bluuebunny/crossref_metadata_2025 huggingface dataset:
Block copolymer of trans‐polyisoprene and urethane segment: Crystallization behavior and morphology
Authors: Sun Xiaohui , Ni Xiuyuan
Published: October 2004

A new type of urethane segmented copolymer was prepared from hydroxyl‐terminated trans‐polyisoprene (HTTPI) and toluene diisocyanate (TDI). The structures of the copolymer were characterized by FTIR and GPC. Crystalline properties of trans‐polyisoprene (TPI) segments were investigated using WAXD and DSC techniques. The crystals of TPI segments are inclined to exist in low‐melting form (LM). The melting temperature of TPI shifts to a lower temperature as the urethane segment was introduced. DMA studies show that, when TPI crystals were at the melting state, the storage modulus of the copolymer depended on the content of urethane segment. The hard segment here serves as physical crosslinkage. Nonisothermal crystallization kinetics of TPI segment was studied on the basis of the Ozawa equation. It was found that the hard segment suppresses the crystallization of the TPI segment. Morphology of two‐phase separation was observed in the copolymer by SEM. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2286–2294, 2004
Recent developments in computational approaches for uncovering genomic homology
Authors: Simillion Cedric , Vandepoele Klaas , Van de Peer Yves
Published: October 2004

Identifying genomic homology within and between genomes is essential when studying genome evolution. In the past years, different computational techniques have been developed to detect homology even when the actual similarity between homologous segments is low. Depending on the strategy used, these methods search for pairs of chromosomal segments between which either both gene content and order are conserved or gene content only. However, due to fact that, after their divergence, homologous segments can lose a different set of genes, these methods still often fail to detect genomic homology. Recently, more advanced approaches have been developed that can combine gene order and content information of multiple genomic segments. BioEssays 26:1225–1235, 2004. © 2004 Wiley Periodicals, Inc.
The source(s) for new pancreatic beta cells in adult life
Authors: Bock Troels
Published: October 2004

The natural source for new pancreatic beta cells is an important issue both for understanding the pathogenesis of diabetes, and for possibly curing diabetes by increasing the number of beta cells. Dor et al.1 investigated beta‐cell renewal and regeneration by genetic lineage analysis in mice during physiological growth and after partial pancreatectomy. The data conclusively showed that beta‐cell replication was the only source for new beta cells without contributions from stem cells or other non‐beta cells. This underlines the capacity for beta‐cell self‐renewal and casts doubt that other cell types are able to generate new beta cells in the intact pancreas. BioEssays 26:1156–1159, 2004. © 2004 Wiley Periodicals, Inc.
A synthetic peptide reproducing the mitochondrial targeting motif of AKAP121: A conformational study
Authors: De Capua Antonia , Del Gatto Annarita , Zaccaro Laura , Saviano Gabriella , Carlucci Annalisa , Livigni Alessandra , Gedressi Chiara , Tancredi Teodorico , Pedone Carlo , Saviano Michele
Published: October 2004

The conformational features of a peptide derived by the 10–30 sequence of the mitochondrial domain of AKAP121 [Ac‐1XKKPLALPGMLALLGWWWFFSRKKX25‐NH2 (X = β‐Ala)] in water and in a water/triflouroethanol (TFE) mixture at 298 K have been determined by NMR and CD spectroscopy. Backbone clustering analysis of NMR‐derived structures led to the identification of a single representative structure in water/TFE. The structure of the peptide consists mainly of an α‐helix, whose core is the region 7–23, with a less ordered N‐terminal part. These data are confirmed by CD analysis. It is noteworthy that the high hydrophobic Trp16–Phe20 segment, that might also mediate interaction with tubulin, is organized in an α‐helical wheel. Our conformational data can be the starting point for the development of highly selective peptides that interfere with the biological function of the Protein Kinase A scaffold protein AKAP121. © 2004 Wiley Periodicals, Inc. Bioploymers (Pept Sci), 2004
Induction of signaling pathways by herpes simplex virus type 1 through glycoprotein H peptides
Authors: Galdiero Stefania , Vitiello Mariateresa , D'Isanto Marina , Di Niola Erminia , Peluso Lucia , Raieta Katia , Pedone Carlo , Galdiero Massimiliano , Benedetti Ettore
Published: October 2004

Eukaryotic cells respond to extracellular stimuli, such as viruses, by recruiting signal transduction pathways, many of which are mediated through activation of distinct mitogen‐activated protein kinase (MAPK) cascades and activation of transductional regulation factors. The best characterized of this pathway are the extracellular signal regulated Kinase (ERK), the c‐Jun N‐terminal kinase/stress activated protein kinase (JNK/SAPK), and the p38 MAPK cascade.

Herpes simplex virus type 1 (HSV‐1) encodes at least 11 envelope glycoproteins, which alone or in concert play different roles in viral adsorption, entry, cell‐to‐cell spread, and immune evasion. Of these proteins, three are designated glycoprotein B (gB), glycoprotein D (gD), and the gH/gL heterodimer, are clearly involved in attachment and entry, and therefore possible candidates in inducing early cellular activation.

