bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperosmotic stress‐induced apoptosis and tau phosphorylation in human neuroblastoma cells
Authors: Stoothoff William H. , Johnson Gail V.W. 
Published: August 2002

AbstractA characteristic hallmark of Alzheimer's disease brain is the presence of hyperphosphorylated tau; however, the mechanisms responsible for the aberrant tau phosphorylation are unknown. Recently, it has been shown that apoptotic‐like processes may be involved in some of the neuronal loss in Alzheimer's disease. In consideration of these findings, the relationship between tau phosphorylation and apoptosis was examined in human neuroblastoma SH‐SY5Y cells that were subjected to hyperosmotic stress. In this model caspase 3 activity, which served as an indicator of apoptosis, was increased by 30 min of osmotic stress and remained elevated through 4 hr. Hyperosmotic stress also resulted in a robust increase in tau phosphorylation at both Ser/Pro and non‐Ser/Pro sites. Phosphorylation of Ser262/356 (12E8) and Ser396/404 (PHF‐1) increased by 5 min and remained elevated for at least 1 hr. In contrast, phosphorylation within the Tau‐1 epitope did not increase (as evidenced by decreased immunoreactivity) until 30 min after treatment but remained elevated for a much greater period of time. Treatment with insulin‐like growth factor‐1 delayed but did not prevent apoptotic cell death induced by osmotic stress and attenuated the increase in phosphorylation at the Tau‐1 epitope. Li+, an inhibitor of glycogen synthase kinase 3β, had no effect on osmotic stress‐induced caspase activation, but reduced phosphorylation at the Tau‐1 epitope. Complete inhibition of osmotic stress‐induced caspase activation with DEVD‐CHO had no effect on the increases in tau phosphorylation. The results of these studies demonstrate that tau phosphorylation is increased at the specific epitopes during apoptosis. However, the changes in tau phosphorylation likely do not significantly impact the apoptotic process but rather occur concurrently as a result of inappropriate activation of specific protein kinases. Nonetheless, there is increasing evidence of a dysregulation of protein kinases that occurs in Alzheimer's disease brain that may be part of the events of apoptosis, which could contribute to aberrant increases in tau phosphorylation. J. Neurosci. Res. 65:573–582, 2001. © 2001 Wiley‐Liss, Inc.
Lovastatin treatment decreases mononuclear cell infiltration into the CNS of Lewis rats with experimental allergic encephalomyelitis
Authors: Stanislaus Romesh , Singh Avtar K. , Singh Inderjit 
Published: August 2002

AbstractMononuclear cell infiltration into the CNS and induction of inflammatory cytokines and iNOS in diseases like multiple sclerosis (MS) and experimental allergic encephalomyelitis (EAE) have been implicated in subsequent disease pathogenesis and progression. We report that Lovastatin treatment blocks the clinical disease and induction of inflammatory cytokines and iNOS in spinal cords of MBP induced EAE rats. A significant number of the infiltrating cells in CNS were ED1+ cells of monocyte/macrophage lineage. To understand the mechanism of efficacy of Lovastatin against EAE, we examined the effect of Lovastatin on the transmigration of mononuclear cells into EAE spinal cord. The data presented here documents that Lovastatin treatment attenuates the transmigration of mononuclear cells possibly by down regulating the expression of LFA‐1, a ligand for ICAM, in endothelial‐leukocyte interaction. These results indicate that Lovastatin treatment prevents infiltration by mononuclear cells into the CNS of rats induced for EAE, thereby lessening the histological changes and clinical signs and thus ameliorating the disease. These observations indicate that Lovastatin treatment may be of therapeutic value against inflammatory disease process associated with infiltration of activated mononuclear cells into the tissue. J. Neurosci. Res. 66:155–162, 2001. © 2001 Wiley‐Liss, Inc.
Channel activity of deamidated isoforms of prion protein fragment 106–126 in planar lipid bilayers
Authors: Kourie Joseph I. , Farrelly Peter V. , Henry Christine L. 
Published: August 2002

