple gradient‐echo (mGRE) sequence with a multicoil array to acquire 16 T2*‐weighted images within a single breath‐hold. Data were obtained before and after administration of furosemide (20 mg iv).

Results

The baseline renal R2* (mean ± SE) at 3.0T was 37.4±1.2 Hz in the medulla, and 21.8 ± 1.2 Hz in the cortex. The BOLD response to furosemide (ΔR2*) at 3.0T was 11.8 ± 1.1 Hz in the medulla, and 3.0 ± 0.5 Hz in the cortex.

Conclusion

Higher magnetic field strength is beneficial for renal BOLD MRI studies. The cortico‐medullary contrast on the R2* map was significantly improved at 3.0T, with no evidence of increased bulk susceptibility artifacts. Baseline R2* and ΔR2* in the renal medulla at 3.0T were both significantly higher compared to our previously reported data obtained at 1.5T. J. Magn. Reson. Imaging 2004;20:901–904. © 2004 Wiley‐Liss, Inc.
Respiratory reordered UNFOLD perfusion imaging
Authors: Ablitt Nicholas A. , Gatehouse Peter D. , Firmin David N. , Yang Guang‐Zhong
Published: October 2004

Purpose

To propose a respiratory reordered UNFOLD (RR‐UNFOLD) imaging sequence to significantly reduce the amount of k‐space data required for first‐pass MR myocardial perfusion imaging.

Materials and Methods

Rapid acquisition of high‐resolution imaging data is essential to detailed quantitative analysis of first‐pass myocardial perfusion. Existing MR sequences have explored the full capacity of the imaging hardware to reduce the acquisition window within each cardiac cycle while maintaining the desired spatial resolution. Further improvement in perfusion imaging will require a more efficient use of the information content of the k‐space data. The method uses prospective diaphragmatic navigator echoes to ensure that temporal filtering of UNFOLD is carried out on a series of images that are spatially registered. An adaptive real‐time rebinning algorithm is developed for the creation of static image subseries related to different levels of respiratory motion. Issues concerning the temporal smoothing of tracer kinetic signals are discussed, and a solution based on oversampling of the central k‐space is provided. The method is assessed in 10 normal subjects without the administration of contrast agent, and further validated by administration of Gd‐DTPA in 10 patients at rest.

Results

The results of this study show that RR‐UNFOLD significantly extends the applicability of UNFOLD to perfusion imaging, which yields a 40% reduction in image artifact when the same amount of k‐space information is used.

Conclusion

The scan efficiency achieved can be used in combination with MR hardware improvements for extending the three‐dimensional spatial coverage and shortening the data acquisition window to provide detailed information on regional myocardial perfusion abnormalities. J. Magn. Reson. Imaging 2004;20:817–825. © 2004 Wiley‐Liss, Inc.
Magnetic resonance imaging of knee cartilage using a water selective balanced steady‐state free precession sequence
Authors: Kornaat Peter R. , Doornbos Joost , van der Molen Aart J. , Kloppenburg Margreet , Nelissen Rob G. , Hogendoorn Pancras C.W. , Bloem Johan L.
Published: October 2004

Purpose

To compare an optimized water selective balanced steady‐state free precession sequence (WS‐bSSFP) with conventional magnetic resonance (MR) sequences in imaging cartilage of osteoarthritic knees.

Materials and Methods

Flip angles of sagittal and axial WS‐bSSFP sequences were optimized in three volunteers. Subsequently, the knees of 10 patients with generalized osteoarthritis were imaged using sagittal and axial WS‐bSSFP and conventional MR imaging techniques. We calculated contrast‐to‐noise ratios (CNR) between cartilage and its surrounding tissues to quantitatively analyze the various sequences. Using dedicated software we compared, in two other patients, the accuracy of cartilage volume measurements with anatomic sections of the tibial plateau.

Results

CNRtotal eff (CNR efficiency between cartilage and its surrounding tissue) using WS‐bSSFP was maximal with a 20–25° flip angle. CNRtotal eff was higher in WS‐bSSFP than in conventional images: 6.1 times higher compared to T1‐weighted gradient echo (GE) images, 5.1 compared to proton‐density (PD) fast spin echo (FSE) images, and 4.8 compared to T2‐weighted FSE images. The mean difference of cartilage volume measurement on WS‐bSSFP and anatomic sections was 0.06 mL compared to 0.24 mL for T1‐GE and anatomic sections.