Nevertheless, the precise role of each glycoprotein and the cellular factor involved remain elusive. The signal transduction pathways involved, and the outcome of cellular activation on viral entry or postentry events, are still to be elucidated. To better understand the role of signal transduction pathways and phosphorylation events in HSV‐1 entry, synthetic peptides modeled on HSV‐1 gH were synthesized and tested for MEK1‐MEK2/MAPK cascade activation. Our results show a major involvement of the JNK pathway in the intracellular signal transmission after stimulation with gH HSV‐1 peptides. © 2004 Wiley Periodicals, Inc. Biopolymers (Pept Sci), 2004
Die Einsamkeit des Amateurs. Hobby‐ und Dandy‐Chemiker in ihren Laboratorien
Authors: Krätz Otto
Published: October 2004

Dem Hobby‐ und Amateur‐Chemiker [1] kommt in der Literatur in der Regel eine besondere Aufgabe zu: Er bereichert das Repertoire der Literaten mit seltsam‐unheimlichen, aber besiegbaren und daher selten wirklich apokalyptischen Figuren. Die folgende Betrachtung schöpft in einer Anzahl von Beispielen aus der schöngeistigen Literatur, aber auch aus Biographien etc. und ist ausschließlich dem Amateur‐Alchemisten und Amateur‐Chemiker gewidmet. Amateure sind auf sich gestellt. Ihr besonderes Kennzeichen ist die Ferne zu ihrer Umgebung.
Resublimation — die faszinierende Bildung von Raureif
Authors: de Vries Tönjes , Paschmann Antje
Published: October 2004

Wer kennt sie nicht — diese ganz besondere Atmosphäre an einem kalten sonnigen Wintermorgen, wenn die Welt in einen weißen Schleier aus Raureif gehüllt ist. Sieht man genau hin, so erkennt man, dass es sich dabei um kleine nadelförmige Strukturen aus Eis handelt, die z. B. an Grashalmen und Zweigen haften. Hinter diesem Phänomen verbirgt sich der Vorgang der Resublimation.

Im vorliegenden Beitrag werden Untersuchungsergebnisse vorgestellt, die belegen, dass Schüler z. T. große Schwierigkeiten haben, das beschriebene Phänomen angemessen zu erklären. Es werden Experimente vorgestellt, die auf einfache Weise den Vorgang der Resublimation zeigen und eine Erarbeitung des Phänomens erlauben. Gleichzeitig bieten diese Versuche die Möglichkeit, das faszinierende Wachstum fraktaler Eiskristalle gewissermaßen „live”︁ mitzuerleben. In einigen Klassen des 7. Jahrgangs sind diese Experimente bereits im Unterricht erprobt worden.
Plädoyer für den Einsatz der Gaschromatographie im Unterricht
Authors: Wiederholt Erwin , Fahrney Volker
Published: October 2004

Selbst in wirtschaftlich angespannten Zeiten lässt sich die Gaschromatographie im Chemieunterricht einsetzen. Trennungen von Gasgemischen werden bei Raumtemperatur mit dem Minimal‐Gaschromatograph als vollwertigem Gaschromatographen ausgeführt. Mit zwei hintereinandergeschalteten Minimal‐Gaschromatographen wird der Nachweis und oft sogar die Identifizierung einzelner Gemischkomponenten möglich oder erleichtert.
MRI‐monitored electromagnetic heating using iterative feedback control and phase interference mapping
Authors: Behnia B. , Webb A.G.
Published: October 2004

Noninvasive electromagnetic hyperthermia, used in combination with radiotherapy or chemotherapy, is a promising technique in the treatment of large, deep‐lying tumours. One of the major difficulties in effective implementation, however, is that the spatial distribution of electric fields within the patient is strongly influenced by tissue morphology and dielectric properties, and is therefore difficult to model. Even when desired heating profiles are achieved experimentally, the specific absorption rate at the focus generally does not reach its theoretical maximum value since the E‐fields are not completely coherent. In this article, a new method, phase interference mapping, is developed to address this latter problem and is demonstrated in phantoms. The complete process for optimizing spatial and temporal control of electromagnetic heating has three separate steps. The first involves phase calibration of the individual dipoles of a phased array applicator with a noninvasive E‐field probe placed on the surface of the phantom. In the second step, an iterative feedback method is used to rapidly steer the thermal focus as close as possible to the desired location. Noninvasive mapping of the temperature and specific absorption rate is realized by magnetic resonance imaging. The final step in the process consists of phase interference mapping of the dipoles, to maximize E‐field coherence. Temporal control of the temperature rise or specific absorption rate can then be performed. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 23B: 1–15, 2004
Prenatal development of the rodent rostral migratory stream
Authors: Pencea Viorica , Luskin Marla B.
Published: October 2004

The aim of this study was to elucidate the embryological origins of the unique neuronal progenitor cells that form the rostral migratory stream (RMS), the path traversed by cells from the anterior part of the forebrain subventricular zone (SVZa) en route to the olfactory bulb. To determine when and where cells constituting the RMS initially exhibit their characteristic neuronal phenotype and high mitotic capacity, we analyzed the cells of the rat forebrain between embryonic day 14 (E14) and postnatal day 2 (P2). At E14, cells with a neuronal phenotype were observed within the ventricular zone in close proximity to the mantle layer of the future olfactory bulb. By E15, cells expressing neuronal markers are also PSA‐NCAM immunoreactive and become aligned in chains of similarly oriented cells, a hallmark of the postnatal RMS. The cells that form chains organize into a patch that enlarges in the anterior‐posterior and medial‐lateral dimensions from E16 to E22 (birth). In comparing the forebrain cytoarchitecture to the pattern of cell type‐specific staining, the patch constitutes only the central part of the proximal RMS. Early during development, the region of the RMS surrounding the patch expresses low levels of PSA‐NCAM and neuron‐specific markers. The proliferative activity of cells forming the patch vs. nonpatch regions of the RMS was analyzed following a short bromodeoxyuridine (BrdU) exposure. Between E15 and E22, the patch can be recognized by the mitotic activity of its cells; the cells of the patch incorporate less BrdU than the nonpatch portion of the RMS. The time course of appearance of cells forming the RMS indicates that the RMS arises in advance and independently of the cortical SVZ. Although the patch and the nonpatch regions of the embryonic RMS appear to merge postnatally, the two regions may originate separately under the influence of distinct intrinsic and extrinsic factors. J. Comp. Neurol. 463:402–418, 2003. © 2003 Wiley‐Liss, Inc.
Solubility studies on valdecoxib in the presence of carriers, cosolvents, and surfactants
Authors: Desai Kashappa Goud H. , Park Hyun J.
Published: October 2004

