bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversible lymphomagenesis in conditionally c‐MYC expressing mice
Authors: Marinkovic Dragan , Marinkovic Tatjana , Mahr Bettina , Hess Jochen , Wirth Thomas
Published: April 2004

It is well documented that deregulation of MYC leads to tumor development, yet many aspects of this process are only partially understood. We have established a transgenic mouse model in which c‐MYC is conditionally expressed in lymphoid cells using the tetracycline‐regulated system of gene regulation. Mice with continuously expressed transgenic c‐MYC died of invasive T‐ or B‐cell lymphomas within 4 months. Lymphomas developing in transgenic mice were c‐MYC dependent since doxycycline treatment led to tumor regression. Using transplantation of established tumor cell lines labeled with GFP, we followed the fate of neoplastic cells in recipients upon MYC inactivation. This approach allowed us to elucidate both apoptosis and differentiation as mechanisms of tumor elimination. Comparative genomic hybridization (CGH) and FISH analyses were performed in order to analyze possible chromosomal aberrations induced by c‐MYC. We observed that overexpression of c‐MYC is sufficient to induce recurrent patterns of genomic instability. The main observation was a gain of genomic material that corresponded to chromosome 15 in several T‐cell tumors, which could be identified as trisomy. © 2004 Wiley‐Liss, Inc.
Food groups and risk of prostate cancer in Italy
Authors: Bosetti Cristina , Micelotta Stefania , Dal Maso Luigino , Talamini Renato , Montella Maurizio , Negri Eva , Conti Ettore , Franceschi Silvia , La Vecchia Carlo
Published: April 2004

Although several studies have been conducted, the relation between diet and prostate cancer remains unclear. The role of a wide range of foods on the risk of prostate cancer has thus been analyzed in a case‐control study conducted in Italy between 1991 and 2002. Cases were 1,294 patients below age 75 years with incident, histologically confirmed carcinoma of the prostate; controls were 1,451 subjects below age 75 years admitted to the same hospitals as cases for a wide spectrum of acute, non‐neoplastic conditions. Multivariate odds ratios (ORs) were obtained after allowance for major potential confounding factors, including calorie intake. Among the 19 food groups considered, 4 showed some significant association with prostate cancer risk. A significant trend of increasing risk with more frequent consumption was found for milk and dairy products (OR = 1.2 for highest vs. lowest quintile, p = 0.03) as well as bread (OR = 1.4, p = 0.01), whereas inverse associations were observed for soups (OR = 0.8, p = 0.02) and cooked vegetables (OR = 0.7, p = 0.01). This uniquely large study on prostate cancer and diet in a southern European population confirms that no strong association exists between any specific foods and prostate cancer, apart from an increased risk for milk and dairy products and a possible protective effect of vegetables. © 2004 Wiley‐Liss, Inc.
The Solow model with CES technology: nonlinearities and parameter heterogeneity
Authors: Masanjala Winford H. , Papageorgiou Chris
Published: April 2004

This paper examines whether nonlinearities in the aggregate production function can explain parameter heterogeneity in the Solow growth regressions. Nonlinearities in the production technology are introduced by replacing the commonly used Cobb–Douglas (CD) aggregated production specification with the more general Constant‐Elasticity‐of‐Substitution (CES) specification. We first justify our choice of production function by showing that cross‐country regressions favour the CES over the CD technology. Then, by using an endogenous threshold methodology we show that the Solow model with CES technology is consistent with the existence of multiple regimes. Copyright © 2004 John Wiley & Sons, Ltd.
Identification of goat sperm ecto‐cyclic AMP independent protein kinase substrate localized on sperm outer surface
Authors: Maiti Arunima , Mishra K.P. , Majumder G.C.
Published: April 2004

We have demonstrated the location of a cyclic AMP independent serine/threonine protein kinase (ecto‐CIK) on the outer surface of mature goat spermatozoa. We purified and characterized the major physiological protein substrate (MPS) of ecto‐CIK. 32P‐labeled membrane proteins phosphorylated by endogenous ecto‐CIK of intact cauda‐epididymal spermatozoa was solubilized with 1% Triton X‐100 and then fractionated by following several chromatographic techniques like Sephacryl S‐300 molecular sieve chromatography, DEAE–cellulose ion‐exchange chromatography and chromatofocussing. The MPS of ecto‐CIK has been purified to apparent homogeneity and it was found to be a monomeric protein of 100 kDa. Three isoforms of MPS have been found with pI of 6.37, 6.05, and 5.14 and all these isoforms served as the specific substrate of ecto‐CIK. The ecto‐kinase has nearly 30 times greater affinity for MPS as compared to casein the most potent exogenous protein substrate. Addition of MPS (pI 5.14) antibody caused head‐to‐head sperm agglutination. The Fv/Fab fragment of anti‐MPS caused significant inhibition of sperm motility. The data show that MPS is an ecto‐protein localized on the sperm head. MPS may thus play an important role for the regulation of sperm–egg interaction. © 2004 Wiley‐Liss, Inc.
Senescence occurs with hTERT repression and limited telomere shortening in human oral keratinocytes cultured with feeder cells
Authors: Kang Mo K. , Kameta Ayako , Shin Ki‐Hyuk , Baluda Marcel A. , Park No‐Hee
Published: April 2004

