bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative determination of the human MRP1 and MRP2 mRNA expression in FACS‐sorted peripheral blood CD4+, CD8+, CD19+, and CD56+cells
Authors: Oselin Kersti , Mrozikiewicz Przemyslaw M. , Pähkla Rein , Roots Ivar 
Published: July 2003

Abstract:Objectives: ATP‐binding cassette (ABC) transporters extrude a wide variety of endogenous and exogenous compounds. In cancer cells, they are known to confer multidrug resistance. The aim of the present study was to determine the expression of the multidrug resistance‐associated protein 1 (MRP1) and 2 (MRP2), which are members of the subfamily C of the ABC transporters family, in human hematopoietic cells.Methods: CD4+, CD8+, CD19+, and CD56+ cells were isolated from whole blood by FACS‐sort in 20 healthy volunteers. MRP1 and MRP2 mRNA levels were quantified using real‐time reverse transcriptase–polymerase chain reaction (RT–PCR) assays on a LightCyclerTM (Roche, Mannheim, Germany).Results: The MRP1 mRNA exhibited the highest abundance in CD4+ cells (7.4 × 103 ± 3.19 × 103 molecules/ng of total RNA), followed by CD8+ > CD19+ > CD56+ cells. The MRP2 mRNA expression was highest in CD4+ cells (6.7 × 102 ± 2.84 × 102), followed by CD8+ > CD56+ > CD19+ cells. No correlation between the MRP1 and MRP2 mRNA expression was observed. Interestingly, β2‐microglobulin mRNA expression in CD19+ cells was found to be twofold lower in comparison with other cells.Conclusions: On an mRNA level both MRP1 and MRP2 were expressed in peripheral blood cells, with more than sevenfold higher MRP1 expression in all cell populations investigated. The impact of the MRP1 and MRP2 transcription in these cells remains to study. The use of β2‐microglobulin as a housekeeping gene could have a critical impact on the interpretation of RT–PCR data.
Conservation of the syntenies between porcine chromosome 7 and human chromosomes 6, 14 and 15 demonstrated by radiation hybrid mapping and linkage analysis
Authors: Tanaka M. , Matsumoto T. , Yanai S. , Domukai M. , Toki D. , Hayashi T. , Kiuchi S. , Yasue H. , Uenishi H. , Kobayashi E. , Awata T. 
Published: July 2003

SummaryComparative mapping studies facilitate the identification of genes located in quantitative trait locus (QTL) regions in domestic animals by utilizing information from the human genome. Radiation hybrid (RH) mapping is effective for this purpose because of its high resolution in ordered gene mapping on chromosomes. We constructed an RH map of pig chromosome 7, by adding 23 markers associated with genes. This RH map clearly demonstrated the mosaic of homology between pig chromosome 7 (SSC7) and human chromosomes 6, 14 and 15 at a ‘gene’ level, and was confirmed by linkage analysis. Clarification of the homology of SSC7 to human chromosomes will contribute to the elucidation of the gene(s) responsible for QTL detected on this chromosome.
Chromosome localization of the 31 type I Texas bovine markers in sheep and goat chromosomes by comparative FISH‐mapping and R‐banding
Authors: Di Meo G. P. , Perucatti A. , Gautier M. , Hayes H. , Incarnato D. , Eggen A. , Iannuzzi L. 
Published: July 2003

SummaryBovine BAC clones containing the 31 genes, referred to as the Texas markers used earlier to definitively assign the 31 bovine syntenic groups (U) to cattle chromosomes, were mapped by fluorescent in situ hybridization to sheep and goat R‐banded chromosomes according to ISCNDB2000. All 31 markers were localized on homoeologous chromosomes and chromosome bands of the two species in agreement with previous localizations obtained both in cattle and river buffalo, definitively confirming chromosome homoeologies between Caprinae and Bovinae. In addition, we have extended physical maps of sheep and goat as 11 genes (HSD3B1, INHBA, CSN10, IGF2R, PIGR, MAP1B, DSC1, ELN, TNFRSF6, CGN1, IGF2) and 14 genes (SOD1, HSD3B1, CSN10, IGF2R, RB1, TG, PIGR, MAP1B, IGH@, LTF, DSC1, TNFRSF6, CGN1, IGF2) were assigned for the first time to goat and sheep chromosomes, respectively.
Association of transforming growth factor β genes with quantitative trait loci for antibody response kinetics in hens
Authors: Zhou H. , Lamont S. J. 
Published: July 2003

