bluuebunny/crossref_metadata_2025 huggingface dataset:
Identity of adenylyl cyclase isoform determines the G protein mediating chronic opioid‐induced adenylyl cyclase supersensitivity
Authors: Ammer Hermann , Christ Thomas E.
Published: March 2003

To determine the intracellular signal transduction pathway responsible for the development of tolerance/dependence, the ability of Gzα to substitute for pertussis toxin (PTX)‐sensitive G proteins in mediating adenylyl cyclase (AC) supersensitivity was examined in the presence of defined AC isoforms. In transiently µ‐opioid receptor (OR) transfected COS‐7 cells (endogenous inhibitory G proteins: Giα2, Giα3 and Gzα), neither acute (1 µmol/L) nor chronic morphine treatment (1 µmol/L; 18 h) influenced intracellular cAMP production. Coexpression of the µ‐OR together with AC type V and VI fully restored the ability of morphine to acutely inhibit cAMP generation. Chronic morphine treatment further resulted in the development of tolerance/dependence, as assessed by desensitization of the acute inhibitory opioid effect (tolerance) as well as the induction of AC supersensitivity after drug withdrawal (dependence). Specific direction of µ‐OR signalling via Gzα by both PTX treatment and Gzα over‐expression had no effect on chronic morphine regulation of AC type V, but completely abolished the development of tolerance/dependence with AC type VI. Similar results were obtained in stably µ‐OR‐expressing HEK293 cells transiently cotransfected with Gzα and either AC type V or VI. Coprecipitation studies further verified that Gzα specifically binds to AC type V but not type VI. Taken together, these results demonstrate that in principle each of the OR‐activated G proteins per se is able to mediate AC supersensitivity. However, they also indicate that it is the molecular nature of AC isoform that selects and determines the OR‐activated G protein mediating tolerance/dependence.
TorsinA and heat shock proteins act as molecular chaperones: suppression of α‐synuclein aggregation
Authors: McLean Pamela J. , Kawamata Hibiki , Shariff Saadat , Hewett Jeffrey , Sharma Nutan , Ueda Kenji , Breakefield Xandra O. , Hyman Bradley T.
Published: March 2003

TorsinA, a protein with homology to yeast heat shock protein104, has previously been demonstrated to colocalize with α‐synuclein in Lewy bodies, the pathological hallmark of Parkinson's disease. Heat shock proteins are a family of chaperones that are both constitutively expressed and induced by stressors, and that serve essential functions for protein refolding and/or degradation. Here, we demonstrate that, like torsinA, specific molecular chaperone heat shock proteins colocalize with α‐synuclein in Lewy bodies. In addition, using a cellular model of α‐synuclein aggregation, we demonstrate that torsinA and specific heat shock protein molecular chaperones colocalize with α‐synuclein immunopositive inclusions. Further, overexpression of torsinA and specific heat shock proteins suppress α‐synuclein aggregation in this cellular model, whereas mutant torsinA has no effect. These data suggest that torsinA has chaperone‐like activity and that the disease‐associated GAG deletion mutant has a loss‐of‐function phenotype. Moreover, these data support a role for chaperone proteins, including torsinA and heat shock proteins, in cellular responses to neurodegenerative inclusions.
Proteasomal inhibition by misfolded mutant superoxide dismutase 1 induces selective motor neuron death in familial amyotrophic lateral sclerosis
Authors: Urushitani Makoto , Kurisu Junko , Tsukita Kayoko , Takahashi Ryosuke
Published: March 2003

