bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of brain mitochondrial respiration by dopamine: involvement of H2O2 and hydroxyl radicals but not glutathione–protein–mixed disulfides
Authors: Gluck Martin , Ehrhart Julie , Jayatilleke Elizabeth , Zeevalk Gail D.
Published: March 2003

Examination of the downstream mediators responsible for inhibition of mitochondrial respiration by dopamine (DA) was investigated. Consistent with findings reported by others, exposure of rat brain mitochondria to 0.5 mm DA for 15 min at 30°C inhibited pyruvate/glutamate/malate‐supported state‐3 respiration by 20%. Inhibition was prevented in the presence of pargyline and clorgyline demonstrating that mitochondrial inhibition arose from products formed following MAO metabolism and could include hydrogen peroxide (H2O2), hydroxyl radical, oxidized glutathione (GSSG) or glutathione–protein mixed disulfides (PrSSG). As with DA, direct incubation of intact mitochondria with H2O2 (100 µm) significantly inhibited state‐3 respiration. In contrast, incubation with GSSG (1 mm) had no effect on O2 consumption. Exposure of mitochondria to 1 mm GSSG resulted in a 3.3‐fold increase in PrSSG formation compared with 1.4‐ and 1.5‐fold increases in the presence of 100 µm H2O2 or 0.5 mm DA, respectively, suggesting a dissociation between PrSSG formation and effects on respiration. The lack of inhibition of respiration by GSSG could not be accounted for by inadequate delivery of GSSG into mitochondria as increases in PrSSG levels in both membrane‐bound (2‐fold) and intramatrix (3.5‐fold) protein compartments were observed. Furthermore, GSSG was without effect on electron transport chain activities in freeze–thawed brain mitochondria or in pig heart electron transport particles (ETP). In contrast, H2O2 showed differential effects on inhibition of respiration supported by different substrates with a sensitivity of succinate > pyruvate/malate > glutamate/malate. NADH oxidase and succinate oxidase activities in freeze–thawed mitochondria were inhibited with IC50 approximately 2–3‐fold higher than in intact mitochondria. ETPs, however, were relatively insensitive to H2O2. Co‐administration of desferrioxamine with H2O2 had no effect on complex I‐associated inhibition in intact mitochondria, but attenuated inhibition of rotenone‐sensitive NADH oxidase activity by 70% in freeze–thawed mitochondria. The results show that DA‐associated inhibition of respiration is dependent on MAO and that H2O2 and its downstream hydroxyl radical rather than increased GSSG and subsequent PrSSG formation mediate the effects.
Activation of nuclear Ca2+/calmodulin‐dependent protein kinase II and brain‐derived neurotrophic factor gene expression by stimulation of dopamine D2 receptor in transfected NG108‐15 cells
Authors: Takeuchi Yusuke , Fukunaga Kohji , Miyamoto Eishichi
Published: March 2003

We identified the isoforms of Ca2+/calmodulin‐dependent protein kinase II (CaM kinase II) subunits in rat striatum. All four subunits of CaM kinase II α, β, γ and δ were detected including the isoforms of αB, γA, γA′, γA.B, δ3 and δ7 with nuclear localization signal. We established NG108‐15 cells with the stably expressed dopamine D2L receptor (D2LR, long form), which is an alternative splicing variant. The cells were termed NGD2L. Immunostaining demonstrated that D2LR was localized in plasma membranes. Calcium imaging with fluo‐3 AM revealed that quinpirole, a D2R agonist, increased the intracellular Ca2+, which was blocked by treatment with sulpiride and pertussis toxin in NGD2L cells, but not in mock cells. Furthermore, stimulation of D2LR with quinpirole in NGD2L cells activated the nuclear isoform of CaM kinase II. Stimulation of D2LR increased the expression of exon III‐ and IV‐BDNF mRNA. Overexpression of CaM kinase II δ3 increased exon IV‐ but not exon III‐BDNF mRNA. These results suggest that D2R is involved in the activation of the nuclear isoform of CaM kinase II and thereby in stimulation of gene expression through Ca2+ signaling.
Peroxynitrite affects exocytosis and SNARE complex formation and induces tyrosine nitration of synaptic proteins
Authors: Di Stasi A. M. Michela , Mallozzi Cinzia , Macchia Gianfranco , Maura Guido , Petrucci Tamara C. , Minetti Maurizio
Published: March 2003

The reactive species peroxynitrite, formed via the near diffusion‐limited reaction of nitric oxide and superoxide anion, is a potent oxidant that contributes to tissue damage in neurodegenerative disorders. Peroxynitrite readily nitrates tyrosine residues in proteins, producing a permanent modification that can be immunologically detected. We have previously demonstrated that in the nerve terminal, nitrotyrosine immunoreactivity is primarily associated with synaptophysin. Here we identify two other presynaptic proteins nitrated by peroxynitrite, Munc‐18 and SNAP25, both of which are involved in sequential steps leading to vesicle exocytosis. To investigate whether peroxynitrite affects vesicle exocytosis, we used the fluorescent dye FM1‐43 to label a recycling population of secretory vesicles within the synaptosomes. Bolus addition of peroxynitrite stimulated exocytosis and glutamate release. Notably, these effects were strongly reduced in the presence of NaHCO3, indicating that peroxynitrite acts mainly intracellularly. Furthermore, peroxynitrite enhanced the formation of the sodium dodecyl sulfate‐resistant SNARE complex in a dose‐dependent manner (100–1000 µm) and induced the formation of 3‐nitrotyrosine in proteins of SNARE complex. These data suggest that modification(s) of synaptic vesicle proteins induced by peroxynitrite may affect protein–protein interactions in the docking/fusion steps, thus promoting exocytosis, and that, under excessive production of superoxide and nitric oxide, neurons may up‐regulate neuronal signaling.
The internal pH of synaptic‐like microvesicles in rat pinealocytes in culture
Authors: Hayashi Mitsuko , Yamamoto Akitsugu , Moriyama Yoshinori
Published: March 2003

