bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute administration of cocaine regulates the phosphorylation of serine‐19, ‐31 and ‐40 in tyrosine hydroxylase
Authors: Jedynak Jakub P. , Ali Syed F. , Haycock John W. , Hope Bruce T. 
Published: March 2003

AbstractAcute cocaine can inhibit catecholamine biosynthesis by regulating the enzymatic activity of tyrosine hydroxylase via alterations in the phosphorylation state of the enzyme. The mechanisms underlying acute cocaine‐dependent regulation of tyrosine hydroxylase phosphorylation have not been determined. In this study, 0, 15 or 30 mg/kg cocaine was administered intraperitoneally to rats and the phosphorylation state of tyrosine hydroxylase in the brain was examined using antibodies specific for the phosphorylated forms of serine‐19, ‐31 and ‐40 in tyrosine hydroxylase. In the caudate and nucleus accumbens, cocaine dose‐dependently decreased the levels of phosphorylated serine‐19, ‐31 and ‐40. In the ventral tegmental area, the levels of phosphorylated serine‐19, but not serine‐31 and ‐40, were decreased by 15 and 30 mg/kg cocaine. In the amygdala, the levels of phosphorylated serine‐19, but not serine‐31 or ‐40, were decreased. The functional effects of these alterations in phosphorylation state were assessed by measuring tyrosine hydroxylase activityin vivo(accumulation of DOPA after administration of the decarboxylase inhibitor NSD‐1015). Acute administration of 30 mg/kg cocaine significantly decreasedl‐DOPA production in caudate and accumbens but not in amygdala. These data suggest that the phosphorylation of serine‐31 or ‐40, but not serine‐19, is involved in the regulation of tyrosine hydroxylase activity by acute cocaine.
Prominent Narp expression in projection pathways and terminal fields
Authors: Reti Irving M. , Reddy Radhika , Worley Paul F. , Baraban Jay M. 
Published: March 2003

AbstractNarp (neuronal activity regulated pentraxin) is a secreted immediate early gene product that is induced by synaptic activity. Recent studies have indicated that Narp may be an extracellular aggregating factor for AMPA receptors. Immunohistochemical studies have revealed prominent expression of Narp in the mossy fiber pathway of the dentate gyrus, suggesting it may be released pre‐synaptically. However, invitro studies using recombinant Narp indicate that Narp may act when expressed by either pre‐ or post‐synaptic elements. To help define Narp's mode of action, we have examined its localization in the habenula‐interpeduncular pathway which also displays robust Narp expression. Focusing on this pathway as well as hippocampal and cortical Narp expression, we found prominent Narp staining in projection pathways and terminal fields. In contrast, Narp expression in dendrites was minimal in these neuronal populations. These findings indicate that, under physiological conditions, Narp is targeted to the synapse from pre‐ rather than post‐synaptic elements. Our results also suggest that future studies focusing on these projection pathways that express high levels of Narp, in vivo, may help to understand the regulation and function of endogenous Narp.
Failure of the interaction between presenilin 1 and the substrate of γ‐secretase to produce Aβ in insect cells
Authors: Pitsi Didier , Kienlen‐Campard Pascal , Octave Jean‐Noël 
Published: March 2003

AbstractAggregates of β‐amyloid peptide (Aβ) are the major component of the amyloid core of the senile plaques observed in Alzheimer's disease (AD). Aβ results from the amyloidogenic processing of its precursor, the amyloid precursor protein (APP), by β‐ and γ‐secretase activities. If β‐secretase has recently been identified and termed BACE, the identity of γ‐secretase is still obscure. Studies with knock‐out mice showed that presenilin 1 (PS1), of which mutations are known to be the first cause of inherited AD, is mandatory for the γ‐secretase activity. However, the proteolytic activity of PS1 remains a matter of debate. Here we used transfected Sf9 insect cells, a cellular model lacking endogenous β‐ and/or γ‐secretase activities, to characterize the role of BACE and PS1 in the amyloidogenic processing of human APP. We show that, in Sf9 cells, BACE performs the expected β‐secretase cleavage of APP, generating C99. We also show that C99, which is a substrate of γ‐secretase, tightly binds to the human PS1. Despite this interaction, Sf9 cells still do not produce Aβ. This strongly argues against a direct proteolytic activity of PS1 in APP processing, and points toward an implication of PS1 in trafficking/presenting its substrate to the γ‐secretase.
Adenosine A2a receptor‐mediated inhibition of rod opsin mRNA expression in tiger salamander
Authors: Alfinito Peter D. , Alli Roshni , Townes‐Anderson Ellen 
Published: March 2003