Conclusion

A WS‐bSSFP sequence is superior to conventional MR imaging sequences in imaging cartilage of the knee in patients with osteoarthritis. J. Magn. Reson. Imaging 2004;20:850–856. © 2004 Wiley‐Liss, Inc.
Dynamic near‐real‐time magnetic resonance imaging for analyzing the velopharyngeal closure in comparison with videofluoroscopy
Authors: Beer Ambros J. , Hellerhoff Paul , Zimmermann Angela , Mady Katalin , Sader Robert , Rummeny Ernst J. , Hannig Christian
Published: October 2004

Purpose

To demonstrate the feasibility of dynamic magnetic resonance imaging (MRI) with near‐real‐time temporal resolution (“real‐time MRI”) for analyzing the velopharyngeal closure in comparison with multiview videofluoroscopy.

Materials and Methods

Seven patients (three females and four males, 5–21 years old, mean age = 11.3 years) with suspected velopharyngeal insufficiency, and one healthy volunteer were examined with videofluoroscopy and real‐time MRI using a turbo‐spin‐echo (TSE) sequence (TR = 170 msec, TE = 21 msec, slice thickness = 6 mm, six images per second). Imaging was done during phonation in all three image planes. The results were analyzed by two radiologists in comparison with videofluoroscopy as the standard of reference for overall image quality and the pattern of velopharyngeal closure.

Results

Real‐time MRI correctly depicted the pattern of velopharyngeal closure in correspondence to videofluoroscopy in all cases. Concerning the movement of the pharyngeal walls, real‐time MRI falsely depicted a general movement of the dorsal pharyngeal wall in one case, whereas videofluoroscopy showed no movement. In one patient, real‐time MRI provided additional information by showing an asymmetric movement of the lateral pharyngeal walls that could not be depicted by videofluoroscopy due to technical limitations. Concerning image quality, the coronal plane was more difficult to evaluate with real‐time MRI compared to videofluoroscopy. The axial plane was easier to analyze in real‐time MRI compared to videofluoroscopy.

Conclusion

Real‐time MRI has the potential to depict the pattern of velopharyngeal closure in close correlation with videofluoroscopy, and may deliver additional information in selected cases. J. Magn. Reson. Imaging 2004;20:791–797. © 2004 Wiley‐Liss, Inc.
Profound increase in sensitivity to glutamatergic‐ but not cholinergic agonist‐induced seizures in transgenic mice with astrocyte production of IL‐6
Authors: Samland Helen , Huitron‐Resendiz Salvador , Masliah Eliezer , Criado Jose , Henriksen Steven J. , Campbell Iain L.
Published: October 2004

Transgenic mice with glial fibrillary acidic protein (GFAP) promoter driven‐astrocyte production of the cytokines interleukin‐6 (IL‐6) and tumor necrosis factor (TNF) were used to determine whether the pre‐existing production of these cytokines in vivo might modulate the sensitivity of neurons to excitotoxic agents. Low doses of kainic acid (5 mg/kg) that produced little or no behavioral or electroencephalogram (EEG) alterations in wild type or glial fibrillary acidic protein (GFAP)‐TNF animals induced severe tonic‐clonic seizures and death in GFAP‐IL6 transgenic mice of 2 or 6 months of age. GFAP‐IL6 mice were also significantly more sensitive to N‐methyl‐D‐aspartate (NMDA)‐ but not pilocarpine‐induced seizures. Kainic acid uptake in the brain of the GFAP‐IL6 mice was higher in the cerebellum but not in other regions. Kainic acid binding in the brain of GFAP‐IL6 mice had a similar distribution and density as wild type controls. In the hippocampus of GFAP‐IL6 mice that survived low dose kainic acid, there was no change in the extent of either neurodegeneration or astrocytosis. Immunostaining revealed degenerative changes in gamma aminobutyric acid (GABA)‐ and parvalbumin‐positive neurons in the hippocampus of 2‐month‐old GFAP‐IL6 mice which progressed to the loss of these cells at 6 months of age. Thus, GFAP‐IL6 but not GFAP‐TNF mice showed markedly enhanced sensitivity to glutamatergic‐ but not cholinergic‐induced seizures and lethality. This may relate, in part, to a compromise of inhibitory interneuron function. Therefore, pre‐existing IL‐6 production and inflammation in the central nervous system (CNS) not only causes spontaneous neurodegeneration but also synergizes with other neurotoxic insults to induce more severe acute functional neurological impairment. © 2003 Wiley‐Liss, Inc.
Characterisation of a sphingosine 1‐phosphate‐activated Ca2+ signalling pathway in human neuroblastoma cells
Authors: Villullas Israel Ramos , Smith Alison J. , Heavens Robert P. , Simpson Peter B.
Published: October 2004