Enhancement of the solubility of valdecoxib was examined using a series of hydrophilic carriers (mannitol, polyethylene glycol (PEG) 4000, PEG 6000, PEG 8000, and urea), surfactants (Tween‐20, Tween‐80, and sodium lauryl sulfate [SLS]) and cosolvents (ethanol, methanol, and glycerol) at 37°C. The solubility of valdecoxib could be enhanced significantly using PEG 4000 as a carrier, ethanol as cosolvent, and SLS as a surfactant. Because the solubility of valdecoxib increased dramatically in the presence of polyethylene glycols, these are suitable dispersing agents for preparing solid dispersions containing valdecoxib. Gibbs free energy (ΔG) values were all negative for all hydrophilic carriers tested, indicating the spontaneous nature of valdecoxib solubilisation. Among the cosolvents, ethanol exhibited higher solubilization potential than methanol and glycerol. As the dielectric constant of the cosolvent–water mixtures decreased, the solubility of valdecoxib increased. Finally, SLS exerted maximum solubilization of valdecoxib when compared to Tween‐20 or Tween‐80. The crystallinity of valdecoxib was explored by X‐ray diffraction study and showed numerous crystalline peaks. Examination of surface morphology by scanning electron microscopy depicted a near spherical shape of valdecoxib with irregular surface characteristics. Drug Dev. Res. 62:41–48, 2004. © 2004 Wiley‐Liss, Inc.
Msx2 controls ameloblast terminal differentiation
Authors: Bei Marianna , Stowell Stephanie , Maas Richard
Published: October 2004

Late tooth morphogenesis is characterized by a series of events that determine cusp morphogenesis and the histodifferentiation of epithelial cells into enamel‐secreting ameloblasts. Mice lacking the homeobox gene Msx2 exhibit defects in cusp morphogenesis and in the process of amelogenesis. To better understand the basis of the Msx2 mutant tooth defects, we have investigated the function of Msx2 during late stages of tooth morphogenesis. Cusp formation is thought to be under the control of the enamel knot, which has been proposed to act as an organizing center during this process (Vaahtokari et al. [ 1996] Mech. Dev. 54:39–43). Bone morphogenetic protein‐4 (BMP4) has been suggested to mediate termination of enamel knot signaling by means of regulation of programmed cell death (Jernvall et al. [ 1998] Development 125:161–169). Here, we show that Bmp4 expression in the enamel knot is Msx2‐dependent. We further show that during amelogenesis Msx2 is required for the expression of the extracellular matrix gene Laminin 5 alpha 3, which is known to play an essential role during ameloblast differentiation. This result thus provides a paradigm for understanding how transcription factors and extracellular matrix can be integrated into a developmental pathway controlling cell differentiation. Developmental Dynamics 231:758–765, 2004. © 2004 Wiley‐Liss, Inc.
Partially overlapping expression of Gata2 and Gata3 during inner ear development
Authors: Lilleväli Kersti , Matilainen Tanja , Karis Alar , Salminen Marjo
Published: October 2004

Gata2 and Gata3 belong to the Gata family of transcription factors in vertebrates that bind to a consensus “GATA” DNA sequence. The Gata3 gene is one of the earliest markers for the developing mouse inner ear. Ear morphogenesis is blocked in Gata3‐deficient embryos, whereas nothing was known of the role of Gata2 in mouse inner ear. Here, we have compared the expression patterns of Gata2 and Gata3 during normal inner ear development and investigated their relationship in mice where either Gata3 or Gata2 has been inactivated. The expression of the two Gata genes is highly overlapping at embryonic day (E)10.5 but becomes increasingly distinct later. Whereas Gata2 is predominantly expressed in the dorsal vestibular system, Gata3 was detected mainly in the ventral cochlear duct and ganglion. No phenotypic abnormalities were observed in the inner ear of Gata2−/− embryos before lethality at E10.5 and Gata3 expression was unchanged. In contrast, a delay and strong reduction of Gata2 expression was detected in Gata3−/− otic epithelium. Developmental Dynamics 231:775–781, 2004. © 2004 Wiley‐Liss, Inc.
NMR Study of L‐Shaped (Quinoxaline)platinum(II) Complexes − Crystal Structure of [Pt(DMeDPQ)(bipy)](PF6)2
Authors: Rotondo Enrico , Rotondo Archimede , Nicolò Francesco , Di Pietro Maria Letizia , Messina Maria Anna , Cusumano Matteo
Published: October 2004