AbstractThe neuromodulator adenosine mediates dark‐adaptive changes in retinal photoreceptors through A2a receptors. In cold‐blooded vertebrates, opsin mRNA expression is lower at night than during the day. In the present study, we tested whether adenosine could inhibit opsin mRNA expression in cultured rod cells and if endogenous adenosine acts to suppress opsin mRNA in the intact retina at night. Semi‐quantitative in situ hybridization showed that treatment with 100 nm of the A2a/A2b agonist N 6‐[2‐(3,5‐dimethoxyphenyl)‐2‐(2‐methylphenyl)‐ethyl]adenosine (DPMA) reduced opsin mRNA 41% in cultured rod cells. The effect of DPMA was blocked by 10 µm of the A2a antagonist 8‐(3‐chlorostyryl)caffeine (CSC) but not by 10 µm of the A2b antagonist alloxazine. One micromolar adenosine alone had no effect on opsin mRNA. However, in the presence of the adenosine deaminase inhibitor erythro‐9‐(2‐hydroxy‐3‐nonyl)adenine hydrochloride (EHNA), 1 µm adenosine reduced opsin mRNA 61%. EHNA alone reduced opsin mRNA by 26%. Consistent with an A2a receptor mechanism, 100 nm forskolin (adenylate cyclase agonist) decreased opsin mRNA 34%. Finally, northern blots showed that intravitreal injection of 10 µm CSC at night increased opsin I mRNA 38%. Thus, endogenous adenosine suppresses rod opsin I mRNA expression at night; in vitro results indicate this reduction occurs through A2a‐like receptor binding and stimulation of adenylate cyclase activity.
Urotensin‐II regulates intracellular calcium in dissociated rat spinal cord neurons
Authors: Filipeanu Catalin M. , Brailoiu Eugen , Le Dun Siok , Dun Nae J. 
Published: March 2003

AbstractUrotensin‐II (U‐II), a peptide with multiple vascular effects, is detected in cholinergic neurons of the rat brainstem and spinal cord. Here, the effects of U‐II on [Ca2+]i was examined in dissociated rat spinal cord neurons by fura 2 microfluorimetry. The neurons investigated were choline acetyltransferase‐positive and had morphological features of motoneurons. U‐II induced [Ca2+]i increases in these neurons with a threshold of 10−9 m, and a maximal effect at 10−6 m with an estimated EC50 of 6.2 × 10−9 m. The [Ca2+]i increase induced by U‐II was mainly caused by Ca2+ influx from extracellular space, as the response was markedly attenuated in a Ca2+‐free medium. Omega‐conotoxin GVIA (10−7 m), a N‐type Ca2+ channel blocker, largely inhibited these increases, whereas the P/Q Ca2+ channel blocker, omega‐conotoxin GVIIC (10−7 m) and the l‐type Ca2+ channel blocker, verapamil (10−5 m) had minimal effects. Down‐regulation of protein kinase C by 4‐α‐phorbol 12‐myristate 13‐acetate (10−6 m) or enzyme inhibition using the specific inhibitor bisindolylmaleimide I (10−6 m) did not inhibit the observed effects. Similarly, inhibition of protein kinase G with KT5823 (10−6 m) or Rp‐8‐pCPT‐cGMPS (3 × 10−5 m) did not modify U‐II‐induced [Ca2+]i increases. In contrast, protein kinase A inhibitors KT5720 (10−6 m) and Rp‐cAMPS (3 × 10−5 m) reduced the response to 25 ± 3% and 42 ± 8%, respectively. Present results demonstrate that U‐II modulates [Ca2+]i in rat spinal cord neurons via protein kinase A cascade.
Microarray analysis of selected genes in neural stem and progenitor cells
Authors: Luo Yongquan , Cai Jingli , Liu Ying , Xue Haipeng , Chrest Francis J. , Wersto Robert P. , Rao Mahendra 
Published: March 2003

AbstractTo access and compare gene expression in fetal neuroepithelial cells (NEPs) and progenitor cells, we have used microarrays containing approximately 500 known genes related to cell cycle regulation, apoptosis, growth and differentiation. We have identified 152 genes that are expressed in NEPs and 209 genes expressed by progenitor cells. The majority of genes (141) detected in NEPs are also present in progenitor populations. There are 68 genes specifically expressed in progenitors with little or no expression in NEPs, and a few genes that appear to be present exclusively in NEPs. Using cell sorting, RT–PCR, in situ hybridization or immunocytochemistry, we have examined the segregation of expression to neuronal and glial progenitors, and identified several that appeared to be enriched in neuronal (e.g. CDK5, neuropilin, EphrinB2, FGF11) or glial (e.g. CXCR4, RhoC, CD44, tenascin C) precursors. Our data provide a first report of gene expression profiles of neural stem and progenitor cells at early stages of development, and provide evidence for the potential roles of specific cell cycle regulators, chemokines, cytokines and extracellular matrix molecules in neural development and lineage segregation.
Mutant prion protein‐mediated aggregation of normal prion protein in the endoplasmic reticulum: implications for prion propagation and neurotoxicity
Authors: Gu Yaping , Verghese Susamma , Mishra Ravi Shankar , Xu Xeumin , Shi Yongchang , Singh Neena 
Published: March 2003