Sphingosine 1‐phosphate (S1P) has assumed great importance within neuroscience research because of putative links between S1P‐sensitive Edg receptors and neuroregeneration, cell survival, and alterations in neurite outgrowth. In the present study, we examined the mechanisms by which the endogenous complement of S1P‐sensitive human Edg receptors can elevate Ca2+ in the human neuroblastoma cell line, SH‐SY5Y. Reverse transcriptase‐polymersase chain reaction (RT‐PCR) confirmed the expression of mRNA for Edg 3, 5, and 8 subtypes of S1P‐responsive Edg receptors in SH‐SY5Y cells. Neither S1P nor the muscarinic agonist methacholine were able to cause a change in SH‐SY5Y cell morphology, whereas retinoic acid caused a range of changes, including an increase in neurite outgrowth, under similar test conditions. Stimulation with S1P resulted in a slowly rising increase in cytosolic Ca2+ levels. These responses were dependent upon inositol‐1,4,5‐trisphosphate receptors, thapsigargin‐sensitive endoplasmic reticulum, and also intact functional mitochondria. S1P‐evoked Ca2+ responses were similar in mechanism to those of methacholine, which activated a much faster responding, larger amplitude Ca2+ response. These studies indicate that in an endogenous human expression system, S1P appears to be an efficacious agonist of Edg receptors. Despite its slow time course of response, S1P appears to activate the same single Ca2+ store in SH‐SY5Y cells as is activated by methacholine and other G protein coupled receptors. © 2003 Wiley‐Liss, Inc.
Presenilin 1 mediates retinoic acid‐induced differentiation of SH‐SY5Y cells through facilitation of Wnt signaling
Authors: Uemura Kengo , Kitagawa Naoyuki , Kohno Ryuichi , Kuzuya Akira , Kageyama Takashi , Shibasaki Hiroshi , Shimohama Shun
Published: October 2004

Presenilin 1 interacts with β‐catenin, an essential component of the Wnt signaling pathway. To elucidate the role of presenilin 1‐β‐catenin interaction in neuronal differentiation, we established SH‐SY5Y cells stably expressing wild‐type presenilin 1, P117L mutant presenilin 1, which is linked to the early‐onset familial form of Alzheimer's disease, and D385A mutant presenilin 1, which has no aspartyl proteinase activity. We demonstrate that SH‐SY5Y cells stably expressing D385A mutant presenilin 1 failed to differentiate in response to retinoic acid treatment. Retinoic acid caused an increase in nuclear β‐catenin levels in SH‐SY5Y cells, which was followed by an increase in cyclin D1 protein levels. Abnormal cellular accumulation of β‐catenin was observed in D385A mutant transfected cells, whereas nuclear β‐catenin and cellular cyclin D1 levels failed to increase. Conversely, SH‐SY5Y cells expressing the P117L mutant differentiated normally and showed increased nuclear β‐catenin and cellular cyclin D1 levels. These findings suggest that neuronal differentiation of SH‐SY5Y cells involves the Wnt signaling pathway and that presenilin 1 plays a crucial role in Wnt signal transduction by regulating the nuclear translocation of β‐catenin. © 2003 Wiley‐Liss, Inc.
ERK and SAPK signaling in auditory brainstem neurons after unilateral cochlear ablation
Authors: Suneja Sanoj K. , Potashner Steven J.
Published: October 2004

Unilateral cochlear ablation (UCA) in adults deafferented one cochlear nucleus (CN) and induced several plasticities in central auditory pathways. To assess whether signal transduction could contribute to these changes, we determined if UCA induced activity in the extracellular signal‐regulated kinase (ERK) and the stress‐activated protein kinase (SAPK) signal transduction pathways. Using Western blots, we measured phosphorylated ERK1 (ERK1‐P), ERK2 (ERK2‐P), p46 and p54 SAPK (SAPK‐P) and c‐Jun (c‐Jun‐P) levels in the major subdivisions of the CN, the principal nuclei of the superior olivary complex (SOC) and the central nucleus of the inferior colliculus (ICc) for up to 145 days postablation. ERK1‐P and ERK2‐P were typically elevated at 7 and 145 days but depressed at 30 days, 60 days, or both. In addition, ERK1‐P and ERK2‐P were elevated at 3 days in the anteroventral (AVCN) and posteroventral CN (PVCN). Immunohistochemical labeling indicated that after 5 days, most ERK1/2‐P in the CN was in neuronal nuclei. Only minor changes were evident in total ERK1 and ERK2 levels. Several correlations were evident between the postablation plasticities observed previously and altered ERK1‐P and ERK2‐P levels. Few changes were found in SAPK‐P and c‐Jun‐P levels. Concomitant elevations of SAPK‐P and c‐Jun‐P were not evident, except in the superficial dorsal CN (DCN) at postablation day 3, consistent with a cell‐stress response. These findings suggest that signals induced as a consequence of UCA are transduced mainly through the neuronal ERK pathway. This activity probably influenced gene expression and cytoplasmic regulatory mechanisms that contributed to the plasticities induced by UCA. © 2003 Wiley‐Liss, Inc.
Pyruvate protection against β‐amyloid‐induced neuronal death: Role of mitochondrial redox state
Authors: Alvarez Gema , Ramos Milagros , Ruiz Francisca , Satrústegui Jorgina , Bogónez Elena
Published: October 2004

