bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detection and identification of dengue‐1 virus in clinical samples by a nested‐PCR followed by restriction enzyme digestion of amplicons
Authors: De Paula Sérgio Oliveira , Lima Danielle Malta , da Fonseca Benedito Antônio Lopes 
Published: August 2002

AbstractDengue viruses cause a disease with clinical findings ranging from asymptomatic infections to severe manifestations, characterised by haemorrhage and shock and known as dengue haemorrhagic fever/dengue shock syndrome. Since this fever and syndrome usually results from sequential infections by distinct dengue serotypes, rapid detection and identification of dengue viruses circulating in endemic areas are important to implement control measures, and ultimately to avoid secondary infections that could result in dengue haemorrhagic fever/dengue shock syndrome. A nested‐PCR was developed followed by restriction enzyme (Kpn I) digestion of the amplicons to differentiate dengue‐1 from dengue‐2. Seventy‐five IgM‐containing samples collected from 2 to 17 days after the beginning of the symptoms were examined. These samples were submitted to nested‐PCR amplification, the amplicons were digested with Kpn I, and the results compared to virus isolation in C6/36 cells and to results obtained by the standard PCR. Out of 75 tested samples, virus was isolated from 2 (2.6%), 17 (22.7%) were positive by the regular PCR protocol, and 58 (77.3%) were positive by nested‐PCR. All of the amplicons digested by Kpn I identified dengue‐1 virus as the infecting strain. These results indicate that the nested‐PCR provided a high yield of dengue genome amplification even in the presence of IgM antibodies, and restriction enzyme digestion defined rapidly the circulating serotype. Therefore, the combination of these techniques may be useful to rapidly identify dengue viruses in countries where dengue‐1 and dengue‐2 circulates, and this approach can also be applied to the other two serotypes. J. Med. Virol. 66:529–534, 2002. © 2002 Wiley‐Liss, Inc.
Increased frequency of IFN‐γ‐producing peripheral CD8+ T cells with memory‐phenotype in patients with chronic hepatitis C
Authors: Murata Masayuki , Nabeshima Shigeki , Maeda Naoyasu , Nakashima Hisashi , Kashiwagi Seizaburo , Hayashi Jun 
Published: August 2002

AbstractTo identify the capacity for cytokine production and the phenotypic characteristics of peripheral CD8+ T cells in patients with chronic hepatitis C, 31 patients with chronic hepatitis C and 22 healthy controls were studied at the single cell level by three‐color flow cytometry. Whole blood was stained with surface CD8, intracellular interferon‐γ (IFN‐γ), and interleukin‐4 (IL‐4), surface CD8, CD28, and intracellular IFN‐γ after stimulation with PMA plus ionomycin, and then surface CD8, CD45RA, and CD28. IFN‐γ‐producing peripheral CD8+ T cells were found frequently in patients than in controls (P < 0.05), whereas IL‐4‐producing peripheral CD8+ T cells were not. Although the frequency of peripheral CD28+CD8+ and CD28−CD8+ T cells in patients was not different from that of controls, CD28+CD8+ T cells exceeded CD28−CD8+ T cells in the capacity for IFN‐γ‐production after mitogenic stimulation (P < 0.01). In a more detailed analysis of the CD28+CD8+ T cells, CD45RA−CD28+CD8+ T cells, defined phenotypically as memory cells, were found frequently in patients than in controls (P < 0.05). There were no significant correlations between the frequency of IFN‐γ‐producing peripheral CD8+ T cells and hepatitis C virus RNA level or serum alanine aminotransferase level in patients. These data suggest that functionally T cytotoxic type 1 and memory CD8+ T cells are predominant in the peripheral blood of chronic hepatitis C patients and that such activated CD8+ T cells are associated with liver damage. J. Med. Virol. 67:162–170, 2002. © 2002 Wiley‐Liss, Inc.
Expression and regulation of golli products of myelin basic protein gene during in vitro development of oligodendrocytes
Authors: Givogri Maria I. , Bongarzone Ernesto R. , Schonmann V. , Campagnoni Anthony T. 
Published: August 2002

