bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloning and analysis of axolotl ISL2 and LHX2 LIM‐homeodomain transcription factors
Authors: Showalter Aaron D. , Yaden Benjamin C. , Chernoff Ellen A.G. , Rhodes Simon J. 
Published: March 2004

AbstractSummary: We cloned and characterized the ISL2 and LHX2 LIM‐homeodomain transcription factors of the Mexican salamander, or axolotl, Ambystoma mexicanum. Using a degenerate PCR approach, partial cDNAs representing five LIM‐homeodomain genes were cloned, indicating conservation of this class of transcription factors in urodeles. Full‐length cDNAs for Isl2 and Lhx2 were identified and sequenced. The predicted ISL2 and LHX2 proteins are well conserved, especially in the LIM and DNA‐binding domains. The Isl2 and Lhx2 genes are expressed at all examined stages of embryogenesis and display tissue‐restricted expression patterns in adults. In functional tests, axolotl LHX2 was inactive compared to homologous mammalian factors and adopted unusual DNA/protein complexes. However, axolotl ISL2 bound and induced transcription from the rat insulin gene. These experiments demonstrate conservation of key developmental regulatory proteins in salamanders and will allow future studies of their potential roles in the molecular regulation of tissue regeneration in such species. genesis 38:110–121, 2004. © 2004 Wiley‐Liss, Inc.
Fibrillar prion peptide (106–126) and scrapie prion protein hamper phagocytosis in microglia
Authors: Ciesielski‐Treska Jaroslava , Grant Nancy J. , Ulrich Gabrielle , Corrotte Matthias , Bailly Yannick , Haeberle Anne‐Marie , Chasserot‐Golaz Sylvette , Bader Marie‐France 
Published: March 2004

AbstractThe inflammatory response in prion diseases is dominated by microglial activation. As macrophages of the central nervous system, the phagocytic capacity of microglia is well recognized, and it is possible that microglia are involved in the removal and processing of amyloid fibrils, thus preventing their harmful effect. We have analyzed the effects of a synthetic peptide of the human prion protein, PrP(106–126), which can form fibrils, and the pathogenic form of prion protein, PrPsc, on phagocytosis in microglia isolated from neonatal rat brain cultures. To some extent, fibrillar PrP(106–126) is internalized and processed. However, both synthetic prion peptide PrP(106–126) in a fibrillar form and pathogenic prion protein PrPsc severely hamper the phagocytic activity as measured by the uptake of beads by microglia. At a concentration that does not induce microglial death, PrP(106–126) reduced the number of beads internalized and altered their cytoplasmic distribution. This effect was not due to decreased binding of beads to the cell surface, nor restricted to specific classes of receptors. Although the PrP(106–126) did not prevent F‐actin and Rac1 accumulation at sites of particle engulfment, it appeared to interfere with a later step of the internalization process. © 2004 Wiley‐Liss, Inc.
Glutamine‐induced free radical production in cultured astrocytes
Authors: Jayakumar Arumugam R. , Rama Rao K.V. , Schousboe Arne , Norenberg Michael D. 
Published: March 2004

AbstractAmmonia is a neurotoxin implicated in the pathogenesis of hepatic encephalopathy, Reye's syndrome, inborn errors of the urea cycle, glutaric aciduria, and other metabolic encephalopathies. Brain ammonia is predominantly metabolized to glutamine in astrocytes by glutamine synthetase. While the synthesis of glutamine has generally been viewed as the principal means of ammonia detoxification, this presumed beneficial effect has been questioned as growing evidence suggest that some of the deleterious effects of ammonia may be mediated by glutamine rather than ammonia per se. Since ammonia is known to induce the production of free radicals in cultured astrocytes, we investigated whether such production might be mediated by glutamine. Treatment of astrocytes with glutamine (4.5 mM) increased free radical production at 2–3 min (95%;P< 0.05), as well as at 1 and 3 h (42% and 49%, respectively;P< 0.05). Similarly treated cultured neurons failed to generate free radicals. Free radical production by glutamine was blocked by the antioxidants deferoxamine (40 μM) and α‐phenyl‐N‐tert‐butyl‐nitrone (250 μM), as well as by the nitric oxide synthase inhibitor Nω‐nitro‐L‐arginine methyl ester (500 μM). Free radical production was also blocked by 6‐diazo‐5‐oxo‐L‐norleucine (1 mM), an inhibitor of glutaminase, suggesting that ammonia released by glutamine hydrolysis may be responsible for the generation of free radicals. Additionally, the mitochondrial permeability transition inhibitor, cyclosporin A, blocked free radical production by glutamine. The results indicate that astrocytes, but not neurons, generate free radicals following glutamine exposure. Glutamine‐induced oxidative and/or nitrosative stress may represent a key mechanism in ammonia neurotoxicity. © 2004 Wiley‐Liss, Inc.
Internal architecture, origin‐insertion site, and mass of jaw muscles in Old World hamsters
Authors: Satoh Kazuhiko , Iwaku Fumihiko 
Published: March 2004