The mechanism by which β‐amyloid protein (Aβ) causes degeneration in cultured neurons is not completely understood, but several lines of evidence suggest that Aβ‐mediated neuronal death is associated with an enhanced production of reactive oxygen species (ROS) and oxidative damage. In the present study, we address whether supplementation of glucose‐containing culture media with energy substrates, pyruvate plus malate (P/M), protects rat primary neurons from Aβ‐induced degeneration and death. We found that P/M addition attenuated cell death evoked by β‐amyloid peptides (Aβ25–35 and Aβ1–40) after 24 hr treatment and that this effect was blocked by α‐ciano‐3‐hydroxycinnamate (CIN), suggesting that it requires mitochondrial pyruvate uptake. P/M supply to control and Aβ‐treated neuronal cultures increases cellular reducing power, as indicated by the ability to reduce the dye 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT). The early increases in ROS levels, measured by dichlorofluorescein (DCF) fluorescence, and caspase‐3 activity that follow exposure to Aβ were notably reduced in the presence of P/M. These results place activation of caspase‐3 most likely downstream of oxidative damage to the mitochondria and indicate that mitochondrial NAD(P) redox status plays a central role in the neuroprotective effect of pyruvate. Inhibition of respiratory chain complexes and mitochondrial uncoupling did not block the early increase in ROS levels, suggesting that Aβ could initiate oxidative stress by activating a source of ROS that is not accesible to the antioxidant defenses fueled by mitochondrial substrates. © 2003 Wiley‐Liss, Inc.
Protective role of the cytokine‐inducible isoform of nitric oxide synthase induction and nitrosative stress in experimental autoimmune encephalomyelitis of the DA rat
Authors: Kahl Kai G. , Zielasek Jürgen , Uttenthal L. Otto , Rodrigo Jose , Toyka Klaus V. , Schmidt Harald H.H.W.
Published: October 2004

The pathogenic role of nitric oxide (NO) in multiple sclerosis (MS) remains controversial. Some groups have reported a pathogenic role of NO in experimental autoimmune encephalomyelitis (EAE), an animal model of some aspects of MS, whereas we and others have found a disease‐suppressive effect of NO in EAE. Because the previously used EAE models have a mainly monophasic inflammatory disease course, distinct from MS, we here studied EAE in the DA rat, which better models the demyelinating and relapsing disease course of human MS. The induction of EAE in DA rats led to 1) severe inflammatory infiltrates mainly in the lumbar spinal cord; 2) an up‐regulation of the activity of the cytokine‐inducible isoform of NO synthases (NOS‐II); and 3) increased tissue protein tyrosine nitration, as indicated by peroxynitrite (ONOO−), as a marker of nitrosative stress. Sources of superoxide metabolism, i.e., NADPH oxidase, myeloperoxidase, and superoxide dismutase, remained unchanged. Early treatment of animals with aminoguanidine, a relatively selective inhibitor of NOS‐II, lowered nitrotyrosine immunoreactivity but at the same time led to more severe disease and pronounced inflammatory infiltrates in the lumbar spinal cord. Our results suggest a rather protective role of NOS‐II induction and nitrosative stress in EAE in DA rats and support the hypothesis of a disease‐mitigating immunomodulatory role of NO in this animal model of MS. © 2003 Wiley‐Liss, Inc.
β‐amyloid peptide binding protein does not couple to G protein in a heterologous Xenopus expression system
Authors: Lee Yong , Chang Deok‐Jin , Lee Yong‐Seok , Chang Keun‐A , Kim Hyoung , Yoon Jeung‐Sook , Lee Seungbok , Suh Yoo‐Hun , Kaang Bong‐Kiun
Published: October 2004