We investigated the phenotypic and molecular alterations in normal human oral keratinocytes (NHOK) during in vitro replication in two different culture conditions. The cells were cultured either in chemically defined Keratinocyte Growth Medium (KGM) without feeder layers or in serum‐containing flavin‐adenine dinucleotide (FAD) medium with feeder layers. Primary NHOK underwent 22 ± 3 population doublings (PDs) in KGM and 42 ± 4 PDs in FAD medium, reflecting 52% increase in replication capacity with feeder layers. In both culture conditions, exponentially replicating NHOK demonstrated telomerase activity and expression of human telomerase reverse transcriptase (hTERT) gene. Telomerase activity and hTERT expression were rapidly diminished in senescing NHOK, which exhibited small decrease of telomere length for the remaining limited cellular replications until the complete arrest of cell division. However, telomere length in senescent NHOK was 6.7 ± 0.5 kilobase pairs (kbps), significantly longer than that (5.12 kbps) of senescent human fibroblasts. The onset of senescence was accompanied with marked induction of p16INK4A, and this occurred in both culture systems using either KGM or FAD medium. These results indicate that replicative senescence of NHOK is associated with loss of telomerase activity followed by limited telomere shortening. © 2003 Wiley‐Liss, Inc.
Intraocular gutless adenoviral‐vectored VEGF stimulates anterior segment but not retinal neovascularization
Authors: Oshima Yuji , Takahashi Kyoichi , Oshima Sachiko , Saishin Yoshitsugu , Saishin Yumiko , Silva Raquel Lima , Liang Xaoling , Reddy P. Seshidhar , Ganesh Shanthi , Brann Terrence , Liau Gene , Kaleko Michael , Connelly Sheila , Campochiaro Peter A.
Published: April 2004

Vascular endothelial growth factor (VEGF) and insulin‐like growth factor‐1 (IGF‐1) have been implicated as important stimulatory factors for retinal neovascularization. In this study, we used intraocular gene transfer with gutless adenoviral (AGV) vectors to determine the effect of increased intraocular expression of VEGF, IGF‐1, or sphingosine kinase (SPK), which produces sphingosine‐1‐phosphate, another angiogenic factor. Retinal neovascularization did not occur from intravitreous AGV‐vectored VEGF, IGF‐1, SPK, or combined VEGF and IGF‐1, except occasionally adjacent to the retinal penetration site from the injection. However, corneal and iris neovascularization occurred after 2 weeks in all eyes injected with AGV.VEGF, but not those injected with only AGV.IGF‐1 or AGV.SPK. These data suggest that the superficial capillary bed of the retina is relatively insensitive to VEGF, IGF‐1, or SPK in adult mice, except when combined with retinal trauma. However, AGV‐vectored VEGF is sufficient to consistently cause severe corneal and iris neovascularization. This provides a model for anterior segment neovascularization, which unlike previous models is relatively inexpensive and is not plagued by spontaneous regression, and therefore, may be useful for identification of new treatments. © 2004 Wiley‐Liss, Inc.
Three novel hormone‐responsive cell lines derived from primary human breast carcinomas: Functional characterization
Authors: Vázquez Stella Maris , Mladovan Alejandro , Garbovesky Carlos , Baldi Alberto , Lüthy Isabel Alicia
Published: April 2004

Human breast cancer primary cultures are useful tools for the study of several aspects of cancer biology, including the effects of chemotherapy and acute gene expression in response to different hormonal/chemotherapy treatments. The present study reports the conditions for primary culture of breast cancer samples from untreated patients and the most effective collagenization method to dissociate human samples consisting in an overnight incubation with 1 mg/ml types II or IV collagenase and further incubation in DMEM:F12 (1:1) medium supplemented with glutamine, bovine insulin, penicillin–streptomycin, HEPES, estradiol, cortisol (F), tri‐iodothyronine (T3), transferrine (TR), and 10% fetal calf serum (FCS). These conditions proved to be appropriate for both primary culture and the development of stable cell lines. Of the seven cell lines obtained, three fast growing and estrogen receptor (ER)+/progesterone receptor (PgR)+/EGF receptor (EGFR)+ have been characterized. The cells are able to grow both in soft agar and in nude mice, and express cytokeratins, all parameters characteristic of malignant epithelial cell lines. The cells also exhibit an increased proliferation rate in the presence of estradiol, progesterone, and EGF, suggesting the presence of the corresponding receptors. The mRNA expression of type α‐ and β‐ER as well as EGFR, was confirmed by RT‐PCR. In conclusion, the novel cell lines described, arose from primary tumors and are sensitive to estradiol, progesterone, and EGF. This not only expands the repertoire of breast cancer cells available as potentially useful tools for examining most parameters in breast cancer “in vitro”, but also provides unique new models to explore the complex regulation by steroids as well as growth factors in such cells. © 2003 Wiley‐Liss, Inc.
Notch‐1 regulates cell death independently of differentiation in murine erythroleukemia cells through multiple apoptosis and cell cycle pathways
Authors: Jang Mei‐Shiang , Miao Haixi , Carlesso Nadia , Shelly Leslie , Zlobin Andrei , Darack Nicole , Qin Jian‐Zhong , Nickoloff Brian J. , Miele Lucio
Published: April 2004