SummaryAntibody responses (primary and secondary phases) were measured in an F2 population. The resource population was derived from grandsires of two highly inbred major histocompatibility complex (MHC)‐congenic Fayoumi chicken lines (named M5.1 and M15.2) mated with highly inbred Leghorn G‐B1 hens. Secondary phase parameters of maximum titres (Ymax) and time required to achieve Ymax (Tmax) were estimated from post‐secondary titres by using a non‐linear regression model. Associations of single nucleotide polymorphisms (SNP) in transforming growth factor β2 (TGFB2), 3, and 4 genes with antibody response parameters were evaluated. Multiple immune response parameters were significantly associated with the TGFB2 gene primarily in the lineage of the M5.1 grandsire, suggesting that TGFB2 or linked genes affect antibody response in hens. Significant main effects of the three genes were mostly found in the lineage of the M5.1 grandsire. Significant two‐way interactions on antibody response were primarily detected between TGFB3 and TGFB4 genes, and in the lineage of the M15.2 grandsire. Effects preferentially detectable in only one of the MHC‐congenic lineages suggest that there was interaction between the MHC and TGFB genes. The characterized TGFB SNPs might be applied in marker‐assisted selection to improve antibody production.
Clinical significance of lipoprotein(a) in carotid plaque types and ischemic stroke in the elderly
Authors: Iwamoto Toshihiko , Feng Yi , Shinozaki Kazushi , Koyama Shun‐ichi , Oyama Tetsuo , Takasaki Masaru 
Published: July 2003

Background:  The relationship between lipoprotein(a) (Lp(a)) and ischemic stroke is still controversial in the elderly. The purpose of the present paper was to evaluate the significance of Lp(a) in the development of extracranial carotid lesions and ischemic stroke.Methods:  A total of 371 elderly subjects, studied with carotid ultrasonography (US) and brain computed tomography (CT), was stratified into two groups according to serum Lp(a) levels: the normal Lp(a) and high Lp(a) (>40 mg/dL) groups. Carotid plaques were divided into three types based on the US echogenicity: hypoechoic, hyperechoic, and heterogeneous plaques. Low‐density areas (LDA) on brain CT images were classified into three groups depending on their distribution: basal ganglionic, cortical and only leuko‐araiosis types.Results:  The incidence of bilateral carotid lesions and the ratios of hypoechoic and heterogeneous plaques were significantly higher in the high Lp(a) group than in the normal Lp(a) group. Both the mean height and length of plaque were also greater in the high Lp(a) group. Mean Lp(a) levels were significantly elevated in cases with hypoechoic and heterogeneous types, compared to the cases without lesions. Higher mean Lp(a) levels were seen in cases with any kind of LDA than in normal subjects on CT, but there was no significant difference in the incidence of each LDA between the two groups.Conclusions  These findings indicate that serum Lp(a) is strongly related to carotid lesions, especially hypoechoic and heterogeneous plaque types, in Japanese elderly patients. This suggests that Lp(a) could promote the formation of lipid‐rich atheromatous plaque with intraplaque hemorrhage or superimposed thrombi. Serum Lp(a) also seemed to be a risk for all types of LDA.
Improved reversal learning and altered fear conditioning in transgenic mice with regionally restricted p25 expression
Authors: Angelo Marco , Plattner Florian , Irvine Elaine E. , Giese K. Peter 
Published: July 2003

AbstractCleavage of the cyclin‐dependent kinase 5 activator p35 generates the protein fragment p25, which accumulates in the forebrain of patients with Alzheimer's disease. Although p25 expression has been suggested to affect learning and memory, this hypothesis has not been tested to date. To investigate the role of p25 in hippocampus‐dependent learning and memory we have generated transgenic mice expressing p25 preferentially in postnatal forebrain. p25 expression was highest in hippocampus where it averaged approximately 33% of endogenous p35 expression. This low level of p25 expression did not seem to result in hyperphosphorylation of tau, but increased the phosphorylation of neurofilament M and enhanced the expression of tau protein. These molecular changes did not correlate with neurodegeneration or motor abnormalities. In the Morris water maze the p25 mutants were normal in learning an initial platform location, but surprisingly reversal learning was improved when the platform position was changed. The p25 mutants were normal in contextual fear conditioning. However, when trained with a tone presentation the mutants showed reduced contextual conditioning and enhanced tone fear conditioning. We conclude that low p25 expression has pleiotropic effects on learning and memory. As p25 expression can improve learning and memory, p25 formation could be a compensatory mechanism for learning and memory deficits in Alzheimer's disease.
Enabling role of adenosine A1receptors in adenosine A2Areceptor‐mediated striatal expression ofc‐fos
Authors: Karcz‐Kubicha Marzena , Quarta Davide , Hope Bruce T. , Antoniou Katerina , E. Müller Christa. , Morales Marisela , Schindler Charles W. , Goldberg Steven R. , Ferré Sergi 
Published: July 2003