AbstractUsing the lipid bilayer technique, we have found that age‐related derivatives, PrP[106–126] (L‐Asp108) and PrP[106–126] (L‐iso‐Asp108), of the prion protein fragment 106–126 (PrP[106–126] (Asn108)) form heterogeneous ion channels. The deamidated isoforms, PrP[106–126] (L‐Asp108) and PrP[106–126] (L‐iso‐Asp108), showed no enhanced propensity to form heterogeneous channels compared with PrP[106–126] (Asn108). One of the PrP[106–126] (L‐Asp108)‐ and PrP[106–126] (L‐iso‐Asp108)‐formed channels had three kinetic modes. The current–voltage (I–V) relationship of this channel, which had a reversal potential, Erev, between –40 and –10 mV close to the equilibrium potential for K+ (EK –35 mV), exhibited a sigmoidal shape. The value of the maximal slope conductance (gmax) was 62.5 pS at positive potentials between 0 and 140 mV. The probability (Po) and the frequency (Fo) of the channel being open had inverted and bell‐shaped curves, respectively, with a peak at membrane potential (Vm) between –80 and +80 mV. The mean open and closed times (To and Tc) had inverted bell‐shaped curves. The biophysical properties of PrP[106–126] (L‐Asp108)‐ and PrP[106–126] (L‐iso‐Asp108)‐formed channels and their response to Cu2+ were similar to those of channels formed with PrP[106–126] (Asn108). Cu2+ shifted the kinetics of the channel from being in the open state to a “burst state” in which rapid channel activities were separated by long durations of inactivity. The action of Cu2+ on the open channel activity was both time‐dependent and voltage‐dependent. The fact that Cu2+ induced changes in the kinetics of this channel with no changes in the conductance of the channel indicated that Cu2+ binds at the mouth of the channel. Consistently with the hydrophilic and structural properties of PrP[106–126], the Cu2+‐induced changes in the kinetic parameters of this channel suggest that the Cu2+ binding site could be located at M109 and H111 of this prion fragment. J. Neurosci. Res. 66:214–220, 2001. © 2001 Wiley‐Liss, Inc.
Regional serotonin metabolism in the brain of transgenic mice lacking monoamine oxidase A
Authors: Popova Nina K. , Gilinsky Michael A. , Amstislavskaya Tamara G. , Morosova Ekaterina A. , Seif Isabelle , De Maeyer Edward 
Published: August 2002

AbstractThe effect of a lack of the gene encoding monoamine oxidase A (MAO A) in transgenic Tg8 mice on the activity of tryptophan hydroxylase (TPH), the rate‐limiting enzyme in serotonin (5‐HT) biosynthesis, and on the levels of 5‐HT and 5‐hydroxyindoleacetic acid (5‐HIAA) in the midbrain, hypothalamus, hippocampus, striatum, amygdala, and frontal cortex was studied. It was shown that mice with a genetic MAO A knockout differed from mice of the initial C3H/HeJ strain in having a higher level of 5‐HT and a lower level of its metabolite, 5‐HIAA, in all brain regions but the frontal cortex, where the changes were insignificant. Although the 5‐HIAA/5‐HT ratio in various brain regions differed considerably, the decrease of the 5‐HT oxidative deamination index in Tg8 mice was similar in different brain regions (to 41–45% of control values), with the exception of the frontal cortex, where the decrease of the 5‐HIAA/5‐HT was somewhat smaller (to 54%). The presence of the remaining 45% ± 1.9% of the control ratio value indicates rather effective oxidative deamination of 5‐HT in MAO A knockout mice and explains the lack of severe behavioral and pathological consequences in MAO A genetic deficiency. An increase of TPH activity in mice lacking MAO A was found in the frontal cortex, hippocampus, and amygdala. No significant changes were found in the striatum, hypothalamus, and midbrain. The data show an effect of the MAO A gene mutation on TPH and indicate a uniform decrease of 5‐HT catabolism in different brain regions except for the frontal cortex, which is somewhat more resistant to the lack of MAO A than other brain structures. J. Neurosci. Res. 66:423–427, 2001. © 2001 Wiley‐Liss, Inc.
Methamphetamine induces AP‐1 and NF‐κB binding and transactivation in human brain endothelial cells
Authors: Lee Yong Woo , Hennig Bernhard , Yao Jin , Toborek Michal 
Published: August 2002