Accumulating evidence indicates that abnormal conformation of mutant superoxide dismutase 1 (SOD1) is an essential feature underlying the pathogenesis of mutant SOD1‐linked familial amyotrophic lateral sclerosis (ALS). Here we investigated the role of ubiquitin‐proteasome pathway in the mutant SOD1‐related cell death and the effect of oxidative stress on the misfolding of mutant SOD1. Transient overexpression of ubiquitin with human SOD1 (wild‐type, ala4val, gly85arg, gly93ala) in Neuro2A cells decreased the amount of mutant SOD1, but not of wild‐type, while only mutants were co‐immunoprecipitated with poly‐ubiquitin. Proteasome inhibition by lactacystin augmented accumulation of mutant SOD1 in the non‐ionic detergent‐insoluble fraction. The spinal cord lysates from mutant SOD1 transgenic mice showed multiple carbonylated proteins, including mutant SOD1 with SDS‐resistant dimer formation. Furthermore, the treatment of hSOD1‐expressing cells with hydrogen peroxide promoted the oligomerization, and detergent‐insolubility of mutant SOD1 alone, and the oxidized mutant SOD1 proteins were more heavily poly‐ubiquitinated. In Neuro2A cells stably expressing human SOD1 protein, the proteasome function measured by chymotrypsin‐like activity, was decreased over time without a quantitative alteration of the 20S proteasomal component. Finally, primary motor neurons from the mouse embryonic spinal cord were more vulnerable to lactacystin than non‐motor neurons. These results indicate that the sustained expression of mutant SOD1 leads to proteasomal inhibition and motor neuronal death, which in part explains the pathogenesis of mutant SOD1‐linked ALS.
Norepinephrine alters the expression of genes involved in neuronal sprouting and differentiation: relevance for major depression and antidepressant mechanisms
Authors: Laifenfeld Daphna , Klein Ehud , Ben‐Shachar Dorit
Published: March 2003

Recent research into depression has focused on the involvement of long‐term intracellular processes, leading to abnormal neuronal plasticity in brains of depressed patients, and reversed by antidepressant treatment. Given a suggested decrease in noradrenergic transmission in depression, and an antidepressant induced increase in norepinephrine (NE) level, a possible role for NE in mediating alterations in neuronal morphology and plasticity was examined. Human neuroblastoma SH‐SY5Y cells treated with 10−5 m NE presented an elongated granule‐rich cell‐body and increased number of neurites, when compared with non‐treated cells. Moreover, cell survival was enhanced in the presence of NE, while proliferation was inhibited. The above effects suggest a role for NE in cell differentiation. Indeed similar effects on cell survival and neurite outgrowth were induced in SH‐SY5Y cells by retinoic acid (RA), an established differentiating agent. Finally, NE treatment resulted in a progressive decrease in the pluripotent marker Oct4 and an increase in the neuronal growth cone marker, growth‐associated‐protein 43 (GAP‐43). Alongside these effects, NE‐treated cells presented alterations in the expression of 44 genes as observed in a neurobiology cDNA microarray. Among the altered genes, an increase in the expression level of two neurite‐outgrowth promoting genes, neural cell adhesion molecule L1 and laminin, was confirmed by RT‐PCR. Taken together, the results support a role for NE in processes of synaptic connectivity, and may point to a role for this neurotransmitter in mediating the suggested neuronal plasticity in depression and in antidepressant treatment.
Progesterone enhances ethanol‐induced modulation of mesocortical dopamine neurons: antagonism by finasteride
Authors: Dazzi Laura , Serra Mariangela , Seu Emanuele , Cherchi Giulia , Pisu M. Giuseppina , Purdy Robert H. , Biggio Giovanni
Published: March 2003

