bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic analysis of the capsid region of astroviruses
Authors: Wang Qiu‐Hong , Kakizawa Junko , Wen Le‐Ying , Shimizu Mitsugu , Nishio Osamu , Fang Zhao‐Yin , Ushijima Hiroshi
Published: August 2002

Eight serotypes of human astroviruses (HAstV‐1 to HAstV‐8) have been described. To date, the entire genomes of HAstV‐1 and HAstV‐2 as well as the ORF2 sequences of HAstV‐1–6 and 8 have been reported. In this study, the ORF2 sequences of seventeen strains of HAstVs originating from different countries were determined, as well as the sequence ORF2 of one porcine astrovirus (PAstV) strain. Afterwards, comparison of the capsid protein precursors encoded by ORF2 of 46 strains of HAstVs, PAstV, and feline astrovirus (FAstV) was carried out. A phylogenetic tree showed eight genogroups of HAstVs that corresponded exactly to the serotypes. HAstV‐3 and 7 were the most closely related, whereas HAstVs, FAstV, and PAstV segregated from each other. Compared to a PAstV, a FAstV is closer to HAstVs. Furthermore, the capsid protein precursors were divided into four regions (after amino acid residues 424, 688, and 776, respectively) based on sequence identity. Region I was the most conserved, and FAstV was very close in identity to HAstVs. Two amino acid motifs in region I were predicted to contain the common antigenic epitopes. Region II was relatively variable. Deletions and insertions were characteristic of region III, and region IV was relatively conserved. To our knowledge, this is the first comparative sequence analysis of the capsid protein precursors of eight serotypes of HAstVs as well as two animal astroviruses (FAstV and PAstV). J. Med. Virol. 64:245–255, 2001. © 2001 Wiley‐Liss, Inc.
Analysis of HIV drug‐resistant quasispecies in plasma, peripheral blood mononuclear cells and viral isolates from treatment‐naive and HAART patients
Authors: Paolucci Stefania , Baldanti Fausto , Campanini Giulia , Zavattoni Maurizio , Cattaneo Ercole , Dossena Luca , Gerna Giuseppe
Published: August 2002

The pattern of HIV‐1 reverse transcriptase and protease mutations conferring resistance to antiretroviral drugs was studied in five treatment‐naive patients and five HIV‐infected patients receiving HAART [two reverse transcriptase inhibitors + one protease inhibitor] for ≥ 1 year. Direct sequencing was performed on plasma HIV RNA, HIV DNA from peripheral blood mononuclear cells (PBMCs), and RNA from viral isolates. In addition, reverse transcriptase and protease PCR products from PBMCs HIV DNA, plasma HIV RNA, and viral isolate RNA were cloned in a plasmid to study the quasispecies distribution of drug‐resistance associated mutations. Direct sequencing of HIV DNA from PBMCs and HIV RNA from plasma and viral isolates did not show the presence of drug resistance associated mutations in both reverse transcriptase and protease of HIV from all five treatment‐naive patients. On the contrary, mutation analysis obtained by cloning plasma HIV RNA and PBMCs DNA showed the presence of drug‐resistance related mutations at a low frequency in both HIV enzymes of four out of five treatment‐naive patients. On the other hand, direct sequencing of plasma HIV RNA showed the presence of several reverse transcriptase and protease mutations in all five treated patients. Mutation analysis performed by cloning PBMCs HIV DNA, and HIV RNA from plasma and viral isolates, revealed additional reverse transcriptase and protease changes compared to direct sequencing of the relevant biological samples. All the additional changes were observed in a minority of clones. In conclusion, the data suggest that less frequent drug‐resistant viral variants not detected by direct sequencing of PBMCs, plasma samples, or viral isolates are present in both treatment‐naive and treatment‐experienced HIV patients. These findings may have important implications in the understanding of the selection process of drug‐resistant variants under drug pressure. J. Med. Virol. 65:207–217, 2001. © 2001 Wiley‐Liss, Inc.
Correlation of hepatitis B virus load with loss of e antigen and emerging drug‐resistant variants during lamivudine therapy
Authors: Zöllner Bernhard , Schäfer Peter , Feucht Heinz‐Hubert , Schröter Matthias , Petersen Jörg , Laufs Rainer
Published: August 2002

It remains unclear whether sequential assessment of hepatitis B virus (HBV) load during lamivudine therapy can predict the loss of hepatitis B e antigen or emergence of drug‐resistant variants. Therefore, a longitudinal study was carried out in 28 consecutive patients with chronic hepatitis B who started lamivudine therapy for a median of 12 months (range, 6–31). HBV DNA copy numbers were determined at 3‐month intervals. From month 6 onward, HBV viral load below the detection limit of the PCR was predictive of the loss of envelope antigen (P = 0.043). Continuously detectable HBV DNA during the first 12 months of treatment indicated emergence of drug‐resistant variants (P = 0.034). These data suggest that the goal of lamivudine therapy should be complete suppression of serum HBV DNA. J. Med. Virol. 65:659–663, 2001. © 2001 Wiley‐Liss, Inc.
GB virus C and TT virus infections in Japanese patients with autoimmune hepatitis
Authors: Nishiguchi Shuhei , Enomoto Masaru , Shiomi Susumu , Obata Noriko , Tanaka Motoharu , Fukuda Katsuhiko , Tamori Akihiro , Habu Daiki , Takeda Tadashi , Tanaka Takashi , Yano Yoshihisa , Otani Shuzo
Published: August 2002

