bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of magnetic resonance to animal models of cerebral ischemia
Authors: Hoehn Mathias , Nicolay Klaas , Franke Claudia , van der Sanden Boudewijn
Published: August 2002

The present review has been compiled to highlight the role of magnetic resonance imaging (MRI) and MR spectroscopy (MRS) for the investigation of cerebral ischemia in the animal experimental field of basic research. We have focused on stroke investigations analyzing the pathomechanisms of the disease evolution and on new advances in both nuclear MR (NMR) methodology or genetic engineering of transgenic animals for the study of complex molecular relationships and causes of the disease. Furthermore, we have tried to include metabolic and genetic aspects, as well as the application of functional imaging, for the investigation of the disturbance or restitution of functional brain activation under pathological conditions as relates to controlled animal experiments. J. Magn. Reson. Imaging 2001;14:491–509. © 2001 Wiley‐Liss, Inc.
MRI measurement of wall shear stress vectors in bifurcation models and comparison with CFD predictions
Authors: Köhler Uwe , Marshall Ian , Robertson Malcolm B. , Long Quan , Xu X. Yun , Hoskins Peter R.
Published: August 2002

Steady fluid flow was studied in a simple bifurcation model and in a physiologically realistic model of the human carotid bifurcation. Wall shear stress (WSS) vectors were calculated from phase‐contrast (PC) magnetic resonance imaging (MRI) measurements of the velocity field. Velocity measurements in the inflow regions were also used as boundary conditions for computational fluid dynamics (CFD) calculations of WSS, which were compared with those derived from MRI alone. In regions of well‐behaved flow, MRI and CFD estimates of WSS were in good general agreement. In regions of disturbed flow, for example near the bifurcation, the quality of the MRI measurements was sufficient for reliable calculation of WSS vectors when a sensitive surface coil was used. The combination of MRI and CFD would seem to be a powerful technique for the investigation of flow phenomena. J. Magn. Reson. Imaging 2001;14:563–573. © 2001 Wiley‐Liss, Inc.
Sequence analysis of hepatitis C virus isolated from a fulminant hepatitis patient*
Authors: Kato Takanobu , Furusaka Akihiro , Miyamoto Michiko , Date Tomoko , Yasui Kotaro , Hiramoto Jun , Nagayama Kazuo , Tanaka Teruji , Wakita Takaji
Published: August 2002

Although hepatitis C virus (HCV) is a major cause of non‐A non‐B hepatitis, its pathogenic role in fulminant hepatitis remains controversial. A 32‐year‐old man contracted hepatitis. Serum ALT concentration was reached to 6,970 IU/L, the lowest prothrombin time value was 16% and jaundice and stage II encephalopathy were developed. HCV RNA was detected in this patient by reverse transcription polymerase chain reaction in sera at the acute phase, and it was undetectable during the remission phase when anti‐HCV was found. The entire genome of infected HCV was recovered, cloned, and sequenced from this patient, and compared with the clones of six other chronic hepatitis patients. Phylogenetic analysis revealed a clustering around genotype 2a and a deviation from the other 2a chronic hepatitis strains. Calculating the genetic distance in each subgenomic region revealed that the 5′untranslated region (5′UTR), core, nonstructural (NS) 3, and NS5A were severely deviated. Of 20 clones of the hypervariable region (HVR), 17 showed an identical sequence with the others showing a difference of only one amino acid. HCV was isolated from a fulminant hepatitis patient and its entire genome was recovered; a clustering around genotype 2a was observed, but the sequence deviated especially in 5′UTR, core, NS3, and NS5A; and monoclonality of the HVR sequence was found not only in the fulminant hepatitis patient but in a certain percentage of chronic hepatitis patients. J. Med. Virol. 64:334–339, 2001. © 2001 Wiley‐Liss, Inc.
Detection of measles virus genome in lymphocytes from asymptomatic healthy children
Authors: Sonoda Satomi , Nakayama Tetsuo
Published: August 2002

A total of 342 samples of peripheral blood mononuclear cells (PBMC) were obtained from 145 healthy individuals, which we examined for the presence of measles virus genome RNA by reverse transcription‐polymerase chain reaction (RT‐PCR), to identify whether asymptomatic infection of measles virus has occurred in healthy children. Measles virus genome was detected in 11 (23.4%) of 47 nonimmunized individuals; all positives for RT‐PCR were infants who experienced measles exposure. No genome was detected in those without measles exposure. In 83 individuals immunized with measles vaccine, the vaccine strain genome was detected in 10 (71.4%) of 14 recipients whose PBMC were obtained within 2 months of vaccination. Measles wild‐type genome was detected in 36 (46.2%) of 78 individuals, 40 (25.2%) of 159 samples, who had been immunized more than 2 months before. The wild‐type measles genome was also detected in 6 (46.2%) of 13 individuals who had been infected with measles in the distant past. The measles PCR‐positive rate was not related to the period since immunization or natural infection. Sequence analysis of PCR products demonstrated they were all in the same cluster of D5 lineage, which was the circulating strain during the study period. We obtained 13 samples of nasopharyngeal secretion (NPS) simultaneously from individuals whose PBMC were positive for measles PCR but did not detect virus genome. Measles genome was, however, detected from NPS in cases of acute infection. We conclude that asymptomatic measles infection is common but would rarely become a source of transmission because of negative PCR in NPS. J. Med. Virol. 65:381–387, 2001. © 2001 Wiley‐Liss, Inc.
Molecular epidemiology of molluscum contagiosum virus and analysis of the host‐serum antibody response in Spanish HIV‐negative patients
Authors: Agromayor Monica , Ortiz Pablo , Lopez‐Estebaranz Jose L. , Gonzalez‐Nicolas Josefa , Esteban Mariano , Martin‐Gallardo Antonia
Published: August 2002