Synaptic‐like microvesicles (SLMVs) are morphological and functional equivalents of neuronal synaptic vesicles, and are responsible for the storage and secretion of classical neurotransmitters in various endocrine cells. Vacuolar H+‐ATPase acidifies the internal space of these organelles and provides a driving force for the uptake of neurotransmitters. Thus, the luminal pH is an important determinant of the function of SLMVs, although its value in living cells is unknown. Here, we determined the luminal pH of SLMVs in living rat pinealocytes by means of an immunoelectronmicroscopic procedure basedon the distribution of an amphipathic amine, 3‐(2,4‐dinitroanilino)‐3′‐amino‐N‐methyldipropylamine (DAMP). Use of double‐labeling techniques with antibodies against 2,4‐dinitrophenol for DAMP and synaptophysin for SLMVs, and of frozen ultrathin sections enabled us to determine the number of immunogold particles for DAMP per µm2 of SLMVs. Using the density of gold particles, the luminal pH of SLMVs was calculated to be 5.11 ± 0.01. Treatment with either 1 µm bafilomycin A1, a specific inhibitor of vacuolar H+‐ATPase , or 50 mm ammonium chloride, a dissipater of the transmembrane pH gradient, increased the luminal pH to 6.04 ± 0.07 and 6.05 ± 0.11, respectively. Simultaneously, the lysosomal pH was found to be 5.14 ± 0.07, which increased to 5.77 ± 0.09 and 5.93 ± 0.13 with bafilomycin A1 and ammonium chloride, respectively. It is concluded that the luminal pH of SLMVs is comparable to that of lysosomes in vivo.
Trafficking of the vesicular acetylcholine transporter in SN56 cells: a dynamin‐sensitive step and interaction with the AP‐2 adaptor complex
Authors: Barbosa José , Ferreira Lucimar T. , Martins‐Silva C. , Santos Magda S. , Torres Gonzalo E. , Caron Marc G. , Gomez Marcus V. , Ferguson Stephen S. G. , Prado Marco A. M. , Prado Vania F.
Published: March 2003

The pathways by which synaptic vesicle proteins reach their destination are not completely defined. Here we investigated the traffic of a green fluorescent protein (GFP)‐tagged version of the vesicular acetylcholine transporter (VAChT) in cholinergic SN56 cells, a model system for neuronal processing of this cargo. GFP‐VAChT accumulates in small vesicular compartments in varicosities, but perturbation of endocytosis with a dominant negative mutant of dynamin I‐K44A impaired GFP‐VAChT trafficking to these processes. The protein in this condition accumulated in the cell body plasma membrane and in large vesicular patches therein. A VAChT endocytic mutant (L485A/L486A) was also located at the plasma membrane, however, the protein was not sorted to dynamin I‐K44A generated vesicles. A fusion protein containing the VAChT C‐terminal tail precipitated the AP‐2 adaptor protein complex from rat brain, suggesting that VAChT directly interacts with the endocytic complex. In addition, yeast two hybrid experiments indicated that the C‐terminal tail of VAChT interacts with the µ subunit of AP‐2 in a di‐leucine (L485A/L486A) dependent fashion. These observations suggest that the di‐leucine motif regulates sorting of VAChT from the soma plasma membrane through a clathrin dependent mechanism prior to the targeting of the transporter to varicosities.
Gene transfer of the Caenorhabditis elegans n‐3 fatty acid desaturase inhibits neuronal apoptosis
Authors: Ge Yinlin , Wang Xiaoying , Chen Zhihong , Landman Natalie , Lo Eng H. , Kang Jing X.
Published: March 2003

Previous studies have shown that n‐3 polyunsaturated fatty acids (PUFAs) can exert an antiapoptotic effect on neurons. The present study was designed to investigate whether the Caenorhabditis elegans fat‐1 gene encoding an n‐3 fatty acid desaturase (an enzyme that converts n‐6 PUFAs to corresponding n‐3 PUFAs) can be expressed functionally in rat cortical neurons and whether its expression can change the ratio of n‐6 : n‐3 fatty acids in the cell membrane and exert an effect on neuronal apoptosis. Infection of primary rat cortical cultures with Ad‐fat‐1 resulted in high expression of the fat‐1 gene. Lipid analysis indicated a decrease in the ratio of n‐6 : n‐3 PUFAs from 5.9 : 1 in control cells, to 1.45 : 1 in cells expressing the n‐3 fatty acid desaturase. Accordingly, the levels of prostaglandin E2, an eicosanoid derived from n‐6 PUFA, were significantly lower in cells infected with Ad‐fat‐1 when compared with control cells. Finally, there was a significant inhibition of growth factor withdrawal‐induced apoptotic cell death in neurons expressing the fat‐1 gene. These results demonstrate that expression of the fat‐1 gene can inhibit apoptotic cell death in neurons and suggest that the change in the n‐6 : n‐3 fatty acid ratio may play a key role in this protective effect.
Inhibition of tryptophan hydroxylase activity and decreased 5‐HT1A receptor binding in a mouse model of Huntington's disease
Authors: Yohrling IV George J. , Jiang George C.‐T. , DeJohn Molly M. , Robertson Daniel J. , Vrana Kent E. , Cha Jang‐Ho J.
Published: March 2003