Notch signaling is a potential therapeutic target for various solid and hematopoietic malignancies. We have recently shown that downregulation of Notch‐1 expression has significant anti‐neoplastic activity in pre‐clinical models. However, the mechanisms through which Notch modulation may affect cell fate in cancer remain poorly understood. We had previously shown that Notch‐1 prevents apoptosis and is necessary for pharmacologically induced differentiation in murine erythroleukemia (MEL) cells. We investigated the mechanisms of these effects using three experimental strategies: (1) MEL cells stably transfected with antisense Notch‐1 or constitutively active Notch‐1, (2) activation of Notch‐1 by a cell‐associated ligand, and (d3) activation of Notch‐1 by a soluble peptide ligand. We show that: (1) downregulation of Notch‐1 sensitizes MEL cells to apoptosis induced by a Ca2+ influx or anti‐neoplastic drugs; (2) Notch‐1 downregulation induces phosphorylation of c‐Jun N‐terminal kinase (JNK) while constitutive activation of Notch‐1 or prolonged exposure to a soluble Notch ligand abolishes it; (3) Notch‐1 has dose‐ and time‐dependent effects on the levels of apoptotic inhibitor Bcl‐xL and cell cycle regulators p21cip1/waf1, p27kip1, and Rb; and (4) Notch‐1 activation by a cell‐associated ligand is accompanied by rapid and transient induction of NF‐κB DNA‐binding activity. The relative effects of Notch‐1 signaling on these pathways depend on the levels of Notch‐1 expression, the mechanism of activation, and the timing of activation. The relevance of these findings to the role of Notch signaling in differentiation and cancer are discussed. © 2003 Wiley‐Liss, Inc.
Anaplastic lymphoma kinase proteins in growth control and cancer
Authors: Pulford K. , Morris S.W. , Turturro F.
Published: April 2004

The normal functions of full‐length anaplastic lymphoma kinase (ALK) remain to be completely elucidated. Although considered to be important in neural development, recent studies in Drosophila also highlight a role for ALK in gut muscle differentiation. Indeed, the Drosophila model offers a future arena for the study of ALK, its ligands and signalling cascades. The discovery of activated fusion forms of the ALK tyrosine kinase in anaplastic large cell lymphoma (ALCL) has dramatically improved our understanding of the pathogenesis of these lymphomas and enhanced the pathological diagnosis of this subtype of non‐Hodgkin's lymphoma (NHL). Likewise, the realisation that a high percentage of inflammatory myofibroblastic tumours express activated‐ALK fusion proteins has clarified the causation of these mesenchymal neoplasms and provided for their easier discrimination from other mesenchymal‐derived inflammatory myofibroblastic tumour (IMT) mimics. Recent reports of ALK expression in a range of carcinoma‐derived cell lines together with its apparent role as a receptor for PTN and MK, both of which have been implicated in tumourigenesis, raise the possibility that ALK‐mediated signalling could play a role in the development and/or progression of a number of common solid tumours. The therapeutic targeting of ALK may prove to have efficacy in the treatment of many of these neoplasms. © 2004 Wiley‐Liss, Inc.
TP53 in gastric cancer: Mutations in the L3 loop and LSH motif DNA‐binding domains of TP53 predict poor outcome
Authors: Migliavacca Manuela , Ottini Laura , Bazan Viviana , Agnese Valentina , Corsale Simona , Macaluso Marcella , Lupi Ramona , Dardanoni Gabriella , Valerio Maria Rosaria , Pantuso Gianni , Fede Gaetana Di , Tomasino Rosa Maria , Gebbia Nicola , Mariani‐Costantini Renato , Russo Antonio
Published: April 2004

The aim of this study was to clarify whether specific p53 mutations may have biological relevance in terms of disease relapse or death in gastric carcinomas (GC). Resected specimens from a consecutive series of 62 patients with GC undergoing potentially curative surgery were prospectively studied. The mutational status of exons 5–8 of the p53 gene was investigated in 62 cases using the PCR‐SSCP and sequencing. Presence of microsatellite instability (MSI) was evaluated in 56 cases by analyzing loci highly sensitive of MSI. Twenty mutations of p53 were detected in 17 of the 62 cases analyzed (27%). Ten mutations (50%) occurred in highly conserved domains. According to the p53 specific functional domains: 4/20 mutations (20%) were in the L3 loop and 3/20 (15%) in LSH motif. Eight of the 56 GC resulted MSI‐H, 5 (9%) MSI‐L, and 43 (77%) MSI stable (MSS). None of the 8 (14%) MSI‐H GC showed p53 mutations. p53 mutations were associated with intestinal histotype. Moreover, specific mutations in functional domain (L3 and LSH), together with advanced TNM stage, node involvement, depth of invasion, diffuse histotype, proved to be significantly related to quicker relapse and to shorter overall survival. Specific mutations in p53 functional domains, rather than any mutations in this gene, may be biologically more significant in terms of patients outcome, indicating that these mutations might have biological relevance to identify subgroups of patients at higher risk of relapse or death who might benefit from a more aggressive therapeutic approach. © 2004 Wiley‐Liss, Inc.
Apoptosis induced by interferon‐α and antagonized by EGF is regulated by caspase‐3‐mediated cleavage of gelsolin in human epidermoid cancer cells
Authors: Boccellino M. , Giuberti G. , Quagliuolo L. , Marra M. , D'Alessandro A.M. , Fujita H. , Giovane A. , Abbruzzese Alberto , Caraglia Michele
Published: April 2004