Alzheimer's disease is a neurodegenerative disorder related to the formation of protein aggregates. β‐Amyloid protein (Aβ), generated by enzymatic cleavage of amyloid precursor protein (APP), can cause such aggregation, and these aggregates may cause neuronal cell death by inducing apoptosis. However, Aβ‐induced intracellular signaling pathways involved in the neuronal death are not well understood. Recently it was shown that Aβ aggregates induce neuronal cell death via β‐amyloid peptide‐binding protein (BBP), a receptor for Aβ in BBP‐transfected cells, which is known to be sensitive to pertussis toxin, a Gαi/o family inhibitor. However, the actual coupling of BBP to the pertussis‐sensitive G protein was not demonstrated. In this study, we performed electrophysiological recordings using the two‐electrode voltage‐clamp technique to test whether human or Drosophila BBPs, singly or in combination with APP, are coupled to a specific type of G protein. Our results suggest that BBP is not directly coupled to Gαi/o, Gαs, or Gαq proteins and that BBP may need a component other than APP to exert its toxic effect in concert with Aβ. © 2003 Wiley‐Liss, Inc.
Diazoxide pretreatment induces delayed preconditioning in astrocytes against oxygen glucose deprivation and hydrogen peroxide‐induced toxicity
Authors: Rajapakse Nishadi , Kis Bela , Horiguchi Takashi , Snipes James , Busija David
Published: October 2004

Recent studies suggest that activation of mitochondrial ATP‐sensitive potassium channels (mKATP) with diazoxide can protect neurons against ischemic stress. However, it is not yet known whether astrocytes, which are more resilient against ischemia, respond similarly to diazoxide. We exposed cultured astrocytes to oxygen‐glucose deprivation (OGD) or hydrogen peroxide (H2O2) with or without pretreatment with the mKATP opener diazoxide. Marked decreases in astrocyte viability were evident after 9 and 12 hr of OGD [76% ± 3% (n = 50) and 60% ± 1% (n = 50)] and 400 and 600 μM H2O2 [40% ± 2% (n = 16) and 25% ± 2% (n = 16)], respectively, compared with no treatment (100% ± 1%). Diazoxide treatment (3 days of sequential application) dramatically reversed the negative effects of OGD and H2O2, resulting in complete blockade of astrocyte cell death. Effects of diazoxide were blocked by the mKATP blocker 5‐hydroxydecanoic acid (5‐HD). Furthermore, incubation of astrocytes with diazoxide resulted in loss of mitochondrial membrane potential monitored by tetramethylrhodamineethylester fluorescence. Additionally, generation of reactive oxygen species was observed in response to diazoxide, assessed using the oxidation‐sensitive dye hydroethidine, and this effect was abolished by antioxidants, catalase, and a superoxide dismutase mimetic, M40401. Finally, diazoxide increased the protein level of phosphorylated protein kinase C (PKC) revealed by immunoblot analysis. Our findings demonstrate that opening of mKATP by diazoxide identifies a delayed preconditioning effect that is protective against two types of injury in astrocytes and that diazoxide may deliver protection via mitochondrial depolarization, free radical production, and PKC activation. © 2003 Wiley‐Liss, Inc.
Cell‐specific expression pattern of monocarboxylate transporters in astrocytes and neurons observed in different mouse brain cortical cell cultures
Authors: Debernardi Ruth , Pierre Karin , Lengacher Sylvain , Magistretti Pierre J. , Pellerin Luc
Published: October 2004

Evidence suggests that lactate could be a preferential energy substrate transferred from astrocytes to neurons. Such a process implies the presence of specific monocarboxylate transporters on both cell types. Expression of MCT1 and MCT2, two isoforms of the monocarboxylate transporter (MCT) family, was studied in enriched cultures of mouse cortical astrocytes or neurons. It was observed that, at both the mRNA and the protein levels, astrocytes strongly expressed MCT1 but had very little if any MCT2. By contrast, neurons had high amounts of MCT2 mRNA, although MCT1 mRNA was also detected. Double immunofluorescent labelings with appropriate markers confirmed the cell‐specific preference in the expression of MCT1 and MCT2, but they revealed that a subset of neurons expresses low to moderate levels of MCT1. Parallel immunocytochemical stainings of cultured neurons with the presynaptic marker synaptophysin showed that MCT2 expression is correlated with synaptic development. Although MCT2 and synaptophysin were not colocalized, their distribution was similar, and they were often closely apposed, suggesting that MCT2 could be associated with postsynaptic terminals. Interaction between astrocytes and neurons, as occurring in layered cultures, did not modify the levels of MCT1 and MCT2 expression or their distribution and cell‐specific preference under the conditions used. However, a close apposition between neurites and MCT1‐expressing astrocytic processes was apparent and developed as cultures evolved. In addition to providing an extensive description of MCT distribution in cultured cells, our data underscore the potential of such preparations for future studies on the regulation of MCT expression. © 2003 Wiley‐Liss, Inc.
Preparation of Carboxyl‐Functionalized Polystyrene/Silica Composite Nanoparticles
Authors: Zeng Zhong , Yu Jian , Guo Zhao‐Xia
Published: October 2004