AbstractFamilial prion disorders are believed to result from spontaneous conversion of mutant prion protein (PrPM) to the pathogenic isoform (PrPSc). While most familial cases are heterozygous and thus express the normal (PrPC) and mutant alleles of PrP, the role of PrPC in the pathogenic process is unclear. Plaques from affected cases reveal a heterogeneous picture; in some cases only PrPM is detected, whereas in others both PrPC and PrPM are transformed to PrPSc. To understand if the coaggregation of PrPC is governed by PrP mutations or is a consequence of the cellular compartment of PrPM aggregation, we coexpressed PrPM and PrPC in neuroblastoma cells, the latter tagged with green fluorescent protein (PrPC–GFP) for differentiation. Two PrPM forms (PrP231T, PrP217R/231T) that aggregate spontaneously in the endoplasmic reticulum (ER) were generated for this analysis. We report that PrPC–GFP aggregates when coexpressed with PrP231T or PrP217R/231T, regardless of sequence homology between the interacting forms. Furthermore, intracellular aggregates of PrP231T induce the accumulation of a C‐terminal fragment of PrP, most likely derived from a potentially neurotoxic transmembrane form of PrP (CtmPrP) in the ER. These findings have implications for prion pathogenesis in familial prion disorders, especially in cases where transport of PrPM from the ER is blocked by the cellular quality control.
Identification of an amino acid sequence within GABAA receptor β3 subunits that is important for receptor assembly
Authors: Ehya Noosha , Sarto Isabella , Wabnegger Leila , Klausberger Thomas , Sieghart Werner 
Published: March 2003

AbstractGABAA receptors are chloride ion channels that can be opened by GABA, the most important inhibitory transmitter in the CNS. In the mammalian brain the majority of these pentameric receptors is composed of two α, two β and one γ subunit. To achieve the correct order of subunits around the pore, each subunit must form specific contacts via its plus (+) and minus (–) side. To identify a sequence on the β3 subunit important for assembly, we generated various full‐length or truncated chimeric β3 constructs and investigated their ability to assemble with α1 and γ2 subunits. It was demonstrated that replacement of the sequence β3(76–89) by the homologous α1 sequence impaired assembly with α1 but not with γ2 subunits in α1β3γ2‐GABAA receptors. Other experiments indicated that assembly was impaired via the β3(–) side of the chimeric subunit. Within the sequence β3(76–89) the sequence β3(85–89) seemed to be of primary importance for assembly with α1 subunits. A comparison with the structure of the acetylcholine‐binding protein supports the conclusion that the sequence β3(85–89) is located at the β3(–) side and indicates that it contains amino acid residues that might directly interact with the (+) side of the neighbouring α1 subunit.
Peptidase activities of the 20/26S proteasome and a novel protease in human brain
Authors: Vigouroux Sophie , Furukawa Yoshiaki , Farout Luc , J. Kish Stephen , Briand Marièle , Briand Yves 
Published: March 2003

AbstractMany neurodegenerative diseases are characterized by ubiquitin‐positive protein aggregates or inclusion bodies. Ubiquitin‐conjugated proteins are degraded by the 20/26S proteasome, and reduced proteasome peptidase activities in brain homogenates have been reported in pathologic lesions of Parkinson's and Alzheimer's diseases. However, it is unknown whether crude extracts of human brain contain other proteases having peptidase activities. We found a novel protease of molecular weight of approximately 105 kDa in normal human brain, which exhibited trypsin‐like (T‐L) and chymotrypsin‐like (ChT‐L) activities (corresponding to 52% and 21% of the total activities in crude extracts) but not peptidyl glutamyl peptide hydrolase activity. Both T‐L and ChT‐L activities of this protease were partially inhibited by proteasome inhibitors (MG132, lactacystin) and, in contrast to those of the proteasome, also by sodium dodecyl sulfate. A simple method to obtain a brain fraction specific to the 20/26S proteasome was developed. Our human brain data suggest that T‐L and ChT‐L activity levels of the proteasome reported previously may include those of the 105 kDa protease, an enzyme of as yet unknown biological significance, and that it is necessary to separate the proteasome from this protease to evaluate the actual status of the ubiquitin‐proteasome system in neurodegenerative disorders.
Somatostatin receptors (sst2) are coupled to Go and modulate GTPase activity in the rabbit retina
Authors: Vasilaki Anna , Georgoussi Zafiroula , Thermos Kyriaki 
Published: March 2003