Molluscum contagiosum virus (MCV) lesions from Spanish human immunodeficiency virus (HIV)‐negative patients were clinically examined and analyzed for virus detection and typing. In a study of 147 patients, 97 (66%) were children under 10 years, of whom 49% had atopic dermatitis. MCV lesions were morphologically indistinguishable among the different age groups, but atopic patients presented larger lesions compared with patients without the disorder. In adults, lesions were observed mainly on the genitals. MCVI was the predominant subtype. The deduced MCVI/MCVII ratio (146:1) was much higher than that found in other geographical areas. Protein preparations of the virus‐induced lesions were immunoblotted with sera from 25 MCVI patients. The host‐serum antibody response was weak and variable, although no significant differences were found between atopic and nonatopic patients. Three immunoreactive proteins of 74/80, 60, and 35 kDa were detected in almost all the analyzed sera. The 35 and 74/80‐kDa proteins were virus specific, whereas the 60‐kDa protein band was composed of a mix of human keratins. Immunoblotting of MCV lesions and vaccinia virus‐infected cell extracts with either MCV patient serum or a rabbit antiserum against vaccinia virus showed no cross‐reactivity of these two human poxviruses at the antigenic level. J. Med. Virol. 66:151–158, 2002. © 2002 Wiley‐Liss, Inc.
Clinical and immunological efficacy of intradermal vaccine plus lamivudine with or without interleukin‐2 in patients with chronic hepatitis B
Authors: Dahmen Anja , Herzog‐Hauff Sabine , Böcher Wulf O. , Galle Peter R. , Löhr Hanns F.
Published: August 2002

To evaluate therapeutic immunostimulation nine chronic hepatitis B patients received six monthly intradermal vaccinations with HBsAg in combination with daily lamivudine. Another five patients received six doses of the vaccine and daily lamivudine together with daily Interleukin‐2 (IL‐2) s.c. within 3 months in an open‐labeled trial. Clinical efficacy was assessed by alanine transaminase levels and HBV serology. The induction of specific T and B cell responses was analyzed serially by 3H‐thymidine uptake, ELISA and ELISPOT assays. After the therapy was stopped, seven of nine vaccine/lamivudine and two of five vaccine/lamivudine/IL‐2 recipients did not have detectable HBV DNA. Four complete responders cleared the virus and had normalized ALT levels, however, one of these patients showed transient disease reactivation followed by spontaneous viral clearance and normal ALT five months later. Low frequencies of anti‐HBs producing B cells and HBV specific T helper cells secreting predominantly interferon‐γ were induced by i.d. vaccine therapy. The ELISPOT technique demonstrated transient induction of HBV peptide specific cytotoxic T cells in seven HLA‐A2 positive chronic HBV carriers. The preliminary data from this study demonstrate that the HBV surface antigen vaccine in combination with antiviral or immunomodulating drugs induced antiviral immune responses and consequently viral elimination may be achieved in patients with unfavorable prognosis. J. Med. Virol. 66:452–460, 2002. © 2002 Wiley‐Liss, Inc.
Sequence diversity of human caliciviruses recovered from children with diarrhea in mendoza, Argentina, 1995–1998
Authors: Martínez Norma , Espul Carlos , Cuello Hector , Zhong Weiming , Jiang Xi , Matson David O.
Published: August 2002

Human caliciviruses were detected by EIA and/or RT‐PCR in stool specimens from children with diarrhea treated at out‐ or in‐patient facilities between 1995 and 1998 in Mendoza, Argentina. Mexico virus–like strains detected by primers NV36/51 were transiently prevalent in 1995/1996. Significantly more human caliciviruses were detected when primers were designed from contemporaneously circulating strains. Nucleotide sequences of a highly conserved region in the RNA polymerase gene of 10 selected human caliciviruses were determined. Eight strains were Norwalk‐like viruses and two strains were Sapporo‐like viruses. Seven of the eight Norwalk‐like viruses also were positive by the recombinant Mexico virus antigen EIA. The seven Mexico virus EIA‐positive strains revealed two patterns in the RNA polymerase sequences: two strains were closest to Mexico virus and the other five strains were closest to Lordsdale virus. One of the five “Lordsdale” viruses was found to be a naturally occurring recombinant between the Mexico virus and Lordsdale human calicivirus genetic clusters [Jiang et al., (1999b) Archives of Virology 144:2377–2387]. The Mexico virus EIA‐negative strain had 73–77% nucleotide identity with the closest related Norwalk‐like viruses, indicating it might belong to a new genetic cluster of the Norwalk‐like virus genus. The two Sapporo‐like viruses were distinct genetically; one belonged to the Houston/90 or Parkville cluster and the other to a new cluster. Some strains appeared to have short periods of prevalence and locally adapted primer pairs significantly increased detection rates. The finding of high diversity of circulating strains, including recombinant strains and strains with previously unrecognized genetic identities, highlights a need for studies of human caliciviruses in these children and other populations. J. Med. Virol. 67:289–298, 2002. © 2002 Wiley‐Liss, Inc.
Aluminum, NO, and nerve growth factor neurotoxicity in cholinergic neurons
Authors: Szutowicz Andrzej
Published: August 2002