AbstractThe myelin basic protein (MBP) gene produces two families of proteins, the classic MBPs, important for myelination of the CNS, and the golli proteins, whose biological role in oligodendrocytes (OLs) is still unknown. The goals of this work were to study the in vitro pattern of expression of the golli products during OL differentiation and to compare it with that of the classic MBP products of the gene. Mouse primary glial cultures were analyzed at the mRNA and protein levels with an array of techniques. We found that OLs express golli mRNA primarily during intermediate stages of differentiation, which was confirmed by immunocytochemical analysis. Golli expression was low in proliferating OL progenitors as well as in terminally mature OLs. Golli proteins were found associated with the OL cell soma and nuclei and, to a lesser extent, with the cellular processes. We also found that golli proteins are not targeted to myelin in vitro and in vivo, in contrast to the classic MBPs. Finally, we found that golli expression is regulated during OL development and can be manipulated by growth factors such as basic fibroblast growth factor, neurotrophin‐3, and retinoic acid. J. Neurosci. Res. 66:679–690, 2001. © 2001 Wiley‐Liss, Inc.
Potentiation of nuclear activator protein‐1 DNA binding following brief exposure to N‐methyl‐D‐aspartate in immature cultured rat hippocampal neurons
Authors: Hirai Takao , Kuramoto Nobuyuki , Maruyama Hiroko , Balcar Vladimir J. , Nakamura Yoichi , Yoneda Yukio 
Published: August 2002

AbstractSimilar potentiation was seen with the nuclear transcription factor activator preotein‐1 (AP1) binding in rat hippocampal neurons cultured for 3 and 9 DIV, when determined immediately after exposure to 500 μM N‐methyl‐D‐aspartate (NMDA) for 60–120 min. Growth‐associated protein‐43 was markedly expressed in hippocampal neurons cultured for 3–5 DIV, with a decline up to 9 DIV. In immature neurons cultured for 3 DIV, NMDA was effective in significantly potentiating AP1 binding even in the presence of Mg2+ with less potency than in the absence of Mg2+ when determined immediately after sustained exposure for 120 min. When determined 120 min after brief exposure for 5 min, by contrast, NMDA significantly potentiated AP1 binding at a range of 100–500 μM only in the absence of Mg2+ in immature neurons cultured for 3 DIV. At least 60 min was required for significant potentiation of AP1 binding as an interval between brief exposure and subsequent cell harvest. Dizocilpine abolished the potentiation determined 120 min after brief exposure to 500 μM NMDA, and both dantrolene and nifedipine were similarly effective in significantly preventing the potentiation at 10–50 μM. These results suggest that NMDA may potentiate AP1 binding following a sustained increase in intracellular free Ca2+ concentrations through influxes across NMDA‐operated and L‐type voltage‐sensitive Ca2+ channels, in addition to release from intracellular Ca2+ stores, in immature cultured rat hippocampal neurons. © 2002 Wiley‐Liss, Inc.
Detection of prolactin receptor mRNA in the corpus striatum and substantia nigra of the rat
Authors: Pi Xiujun , Voogt James L. , Grattan David R. 
Published: August 2002