AbstractWhen striatal neurons are strongly activated they produce adenosine, which activates nearby adenosine A1receptors (A1Rs) and adenosine A2Areceptors (A2ARs). Although the effects of A1R or A2AR activation on neural activity in the striatum have been examined separately, the effects of coactivating both receptors has not been investigated. Using c‐Fos immunohistochemistry as an indicator of neural activity, we examined the effects of coactivation of A1Rs and A2ARs on neural activity and their mechanism of interaction in the caudate‐putamen, nucleus accumbens (NAc) and prefrontal cortex in rats. Administration of a motor‐depressant dose of the A2AR agonist CGS 21680 (0.5 mg/kg i.p.) did not significantly inducec‐fosexpression in any of these brain regions. Administration of a motor‐depressant dose of the A1R agonist CPA (0.3 mg/kg, i.p.) produced a small but significant induction ofc‐fosexpression only in the shell of the NAc. Coadministration of CGS 21680 and CPA produced a synergistic induction ofc‐fosexpression in the caudate‐putamen, cingulate cortex, and especially the NAc. In the shell of the NAc administration of CPA significantly decreased extracellular dopamine levels measured byin vivomicrodialysis and blocked CGS 21680‐induced increases in dopamine levels. Because it has been previously shown that activation of dopamine D2receptors (D2Rs) by endogenous dopamine blocks A2AR‐mediatedc‐fosexpression, it is hypothesized that the enabling role of A1Rs in A2AR‐mediated striatalc‐fosexpression is related to the A1R‐mediated inhibition of dopamine release.
Task‐dependent intermanual coupling of 8‐Hz discontinuities during slow finger movements
Authors: Evans Clary M. B. , Baker Stuart N. 
Published: July 2003

AbstractDuring slow finger movements, small discontinuities are visible at approximately 8–10 Hz. We have recorded from eight normal subjects whilst they performed index finger flexion–extension movements with the left and right hand. Movements were either performed in‐phase (both fingers flexing or extending together), or anti‐phase (flexion on one side coinciding with extension on the other). Coherence calculated between left and right finger velocity was significantly above zero at approximately 8 Hz for the in‐phase condition, but was significantly smaller for anti‐phase movements (mean coherence across all subjects at 8.7 Hz was 0.031 for in‐phase, 0.010 for anti‐phase). We also calculated a ‘phase coherence’ measure which, unlike conventional coherence analysis, was sensitive only to phase synchronization and not to amplitude co‐variations. For the in‐phase task, phase coherence values were smaller than coherence, but still significantly different from zero around 8 Hz; for the anti‐phase task, phase coherence was not significant in this band. Measures calculated from EMG recordings yielded similar conclusions to those using finger velocity, indicating that the results were not simply due to mechanical cross‐talk. Neural oscillators generating approximately 8‐Hz movement discontinuities on each side of the body are therefore selectively coupled during the in‐phase task. A wavelet‐based analysis further suggested that intermanual coupling modulated during in‐phase task performance; coupling was maximal at the start and the end of a movement. We conclude that the systems producing approximately 8‐Hz movement discontinuities and those responsible for intermanual coupling are likely to share common neural elements.
Cell type‐dependent expression of HCN1 in the main olfactory bulb
Authors: Holderith Noémi B. , Shigemoto Ryuichi , Nusser Zoltan 
Published: July 2003