We have previously reported that interferon‐α (IFNα) induces apoptosis and EGF can antagonize this effect in human epidermoid cancer KB cells. Since apoptosis occurs together with cytoskeleton reorganization we have evaluated if IFNα and EGF could modulate cell remodeling in our experimental conditions. We have found that 48 h 1,000 IU/ml IFNα induced structural reorganization of stress fibers and membrane delocalization and partial capping of the actin severing protein gelsolin. The transfection of KB cells with both a wild type (WT) or a C‐terminal truncated form of gelsolin caused overexpression of the protein and an increase of both the spontaneous and IFNα‐induced apoptosis and cell cytoskeletal modifications. In fact, after 48 h of treatment IFNα induced 45% of apoptotic cell death in parental cells while an approximately 80% of cell population was apoptotic in transfected cells. These effects occurred together with an increase of the expression and consequent degradation of gelsolin. Again the addition of EGF to IFNα‐treated transfected cells caused a recovery of the apoptosis. Notably, IFNα and EGF did not modify the expression of other molecules associated to cytoskeleton such as focal adhesion kinase and vinculin. In the same experimental conditions IFNα induced also gelsolin cleavage that occurred together with caspase‐3 activation and release of cytochrome c. All these effects were antagonized by the exposure of IFNα‐treated KB to 10 nM EGF for the last 12 h. Moreover, the specific inhibition of caspase‐3 with 20 μM DEVD completely abrogated apoptosis and gelsolin cleavage induced by IFNα. In conclusion, our data are the first demonstration that IFNα can induce morphological cell changes that are peculiar of apoptosis onset through the caspase‐3‐mediated cleavage of gelsolin. Furthermore, we have demonstrated that EGF is able to antagonize these effects through the inhibition of caspase‐3 activation. J. Cell. Physiol. 201: 71–83, 2004. © 2004 Wiley‐Liss, Inc.
Judicious partitions of bounded‐degree graphs
Authors: Bollobás B. , Scott A. D.
Published: April 2004

We prove results on partitioning graphs G with bounded maximum degree. In particular, we provide optimal bounds for bipartitions V(G) = V1 ∪ V2 in which we minimize {e(V1), e(V2)}. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 131–143, 2004
JAB1 enhances HAND2 transcriptional activity by regulating HAND2 DNA binding
Authors: Dai Yan‐Shan , Hao Jianming , Bonin Christopher , Morikawa Yuka , Cserjesi Peter
Published: April 2004

HAND2 (also known as dHAND) is a basic helix‐loop‐helix (bHLH) transcription factor essential for development of the heart, limbs, and neural crest‐derived lineages. HAND2 expression is observed in a number of tissues derived from the neural crest, including components of the peripheral nervous system, where it has been shown to regulate sympathetic nervous system development. Here we show that HAND2 is expressed in both the sympathetic and the parasympathetic divisions of the autonomic nervous system (ANS). How HAND2 functions during development of these neuronal lineages is uncertain. An important mechanism involved in HAND2's function is its interactions with other proteins. To understand better the molecular interactions regulating HAND2 during ANS development, we employed a yeast two‐hybrid screen to identify HAND2‐interacting proteins. One protein identified in this screen, Jun activation domain‐binding protein (JAB1), is involved in numerous cell processes, including regulation of transcription and protein turnover. We show that JAB1 binds directly to the HLH domain of HAND2 and increases HAND2 transcription‐stimulating activity. However, JAB1 does not contain a transcriptional activation domain, nor does it recruit an activation domain to HAND2. Our data indicate that JAB1 augments HAND2 transcriptional activity by enhancing HAND2 DNA binding. We further show that enhanced HAND2 DNA binding is mediated through the HLH domain and not through the DNA binding domain. These results show that JAB1 regulates the transcriptional activity of HAND2 in a unique manner that may account, in part, for the apparent ability of this bHLH factor to regulate gene expression through numerous mechanisms. © 2004 Wiley‐Liss, Inc.
Computer‐identified nuclear localization signal in exon 1A of the transporter DMT1 is essentially ineffective in nuclear targeting
Authors: Kuo H.C. , Smith J.J. , Lis A. , Zhao L. , Gonsiorek E.A. , Zhou X. , Higgins D.M. , Roth J.A. , Garrick M.D. , Garrick L.M.
Published: April 2004

Divalent metal transporter 1 (DMT1; also called DCT1, Nramp2, or SLC11A2) has multiple isoforms that localize differently in many cell types. DMT1 +IRE species (encoded by mRNA with an iron‐responsive element) are limited to the plasma membrane and cytosolic vesicles. In neural cells, –IRE isoforms of DMT1 (encoded by mRNA lacking an IRE) localize to the nucleus, plasma membrane, and cytosolic vesicles. In considering nuclear compartmentalization of –IRE isoforms, we hypothesized that the newly identified exon 1A in the N‐terminus of this transporter might contain a nuclear localization signal. DNA constructs starting with exon 1A and ending with exons encoding alternative isoforms were made and transiently transfected into HEK293T and PC12 cells as well as rat sympathetic neurons. None of the constructs appeared in the nucleus despite the presence of exon 1A. Antibody specific for exon 1A was also used in both immunostaining and Western blots to investigate localization of exon 1A expressed both endogenously and ectopically in cells. Again, nuclear localization of DMT1 containing exon 1A was not observed. Our data suggest that exon 1A is neither sufficient nor necessary for DMT1 to appear in the nucleus. © 2004 Wiley‐Liss, Inc.
Determination of the purity of ampicillin by micellar electrokinetic chromatography and reversed phase liquid chromatography on a monolithic silica column
Authors: Doležalová Milada , Kunteová Bohdana , Jobánek Roman
Published: April 2004

