bluuebunny/crossref_metadata_2025 huggingface dataset:
Protective action of the peroxisome proliferator‐activated receptor‐γ agonist pioglitazone in a mouse model of Parkinson's disease
Authors: Breidert T. , Callebert J. , Heneka M. T. , Landreth G. , Launay J. M. , Hirsch E. C.
Published: March 2003

We examined the effect of pioglitazone, a peroxisome proliferator‐activated receptor‐γ (PPARγ)agonistofthethiazolidinedione class, on dopaminergic nerve cell death and glial activation in the 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) mouse model of Parkinson's disease. The acute intoxication of C57BL/6 mice with MPTP led to nigrostriatal injury, as determined by tyrosine hydroxylase (TH) immunocytochemistry, and HPLC detection of striatal dopamine and metabolites. Damage to the nigrostriatal dopamine system was accompanied by a transient activation of microglia, as determined by macrophage antigen‐1 (Mac‐1) and inducible nitric oxide synthase (iNOS) immunoreactivity, and a prolonged astrocytic response. Orally administered pioglitazone (∼ 20 mg/kg/day) attenuated the MPTP‐inducedglialactivation and prevented the dopaminergic cell loss in the substantia nigra pars compacta (SNpc). In contrast, there was little reduction of MPTP‐induced dopamine depletion, with no detectable effect on loss of TH immunoreactivity and glial response in the striatum of pioglitazone‐treated animals. Low levels of PPARγ expression were detected in the ventral mesencephalon and striatum, and were unaffected by MPTP or pioglitazone treatment. Since pioglitazone affects primarily the SNpc in our model, different PPARγ‐independent mechanisms may regulate glial activation in the dopaminergic terminals compared with the dopaminergic cell bodies after acute MPTP intoxication.
The neuronal choline transporter CHT1 is regulated by immunosuppressor‐sensitive pathways
Authors: Guermonprez Lydie , O'Regan Seana , Meunier François‐Marie , Morot‐Gaudry‐Talarmain Yvette
Published: March 2003

The immunosuppressor cyclosporin A inhibits the peptidyl‐prolyl‐cis/trans‐isomerase activity of cyclophilins and the resulting complex inhibits the phosphatase activity of calcineurin. Both enzymes were detected in peripheral nerve endings isolated from the electric organ of Torpedo and shown to be affected by 10 µm cyclosporin A. Among the cholinergic properties studied, choline uptake was specifically inhibited by cyclosporin A to a maximum of 40%. Cyclosporin A decreased the rate of choline transport but not the binding of the non‐transportable choline analogue hemicholinium‐3, indicating that the number of membrane transporters was not affected. Through the use of two other immunosuppressors, FK506, which also inhibits calcineurin, and rapamycin, which does not, two different mechanisms of choline uptake inhibition were uncovered. FK506 inhibited the rate of choline transport, whereas rapamycin diminished the affinity for choline. The Torpedo homologue of the high affinity choline transporter CHT1 was cloned and its activity was reconstituted in Xenopus oocytes. Choline uptake by oocytes expressing tCHT1 was inhibited by all three immunosuppressors and also by microinjection of the specific calcineurin autoinhibitory domain A457−481, indicating that the phosphatase calcineurin regulates CHT1 activity and could be the common target of cyclosporin and FK506. Rapamycin, which changed the affinity of the transporter, may have acted through an immunophilin on the isomerization of critical prolines that are found in the tCHT1 sequence.
Feasibility of ex vivo gene therapy for neurological disorders using the new retroviral vector GCDNsap packaged in the vesicular stomatitis virus G protein
Authors: Suzuki A. , Obi K. , Urabe T. , Hayakawa H. , Yamada M. , Kaneko S. , Onodera M. , Mizuno Y. , Mochizuki H.
Published: March 2003

Neuronal progenitor cells (NPC) are particularly suited as the target population for genetic and cellular therapy of neurological disorders such as Parkinson's disease or stroke. However, genetic modification of these cells using retroviral vectors remains a great challenge because of the low transduction rate and the need for fetal calf serum (FCS) during the transduction process that induces the cell differentiation to mature neurons. To overcome these problems, we developed a new retrovirus production system in which the simplified retroviral vector GCDNsap engineered to be resistant to denovo methylation was packaged in the vesicular stomatitis virus G protein (VSV‐G), concentrated by centrifugation, and resuspended in serum‐free medium (StemPro‐34 SFM). In transduction experiments using enhanced green fluorescent protein (EGFP) as a marker, the concentrated FCS‐free virus supernatant infected NPC at a high rate, while maintaining the ability of these cells to self‐renew and differentiate in vitro. When such cells were grafted into mouse brains, EGFP‐expressing NPC were detected in the region around the injection site at 8 weeks post transplantation. These findings suggest that the gene transfer system described here may provide a useful tool to genetically modify NPC for treatments of neurological disorders.
Cytochrome c release precedes mitochondrial membrane potential loss in cerebellar granule neuron apoptosis: lack of mitochondrial swelling
Authors: Wigdal Susan S. , Kirkland Rebecca A. , Franklin James L. , Haak‐Frendscho Mary
Published: March 2003