Several neurotoxic compounds, including Al, NO, and β‐amyloid may contribute to the impairment or loss of brain cholinergic neurons in the course of various neurodegenerative diseases. Genotype and phenotypic modifications of cholinergic neurons may determine their variable functional competency and susceptibility to reported neurotoxic insults. Hybrid, immortalized SN56 cholinergic cells from mouse septum may serve as a model for in vitro cholinotoxicity studies. Differentiation by various combinations of cAMP, retinoic acid, and nerve growth factor may provide cells of different morphologic maturity as well as activities of acetylcholine and acetyl‐CoA metabolism. In general, differentiated cells appear to be more susceptible to neurotoxic signals than the non‐differentiated ones, as evidenced by loss of sprouting and connectivity, decreases in choline acetyltransferase and pyruvate dehydrogenase activities, disturbances in acetyl‐CoA compartmentation and metabolism, insufficient or excessive acetylcholine release, as well as increased expression of apoptosis markers. Each neurotoxin impaired both acetylcholine and acetyl‐CoA metabolism of these cells. Activation of p75 or trkA receptors made either acetyl‐CoA or cholinergic metabolism more susceptible to neurotoxic influences, respectively. Neurotoxins aggravated detrimental effects of each other, particularly in differentiated cells. Thus brain cholinergic neurons might display a differential susceptibility to Al and other neurotoxins depending on their genotype or phenotype‐dependent variability of the cholinergic and acetyl‐CoA metabolism. © 2001 Wiley‐Liss, Inc.
Osteopontin: A novel axon‐regulated Schwann cell gene
Authors: Jander Sebastian , Bussini Simona , Neuen‐Jacob Eva , Bosse Frank , Menge Til , Müller Hans‐Werner , Stoll Guido
Published: August 2002

Osteopontin (OPN) is a RGD‐containing glycoprotein with cytokine‐like, chemotactic, and pro‐adhesive properties. During wound healing, OPN is abundantly expressed by infiltrating macrophages and has been implicated in posttraumatic tissue repair. To delineate a role in the regenerative response to axotomy we examined the expression of OPN in Wallerian degeneration of the sciatic nerve in rats. Unexpectedly, we found high constitutive expression of OPN by myelinating Schwann cells (SCs) in uninjured control nerves. OPN mRNA expression was confirmed in primary cultures of rat SCs. Upon axotomy, SC‐expressed OPN in the degenerating distal nerve stump transiently increased during the first days after injury, but was continuously downregulated thereafter, reaching its minimum at Day 14. Macrophages invading axotomized nerves were OPN‐negative. During late stages after axotomy, SC‐OPN was reexpressed in regenerating but not permanently transected nerves. We also found OPN expression by myelinating SCs in human sural nerves with a dramatic reduction in severe axonal polyneuropathies. Taken together, our study identifies OPN as a novel Schwann cell gene regulated by axon‐derived signals. The lack of OPN induction in infiltrating macrophages indicates fundamental differences in tissue repair between axonal injury in the peripheral nervous system and structural lesions in other organ systems. © 2002 Wiley‐Liss, Inc.
Loss of stimulatory effect of guanosine triphosphate on [35S]GTPγS binding correlates with Alzheimer's disease neurofibrillary pathology in entorhinal cortex and CA1 hippocampal subfield
Authors: García‐Jiménez A. , Cowburn R.F. , Ohm T.G. , Lasn H. , Winblad B. , Bogdanovic N. , Fastbom J.
Published: August 2002

Heterotrimeric guanosine triphosphate (GTP)‐binding proteins (G‐proteins) couple many different cell surface receptor types to intracellular effector mechanisms. Uncoupling between receptors and G‐proteins and between G‐proteins and adenylyl cyclase (AC) and phospholipase C (PLC) has been described for Alzheimer's disease (AD) brain. However, there is little information on whether altered G‐protein signaling in AD is just an end‐stage phenomenon or is important for the progression of disease pathology. Here we used [35S]GTPγS autoradiography to study G‐protein distribution in sections of entorhinal cortex and hippocampus from 23 cases staged for neurofibrillary changes and amyloid deposits according to Braak and Braak (Acta Neuropathol. [1991] 82:239–259). We also studied the effects of GTP, which has been found to increase [35S]GTPγS binding in an Mg2+‐dependent manner. Results show that the ability of GTP (3 μM) to stimulate [35S]GTPγS binding declined significantly with staging for neurofibrillary changes in the entorhinal cortex (P < 0.05, ANOVA) and CA1 subfield of the hippocampus (P < 0.05, ANOVA). No significant changes were seen for [35S]GTPγS binding in the absence of GTP. Our results suggest a decrease in G‐protein GTP hydrolysis, which correlates with the progression of AD neurofibrillary changes, in the regions most affected by this pathology. These alterations appear to occur prior to stages corresponding to clinical disease and could lead to an impaired regulation of several signaling systems in AD brain. © 2002 Wiley‐Liss, Inc.
Neuroprotective actions of selegiline
Authors: Ebadi M. , Sharma S. , Shavali S. , El Refaey H.
Published: August 2002

Selegiline, a selective inhibitor of monoamine oxidase‐B (MAO‐B), was one of the first adjunct therapies in clinical neurology. A retrospective analysis of data from patients with Parkinson's disease found a significant increase in survival in those treated with selegiline plus L‐dopa compared with L‐dopa alone. The mechanism of action of selegiline is complex and cannot be explained solely by its MAO‐B inhibitory action. Pretreatment with selegiline can protect neurons against a variety of neurotoxins, such as 1‐methyl‐4‐phenyl‐1,2,3,6 tetrahydropyridine (MPTP), 6‐hydroxydopamine, N‐(2‐chloroethyl)‐N‐ethyl‐2‐bromobenzylamine (DSP‐4), methyl‐β‐acetoxyethyl‐2‐chloroethylamine (AF64A), and 5,6‐dihydroxyserotonin, which damage dopaminergic, adrenergic, cholinergic, and sertoninergic neurons, respectively. Selegiline produces an amphetamine‐like effect, enhances the release of dopamine, and blocks the reuptake of dopamine. It stimulates gene expression of L‐aromatic amino acid decarboxylase, increases striatal phenylethylamine levels, and activates dopamine receptors. Selegiline reduces the production of oxidative radicals, up‐regulates superoxide dismutase and catalase, and suppresses nonenzymatic and iron‐catalyzed autooxidation of dopamine. Selegiline compensates for loss of target‐derived trophic support, delays apoptosis in serum‐deprived cells, and blocks apoptosis‐related fall in the mitochondrial membrane potential. Most of the aforementioned properties occur independently of selegiline's efficacy to inhibit MAO‐B. © 2002 Wiley‐Liss, Inc.
Long‐term fate of human telencephalic progenitor cells grafted into the adult mouse brain: Effects of previous amplification in vitro
Authors: Buchet Delphine , Buc‐Caron Marie‐Hélène , Sabaté Olivier , Lachapelle François , Mallet Jacques
Published: August 2002