A 1H and 13C NMR study of nine PtII complexes of DMeDPQ [6,7‐dimethyl‐2,3‐bis(2‐pyridyl)quinoxaline] and BDPQ [2,3‐bis(2‐pyridyl)benzo[g]quinoxaline], and the crystal structure of one of them, are reported. The results are consistent with Cs symmetry of “L‐shaped square‐planar complexes”. The rigid seven‐membered chelated quinoxaline ligand holds the fused aromatic rings nearly perpendicular to the PtII coordination plane, generating the peculiar L‐shaped structure. Ancillary ligands in the residual coordination sites are: a) bidentate flexible‐planar 2,2′‐bipyridine (bipy; complexes 1 and 2); b) bidentate rigid‐planar dipyrido[3,2‐a:2′3′‐c]phenazine (dppz) or benzo[b]dipyrido[3,2‐h:2′,3′‐j]phenazine (bdppz; complexes 3−6); or c) 3‐substituted monodentate pyridines (3‐Rpy; complexes 7−9). The L‐shaped geometry has been exploited to gain insight into the steric and dynamic features that regulate the noncovalent interactions of these square‐planar complexes with DNA. We have shown previously, for [Pt(bipy)(n‐Rpy)2]2+, that bipy twisting can be frozen out on the NMR timescale below 260 K. Preservation of the Cs symmetry at low temperature indicates a lack of bipy fluxionality within these L‐shaped structures. The static butterfly‐like symmetric orientation of the quinoxaline pyridyl rings accounts for the hampered twisting of Pt(bipy), which is otherwise assisted by the synchronous “windscreen wiper” conrotatory rocking of the ancillary pyridine rings. The L‐geometry can also be used to monitor the ancillary n‐Rpy rotation by NMR spectroscopy. The quasi‐vertical quinoxaline pyridyl rings alignment leave room in the coordination plane for the crossing of the opposite pyridine rings, thereby reducing their rotational barriers about the Pt−N bond. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Potentiation of the osmosensitive taurine release and cell volume regulation by cytosolic Ca2+ rise in cultured cerebellar astrocytes
Authors: Cardin Velia , Lezama Ruth , Torres‐Márquez M. Eugenia , Pasantes‐Morales Herminia
Published: October 2004

Hyposmolarity (−30%) in cultured cerebellar astrocytes raised cytosolic Ca2+ concentration ([Ca2+]i) from 160 to 400 nM and activated the osmosensitive taurine release (OTR) pathway. Although OTR is essentially [Ca2+]i‐independent, further increase in [Ca2+]i by ionomycin strongly enhanced OTR, with a more robust effect at low and mild osmolarity reductions. Ionomycin did not affect isosmotic taurine efflux. OTR was decreased by tyrphostin A25 and increased by ortho‐vanadate, suggesting a modulation by tyrosine kinase or phosphorylation state. Inhibition of phosphatidylinositol‐3‐kinase activity by wortmannin markedly decreased OTR and the ionomycin increase. Conversely, OTR and the ionomycin effect were independent of ERK1/ERK2 activation. OTR and its potentiation by ionomycin differed in their sensitivity to CaM and CaMK blockers and in the requirement of an intact cytoskeleton for the ionomycin effect, but not for normal OTR. Changes in the actin cytoskeleton organization elicited by hyposmolarity were not observed in ionomycin‐treated cells, which may permit the operation of CaM/CaMK pathways involved in the OTR potentiation by [Ca2+]i rise. OTR potentiation by [Ca2+]i requires the previous or simultaneous activation/operation of the taurine release mechanism and is not modifying its set point, but rather increasing the effectiveness of the pathway, resulting in a more efficient volume regulation. This may have a beneficial effect in pathological situations with concurrent swelling and [Ca2+]i elevation in astrocytes. © 2003 Wiley‐Liss, Inc.
GABAA receptor‐expressing astrocytes in the supraoptic nucleus lack glutamate uptake and receptor currents
Authors: Israel Jean‐Marc , Schipke Carola G. , Ohlemeyer Carsten , Theodosis Dionysia T. , Kettenmann Helmut
Published: October 2004

An important function of astrocytes is the clearance of excess extracellular glutamate via specific carriers whose expression has become an astrocytic marker. In the present study, we found that a large population of astrocytes in the supraoptic nucleus (SON) of the rat hypothalamus lacks glutamate uptake currents and receptor responses but expresses GABAA receptors. Patch clamp recordings in acute hypothalamic slices that included the SON showed typical astrocytic membrane currents and demonstrated that GABA, via GABAA receptor activation, triggered a conductance increase with the reversal potential close to the Cl− equilibrium potential and a decrease in resting K+ conductance. Intracellular labeling with Lucifer Yellow revealed that these cells had a radial glia‐like morphology, with cell bodies lined up along the base of the brain and long processes traversing the nucleus; they were not dye‐coupled. Parallel immunocytochemical labelings showed that they expressed strong GABAA receptor and glial fibrillary acidic protein (GFAP) immunoreactivities. In addition, our electrophysiological and morphological analyses revealed another population of astrocytes in this nucleus, located next to the subarachnoid space. They were less numerous than the radial type, had a round morphology and few processes, and were dye‐coupled. Unlike the radial astrocytes, they showed little immunoreactivity for GABAA receptor or GFAP. Moreover, they did not respond to GABA but to glutamate, a response that was partially mimicked by aspartate, indicating glutamate transporter expression. Taken together, our observations add to growing evidence illustrating heterogeneity of astrocytes in the adult brain, a heterogeneity that reflects striking differences in form and function of astrocytic populations in regions as discrete as the SON of the hypothalamus. © 2003 Wiley‐Liss, Inc.
Estimation of absolute microglial cell numbers in mouse fascia dentata using unbiased and efficient stereological cell counting principles
Authors: Wirenfeldt Martin , Dalmau Ishar , Finsen Bente
Published: October 2004

Stereology offers a set of unbiased principles to obtain precise estimates of total cell numbers in a defined region. In terms of microglia, which in the traumatized and diseased CNS is an extremely dynamic cell population, the strength of stereology is that the resultant estimate is unaffected by shrinkage or expansion of the tissue. The optical fractionator technique is very efficient but requires relatively thick sections (e.g., ≥20 μm after coverslipping) and the unequivocal identification of labeled cells throughout the section thickness. We have adapted our protocol for Mac‐1 immunohistochemical visualization of microglial cells in thick (70 μm) vibratome sections for stereological counting within the murine hippocampus, and we have compared the staining results with other selective microglial markers: the histochemical demonstration of nucleotide diphosphatase (NDPase) activity and the tomato lectin histochemistry. The protocol gives sections of high quality with a final mean section thickness of >20 μm (h = 22.3 μm ± 0.64 μm), and with excellent rendition of Mac‐1+ microglia through the entire height of the section. The NDPase staining gives an excellent visualization of microglia, although with this thickness, the intensity of the staining is too high to distinguish single cells. Lectin histochemistry does not visualize microglia throughout the section and, accordingly, is not suited for the optical fractionator. The mean total number of Mac‐1+ microglial cells in the unilateral dentate gyrus of the normal young adult male C57BL/6 mouse was estimated to be 12,300 (coefficient of variation (CV) = 0.13) with a mean coefficient of error (CE) of 0.06. The perspective of estimating microglial cell numbers using stereology is to establish a solid basis for studying the dynamics of the microglial cell population in the developing and in the injured, diseased and normal adult CNS. © 2003 Wiley‐Liss, Inc.
Human oligodendrocyte precursor cells in vitro: Phenotypic analysis and differential response to growth factors
Authors: Wilson Heather C. , Onischke Claus , Raine Cedric S.
Published: October 2004