It has been suggested that release of cytochrome c (Cyt c) from mitochondria during apoptotic death is through opening of the mitochondrial permeability transition pore followed by swelling‐induced rupture of the mitochondrial outer membrane. However, this remains controversial and may vary with cell type and model system. We determined that in mouse cerebellar granule neurons, Cyt c redistribution preceded the loss of mitochondrial membrane potential during the apoptotic process, suggesting that the pore did not open prior to release. Furthermore, when mitochondria were morphologically assessed by electron microscopy, they were not obviously swollen during the period of Cyt c release. This indicates that the pore mechanism of action, if any, is not through mitochondrial outer membrane rupture. While bongkrekic acid, an inhibitor of pore opening, modestly delayed apoptotic death, it also caused a significant (p < 0.05) suppression of protein synthesis. An equivalent suppression of protein synthesis by cycloheximide had a similar delaying effect, suggesting that bongkrekic acid was acting non‐specifically. These findings suggest that mitochondrial permeability transition pore is not involved in Cyt c release from mitochondria during the apoptotic death of cerebellar granule neurons.
Putative histamine‐gated chloride channel subunits of the insect visual system and thoracic ganglion
Authors: Witte Ines , Kreienkamp Hans‐Juergen , Gewecke Michael , Roeder Thomas
Published: March 2003

Histamine‐gated chloride channels, members of the ligand‐gated ion channel superfamily, are thought to be peculiar for arthropods. Their cognate ligand, histamine, is the transmitter of all arthropod photoreceptors and of thoracic mechanoreceptors. To identify putative histamine‐gated chloride channel subunits we scanned the Drosophila genome for putative ligand‐gated chloride channel subunits and found 12 candidate genes. We found four groups of transcripts based on their expression pattern. Only members of the last group show an expression pattern that is consistent with our knowledge about histamine‐gated chloride channels in insects. In the brain these transcripts (Dm HA‐Cl I and II) are exclusively present in interneurones postsynaptic to photoreceptors. Within the lamina (the first visual ganglion) only the L1–L3 neurones are labelled. The lack of non‐photoreceptor dependent staining in the brain indicates that mechanosensory transmission differs between the head and the thorax/abdomen, and that the receptors responding to brain‐intrinsic histaminergic cells use different signalling pathways. The putative histamine‐gated chloride channels show the greatest homology mammalian glycine receptors. These ion‐channels are the first specific molecular markers for postsynaptic cells in the insect visual system, thus representing ideal tools to study its physiology and development.
Analysis on the promoter region of exon IV brain‐derived neurotrophic factor in NG108‐15 cells
Authors: Takeuchi Yusuke , Miyamoto Eishichi , Fukunaga Kohji
Published: March 2003

We have reported that the nuclear isoforms of Ca2+/calmodulin‐dependent protein kinase II (CaM KII) are involved in the expression of the exon IV‐containing brain‐derived neurotrophic factor (BDNF) mRNA. We document here the cis‐elements and transcription factors responsive to CaM KII inthe activation of the promoter upstream of the exon IV (exon IV‐BDNF promoter). Effects of constitutively active mutants of CaM KIV, MAPK kinase kinase (MEKK) and protein kinase A (PKA) on the exon IV‐BDNF promoter activity were also evaluated by transfection and luciferase assay. The exon IV‐BDNF promoter activity was increased by transfection with CaM KII, MEKK and PKA, but not by CaM KIV. Deletion and mutational analysis of the promoter revealed that the region between nucleotides −56 and −27 was responsive to CaM KII, which contained a CCAAT‐box in the region between nucleotides −56 and −43. Expression of C/EBPβ increased the promoter activity and potentiated the effects of CaM KII. The region between nucleotides −79 and −56 was responsive to MEKK, in which both a GA‐rich sequence and a GC‐box were included. Expression of Sp1 increased the promoter activity, which was further enhanced by transfection with MEKK. The region between nucleotides −43 and −27 was responsive to both PKA and CaM KII, but the transcription factors involved in the region remained unclear. These results suggest that the promoter of the exon IV‐BDNF is at least regulated by CaM KII, MEKK and PKA, and that C/EBP/β and Sp1 are potential transcription factors activated by CaM KII and MEKK, respectively.
The 5′‐flanking region of the rat GABAA receptor α2‐subunit gene (Gabra2)
Authors: Fuchs Karoline , Celepirovic Nevenka
Published: March 2003

The GABAA receptor α2‐subunit gene (Gabra2) has a specific spatial and temporal pattern of expression in rat brain. As a first step towards understanding the molecular mechanism underlying this regulation, we have investigated the structural properties of the 5′‐ flanking region of the rat Gabra2 gene. We identified six α2 transcript isoforms, each of which differs only in the 5′‐untranslated region (UTR). Alignment of cDNA and genomic DNA sequences revealed that six 5′‐UTRs are generated from three alternative first exons by alternative splicing using internal and terminal 5′‐splice donor sites present in these exons. Promoter regions containing multiple transcription initiation sites were identified in the 5′ proximity of each first exon. Two of these promoters lack TATA and CCAAT sequences. Finally, we have shown that differential activation of alternative promoters is used for the expression of the α2 mRNA isoforms during brain development, and that the diversity at the 5′‐end of these transcripts affects GABAA receptor expression. Taken together, these results suggest that the expression of the Gabra2 gene can be influenced at both the transcriptional and post‐transcriptional levels.
Pyroglutamate‐modified amyloid β‐peptides – AβN3(pE) – strongly affect cultured neuron and astrocyte survival
Authors: Russo Claudio , Violani Elisabetta , Salis Serena , Venezia Valentina , Dolcini Virginia , Damonte Gianluca , Benatti Umberto , D'Arrigo Cristina , Patrone Eligio , Carlo Pia , Schettini Gennaro
Published: March 2003