The pathogenic mechanisms of the mutant huntingtin protein that cause Huntington's disease (HD) are unknown. Previous studies have reported significant decreases in the levels of serotonin (5‐HT) and its metabolite 5‐hydroxyindoleacetic acid (5‐HIAA) in the brains of the R6/2 transgenic mouse model of HD. In an attempt to elucidate the cause of these neurochemical perturbations in HD, the protein levels and enzymatic activity of tryptophan hydroxylase (TPH), the rate‐limiting enzyme in 5‐HT biosynthesis, were determined. Enzyme activity was measured in brainstem homogenates from 4‐, 8‐, and 12‐week‐old R6/2 mice and compared with aged‐matched wild‐type control mice. We observed a 62% decrease in brainstem TPH activity (p = 0.009) in 4‐week‐old R6/2 mice, well before the onset of behavioral symptoms. In addition, significant decreases in TPH activity were also observed at 8 and 12 weeks of age (61%, p = 0.02 and 86%, p = 0.005, respectively). In the 12‐week‐old‐mice, no change in immunoreactive TPH was observed. In vitro binding showed that TPH does not bind to exon 1 of huntingtin in a polyglutamine‐dependent manner. Specifically, glutathione‐S‐transferase huntingtin exon 1 proteins with 20, 32 or 53 polyglutamines did not interact with radiolabeled tryptophan hydroxylase. Therefore, the inhibition of TPH activity does not appear to result from a direct huntingtin/TPH interaction. Receptor binding analyses for the 5‐HT1A receptor in 12‐week‐old R6/2 mice revealed significant reductions in 8‐OH‐[3H]DPAT binding in several hippocampal and cortical regions. These results demonstrate that the serotonergic system in the R6/2 mice is severely disrupted in both presymptomatic and symptomatic mice. The presymptomatic inhibition of TPH activity in the R6/2 mice may help explain the functional consequences of HD and provide insights into new targets for pharmacotherapy.
Differential regulation of metabotropic glutamate receptor 5‐mediated phosphoinositide hydrolysis and extracellular signal‐regulated kinase responses by protein kinase C in cultured astrocytes
Authors: Peavy Richard D. , Sorensen Scott D. , Conn P. Jeffrey
Published: March 2003

The metabotropic glutamate receptor 5 (mGluR5) exhibits a rapid loss of receptor responsiveness to prolonged or repeated agonist exposure. This receptor desensitization has been seen in a variety of native and recombinant systems, and is thought to result from receptor‐mediated, protein kinase C (PKC)‐dependent phosphorylation of the receptor, uncoupling it from the G protein in a negative feedback regulation. We have investigated the rapid PKC‐mediated desensitization of mGluR5 in cortical cultured astrocytes by measuring downstream signals from activation of mGluR5. These include activation of phosphoinositide (PI) hydrolysis, intracellular calcium transients, and extracellular signal‐regulated kinase 2 (ERK2) phosphorylation. We present evidence that PKC plays an important role in rapid desensitization of PI hydrolysis and calcium signaling, but not in ERK2 phosphorylation. This differential regulation of mGluR5‐mediated responses suggests divergent signaling and regulatory pathways which may be important mechanisms for dynamic integration of signal cascades.
A site‐specific mutation of tyrosine hydroxylase reduces feedback inhibition by dopamine in genetically modified cells grafted in parkinsonian rats
Authors: Chang J. W. , Lee W. Y. , Milstien S. , Kang U. J.
Published: March 2003

Aromatic l‐amino acid decarboxylase (AADC) is necessary for conversion of l‐DOPA to dopamine. Therefore, AADC gene therapy has been proposed to enhance pharmacological or gene therapies delivering l‐DOPA. However, addition of AADC to the grafts of genetically modified cells expressing tyrosine hydroxylase (TH) and GTP cyclohydrolase 1 (GCH1), which produce l‐DOPA in parkinsonian rats, resulted in decreased production of l‐DOPA and dopamine owing to feedback inhibition of TH by dopamine. End‐product feedback inhibition has been shown to be mediated by the regulatory domain of TH, and site‐specific mutation of serine 40 makes TH less susceptible to dopamine inhibition. Therefore, we investigated the efficacy of using TH with serine 40 mutated to leucine (mTH) in an ex vivo gene‐therapy paradigm. Primary fibroblasts (PF) from Fischer 344 rats were transduced with retrovirus to express mTH or wild‐type rat TH cDNA (wtTH). Both cell types were also transduced with GCH1 to provide the obligate TH cofactor, tetrahydrobiopterin. PF transfected with AADC were used as coculture and cografting partners. TH activities and l‐DOPA production in culture were comparable between PFwtTHGC and PFmTHGC cells. In cocultures with PFAADC cells, PFmTHGC cells showed significant reduction in the inhibitory effect of dopamine compared with PFwtTHGC cells. In vivo microdialysis measurement showed that cografting PFAADC cells with PFmTHGC cells resulted in smaller decreases in l‐DOPA and no reduction in dopamine levels compared with cografts of PFAADC cells with PFwtTHGC cells, which decreased both l‐DOPA and dopamine levels. Maintenance of dopamine levels with lower levels of l‐DOPA would result in more focused local delivery of dopamine and less potential side‐effects arising from l‐DOPA diffusion into other structures. These data support the hypothesis that mutation of serine 40 attenuates TH end‐product inhibition in vivo and illustrates the importance of careful consideration of biochemical pathways and interactions between multiple genes in gene therapy.
Changes in activity and expression of phosphofructokinase in different rat brain regions after basal forebrain cholinergic lesion
Authors: Zeitschel Ulrike , Schliebs Reinhard , Roßner Steffen , Bigl Volker , Eschrich Klaus , Bigl Marina
Published: March 2003