AbstractCellular and molecular mechanisms of methamphetamine (METH)‐induced neurotoxicity may involve alterations of cellular redox status and induction of inflammatory genes in endothelial cells. To study these hypotheses, molecular signaling pathways of METH‐induced inflammatory responses via activation of redox‐sensitive transcription factors were investigated in human brain microvascular endothelial cells (HBMEC). A dose‐dependent depletion of total glutathione levels was detected in HBMEC exposed to METH. In addition, electrophoretic mobility shift assay (EMSA) showed significant increases in DNA binding activities of redox‐responsive transcription factors, AP‐1 and NF‐κB, in HBMEC treated with METH. METH‐mediated AP‐1 or NF‐κB activation was accompanied by induction of transactivation of AP‐1 or NF‐κB, as measured by dual luciferase assay using specific reporter plasmids. Because NF‐κB and AP‐1 are known to regulate expression of inflammatory genes, expression of the gene encoding for tumor necrosis factor‐α (TNF‐α) was also studied in METH‐treated HBMEC. A dose‐dependent overexpression of the TNF‐α gene was observed in HBMEC treated with METH. The importance of AP‐1 and NF‐κB in METH‐induced TNF‐α gene was confirmed in functional promoter studies using constructs of the TNF‐α promoter with mutated AP‐1 or NF‐κB sites. These results indicate that METH‐induced disturbances in cellular redox status and activation of AP‐1 and NF‐κB can play critical roles in the signaling pathways leading to upregulation of inflammatory genes in human brain endothelial cells. J. Neurosci. Res. 66:583–591, 2001. © 2001 Wiley‐Liss, Inc.
Job satisfaction: a meta‐analysis of stabilities
Authors: Dormann Christian , Zapf Dieter 
Published: August 2002

AbstractEvidence suggesting that job satisfaction is caused by individual dispositions is reviewed, and stability coefficients for job satisfaction in previous studies are analysed with a meta‐analytic procedure. Previous longitudinal studies analysing job changer samples imply an upper limit estimate of 0.51 for direct dispositional influences on job satisfaction. A study of job changers considering the stability of working conditions suggests that this estimate has to be considerably corrected downwards. At present, it is concluded that it is more likely that dispositions indirectly affect job satisfaction via selection and self‐selection processes. Implications for job satisfaction as a tool for organizational assessment are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
Indo‐Pacific relationships in terms of sea‐surface temperature variations
Authors: Sewell Richard D. , Landman Willem A. 
Published: August 2002

AbstractIn the last decade, a great deal of attention has been paid to the irregular interannual oscillation, known to the acronym writers as ENSO, or El Niño–Southern Oscillation. Algorithms have been developed which model the interaction between the ocean and the atmosphere, and because of the dependency of such modelling on the state of the oceans, various attempts have been made to predict the sea‐surface temperature (SST) anomalies and, further, to understand the relationship between the oceans and their role in the global propagation of the ENSO signal. To this end, a statistical study, using singular value decomposition (SVD), has been made of the relationship between the SSTs of the Pacific and Indian Oceans in the last 4 decades and, in particular, the changes which have taken place, especially in the Indian Ocean. The point of using SVD is that it enables the user to compare the Pacific and Indian Oceans as two separate entities with different dimensions, not one as an adjunct of the other. For the purpose of this analysis, it is assumed that the two oceans are distinct and have separate characteristics. A simple EOF analysis treating the two oceans as one tropical system, for example, would not accomplish this objective. While SVD analyses in meteorology and climatology have mainly been applied to two different meteorological parameters, for example SST and sea level pressure, in the same area, there is no valid reason why SVD should not be applied to the same (or different) parameter(s) in different regions. Although the Indian and Pacific Oceans are of different dimensions, SVD does not weight the result in favour of either the smaller or the larger of the two. SVD is a statistical tool which gives results comparable with canonical correlation analysis, though several authors warn against its indiscriminate use. It is found that the Indian Ocean SSTs have a strong association with Pacific Ocean SSTs, particularly when the Indian Ocean lags the Pacific Ocean by one season in mid‐summer. It is also found that there is a distinct change in the SST patterns in the equatorial Indian Ocean in the second half (1977–1996) of the period under study. Copyright © 2001 Royal Meteorological Society
The cause of warming over Norway in the ECHAM4/OPYC3 GHG integration
Authors: Benestad Rasmus E. 
Published: August 2002