We assessed the developmental potential of human telencephalic progenitor cells, with and without previous amplification in vitro, following grafting into the nonlesioned adult mouse CNS. Cell suspensions, shown to contain neuroepithelium‐like and neuroblast‐like cells, were injected into the subventricular zone (SVZ) and the striatum. These two regions were selected for comparative studies because one, the SVZ, is mitotically active, whereas the other, the striatum, is mitotically inactive. In situ hybridization with a human‐specific Alu probe showed that the cells survived for up to 30 weeks in both targets and migrated away from the injection site. Fresh cells continued to proliferate and gave rise to very extended grafts before differentiating into neurons and glia. We further show that, when grown in vitro prior to grafting, human cells acquired new properties: Their proliferation was very limited, and they differentiated more rapidly. This study therefore provides new information about the use of these cells, which are a potential tool for both cellular and gene therapy. © 2002 Wiley‐Liss, Inc.
Differential enhancement of dialysate serotonin levels in distinct brain regions of the awake rat by modafinil: Possible relevance for wakefulness and depression
Authors: Ferraro Luca , Fuxe Kjell , Tanganelli Sergio , Tomasini Maria Cristina , Rambert Francis A. , Antonelli Tiziana
Published: August 2002

The present in vivo microdialysis study evaluates the possible existence of a differential regulation of serotonergic transmission by the antinarcoleptic drug modafinil [(diphenyl‐methyl)‐sulfinyl‐2‐acetamide; Modiodal] among various brain regions of the awake rat. The results show that, in the cerebral cortex, the central amygdala, and the dorsal raphe nucleus, modafinil in the dose range of 10–100 mg/kg i.p. dose‐dependently increases dialysate serotonin (5‐HT) levels. In other brain areas, such as the medial preoptic area and the posterior hypothalamus, the modafinil‐induced increase in dialysate 5‐HT levels is observed only at tenfold higher doses (100 mg/kg), 10–30 mg/kg being ineffective. Together these data suggest that, in the frontal cortex, the amygdala, and the dorsal raphe, modafinil is more potent in enhancing extracellular 5‐HT levels and presumably 5‐HT transmission than in the medial preoptic area and the posterior hypothalamus. In view of the role of ascending 5‐HT pathways in arousal and depression, it seems likely that the antinarcoleptic drug modafinil may also have an antidepressant potential in addition to its wakefulness‐promoting action, both actions involving enhancement of 5‐HT neurotransmission. © 2002 Wiley‐Liss, Inc.
Cytokine activity contributes to induction of inflammatory cytokine mRNAs in spinal cord following contusion
Authors: Pan Jonathan Z. , Ni Li , Sodhi Ajeet , Aguanno Ann , Young Wise , Hart Ronald P.
Published: August 2002

Injury of the spinal cord leads to an inflammatory tissue response, probably mediated in part by cytokines. Because a common therapy for acute spinal cord injury is the use of an antiinflammatory synthetic glucocorticoid (methylprednisolone), we sought to determine mechanisms contributing to inflammation shortly after acute injury. Cytokine mRNAs [interleukin (IL)‐1α, IL‐1β, tumor necrosis factor (TNF)‐α, and IL‐6] were increased during the first 2 hr following weight‐drop compression injury by RNase protection assay, prior to the reported appearance of circulating lymphocytes. This immediate pattern of cytokine mRNA induction could be replicated in cultured, explanted spinal cord slices but not in whole blood of injured animals, which is consistent with a tissue source of cytokine mRNAs. Western blotting detected IL‐1β‐like immunoreactivity released into culture medium following explantation and pro‐IL‐1β‐like immunoreactivity in freshly dissected spinal cord tissue. Pharmacologically blocking IL‐1 and TNF‐α receptors significantly reduced expression of IL‐1α, IL‐1β, and TNF‐α mRNAs. Finally, mice lacking both IL‐1 and TNF‐α receptors exhibited diminished induction of TNF‐α, IL‐6, and IL‐1ra mRNAs following injury. Therefore, we conclude that contusion injury induces an immediate release of cytokines, which then contributes to the induction of cytokine mRNAs. © 2002 Wiley‐Liss, Inc.
Effects of somatosensory cortical stimulation on expression of c‐Fos in rat medullary dorsal horn in response to formalin‐induced noxious stimulation
Authors: Gojyo Fusami , Sugiyo Shinichi , Kuroda Ryotaro , Kawabata Atsufumi , Varathan Vidya , Shigenaga Yoshio , Takemura Motohide
Published: August 2002