Selective lesion of rat basal forebrain by the cholinergic immunotoxin 192IgG‐saporin was used as an animal model to address the question of whether the changes in cortical glucose metabolism observed in patients with Alzheimer's disease may be related to impaired cholinergic transmission. At different times after creating the immunolesion, the isoenzyme pattern and steady‐state mRNA levels of the key glycolytic enzyme phosphofructokinase were determined in cortex, hippocampus, basal forebrain and nucleus caudatus. The loss of cholinergic input was accompanied by a persistent decrease in choline acetytransferase and acetylcholine esterase activities in the cortical target areas similar to the cholinergic malfunction seen in Alzheimer's dementia. The basal forebrain lesion induced by the immunotoxin resulted in a transient increase in phosphofructokinase activity peaking on day 7 after inducing the lesion in cortical areas. In parallel, an increased steady‐state level of phosphofructokinase mRNA was determined by RT/real‐time PCR and in situ hybridization. In contrast, analysis by western blotting and quantitative PCR revealed no changes in the phosphofructokinase isoenzyme pattern after immunolesion. It is concluded that common metabolic mechanisms may underlie the degenerative and repair processes in denervated rat brain and in the diseased Alzheimer's brain.
Proteomic analysis of CA1 and CA3 regions of rat hippocampus and differential susceptibility to intermittent hypoxia
Authors: Gozal Evelyne , Gozal David , Pierce William M. , Thongboonkerd Visith , Scherzer Janice A. , R. Sachleben Leroy , Brittian Kenneth R. , Guo Shang‐Z. , Cai Jian , Klein Jon B.
Published: March 2003

The CA1 and CA3 regions of the hippocampus markedly differ in their susceptibility to hypoxia in general, and more particularly to the intermittent hypoxia that characterizes sleep apnea. Proteomic approaches were used to identify proteins differentially expressed in the CA1 and CA3 regions of the rat hippocampus and to assess changes in protein expression following a 6‐h exposure to intermittent hypoxia (IH). Ninety‐nine proteins were identified, and 15 were differentially expressed in the CA1 and the CA3 regions. Following IH, 32 proteins in the CA1 region and only 7 proteins in the more resistant CA3 area were up‐regulated. Hypoxia‐regulated proteins in the CA1 region included structural proteins, proteins related to apoptosis, primarily chaperone proteins, and proteins involved in cellular metabolic pathways. We conclude that IH‐mediated CA1 injury results from complex interactions between pathways involving increased metabolism, induction of stress‐induced proteins and apoptosis, and, ultimately, disruption of structural proteins and cell integrity. These findings provide initial insights into mechanisms underlying differences in susceptibility to hypoxia in neural tissue, and may allow for future delineation of interventional strategies aiming to enhance neuronal adaptation to IH.
A novel in vivo post‐translational modification of p53 by PARP‐1 in MPTP‐induced parkinsonism
Authors: Mandir Allen S. , Simbulan‐Rosenthal Cynthia M. , Poitras Marc F. , Lumpkin John R. , Dawson Valina L. , Smulson Mark E. , Dawson Ted M.
Published: March 2003

Sporadic Parkinson's disease (PD) affects primarily dopaminergic neurons of the substantia nigra pars compacta. There is evidence of necrotic and apoptotic neuronal death in PD, but the mechanisms behind selected dopaminergic neuronal death remain unknown. The tumor suppressor protein p53 functions to selectively destroy stressed or abnormal cells during life and development by means of necrosis and apoptosis. Activation of p53 leads to death in a variety of cells including neurons. p53 is a target of the nuclear enzyme Poly(ADP‐ribose)polymerase (PARP), and PARP is activated following DNA damage that occurs following 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP)‐induced neurotoxicity. MPTP is the favored in vivo model of PD, and reproduces the pathophysiology, anatomy and biochemistry of PD. p53 protein normally exhibits a fleeting half‐life, and regulation of p53 stability and activation is achieved mainly by post‐translational modification. We find that p53 is heavily poly(ADP‐ribosyl)ated by PARP‐1 following MPTP intoxication. This post‐translational modification serves to stabilize p53 and alters its transactivation of downstream genes. These influences of PARP‐1 on p53 may underlie the mechanisms of MPTP‐induced parkinsonism and other models of neuronal death.
Corticosterone acutely prolonged N‐methyl‐d‐aspartate receptor‐mediated Ca2+ elevation in cultured rat hippocampal neurons
Authors: Takahashi Taiki , Kimoto Tetsuya , Tanabe Nobuaki , Hattori Taka‐aki , Yasumatsu Nobuaki , Kawato Suguru
Published: March 2003