Following experimental demyelination in rodents, oligodendrocyte precursor cells (OPCs) proliferate and differentiate into myelin‐producing oligodendrocytes which effect robust remyelination. In contrast, remyelination in multiple sclerosis, the major human demyelinating disease, is generally limited and transient. Rodent OPCs have been well characterized in vitro and their response to growth factors documented. Since there appear to be appreciable species differences in OPC growth factor responsiveness, and since human precursors have proven difficult to culture, the present study has investigated mitogenic growth factors for cultured fetal human OPCs. Moreover, because markers for cultured human OPCs are not well established, we also examined which of the extensively used rodent OPC markers also label human precursors. Using a culture system modified for fetal human oligodendroglia, we have shown for the first time that the platelet‐derived growth factor α receptor (PDGFαR) and A2B5 antigen are expressed together on human OPCs. Human precursors also expressed NG2 chondroitin sulfate proteoglycan, as did a proportion of O4+ preoligodendrocytes. Several growth factors known to affect rodent OPCs were tested and found to have similar effects on human cells. PDGF, neurotrophin 3 (NT3), and glial growth factor 2 (GGF2) promoted proliferation, while insulin‐like growth factor‐1 (IGF‐1), exerted a maturational effect. © 2003 Wiley‐Liss, Inc.
Early loss of astrocytes after experimental traumatic brain injury
Authors: Zhao Xueren , Ahram Abdullah , Berman Robert F. , Muizelaar J. Paul , Lyeth Bruce G.
Published: October 2004

Neuronal‐glial interactions are important for normal brain function and contribute to the maintenance of the brain's extracellular environment. Damage to glial cells following traumatic brain injury (TBI) could therefore be an important contributing factor to brain dysfunction and neuronal injury. We examined the early fate of astrocytes and neurons after TBI in rats. A total of 27 rats were euthanized at 0.5, 1, 2, 4, or 24 h after moderate lateral fluid percussion TBI or after sham TBI. Ipsilateral and contralateral hippocampi were examined in coronal sections from −2.12 to −4.80 mm relative to bregma. Adjacent sections were processed with markers for either astrocytes or degenerating neurons. Astrocytes were visualized using glial fibrillary acidic protein (GFAP) or glutamine synthetase immunohistochemistry. Neuronal degeneration was visualized using Fluoro‐Jade (FJ) histofluorescence. At 30 min, there was a significant loss of GFAP immunoreactivity in ipsilateral hippocampal CA3 with some loss of normal astrocyte morphology in the remaining cells. The number of normal staining astrocytes decreased progressively over time with extensive astrocyte loss at 24 h. At 4 h, lightly stained FJ‐positive neurons were scattered in the ipsilateral CA3. The intensity and number of FJ‐positive neurons progressively increased over time with moderate numbers of degenerating neurons in the ipsilateral hippocampal CA3 evident at 24 h. We conclude that astrocyte loss occurs in the hippocampus early after TBI. The data suggest that loss of supporting glial cell may contribute to subsequent neuronal degeneration. © 2003 Wiley‐Liss, Inc.
Effects of electroacupuncture versus manual acupuncture on the human brain as measured by fMRI
Authors: Napadow Vitaly , Makris Nikos , Liu Jing , Kettner Norman W. , Kwong Kenneth K. , Hui Kathleen K.S.
Published: October 2004

The goal of this functional magnetic resonance imaging (fMRI) study was to compare the central effects of electroacupuncture at different frequencies with traditional Chinese manual acupuncture. Although not as time‐tested as manual acupuncture, electroacupuncture does have the advantage of setting stimulation frequency and intensity objectively and quantifiably. Manual acupuncture, electroacupuncture at 2 Hz and 100 Hz, and tactile control stimulation were carried out at acupoint ST‐36. Overall, electroacupuncture (particularly at low frequency) produced more widespread fMRI signal increase than manual acupuncture did, and all acupuncture stimulations produced more widespread responses than did our placebo‐like tactile control stimulation. Acupuncture produced hemodynamic signal increase in the anterior insula, and decrease in limbic and paralimbic structures including the amygdala, anterior hippocampus, and the cortices of the subgenual and retrosplenial cingulate, ventromedial prefrontal cortex, frontal, and temporal poles, results not seen for tactile control stimulation. Only electroacupuncture produced significant signal increase in the anterior middle cingulate cortex, whereas 2‐Hz electroacupuncture produced signal increase in the pontine raphe area. All forms of stimulation (acupuncture and control) produced signal increase in SII. These findings support a hypothesis that the limbic system is central to acupuncture effect regardless of specific acupuncture modality, although some differences do exist in the underlying neurobiologic mechanisms for these modalities, and may aid in optimizing their future usage in clinical applications. Hum. Brain Mapping 24:193–205, 2005. © 2004 Wiley‐Liss, Inc.
Encapsulation of biologics in self‐assembled fibers as biostructural units for tissue engineering
Authors: Wan Andrew C. A. , Yim Evelyn K. F. , Liao I‐Chien , Le Visage Catherine , Leong Kam W.
Published: October 2004