AbstractIn many brain regions, hyperpolarization‐activated cationic currents (Ih) are involved in the generation of rhythmic activities, but the role of Ih in olfactory oscillations remains unclear. Knowledge of the cellular and subcellular distributions of hyperpolarization‐activated and cyclic nucleotide‐gated channel (HCN) subunits is necessary for understanding the role of Ih in olfactory network activities. Using light microscopic immunocytochemistry, we demonstrate strong HCN1 labelling of the glomerular layer and moderate staining of granule cell, internal and external plexiform layers of the rat main olfactory bulb. In the glomerular layer, among many unlabelled neurons, two distinct subpopulations of juxtaglomerular cells are labelled. Approximately 10% of the juxtaglomerular cells strongly express HCN1. These small diameter cells are immunoreactive for GABA and comprise a subpopulation of periglomerular cells. An additional subset of juxtaglomerular cells (≈ 1%) expresses low levels of HCN1. They are large in diameter, GABA immunonegative but immunopositive for vesicular glutamate transporter 2, characterizing them as external tufted cells. Quantitative immunogold localization revealed that the somatic plasma membranes of periglomerular cells contain approximately four times more HCN1 labelling than those of external tufted cells. Unlike in cortical pyramidal cells, immunogold density for HCN1 does not significantly differ in somatic and dendritic plasma membranes of external tufted cells, indicating that post‐synaptic potentials arriving at proximal and distal dendrites are modulated by the same density of Ih. Our results demonstrate a cell type‐dependent expression of HCN1 in the olfactory bulb and predict a differential contribution of distinct juxtaglomerular cell types to network oscillations.
Repeated withdrawal from ethanol impairs acquisition but not expression of conditioned fear
Authors: Ripley T. L. , O'Shea M. , Stephens D. N. 
Published: July 2003

AbstractRepeated withdrawal from ethanol impairs acquisition of conditioned fear [Stephens, D.N., Brown, G., Duka, T. & Ripley, T.L. (2001) Eur. J. Neurosci., 14, 2023–2031]. This study further examined the effect of repeated withdrawal from ethanol on the expression and acquisition of fear conditioning. Following training, presentation of a cue associated with footshock (CS+) resulted in a suppression of operant responding for food reinforcement. In different groups, shock thresholds were manipulated to give weak or severe behavioural suppression. Rats were subsequently chronically treated with ethanol‐containing liquid diet either continuously (single withdrawal) or with three withdrawal periods (repeated withdrawal). Ethanol treatment and withdrawal had no effect on conditioned suppression of responding tested 2 weeks after the final withdrawal, at either shock intensity. Nevertheless, extinction of conditioned fear was impaired in the repeated withdrawal group exposed to the higher shock intensity. In the high intensity group, the stimulus–shock association was then reversed, so that the previously neutral conditioned stimulus (CS–) became the CS+. Acquisition of suppression to the new CS+ was significantly less in the animals previously given repeated experience of withdrawal, confirming our previous finding. Thus, repeated withdrawal from ethanol lead to disruption in the acquisition of fear conditioning but had no effect on retrieval of an association formed prior to the ethanol‐withdrawal experiences.
Visual receptive field properties of neurons in the caudate nucleus
Authors: Nagy Attila , Eördegh Gabriella , Norita Masao , Benedek György 
Published: July 2003

AbstractVisual single‐unit activity was recorded in the caudate nucleus of halothane‐anaesthetized, immobilized, artificially respirated cats. Visually sensitive neurons were found in the dorsolateral part of the caudate body. A majority of the units responded optimally to small spot‐like stimuli moving with velocities between 30 and 120 °/s. The receptive field of these units is large: it covers a major part of both the contra‐ and ipsilateral visual hemifields. No signs of retinotopy were observed. Most of the neurons display directional selectivity and are narrowly tuned to the direction of the moving stimulus. These physiological properties are consistent with recent morphological results that reveal multiple connections of the caudate nucleus with the superior colliculus through tecto‐extrageniculo‐thalamic pathways in the mammalian brain.
Unilateral dorsal column and rubrospinal tract injuries affect overground locomotion in the unrestrained rat
Authors: Webb Aubrey A. , Muir Gillian D. 
Published: July 2003