This work reports the first demonstration that corticosterone (CORT) has a rapid and transient effect on NMDA receptor‐mediated Ca2+ signaling in cultured rat hippocampal neurons. Using single cell Ca2+ imaging, CORT and agonists of glucocorticoid receptors were observed to modulate the NMDA receptor‐mediated Ca2+ signals in a completely different fashion from pregnenolone sulfate. In the absence of steroids, 100 µm NMDA induced a transient Ca2+ signal that lasted for 30–70 s in 86.1% of the neurons prepared from postnatal rats (3–5 days old). After pre‐treatment with 0.1–100 µm CORT for 10–20 min, NMDA induced extremely prolonged Ca2+ elevation. This prolonged Ca2+ elevation was terminated by the application of MK‐801 and followed by washing out of CORT. The proportion of CORT‐modulated neurons within the NMDA‐responsive cells increased from 25.1 to 95.5% when the concentration of CORT was raised from 0.1 to 50 µm. Substitution of BSA‐conjugated CORT produced essentially the same results. When hippocampal neurons were preincubated with 10 µm cortisol and 1 µm dexamethasone for 20 min, a very prolonged Ca2+ elevation was also observed upon NMDA stimulation. The CORT‐prolonged Ca2+ elevation caused a long‐lasting depolarization of the mitochondrial membrane, as observed with rhodamine 123. In contrast, incubation with 100 µm pregnenolone sulfate did not considerably alter the time duration of NMDA‐induced transient Ca2+ elevation, but caused a significant increase in the peak amplitude of Ca2+ elevation in hippocampal neurons. These results imply that high levels of CORT induce a rapid and non‐genomic prolongation of NMDA receptor‐mediated Ca2+ elevation, probably via putative membrane surface receptors for CORT in the hippocampal neurons.
Distinct effects of methamphetamine and cocaine on preprodynorphin messenger RNA in rat striatal patch and matrix
Authors: Adams David H. , Hanson Glen R. , Keefe Kristen A.
Published: March 2003

We and others previously reported that equimolar doses of methamphetamine and cocaine differentially increase preprodynorphin mRNA in striatum: methamphetamine causes a patchy increase, whereas cocaine produces a more homogenous one. The current study directly examined whether this effect reflects differential induction in the patch–matrix division of striatum, as identified by µ opioid receptor immunohistochemistry. In addition, we determined whether doses of cocaine (30 mg/kg) and methamphetamine (2 mg/kg) that produced equivalent increases in extracellular dopamine differentially affected preprodynorphin mRNA expression in striatum of male, Sprague–Dawley rats. In both experiments, methamphetamine and cocaine differentially affected preprodynorphin mRNA in striatum after 3 h. The high, equimolar dose of methamphetamine selectively increased preprodynorphin mRNA in the patch division of rostral striatum, whereas cocaine increased preprodynorphin mRNA throughout patch and matrix divisions of striatum. In contrast, a dose of methamphetamine (2.0 mg/kg) that caused an increase in extracellular dopamine similar to that produced by 30 mg/kg cocaine did not significantly affect preprodynorphin mRNA in any region of striatum. These data provide further evidence that cocaine and amphetamines exert distinct effects on the patch–matrix division of striatum and suggest further that the post‐synaptic consequences of elevated extracellular dopamine produced by methamphetamine and cocaine are distinct.
Inhibition of NADH oxidation by chloramphenicol in the freely moving rat measured by picosecond time‐resolved emission spectroscopy
Authors: Mottin Stéphane , Laporte Pierre , Cespuglio Raymond
Published: March 2003

Owing to the lack of methods capable to monitor the energetic processes taking place within small brain regions (i.e. nucleus raphe dorsalis, nRD), the neurotoxicity of various categories of substances, including antibiotics and psycho‐active drugs, still remains difficult to evaluate. Using an in vivo picosecond optical spectroscopy imaging method, we report that chloramphenicol (CAP), besides its well‐known ability to inhibit the mitochondria protein synthesis, also influences the NADH/NAD+ redox processes of the respiratory chain. At a 200‐mg/kg dose, CAP indeed produces a marked increase in the fluorescent signal of the nRD which, according to clear evidence, is likely to be related to the NADH concentration. This effect also implies an efficient inhibition of complex I of the respiratory chain by CAP. It refers to the mechanism through which the adverse effects of the antibiotic may take place. It could explain why paradoxical sleep, a state needing aerobic energy to occur, is suppressed after CAP administration. The present approach constitutes the first attempt to determine by fluorescence methods the effects of substances on deep brain structures of the freely moving animal. It points out that in vivo ultrafast optical methods are innovative and adequate tools for combined neurochemical and behavioural approaches.
MsGC‐II, a receptor guanylyl cyclase isolated from the CNS of Manduca sexta that is inhibited by calcium
Authors: Morton David B. , Nighorn Alan
Published: March 2003

We describe the cloning of a receptor guanylyl cyclase, MsGC‐II, from the CNS of the insect Manduca sexta. Sequence comparisons with other receptor guanylyl cyclases show that MsGC‐II is most similar to a predicted guanylyl cyclase in the Drosophila genome and to vertebrate retinal guanylyl cyclases. When expressed in COS‐7 cells, MsGC‐II exhibited a low level of basal activity that was nearly abolished in the presence of 10 µm calcium. Incubation with either a mammalian guanylyl cyclase‐activating protein or Drosophila frequenin resulted in only mild stimulation of activity, whereas incubation of COS‐7 cells expressing MsGC‐II with a variety of Manduca tissue extracts failed to stimulate enzyme activity above basal levels. Analysis of the tissue distribution of MsGC‐II revealed that it is nervous system specific. In the adult, MsGC‐II is present in neurons in the optic lobes, antennal lobes and cellular cortex, but it is most highly expressed in subsets of intrinsic mushroom body neurons. Thus, MsGC‐II appears to be a neural‐specific receptor guanylyl cyclase whose activity may be regulated either directly or indirectly by calcium.
Possible regulation by N‐methyl‐d‐aspartate receptors of proliferative progenitor cells expressed in adult mouse hippocampal dentate gyrus
Authors: Kitayama Tomoya , Yoneyama Masanori , Yoneda Yukio
Published: March 2003