A micellar electrokinetic chromatographic (MEKC) method and a fast reversed‐phase liquid chromatographic one have been developed for determining the purity of ampicillin. MEKC separation of ampicillin and its related substances was performed with the use of an untreated fused‐silica capillary and 40 mM phosphate‐borate buffer, pH 7.5 containing 75 mM SDS. The HPLC method employed a monolithic silica C18 column and a mobile phase composed of phosphate buffer, pH 5.2 and ACN, the flow rate being 4.0 mL/min. Both methods were successfully validated. Linearity, relative response factors, limits of quantitation, intermediate precision, and accuracy were evaluated. The methods proved to be fast, reliable, and sufficiently sensitive and, accordingly, well‐suited for control of purity of ampicillin substance, injections, and capsules. A combination of both methods can be very useful in the confirmation of impurity profiles.
Vinyl‐Type Polymerization of Norbornene Dicarboxylic Acid Dialkyl Esters
Authors: Shin Boo‐Gyo , Jang Myoung‐Souk , Yoon Do Yeung , Heitz Walter
Published: April 2004

Summary: Poly(cis‐norbornene‐exo‐2,3‐dicarboxylic acid dialkyl esters) (alkyl = Me, Et, Pr, Bu, Pen, and Hex) are synthesized as a vinyl‐type with a palladium(II) catalyst in high yield from easily prepared, pure exo‐monomers. The polymers show good solubility in common organic solvents and excellent thermal stability up to 330 °C. The polymers with alkyl groups larger than methyl exhibit a two‐step thermal degradation profile of an initial thermal degradation of side‐chains starting at 350 °C, followed by thermal degradation of the norbornene backbone starting at ca. 430 °C. The glass transition temperature decreases and the mechanical flexibility increases as the alkyl length of the side‐chain increases.

Normalized loss shear modulus (G″) versus temperature for polynorbornene dicarboxylic acid dialkyl esters.

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Normalized loss shear modulus (G″) versus temperature for polynorbornene dicarboxylic acid dialkyl esters.
Use of Transmission Electron Microscopy in Combinatorial Studies of Functional Oxides
Authors: Bendersky Leonid A. , Takeuchi Ichiro
Published: April 2004

Summary: The principles of combinatorial methodology are based on high‐throughput properties measurements (HTPM) of multiple compositions in combinatorial libraries, and are recently being increasingly applied in materials research. Nevertheless, the authors' view is that the involvement of detailed but time‐consuming investigation using transmission electron microscopy (TEM) should be an important part of combinatorial materials research. In this paper we present three examples from our combinatorial studies where the TEM investigation was essential in obtaining a detailed picture of microstructures and their relationship with the physical properties. In the study of microwave dielectrics such as BaTiO3‐SrTiO3, TEM provides essential information on the type and distribution of defects in the deposited films. In the case of the wide‐band semiconductor ZnO‐MgO, the distribution and morphology of the phases were studied and related to the measured electronic properties. Study of the manganates LaMnO3‐CaMnO3 with colossal magneto‐resistive properties showed an anisotropic distribution of the structural domains and the morphology of the film. The distribution of the domains and the absence of epitaxial stresses found are essential in the interpretation of magnetic measurements.

Cross‐sectional TEM (dark field) micrograph taken with the reflection of h‐(Zn,Mg)O at x = 0.5.

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Cross‐sectional TEM (dark field) micrograph taken with the reflection of h‐(Zn,Mg)O at x = 0.5.
The Formation of Biodegradable Polymeric Micelles from Newly Synthesized Poly(aspartic acid)‐block‐Polylactide AB‐Type Diblock Copolymers
Authors: Arimura Hidetoshi , Ohya Yuichi , Ouchi Tatsuro
Published: April 2004

Summary: A poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymer was synthesized through the polymerization of β‐benzyl‐L‐aspartate‐N‐carboxyanhydride [Asp(OBzl)‐NCA] with amino‐terminating polylactide (NH2‐PLA) as a macroinitiator. The chain length of the PAsp segment could be easily controlled by changing the monomer/initiator ratio. Dynamic light scattering measurements of PAsp‐block‐PLA aqueous solutions revealed the formation of polymeric micelles. Changes in the micelles as a function of pH were investigated.

The structure and formation of micelles of the poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymers synthesized here.

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The structure and formation of micelles of the poly(aspartic acid)‐block‐polylactide (PAsp‐block‐PLA) diblock copolymers synthesized here.
Polymeric Photoinitiator Containing In‐Chain Thioxanthone and Coinitiator Amines
Authors: Jiang Xuesong , Yin Jie
Published: April 2004

Summary: A polymeric photoinitiator (PTXP) containing in‐chain thioxanthone (TX) and coinitiator amines was synthesized by step‐growth polymerization, as well as low‐molecular‐weight model compounds. Photopolymerizations of methyl methacrylate (MMA) initiated by these photoinitiator systems were studied. Compared with corresponding low‐molecular‐weight model compounds, PTXP has a similar UV‐vis spectrum with a red‐shifted maximum absorption, and weaker fluorescence emission, and can photoinitiate the polymerization of MMA more effectively.

The structure of PTXP, the photoinitiator synthesized here.

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The structure of PTXP, the photoinitiator synthesized here.
Morphology and Crystallization Behavior of Poly(butylene succinate)‐Based Ionomers (PBSi)
Authors: Han Sang‐Il , Lee Wan Duk , Kim Dong Kook , Im Seung Soon
Published: April 2004

Summary: The crystallization behavior of a poly(butylene succinate)‐based ionomer (PBSi) was analyzed by morphological observations and synchrotron small‐angle X‐ray scattering (SAXS) experiments. The spherulitic morphology of PBSi is composed of irregular lamellae propagating outwards from the center with ionic clusters isolated from the crystalline lamellae. Synchrotron radiation SAXS profiles revealed that the re‐crystallization during heating process was effectively retarded with increasing ionic content, suggesting that the presence of ion aggregates affects the extent of diffusion of chains towards crystallization.