AbstractThe observation of prolactin modulation of the nigrostriatal dopaminergic system suggests the expression of prolactin receptor in the corpus striatum or substantia nigra. The present study investigated expression of prolactin receptor mRNA in tissues microdissected from the corpus striatum and substantia nigra of the rat. By using reverse transcription PCR combined with Southern hybridization, the long form of prolactin receptor mRNA was detected in the substantia nigra, caudate putamen, globus pallidus, and ventral pallidum in ovariectomized rats, whereas the short form was not detectable in any of these areas. Estrogen had no effect on expression of the long‐form mRNA in the substantia nigra and corpus striatum. By using the RNase protection assay, the expression of both short and long forms of prolactin receptor mRNA was observed in the corpus striatum in ovariectomized rats. Again, levels of expression were not significantly altered by estrogen treatment. Both forms of prolactin receptor mRNA were clearly expressed in the choroid plexus and were up‐regulated by estrogen treatment. The expression of both forms of prolactin receptor mRNA in nigrostriatal areas may help to support the hypothesis that prolactin has direct actions on these brain regions. © 2002 Wiley‐Liss, Inc.
γ‐Aminobutyric acidA ρ receptor subunits in the developing rat hippocampus
Authors: Didelon Frédéric , Sciancalepore Marina , Savic' Natasa , Mladinic' Miranda , Bradbury Andrew , Cherubini Enrico 
Published: August 2002

AbstractThe RT‐PCR approach was used to estimate the expression of γ‐aminobutyric acid (GABA)A ρ receptor subunits in the hippocampus of neonatal and adult rats. All three ρ subunits were detected at postnatal day (P) 2, the ρ3 subunit being expressed at an extremely low level. The ρ1 and ρ2 products appeared to be developmentally regulated; they were found to be more pronounced in adulthood. In another set of experiments, to correlate gene expression with receptor function, GABAA ρ subunit mRNAs were detected with single‐cell RT‐PCR in CA3 pyramidal cells (from P3–P4 hippocampal slices), previously characterized with electrophysiological experiments for their bicuculline‐sensitive or ‐insensitive responses to GABA. In 6 of 19 cells (31%), pressure application of GABA evoked at –70 mV inward currents that persisted in the presence of 100 μM bicuculline (314 ± 129 pA). RT‐PCR performed in two of these neurons revealed the presence of ρ1 and ρ2 subunits, the latter being present with the α2 subunit. A ρ2 subunit was also found in 1 neuron (among 9) exhibiting a response to GABA, which was completely abolished by bicuculline. This might be due to the lack of putative accessory GABAA subunits that can coassemble with ρ2 to make functional receptors. Similar experiments from 10 P15 CA3 pyramidal cells failed to reveal any ρ1–3 transcripts. However, these neurons abundantly express α3 subunits. It is likely that in CA3 pyramidal cells of neonatal and adult hippocampus GABAA ρ subunits are present but at very low levels of expression. © 2002 Wiley‐Liss, Inc.
Bone morphogenetic proteins BMP‐6 and BMP‐7 have differential effects on survival and neurite outgrowth of cerebellar granule cell neurons
Authors: Yabe Takeshi , Samuels Ivy , Schwartz Joan P. 
Published: August 2002

AbstractThe bone morphogenetic proteins (BMPs) play an inductive role in the generation of cerebellar granule cells embryonically. Therefore, we chose to look at their effects on cerebellar granule cell survival and differentiation postnatally. The cells express mRNA for both BMP‐6 and BMP‐7, as well as for the receptors BMPRIA and BMPRII, demonstrating that the postnatal cells have the ability to form the heterodimer receptors needed to respond to BMPs. BMP‐7 promotes cell survival, with a maximal effect at 10 ng/ml, whereas tenfold more BMP‐6 is needed: Both were active over the course of 8 days in culture. In addition, both BMPs were able to protect the neurons against death from induced apoptosis (exposure to serum‐free, low‐potassium medium) or exposure to glutamate. However, only BMP‐6 could stimulate neurite outgrowth, measured with a neurofilament ELISA, an effect that was seen over the first 6 days in culture. These results, taken together with others in the literature, suggest that the BMPs have strong neurotrophic effects that are both neuron specific and BMP specific. Published 2002 Wiley‐Liss, Inc.
Time course of polyglutamine aggregate body formation and cell death: Enhanced growth in nucleus and an interval for cell death
Authors: Toyoshima I. , Sugawara M. , Kato K. , Wada C. , Shimohata T. , Koide R. , Onodera O. , Tsuji S. 
Published: August 2002