The concept of a “biostructural unit” is presented as the combination of biological and structural building blocks to create scaffolds or constructs via a bottom‐up approach. Three types of biostructural units were constructed using the process of fiber formation by interfacial polyelectrolyte complexation: protein‐encapsulated fiber, ligand‐immobilized fiber, and cell‐encapsulated fiber units. Water‐soluble chitin (WSC) and alginate were used as the polyelectrolyte combination to form fiber. Encapsulation and sustained release of bovine serum albumin from the fiber could be achieved, release profiles being dependent on the WSC/alginate concentration ratio. Released nerve growth factor (NGF) retained its bioactivity, as demonstrated on PC12 cells. Biotinylated fiber could be fabricated by biotinylating alginate before drawing fiber with WSC, enabling biotinylated NGF to be immobilized to fiber via an avidin bridge. The immobilized NGF induced the differentiation of PC12 cells seeded on the fiber. Bovine pulmonary endothelial cells, human dermal fibroblasts, and human mesenchymal stem cells were encapsulated, demonstrating good viability as determined by Live/Dead and WST‐1 assays. The assembly of biostructural units into constructs was illustrated by using human mesenchymal stem cell–encapsulated fiber units. Cells in the resulting constructs could be induced to differentiate along chondrogenic and osteogenic lineages. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 586–595, 2004
The ABCs of cash management
Authors: Payne Chris
Published: October 2004

The author offers a step‐by‐step guide of easy‐to‐implement processes that speed up customer payments—resulting in greater efficiency and bottom‐line results. © 2004 Wiley Periodicals, Inc.
Speed up collections with the latest technology
Authors: Bean LuAnn
Published: October 2004

The latest technology can dramatically shrink the time it takes to collect receivables. Called EIPP (Electronic Invoice Presentment and Payment), this evolving breed of software is finally ready for widespread use. © 2004 Wiley Periodicals, Inc.
The dirty dozen: Tough treasury problems and how to solve them
Authors: Sagner James S.
Published: October 2004

Due to recent recessions, many companies have downsized or outsourced critical functions. Treasury and Finance have suffered, as entire departments were eliminated. What's worse, companies have grown lax about optimizing cash use while retaining adequate controls. The author presents a dirty dozen of the toughest problems companies are wrestling with—and shows you how to handle them. © 2004 Wiley Periodicals, Inc.
Check fraud: Beware standard bank agreements!
Authors: Turner Paul S. , Wunnicke Diane B.
Published: October 2004

Who is liable for a fraudulent check—your company or the bank? Read your bank deposit and positive pay agreements carefully. The answer may alarm you! © 2004 Wiley Periodicals, Inc.
VIEs shift billions back to the bottom line
Authors: Bean LuAnn , Jarnagin Bill
Published: October 2004

Variable interest entities (VIEs), recently established by the FASB, force companies to hit their balance sheets with huge amounts of assets and liabilities. Exactly what are VIEs, and why is the FASB doing this? Is it a bold move to spark investor confidence or an unwise shock to the market? And what will the effect be on corporate restructuring and mergers?© 2004 Wiley Periodicals, Inc.
Relationship between vertebral bone marrow blood perfusion and common carotid intima‐media thickness in aging adults
Authors: Chen Wei‐Tsung , Ting‐Fang Shih Tiffany , Hu Chaur‐Jong , Chen Ran‐Chou , Tu Hsing‐Yang
Published: October 2004

Purpose

To evaluate the relationship between vertebral marrow blood perfusion and common carotid intima‐media thickness (IMT) in aging adults.

Materials and Methods

An age‐ and sex‐matched case control study was conducted. Subjects were contacted and enrolled voluntarily according to a database containing 2258 cases that received carotid ultrasonography examination at our hospital in the previous two years. Forty‐three pairs of subjects (56 male, 30 female; aged 44–85 years, average 63 years) underwent dynamic contrast‐enhanced magnetic resonance (MR) study of the lumbar spine. The average peak enhancement percentage of the second to fourth lumbar vertebrae was used to represent the vertebral marrow perfusion status for each subject. The common carotid IMT, presence of plaque, peak enhancement percentage, body mass index (BMI), systolic and diastolic blood pressure, serum total cholesterol, high‐density lipoprotein (HDL), and triglycerol levels were acquired for statistical analysis.

Results

The average peak enhancement percentage was significantly lower in thickened IMT group compared to the normal IMT group (73 ± 23 vs. 90 ± 27, P = 0.0023). The carotid IMT inversely correlated with vertebral peak enhancement percentage (r = −0.33, P = 0.0018). The vertebral peak enhancement percentage was significantly lower in subjects with presence of any carotid plaque (P = 0.032). Common carotid IMT was the only significant variable that was negatively associated with vertebral marrow perfusion after adjusting for the effect of sex, age, blood pressure, BMI, total cholesterol, HDL, and triglycerol level in linear regression model (P = 0.008).

Conclusion

Our data demonstrate the negative association between vertebral marrow blood perfusion and common carotid IMT. These results suggest that common carotid IMT may provide the information of tissue perfusion status of the vertebral bone marrow. J. Magn. Reson. Imaging 2004;20:811–816. © 2004 Wiley‐Liss, Inc.
Effective blood signal suppression using double inversion‐recovery and slice reordering for multislice fast spin‐echo MRI and its application in simultaneous proton density and T2 weighted imaging
Authors: Kuribayashi Hideto , Tessier Jean J. , Checkley David R. , Wang Yi‐Xiang , Hultin Leif , Waterton John C.
Published: October 2004

Purpose

To design a multislice double inversion‐recovery fast spin‐echo (FSE) sequence, with k‐space reordered by inversion time at slice position (KRISP) technique, to produce black‐blood vessel wall magnetic resonance imaging (MRI).