N‐terminally truncated amyloid‐β (Aβ) peptides are present in early and diffuse plaques of individuals with Alzheimer's disease (AD), are overproduced in early onset familial AD and their amount seems to be directly correlated to the severity and the progression of the disease in AD and Down's syndrome (DS). The pyroglutamate‐containing isoforms at position 3 [AβN3(pE)−40/42] represent the prominent form among the N‐truncated species, and may account for more than 50% of Aβ accumulated in plaques. In this study, we compared the toxic properties, fibrillogenic capabilities, and in vitro degradation profile of Aβ1–40, Aβ1–42, AβN3(pE)−40 and AβN3(pE)−42. Our data show that fibre morphology of Aβ peptides is greatly influenced by the C‐terminus while toxicity, interaction with cell membranes and degradation are influenced by the N‐terminus. AβN3(pE)−40 induced significantly more cell loss than the other species both in neuronal and glial cell cultures. Aggregated AβN3(pE) peptides were heavily distributed on plasma membrane and within the cytoplasm of treated cells. AβN3(pE)−40/42 peptides showed a significant resistance to degradation by cultured astrocytes, while full‐length peptides resulted partially degraded. These findings suggest that formation of N‐terminally modified peptides may enhance β‐amyloid aggregation and toxicity, likely worsening the onset and progression of the disease.
Morphine withdrawal‐induced c‐fos expression in the hypothalamic paraventricular nucleus is dependent on the activation of catecholaminergic neurones
Authors: Laorden M. Luisa , Núñez Cristina , Almela Pilar , Milanés M. Victoria
Published: March 2003

We previously demonstrated that morphine withdrawal induced hyperactivity of noradrenergic pathways innervating the hypothalamic paraventricular nucleus (PVN) in rats, in parallel with an increase in the neurosecretory activity of the hypothalamus–pituitary–adrenocortical (HPA) axis, as evaluated by corticosterone release. These neuroendocrine effects were dependent on stimulation of α‐adrenoceptors. In the present study, Fos immunostaining was used as a reflection of neuronal activity and combined with immunostaining for tyrosine hydroxylase (TH) for immunohistochemical identification of active neurones during morphine withdrawal. Dependence on morphine was induced by 7‐day chronic subcutaneous implantation of six morphine pellets (75 mg). Morphine withdrawal was precipitated by administration of naloxone (5 mg/kgsubcutaneously) on day 8. Fos immunoreactivity in the PVN and also in the nucleus tractus solitarius (NTS)‐A2 and ventrolateral medulla (VLM)‐A1 cell groups, which project to the PVN, increased during morphine withdrawal. Following withdrawal, Fos immunoreactivity was present in most of the TH‐positive neurones of the A2 and A1 neurones. In a second study, the effects of administration of adrenoceptor antagonists on withdrawal‐induced Fos expression in the PVN were studied. Pre‐treatment with α1‐ or α2‐adrenoceptor antagonists, prazosin (1 mg/kg intraperitoneally) and yohimbine (1 mg/kg intraperitoneally), respectively, 20 min before naloxone administration to morphine‐dependent rats markedly reduced Fos expression in the PVN. Similarly, pre‐treatment with the β antagonist, propranolol (3 mg/kg intraperitoneally), significantly prevented withdrawal‐induced Fos expression. Collectively, these results suggest the hypothesis that noradrenergic neurones in the brainstem innervating the PVN are active during morphine withdrawal, and that activation of transcriptional responses mediated by Fos in the HPA axis following withdrawal are dependent upon hypothalamic α‐ and β‐adrenoceptors.
Neurokinin‐1 (NK‐1) receptor antagonists abrogate methamphetamine‐induced striatal dopaminergic neurotoxicity in the murine brain
Authors: Yu Jing , Cadet Jean Lud , Angulo Jesus A.
Published: March 2003

Methamphetamine (METH) is an addictive substance that also causes extensive neural degeneration in the central nervous system. Because METH augments striatal substance P (SP) levels, we hypothesized that this neuropeptide plays a role in methamphetamine‐induced toxicity and neural damage in the striatum. In this study we present evidence demonstrating that signaling through the neurokinin‐1 (NK‐1) receptor by SP plays an important role in methamphetamine‐induced toxicity in the striatum. We tested the effects of the selective NK‐1 receptor antagonists WIN‐51,708 and L‐733,060 on several markers of dopaminergic terminal toxicity in the mouse striatum. Administration of NK‐1 receptor antagonist prevented the loss of dopamine transporters assessed by autoradiography and western blotting, the loss of tissue dopamine assessed by high‐pressure liquid chromatography, and the loss of tyrosine hydroxylase, as well as the induction of glial fibrillary acidic protein determined by western blotting. Pre‐treatment with NK‐1 receptor antagonist had no effect on METH‐induced hyperthermia. Pre‐exposure of mice to either of the NK‐1 receptor antagonists alone was without effect on all of these neurochemical markers. These results provide the first evidence that tachykinins, particularly SP, acting through NK‐1 receptors, play a crucial role in the pathogenesis of nigrostriatal dopaminergic terminal degeneration induced by METH. This finding could lead to novel therapeutic strategies to offset drug addictions as well as in the treatment of a number of disorders including Parkinson's and Huntington's diseases.
Group‐I metabotropic glutamate receptors, mGlu1a and mGlu5a, couple to extracellular signal‐regulated kinase (ERK) activation via distinct, but overlapping, signalling pathways
Authors: Thandi Sukhwinder , Blank Jonathan L. , Challiss R. A. John
Published: March 2003