The association of the newly identified viruses, GB virus C (GBV‐C) and TT virus (TTV), with autoimmune hepatitis remains to be elucidated. Sera from 20 Japanese patients with autoimmune hepatitis and 50 volunteer blood donors were assayed for GBV‐C RNA, antibodies to the GBV‐C second envelope protein (E2), and TTV DNA. GBV‐C RNA was examined by reverse‐transcription polymerase chain reaction (PCR). Anti‐GBV‐C E2 (a marker of past infection) was tested by an enzyme‐linked immunosorbent assay. TTV DNA was amplified by PCR using two different sets of primers: one derived from the original N22 sequence (Set A) and the other from the untranslated region (Set B). None of the patients or controls had GBV‐C RNA. Anti‐GBV‐C E2 was found significantly more often in patients with autoimmune hepatitis (3/20) than in controls (1/50; P = 0.034). The prevalence of TTV DNA detected by primers Set A and that detected with either Set A or B were similar among patients with autoimmune hepatitis (4/20 and 16/20, respectively) and controls (9/50 and 40/50, respectively). Clinical characteristics did not differ in association with any of these viral markers. Of the 13 TTV isolates amplified with Set A, seven were classified as genotype 1a, four as genotype 1b, and 2 as genotype 3; no particular strain was associated with autoimmune hepatitis. These findings provide no compelling evidence that GBV‐C or TTV has a pathogenic role in autoimmune hepatitis. J. Med. Virol. 66:258–262, 2002. © 2002 Wiley‐Liss, Inc.
Indirect modelling of the scattering from two‐dimensional composite uniaxial bianisotropic cylinders of arbitrary cross‐sections
Authors: Yin Wen‐Yan , Li Le‐Wei , Leong Mook‐Seng , Yeo Tat‐Soon
Published: August 2002

The indirect modelling of electromagnetic scattering from two‐dimensional composite uniaxial bianisotropic cylinders of arbitrary cross‐section is successfully performed according to the principle of equivolumetric model. The mathematical treatment here is based on the generalized boundary‐value method combined with the technique of separate variables. The solution is obtained from a system of linear equations of infinite order which is then truncated during numerical computations. Then, numerical investigation is carried out to demonstrate hybrid effects of geometrical and constitutive parameters of guest and host cylinders on the co‐ and cross‐polarized echo widths in the far‐field zone. It is shown that under certain circumstances, the indirect modelling technique is very efficient to study the scattering characteristics of many practical complex planar structures, and has some advantages over the direct numerical method. Copyright © 2001 John Wiley & Sons, Ltd.
Leukemia inhibitory factor mRNA expression is upregulated in macrophages and olfactory receptor neurons after target ablation
Authors: Getchell Thomas V. , Shah Dharmen S. , Partin James V. , Subhedar Nishikant K. , Getchell Marilyn L.
Published: August 2002

After target ablation by olfactory bulbectomy (OBX), the murine olfactory epithelium (OE) undergoes degenerative changes leading to apoptosis of olfactory receptor neurons (ORNs) followed by regenerative changes that include proliferation of progenitor cells leading to neurogenesis and ORN replacement. Macrophages recruited to the OE after OBX are involved in both the degenerative and regenerative processes. Relative quantitative RT‐PCR was used to demonstrate that within hours of OBX, mRNAs encoding three key components in the leukemia inhibitory factor (LIF) signaling pathway, including LIF, LIF receptor (LIFR), and STAT3, as well as cyclin D1, a growth factor sensor indicative of progenitor cell transformation, were upregulated. These mRNAs reached peak levels of expression on or before day 3 post‐OBX, coincident with the peak time for macrophage recruitment and progenitor cell proliferation. Cells expressing LIF mRNA in the OE of mice at 3 days post‐OBX, the time point at which LIF mRNA expression peaked, were identified using non‐isotopic in situ hybridization. LIF mRNA was localized in infiltrating macrophages; near‐adjacent sections exhibited macrophages immunoreactive for F4/80, a marker for activated macrophages, in numbers commensurate with those expressing LIF mRNA. LIF mRNA was also localized in surviving ORNs, identified by their expression of olfactory marker protein (OMP) mRNA and protein in near‐adjacent sections. Our data suggest that LIF functions as a mitogen originating from recruited macrophages through an intercellular signaling pathway that stimulates proliferation of progenitor cells leading to neurogenesis and regeneration, and as an intracellular survival factor for traumatized ORNs. © 2002 Wiley‐Liss, Inc.
Effects of IL‐1β, IL‐6 or LIF on rat sensory neurons co‐cultured with fibroblast‐like cells
Authors: Edoff Karin , Jerregård Helena
Published: August 2002

Inflammation may affect the local presence of sensory nerve fibers in situ and inflammatory mediators influence sensory neurons in vitro. In the present study we have investigated effects of the cytokines interleukin‐1β (IL‐1β, interleukin‐6 (IL‐6), and leukemia inhibitory factor (LIF) on survival of and neurite growth from neonatal rat sensory neurons co‐cultured with fibroblast‐like cells prepared from neonatal rat skin (sFLCs) or perichondrium (pFLCs). The results showed that both FLC types expressed receptors for all three cytokines. Five ng/ml of either cytokine, but not lower or higher concentrations, supported survival of DRG neurons co‐cultured with sFLCs. Neuronal survival was also enhanced by addition of the soluble IL‐6 receptor (rsIL‐6R) with or without IL‐6. In co‐cultures with pFLCs neuronal survival was promoted by IL‐6, increasing with cytokine concentration. Addition of rsIL‐6R without IL‐6 did also stimulate neuronal survival. The growth of neurites from DRG neurons co‐cultured with sFLCs was stimulated by 0.5 ng/ml LIF, unaffected by 5 ng/ml LIF and inhibited by 50 ng/ml LIF. Considering DRG neurons co‐cultured with pFLCs, 50 ng/ml of either of the three cytokines, as well as rsIL‐6R conditioned medium, stimulated neurite outgrowth. Some of the cytokine effects observed were reduced by application of antibodies against nerve growth factor (NGF). We conclude that that the cytokines examined affect DRG neurons in terms of survival or neuritogenesis, that the effects are influenced by cytokine concentration and the origin of the FLCs and that some of the effects are indirect, probably being mediated by factors released from FLCs. © 2002 Wiley‐Liss, Inc.
Pre‐ and postsynaptic maturation of the neuromuscular junction during neonatal synapse elimination depends on protein kinase C
Authors: Lanuza Maria A. , Garcia Neus , Santafé Manel , González Carmen M. , Alonso Immaculada , Nelson Phillip G. , Tomàs Josep
Published: August 2002