AbstractThe role of somatostatin and its mechanism of action in the retina remains an important target for investigation. Biochemical and pharmacological studies were engaged to characterize the somatostatin receptors in the rabbit retina, and their coupling to G‐proteins. The ability of selective ligands to inhibit [125I]Tyr11‐somatostatin‐14 binding to rabbit retinal membranes was examined. The sst2 analogues SMS201–995, MK678, and BIM23014, displayed IC50 values of 0.28 ± 0.12, 0.04 ± 0.01 and 1.57 ± 0.39 nm, respectively. The sst1 analogue CH275 moderately displaced the [125I]Tyr11‐somatostatin‐14 binding, while selective analogues for sst3, sst4 and sst5 had minimal effect. Immunoblotting and/or immunohistochemistry studies revealed the presence of the pertussis toxin sensitive Gi1/2, and Go proteins, as well as Gs. Somatostatin‐14 and MK678 stimulated GTPase activity in a concentration‐dependent manner with EC50 values of 42.8 ± 16.8 and 70.0 ± 16.5 nm, respectively, thus supporting the functional coupling between the receptor and the G‐proteins. CH275 stimulated the GTPase activity moderately, in agreement with its binding profile. The antisera raised against Goα and Gi1/2α inhibited the somatostatin‐induced high‐affinity GTPase activity, but only anti‐Goα inhibited the MK678 stimulation of the enzyme. These results suggest that somatostatin mediates its actions in the rabbit retina by interacting mainly with sst2 receptors that couple to Goα.
Conditions for rehabilitation of older patients with dementia and hip fracture – the perspective of their next of kin
Authors: Hedman Ann‐Marie Rydholm , Grafström Margareta 
Published: March 2003

Conditions for rehabilitation of older patients with dementia and hip fracture – the perspective of their next of kin The aim of this study was to describe the conditions for rehabilitation of older patients with dementia and hip fracture from the perspective of their next of kin. Twenty patients at orthopaedic wards were examined postfracture using a short cognitive test. The same number of next of kin answered four open‐ended questions about rehabilitation as well as about the patient’s physical function. Qualitative content analysis was used to identify categories. The findings indicate that the conditions for rehabilitation of older patients with dementia and hip fracture are related to the patients’ competence, specific needs of support in the light of competence, environmental factors and classification of the rehabilitation activities. The study confirms that the conditions for rehabilitation are related to symptoms of dementia disease and arise from a decline in competence making the patient unable to cope with the environmental pressure and to perform rehabilitation activities. Because of difficulties in assessing competence, patients with dementia are being judged as incapable of managing rehabilitation. A supportive strategy is necessary to encourage the recovery process.
The woven fabric – a metaphor of nursing care: the major subject in nursing education
Authors: Asp Margareta , Fagerberg Ingegerd 
Published: March 2003

The woven fabric – a metaphor of nursing care: the major subject in nursing education Society's future needs regarding health care present challenges to traditional nursing education. Today, the ambition is to create a nursing role that is appropriate to people's health care needs rather than the needs of the health care system. In nursing education, the major subject – nursing care – is central. Accordingly, there is a need for a consistent and clear articulation of this subject as well as the nursing profession. The aim of the present study was to interpret and describe the major subject, its content and structure in the nursing programme at Mälardalen University. With a hermeneutic approach an interpretation and application emerged as a metaphor of nursing care – the woven fabric. In this structure concepts function as bridges linking theory and practice, whereby it is possible to integrate different aspects of knowledge in order to think, feel and act nursing care.
Decision‐making in the treatment of elderly people: a cross‐cultural comparison between Swedish and German physicians and nurses
Authors: Richter Jörg , Eisemann Martin R. , Bauer Barbara , Kreibeck Hannelore , Åström Sture 
Published: March 2003