The coupling of the group I metabotropic glutamate receptors, mGlu1a and mGlu5a, to the extracellular signal‐regulated protein kinase (ERK) pathway has been studied in Chinese hamster ovary cell‐lines where receptor expression is under inducible control. Both mGlu receptors stimulated comparable, robust and agonist concentration‐dependent ERK activations in the CHO cell‐lines. The mGlu1a receptor‐mediated ERK response was almost completely attenuated by pertussis toxin (PTx) pretreatment, whereas the mGlu5a‐ERK response, and the phosphoinositide response to activation of either receptor, was PTx‐insensitive. mGlu1a and mGlu5a receptor coupling to ERK occurred via mechanisms independent of phosphoinositide 3‐kinase activity and intracellular and/or extracellular Ca2+ concentration. While acute treatment with a protein kinase C (PKC) inhibitor did not attenuate agonist‐stimulated ERK activation, down‐regulation of PKCs by phorbol ester treatment for 24 h did attenuate both mGlu1a and mGlu5a receptor‐mediated responses. Further, inhibition of Src non‐receptor tyrosine kinase activity by PP1 attenuated the ERK response generated by both receptor subtypes, but only mGlu1a receptor‐ERK activation was attenuated by PDGF receptor tyrosine kinase inhibitor AG1296. These findings demonstrate that, although expressed in a common cell background, these closely related mGlu receptors utilize different G proteins to cause ERK activation and may recruit different tyrosine kinases to facilitate this response.
Rat MYH, a glycosylase for repair of oxidatively damaged DNA, has brain‐specific isoforms that localize to neuronal mitochondria
Authors: Englander Ella W. , Hu Zhaoyong , Sharma Abha , Lee Heung‐Man , Wu Zhao‐Hui , Greeley George H.
Published: March 2003

Mitochondrial genomes are exposed to a heavy load of reactive oxygen species (ROS) that damage DNA. Since in neurons, mitochondrial DNA integrity must be maintained over the entire mammalian life span, neuronal mitochondria most likely repair oxidatively damaged DNA. We show that theEscherichia coliMutY DNA glycosylase homolog (MYH) in rat (rMYH) involved in repair of oxidative damage is abundantly expressed in the rat brain, with isoforms that are exclusive to brain tissue. Confocal microscopy and western analyses reveal localization of rMYH in neuronal mitochondria. To assess involvement of MYH in the neuronal response to oxidative DNA damage, we used a rat model of respiratory hypoxia, in which acutely reduced blood oxygenation leads to generation of superoxide, and formation and subsequent removal of 8‐hydroxy‐2′‐deoxyguanosine (8OHdG). Removal of 8OHdG is accompanied by a spatial increase in rMYH immunoreactivity in the brain and an increase in levels of one of the three mitochondrial MYH isoforms, suggesting that inducible and non‐inducible MYH isoforms exist in the brain. The mitochondrial localization of oxidative DNA damage repair enzymes in neurons may represent a specialized neuronal mechanism that safeguards mitochondrial genomes in the face of routine and accidental exposures to heavy loads of injurious ROS.
Long‐lasting occupancy of central nicotinic acetylcholine receptors after smoking: a PET study in monkeys
Authors: Valette Héric , Bottlaender Michel , Dollé Frédéric , Coulon Christine , Ottaviani Michèle , Syrota André
Published: March 2003

The aim of this study was to compare the degree of occupancy of central nicotinic acetylcholine receptors (nAChR) in isoflurane anaesthetized baboon brain following inhalation of tobacco smoke (one cigarette containing 0.9 mg nicotine) or i.v. nicotine (0.6 mg i.v.). [18F]Fluoro‐A‐85380 and positron emission tomography (PET) were used to assess the distribution volumes (DV) of the radiotracer in selected brain areas using a one‐compartment model. Eighty minutes after nicotine i.v., DV was reduced by 50 and 66% in the thalamus and putamen, respectively. Six hours after nicotine, a reduction in DV (27% in the thalamus) was still observed. Eighty minutes after inhalation of tobacco smoke, DV was decreased by 52 and 65% in the thalamus and putamen, respectively. Previous PET experiments have demonstrated a short‐lasting interaction of [11C]nicotine with nAChRs. Thus, we hypothesized that a metabolite of nicotine with high affinity and long half‐live (several hours) could bind at nAChRs. Eighty minutes after a high dose of nornicotine (0.5 mg i.v.), DV was reduced by 53 and 31% in thalamus and putamen, respectively. No significant effect was observed following 0.15 mg nornicotine. Therefore, nornicotine could contribute to the long‐lasting occupancy of central nAChRs after smoking.
Synaptic activity induces signalling to CREB without increasing global levels of cAMP in hippocampal neurons
Authors: Pokorska Anna , Vanhoutte Peter , Arnold Fiona J. L. , Silvagno Francesca , Hardingham Giles E. , Bading Hilmar
Published: March 2003

Nuclear calcium signals associated with electrical activation of neurons can control the activity of the transcription factor cAMP‐response element binding protein (CREB). Yet, cAMP is thought to be the key messenger that links synaptic activity to the regulation of CREB‐mediated transcription. It is generally assumed that synaptic activity increases the intracellular levels of cAMP; this causes activation of the cAMP‐dependent protein kinase (PKA) that regulates CREB‐mediated transcription either directly or through controlling nuclear signalling of the MAP kinases/extracellular signal‐regulated kinases (ERK1/2) pathway. Here we show that, in hippocampal neurons, synaptic activity failed to increase global levels of cAMP that would be required for the cAMP‐PKA system to induce nuclear events. Even near‐continuous bursting of action potentials, giving rise to large nuclear calcium signals and robust CREB‐dependent transcription, left global intracellular levels of cAMP unchanged. These results suggest that the cAMP‐PKA system does not function as the transducer of synaptic signals to the nucleus. They indicate that the known inhibitory effects of blockers of PKA on gene expression and long‐lasting plasticity triggered by calcium entry reflect a gating function of basal activity of PKA that renders neurons permissive for nuclear calcium‐regulated, CREB/CBP‐dependent gene expression.
Developmental regulation of nicotinic acetylcholine receptor‐mediated [3H]norepinephrine release from rat cerebellum
Authors: O'Leary K. T. , Leslie F. M.
Published: March 2003