PBSi‐3 was isothermally crystallized at 85 °C for 30 min (400×). The spherulites of PBSi‐3 showed an irregular ringed pattern without a distinct center of spherulite.

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PBSi‐3 was isothermally crystallized at 85 °C for 30 min (400×). The spherulites of PBSi‐3 showed an irregular ringed pattern without a distinct center of spherulite.
Isoconversional Approach to Evaluating the Hoffman–Lauritzen Parameters (U* and Kg) from the Overall Rates of Nonisothermal Crystallization
Authors: Vyazovkin Sergey , Sbirrazzuoli Nicolas
Published: April 2004

Summary: An equation has been derived that correlates the temperature coefficient of the growth rate with the temperature dependence of the effective activation energy of the overall crystallization rate, which can be measured by differential scanning calorimetry. The dependence is evaluated by using an advanced isoconversional method and is parameterized in terms of the Hoffman–Lauritzen equation. The parameters obtained for the nonisothermal crystallization of the poly(ethylene terephthalate) melt are consistent with the parameters reported for isothermal crystallization.

The fit of the equation derived here is shown for data corresponding to the dependence of the effective activation energy on average temperature (fit = solid line).

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The fit of the equation derived here is shown for data corresponding to the dependence of the effective activation energy on average temperature (fit = solid line).
Striatal microinfusion of Tourette syndrome and PANDAS sera: Failure to induce behavioral changes
Authors: Loiselle Christopher R. , Lee Olivia , Moran Timothy H. , Singer Harvey S.
Published: April 2004

Rodent striatal microinfusions have been suggested as a model for assessing the behavioral effects induced by antineuronal antibodies. We used this approach to evaluate the proposed autoimmune etiology for Tourette syndrome (TS) and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS). Sera were assessed from patients with TS (n = 9) preselected based on the presence of elevated enzyme‐linked immunosorbent assay optical densities against putamen homogenate and sera from patients with PANDAS (n = 8), selected from a larger group assayed for antibodies against a putamen synaptosomal preparation. The effect of antibodies against the streptococcal M5 protein were also studied. A total of 44 Fischer rats received bilateral infusion of sera: 23 ventral striatum (5 PANDAS, 5 TS, 5 anti‐M5 protein, and 8 control); 21 ventrolateral striatum (5 PANDAS, 5 TS, 5 anti‐M5 protein, and 6 controls). Cannulas were placed bilaterally and symmetrically by stereotactic techniques. After animals were allowed to recover for 1 week, sera were microinfused for 3 days. Animal behavior was then simultaneously quantified by daily observation and monitoring using automated activity boxes for 10 days after infusion. No significant alterations in stereotypic behavior or movement were observed between the PANDAS, TS, or anti‐M5 protein and control groups. Our findings are in contrast to previous reports, and suggest the need for further investigations to determine the validity of the model and of autoimmune‐mediated hypotheses for pediatric movement disorders. © 2003 Movement Disorder Society
Static balance impairment and its change after pallidotomy in Parkinson's disease
Authors: Hagiwara Naoki , Hashimoto Takao , Ikeda Shu‐Ichi
Published: April 2004

We compared postural sway parameters during a 1‐minute quiet stance in 28 patients with idiopathic Parkinson's disease (PD) in off phase with those in 17 age‐matched normal subjects and investigated differences in the sway parameters before and after unilateral pallidotomy in 16 PD patients. The PD patients showed larger sway area (SA) and longer total sway path length (SPL) compared with normal subjects. Total SPL after subtraction of tremor effect did not differ from that in normal subjects. The shift of the mean center of foot pressure (CFP) position from the first 30 seconds to the last 30 seconds showed that the CFP tended to move forward in PD patients compared with normal subjects and to move laterally more in PD patients than normal subjects, especially in those with less severity (Unified Parkinson's Disease Rating Scale, motor score < 40). After the operation, there was little change in either SA or lateral movement of CFP, but forward movement of CFP and total SPL tended to be normalized, along with an improvement of major parkinsonian symptoms. From these results, it is concluded that SPL elongation significantly involves tremor effect, forward movement of CFP in PD derives from basal ganglia dysfunction, and SA enlargement and large lateral movement of CFP may be caused partly by compensatory movements or by dysfunction outside the basal ganglia circuitry. © 2003 Movement Disorder Society
Marked asymmetry of putaminal pathology in an MSA‐P patient with Pisa syndrome
Authors: Hozumi I. , Piao Y.S. , Inuzuka T. , Matsuyama Z. , Yamada Y. , Hara A. , Hirose T. , Tsuchiya K. , Takahashi H.
Published: April 2004

We report on an autopsy case of a 62‐year‐old Japanese woman with a 2.5‐year history of axial dystonia. She presented with a form of axial dystonia reminiscent of Pisa syndrome. The pathophysiological mechanism underlying forms of axial dystonia remains to be elucidated. We report here the histopathological findings of a multiple system atrophy of parkinsonian predominance (MSA‐P) patient with Pisa syndrome. © 2003 Movement Disorder Society
Adult nonketotic hyperglycinemia (NKH) crisis presenting as severe chorea and encephalopathy
Authors: Hall Deborah A. , Ringel Steven P.
Published: April 2004