An immunohistochemical technique was employed to analyze mechanisms underlying modulation by N‐methyl‐d‐aspartate (NMDA) receptors of proliferation of neural progenitor cells in adult mouse brain. The systemic administration of NMDA at 100 mg/kg resulted in marked expression of c‐Fos, Fra‐2 and c‐Jun proteins in the granule cell layers of the dentate gyrus in murine hippocampus 2 h later, followed by a significant reduction of the incorporation of 5‐bromo‐2′‐deoxyuridine (BrdU) in a manner sensitive to the antagonist dizocilpine 2 days after administration. The administration of NMDA also suppressed constitutive expression of both nestin and proliferating cell nuclear antigen (PCNA) in the dentate granule cells 2 days later, without markedly affecting cell viability for up to 8 weeks after administration. In the subventricular zone and olfactory bulb, however, NMDA failed to affect either the incorporation of BrdU or the expression of nestin and PCNA. The NR1 subunit was highly expressed in the dentate gyrus in addition to the stratum oriens in the hippocampus, but not in the subventricular zone and olfactory bulb. These results suggest that NMDA receptors may play a role crucial for maintenance of the integrity and function of proliferative neural progenitor cells through expression of the nuclear transcription factor activator protein‐1 in granule cells of the dentate gyrus in adult mouse brain.
Factors associated with the self‐care of home‐dwelling elderly
Authors: Backman Kaisa , Hentinen Maija
Published: March 2003

Factors associated with the self‐care of home‐dwelling elderly

The purpose of this study was to examine how functional capacity, activities of daily living (ADL), instrumental activities of daily living (IADL), life satisfaction and self‐esteem are related to the self‐care behaviour styles of home‐dwelling elderly persons. Data were collected by qualitative interviews (self‐care) and structured interviews (functional capacity, life satisfaction and self‐esteem) from home‐dwelling elderly persons (n=40) aged 75 or more. The persons were living in a medium‐sized city in northern Finland. The qualitative data were analysed using deductive content analysis. The classification frame consisted of a theoretical classification developed in an earlier study. The categories were quantified and the relationship between the variables analysed by cross‐tabulation. The persons whose self‐care behaviour style was responsible, formally guided or independent carried out their daily activities without assistance from others, while those who showed abandoned self‐care did not manage their daily activities without help. Life satisfaction was the highest among the formally guided persons and self‐esteem among the responsible ones. Poor life satisfaction and self‐esteem correlated with abandoned self‐care behaviour.
The general health in women suffering from gynaecological disorders is improved by means of hysterectomy
Authors: Rannestad Toril , Eikeland Ole‐Johan , Helland Harald , Qvarnström Ulla
Published: March 2003

The general health in women suffering from gynaecological disorders is improved by means of hysterectomy

Gynaecological disorders can have adverse effects on women’s general health, and for a substantial number of these women hysterectomy is performed. This study aims to evaluate the long‐term impact of hysterectomy on this outcome variable. The patient‐group was tested pre‐operatively and 6 and 12 months after hysterectomy. The control‐group was tested once. This study shows that the general health in women suffering from gynaecological disorders is significantly lower compared with that of the control‐group (p < 0.00). Both 6 and 12 months after the hysterectomy, however, the patient‐group has reached the same level of their general health as the control‐group. Twenty‐eight per cent of their potentiality for improved health has been obtained. For those women with poorest health both pre‐ and postoperatively, other factors than the hysterectomy have had a negative impact on their general health and lives. The results from this study suggest that hysterectomy is associated with a positive long‐term impact on women’s general health.
Do occupational therapy and physiotherapy students care about research? A survey of perceptions and attitudes to research
Authors: Kamwendo Kitty , Törnquist Kristina
Published: March 2003

Do occupational therapy and physiotherapy students care about research? A survey of perceptions and attitudes to research

In this cross‐sectional study, we have used a questionnaire to study perceptions and attitudes to research‐related activities of Swedish occupational therapy and physiotherapy first (T1) and final term (T6) students. Two hundred and eleven students from programmes employing either problem‐based learning (PBL) or traditional education methods participated. The results showed that students had a positive attitude towards research, particularly for the activity ‘read research literature to update knowledge’ and ‘apply research findings to improve practice’. When T1 were compared with T6 students, the ability to perform research‐related activities was rated significantly higher by T6 students regardless of educational methods. A comparison of PBL and the traditional educational method resulted in moderate but significant differences. The PBL students had a more positive attitude towards research and to a greater extent intended to engage in research activities in the future. The results give hope for a positive future development of the occupational therapy and physiotherapy professions and a PBL education method may be more conducive to the shaping of a research consumer than a traditional method, although more research is needed to substantiate these claims.
Patient reported quality of care before vs. after the implementation of a diagnosis related groups (DRG) classification and payment system in one Swedish county
Authors: Ljunggren Birgitta , Sjödén Per‐Olow
Published: March 2003

Patient reported quality of care before vs. after the implementation of a diagnosis related groups (DRG) classification and payment system in one Swedish county