Presynaptic modulation of synaptic transmission is the primary function of central nicotinic acetylcholine receptors (nAChRs) in developing and adult brain. nAChR activation regulates release of various neurotransmitters, including norepinephrine (NA). Given evidence that NA may serve a critical functional role in cerebellar development, we have undertaken studies to determine whether nAChRs modulate NA release in developing cerebellum. In vitro experiments using cerebellar slices examined the effects of nAChR stimulation on release of radiolabeled NA ([3H]NA). Our data indicate the presence of functional nAChRs on NA terminals in immature cerebellum and subsequent developmental regulation of receptor properties. During postnatal week one, the maximally effective dose of nicotine released 35.0 ± 1.2% of cerebellar [3H]NA stores. There was a subsequent decline in maximal nicotine‐stimulated NA release until postnatal day 30, when Emax values were statistically indistinguishable from adult. Although the efficacy of nicotine changed substantially throughout development, EC50 values did not differ significantly (EC50 = 4.4–12.0 µm). Pharmacological analysis indicated that this developmental shift in maximum nicotine effect reflects a change in the properties of the nAChRs. These data support recent findings of a possible functional role of nAChRs in regulating cerebellar ontogeny, and provides further support for the role of NA as a neurotrophic factor during development.
Effect of experimenter‐delivered and self‐administered cocaine on extracellular β‐endorphin levels in the nucleus accumbens
Authors: Roth‐Deri I. , Zangen A. , Aleli M. , Goelman R. G. , Pelled G. , Nakash R. , Gispan‐Herman I. , Green T. , Shaham Y. , Yadid G.
Published: March 2003

β‐endorphin is an endogenous opioid peptide that has been hypothesized to be involved in the behavioral effects of drugs of abuse including psychostimulants. Using microdialysis, we studied the effect of cocaine on extracellular levels of β‐endorphin in the nucleus accumbens, a brain region involved in the reinforcing effects of psychostimulant drugs. Experimenter‐delivered cocaine (2 mg/kg, i.v.) increased extracellular β‐endorphin immunoreactive levels in the nucleus accumbens, an effect attenuated by 6‐hydroxy‐dopamine lesions or systemic administration of the D1‐like receptor antagonist, SCH‐23390 (0.25 mg/kg, i.p.). The effect of cocaine on β‐endorphin release in the nucleus accumbens was mimicked by a local perfusion of dopamine (5 µm) and was blocked by coadministration of SCH‐23390 (10 µm). Self‐administered cocaine (1 mg/kg/infusion, i.v.) also increased extracellular β‐endorphin levels in the nucleus accumbens. In addition, using functional magnetic resonance imaging, we found that cocaine (1 mg/kg, i.v.) increases regional brain activity in the nucleus accumbens and arcuate nucleus. We demonstrate an increase in β‐endorphin release in the nucleus accumbens following experimenter‐delivered and self‐administered cocaine mediated by the local dopaminergic system. These findings suggest that activation of the β‐endorphin neurons within the arcuate nucleus–nucleus accumbens pathway may be important in the neurobiological mechanisms underlying the behavioral effects of cocaine.
Compounds acting at the endocannabinoid and/or endovanilloid systems reduce hyperkinesia in a rat model of Huntington's disease
Authors: Lastres‐Becker Isabel , De Miguel Rosario , De Petrocellis Luciano , Makriyannis Alexandros , Di Marzo Vincenzo , Fernández‐Ruiz Javier
Published: March 2003

We have recently reported that the administration of AM404, an inhibitor of the endocannabinoid re‐uptake process, which also has affinity for the vanilloid VR1 receptors, is able to reduce hyperkinesia, and causes recovery from neurochemical deficits, in a rat model of Huntington's disease (HD) generated by bilateral intrastriatal injections of 3‐nitropropionic acid (3NP). In the present study, we wanted to explore the mechanism(s) by which AM404 produces its antihyperkinetic effect in 3NP‐lesioned rats by employing several experimental approaches. First, we tried to block the effects of AM404 with selective antagonists for the CB1 or VR1 receptors, i.e. SR141716A and capsazepine, respectively. We found that the reduction caused by AM404 of the increased ambulation exhibited by 3NP‐lesioned rats in the open‐field test was reversed when the animals had been pre‐treated with capsazepine but not with SR141716A, thus suggesting a major role of VR1 receptors in the antihyperkinetic effects of AM404. However, despite the lack of behavioral effects of the CB1 receptor antagonist, the pretreatment with this compound abolished the recovery of neurochemical [γ‐aminobutyric acid (GABA) and dopamine] deficits in the caudate‐ putamen caused by AM404, as also did capsazepine. In a second group of studies, we wanted to explore the potential antihyperkinetic effects of various compounds which, compared to AM404, exhibit more selectivity for either the endovanilloid or the endocannabinoid systems. First, we tested VDM11 or AM374, two selective inhibitors or the endocannabinoid re‐uptake or hydrolysis, respectively. Both compounds were mostly unable to reduce hyperkinesia in 3NP‐lesioned rats, although VDM11 produced a certain motor depression, and AM374 exhibited a trend to stimulate ambulation, in control rats. We also tested the effects of selective direct agonists for VR1 (capsaicin) or CB1 (CP55,940) receptors. Capsaicin exhibited a strong antihyperkinetic activity and, moreover, was able to attenuate the reductions in dopamine and GABA transmission provoked by the 3NP lesion, whereas CP55,940 had also antihyperkinetic activity but was unable to cause recovery of either dopamine or GABA deficits in the basal ganglia. In summary, our data indicate a major role for VR1 receptors, as compared to CB1 receptors, in the antihyperkinetic effects and the recovery of neurochemical deficits caused in 3NP‐lesioned rats by compounds that activate both CB1 and VR1 receptors, either directly or via manipulation of the levels of endogenous agonists.
Promotion of tau phosphorylation by MAP kinase Erk1/2 is accompanied by reduced cholesterol level in detergent‐insoluble membrane fraction in Niemann–Pick C1‐deficient cells
Authors: Sawamura Naoya , Gong Jian‐Sheng , Chang Ta‐Yuan , Yanagisawa Katsuhiko , Michikawa Makoto
Published: March 2003