AbstractThe jaw muscle (i.e., masticatory, suprahyoid, and extrinsic tongue) anatomy and mass were examined in four genera of Old World hamsters (cricetine murids), Mesocricetus, Cricetulus, Tscherskia, and Phodopus. The masseter was the largest and most complicated of the muscles examined. In the superficial layer, a few ventral fibers form a small medially turned portion with an insertion site more similar to those of sciurids than of other murids. In Mesocricetus, the superficial layer has a discrete anteroventral portion that has not been reported for other murid rodents. Examination of the fiber attachment sites indicated that the deep layer contains four parts and the medial layer contains three parts. The deep layer originates from two aponeuroses that are firmly connected to each other at their anterior ends and lie along the zygomatic arch. The aponeurosis of insertion for the deep layer is situated along the masseteric ridge and the dorsal border of the angular process, but is absent in its middle part, consistent with reports in two relatives, sigmodontine and arvicoline murids. In cricetine murids, unlike in other rodents, fibers insert on the dorsal narrow strip of the posterior mandibular aponeurosis, not on its broad medial aspect. The relative mass of some masticatory and suprahyoid muscles is related to body mass. Small species (Cricetulus and Phodopus) have relatively larger masseter and mylohyoid muscles and smaller temporalis and geniohyoid muscles than large species (Mesocricetus and Tscherskia). J. Morphol. 260:101–116, 2004. © 2004 Wiley‐Liss, Inc.
Mechanical functions of setae from the mouth apparatus of seven species of decapod crustaceans
Authors: Garm Anders 
Published: March 2004

AbstractThe mouthpart setae of seven species of decapods were examined with macro‐video recordings and scanning electron microscopy. The general mechanical (nonsensory) functions of the different mouthparts are described and an account of their setation is given. This offers the possibility to determine the mechanical functions of the different types of setae. Pappose setae do not participate in food handling but in general make setal barriers. Plumose setae likewise do not contact food objects but assist in current generation. Papposerrate setae are rare but they were seen to assist in pushing food particles into the mouth. Serrulate setae are very common and mainly participate in gentle food handling and grooming. Serrate setae are used for more rough food manipulation and grooming. The roughest shredding, tearing, and manipulation of prey items are handled by the cuspidate setae. Simple setae seem to be divided into two populations with very different functions. On the maxillipeds of Panulirus argus they are used for shredding, tearing, and holding the food objects, but on the basis of maxilla 2 of three other species they appear to have very little mechanical influence and only when handling small prey items. The functional scheme seems to be consistent within the Decapoda. J. Morphol. 260:85–100, 2004. © 2004 Wiley‐Liss, Inc.
Chemokine receptors are expressed widely by embryonic and adult neural progenitor cells
Authors: Tran Phuong B. , Ren Dongjun , Veldhouse Thomas J. , Miller Richard J. 
Published: March 2004