AbstractThe purpose of this study was to determine the importance of the rubrospinal pathway and the ascending components of the dorsal column for overground locomotion in adult, unrestrained rats. The dorsal column (excluding the corticospinal tract), the rubrospinal tract or both were damaged unilaterally in rats at the level of the upper cervical spinal cord. Behavioural analysis consisted of skilled locomotion (an evaluation of footslips during ladder walking), a paw usage task and the assessment of ground reaction forces during unrestrained locomotion. All lesioned animals used the forepaw ipsilateral to the lesions less while rearing. Animals with dorsal column injuries used the forelimb contralateral to the spinal injury significantly more while rearing compared with uninjured animals. All lesioned animals produced more footfalls while crossing the ladder compared with uninjured animals. All injuries, regardless of the pathway affected, resulted in significant alterations in body weight support and reduced braking forces from the forelimb ipsilateral to the injury during overground locomotion. Animals typically bore less weight on the hindlimb ipsilateral to the lesion compared with the hindlimb contralateral to the spinal injury. Taken together with previously published work, our data indicate that the rubrospinal and dorsal column pathways are important for forelimb support while rearing and for skilled locomotion. Additionally, the ascending dorsal column pathways and the rubrospinal tract play a role during flat surface overground locomotion and combined damage to these pathways does not alter the acquired gait.
Identification of circadian brain photoreceptors mediating photic entrainment of behavioural rhythms in lizards
Authors: Pasqualetti Massimo , Bertolucci Cristiano , Ori Michela , Innocenti Augusto , Magnone Maria C. , De Grip Willem J. , Nardi Irma , Foà Augusto 
Published: July 2003

AbstractWe have shown previously that in ruin lizards (Podarcis sicula) the ablation of all known photoreceptive structures (lateral eyes, pineal and parietal eye) in the same individual animal does not prevent entrainment of their circadian locomotor rhythms to light. The present study was aimed at identifying the circadian brain photoreceptors mediating entrainment. For this purpose, we looked for opsin expression in the brain by means of immunocytochemistry. Using anti‐cone‐opsin antiserum CERN 874 we have localized photoreceptors in the periventricular area of hypothalamus, near the third cerebral ventricle. We also cloned a brain opsin cDNA that, on the basis of the deduced amino acid sequence, appears to belong to the RH2 class of cone‐opsins. We named the cloned cone‐opsin Ps‐RH2. To examine whether brain cone‐opsins mediate photic entrainment of circadian locomotor rhythms, we performed post‐transcriptional inactivation experiments by injecting an expression eukaryotic vector transcribing the antisense cone‐opsin Ps‐RH2 mRNA in the third cerebral ventricle of pinealectomized–retinectomized lizards previously entrained to a light–dark (LD) cycle. Injections of the antisense construct abolished photic entrainment of circadian locomotor rhythms of pinealectomized–retinectomized lizards to the LD cycle for 6–9 days. CERN 874 completely failed to label cells within the periventricular area of hypothalamus of brains injected with antisense construct. Thus, abolishment of photic entrainment is due to inactivation of endogenous brain cone‐opsins mRNA. The present results demonstrate for the first time in a vertebrate that brain cone‐opsins are part of a true circadian brain photoreceptor participating in photic entrainment of behavioural rhythms.
Subcellular distribution of L‐type Ca2+ channels responsible for plateau potentials in motoneurons from the lumbar spinal cord of the turtle
Authors: Simon Magda , Perrier Jean‐François , Hounsgaard Jørn 
Published: July 2003

AbstractL‐type calcium channels mediate the persistent inward current underlying plateau potentials in spinal motoneurons. Electrophysiological analysis shows that plateau potentials are generated by a persistent inward current mediated by low threshold L‐type calcium channels located in the dendrites. As motoneurons express L‐type calcium channels of the CaV1.2 and CaV1.3 subtypes, we have investigated the subcellular distribution of these channels using antibody labelling. The plateau generating a persistent inward current is modulated by the activation of metabotropic receptors. For this reason, we also examined the relationship between CaV1.2 and CaV1.3 subunits in motoneurons and presynaptic terminals labelled with antibodies against synapsin 1a. Motoneurons in the spinal cord of the adult turtle were identified as large neurons, immunopositive for choline acetyltransferase, located in the ventral horn. In these neurons, CaV1.2 subunits were present in the cell bodies and axons. Patches of CaV1.3 subunits were seen in association with the cell membrane of the somata and both the proximal and distal dendrites. Double labelling with an antibody against synapsin 1a showed that CaV1.3 subunits, but not CaV1.2 subunits, were always located at synaptic sites. The distribution of CaV1.2 and CaV1.3 strongly suggests that the persistent inward current underlying plateau potentials in spinal motoneurons is mediated by CaV1.3 and not by CaV1.2. Our findings also show that CaV1.3 may be located in the somatic and dendritic membrane adjacent to particular presynaptic terminals.