We report on a patient with mild episodic nonketotic hyperglycinemia (NKH) on valproate who developed episodes of encephalopathy and chorea provoked by a fever and protein loading. After treatment with sodium benzoate and dextromethorphan, the patient's encephalopathy resolved and her chorea improved. The importance of this case is in recognizing this rare syndrome, which may present in the adult population. © 2003 Movement Disorder Society
Zydis selegiline reduces off time in Parkinson's disease patients with motor fluctuations: A 3‐month, randomized, placebo‐controlled study
Authors: Waters Cheryl H. , Sethi Kapil D. , Hauser Robert A. , Molho Eric , Bertoni John M.
Published: April 2004

Zydis selegiline dissolves on contact with saliva and undergoes pregastric absorption. This minimizes first‐pass metabolism and provides high plasma concentrations of selegiline. In this study, the efficacy and safety of Zydis selegiline was assessed in Parkinson's disease (PD) patients who were experiencing motor fluctuations with levodopa. Patients were randomly assigned to either drug or placebo in a 2:1 ratio in this double‐blind, multicenter trial. Significant reductions in daily off time occurred at 4 to 6 weeks with the 1.25 mg dose (9.9%, P = 0.003) and 10 to 12 weeks with the 2.5 mg dose (13.2%, P < 0.001). The total number of off hours was reduced by 2.2 hours at Week 12 from baseline (compared with 0.6 hours in the placebo group). The average number of dyskinesia‐free on hours for the Zydis selegiline patients increased by 1.8 hours at Week 12. There was no change in mean percentage of “Asleep” time throughout the study. No apparent differences were detected in the occurrence of drug‐related adverse events between the Zydis selegiline group and placebo‐treated groups. Adverse events were consistent with known effects of levodopa therapy. Zydis selegiline safely reduces daily off time when used as adjunctive therapy with levodopa in patients with PD. © 2004 Movement Disorder Society
A matrix inversion technique for the spherical modal decomposition field solution applied on the characterization of antennas in their environment
Authors: Mekki‐Kaidi M. , Lautru D. , Bancet F. , Fouad Hanna V.
Published: April 2004

An efficient matrix‐inversion technique is proposed for the spherical modal decomposition (SMD) field solution for radiating structures. The advantages of this approach compared to the classical dot‐product technique are demonstrated through its application to the characterization of two radiating structures: the Yagi antenna and an antenna on the roof of a vehicle. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 336–341, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20134
A slot‐shaped dielectric‐filled waveguide antenna for beam‐scanning
Authors: Chainon S. , Himdi M.
Published: April 2004

This paper presents a new geometry based on a slot‐shaped waveguide antenna for beam‐scanning applications. The slot is L‐shaped and composed of centered and transversal longitudinal parts. The longitudinal slot is the radiated part whereas the transversal part is the feeder. By properly adjusting the transversal part's position, beam scanning can be achieved, especially in 45° increments, which can be interesting for active antennas. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 341–343, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20135
A SiGe micromixer for 2.4/5.2/5.7‐GHz multiband WLAN applications
Authors: Wang C. Y. , Lu S. S. , Meng C. C. , Lin Y. S.
Published: April 2004

A SiGe micromixer for 2.4/5.2/5.7‐GHz multiband WLAN applications is demonstrated for the first time. Our experimental results show that the input return loss |S11| is below −18 dB from DC to 20 GHz with voltage gains of 32, 26, and 25 dB at frequencies of 2.4, 5.2, and 5.7 GHz, respectively. The wideband matching characteristic makes the micromixer very suitable for multiband applications. Input P1dB= −14 dBm and IIP3= −6 dBm. Port‐to‐port isolation is also quite satisfactory. In addition, the single‐to‐differential input stage in the Gilbert micromixer eliminates the need for common‐mode rejection. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 343–346, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20136
A WATT‐level 2.3‐GHz GaAs MESFET power amplifier with gap‐coupled microstrip‐line matching topology
Authors: Meng C. C. , Wang W.
Published: April 2004

A one‐stage hybrid power amplifier integrated with gap‐coupled microstrip lines for impedance matching is demonstrated in this work. The gap‐coupled microstrip line amplifier module realized here can provide 15‐dB power gain, 33.5‐dBm output power, and 42% power‐added efficiency (PAE) at 2.3 GHz. The demonstrated topology is suitable in monolithic IC technology, especially in the millimeter‐wave frequency because the gap‐coupled microstrip lines can be easily compacted into small size. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 346–348, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20137
An active broadband‐transmitting patch antenna for GSM‐1800 and UMTS
Authors: Segovia‐Vargas D. , González‐Posadas V. , Vázquez J. L. , Rajo E. , Inclán L. , Martin C.
Published: April 2004

This paper presents an active broadband‐transmitting patch antenna, which works in the 1650–2300‐MHz band to provide GSM‐1800 and UMTS services. An increase of the reflection bandwidth of the referenced passive antenna has been achieved due to the resistively equalized broadband‐amplifying active antenna. An increase in equivalent isotropic radiated power (EIRP) of 11–12 dB compared to the passive antenna, with a ripple lower than ±0.5 dB, has also been achieved. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 350–354, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20139
Photonic‐microwave harmonic mixers based on electroabsorption modulators
Authors: Polo V. , Gomez G. , Martinez A. , Herrera J. , Marti J.
Published: April 2004