Summary: This paper describes the synthesis of carboxyl‐functionalized polystyrene/silica (PS/SiO2) composite nanoparticles with various contents of poly(methacrylic acid) (PMAA) on the surface by post‐addition of methacrylic acid (MAA) via emulsion polymerization. High yields and binding efficiencies (around 90%) are achieved by an optimal procedure mainly involving the appropriate addition of MAA and amounts of surfactant and silica. The kinetics investigated indicates that the polymerization follows a mechanism different than that found in some earlier studies. The amount of grafted PMAA was determined by titration and FT‐IR, and altered in a wide range (1–40 wt.‐% to PS). Transmission electron microscopy (TEM) photographs show that the composite nanoparticles are about 60 nm in spherical shape and have a multi‐layered core‐shell structure with a cluster of primary silica beads as the core and PMAA as the outmost shell. There are approximately 4 to 21 primary silica beads in one composite nanoparticle, depending on the amount of silica added.

Preparation of carboxyl‐functionalized polystyrene(PS)/silica composite nanoparticles.

magnified image

Preparation of carboxyl‐functionalized polystyrene(PS)/silica composite nanoparticles.
Untersuchung tribologischer Schichtsysteme mit dem Spiraltribometer
Authors: Bethke R. , Bewilogua K.
Published: October 2004

Messungen mit einer Kugel‐Scheibe‐Anordnung im Spiralmode liefern zusätzliche Informationen zum tribologischen Verhalten von Reibpaarungen, da sich die Ausbildung von Transferschichten bzw. Ablagerungen durch adhäsiven Verschleiß anders darstellt als in Testversuchen im Kreismode. Damit ist insbesondere die Möglichkeit gegeben, die tribologische Situation offener Tribosysteme besser darzustellen und messtechnisch zu erfassen. Sowohl im Spiral‐ als auch im Kreismode wurden Reibkoeffizienten verschiedener Reibpaarungen ermittelt, wobei mindestens ein Reibpartner beschichtet war. Die getesteten Schichtmaterialien waren diamantähnlicher Kohlenstoff (DLC/a‐C:H), Wolfram(W)‐haltiges DLC (W‐DLC/a‐C:H:W) und Chromnitrid (CrN). Nachfolgend werden für die beiden DLC‐basierten Schichtmaterialien nur noch die heute üblichen Bezeichnungen a‐C:H und a‐C:H:W verwendet.
Tribologische Versuche an modifizierten Gewindefurchern
Authors: Schäfer M. , Tikal F.
Published: October 2004

Gewindefurchen als umformendes Gewindefertigungsverfahren bietet gegenüber der spanenden Innengewindeherstellung wirtschaftliche und technologische Vorteile, wie z. B. keine Spanentsorgung und höhere Festigkeit der Gewindeflanken. Um das Gewindefurchen nicht nur als Gesamtumformprozess betrachten zu können, wurde ein Verfahren entwickelt, das es ermöglicht, die gleichzeitig ablaufenden Umformprozesse am Werkzeug getrennt voneinander zu betrachten. Durch die Modifizierung herkömmlicher Gewindefurcher kann jede Umformstufe separat gefertigt und die dabei auftretenden Kräfte und mechanischen Belastungen ermittelt werden. Da die Reibungszahl μ immer vom jeweiligen Bearbeitungsverfahren und Prozessparametern abhängig ist, kann sie nur experimentell ermittelt werden. Dies ist mit Hilfe des entwickelten Verfahrens am realen Formkeil möglich und wird für verschiedene Prozessparameter, wie z. B. die Werkzeugbeschichtung, Werkstückumfangsgeschwindigkeit und Werkstücktemperatur, durchgeführt.
Heterotopic limb allotransplantation model to study skin rejection in the rat
Authors: Nazzal Jamal A. , Johnson Timothy S. , Gordon Chad R. , Randolph Mark A. , Lee W.P. Andrew
Published: October 2004

Current rodent models for investigation of limb allotransplantation typically utilize orthotopic whole‐limb transplantation, a morbid and time‐consuming procedure. Our objective was to design a less morbid rat model to explore the immunological obstacles of limb transplantation, and particularly skin. Twenty lower hindlimbs from 10 donors were transplanted into a heterotopic subcutaneous position into 20 animals (10 isogeneic and 10 allogeneic). Each group was further subdivided to include animals with (n = 5) and without (n = 5) a skin paddle for observation of cutaneous signs of rejection. All grafts in the isogeneic group survived for 100 days, i.e., the endpoint of the study. Allogeneic transplants rejected their allografts at a mean of 12.8 days (with skin) and 20.6 days (without). Our heterotopic limb transplantation model takes less time and is less stressful to the animals, while allowing for early observation of graft skin rejection, when compared to orthotopic whole‐limb transplantation. © 2004 Wiley‐Liss, Inc. Microsurgery 24:448–453, 2004.
New experimental flap model in the rat: Free flow‐through epigastric flap
Authors: Özkan Ömer , Coşkunfirat O. Koray , Özgentaş H. Ege , Dikici M. Bahadir
Published: October 2004