Materials and Methods

In this sequence, central k‐space sampling for each slice is required at inversion time (TI) of the blood signal. To fill the entire k‐space, the peripheral lines are obtained less or greater the TI and using a rotating slice order. Blood flow signal suppression was first evaluated using a phantom. Simulation studies were used to investigate FSE image quality. The final sequence was then applied to the rabbit abdominal aorta MRI at 4.7 T.

Results

In the flow phantom study, artifacts from slow‐flowing water were substantially reduced by the KRISP technique; residual water spins were dephased by the strong phase‐encoding gradient required for peripheral k‐space. These dephased spins flowed into the slice plane where the center of k‐space was being acquired at the TI of the flowing water signal. Multislice black‐blood MR images were successfully obtained in the rabbit abdomen using the sequence with the k‐trajectory optimized by the simulation study.

Conclusion

The KRISP technique was effective both in multislice double inversion‐recovery FSE and in blood signal suppression. J. Magn. Reson. Imaging 2004;20:881–888. © 2004 Wiley‐Liss, Inc.
Pancreatic sarcoidosis: MRI features
Authors: Baroni Ronaldo H. , Pedrosa Ivan , Tavernaraki Ekaterini , Goldsmith Jeffrey , Rofsky Neil M.
Published: October 2004

Pancreatic sarcoidosis is a rare entity, and few reports in the literature describe the CT aspects of the disease. We report the MR features of a pathologically‐confirmed case of pancreatic sarcoidosis, which presented as multiple pancreatic masses with low signal intensity on T1‐weighted images, mild high signal intensity on T2‐weighted images, and decreased enhancement compared to the normal pancreas after administration of gadolinium. Pancreatic sarcoidosis should therefore be included in the differential diagnosis of multiple pancreatic masses with these MRI features. J. Magn. Reson. Imaging 2004;20:889–893. © 2004 Wiley‐Liss, Inc.
Protease‐activated receptor subtype expression in developing eye and adult retina of the rat after optic nerve crush
Authors: Rohatgi T. , Sedehizade F. , Sabel B.A. , Reiser G.
Published: October 2004

Protease‐activated receptors (PARs), 7‐transmembrane domain G protein‐coupled receptors, are involved in tissue degeneration and repair upon injury. We demonstrate the expression of all four PAR subtypes in the postnatal eye and in retina of the adult rat by reverse transcription‐polymerase chain reaction (RT‐PCR). PAR‐1 is regulated developmentally in the eye, with a decrease from P1, P9, to P16, whereas levels for PAR‐2, PAR‐3, and PAR‐4 remain unchanged throughout. In the retina of the adult rat, PAR‐1 is highly expressed, whereas PAR‐2 and PAR‐3 are moderately expressed, compared to low PAR‐4 expression. To elucidate possible roles of PARs after trauma, we carried out semiquantitative RT‐PCR analysis of expression of all 4 PAR subtypes, beginning 6 hr after partial optic nerve crush (ONC) in the adult rat until 3 weeks after the mild trauma. Levels of PAR mRNA for all four subtypes were upregulated as early as 6 hr after unilateral ONC, except PAR‐3, which showed a delayed upregulation. PAR‐1, PAR‐3, and PAR‐4 mRNA levels returned to almost basal levels at 3 weeks post‐crush, whereas PAR‐2 mRNA level was still high by the end of 3 weeks after crush. Although the lesion was unilateral, PAR mRNA expression in the contralateral, uninjured side was affected to levels almost comparable to those in the injured side. Previous studies have shown an increase in thrombin levels at the site of injury, retinal ganglion cell degeneration by necrosis and apoptosis, and PAR activation as consequences of nerve crush. PAR upregulation because of nerve crush in the mild trauma model could act as an effector of early cell death. Eventual return of receptor mRNA to basal levels is consistent with neuroprotection. © 2003 Wiley‐Liss, Inc.
Ascorbate‐induced differentiation of embryonic cortical precursors into neurons and astrocytes
Authors: Lee Ji‐Yeon , Chang Mi‐Yoon , Park Chang‐Hwan , Kim Hye‐Young , Kim Jin‐Hyuk , Son Hyeon , Lee Yong‐Sung , Lee Sang‐Hun
Published: October 2004

A specific role for ascorbate (AA) in brain development has been postulated based on a rise of AA levels in fetal brain (Kratzing et al., 1985). To evaluate the role of AA during CNS development, we analyzed the survival, proliferation, and differentiation of AA‐treated CNS precursor cells isolated from rat embryonic cortex. Immunocytochemical analyses revealed that AA promoted the in vitro differentiation of CNS precursor cells into neurons and astrocytes in a cell density‐dependent manner. Additionally, AA increased the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) of postmitotic neurons in primary neuronal cultures. Differential expression analysis of genes specific to neuronal or glial differentiation revealed an AA‐dependent increase in the expression of genes that could potentially compound the effects of AA on cell differentiation. These data suggest that AA may act in the developing brain to stimulate the generation of CNS neurons and glia, thereby assisting in the formation of neural circuits by promoting the acquisition of neuronal synaptic functions. © 2003 Wiley‐Liss, Inc.
Cholinergic modulation of neurofilament expression and neurite outgrowth in chick sensory neurons
Authors: Tata Ada Maria , Cursi Silvia , Biagioni Stefano , Augusti‐Tocco Gabriella
Published: October 2004