We examined the effects of epidural electrical stimulation of primary (SI) and secondary (SII) somatosensory cortex on expression of c‐Fos protein in rat medullary dorsal horn neurons (Vc; trigeminal nucleus caudalis) in response to formalin‐induced noxious stimulation. Epidural electrical stimulation (single pulse, 0.2 msec duration at 10 Hz) was applied to the left facial region SI or SII at three different stimulus intensities, 0.1, 0.5, and 1.0 mA for 60 min 0 or 2 hr after bilateral injection of formalin into the lower lip. SII stimulation at 1.0 mA immediately after injection of formalin, significantly decreased the number of Fos‐positive cells in the right VcI/II by 32.4%. There was no significant change in the number of Fos‐positive cells in the VcIII/IV. SII stimulation at 0.5 and 1.0 mA 2 hr after injection of formalin, significantly decreased the number of Fos‐positive cells in the right VcI/II by 47.9% and 40.8%, but significantly increased the number of Fos‐positive cells in the right VcIII/IV by 178.8% and 324.3%, respectively. In contrast, SI stimulation had no effect on expression of c‐Fos in Vc. Possible direct corticotrigeminal projections were labeled anterogradely by injection of WGA‐HRP into the SI and SII. In the Vc, labeled terminals were distributed mostly in the contralateral medial half of VcIII/IV and medullary reticular nucleus dorsalis but rarely in VcI/II. These results suggest that activation of SII‐medullary fibers suppress nociceptive information from the oro‐facial regions. © 2002 Wiley‐Liss, Inc.
Elevated vulnerability to oxidative stress‐induced cell death and activation of caspase‐3 by the Swedish amyloid precursor protein mutation
Authors: Eckert Anne , Steiner Barbara , Marques Celio , Leutz Steffen , Romig Helmut , Haass Christian , Müller Walter E.
Published: August 2002

The Swedish double mutation (KM670/671NL) of amyloid precursor protein (APPsw) is associated with early‐onset familial Alzheimer's disease (FAD) and results in from three‐ to sixfold increased β‐amyloid production. The goal of the present study was to elucidate the effects of APPsw on mechanisms of apoptotic cell death. Therefore, PC12 cells were stably transfected with human APPsw. Here we report that the vulnerability of APPsw‐bearing PC12 cells to undergo apoptotic cell death was significantly enhanced after exposure to hydrogen peroxide compared to human wild‐type APP‐bearing cells, empty vector‐transfected cells, and parent untransfected cells. In addition, we have analyzed the potential influence of several mechanisms that can interfere with the execution of the apoptotic cell death program: the inhibition of cell death by the use of caspase inhibitors and the reduction of oxidative stress by the use of (±)‐α‐tocopherol (vitamin E). Interestingly, oxidative stress‐induced cell death was significantly attenuated in APPsw PC12 cells by pretreatment with caspase‐3 inhibitors but not with caspase‐1 inhibitors. In parallel, caspase‐3 activity was markedly elevated in APPsw PC12 after stimulation with hydrogen peroxide for 6 hr, whereas caspase‐1 activity was unaltered. In addition, oxidative stress‐induced cell death could be reduced after pretreatment of APPsw cells with (±)‐α‐tocopherol. The protective potency of (±)‐α‐tocopherol was even greater than that of caspase‐3 inhibitors. Our findings further emphasize the role of mutations in the amyloid precursor protein in apoptotic cell death and may provide the fundamental basis for further efforts to elucidate the underlying processes caused by FAD‐related mutations. J. Neurosci. Res. 64:183–192, 2001. © 2001 Wiley‐Liss, Inc.
Neurofilaments of Klotho, the mutant mouse prematurely displaying symptoms resembling human aging
Authors: Uchida Atsuko , Komiya Yoshiaki , Tashiro Tomoko , Yorifuji Hiroshi , Kishimoto Takeo , Nabeshima Yohichi , Hisanaga Shin‐ichi
Published: August 2002

We reported previously that neurofilaments (NFs) of aged rats were highly packed in the axon and contained a smaller amount of NF‐M as compared with those of young rats (Uchida et al. [1999] J. Neurosci. Res. 58:337–348). We studied NFs of the mutant mouse, named Klotho, which displays prematurely symptoms resembling human aging. The transport of axonal cytoskeletal proteins, including NFs, tubulin and actin, was decreased at the leading portion of the peak of transported proteins in Klotho during the process of premature aging. The nearest neighbor inter‐NF distance in Klotho axons (35–39 nm) was shorter than that of the wild‐type mouse (48–49 nm), indicating the packing of NFs in Klotho. The ratio of NF‐M to NF‐L was slightly decreased in cytoskeletons from the spinal cords of Klotho. These changes are similar, though not identical, to those observed in aged rats, and are the first evidence of age‐related changes in the neurons of Klotho. J. Neurosci. Res. 64:364–370, 2001. © 2001 Wiley‐Liss, Inc.
A subpopulation of nervus terminalis neurons projects to the olfactory mucosa in Xenopus laevis
Authors: Koza Joseph M. , Wirsig‐Wiechmann Celeste R.
Published: August 2002

Biocytin application to the normal or zinc sulfate‐treated nasal cavity of Xenopus laevis was used to trace retrogradely neurons associated with the terminal nerve (TN). Immunocytochemistry was conducted to identify the relationship of gonadotropin‐releasing hormone‐immunoreactive (GnRH‐ir) TN neurons with biocytin‐labeled neurons. Neurons that accumulated biocytin were located in olfactory nerve fascicles close to the olfactory mucosa lining the caudal, medial, and rostral walls of the principal cavity. GnRH‐ir fibers were observed only in the olfactory nerve fascicle projecting to the rostral edge of the principal cavity. In addition, GnRH‐ir fibers did not contact biocytin‐labeled TN neurons. We hypothesize that these two classes of neurons represent separate components of the TN. J. Neurosci. Res. 66:8–15, 2001. © 2001 Wiley‐Liss, Inc.
Effect of liposomes containing cerebroside and cerebroside sulfate on cytoskeleton of cultured oligodendrocytes
Authors: Boggs Joan M. , Wang Huimin
Published: August 2002