Niemann–Pick type C (NPC) disease is a cholesterol‐storage disease accompanied by neurodegeneration with the formation of neurofibrillary tangles, the major component of which is the hyperphosphorylated tau. Here, we examined the mechanism underlying hyperphosphorylation of tau using mutant Chinese hamster ovary (CHO) cell line defective in NPC1 (CT43) as a tool. Immunoblot analysis revealed that tau was hyperphosphorylated at multiple sites in CT43 cells, but not in their parental cells (25RA) or the wild‐type CHO cells. In CT43 cells, mitogen‐activated protein (MAP) kinase Erk1/2 was activated and the specific MAPK inhibitor, PD98059, attenuated the hyperphosphorylation of tau. The amount of protein phosphatase 2A not bound to microtubules was decreased in CT43 cells. CT43 cells but not 25RA cells were amphotericin B‐resistant, indicating that cholesterol level in the plasma membrane of CT43 is decreased. In addition, the level of cholesterol in the detergent‐insoluble, low‐density membrane (LDM) fraction of CT43 cells was markedly reduced compared with the other two types of CHO cells. As LDM domain plays critical role in signaling pathways, these results suggest that the reduced cholesterol level in LDM domain due to the lack of NPC1 may activate MAPK, which subsequently promotes tau phosphorylation in NPC1‐deficient cells.
Role of NAD(P)H:quinone oxidoreductase in the progression of neuronal cell death in vitro and following cerebral ischaemia in vivo
Authors: Kapinya Krisztian J. , Harms Ulrike , Harms Christoph , Blei Katharina , Katchanov Juri , Dirnagl Ulrich , Hörtnagl Heide
Published: March 2003

A direct involvement of the antioxidant enzyme NAD(P)H:quinone oxidoreductase (NQO1) in neuroprotection has not yet been shown. The aim of this study was to examine changes, localization and role of NQO1 after different neuronal injury paradigms. In primary cultures of rat cortex the activity of NQO1 was measured after treatment with ethylcholine aziridinium (AF64A; 40 µm), inducing mainly apoptotic cell death, or oxygen‐glucose deprivation (OGD; 120 min), which combines features of apoptotic and necrotic cell death. After treatment with AF64A a significant NQO1 activation started after 24 h. Sixty minutes after OGD a significant early induction of the enzyme was observed, followed by a second increase 24 h later. Enzyme activity was preferentially localized in glial cells in control and injured cultures, however, expression also occurred in injured neuronal cells. Inhibition of the NQO1 activity by dicoumarol, cibacron blue or chrysin (1–100 nm) protected the cells both after exposure to AF64A or OGD as assessed by the decreased release of lactate dehydrogenase. Comparable results were obtained in vivo using a mouse model of focal cerebral ischaemia. Dicoumarol treatment (30 nmol intracerebroventricular) reduced the infarct volume by 29% (p = 0.005) 48 h after the insult. After chemical induction of NQO1 activity by t‐butylhydroquinone in vitro neuronal damage was exaggerated. Our data suggest that the activity of NQO1 is a deteriorating rather than a protective factor in neuronal cell death.
Oxidative stress‐mediated down‐regulation of bcl‐2 promoter in hippocampal neurons
Authors: Pugazhenthi Subbiah , Nesterova Albina , Jambal Purevsuren , Audesirk Gerald , Kern Marcey , Cabell Leigh , Eves Eva , Rosner Marsha R. , Boxer Linda M. , Reusch Jane E.‐B.
Published: March 2003

Generation of oxidative stress/reactive oxygen species (ROS) is one of the causes of neuronal apoptosis. We have examined the effects of ROS at the transcriptional level in an immortalized hippocampal neuronal cell line (H19‐7) and in rat primary hippocampal neurons. Treatment of H19‐7 cells with hydrogen peroxide (150 µm) resulted in a 40% decrease in Bcl‐2 protein and a parallel decrease in bcl‐2 mRNA levels. H19‐7 cells overexpressing bcl‐2 were found to be resistant to ROS‐induced apoptosis. We had previously shown that bcl‐2 promoter activity is positively regulated by the transcription factor cyclic AMP response element binding protein (CREB) in neurons. In the present study, we demonstrate that ROS decreases the activity of luciferase reporter gene driven by a cyclic AMP response element site containing bcl‐2 promoter. Exposure of neurons to ROS for 6 h resulted in basal and fibroblast growth factor‐2‐stimulated phosphorylation/activation of CREB. Chronic 24 h treatment with ROS led to a significant (p < 0.01) decrease in CREB protein and CREB mRNA levels. Adenoviral overexpression of wild type CREB in H19‐7 cells resulted in significant (p < 0.01) protection against ROS‐induced apoptosis through up‐regulation of Bcl‐2 expression whereas dominant negative CREB exaggerated the injury. These findings demonstrate that loss of CREB function contributes to oxidative stress‐induced neuronal dysfunction.
Gender bias in nursing care? Gender‐related differences in patient satisfaction with the quality of nursing care
Authors: Foss Christina
Published: March 2003