AbstractPolyglutamine (polyQ) aggregate bodies are a hallmark of dentatorubral‐pallidoluysian atrophy and related neurodegenerative disorders, although the relationship between aggregate body formation and cell death is not clear. We analyzed the kinetics of polyQ aggregate formation and the time intervals for cell death, tracking individual cells using fluorescence video microscopy, for the first time. Expanded polyQ tracts of atrophin‐1 with or without nuclear localization signal (NLS) labeled with green fluorescent protein (GFP) were constructed, Q57NLS/GFP and Q56/GFP, respectively. All of the Q57NLS/GFP aggregate bodies were in nuclei, and all of the Q56/GFP aggregate bodies were in cytoplasm. Aggregates of Q56/GFP were larger than those of Q57NLS/GFP. Surprisingly, a kinetic analysis showed that the latter grew 5.37 times faster than the former. The time interval between transfection and cell death was shorter in Q57NLS/GFP, but the time between the end of the rapid growing phase of aggregation and the start of the cell death process did not show a significant difference. Aggregate growth was confirmed to correspond to the accumulated free polyQ by the time of starting aggregation. These findings suggest that aggregate body formation induced by expanded polyQ stretches is a self‐limiting process and is enhanced by factor(s) in nuclei, whereas it is not tightly bound to the cell death process. © 2002 Wiley‐Liss, Inc.
Antibody to the extracellular domain of the low affinity NGF receptor stimulates p75NGFR‐mediated apoptosis in cultured sympathetic neurons
Authors: Freidin Mona M. 
Published: August 2002

AbstractRecent evidence has established a role for p75NGFR in developmentally regulated neuronal cell death. Although cell death due to NGF withdrawal is a well described, apoptosis in sympathetic neurons through stimulation of p75NGFR has not been clearly demonstrated. We have found that an antibody directed against the extracellular domain of murine p75NGFR profoundly effects the survival of short‐term cultures of sympathetic neurons. Rat superior cervical ganglion neurons grown in the presence of NGF and treated with the bioactive antibody (9651) display a dose‐dependent increase in cell death. This effect was independent of NGF concentration and partially reversed by either depolarizing stimuli or forskolin. The response to 9651 seems to act directly through a p75NGFR‐mediated pathway and not by disturbing p75NGFR/TrkA interactions. Moreover, the kinetics of antibody stimulated cell death was more rapid than the cell death resulting from removal of NGF and treatment with CNTF failed to promote neuronal survival in the presence of 9651. Initiation of cell death is often associated with decreased NFκB activity, whereas survival or rescue correlates with increased NFκB. Increases in NFκB, however, have been observed in neurons in several diseases and late in apoptosis in differentiated PC12 cells. Time course studies revealed a rapid decrease in NFκB activity and a slight, but persistent increase in binding that correlated with decline in cell numbers 3 hr after treatment. These results suggest the cell death program is initiated shortly after antibody activation of p75NGFR and a subpopulation of cells may remain susceptible to rescue. J. Neurosci. Res. 64:331–340, 2001. © 2001 Wiley‐Liss, Inc.
Caspase‐3 activation in oligodendrocytes from the myelin‐deficient rat
Authors: Beesley Jacqueline S. , Lavy LeaAnn , Eraydin Nuri B. , Siman Robert , Grinspan Judith B. 
Published: August 2002