Oligodendrocytes (OLs) and the myelin produced by them are enriched in two glycosphingolipids, galactosylceramide (GalC) and its sulfated form, cerebroside sulfate (CBS). We showed earlier that these two glycolipids in opposed liposomal membranes or in methanol solution can adhere to each other. Here we have examined the potential effect of an interaction between GalC/CBS in apposed membranes of oligodendrocytes (OLs) by incubating cultured OLs with GalC/CBS‐containing liposomes and observing the effect on the membrane sheets produced by OLs and on the distribution of OL constituents using fluorescent antibodies and confocal microscopy. The GalC/CBS‐containing liposomes caused redistribution or a decrease in the density of anti‐GalC and anti‐MBP staining but had no effect on the density or distribution of staining by anti‐PI(4,5)P2 that remained uniformly distributed in the membrane sheets. There was no apparent change in the area of the membrane sheets nor in the amount of MBP in OL membranes, as determined by slot blots. In addition, the GalC/CBS‐containing liposomes caused depolymerization of microtubules and actin filaments suggesting that the interaction of GSL‐containing liposomes with the extracellular surface of the OL caused transmission of a signal across the membrane. Because these two glycolipids can adhere to each other across apposed membranes, the liposomal glycolipids may be interacting with a GalC/CBS‐enriched signaling domain in the OL plasma membrane. J. Neurosci. Res. 66:242–253, 2001. © 2001 Wiley‐Liss, Inc.
Cognitive divergence and shared mental models in software development project teams
Authors: Levesque Laurie L. , Wilson Jeanne M. , Wholey Douglas R.
Published: August 2002

This study examined the development of shared mental models in software development teams over time. Contrary to predictions, team members' mental models about the group's work and each other's expertise did not become more similar over time. Structural equation modelling revealed that as role differentiation increased in these teams, it led to a decrease in interaction and a corresponding decline in shared mental models. Implications for research on shared cognition and team development are explored. Copyright © 2001 John Wiley & Sons, Ltd.
Spatial distribution and its seasonality of satellite‐derived vegetation index (NDVI) and climate in Siberia
Authors: Suzuki Rikie , Nomaki Tomoyuki , Yasunari Tetsuzo
Published: August 2002

The Normalized Difference Vegetation Index (NDVI) distribution and its seasonal cycle were investigated in relation to temperature and precipitation over Siberia and its surrounding regions. The analyses used 5‐year (1987–1991) monthly means. The monthly mean NDVI was calculated from the third‐generation monthly Global Vegetation Index (GVI) product; monthly temperature and precipitation at 611 stations were calculated from Global Daily Summary (GDS) data.

The 611 stations were classified by cluster analysis into 10 classes based on the NDVI seasonal cycle (March–October). The geographical distribution characteristics of the NDVI cycle were described using temperature, precipitation and Olson's land‐cover type. In northern regions, where tundra vegetation prevails and temperatures and precipitation are low, the amplitude of the NDVI seasonal cycle is small. In southern regions, where temperatures are high and there is little precipitation, the seasonal amplitude of the NDVI is small because of the arid land type. Forested regions were split into six classes, each characterized by large amplitudes in the NDVI seasonal cycle. The phenological characteristics of the forest classes were noted. For example, a forest‐class localized near Lake Baikal shows higher NDVI values, even with the presence of snow cover in March, compared with other regions. This high NDVI value suggests that the exposed green canopy of the coniferous forest can be observed even when snow is present. In addition, the NDVI peaks at stations near 60°N, where the maximum monthly temperature is around 18°C. This result suggests that the optimum temperature‐precipitation environment coincides to the area in Siberia where the maximum monthly temperature is 18°C. Copyright © 2001 Royal Meteorological Society
Spatial and temporal 850 hPa air temperature and sea‐surface temperature covariances in the Mediterranean region and their connection to atmospheric circulation
Authors: Lolis C. J. , Bartzokas A. , Katsoulis B. D.
Published: August 2002

The spatial and temporal covariability between the lower troposphere and sea surface temperatures (SSTs) are studied in the Mediterranean basin for the period 1958–98. Monthly air temperature anomalies for the 850 hPa pressure level (T‐850hPa) at 2.5° × 2.5° grid points and SST anomalies in 5° × 5° grid boxes are utilized. As a first step, factor analysis is applied on both sets of data in order to reduce their dimensionality. Then, canonical correlation analysis is applied and this leads to one statistically significant pair of canonical variates for winter and to two pairs for summer. In winter, a teleconnection (see‐saw) between western Europe and the eastern Mediterranean at the 850 hPa level is revealed, and a corresponding weaker one between the areas of central‐west and eastern Mediterranean for SST. The correlation between T‐850hPa and SST appears higher over the eastern Mediterranean. In summer, the first pair of canonical variates reveals a covariability between T‐850hPa and SST in the western Mediterranean, and the second one shows a covariability in the eastern Mediterranean, without the existence of any strong spatial teleconnection. The analysis is repeated, using time lags of 1 month, or longer, in order to detect any possible non‐synchronous relation. Statistically significant results are found only when T‐850hPa leads SST with a time lag of 1 month. In particular, the results are statistically significant for winter only, and the findings are similar to those of the first analysis. Therefore, the existence of a 1 month time scale SST persistence is detected for winter months. Copyright © 2002 Royal Meteorological Society.
Geochemistry, dispersal, volumes and chronology of Holocene silicic tephra layers from the Katla volcanic system, Iceland
Authors: Larsen Gudrún , Newton Anthony J. , Dugmore Andrew J. , Vilmundardóttir Elsa G.
Published: August 2002