Gender bias in nursing care? Gender‐related differences in patient satisfaction with the quality of nursing care

Gender‐related differences in experience with nursing care, was studied using data from a Norwegian survey of patient‐satisfaction. The survey included 1469 male and 1226 female patients. Results showed that young female patients were less content with all aspects of nursing care when compared with young male patients. Female patients experienced, quite contrary to their male counterparts, that the nursing staff was less committed and caring, has less time and was less skilled. The young women were also less content with what they felt was a lack of opportunity to provide the staff with information they believed to be important to their condition or ailment. Analysis also revealed that female patients, compared with their male counterparts, indicated a higher score on the subjective importance of the different aspects of care. These findings are discussed on the basis of gender‐related research in general. The finding of lower satisfaction amongst younger female patients could be ascribed to the power‐balance between nursing staff and patients. The discussion shows, however, that there are a number of possible interpretations as to why female patients are less content with nursing care compared with male patients. As the reasons for the findings may be derived from several sources it becomes evident that there is a need for further research using alternative approaches.
Life situation and function in elderly people with and without leg ulcers
Authors: Wissing U. , Ek A.‐C. , Unosson M.
Published: March 2003

Life situation and function in elderly people with and without leg ulcers

The majority of elderly patients with leg ulcers live at home and receive treatment for their ulcers within the primary health care system. Little is known about the patients' ability or behaviour in the life situation and how well they manage their daily life at home. The Philadelphia Geriatric Center Multilevel Assessment Instrument (PGC MAI) was used to assess and compare the life situation in 70 patients (mean age 79 ± 6.5 years) with leg ulcers and in 74 elderly persons (mean age 80 ± 5.7 years) without leg ulcers. The patients with leg ulcers had significantly lower mean values in the domains of physical health, activity of daily living (ADL), cognition, time use and social behaviour, personal adjustment and environmental quality than those without ulcers. Sixty‐three percent of the patients reported ulcer‐related pain, and all of them were dependent on health care personnel for dressing changes. This may indicate that the life situation among elderly persons with leg ulcers is not so good as compared with that of elderly persons without ulcers and that patients with leg ulcers are more vulnerable than elderly people of the same age.
Patients' conceptions of coronary heart disease – a phenomenographic analysis
Authors: Kärner Anita , Göransson Anne , Bergdahl Björn
Published: March 2003

Readjustment after an event of coronary heart disease (CHD) is defined to comprise cognitive, instrumental and affective components. The cognitive dimension refers to understanding of the disease. Twenty‐three patients (<60 years) with CHD were interviewed about the nature of their disease and encouraged to use their own words. The study was conducted 1 year after the event of myocardial infarction (MI) and some patients had also been revascularized. The interviews were transcribed in extenso and analysed according to the phenomenographic approach. The main finding was the great variation of conceptions revealed. Six different conceptions were found concerning CHD. Some patients comprehended MI by involving (A) blood and vessels, (B) either blood or vessel or referred to (C) risk factors/symptoms. Angina pectoris was expressed as (A) insufficient heart capacity, (B) atherosclerosis/contracted vessel or as (C) symptoms. Several patients found it difficult to expand their answers and some expressed misconceptions about the course of events. Patients' pre‐existing knowledge and their way of reasoning about central phenomena related to their disease should be taken into consideration in patient education and is also applicable in individual encounters with patients.
Breast cancer patients' experiences of lymphoedema
Authors: Johansson K. , Holmström H. , Nilsson I. , Ingvar C. , Albertsson M. , Ekdahl C.
Published: March 2003

The aim of this study was to explore employed women's experiences of light or moderate arm lymphoedema following breast cancer treatment in order to gain a deeper understanding of this phenomenon. Twelve women took part in a semistructured interview. A qualitative method with a phenomenological approach was applied to analyse data. In order to integrate the experiences in the everyday life of the women, a critical incident method was used. The findings indicate that there are many different practical and psychosocial problems related to arm lymphoedema. Three main themes were common to all the women. These themes were: (i) Attitudes from people in their surroundings, including reactions to the problem from other people and reactions from the women on the attitudes of other people. (ii) Discovery and understanding of oedema as a chronic disease and its treatment. (iii) Coping, including both problem‐focused and emotion‐focused strategies. The problems integrated in daily life were of low frequency but of considerable importance to the women. In conclusion, it is of great importance that health care professionals should be aware of and have knowledge about these problems. The women's needs for expressing their experiences of arm lymphoedema may be encouraged at the time of discovery and then regularly as long as the women seek care. Efforts may be made to strengthen the women's coping skills, eventually in a multidisciplinary approach. The interaction skills of health care professionals are probably of great importance in strengthening the resources of the women leading to a positive outcome.
Health promotion in the workplace: the perspective of unskilled workers in a hospital setting
Authors: Gunnarsdóttir S. , Björnsdóttir K.
Published: March 2003