Decision‐making in the treatment of elderly people: a cross‐cultural comparison between Swedish and German physicians and nurses The aim of the study was to evaluate the comparability of decisions in the treatment of severely ill incompetent elderly patients among physicians and nurses from a cross‐cultural perspective. Convenience samples of 192 doctors and 182 nurses from Germany and 104 doctors and 122 nurses from Sweden have been investigated by a questionnaire in a cross‐sectional study. Between 39 and 58% of the subjects in the various groups have chosen treatment options, which are not consistent with the patient's will. However, nurses showed a significantly higher compliance than doctors. The probability of choosing cardio‐pulmonary resuscitation decreased with increasing information about the patient's wish. Ethical concerns and the patient's wishes appeared as the most important determinants of treatment decisions, whereas the hospital costs as well as the physicians' religion were of minor importance. The inconsistencies concerning decision‐ making within and between the groups reflect differences in underlying values and lack of societal consensus, which represent a prerequisite for the improvement of patient autonomy. To focus more frequently and to a larger extent onto the problems related to the treatment of severely ill elderly patients as well as onto the training of communication skills with an orientation towards informed consent in the medical training seems to be warranted.
Validity and reliability of the Nursing Minimum Data Set for the Netherlands (NMDSN)
Authors: Goossen William , Dassen Theo , Dijkstra Ate , Hasman Arie , Tiesinga Lucas , Van Den Heuvel Wim 
Published: March 2003

The Nursing Minimum Data Set for the Netherlands (NMDSN) describes nursing care based on nursing phenomena, interventions and outcomes. The validity and reliability of its data collection has not been tested yet. Purpose:  To report about the discriminative validity and the interrater reliability of the NMDSN. Design:  Data were collected in an intensive care ward, in a nursing home and in a residential home. The unit of measurement and analysis is the ‘patient day’. The analysis for validity consisted of ridits calculations, and their graphical representations. Interrater reliability was measured by percentage agreement and Cohen's kappa. Results:  Graphs illustrate the differences on most nursing phenomena and interventions as expected beforehand. The percentage agreements for the residential home vary from 60.4 to 100%, and the kappa statistics from −0.09 to 0.85, indicating a poor to almost perfect interrater reliability. Conclusion:  Intensive care patients and patients in the nursing home have more problems and need more nursing interventions compared with general hospital patients, while the patients in the residential home have lesser of both. This illustrates the discriminative validity of the NMDSN. The kappa values for various NMDSN variables are sufficient. A similar test in the general hospital is recommended.
PCR primers for polymorphic microsatellite loci in the facultatively polygynous plant‐antPetalomyrmex phylax(Formicidae)
Authors: Dalecky A. , Debout G. , Mondor G. , Rasplus J.‐Y. , Estoup A. 
Published: March 2003

AbstractFourteen microsatellite loci were isolated and their level of polymorphism characterized in two populations of the facultatively polygynous plant‐antPetalomyrmex phylax(Formicinae). High levels of within‐population variation were observed at most loci, with number of alleles ranging from two to 15, and heterozygosity from 0.050 to 0.925. Cross‐species amplification of these loci was also tested in four plant‐ant species belonging to three other genera,Aphomomyrmex,Cladomyrma (both Formicinae) andCataulacus(Myrmicinae).
Isolation and characterization of polymorphic microsatellite DNA markers in two shrew species, Sorex unguiculatus and S. caecutiens
Authors: Naitoh Y. , Ishibashi Y. , Abe S. , Ohdachi S. D. 
Published: March 2003

AbstractWe isolated six microsatellite markers from the partial genomic libraries of two Sorex shrews, S. unguiculatus and S. caecutiens, and examined their allelic variation. All loci showed high allelic variation ranging from 15 to 19 alleles and all but one locus conformed to Hardy–Weinberg expectations in the species where the loci were isolated. Cross‐species amplifications showed that all primers derived from S. unguiculatus were useful for S. caecutiens, while among primer sets derived from S. caecutiens only one was useful for S. unguiculatus. Accordingly, at least five microsatellite markers were useful in S. caecutiens and three in S. unguiculatus.
Characterization of tetranucleotide microsatellite loci in a Lake Victorian, haplochromine cichlid fish: a Pundamilia pundamilia × Pundamilia nyererei hybrid
Authors: Taylor Martin I. , Meardon Fiona , Turner George , Seehausen Ole , Mrosso Hilary D. J. , Rico Ciro 
Published: March 2003

AbstractThe haplochromine cichlid fishes inhabiting Lake Victoria in East Africa are of great interest to evolutionary biologists. We have isolated and optimized six tetranucleotide and a single dinucleotide locus from a hybrid of the haplochromine cichlid fishes, Pundamilia pundamilia and P. nyererei. Characterization in 18 individuals of P. nyererei from a single wild population revealed between six and 18 alleles per locus, with expected heterozygosity ranging from 0.68 to 0.94. These loci will prove useful for investigations of population structure, and elucidating relationships between closely related species. An additional 26 unoptimized loci have been deposited with GenBank and the MEN database.