At least 12 silicic tephra layers (SILK tephras) erupted between ca. 6600 and ca. 1675 yr BP from the Katla volcanic system, have been identified in southern Iceland. In addition to providing significant new knowledge on the Holocene volcanism of the Katla system which typically produces basaltic tephra, the SILK tephras form distinct and precise isochronous marker horizons in a climatically sensitive location close to both the atmospheric and marine polar fronts. With one exception the SILK tephras have a narrow compositional range, with SiO2 between 63 and 67%. Geochemically they are indistinguishable from ocean transported pumice found on beaches in the North Atlantic region, although they differ significantly from the silicic component of the North Atlantic Ash Zone One (NAAZO). Volumes of airborne SILK tephra range from 0.05 to 0.3 km3. We present new isopach maps of the six largest layers and demonstrate that they originate within the Katla caldera. The apparently stable magma system conditions that produced the SILK tephras may have been established as a consequence of the eruption of the silicic component of NAAZO (ca. 10.3 ka) and disrupted by another large‐scale event, the tenth century ad Eldgjá eruption (ca. 1 ka). Despite the current long repose, silicic activity of this type may occur again in the future, presenting hitherto unknown hazards. Copyright © 2001 John Wiley & Sons, Ltd.
Chronology of latest Pleistocene lake‐level fluctuations in the pluvial Lake Chewaucan basin, Oregon, USA
Authors: Licciardi Joseph M.
Published: August 2002

New accelerator mass spectrometer radiocarbon ages from gastropods in shore deposits within the pluvial Lake Chewaucan basin, combined with stratigraphical and geomorphological evidence, identify an abrupt rise and fall of lake level at ca. 12 14C ka. The lake‐level high is coeval with lake‐level lows in the well‐dated records of palaeolakes Bonneville and Lahontan, and with a period of relatively wet conditions in the more southerly Owens Lake basin. This spatial pattern of pluvial lake levels in the western USA at 12 14C ka indicates a variable synoptic response to climate forcing at this time. Copyright © 2001 John Wiley & Sons, Ltd.
Late Quaternary depositional history of the Reuss delta, Switzerland: constraints from high‐resolution seismic reflection and georadar surveys
Authors: Nitsche Frank O. , Green Alan G. , Horstmeyer Heinrich , Büker Frank
Published: August 2002

Glacial erosion has caused overdeepening of many alpine valleys. After retreat of the ice, they were filled with heterogeneous deposits of glacial, lacustrine and fluvial sediments. A typical example of such a valley segment and its infill is the Reuss delta on the southern shore of Lake Lucerne in Switzerland. To obtain a detailed three‐dimensional image of this valley segment, the ETH Institute of Geophysics has acquired several two‐dimensional, high‐resolution seismic and georadar profiles, and conducted a three‐dimensional georadar survey. Interpretations of these geophysical data were constrained by a geological core extracted from a borehole 300 m deep near the investigation site. The seismic profiles imaged ca. 600 m of sediment infill above bedrock. Based on their reflection characteristics, five different deposition units were distinguished. These units were interpreted as a succession of clay/silt at the base, followed by different sand units with variable but generally increasing amounts of gravel. This succession represented a prograding delta that filled the southern part of Lake Lucerne. The latest fluvial development of the region is best represented by the georadar data. In particular, the three‐dimensional georadar data set provides a detailed view of an ancient braided river channel Copyright © 2002 John Wiley & Sons, Ltd.
Application of artificial neural networks (ANN) to high‐latitude dinocyst assemblages for the reconstruction of past sea‐surface conditions in Arctic and sub‐Arctic seas
Authors: Peyron Odile , Vernal Anne de
Published: August 2002

The artificial neural network (ANN) method was applied to dinoflagellate cyst (dinocyst) assemblages to estimate palaeoceanographical conditions. The ANN method was adapted to three distinct data bases covering the northern North Atlantic (N = 371), plus the Arctic seas (N = 540) and the Bering Sea (N = 646). The relative abundance of 23 dinocyst taxa was calibrated against hydrographic variables (sea‐surface temperature, salinity and density in February and August, and seasonal extent of sea‐ice cover) using ANNs. The estimation of hydrographical parameters based on an ANN yields high coefficients of correlation between observations and reconstructions for each variable selected. The validation tests performed on the different data bases suggest more accurate calibration at the scale of the North Atlantic and Arctic (N = 540) than on a multibasin scale, i.e. when including the subpolar North Pacific (N = 646). The ANN calibrations and the modern analogue technique (MAT) have been applied to two sequences from the northwest North Atlantic spanning the past 25 000 yr for the purpose of comparison. Both approaches yielded similar results, generally within the range of their respective uncertainties, demonstrating their suitability. The main discrepancies generally correspond to assemblages with poor modern analogues for which we have to admit a higher degree of uncertainties in the reconstruction, whatever the approach used. Copyright © 2001 John Wiley & Sons, Ltd.
Keto–enol tautomerism in β‐ketoesters: CH3C(O)CHXC(O)OY (X = H, Cl; Y = CH3, C2H5). Vibrational analyses, NMR spectra and quantum chemical calculations
Authors: Schiavoni M. M. , Di Loreto H. E. , Hermann A. , Mack H.‐G. , Ulic S. E. , Della Védova C. O.
Published: August 2002