The distribution of acetylcholine receptors (AChRs) within and around the neuromuscular junction changes dramatically during the first postnatal weeks, a period during which polyneuronal innervation is eliminated. We reported previously that protein kinase C (PKC) activation accelerates postnatal synapse loss. Because of the close relationship between axonal retraction and AChR cluster dispersal, we hypothesize that PKC can modulate morphological maturation changes of the AChR clusters in the postsynaptic membrane during neonatal axonal reduction. We applied substances affecting PKC activity to the neonatal rat levator auris longus muscle in vivo. Muscles were then stained immunohistochemically to detect both AChRs and axons. We found that, during the first postnatal days of normal development, substantial axonal loss preceded the formation of areas in synaptic sites that were free of AChRs, implying that axonal loss could occur independently of changes in AChR cluster organization. Nevertheless, there was a close relationship between axonal loss and AChR organization; PKC modulates both, although differently. Block of PKC activity with calphostin C prevented both AChR loss and axonal loss between postnatal days 4 and 6. PKC may act primarily to influence AChR clusters and not axons, insofar as phorbol ester activation of PKC accelerated changes in receptor aggregates but produced relatively little axon loss. © 2002 Wiley‐Liss, Inc.
Varied actions of proinflammatory cytokines on excitotoxic cell death in the rat central nervous system
Authors: Allan Stuart M.
Published: August 2002

Interleukin (IL)‐1β mediates diverse forms of neurodegeneration and exacerbates cell death induced by striatal injection of the excitotoxin α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) in the rat brain. The objective of this study was to determine whether this effect was specific to IL‐1β. Injection of IL‐1α and AMPA in the striatum had effects identical to those of IL‐1β, whereas coinjection of IL‐6 or tumor necrosis factor (TNF)‐α with AMPA failed to induce significant cortical cell death. In contrast to IL‐1α, IL‐1β, and IL‐6, TNFα significantly reduced (by 38%) the local striatal damage. These findings suggest that the effect of IL‐1 on AMPA receptor‐mediated cell death in the rat striatum is not mimicked by other proinflammatory cytokines. Furthermore, TNFα shows neuroprotective effects against acute excitotoxic injury. © 2002 Wiley‐Liss, Inc.
Participation of structural microtubule‐associated proteins (MAPs) in the development of neuronal polarity
Authors: González‐Billault C. , Engelke M. , Jiménez‐Mateos E.M. , Wandosell F. , Cáceres A. , Avila J.
Published: August 2002

Several lines of evidence have indicated that changes in the structure of neuronal cytoskeleton provide the support for the dramatic morphological changes that occur during neuronal differentiation. It has been proposed that microtubule‐associated proteins can contribute to the development of this phenomenon by controlling the dynamic properties of microtubules. In this report we have characterized the effect of the combined suppression of MAP1B and tau, and MAP1B and MAP2 on neuronal polarization in cultured hippocampal cells grown on a laminin‐containing substrate. We have taken advantage of the use of a mouse line deficient in MAP1B expression obtained by the gene trapping approach. In addition to this engineered mice line we used the antisense oligonucleotide approach to induce the suppression of tau or MAP2, in wild type and MAP1B‐deficient neurons. Together these results show a synergistic role for MAP1B/MAP2 and MAP1B/TAU. © 2002 Wiley‐Liss, Inc.
Cerebrospinal fluid neurofilament and glial fibrillary acidic protein in patients with cerebral vasculitis
Authors: Nylén K. , Karlsson J‐E. , Blomstrand C. , Tarkowski A. , Trysberg E. , Rosengren L.E.
Published: August 2002

Few diseases in clinical medicine cause as much diagnostic consternation as central nervous system (CNS) vasculitis because of its varying modes of presentation and frequently overlapping clinical and pathological features. There are no pathognomonic clinical or laboratory findings. The purpose of the present retrospective study was to validate the use of the light subunit of neurofilament triplet protein (NFL) and glial fibrillary acidic protein (GFAP) as markers of CNS tissue damage for patients with systemic or isolated CNS vasculitis. Levels of cerebrospinal fluid (CSF) NFL and GFAP were measured using ELISAs. Both CSF NFL and CSF GFAP concentrations were significantly higher in a patient group diagnosed with CNS vasculitis (P < 0.01 and P < 0.05, respectively) than in a patient group for whom CNS vasculitis was excluded. In the future, analysis of CSF NFL in particular, but also GFAP, may be a useful complement in the difficult clinical task of diagnosing CNS vasculitis. © 2002 Wiley‐Liss, Inc.
Temporal analysis of cytokine gene expression during infiltration of porcine neuronal grafts implanted into the rat brain
Authors: Melchior Benoît , Rémy Séverine , Nerrière‐Daguin Véronique , Heslan Jean‐Marie , Soulillou Jean‐Paul , Brachet Philippe
Published: August 2002