This study describes a free flow‐through flap model in the rat for use in the evaluation of the physiologic and hemodynamic characteristics of this type of flap in clinical practice. The rat is a preferred animal model because it is inexpensive, readily available, and reliable. There is no free flow‐through flap model available for laboratory animals, although this model gained popularity in clinical use recently. Twenty Wistar rats weighing 200–250 g were used in our experiment. In 5 rats, the vascular anatomy of the groin and proximal thigh region was determined by anatomic dissection. The experimental design consisted of two groups. In the experimental group (N = 5), a flow‐through epigastric skin flap was harvested based on the femoral artery, preparing both its proximal and distal stumps. The flap was transferred to the contralateral groin, and end‐to‐end vascular anastomosis was performed between a proximal and distal stump of the femoral arteries of the flap and recipient site. The proximal stump of the femoral vein of the flap was anastomosed to the femoral vein of the recipient site. The control group was divided into two subgroups. In all control group rats (N = 10), the flap was harvested in the same manner, and transferred to the contralateral groin, but standard free‐flap procedure with one artery and one vein anastomosis was performed in 5 rats (conventional free‐flap subgroup), and anastomosis was not performed between the flap and the recipient site in the remaining 5 rats (graft subgroup). Survival of the flap was evaluated on postoperative day 7 by direct observation, and microangiography was performed to delineate the vascularity of the flow‐through flap. The results showed that all flaps survived in the experimental group and the conventional free‐flap subgroup of the control group, whereas in the graft subgroup, all flaps underwent total necrosis. The authors conclude that the flow‐through epigastric flap for the rat is a simple and reliable model for future physiologic and pharmacologic studies. © 2004 Wiley‐Liss, Inc. Microsurgery 24:454–458, 2004.
Design of a high‐directivity Electromagnetic Band Gap (EBG) resonator antenna using a frequency‐selective surface (FSS) superstrate
Authors: Lee Young Ju , Yeo Junho , Mittra Raj , Park Wee Sang
Published: October 2004

In this paper, we introduce a novel design for a high‐directivity Electromagnetic Band Gap (EBG) resonator antenna that utilizes a frequency‐selective surface (FSS) superstrate. The above type of superstrate is proposed as an alternative to an EBG type of dielectric superstrate—investigated previously by the authors—to reduce its height and facilitate the fabrication process. Although FSS superstrate and the patch antenna comprise a composite resonator, we begin by investigating the FSS structure characteristics first before dealing with the combination. We vary several important parameters, such as the distance between the FSS superstrate and the ground plane of the antenna, and the dimensions of the FSS superstrate, to determine their effect on the resonant frequency and the quality factor of the unit cell of the FSS. The above study enables us to derive some guidelines for an optimum array size of the FSS superstrate that eventually leads to a maximum directivity for the FSS antenna composite, as evidenced via a comparison of the quality factors of the FSS, the unit cell, and the composite. It is demonstrated that the directivity of the antenna with an optimized array size of the FSS superstrate increases by 17.29 to 24.92 dBi for three different strip‐dipole lengths, as compared to that of the patch antenna alone (maximum 6 dBi). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 462–467, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20502
Multiband capacitively loaded magnetic dipole
Authors: Poilasne G. , Rowson S. , Desclos L.
Published: October 2004

Capacitively loaded magnetic dipoles (CLMDs) are small antennas that are easily integrated inside mobile devices for either single or multiband applications. They can be analyzed using different approaches. Treated as regular antennas, these dipoles are versatile for implementation as they offer very high efficiency and low interaction with the surrounding components. Treated as frequency filters, they can help reduce the component count or ease the specification. Finally, treated as spatial and polarization filters, they provide very powerful solutions for diversity implementation. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 475–478, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20506
Simultaneous independent temperature and strain measurement using one fiber Bragg grating based on the etching technique
Authors: Xiaohong Li , Dexiang Wang , Fujun Zhao , Enguang Dai
Published: October 2004

A new method for the simultaneous and independent measurement of temperature and strain that employs only one FBG based upon the etching technique is demonstrated both theoretically and experimentally. The sensor using this scheme has a small sensor probe, and offers combined characteristics of compactness, effective cost, and easy fabrication. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 478–481, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20507
Gain clamping in double‐pass L‐band EDFA using a ring resonator
Authors: Harun S. W. , Samsuri N. MD , Ahmad H.
Published: October 2004