The purpose was to evaluate the effects of a diagnosis related groups (DRG)‐intervention on the quality of care as perceived by patients at two surgical clinics in the County Council of Gävleborg, Sweden. The study was planned as a nonequivalent control groups design, but external factors turned it into a prospective longitudinal design. Changes in patient experiences of received care were evaluated for the period 1992–1996. Of the 40 included consecutive patients per year from each hospital, > 85% completed the questionnaire. The selection of patients was defined by diagnoses and surgical treatments, and by geographical area. The results demonstrated a decrease of the quality of care as seen from the patient perspective, especially with respect to treatment by staff. Previously stated DRG goals were partially fulfilled and the DRG‐intervention was gradually implemented. Other presumed causal variables were: other reforms, restrained resources, quality assurance activities, organizational and structural changes within the county council. Further studies of the effects of health care reforms would yield more distinct conclusions, provided it would be possible to evaluate interventions prior to full‐scale implementation.
The patient's narrative of suffering: a path to health?
Authors: Fredriksson Lennart , Eriksson Katie
Published: March 2003

The aim of this interpretative research synthesis was to develop a theoretical understanding of how a narrative approach in a caring conversation enables the patient to understand and find meaning in suffering, and how this in turn may be a path to health. The material consisted of 23 articles published between 1990 and 1997 in caring and nursing journals. The synthesis is summed up in a model for narrative understanding in a caring conservation consisting of three phases in which the patient is encouraged:(i) to tell stories describing why the suffering has come about, how things are at present, and what is wanted and needed; (ii)to make up a narrative of suffering that follows the actual course of events; and (iii) to reconnect to their life history, that is to reflect on the point or lesson to be learned in order to achieve a new wholeness. The model may be linked with and used in the clinical setting, and it also raises questions for further research in the area of communication in health care.
Men's descriptions of their experience of nonmalignant pain of fibromyalgia type
Authors: Paulson Margareta , Danielson Ella , Larsson Kenneth , Norberg Astrid
Published: March 2003

The purpose of this study was to gather men's descriptions of their experience of nonmalignant pain of fibromyalgia (FM) type in order to gain a deeper understanding of this phenomenon. Fourteen men participated in the study. A qualitative method with narrative interviews and content analysis were used. The findings showed that the men's experience of pain fell within two major themes: ‘perceptions of diversified bodily pain’ and ‘perceptions of fluctuating pain’. The pain had progressed from being local to being widespread. Characteristic was that the men described both pain that worried them and pain that did not worry them and also that the pain passed through both calm and difficult phases. This study highlights the importance of acknowledgement that men had specific experiences and used metaphorical expressions to make the pain visible. The clinical indication in this study is that health care staff need to listen intently to each man's narrative and learn to interpret the descriptions of their experience of long‐term pain that involve a great variety of both bodily and emotional symptoms. These findings are a crucial prerequisite for the health care staff's possibility to offer support and relief to men with pain of FM type.
Nurses' experiences of abusive/non‐abusive caring for demented patients in acute care settings
Authors: Eriksson Catharina , Saveman Britt‐Inger
Published: March 2003

Nurses' experiences of abusive/non‐abusive caring for demented patients in acute care settings

Nurses caring for patients with dementia in acute care settings often lack specialized education in geriatric nursing. The acute care settings do not have an environment made for dementia care. The staff often had a high workload, which makes the situation stressful and the nurses who take care of these patients might end up in difficult situations. The aim of this study was to describe nurses' experiences of difficulties related to caring for patients with dementia in acute care settings. Interviews were performed with 12 nurses. Qualitative thematic content analyses were carried out in several steps. The results show that the nurses experienced various difficulties in meeting patients with dementia in acute care settings. This gave rise to for example frustration. Most commonly reported was lack of time to treat these patients satisfactorily. The difficulties were mostly related to the often disorderly conduct of these patients, the ethical problems that appeared in the care of these patients, and the medical care organization. The problematic situations described sometimes led to abuse and neglect of these patients.
Assessment of pain, depression, and anxiety by visual analogue scale in Japanese women with rheumatoid arthritis
Authors: Tamiya Nanako , Araki Shunichi , Ohi Gen , Inagaki Katsuhiko , Urano Naoko , Hirano Wataru , Daltroy Lawren Hugh
Published: March 2003

Assessment of pain, depression, and anxiety by visual analogue scale in Japanese women with rheumatoid arthritis

Visual analogue scales (VAS) of depression and anxiety were compared with standard full‐length measures of these variables and with VAS of pain (VAS Pain). This was a good way to develop a practical methodology for the routine assessment of pain and affect in rheumatoid arthritis (RA) patients. The reliability of VAS Pain was studied by test–retest. The validity of VAS Pain in our sample was proved by correlations with the results of other tests. We also investigated the relationship between VAS Pain and C‐reactive protein (CRP).

In 145 female RA patients, VAS of depression and anxiety were significantly correlated with full‐length measures of these variables, and accounted for the majority of the explained variance in VAS Pain, while the full‐length standard measures contributed little more.

In conclusion, VAS measurements of pain and affect were comprehensible, easily filled‐out, and reliable in a sample of Japanese women with RA, and could capture some aspect of affective distress unique to RA patients.
Exceptional nontraditional caring practices of nurses
Authors: Yonge Olive , Molzahn Anita
Published: March 2003

There has been little research that has addressed the practices of nurses who go beyond the usual scope of practice to demonstrate caring. In this study, a grounded theory methodology was used to interview 18 nurses identified as exceptional caring nurses. The core process identified was giving and involved gifts (particularly of time), responsibility and choice, teaching, vulnerability, preserving dignity, caring with and for coworkers, being truly present, and always finding a way. Although the findings of this study are not necessarily generalizable, it is important to acknowledge that these practices occur and that they should not automatically be discredited. The research has implications for the new emerging field of boundaries in professional relationships.
Care dependency: testing the German version of the care dependency scale in nursing homes and on geriatric wards
Authors: Lohrmann Christa , Dijkstra Ate , Dassen Theo
Published: March 2003