A large array of evidence supports the involvement of infiltrating T lymphocytes in the rejection process of intracerebral neuronal xenografts. Little is known, however, about the molecular mechanisms that drive the recruitment of this cell type. In the present work, we used real‐time RT‐PCR methodology to investigate the kinetics of cytokine gene expression during the infiltration of fetal porcine neurons (PNEU) implanted into the striatum of LEW.1A rats. T lymphocyte infiltration was followed by measuring the intracerebral levels of transcripts encoding the β chain of the T cell receptor. These transcripts remained barely detectable until the fourth week (28 days) postimplantation, when a sudden accumulation occurred. Their kinetics, which support previous immunohistochemical observations, indicate that αβT lymphocyte recruitment occurs rapidly after a delay of several weeks in this experimental model. Infiltration of PNEU grafts by T lymphocytes was accompanied by a concomitant, dramatic augmentation of transcripts coding for monocyte chemotactic protein‐1 and RANTES (for regulated on activation, normal T cell expressed and secreted), two chemokines targeting this cell type, among others. Likewise, a sudden accumulation of transcripts of proinflammatory lymphokines [interleukin (IL)‐1α, tumor necrosis factor‐α, IL‐6] as well as Th1 cytokines (IL‐2, interferon‐γ) was also detected. In contrast, IL‐4, ‐10, and ‐13 mRNA remained barely detectable at the different time points. No significant changes were noticed for IL‐12 or transforming growth factor‐β transcripts. These data support the concept that T lymphocyte infiltration of PNEU grafts is actively promoted by a local production of chemokines and proinflammatory lymphokines and is based on a Th1 polarization. © 2002 Wiley‐Liss, Inc.
Characterization of astrocytes derived from human NTera‐2/D1 embryonal carcinoma cells
Authors: Sandhu Jagdeep K. , Sikorska Marianna , Walker P. Roy
Published: August 2002

Astrocytes are the predominant cell type in the vicinity of glutamatergic synapses, where they monitor and maintain low levels of glutamate. Synaptic homeostasis of glutamate involves its removal from the synaptic cleft via high‐affinity glutamate transporters, glutamate transporter‐1 (GLT‐1)/excitatory amino acid transporters (EAAT)2 and glutamate and aspartate transporter (GLAST)/EAAT1, and glutamate‐catabolizing enzyme, glutamine synthase. Glutamate transporters have been mostly characterized in rodent astrocytes, due to the lack of a convenient human cell system. We report here that NTera‐2 (NT2/D1, a cell line derived from a human teratocarcinoma and known to differentiate into neurons) can also be differentiated by a 4‐week treatment with retinoic acid into functional astrocytes (NT2/A). Differentiation was accompanied by decreased cell proliferation and cell‐cycle arrest, as measured by flow cytometry, immunostaining for Ki67 and incorporation of 5‐bromo‐2′deoxyuridine (BrdU). Immunocytochemistry and Western blot analysis showed that NT2/A expressed glial fibrillary acidic protein, vimentin and S100β. Reverse transcription polymerase chain reaction (PCR) detected mRNA encoding glutamate transporters GLT‐1/EAAT2 and GLAST/EAAT1. The expression level of GLAST/EAAT1 was higher than that of GLT‐1/EAAT2, which is a typical expression pattern for primary astrocytes. Functionality of the transporters was demonstrated by the uptake of 3H‐glutamate. NT2/A also expressed active glutamine synthase, and treatment with glutamate (up to 1 mM for 24 hr) was non‐toxic, suggesting that these cells were capable of converting it to non‐toxic metabolites. NT2/A and NT2‐derived neurons could be grown as mixed cultures and this may prove to be a useful experimental model to study molecular mechanisms underlying glutamate excitotoxicity. © 2002 Government of Canada. Exclusive worldwide publication rights in the article have been transferred to Wiley‐Liss, Inc.
L‐Serine regulates the activities of microglial cells that express very low level of 3‐phosphoglycerate dehydrogenase, an enzyme for L‐serine biosynthesis
Authors: Sugishita Hiroki , Kuwabara Yasuhide , Toku Kazuko , Doi Lisa , Yang Lihua , Mitoma Junya , Furuya Shigeki , Hirabayashi Yoshio , Maeda Nobuji , Sakanaka Masahiro , Tanaka Junya
Published: August 2002

Microglia are well known to become activated during various kinds of neuropathological events. The factors that are responsible for the activation, however, are not fully determined. In the present study, L‐Ser was shown to enhance production of nitric oxide (NO), interleukin‐6 (IL‐6) and tumor necrosis factor α (TNF α) by lipopolysaccharide (LPS)‐stimulated cultured rat microglial cells. L‐Ser, however, did not enhance the expression of mRNAs encoding inducible NO synthase, IL‐6 and TNF α. On the other hand, astrocytes did not depend on L‐Ser for release of IL‐6 and TNF α. The expression of an enzyme 3‐phosphoglycerate dehydrogenase (3PGDH), which is essential for L‐Ser biosynthesis from a glycolytic intermediate 3‐phosphoglycerate, was investigated. As revealed by Western blotting and immunocytochemical staining, 3PGDH‐protein expression in vitro was the highest in astrocytes, intermediate in neurons and the lowest in microglial cells. Semiquantitative RT‐PCR showed that microglial cells expressed 3PGDH‐mRNA at a lower level than astrocytes. In frozen sections from rat forebrain, only astrocytes were immunoreactive for 3PGDH. The present study suggested that L‐Ser is able to modulate microglial function mainly at the translation level because microglial cells cannot synthesize sufficient amount of L‐Ser due to the scarce expression of 3PGDH. J. Neurosci. Res. 64:392–401, 2001. © 2001 Wiley‐Liss, Inc.
Constitutive expression and delayed light response of casein kinase Iϵ and Iδ mRNAs in the mouse suprachiasmatic nucleus
Authors: Ishida Yoshiki , Yagita Kazuhiro , Fukuyama Tsuyoshi , Nishimura Masataka , Nagano Mamoru , Shigeyoshi Yasufumi , Yamaguchi Shun , Komori Takahide , Okamura Hitoshi
Published: August 2002