AbstractThe cause of warming over Norway in a future global climate model (GCM) scenario is examined. Analysis of historical observations indicate that the observed long‐term temperature trends are not a result of systematic shifts in the North Atlantic Oscillation (NAO). The GCM prediction of past and future warming cannot be explained in terms of changes to the large‐scale atmospheric flow. The climate model results may suggest that the model has a seasonal bias with respect to the time of the year when the fastest warming occurs.The NAO is associated with the warming after 1970, even though the 1860–1997 temperature trends do not appear to be connected with the NAO. An accurate description of the NAO is, therefore, critical for forecasting short‐term variability in the Norwegian winter climate and the results obtained here suggest that the model description of the NAO is generally good. Copyright © 2001 Royal Meteorological Society.
A conceptual model for understanding rainfall variability in the West African Sahel on interannual and interdecadal timescales
Authors: Nicholson S.E. , Grist J.P. 
Published: August 2002

AbstractThis article describes and validates a new conceptual model for understanding Sahel rainfall variability. This conceptual model provides a framework that can readily incorporate and synthesize the roles played by the oceans, the African landmass and local meteorological factors. The most important ‘local’ factors are the location of the African Easterly Jet (AEJ) and the associated shears. The position of the AEJ helps to distinguish between a ‘wet mode’ and a ‘dry mode’ in the Sahel, while other factors determine which of two spatial patterns prevail during years of the dry regime. We test the paradigm by contrasting selected circulation parameters for the years 1958–1967 (representing the wet mode) and 1968–1997 (representing the dry mode). In doing so, we have identified several changes in the general atmospheric circulation that have accompanied the shift to drier conditions. The AEJ is further southward and more intense, the Inter‐tropical Convergence Zone (ITCZ) is further south, the Tropical Easterly Jet (TEJ) is weaker, the equatorial westerlies are shallower and weaker, the southwesterly monsoon flow is weaker, and the relative humidity is lower (but not consistently so).The results of this study suggest that the key factor controlling the occurrence of the ‘wet Sahel’ mode versus the ‘dry’ mode is the presence of deep, well‐developed equatorial westerlies. These displace the AEJ northward into Sahelian latitudes and increase the shear instabilities. The westerlies appear to be at least partially responsible for the well‐known association between a weaker AEJ and wetter conditions in the Sahel, because the thermal wind induced by the Sahara/Atlantic temperature gradient is imposed upon a westerly basic state. Since one of the strongest contrasts between the ‘wet Sahel’ and ‘dry Sahel’ modes is the strength of the TEJ, the TEJ probably also plays a pivotal role in rainfall variability. In the dry mode, the equatorial westerlies are poorly developed and the core of the AEJ lies well to the south of the Sahel. The dry mode consists of two basic spatial patterns, depending on whether the Guinea Coast Region is anomalously wet or dry (the well‐known dipole and no‐dipole patterns, respectively). Which occurs is determined by other factors acting to reduce the intensity of the rainbelt. One of the relevant factors appears to be sea‐surface temperatures (SSTs) in the Gulf of Guinea. Copyright © 2001 Royal Meteorological Society
Problems in evaluating regional and local trends in temperature: an example from eastern Colorado, USA
Authors: Pielke SR R. A. , Stohlgren T. , Schell L. , Parton W. , Doesken N. , Redmond K. , Moeny J. , McKee T. , Kittel T. G. F. 
Published: August 2002