AbstractWe investigated the expression and functions of chemokine receptors in neural progenitor cells isolated from embryonic and adult mice. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis demonstrated mRNA expression for most known chemokine receptors in neural progenitor cells grown as neurospheres from embryonic (E17) and adult (4‐week‐old) mice. The expression of CXCR4 receptors was demonstrated further in E17 neurospheres using immunohistochemistry, in situ hybridization, Northern blot analysis and fura‐2‐based Ca2+ imaging. Most neurospheres grown from E17 mice responded to stromal cell‐derived factor‐1 (SDF‐1/CXCL12) in Ca2+ imaging studies. In addition, immunohistochemical studies demonstrated that these neurospheres consisted of dividing cells that uniformly colocalized nestin and CXCR4 receptors. Differentiation of E17 neurospheres yielded astrocytes and neurons exhibiting several different phenotypes, including expression of calbindin, calretinin, gamma‐aminobutyric acid (GABA), and glutamate, and many also coexpressed CXCR4 receptors. In addition, neurospheres grown from the subventricular zone (SVZ) of 4‐week‐old mice exhibited large increases in Ca2+ in response to CXCL12 and several other chemokines. In comparison, neurospheres prepared from olfactory bulb of adult mice exhibited only small Ca2+ responses to CXCL12, whereas neurospheres prepared from hippocampus were insensitive to CXCL12, although they did respond to other chemokines. Investigations designed to investigate whether CXCL12 can act as a chemoattractant demonstrated that cells dissociated from E17 or adult SVZ neurospheres migrated toward an CXCL12 gradient and this was blocked by the CXCR4 antagonist AMD3100. These results illustrate widespread chemokine sensitivity of embryonic and adult neural progenitor cells and support the view that chemokines may be of general importance in control of progenitor cell migration in embryonic and adult brain. © 2004 Wiley‐Liss, Inc.
Patterning of spinal cord oligodendrocyte development by dorsally derived BMP4
Authors: Miller Robert H. , Dinsio Kyl , Wang Rae , Geertman Robert , Maier Charles E. , Hall Alison K. 
Published: March 2004

AbstractOligodendrocyte precursors (OPCs) initially arise in the motor neuron domain of the ventral ventricular zone of the developing spinal cord. After dispersal throughout gray and white matter, OPCs differentiate in a characteristic ventral to dorsal sequence. The spatial localization of OPC induction is in part a result of both positive local sonic hedgehog signaling and dorsally derived inhibitory cues. One component of dorsal inhibitory signals seems to be members of the transforming growth factor β (TGFβ) superfamily such as the bone morphogenetic proteins (BMPs). We show that during the initial appearance and subsequent maturation of OPCs, BMP4 was expressed specifically in the dorsal midline and its expression was correlated spatially and temporally with phospho‐Smad 1+, BMP4‐responsive cells. Implantation of sonic hedgehog (Shh)‐coated beads adjacent to dorsal spinal cord in Xenopus embryos induced ectopic dorsal OPCs whereas BMP4‐coated beads inhibited OPC appearance. More importantly, blocking endogenous dorsal BMP4 with anti‐BMP4‐coated beads locally induced ectopic OPCs. Similar results were obtained using soluble ligands on slice preparations of rodent spinal cord in vitro. In dissociated cell cultures of embryonic rat spinal cord, Shh and BMP4 had antagonistic effects on OPC development and the sensitivity of oligodendrocyte lineage cells to BMP4 increased with maturation. These data suggest that BMP4 contributes to the pattern of spinal cord oligodendrogenesis by regulating both induction and maturation of spinal cord OPCs. © 2004 Wiley‐Liss, Inc.
Oxidative stress inhibits ionomycin‐mediated cell death in cortical neurons
Authors: McCollum Adrian T. , Jafarifar Faegheh , Chan Roy , Guttmann Rodney P. 
Published: March 2004

AbstractThiol‐proteases play important roles in many cellular processes, including maintenance of protein homeostasis and execution of cell death. Therefore, determining how this family of enzymes is regulated is critical for our understanding of both physiological and pathological conditions. Because these proteases require a reduced cysteine residue for activity, the cellular redox state plays a crucial role in regulating the activity of thiol proteases. Importantly, increased oxidative stress can result in the direct modification of the active site cysteine, leading to enzyme inactivation. This would suggest that oxidative stress that occurs during pathological insults could prolong cell survival by preventing the execution of thiol‐protease‐dependent cell death pathways. To test this hypothesis, cultured rat cortical neurons were treated with the oxidizing agent diamide or doxorubicin in the presence or absence of the calcium ionophore ionomycin. Under normoxic conditions, ionomycin treatment resulted in ∼70% cell death, which was prevented by addition of the calpain‐selective inhibitor benyzloxycarbonyl‐Leu‐Leu‐Tyr fluoromethylketone. Similarly, pretreatment of neurons with either oxidant was also protective. Protection resulting from oxidative stress was not due to new protein synthesis, insofar as cycloheximide did not affect oxidant‐mediated protection. Interestingly, treatment with the antioxidant Trolox to reverse or prevent oxidative stress blocked the protective effects of both oxidants against ionomycin‐induced cell death. We interpret these findings to suggest that, in diseases or conditions in which oxidative stress is increased, the ability of thiol‐proteases to execute cell death pathways fully is decreased and may prolong cell survival. © 2004 Wiley‐Liss, Inc.
Ca2+‐dependent glutamate release involves two classes of endoplasmic reticulum Ca2+ stores in astrocytes
Authors: Hua Xue , Malarkey Erik B. , Sunjara Vice , Rosenwald Steven E. , Li Wen‐hong , Parpura Vladimir 
Published: March 2004