Casein kinase Iϵ (CKIϵ) and casein kinase Iδ (CKIδ) phosphorylate clock oscillating mPER proteins, and play a key role in the transcription (post)translation feedback loop that generates circadian rhythm. In the present study, the expression profiles of CKIϵ and CKIδ mRNAs were examined in the mice clock center, suprachiasmatic nucleus (SCN). Moderate levels of CKIϵ and CKIδ mRNAs were constantly expressed in the SCN in both light:dark and constant dark conditions. This finding supports the hypothesis that CKI may form a constant threshold to the nuclear entry of mPER proteins as in the Drosophila homologue, double‐time. Further, we demonstrated that the light exposure at subjective night induced a delayed increase in CKIϵ and CKIδ mRNAs in the SCN. CKIϵ and CKIδ proteins may play a role on light‐induced phase‐shift. J. Neurosci. Res. 64:612–616, 2001. © 2001 Wiley‐Liss, Inc.
Changes in gene expression following induction of ischemic tolerance in rat brain: Detection and verification
Authors: Wrang Maria L. , Møller Flemming , Alsbo Carsten W. , Diemer Nils H.
Published: August 2002

Tolerance against ischemic insults can be elicited in the CA1 region of rat hippocampus by inducing a short ischemic period 2–3 days prior to the ischemic insult. To detect genes whose expression changes following induction of ischemic tolerance (IT), we applied a differential display technique called restriction fragment differential display‐PCR (RFDD‐PCR). RFDD‐PCR displays the coding region of mRNA and allows detection of differentially expressed mRNA. Double‐stranded cDNA generated using a T25V primer is digested by the endonuclease TaqI, and adapters are ligated onto the cDNA fragments. When amplifying the adapter‐containing cDNA fragments under high‐stringency conditions, reproducible PCR profiles are obtained. By comparing these profiles from naïve and ischemia‐tolerant rat brains statistically, significant expression changes of 20 fragments were identified. To verify the observed changes, quantitative PCR and in situ hybridization were performed for three fragments representing proteins with quite different functions (GluR2‐flop, SC1, and p68 RNA helicase). Quantitative PCR displayed the same degree of regulation as RFDD‐PCR, but in situ hybridization did not display any regulation. As the applied PCR‐based techniques detect only polyadenylated mRNA, whereas in situ hybridization detects both nonadenylated and adenylated mRNA, changes in the polyadenylation state of the mRNA, rather than inconsistent changes in the total amount of mRNA, probably explain this discrepancy. Thus, our results show that the expression of genes hitherto not related to IT changes with the induction of IT and that the degree of regulation displayed by RFDD‐PCR can be verified by quantitative PCR. J. Neurosci. Res. 65:54–58, 2001. © 2001 Wiley‐Liss, Inc.
Expression of small heat shock proteins and intermediate filaments in the human optic nerve head astrocytes exposed to elevated hydrostatic pressure in vitro
Authors: Salvador‐Silva Mercedes , Ricard Cynthia S. , Agapova Olga A. , Yang Ping , Hernandez M. Rosario
Published: August 2002

The small heat shock proteins (sHSP), αB‐crystallin and Hsp27 are chaperone molecules that maintain the integrity of intermediate filament (IF) network and prevent unfolding of cellular proteins induced by stress. In the optic nerve head (ONH) of eyes with glaucoma, reactive astrocytes expressed Hsp27, perhaps in response to stress related to elevated intraocular pressure. In this study, we determined the effect of elevated hydrostatic pressure (HP) in the synthesis, distribution and co‐localization of αB‐crystallin and Hsp27 with IF in cultured ONH astrocytes. Astrocyte monolayers were pressurized to 60 mm Hg (92% air 8% CO2) and incubated at 37°C for 6, 24 or 48 hr. Controls were exposed to ambient pressure. Cells were analyzed by immunocytochemistry, Western blot and immunoprecipitation using antibodies to Hsp27, αB‐crystallin, vimentin or GFAP. Control astrocytes seemed flat, polygonal with short processes. αB‐crystallin appeared granular in the perinuclear area and filamentous in the cell periphery. Fine granular Hsp27 was distributed throughout the cytoplasm. GFAP and vimentin co‐localized with Hsp27 in the cytoplasm. Astrocytes exposed to HP were star‐shaped with long processes. Hsp27 was condensed in large granules around the nucleus. GFAP and vimentin co‐localized with Hsp27 and αB‐crystallin in the perinuclear area. Western blot and metabolic labeling detected increased synthesis of Hsp27, GFAP and vimentin but no change in αB‐crystallin. These results indicated that GFAP and vimentin associate with Hsp27 and αB‐crystallin in ONH astrocytes. HP affected the integrity of the cytoskeleton consistent with morphological changes. Small HSP may reinforce and maintain IF integrity in response to HP. J. Neurosci. Res. 66:59–73, 2001. © 2001 Wiley‐Liss, Inc.
Excitation of the pedunculopontine tegmental NMDA receptors induces wakefulness and cortical activation in the rat
Authors: Datta Subimal , Patterson Elissa H. , Spoley Eric E.
Published: August 2002

Microinjection of the excitatory amino acid, L‐glutamate into the brainstem pedunculo pontine tegmentum (PPT) has been shown to induce wakefulness, however, it has been unclear that receptors mediate this effect. The aim of this study was to test the hypothesis that in the PPT, L‐glutamate induces cortical activation and wakefulness via activation of NMDA receptors. To test this hypothesis, three sets of micro‐injections into the PPT were carried out on two different groups of rats that were then allowed to move freely although chronic instrumentation recorded sleep/wake states. Three days after the initial control injections of saline, in a contra‐lateral site, Group I was micro‐injected with saline + glutamate (saline first, and glutamate 15 min later); after another 3 days, the same rats were micro‐injected with the NMDA‐receptor‐specific antagonist, 2‐amino‐5‐phosphonopentanoic acid, (AP5) + glutamate. Group II received the same initial control injections (saline only), then AP5 + glutamate and the saline + glutamate micro‐injections last. In rats that were not pretreated with AP5, microinjection of a 90 ng dose of L‐glutamate (0.48 nmol in a volume of 0.1 μl vehicle) kept animals awake for 2–3 hr by eliminating both slow‐wave sleep (SWS) and rapid eye movement (REM) sleep. These behavioral state changes were accompanied by concomitant increase in the power of gamma (γ) frequency (20–60 Hz) waves in the cortical EEG. Pretreatment of L‐glutamate injection sites with 0.48 nmol of AP5 blocked L‐glutamate‐induced‐wakefulness and preserved a normal amount of wakefulness and sleep. Pretreatment with AP5 decreased the power of γ‐wave activity below its control level. These results support the hypothesis that the glutamate‐induced‐wakefulness and cortical activation effects are mediated via the NMDA receptors. J. Neurosci. Res. 66:109–116, 2001. © 2001 Wiley‐Liss, Inc.
Caspase cleavage of exon 9 deleted presenilin‐1 is an early event in apoptosis induced by calcium ionophore A 23187 in SH‐SY5Y neuroblastoma cells
Authors: Popescu Bogdan O. , Cedazo‐Minguez Angel , Popescu Laurentiu M. , Winblad Bengt , Cowburn Richard F. , Ankarcrona Maria
Published: August 2002