AbstractThe myelin‐deficient (MD) rat has a point mutation in its proteolipid protein (PLP) gene that causes severe dysmyelination and oligodendrocyte cell death. Using an in vitro model, we have shown that MD oligodendrocytes initially differentiate similarly to wild‐type cells, expressing galactocerebroside, 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase, and myelin basic protein. However, at the time when PLP expression would normally begin, the MD oligodendrocytes die via an apoptotic pathway involving caspase activation. The active form of caspase‐3 was detected, along with the cleavage products of poly‐(ADP‐ribose) polymerase (PARP) and spectrin, major targets of caspase‐mediated proteolysis. A specific inhibitor of casapse‐3, Ac‐DEVD‐CMK, reduced apoptosis in MD oligodendrocytes, but the rescued cells did not mature fully or express myelin‐oligodendrocyte glycoprotein. These results suggest that mutant PLP affects not only cell death but also oligodendrocyte differentiation. J. Neurosci. Res. 64:371–379, 2001. © 2001 Wiley‐Liss, Inc.
Ceramide modulates nicotinic receptor‐dependent Ca2+ signaling in rat chromaffin cells
Authors: Liu Jihong , Jorgensen Mark S. , Adams Julye M. , Titlow William B. , Nikolova‐Karakashian Mariana , Jackson Brian A. 
Published: August 2002

AbstractCeramide, which is an integral component of the sphingomyelin signaling pathway, can attenuate voltage‐gated Ca2+ channel (VGCC) activity in a number of cell types. The aim of the present study was to determine whether ceramide can also modulate VGCC activity, and as a consequence nicotinic receptor‐dependent Ca2+ signaling and catecholamine secretion, in rat adrenal chromaffin cells. Short‐term C6‐ceramide (CER) treatment dose‐dependently inhibited nicotine (NIC)‐induced peak intracellular Ca2+ transients. Sphingomyelinase elicited similar responses, whereas the inactive ceramide analog C2‐dihydroceramide had no effect on NIC‐induced Ca2+ transients. CER suppressed KCl‐ and NIC‐induced Ca2+ transients to a similar extent, suggesting that the voltage‐gated Ca2+ channel was a primary site of inhibition. In direct support of this concept, whole‐cell patch‐clamp analysis demonstrated that CER and sphingomyelinase significantly reduced peak Ca2+ currents. Pretreatment with staurosporine significantly attenuated CER‐dependent inhibition of both NIC‐induced Ca2+ transients and peak Ca2+ current, suggesting that the effects of CER are mediated at least in part by protein kinase C. Consistent with suppressed Ca2+ signaling, CER also significantly inhibited NIC‐induced catecholamine secretion measured at the single‐cell level by carbon fiber amperometry. This effect of CER was also significantly attenuated by pretreatment with staurosporine These data demonstrate that the sphingomyelin signaling pathway can modulate nicotinic receptor‐dependent Ca2+ signaling and catecholamine secretion in rat chromaffin cells. J. Neurosci. Res. 66:559–564, 2001. © 2001 Wiley‐Liss, Inc.
Variations of the surface temperature in Hong Kong during the last century
Authors: Ding Xiaoli , Zheng Dawei , Yang Song 
Published: August 2002

AbstractA statistical analysis has been applied to obtain a better understanding of the variations of the surface climate in Southeast Asia. In particular, we have depicted the detailed features of the changes in the surface air temperature of Hong Kong (HK) during the past 115 years. Analysis of the time–frequency spectra of the wavelet transform indicates that although seasonal variations account for most of the temperature variations, strong signals also exist on subseasonal, interannual, and interdecadal time scales. Though the strong seasonal cycle is marked by a minimum temperature in February (and then in January) and a maximum temperature in July (and then in August), strong variations on the subseasonal and interannual time scales occur mostly in February and then in March. It is also found that a rising tendency exists in the long‐recorded temperature data, with a rate of 0.09–0.15 °C per decade.Temperature variations in HK are strongly related to changes in the regional and remote atmospheric circulation on various time scales. The East Asian monsoon circulation is the main factor controlling the seasonal cycle and the subseasonal and interannual variations of the HK temperature during winter. The subseasonal and seasonal variations of the temperature are also associated with changes in the atmospheric circulation over the North Pacific, which is closely linked to the East Asian jet stream. Strong signals are also found in both this mid‐latitude circulation and the El Niño–southern oscillation phenomenon when the interannual variability of the HK temperature is apparent. Copyright © 2002 Royal Meteorological Society.
Analyse vibrationnelle et structurale de composés à pont disulfure II—structures et spectres de vibration du dithiodiglycolate acide de sodium et de potassium monohydratés à l'état cristallin
Authors: Ramsis H. , Selkti M. , Roger J. , Delarbre J. L. , Tomas A. , Maury L. , Ennaciri et A. 
Published: August 2002