Two harmonic photonic‐downconversion schemes employing electroabsorption modulators are proposed and experimentally demonstrated. Harmonic downconversion of 34‐Mb/s data modulated onto a 9.5‐GHz signal has been performed using (i) a single electroabsorption modulator, (ii) a Mach–Zehnder modulator and an electroabsorption modulator in series. Error‐free operation for both schemes is demonstrated after transmission of the IF signal through a 25‐km fiber‐optic link for harmonic orders of up to three. The influence of the biasing point of the modulator on the overall performance of both photonic downconversion schemes is discussed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 361–364, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20141
The attenuation and slow‐wave characteristics of an inverted embedded (IEM) metal‐insulator semiconductor (MIS) microstrip line
Authors: Yin W. Y. , Dong X. T.
Published: April 2004

The attenuation and slow‐wave characteristics in an inverted embedded metal‐insulator‐semiconductor (IEM‐MIS) microstrip line are investigated in this paper, based on the extracted frequency‐dependent distributed parameters, that is, per‐unit‐length series resistance and inductance, shunt capacitance, and conductance of the structure. Parametric studies are performed to show the combined effects of different parameters, such as strip thickness, width, conductivity, embedding depth, and silicon conductivity and its thickness, on the mode attenuation constant and slow‐wave factor (SWF). © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 366–369, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20143
Input impedance of electromagnetic bandgap resonator antennas
Authors: Sauleau Ronan , Coquet Philippe
Published: April 2004

The input impedance of directive electromagnetic bandgap (EBG) resonator antennas is studied theoretically and experimentally at millimeter‐wave frequencies. These antennas consist of a printed primary source illuminating a metallo‐dielectric EBG radome through a free‐space coupling region. A Fabry–Perot (FP)‐type resonator with highly reflecting metallic strip gratings is used. The variations of input impedance, resonant frequency, and return loss at resonance are investigated as functions of the thickness of the coupling region, for various topologies of (i) printed sources (single‐ and double‐layer patch antennas and arrays) and (ii) EBG cavities with a variable Q factor (that is, directivity). We also demonstrate that the coupling conditions are optimized when the resonator is fed by a relatively directive primary source (here, a 2 × 2 aperture‐coupled patch‐antenna array), rather than by a patch or a wire antenna, as is usually done. In that case, the required accuracy of the coupling region's thickness is much less stringent, which is essential from a practical point of view. These theoretical results are experimentally validated at 60 GHz through the characterization of several configurations of EBG antennas. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 369–375, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20144
Fractal Yagi antennas: Design, simulation, and fabrication
Authors: Gianvittorio John P. , Rahmat‐Samii Yahya
Published: April 2004

Multiband elements based on the self‐similarity of fractals may have differing radiation patterns between operating bands due to the leakage of current between scales in the geometry. A multiband Sierpinski element has been designed using embedded filters to achieve similar radiation patterns over various operating bands. This multiband element is incorporated into the design of a dual‐band Yagi antenna. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 375–380, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20145
A novel tunable fiber‐optic microwave notch filter using fiber loop and cascaded fiber Bragg gratings
Authors: Chi Hao , Zhang Xianmin
Published: April 2004

We experimentally demonstrate a novel tunable microwave notch filter using a fiber loop and cascaded fiber Bragg gratings (FBGs), where the filter response can be easily tuned by adjusting the wavelength of the input light. The proposed notch filter is very simple to realize. The required free spectral range (FSR) of the filter can be designed by carefully controlling the written positions of the FBGs in the fiber loop. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 386–388, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20147
Analysis of rectangular‐groove waveguides using the Fourier‐transform technique
Authors: Jia Hongting , Yasumoto Kiyotoshi , Yoshitomi Kuniaki
Published: April 2004

A rigorous and simple method for analyzing a rectangular‐groove guide using a Fourier‐transform technique, which takes the field singularities at the edge of the guide into consideration, is presented. The convergence of the solutions is very fast and the accuracy improves significantly. It is shown that a mode‐propagation constant with five‐figure accuracy is obtained by solving a 7 × 7 matrix equation. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 388–392, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20148
Effect of variation of dielectric constant of substrate on PBG in microwave region
Authors: Tiwari Manoj K. , Gupta K. K. , Gupta H. C. , Dube D. C.
Published: April 2004

The effects of variation of the substrate's dielectric constant and of various geometries on photonic band gap (PBG) are studied on a microstrip‐type periodic metallic structure, and the experimental findings are presented and discussed. In this study, air is chosen as the dielectric material of the substrate. A well‐defined PBG has been observed in all the above cases. The band‐gap changes in the microwave region with the variation of the substrate's dielectric constant and the geometry of the periodic metallic structure are due to characteristic impedance. The transmission loss has been found to decrease with an increase in the dielectric constant of the substrate. Thus, it is concluded that the dielectric constant combined with the characteristic impedance of the periodic structure plays an important role in the formation of PBG. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 399–403, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20152
Analytically regularized evaluation of scattering by perfectly conducting cylinders
Authors: Lucido M. , Panariello G. , Schettino F.
Published: April 2004

The aim of this paper is to analyze the scattering by a rectangular‐section perfectly conducting cylinder. The solution method is based on the use of the Neumann series; the problem is regularized by factorizing the right edge behavior of the current. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 410–414, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20155
Load matching in multimode microwave‐heating applicators based on the use of dielectric‐layer moulding with commercial materials
Authors: Monzó‐Cabrera J. , Escalante J. , Díaz‐Morcillo A. , Martínez‐González A. , Sánchez‐Hernández D.
Published: April 2004

Commercial dielectric materials placed around a sample are studied as load‐matching elements for multimode microwave‐heating applicators. The dimensions of these dielectric materials are optimized with an iterative procedure in order to achieve high‐power efficiency, thus enhancing electric‐field deposition within the sample. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 414–417, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20156