The effect of endogenous 3α‐hydroxy‐5α‐pregnan‐20‐one (3α,5α‐TH PROG) on the modulation of mesocortical dopamine extracellular concentration by ethanol was investigated by microdialysis in rats. Intraperitoneal injection of progesterone (5 mg/kg, once a day for 5 days) increased the cortical content of 3α,5α‐TH PROG and potentiated the biphasic effect of acute intraperitoneal administration of ethanol on dopamine content. A dose of ethanol (0.25 g/kg) that was ineffective in naïve rats induced a 55% increase in dopamine extracellular concentration in rats pretreated with progesterone. This increase was similar to that induced by a higher dose (0.5 g/kg) of ethanol in naïve rats. Administration of ethanol at 0.5 g/kg to progesterone‐pretreated rats inhibited dopamine content by an extent similar to that observed with an even higher dose (1 g/kg) in naïve rats. The administration of the 5α‐reductase inhibitor finasteride (25 mg/kg, subcutaneous), together with progesterone, prevented the effects of the latter, both on the cortical concentration of 3α,5α‐TH PROG and on the modulation by ethanol of dopamine content. These data suggest that 3α,5α‐TH PROG contributes to the action of ethanol on the mesocortical dopaminergic system. They also suggest that physiological fluctuations in the brain concentrations of neuroactive steroids associated with the oestrous cycle, menopause, pregnancy and stress may alter the response of mesocortical dopaminergic neurons to ethanol.
Quantitative relationship between inhibition of respiratory complexes and formation of reactive oxygen species in isolated nerve terminals
Authors: Sipos Ildikó , Tretter Laszlo , Adam‐Vizi Vera
Published: March 2003

In this study reactive oxygen species (ROS) generated in the respiratory chain were measured and the quantitative relationship between inhibition of the respiratory chain complexes and ROS formation was investigated in isolated nerve terminals. We addressed to what extent complex I, III and IV,respectively, should be inhibited to cause ROS generation. For inhibition of complex I, III and IV, rotenone, antimycin and cyanide were used, respectively, and ROS formation was followed by measuring the activity of aconitase enzyme. ROS formation was not detected until complex III was inhibited by up to 71 ± 4%, above that threshold inhibition, decrease in aconitase activity indicated an enhanced ROS generation. Similarly, threshold inhibition of complex IV caused anaccelerated ROS production. By contrast, inactivation of complex I to a small extent (16 ± 2%) resulted in a significant increase in ROS formation, and no clear threshold inhibition could be determined. However, the magnitude of ROS generated at complex I when it is completely inhibited is smaller than that observed when complex III or complex IV was fully inactivated. Our findings may add a novel aspect to the pathology of Parkinson's disease, showing that a moderate level of complex I inhibition characteristic in Parkinson's disease leads to significant ROS formation. The amount of ROS generated by complex I inhibition is sufficient to inhibit in situ the activity of endogenous aconitase.
Degraded myelin‐associated glycoprotein (dMAG) formation from pure human brain myelin‐associated glycoprotein (MAG) is not mediated by calpain or cathepsin L‐like activities
Authors: Päiväläinen Satu , Suokas Marko , Lahti Outi , Heape Anthony M.
Published: March 2003

The myelin‐associated glycoprotein (MAG) is a transmembrane cell adhesion molecule participating in myelin formation and maintenance. Calcium‐activated/‐dependent proteolysis of myelin‐associated glycoprotein by calpain and cathepsin L‐like activities has already been detected in purified myelin fractions, producing a soluble fragment, called degraded (d)MAG, characterized by the loss of the transmembrane and cytoplasmic domains. Here, we demonstrate and analyze dMAG formation from pure human brain myelin‐associated glycoprotein. The activity never exhibited the high rate previously reported in human myelin fractions. Degradation is time‐, temperature‐, buffer‐ and structure‐dependent, is inhibited at 4°C and by denaturation of the sample, and is mediated by a trans‐acting factor. There is no strict pH dependency of the proteolysis. Degradation was inhibited by excess aprotinin, but not by 1–10 µg/mL aprotinin and was not eliminated by the use of an aprotinin‐sepharose matrix during the purification. dMAG formation was not enhanced by calcium, nor inhibited by a wide variety of protease inhibitors, including specific calpain and cathepsin L inhibitors. Therefore, while cysteine proteases may be present in human myelin membrane fractions, they are not involved in dMAG formation from highly purified human brain myelin‐associated glycoprotein preparations.
Transients in acetylcholine receptor site density and degradation during reinnervation of mouse sternomastoid muscle
Authors: Szabo Maria , Salpeter Edwin E. , Randall William , Salpeter Miriam M.
Published: March 2003