Presenilins (PSs) are mutated in a majority of familial Alzheimer disease (FAD) cases. Mutated PSs may cause FAD by a number of pro‐apoptotic mechanisms, or by regulating γ‐secretase activity, a protease involved in β‐amyloid precursor protein processing to the neurotoxic β‐amyloid peptide. Besides their normal endoproteolytic processing, PSs are substrates for caspases, being cleaved to alternative N‐terminal and C‐terminal fragments. So far little is known about the role of PSs cleavage in the apoptotic machinery. Here, we used SH‐SY5Y neuroblastoma cells stably transfected with wild‐type or exon 9 deleted presenilin 1 (PS1) in a time‐course study after the exposure to the calcium ionophore A23187. During and after exposure to A 23187, intracellular calcium levels were higher in exon 9 deleted PS1 cells as compared with non‐transfected and wild‐type PS1 transfected cells. Cell death and the enrichment of apoptotic cells after A23187 exposure were increased by overexpression of exon 9 deleted PS1 as compared with the control cell lines. Wild‐type PS1 cells were compared with exon 9 deleted PS1 cells and the temporal relationship between PS1 and other caspase substrates cleavages was analyzed. Exon 9 deleted PS1 cells exhibited a higher caspase‐3 activation and a greater cleavage of PS1 and poly(ADP‐ribose) polymerase (PARP) compared with wild‐type PS1 cells. Exon 9 deleted PS1 cleavage occurred earlier than other caspase substrate cleavages (i.e., PARP and gelsolin), simultaneous with minimum detectable caspase‐3 activation. Therefore, alternative cleavage of PS1 may play an important role for the regulation of the proteolytic cascade activated during apoptosis. J. Neurosci. Res. 66:122–134, 2001. © 2001 Wiley‐Liss, Inc.
Induction and axonal localization of epithelial/epidermal fatty acid‐binding protein in retinal ganglion cells are associated with axon development and regeneration
Authors: Allen Gregory W. , Liu Jo‐wen , Kirby Michael A. , De León Marino
Published: August 2002

Epithelial/epidermal fatty acid‐binding protein (E‐FABP) is induced in peripheral neurons during nerve regeneration and is found at high levels in central neurons during neuronal migration and development. Furthermore, E‐FABP expression is required for normal neurite outgrowth in PC12 cells treated with nerve growth factor (NGF). The present study examined whether E‐FABP plays a role in retinal ganglion cell (RGC) differentiation and axon growth. Rat retinal tissues from embryonic (E) and postnatal (P) development through adulthood were examined using immunocytochemical labeling with E‐FABP and growth‐associated protein 43 (GAP‐43) antibodies. E‐FABP colocalized with GAP‐43 at E14 through P10. At E14, E‐FABP immunoreactivity was confined to the somas of GAP‐43‐positive cells in the ganglion cell layer, but it was localized to their axons by E15. The axons in the optic nerve were GAP‐43‐positive and E‐FABP‐negative on E15, but the two proteins were colocalized by E18. Retinal cultures at E15 confirmed that E‐FABP and GAP‐43 colocalize in RGCs. Postnatally, labeling was present between P1 and P10 but decreased at older ages and was minimally present or absent in adult animals. Western immunoblotting revealed that at E18, P1, and P10 E‐FABP levels were at least fourfold greater than those in the adult. By P15, protein levels were only twofold greater, with adult levels reached by P31. Furthermore, E‐FABP could be reinduced during axon regeneration. Dissociated P15 retinal cells cultured in the presence of brain‐derived neurotrophic factor, ciliary neurotrophic factor, and basic fibroblast growth factor exhibited sixfold more GAP‐43 and E‐FABP double‐positive RGCs (cell body and axons) than controls. Moreover, all GAP‐43‐immunoreactive RGCs were also positive for E‐FABP. Taken together, these results indicate the following: 1) E‐FABP is expressed in RGCs as they reached the ganglion cell layer and 2) E‐FABP plays a functional role in the elaboration of RGC axons in both development and regeneration. J. Neurosci. Res. 66:396–405, 2001. © 2001 Wiley‐Liss, Inc.
Neurofilament protein in cerebrospinal fluid: A marker of white matter changes
Authors: Sjögren M. , Blomberg M. , Jonsson M. , Wahlund L.‐O. , Edman Å , Lind K. , Rosengren L. , Blennow K. , Wallin A.
Published: August 2002