A gain‐clamped long‐wavelength‐band erbium‐doped fiber amplifier (L‐band EDFA) based on a ring‐laser cavity is demonstrated using two C/L‐band wavelength‐selective couplers. This new design provides improved gain characteristics and high tuneability. The gain is clamped at 11.5 dB with a gain variation of less than 0.1 dB from an input‐signal power of −40 to −6 dBm by setting the variable attenuation setting (VOA) at 8 dB. Also, the clamped‐gain level can be controlled to be in the range from 4.7 to 21.3 dB by varying the VOA settings from 0 to 24 dB. However, the proposed gain‐clamped amplifier suffers from noise‐figure degradation, as compared to the open‐ring amplifier, due to the intense ring‐laser light, which counter‐propagates through the EDF. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 484–486, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20509
Design of multiple U‐shaped slot microstrip patch antenna for 5‐GHz band WLANs
Authors: Ju Jeong Min , Jeong Gyey‐Teak , Yoon Joong‐Han , Ko Sung‐Won , Kwak Kyung‐Sup
Published: October 2004

In this study, a multiple U‐shaped slot microstrip patch antenna for application in the 5‐GHz band is designed and fabricated. To obtain sufficient bandwidth in the operating band, foam is inserted between the substrate and ground plane, a coaxial probe source is used, and the position of the probe shift is adjusted from the center to the left. The measured result (5.02–5.955 GHz) of the fabricated antenna satisfies the conditions of VSWR < 2.0 in 5‐GHz band (5.15–5.35 GHz, 5.47–5.725 GHz, and 5.725–5.825 GHz): gain of 3.88–9.28 dBi and broad radiation pattern. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 486–488, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20510
A practical scheme for envelope delta‐sigma modulated (EDSM) microwave power amplifier
Authors: Dupuy Alexandre , Wang Yuanxun Ethan
Published: October 2004

A delta‐sigma modulated Class‐E power amplifier is proposed and experimentally developed for high‐efficiency linear applications. The essential idea is based on the envelope delta‐sigma modulation (EDSM), which combines the Kahn technique, envelope elimination and restoration (EER), with the Delta‐Sigma modulated‐amplifier concept. The scheme increases the efficiency of the circuit by digitalizing the envelope of the signal instead of the original RF signal. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 491–495, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20512
Dynamic polarization‐dependent loss (DPDL) of planar‐waveguide‐based variable optical attenuators (VOAs)
Authors: Zhang Zhiyi , Xiao Gao Zhi , Grover Chander P.
Published: October 2004

We analyze the dynamic polarization‐dependent loss (DPDL) of planar‐waveguide‐based variable optical attenuators (VOAs). Our studies show that thermal stress is introduced in waveguides when heat is applied to achieve optical attenuation of Mach–Zehnder interferometer (MZI) coupler‐based VOAs made of silica, thus resulting in an unacceptable DPDL for such devices. The stress and its associated DPDL can be reduced significantly if two trenches are created along the waveguides. The DPDL can be further reduced to a negligible level by adopting a new VOA design based on straight waveguides and a silica–polymer hybrid structure. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 498–501, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20514
Microwave characterization of breast‐phantom materials
Authors: Bindu G. , Lonappan Anil , Thomas Vinu , Hamsakkutty V. , Aanandan C. K. , Mathew K. T.
Published: October 2004

Corn syrup and glycerine are proposed as suitable breast‐phantom materials. These materials when diluted with water in definite proportions can serve as phantoms for normal, benign, and malign breast‐tissue samples. Dielectric permittivity and conductivity studies of these materials are performed using the cavity‐perturbation technique in the frequency range of 2.4–3.2 GHz. The results are compared with the in vitro breast‐tissue data and good agreement is reported. These materials are also useful as coupling media in microwave medical imaging. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 506–508, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20517
Varactor‐tunable and dipole‐grid‐based frequency‐selective surface
Authors: Mias C.
Published: October 2004

A novel tunable frequency‐selective surface (FSS) filter configuration that can simultaneously block both vertical and horizontal polarizations is proposed. It consists of dipole elements tuned by low‐cost varactor diodes that are biased by multilayer grids. Single and series‐pair diode implementations are presented. The filter's tunable performance is demonstrated numerically and experimentally at around 2.45 GHz. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 508–511, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20518
Cross‐shaped fractal antenna: A compact circularly polarized radiating element
Authors: Abdillah M. Ben , Pascal O. , Aubert H.
Published: October 2004

A novel topology for compact circularly polarized antennas is proposed. The cross‐shaped fractal antenna (CSFA) consists of two identical prefractal dipoles that are excited with a 90° time‐phase difference between them. Such an antenna significantly reduces the space filling, compared to classical topologies, and radiates excellent circularly polarized fields over a large beamwidth. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 518–521, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20521