The degradation rates of acetylcholine receptors (AchRs) were evaluated at the neuromuscular junction during and just after reinnervation of denervated muscles. When mouse sternomastoid muscles are denervated by multiple nerve crush, reinnervation begins 2–4 days later and is complete by day 7–9 after the last crush. In fully innervated muscles, the AChR degradation rate is stable and slow (t1/2 ≈ 10 days), whereas after denervation the newly inserted receptors degrade rapidly (t1/2 ≈ 1.2 days). The composite profile of degradation, which a mixture of the stable and the rapid receptors would give, is not observed during reinnervation. Instead, the receptors inserted between 2.5 and 7.5 days after the last crush all have an intermediate degradation rate of t1/2 ≈ 3.7 days with standard error ± 0.3 days. The total receptor site density at the endplate was evaluated during denervation and during reinnervation. As predicted theoretically, the site density increased substantially, but temporarily, after denervation. An analogous deleterious substantial decrease in density would be expected during reinnervation, without the intermediate receptor. This decrease is not observed, however, because of a large insertion rate at intermediate times (3000 ± 700 receptor complexes per µm2 per day). The endplate density of receptors thus remains relatively constant.
Far‐upstream elements are dispensable for tissue‐specific proenkephalin expression using a Cre‐mediated knock‐in strategy
Authors: Le Yunzheng , Gagneten Sara , Larson Teresa , Santha Edit , Dobi Albert , Agoston Denes v. , Sauer Brian
Published: March 2003

Several cis‐regulatory DNA elements are present in the 5′ upstream regulatory region of the enkephalin gene (ENK) promoter. To determine their role in conferring organ‐specificity of ENK expression in mice and to circumvent the position effects from random gene insertion that are known to often frustrate such analysis in transgenic mice, we used a Cre‐mediated gene knock‐in strategy to target reporter constructs to a ‘safe haven’loxP‐tagged locus in the hypoxanthine phosphoribosyltransferase (HPRT) gene. Here we report reliable and reproducible reporter gene expression under the control of the 5′ upstream regulatory region of the mouse ENK gene in gene‐modified mice using this Cre‐mediated knock‐in strategy. Comparison of two 5′ENK regulatory regions (one with and the other without known cis‐regulatory DNA elements) in the resulting adult mice showed that conserved far‐upstream cis‐regulatory DNA elements are dispensable for correct organ‐specific gene expression. Thus the proximal 1.4 kb of the murine ENK promoter region is sufficient for organ‐specificity of ENK gene expression when targeted to a safe‐haven genomic locus. These results suggest that conservation of the far‐upstream DNA elements serves more subtle roles, such as the developmental or cell‐specific expression of the ENK gene.
Nicotine trapping causes the persistent desensitization of α4β2 nicotinic receptors expressed in oocytes
Authors: Jia Li , Flotildes Karen , Li Maureen , Cohen Bruce N.
Published: March 2003

To determine whether prolonged nicotine exposure persistently inactivates rat α4β2 nicotinic receptors expressed in Xenopus oocytes, we measured the voltage‐clamped α4β2 response to acetylcholine (ACh) before and 24 h after, 1‐h or 12‐h incubations in 10 µm nicotine. A 12‐h incubation in 10 µm nicotine depressed the α4β2 ACh response for 24 h without affecting total or surface α4β2 expression. To determine whether oocyte‐mediated nicotine release caused this depression, we co‐incubated an α4β2‐expressing oocyte with an un‐injected one (pre‐incubated in 10 µm nicotine for 12 h) for 24 h and measured the change in the α4β2 ACh response. The response decreased by the same factor after the co‐incubation as it did after a 12‐h incubation in 10 µm nicotine and a 24‐h incubation in nicotine‐free media. Thus, oocyte‐mediated nicotine release caused the persistent desensitization we observed after a 12‐h incubation in 10 µm nicotine. Consistent with this result, measurements of [3H]nicotine release show that oocytes release enough nicotine into the wash media to desensitize α4β2 receptors and that prolonged incubation in 300 µm ACh (which cannot readily cross the membrane or accumulate in acidic vesicles) did not persistently depress the α4β2 response.
BDNF heightens the sensitivity of motor neurons to excitotoxic insults through activation of TrkB
Authors: Hu Peter , Kalb Robert G.
Published: March 2003