AbstractAstrocytes can modulate synaptic transmission by releasing glutamate in a Ca2+‐dependent manner. Although the internal Ca2+ stores have been implicated as the predominant source of Ca2+ necessary for this glutamate release, the contribution of different classes of these stores is still not well defined. To address this issue, we cultured purified solitary cortical astrocytes and monitored changes in their internal Ca2+ levels and glutamate release into the extracellular space. Ca2+ levels were monitored by using the Ca2+ indicator fluo‐3 and quantitative fluorescence microscopy. Glutamate release was monitored by an L‐glutamate dehydrogenase‐linked detection system. Astrocytes were mechanically stimulated with a glass pipette, which reliably caused an increase in internal Ca2+ levels and glutamate release into the extracellular space. Although we find that the presence of extracellular Cd2+, a Ca2+ channel blocker, significantly reduces mechanically induced glutamate release from astrocytes, we confirm that internal Ca2+ stores are the predominant source of Ca2+ necessary for this glutamate release. To test the involvement of different classes of internal Ca2+ stores, we used a pharmacological approach. We found that diphenylboric acid 2‐aminoethyl ester, a cell‐permeable inositol 1,4,5‐trisphosphate (IP3) receptor antagonist, greatly reduced mechanically induced glutamate release. Additionally, the preincubation of astrocytes with caffeine or ryanodine also reduced glutamate release. Taken together, our data are consistent with dual IP3‐ and caffeine/ryanodine‐sensitive Ca2+ stores functioning in the control of glutamate release from astrocytes. © 2004 Wiley‐Liss, Inc.
Evolution of missing colorectal liver metastases following inductive chemotherapy and hepatectomy
Authors: Elias Dominique , Youssef Omar , Sideris Lucas , Dromain Clarisse , Baton Olivier , Boige Valérie , Ducreux Michel 
Published: March 2004

AbstractBackgroundA dramatic response to chemotherapy in some patients with multiple bilateral and initially unresectable liver metastases (LM) from colorectal cancer sometimes leads to their disappearance from imaging studies. Our study was aimed at assessing the evolution of these metastases when they were also not found during liver surgery.PatientsAmong 104 hepatectomized patients for colorectal LM in 4 years, 15 patients were retrospectively eligible. Eligibility criteria were: initially unresectable LM; a dramatic response to chemotherapy; and the complete disappearance of at least one LM on imaging studies (ultrasonography (US), computed tomography, and magnetic resonance) during more than 3 months. In four patients (27%), the disappeared LM could be found and treated at laparotomy. The main selection criterion for the 11 studied patients of this series was the impossibility of finding and treating the disappeared LM sited in the remaining liver after hepatectomy, resulting in “missing LM.”ResultsAfter a median follow‐up of 31 months (range: 18–55) for the series, eight patients among the eleven (73%) did not present any recurrence of the missing LM. The median follow‐up was 31.3 months for these eight patients. The three recurrences occurred respectively at 5, 5, and 8 months after surgery.ConclusionsThe disappearance of LM after chemotherapy on high‐quality imaging studies and after intra‐operative liver exploration resulted in their definitive cure in approximately 70% of cases. The current dogma stipulating an obligatory resection of the initially affected part of the liver is no longer acceptable. J. Surg. Oncol. 2004;86:4–9. © 2004 Wiley‐Liss, Inc.
Tolerance for immunosuppression in organ transplantation†
Authors: Stegall Mark D. , Platt Jeffrey L. 
Published: March 2004

Background
Insight into the mechanisms of organ engraftment and acquired tolerance has made it possible to facilitate these mechanisms, by tailoring the timing and dosage of immunosuppression in accordance with two therapeutic principles: recipient pretreatment and minimum use of posttransplant immunosuppression. We aimed to apply these principles in recipients of renal and extrarenal organ transplants.