The tautomeric equilibria of the β‐ketoesters [CH3C(O)CH2C(O)OCH3 (I), CH3C(O)CHClC(O)OCH3 (II), CH3C(O)CH2C(O)OCH2CH3 (III) and CH3C(O)CHClC(O)OCH2CH3 (IV)] were studied by NMR spectroscopy and, in the case of I and II, by quantum chemical calculations (ab initio and density functional methods). In addition, liquid‐state Fourier transform infrared and Raman spectra were analysed for all four compounds. They revealed the existence of two tautomers, diketo and enol forms. In the NMR spectra only signals for the diketo form could be observed for I and III. However, the calculations for I and II predicted the enol structures to be the most stable species. Copyright © 2001 John Wiley & Sons, Ltd.
Raman spectroscopy of polymer latexes
Authors: van den Brink Mark , Pepers Michel , van Herk Alex M.
Published: August 2002

The influence of elastic light scattering on the Raman signal of polymer latexes was investigated by varying the sample position relative to the confocal Raman probe. Measurements on polystyrene latexes revealed that the absolute Raman signal is very sensitive to the alignment of the sample. Furthermore, it was shown that for particle sizes below 140 nm and solid weight contents below 20%, changes in the absolute Raman signal can be described fairly well by turbidity laws. For larger particle sizes and higher solid weight contents deviations occur, but a correlation between these variables and the Raman signal still exists. In contrast, the normalized intensities are not influenced by varying the sample alignment in measurements on polymer latexes when using an excitation laser source at 532 nm. The important consequence of this is that the determination of chemical composition is not influenced by the elastic light scattering effects. Copyright © 2002 John Wiley & Sons, Ltd.
A research policy note on UK government support and small firms' internationalization using the Internet: The use of www.tradeuk.com
Authors: Chaudhry Shiv , Crick Dave
Published: August 2002

The perceived usefulness of thewww.tradeuk.com website was influenced by the international orientation of key decision makers together with their experience and commitment to pursuing overseas activities and the resources at their disposal. It was viewed as an additional and perhaps passive route to generating extra sales in the international marketplace.

Policy makers have attempted to implement a trade support system that embraces the advantages of new technology over its predecessors such as bulletin boards and off‐line directories. Sales leads can be quickly delivered to firms and businesses can potentially get a global exposure, depending on who logs on to the site.

At this stage the usefulness of www.tradeuk.com may be limited and may be more useful for firms with limited international experience that need leads to be made available.

In terms of change management, policy makers need to monitor and learn from what has happened with www.tradeuk.com in order to make potential improvements. It is important to establish at what stage of international development firms need the program most and for what specific purpose.

Copyright © 2002 John Wiley & Sons, Ltd.
Effects of harvesting procedure, storage time and climatic conditions on cooking time of lentils (Lens culinaris Medikus)
Authors: Iliadis C
Published: August 2002

In an experiment conducted over 2 years in Larissa, the effects on the cooking times of six lentil varieties of different harvest periods (early and late), seed storage for 1 year and climatic conditions prevailing during seed production were studied. Cooking time was estimated by measuring seed hardness using a penetrometer (PNR‐6). Late harvesting (when the plants were completely dry) increased cooking times by 6–16% in comparison with early harvesting (when the plants were partly green). This increase was less for the short‐cooking genotypes ‘Dimitra’, ‘Samos’ and ‘Thessalia’ than for the long‐cooking genotypes ‘Arachova’ and ‘Nikaia’. After 1 year of seed storage, cooking times increased on average by 6–9%. Seeds produced during a dry year (1995) required on average 38% less time to cook than seeds produced during a wet year (1996), irrespective of harvest period or duration of seed storage.

© 2001 Society of Chemical Industry
Organic agriculture: does it enhance or reduce the nutritional value of plant foods?
Authors: Brandt Kirsten , Mølgaard Jens Peter
Published: August 2002

The possible differences between organic and conventional plant products are examined from the view of possible effects on human health. It is concluded that nutritionally important differences relating to contents of minerals, vitamins, proteins and carbohydrates are not likely, primarily since none of these are deficient in typical First World diets, nor are present levels of pesticide residues in conventional products a cause for concern. However, there is reason to believe that contents of many defence‐related secondary metabolites in the diet are lower than optimal for human health, even for those where too high levels are known to be harmful. High biological activity resulting in adverse effects on growth of animals and children may be directly linked with promotion of longevity. There is ample, but circumstantial, evidence that, on average, organic vegetables and fruits most likely contain more of these compounds than conventional ones, allowing for the possibility that organic plant foods may in fact benefit human health more than corresponding conventional ones. The authors define testable scientific hypotheses which should be further investigated to provide more definitive answers to the question.

© 2001 Society of Chemical Industry
Amylolysis of maize mutant starches
Authors: Gérard Catherine , Colonna Paul , Buléon Alain , Planchot Véronique
Published: August 2002

Starches from single and double maize mutants were subjected to enzymatic degradation by porcine pancreatic α‐amylase. The maize mutants covered a broad range of macromolecular composition and crystalline structure relative to fractional crystallinity level (from 0.19 to 0.48) and polymorphic type (with various proportions of A‐, B‐ and V‐type allomorphs). Regardless of amylose content or crystallinity level, starches with a predominant B‐crystalline type were more resistant to amylolysis than others, and initial rates of hydrolysis were lower for B‐type than A‐type starches. Final hydrolysis extents were less than 35% for predominant B‐type starches, 60% for C‐type ones and more than 70% for predominant A‐ or V‐type ones. Dangling chains or crystal defects also appeared to increase initial hydrolysis rates, although lower initial rates and final hydrolysis extents were mainly related to the amount of B‐type crystallites. Unexpectedly, hydrolysis residues were composed of both amorphous and B‐type crystalline regions. These observations suggest that resistance to amylolysis is related to the distribution of B‐type crystallites within the granule rather than to the relative proportion of B‐type crystallites.

© 2001 Society of Chemical Industry