The objective of this study was to compare cerebrospinal fluid (CSF) levels of the light subtype of the neurofilament proteins (NFL), tau, and β‐amyloid42 (Aβ42) in individuals with moderate or severe white matter changes (WMC) and in those with mild or no WMC. Twenty‐two patients with Alzheimer's disease (AD), nine patients with subcortical vascular dementia (SVD), and 20 normal controls were included in the study. The occurrence of WMC was evaluated by a neuroradiologist using the Blennow‐Wallin scale. Thirty‐seven subjects had no or only punctate WMC; 14 had moderate to severe WMC. Both diagnostic group and WMC, but not gender or apolipoproteinE E4 inheritance, contributed to the variance in the CSF levels of tau, NFL, and Aβ42. In patients with moderate to severe WMC, CSF NFL (P < 0.01), but not CSF tau or CSF Aβ42, was increased also after correction for age, gender, and degree of cognitive impairment. A comparison between patients and controls with any signs of WMC and those without such signs yielded a similar result: CSF NFL (P < 0.001) was increased in the group with signs of WMC. As in numerous previous studies, we found that CSF tau was increased in AD (P < 0.001) compared with controls. Furthermore, CSF NFL was increased in both AD and SVD compared with controls (P < 0.001 for both). Although diagnostic group seems to be a stronger predictor of the variance found in CSF NFL, a clear association between the presence of WMC and increased CSF NFL was found. Because NFL is located mainly in large myelinated axons, increased CSF NFL in individuals with WMC probably reflects axonal degeneration. J. Neurosci. Res. 66:510–516, 2001. © 2001 Wiley‐Liss, Inc.
International collaboration in organizational behavior research
Authors: Peterson Mark F.
Published: August 2002

The Journal of Organizational Behavior (JOB) has long sought to promote the international exchange of organizational behavior research, particularly between Europeans and North Americans. Cross‐cultural research collaboration, a sizable step past reading research reports written by scholars from nations other than one's own, is becoming an increasing part of international research exchange. The present essay draws from both normative models of international OB methods and descriptive analyses of international collaboration experiences to consider how context affects the process of international collaboration. It draws from theories of transnational management and of sources of influence and meaning to consider pros, cons, and issues in managing alternative forms of international collaboration done for various purposes. Copyright © 2001 John Wiley & Sons, Ltd.
The relationship between monthly and seasonal South‐west England rainfall anomalies and concurrent North Atlantic sea surface temperatures
Authors: Phillips Ian D. , Mcgregor Glenn R.
Published: August 2002

This paper assesses the relationship between a regional index of rainfall (SWER) over Devon and Cornwall, South‐west England, and concurrent gridded (5° × 5°) sea‐surface temperature anomalies (SSTAs) for the North Atlantic–European domain (10–70°N, 80°W–20°E) over the period 1950–97. Monthly and seasonal SSTA : SWER correlation fields are derived, and stepwise regression models are then constructed to specify SWER through SSTA variations. In particular, this paper emphasizes the importance of assessing all correlation matrices for field significance, an analysis stage that is often ignored by many researchers. The most temporally reproducible signal is found between depressed SSTs to the west of the British Isles and above‐average rainfall over Devon and Cornwall, although this eastern Atlantic signal is by no means constant over time in terms of its location and spatial extent. Another distinctive feature of the anomaly correlation maps is for locally significant positive SSTA : SWER associations to emerge at high latitudes (60–70°N) in summer and early autumn, e.g. Davis Strait, Norwegian Sea. Field significance testing reveals that seasonal SSTA : SWER correlation fields are statistically more robust than their monthly counterparts. This is demonstrated by the fact that the seasonal fields (excluding summer) all achieve field significance at the 0.1 level, whereas only five of the 12 monthly fields (January, May, July, October and December) do so, suggesting that some of the locally significant SSTA : SWER correlations presented in this paper could have been obtained by merely correlating SWER with a random number series. Copyright © 2002 Royal Meteorological Society.
Late Holocene (ca. 4 ka) marine and terrestrial environmental change in Reykjarfjördur, north Iceland: climate and/or settlement?
Authors: Andrews John T. , Caseldine Chris , Weiner Nancy J. , Hatton Jackie
Published: August 2002

Core B997‐328PC is from the landward side of a 100‐m‐deep basin in Reykjarfjördur, a small fjord on the north coast of the northwest peninsula of Iceland. This is an area that can be severely affected by incursions of polar sea‐ice but has not suffered marked land erosion during the Settlement period. The core is 422 cm in length and consists principally of fine‐grained muds with in situ molluscs. Eleven AMS 14C dates on molluscs indicate a constant sediment accumulation rate of ca. 1 cm 10 yr−1 for the last 4280 ± 50 yr BP. We measured and derived a variety of proxies for indications of changes in the nearshore environment. These included physical properties and grain size, mass accumulation rates, micropalaeontology (pollen and Foraminifera). Multivariate analysis and constrained clustering were used to define major changes in the proxies. In several parameters the major change in the fjord environment occurred close to 1000 14C yr ago, thus approximately coincident with the onset of the Settlement of Iceland. Other changes are noted at around 1600 and 3400 14C yr ago; Betula pollen disappears from the record ca. 1500 yr BP and there are peaks in marine productivity occurring ca. 2 and 3.4 ka. A major decline in carbonate accumulation and a sharp increase in the cold water benthic foraminifer Elphidium excavatum forma clavata 400 yr ago represents the local marine signature of the Little Ice Age. None of the changes in our data can be explained adequately by a simple call to land‐use practices and an increase in land to sea transport, but both the pollen and foraminiferal records indicate a decrease and even loss of ‘warm’ elements in both flora and fauna over the past 4 kyr. Copyright © 2001 John Wiley & Sons, Ltd.
Moraine development at a small High‐Arctic valley glacier: Rieperbreen, Svalbard
Authors: Lyså Astrid , Lønne Ida
Published: August 2002