AbstractThe structures of the potassium and sodium salts of dithiodiglycolic acid were determined on the basis of radiocrystallographic measurements. These compounds and their deuterated analogs were identified by spectral analysis. Assignments of the Raman and infrared lines in the range 4000–200 cm−1 show that for these acid salts, one form belongs to type pseudo‐A and the second to type B according to Speakmann's classification. Copyright © 2001 John Wiley & Sons, Ltd.
Selective enhancement of ligand and flavin Raman modes in charge‐transfer complexes of sarcosine oxidase
Authors: Zheng Yuangang , Wagner Mary Ann , Jorns Marilyn Schuman , Carey Paul R. 
Published: August 2002

AbstractMonomeric sarcosine oxidase, from a bacterial source, is a 43.8 kDa flavoenzyme that catalyzes the oxidation of sarcosine (N‐methylglycine). The enzyme forms charge‐transfer (CT) complexes with substrate analogs such as (methylthio)acetic acid (MTA), pyrrole‐2‐carboxylic acid (PCA) and (methylseleno)acetic acid (MSA). The structure of sarcosine oxidase complexed to either of the former two ligands has been solved recently and shows that the ligands are binding close to the re face of the isoalloxazine ring. More structural detail can be adduced from Raman spectroscopic studies of these complexes. These involve collecting Raman difference data using 647.1 nm excitation, a wavelength that is in the resonance or pre‐resonance regime with regard to the CT bands. Selective intensity enhancements are observed and the difference spectra reveal a rich assortment of isoalloxazine modes and a few features due to the bound ligands. Within the CT complexes, intensity enhancement for the isoalloxazine ring vibrations is typically 1–2 orders of magnitude and is greatest for vibrations associated with the N5—C4a—C10a—N1 region of the ring. This identifies the region of the isoalloxazine ring that receives the charge transfer from the ligand and confirms, at the same time, that this region is a prime candidate for nucleophilic attack or electron transfer in any reaction scheme. Intensity enhancements for the ligand modes are much higher, typically a few thousand‐fold. Isotopic substitutions combined with quantum mechanical and vibrational calculations were used to identify the ligand modes showing high intensity enhancement. For MTA and MSA these are the methyl symmetric bending and methylene wag. For PCA the pyrrole ring CH deformations show the highest intensity enhancement. Copyright © 2001 John Wiley & Sons, Ltd.
Thiacalixarene self‐assembled monolayers on roughened gold surfaces and their potential as SERS‐based chemical sensors
Authors: Marenco Claudia , Stirling Charles J. M. , Yarwood Jack 
Published: August 2002

AbstractWe report the development of a chemical sensor dependent on self‐assembled monolayers of a thiacalixarene on rough quartz–silica–gold surfaces. The calixarene assemblies were shown to display surface‐enhanced Raman spectroscopic (SERS) signals from ‘adsorbed’ (host–guest intercalates) analyte molecules from dilute aqueous solutions (down to 10−3 M). The response was used to demonstrate the sensing potential of both uncovered and functionalized surfaces for benzene, toluene, alkylbenzenes and benzonitrile. Sensitivity was limited by saturation effects in the millimolar region and the signal‐to‐noise ratios achievable at lower concentrations. Selectivity was demonstrated for benzene vs toluene and benzene vs benzonitrile mixtures. Although detailed elucidation of the analyte surface interactions was not attempted, both reversibility and selectivity appear to be better on the functionalized (rather than on the bare) surfaces. Copyright © 2001 John Wiley & Sons, Ltd.