Methods
82 patients awaiting kidney, liver, pancreas, or intestinal transplantation were pretreated with about 5 mg/kg of a broadly reacting rabbit antithymocyte globulin during several hours. Posttransplant immunosuppression was restricted to tacrolimus unless additional drugs were needed to treat breakthrough rejection. After 4 months, patients on tacrolimus monotherapy were considered for dose-spacing to every other day or longer intervals.

Findings
We frequently saw evidence of immune activation in graft biopsy samples, but unless this was associated with graft dysfunction or serious immune destruction, treatment usually was not intensified. Immunosuppression-related morbidity was virtually eliminated. 78 (95%) of 82 patients survived at 1 year and at 13-18 months. Graft survival was 73 (89%) of 82 at 1 year and 72 (88%) of 82 at 13-18 months. Of the 72 recipients with surviving grafts, 43 are on spaced doses of tacrolimus monotherapy: every other day (n = 6), three times per week (11), twice per week (15), or once per week (11).

Interpretation
The striking ability to wean immunosuppression in these recipients indicates variable induction of tolerance. The simple therapeutic principles are neither drug-specific nor organ-specific. Systematic application of these principles should allow improvements in quality of life and long-term survival after organ transplantation. (Lancet 2003;361:1502-1510)
A microstrip filter utilized in ultra‐wideband antennas
Authors: Wang Chien‐Jen , Lin Chia‐Horng , Wu Jin‐Wei 
Published: March 2004

AbstractIn this paper, a microstrip filter has been designed, fabricated, and measured for application in ultra‐wideband antennas. By using the combination of a band‐stop filter and a low‐pass filter, the band‐selective characteristics can be demonstrated. In order to enhance the suppression of the out‐of‐band signals, a defected ground structure (DGS) with stopband performance is used. The passband responses of the filter, which range below 2.8 GHz and from 5.0 to 6.0 GHz, cover most commercial wireless communication systems. The LC‐lumped equivalent circuit of the filter has been extracted and simulated by using transmission‐line analysis. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 248–251, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20107
An efficient and fast approach for surface‐wave pole extraction in two‐layered microstrip geometry
Authors: Wang Y. , Ooi B. L. , Leong M. S. 
Published: March 2004

AbstractAn efficient approach for fast evaluation of the poles' locations in two‐layered microstrip geometry has been presented. For the first time, good initial values and functional expressions with quadratic convergence for two‐layered pole extraction have been derived. Numerical comparison with available methods of extraction shows that our proposed method is very accurate and extremely fast in convergence. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 253–258, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20109
A thin wideband microstrip patch antenna with two adjacent slots
Authors: Yang G. , Ali M. , Dougal R. 
Published: March 2004

AbstractA thin (only 5% of the operating wavelength, λ) wideband microstrip patch antenna with two closely spaced slots is introduced. When connected to each other, the two slots translate into two distinct resonant frequencies, resulting in wide impedance bandwidth (about 20% within 2:1 VSWR). Detailed design data, including resonance frequency, impedance, and bandwidth, are presented as function of the antenna and slot parameters. It is also demonstrated that such antennas can be designed at different frequency bands by appropriately adjusting the antenna and slot parameters. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 261–266, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20111
Frequency‐selective surface based bandpass filters in the near‐infrared region
Authors: Govindaswamy Srikanth , East Jack , Terry Fred , Topsakal Erdem , Volakis John L. , Haddad George I. 
Published: March 2004

AbstractA spatial bandpass filter resonant at 1.5 μm and based on a frequency‐selective surface (FSS) was analyzed and fabricated. It consists of circular apertures arranged in a hexagonal lattice and was modeled using a hybrid finite‐element/boundary‐integral method, which accounted for metal thickness and conductivity. Measurements demonstrate the accuracy of the design. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 266–269, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20112
Design and fabrication of slant‐counter electrodes for optical switches
Authors: Dong Wei , Ruan Shengping , Zhang Xindong , Liu Caixia , Sun Dongming , Jia Cuiping , Pan Jianxuan , Ji Ping , Chen Weiyou 
Published: March 2004

AbstractThis paper describes electrostatically actuated micromechanical optical switches based on the slant‐counter electrode, and proposes an advanced method of fabricating the slant‐counter electrode. The pull‐in voltage and switching time are investigated. The slant‐counter electrode is fabricated by anisotropic wet etching of a (111) silicon wafer tilted at a 2.5° angle, which is normally tilted 2.5° off the 〈111〉 direction toward the nearest 〈110〉 direction. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 273–275, 2004; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002sol;mop.20115