The morphogenetic role of the neurotransmitter acetylcholine was studied in cultures of dorsal root ganglia (DRG) neurons obtained from E12 and E18 chick embryos. With this model we have evaluated neurofilament expression and neurite outgrowth following cholinergic agonist and antagonist treatment. Morphometric analysis undertaken to evaluate fiber outgrowth has indicated that E12 DRG cultures treated with cholinergic agonists, such as muscarine and carbachol, when compared with untreated cultures, have longer fibers and a higher number of fibers per neuron. Concomitant treatment with agonists and the antagonists atropine or mecamylamine counteracts the increase in fiber outgrowth, suggesting that the cholinergic agonist effects were mediated by both muscarinic and nicotinic receptors. The expression of the three neurofilament proteins was also evaluated. Western blot analysis showed that, in E12 DRG cultures, both muscarine and carbachol induce a significant increase in neurofilament protein expression and that this effect is inhibited by cholinergic antagonist treatment. Moreover, Northern blot analysis has demonstrated that the increased expression of 68‐ and 145‐kDa neurofilament proteins is dependent on cholinergic modulation of the neurofilament transcripts. Modulated expression of neurofilament proteins by cholinergic agonists was not evident in E18 DRG cultures, suggesting that, when sensory neurons have completed their differentiation, the cholinergic system might be involved in other functions. In conclusion, our data demonstrate that, during sensory neuron development, acetylcholine modulates neurite outgrowth controlling neurospecific marker expression. © 2003 Wiley‐Liss, Inc.
Mechanism of interleukin‐1β‐induced calcitonin gene‐related peptide production from dorsal root ganglion neurons of neonatal rats
Authors: Hou Lingfei , Li Wenjing , Wang Xian
Published: October 2004

Calcitonin gene‐related peptide (CGRP) is synthesized in dorsal root ganglion (DRG) neurons and released from primary afferent neurons to mediate hemodynamic effects and neurogenic inflammation. The effect of the proinflammatory cytokine interleukin‐1 (IL‐1)‐β on CGRP release from these sensory neurons was investigated. The results showed that IL‐1β (1 ng/ml) could directly induce CGRP release following prolonged incubation (24 hr) with these neurons. Treatment with IL‐1β (0.1–1.0 ng/ml) significantly increased CGRP release in a concentration‐dependent manner. In addition, pretreatment of DRG cells with actinomycin D at 1 μM or cyclohexamide at 10 μM for 30 min inhibited 1 ng/ml IL‐1β‐induced CGRP release in DRG neurons of neonatal rats. The inhibitors of PKC, JNK MAPK and NF‐κB, but not p38 or ERK1/2 MAPK, blocked IL‐1β‐induced CGRP release. RNase protection assay showed that IL‐1β could cause α‐CGRP mRNA increase in a time‐ and concentration‐dependent manner, although the level of β‐CGRP mRNA was not affected. These results indicate that IL‐1β may activate PKC, which in turn initiates JNK MAPK and activates NF‐κB and finally induces α‐CGRP gene expression and release from these sensory neurons. © 2003 Wiley‐Liss, Inc.
Intracerebroventricular administration of GABA‐A and GABA‐B receptor antagonists attenuate feeding and sleeping‐like behavior induced by L‐pipecolic acid in neonatal chicks
Authors: Takagi T. , Bungo T. , Tachibana T. , Saito E‐S. , Saito S. , Yamasaki I. , Tomonaga S. , Denbow D.M. , Furuse M.
Published: October 2004

It has been demonstrated that L‐pipecolic acid (L‐PA), a major metabolic intermediate of L‐lysine (L‐Lys) in the mammalian and chicken brain, is involved in the functioning of the GABAergic system. A previous study has shown that intracerebroventricular (i.c.v.) injection of L‐PA suppressed feeding and induced sleep‐like behavior in neonatal chicks; however, the precise relationship between the GABAergic system and L‐PA has not been clarified. In the present study, the role of the GABA‐A or GABA‐B receptors in the suppression of food intake and induction of sleeping‐like behavior by L‐PA was investigated. Chicks were injected i.c.v. with the GABA‐A antagonist picrotoxin or GABA‐B antagonist CGP54626 along with L‐PA. Although suppression of food intake by L‐PA was restored partially by co‐injection with CGP54626, but not picrotoxin, sleep‐like behavior induced by L‐PA was suppressed significantly by both antagonists. These results suggested that L‐PA activated both GABA‐A and GABA‐B receptors, and GABA‐B receptors alone contributed to food intake whereas both receptors contributed to sleep‐like behavior. © 2003 Wiley‐Liss, Inc.
Raman spectroscopy of gerhardtite at 298 and 77 K
Authors: Frost Ray L. , Leverett Peter , Williams Peter A. , Weier Matt L. , Erickson Kristy L.
Published: October 2004

Raman spectroscopy has been used to study the nature of gerhardtite, a naturally occurring basic copper(II) nitrate of formula Cu2NO3(OH)3. Raman spectra at 77 K show four bands at 3557, 3548, 3467 and 3409 cm−1 in accordance with the crystal structure with three non‐equivalent hydroxyl groups. Estimations of hydrogen bond distances of 0.3019, 0.2987, 0.2855 and 0.2804 pm are obtained. Cooling to liquid nitrogen temperatures did not affect these values. Two bands are observed at 1048 and 1052 cm−1 in the NO3 stretching region. Cooling to liquid nitrogen temperature altered the ratio of these nitrates from 3/1 to 1/3. Two sets of bands in the antisymmetric stretching region of the nitrate in the 77 K spectra suggest that there are two non‐equivalent nitrate anions in the gerhardtite structure at liquid nitrogen temperature. X‐ray crystallography suggests three independent oxygens in the one nitrate group. The shift in band positions on obtaining Raman spectra at 298 at 77 K indicates a phase change is occurring for the mineral upon cooling to 77 K. Copyright © 2004 John Wiley & Sons, Ltd.