Ice‐cored lateral and frontal moraine complexes, formed at the margin of the small, land‐based Rieperbreen glacier, central Svalbard, have been investigated through field observations and interpretations of aerial photographs (1936, 1961 and 1990). The main focus has been on the stratigraphical and dynamic development of these moraines as well as the disintegration processes. The glacier has been wasting down since the ‘Little Ice Age’ (LIA) maximum, and between 1936 and 1990 the glacier surface was lowered by 50–60 m and the front retreated by approximately 900 m. As the glacier wasted, three moraine ridges developed at the front, mainly as melting out of sediments from debris‐rich foliation and debris‐bands formed when the glacier was polythermal, probably during the LIA maximum. The disintegration of the moraines is dominated by wastage of buried ice, sediment gravity‐flows, meltwater activity and some frost weathering. A transverse glacier profile with a northward sloping surface has developed owing to the higher insolation along the south‐facing ice margin. This asymmetric geometry also strongly affects the supraglacial drainage pattern. Lateral moraines have formed along both sides of the glacier, although the insolation aspect of the glacier has resulted in the development of a moraine 60 m high along its northern margin. Copyright © 2001 John Wiley & Sons, Ltd.
Catalytic modification of gallic acid on a silver surface studied by surface‐enhanced Raman spectroscopy
Authors: Alvarez‐Ros M. C. , Sánchez‐Cortés S. , Francioso O. , García‐Ramos J. V.
Published: August 2002

We studied the chemical changes undergone by gallic acid (GA) when adsorbed on a colloidal silver surface by means of surface‐enhanced Raman spectroscopy (SERS). The application of the SERS technique allows a remarkable Raman sensitivity enhancement and the strong fluorescence quenching needed to characterize the highly colored products of GA oxidative condensation. We found that GA can undergo a ring opening, a polymerization of aromatic rings or a combination of both mechanisms, leading to the formation of humic‐like substances. The influence of pH and light irradiation on these catalytic processes was investigated in relation to the importance of these mechanisms. Copyright © 2001 John Wiley & Sons, Ltd.
On the possibility of detecting tetraazatetrahedrane (N4) in liquid or solid nitrogen by Fourier transform Raman spectroscopy
Authors: Östmark Henric , Launila Olli , Wallin Sara , Tryman Rolf
Published: August 2002

The detection limit of N4 (at Td and D2h symmetry) by the Fourier transform (FT) Raman technique was determined in liquid and solid nitrogen using a modified commercial FT‐Raman spectrometer. The detection limit was determined by combining experimental signal strength and noise levels of N2 in liquid and solid nitrogen with ab initio quantum mechanical (QM) calculations of the Raman intensities of N2 and N4 (Td and D2h). The QM calculations were performed at the B3LYP/6–311G(d) level. The detection limit was found to be 34 ppm of N4(Td) in N2(liq) and 80 ppm in N2(solid), using an 8 h measurement time and a laser power of 1000 mW. The paper also reports calculated Raman spectra of N4 (Td and D2h) at the B3LYP/6–311G(d) level and a new harmonic wavenumber scaling factor, s = 0.953447, for nitrogen‐containing molecules at the B3LYP/6–311G(d) level. The Raman spectrum of N4(Td) consists of three lines, at 728.35, 938.93 and 1321.58 cm−1, with Raman scattering activities of 17.5, 36.2 and 30.0 Å4 u−1, respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Differentiation of antique ceramics from the Raman spectra of their coloured glazes and paintings
Authors: Colomban Philippe , Sagon Gérard , Faurel Xavier
Published: August 2002

Two palettes, characteristic of the production of the Sèvres Factory (Manufacture Nationale de Sèvres), and representative of ancient glazing techniques, were studied. One was made with coloured glazes/enamels on Bisque (1050 °C) and the other one was composed of Moufle (880 °C) painting colours. Spectra specific to the white (opacifiers), yellow (including Naples yellow), green, pink, ‘brown–red’ and black coatings/paintings were considered. Emphasis was placed on the different Raman peaks arising from coloured coatings specific to ancient artefacts: greens obtained with dissolved Cu ions or from chromium pigments (Victoria green garnets), Naples yellows (Pb2Sb2O7 pyrochlore), green and black spinels and pink sphene. Attention was paid to the effect of pigment grain size on the Raman spectrum. To illustrate the capability of the method, we analysed some old artefacts from the eighteenth and nineteenth centuries. Copyright © 2001 John Wiley & Sons, Ltd.
Single‐crystal Raman studies on nickel iodate dihydrate, Ni(IO3)2·2H2O
Authors: Schellenschläger V. , Pracht G. , Lutz H. D.
Published: August 2002

Single‐crystal Raman spectra in the range 4000–35 cm−1 and the results of group theoretical treatment including Cartesian symmetry coordinates of nickel iodate dihydrate, Ni(IO3)2 · 2H2O, (space group Pbca, Z = 4) are presented and discussed with respect to the strength of the HO—HOIO3 hydrogen bonds and the extent of intramolecular (intraionic) coupling of the stretching vibrations of both the hydrate H2O molecules and the iodate IO3− ions. The energies and relative intensities of the IO stretching modes in the various species of the unit‐cell group D2h reveal that the iodate ions of the title compound behave as if they possess pseudo C2v site symmetry with a at least partly uncoupled IO stretch due to the significantly shortest (175.5 pm) IO arm and a symmetric (νs) and an antisymmetric stretching vibration (νas) due to the remaining IO2 group (rI–O = 184.2 and 186.0 pm). The respective site‐group modes decrease in the order ν3a ↔ νIO(1) (mean value of the respective unit‐cell group modes: 804 cm−1) > ν1 ↔ νs (772 cm−1) > ν3b ↔ νas (744 cm−1) (ν1 and ν3 as for distorted C3v IO3− ions). For the IO3− bending modes (430–300 cm−1) and the lattice modes below 300 cm−1 the true vibrational modes are not known. The normally used assignment to a symmetric (ν2) and an asymmetric bending vibration (ν4) as for C3v IO3− ions is at least questionable. The hydrogen‐bond distances calculated from the wavenumbers of the OD stretching modes of matrix‐isolated HDO molecules do not fully agree with the data of a neutron diffraction study performed in 1972. Copyright © 2001 John Wiley & Sons, Ltd.