The purpose of this study was the psychometric evaluation of the German version of the dependency scale in nursing homes and on geriatric wards. The 15‐item scale was originally developed in the Netherlands for assessing the care dependency of demented and mentally handicapped patients. Data of 81 nursing home residents and of 115 geriatric patients were collected. Residents and patients were assessed several time by professionals and nonprofessionals. Reliability was determined by Cronbach's α, showing very good results with values of 0.94 and 0.98. Inter‐rater and intrarater reliability show moderate to substantial Kappa values. Criterion validity was examined by comparing the data of the scale with the German nursing personal regulation and the German statutory insurance. The results show that the scores of the Care Dependency Scale correlate to the scores of the two classifications. In general, the German version of the scale can be recommended for use in nursing homes and on geriatric wards.
Meaning of dependency on care as narrated by nurses
Authors: Strandberg Gunilla , Jansson Lilian
Published: March 2003

This article is part of an ongoing study aimed at illuminating the meaning of dependency on care. The aim of this particular study is to illuminate the meaning of the phenomenon ‘dependency on care’ as narrated by nurses. Interviews with 20 nurses were conducted, tape‐recorded and transcribed verbatim. A phenomenological‐hermeneutic approach was used to interpret the data. The meaning of dependency on care is revealed as laborious for both patients and nurses. The nurses' text discloses that for patients, dependency on care is a miserable loss of self‐determination and self‐worth. Nurses appear to be moved by dependants' difficult life and want to do whatever they can for the dependant. Dependency on care is a burdensome responsibility for nurses. For nurses dependency on care is revealed as evoking feelings of guilt and insufficiency and of being constantly concerned and worried. It is to struggle to be patient and understanding, having the arduous task of putting oneself into the dependent patients' shoes in order to cope with the demanding task of balancing between helping and not helping too much. The interpretation discloses, however, that nurses distinguish between easy and trying dependency on care. The understanding indicates that when they meet ‘good’ patients, nurses reappraise the situation, transform it into something new and meaningful, that is dependency on care is disclosed as ‘easy to take’. When coming across‘difficult’ patients dependency on care is disclosed as trying. It seems that within the unique nurse–patient relationship patients may participate in such a way as to facilitate or inhibit nurses in finding meaning in the immediate caregiving situation. Nurses' evaluations of what constitutes a ‘good’ or a ‘difficult’ patient, respectively, seem to play an important role in distinguishing between dependency on care that is easy and that which is trying. The result is viewed through an existential paradigm and there is also reflection about what nurses perceive as valuable qualities in patients which might influence the quality of care.
Characterization of microsatellite loci in the endangered St. Vincent Parrot, Amazona guildingii
Authors: Russello M. , Calcagnotto D. , DeSalle R. , Amato G.
Published: March 2003

Microsatellite loci were isolated within the St Vincent parrot (Amazona guildingii), an endangered island endemic, from a GTn enriched genomic library. Nine polymorphic loci were characterized varying from two to nine alleles per locus. Seven loci exhibited levels of heterozygosity ranging from 39 to 100% within the 28 individuals genotyped. Furthermore, the primers were demonstrated to cross‐amplify within four genera of Neotropical parrots, indicating the potential utility of these markers to further population‐level studies and conservation efforts of New World Psittacines.
Characterization of microsatellite loci in Tursiops aduncus
Authors: Krützen M. , Valsecchi E. , Connor R. C. , Sherwin W. B.
Published: March 2003

We describe the cloning and characterization of five highly polymorphic microsatellite loci cloned from aduncus dolphins (Tursiops aduncus) from Western Australia. Five polymorphic microsatellite loci were isolated and tested on up to 350 animals, showing 7–23 alleles and expected heterozygosity values from 0.68 to 0.89. We also tested the loci on striped dolphins and franciscana dolphins, where we also found high levels of polymorphism (9–16 alleles in 102 striped, and 4–5 alleles in 13 franciscana dolphins). Considering that the cetacean genome is highly conserved, the characterized markers are likely to be useful in a number of cetacean population studies.
Development of microsatellite markers in the Japanese pear (Pyrus pyrifolia Nakai)
Authors: Yamamoto T. , Kimura T. , Shoda M. , Ban Y. , Hayashi T. , Matsuta N.
Published: March 2003

Thirteen polymorphic microsatellite loci were developed in the Japanese pear (Pyrus pyrifolia Nakai) by using an enriched genomic library. The obtained microsatellite loci showed a high degree of polymorphism in the Japanese pear with 3–6 alleles per locus. The average values of observed and expected heterozygosities among these 13 loci were 0.69 and 0.71, respectively. Ten microsatellites could successfully amplify loci in the European pear (Pyrus communis L.), which were highly polymorphic as well.
gemini: software for testing the effects of genotyping errors and multitubes approach for individual identification
Authors: Valière Nathaniel , Berthier Pierre , Mouchiroud Dominique , Pontier Dominique
Published: March 2003

Improvements in the determination of individual genotypes from samples with low DNA quantity and quality are of prime importance in molecular ecology and conservation for reliable genetic individual identification (molecular tagging using microsatllites loci). Thus, errors (e.g. allelic dropout and false allele) appearing during samples genotyping must be monitored and eliminated as far as possible. The multitubes approach is a very effective but a costly and time‐consuming solution. In this paper, we present a simulation software that allows evaluation of the effect of genotyping errors on genetic identification of individuals and the effectiveness of a multitubes approach to correct these errors.