It is important to explore the potential for health promotion from the perspective of participants in a particular situation. This study focuses on experiences of well‐being and the potential for health promotion among unskilled workers in the kitchen and laundry room in an acute care hospital in Iceland. These experiences are analysed in light of the material and structural factors that shape working conditions. The research method used was grounded theory. The data were formal and informal interviews, and participant observation. The findings revealed considerable differences between the two work groups. At both sites strain on the body, caused by excessive noise, heavy lifting and uncomfortable working arrangements, were identified. Similarly, the work was often experienced as monotonous and demanding. Human relations were identified as a key factor in ameliorating the conditions that led to experiences of strain by the workers at both work sites. This was however where the two work places differed. In the laundry room, the workers felt respected and acknowledged by their coworkers and managers. Belonging to the work group was important and they felt listened to by the supervisor. Very little cohesiveness was observed among the workers in the kitchen. The managers seemed to be absent from the floor, workers were divided into work groups that sometimes showed antagonism towards each other and few channels were available for complaints and suggestions for improvement. The workers in the laundry room, on the other hand, related positive experiences of work. They felt that steps were taken by managers to improve working conditions to the extent possible and participated in those attempts by bringing up suggestions, implementing change and developing their own ways of coping with the work. This study gives important directions for health promotion in the workplace, emphasizing human relations at work, rather than individual health behaviour away from the work setting.
Microsatellites from genes show polymorphism in two related Oreochromis species
Authors: Yue G. H. , Orban L.
Published: March 2003

Six microsatellites were detected in the IGF‐II, GH2, prolactin I and insulin genes of Mozambique tilapia (Oreochromis mossambicus) and Nile tilapia (Oreochromis niloticus) by screening DNA sequences deposited to GenBank. Genotyping of 24 individuals from each species revealed that all six microsatellites were polymorphic in both species. In Mozambique tilapia the number of alleles ranged from 3 to 17 (average 9.8), whereas in Nile tilapia the range was 4–21 (average 10.5). The range of expected heterozygosity values were 0.44–0.95 (average 0.79) in Mozambique tilapia, and 0.52–0.96 (average 0.73) in Nile tilapia.
Microsatellite loci in the Lahontan tui chub, Gila bicolor obesa, and their utilization in other chub species
Authors: Meredith Erin P. , May Bernie
Published: March 2003

Primers were developed for 17 microsatellite loci from an enriched (GATA)n library from DNA from Gila bicolor obesa. These primers were tested for cross‐species amplification in Gila bicolor snyderi, Gila orcutti and Gila coerulea.
Isolation and characterization of six polymorphic microsatellite loci in South African hares (Lepus saxatilis F. Cuvier, 1823 and Lepus capensis Linnaeus, 1758)
Authors: Kryger U. , Robinson T. J. , Bloomer P.
Published: March 2003

We have developed six novel, polymorphic microsatellite markers for the scrub hare, Lepus saxatilis. These markers have been tested for 150 scrub hares and 67 Cape hares from different localities across southern Africa. All six loci amplified consistently well and most were highly polymorphic. Four loci amplified consistently in five different leporid genera. The microsatellites presented here will be useful for phylogeographical studies in the scrub hare and other leporidae.
Dinucleotide repeat microsatellite markers for buck’s‐horn plantain (Plantago coronopus)
Authors: Koorevaar G. N. , Ivanovic S. , Van Damme J. M. M. , Koelewijn H. P. , Van’T Westende W. P. C. , Smulders M. J. M. , Vosman B.
Published: March 2003

Eleven polymorphic microsatellite loci were obtained from a GA enriched genomic library, constructed from DNA of buck’s‐horn plantain (Plantago coronopus). The microsatellite loci were tested on 24 genotypes. These plants were collected from meadows along the coast, located on 11 sites ranging from the southwest to the northeast of the Netherlands. In this set of plants the isolated microsatellites were highly polymorphic with 3–24 alleles per locus and a maximum observed heterozygosity of 0.91. Some of the microsatellite loci also showed amplification in two other plantain species (P. lanceolata and P. maritima).
Polymorphic microsatellites from silver crucian carp (Carassius auratus gibelio Bloch) and cross‐amplification in common carp (Cyprinus carpio L.)
Authors: Yue G. H. , Orban L.
Published: March 2003

Fifteen polymorphic microsatellites were isolated from the genome of silver crucian carp (Carassius auratus gibelio Bloch). Allele numbers ranged from two to four with an average of 2.7/locus, and the proportion of tri‐ and diallelic heterozygotes was 99.3%. The individuals tested seem to have originated from two different clonal lines: 14 of 16 showed the same genotype at all loci tested, whereas the remaining two were also identical, but different from the former ones. Eleven out of 15 primer pairs cross‐amplified products from the genome of common carp, whereas only five from that of zebrafish.
Isolation and characterization of polymorphic microsatellite markers in Eurasian vulture Gyps fulvus
Authors: Mira S. , Billot C. , Guillemaud T. , Palma L. , Cancela M. L.
Published: March 2003

To obtain polymorphic molecular markers for population genetic and conservation studies in the Eurasian vulture Gyps fulvus populations, we screened a size‐selected partial genomic library enriched for microsatellites with dinucleotide motifs. A total of five polymorphic markers were obtained. The number of alleles ranged from two to nine and the observed and expected heterozygosity were very similar. These markers will be very useful for studying population structure and to evaluate conservation programmes.
Isolation of twelve microsatellite loci, using an enrichment protocol, in the phytopathogenic fungus Puccinia striiformis f.sp. tritici
Authors: Enjalbert J. , Duan X. , Giraud T. , Vautrin D. , De Vallavieille‐Pope C. , Solignac M.
Published: March 2003

We report the characterization of 12 microsatellite markers in the biotrophic fungus Puccinia striiformis f.sp. tritici, responsible for yellow rust on wheat. An enrichment protocol was used to isolate microsatellite loci, and polymorphism was explored with 96 isolates from natural populations collected from several French and Chinese locations. Eight primers (67%) showed cross‐amplification when tested with eight isolates of P. triticina.