AbstractWe evaluated long‐term trends in average maximum and minimum temperatures, threshold temperatures, and growing season in eastern Colorado, USA, to explore the potential shortcomings of many climate‐change studies that either: (1) generalize regional patterns from single stations, single seasons, or a few parameters over short duration from averaging dissimilar stations; or (2) generalize an average regional pattern from coarse‐scale general circulation models. Based on 11 weather stations, some trends were weakly regionally consistent with previous studies of night‐time temperature warming. Long‐term (80 + years) mean minimum temperatures increased significantly (P < 0.2) in about half the stations in winter, spring, and autumn and six stations had significant decreases in the number of days per year with temperatures ≤ − 17.8 °C (≤0 °F). However, spatial and temporal variation in the direction of change was enormous for all the other weather parameters tested, and, in the majority of tests, few stations showed significant trends (even at P < 0.2). In summer, four stations had significant increases and three stations had significant decreases in minimum temperatures, producing a strongly mixed regional signal. Trends in maximum temperature varied seasonally and geographically, as did trends in threshold temperature days ≥32.2 °C (≥90 °F) or days ≥37.8 °C (≥100 °F). There was evidence of a sub‐regional cooling in autumn's maximum temperatures, with five stations showing significant decreasing trends. There were many geographic anomalies where neighbouring weather stations differed greatly in the magnitude of change or where they had significant and opposite trends. We conclude that sub‐regional spatial and seasonal variation cannot be ignored when evaluating the direction and magnitude of climate change. It is unlikely that one or a few weather stations are representative of regional climate trends, and equally unlikely that regionally projected climate change from coarse‐scale general circulation models will accurately portray trends at sub‐regional scales. However, the assessment of a group of stations for consistent more qualitative trends (such as the number of days less than −17.8 °C, such as we found) provides a reasonably robust procedure to evaluate climate trends and variability. Copyright © 2002 Royal Meteorological Society
Daily wind gust speed probabilities over Switzerland according to three types of synoptic circulation
Authors: Jungo Patricia , Goyette Stéphane , Beniston Martin 
Published: August 2002

AbstractThe nowcasting and prediction of strong winds are still far from adequate, using either statistical or numerical modelling approaches. During the last decade, Switzerland has been struck by two extratropical storms, namely the February 1990 storm ‘Vivian’, and the December 1999 storm ‘Lothar’, that caused severe damage to infrastructure and to forests. Although numerical weather prediction models captured in both cases the cyclone tracks on the synoptic scale, the severity of local gusts was not properly predicted over the Swiss territory. To help predicting such phenomena, a combined approach to diagnose the wind gust speeds over Switzerland is described. The diagnostics aim at computing the probability of exceeding a gust speed based on the mean wind in relation to the prevailing synoptic weather type for a limited number of groups of climatological stations distributed throughout Switzerland. Based on 10 years of Swiss station observations, the computation of this probability uses an empirical gust factor that is a function of the daily gust speed, itself a function of the daily mean wind speed. For this period, each day has been categorized into three weather types according to the Schüepp classification. Principal component analysis and cluster analysis are performed in order to group climatological stations having similar characteristics in daily wind gust velocities. The results show that the gust factor provides an accurate method to compute the daily wind gust speeds at each Swiss climatological station for the given period. When combined with the three weather types and group of stations, the proposed diagnostics are an efficient method to predict the distribution of wind gust speeds. The gusts associated with the ‘Vivian’ and ‘Lothar’ storms are then diagnosed for each specific group where more than 85% of the stations responded similarly to their specific group members, which is highly satisfactory in this case. Copyright © 2002 Royal Meteorological Society
Dinoflagellate cyst assemblages in surface sediments of the Laptev Sea region (Arctic Ocean) and their relationship to hydrographic conditions
Authors: Kunz‐Pirrung Martina 
Published: August 2002

AbstractThe occurrence and distribution of dinoflagellate cysts in surface sediments from the Laptev Sea shelf and the adjacent continental margin have been studied in relation to surface water conditions. Assemblages were interpreted by visual inspection and Q‐mode factor analysis. The inner Laptev shelf is a type‐area for polar environments because of the near absence of relatively warm waters from the Pacific or Atlantic oceans and an extensive seasonal sea‐ice cover. Assemblages are of low diversity and are dominated by the cold water taxon Islandinium minutum and related morphotypes. The common occurrence of distinctive polykrikoid cyst morphotypes is an indicator of polar environments. Furthermore, a strong supply of fresh water in summer influences the surface water conditions, and is a major factor controlling the occurrence and distribution of dinoflagellate cysts. The dinoflagellate cysts Nematosphaeropsis labyrinthus and Operculodinium centrocarpum are restricted to the continental margin, suggesting a relation to the inflow of relatively warm Atlantic waters along the Eurasian continental margin. An abundance maximum of Brigantedinium spp. at the shelf break is related to the mean position of the marginal ice zone. Copyright © 2001 John Wiley & Sons, Ltd.