The survival promoting and neuroprotective actions of brain‐derived neurotrophic factor (BDNF) are well known but under certain circumstances this growth factor can also exacerbate excitotoxic insults to neurons. Prior exploration of the receptor through which BDNF exerts this action on motor neurons deflects attention away from p75. Here we investigated the possibility that BDNF acts through the receptor tyrosine kinase, TrkB, to confer on motor neurons sensitivity to excitotoxic challenge. We blocked BDNF activation of TrkB using a dominant negative TrkB mutant or a TrkB function blocking antibody, and found that this protected motor neurons against excitotoxic insult in cultures of mixed spinal cord neurons. Addition of a function blocking antibody to BDNF to mixed spinal cord neuron cultures is also neuroprotective indicating that endogenously produced BDNF participates in vulnerability to excitotoxicity. We next examined the intracellular signaling cascades that are engaged upon TrkB activation. Previously we found that inhibition of the phosphatidylinositide‐3′‐kinase (PI3′K) pathway blocks BDNF‐induced excitotoxic sensitivity. Here we show that expression of a constitutively active catalytic subunit of PI3′K, p110, confers excitotoxic sensitivity (ES) upon motor neurons not incubated with BDNF. Parallel studies with purified motor neurons confirm that these events are likely to be occuring specifically within motor neurons. The abrogation of BDNF's capacity to accentuate excitotoxic insults may make it a more attractive neuroprotective agent.
Analysis of phospholipid molecular species in brains from patients with infantile and juvenile neuronal‐ceroid lipofuscinosis using liquid chromatography‐electrospray ionization mass spectrometry
Authors: Käkelä Reijo , Somerharju Pentti , Tyynelä Jaana
Published: March 2003

Phospholipids (PL) in cerebral cortex from patients with infantile (INCL or CLN1) and juvenile (JNCL or CLN3) forms of neuronal ceroid‐lipofuscinosis (NCL) and controls were analysed by normal phase HPLC and on‐line electrospray ionization ion‐trap mass spectrometric detection (LC‐ESI‐MS). The method provided quantitative data on numerous molecular species of different PL classes, which are not achieved by using the conventional chromatographic methods. Compared with the controls, the INCL brains contained proportionally more phosphatidylcholine (PC), and less phosphatidylethanolamine (PE) and phosphatidylserine (PS). Different molecular species of PC, PE, PS, phosphatidylinositol and sphingomyelin were quantified using multiple internal PL standards that differed in fatty acyl chain length and thus allowed correction for chain length dependency of instrument response. In INCL cortex, which had lost 65% of the normal PL content, the proportions of polyunsaturated molecular species, especially the PS and PE that contained docosahexaenoic acid (22:6n‐3), were dramatically decreased. The membranes may have adapted to this alteration by increasing the proportions of PL molecules substituted with monounsaturated and short‐chain fatty acids. Lysobisphosphatidic acid was highly elevated in the INCL brain and consisted mostly of polyunsaturated species. It is possible that changes in the composition of PL membranes accelerate progression of INCL by altering signalling and membrane trafficking in neurons.
Characterization of the functional role of the N‐glycans in the AMPA receptor ligand‐binding domain
Authors: Pasternack Arja , Coleman Sarah K. , Féthière James , Madden Dean R. , LeCaer Jean‐Pierre , Rossier Jean , Pasternack Michael , Keinänen Kari
Published: March 2003

The ligand‐binding domains of AMPA receptor subunits carry two conserved N‐glycosylation sites. In order to gain insight into the functional role of the corresponding N‐glycans, we examined how the elimination of glycosylation at these sites (N407 and N414) affects the ligand‐binding characteristics, structural stability, cell‐surface expression, and channel properties of homomeric GluR‐D (GluR4) receptor and its soluble ligand‐binding domain (S1S2). GluR‐D S1S2 protein expressed as a secreted protein in insect cells was found to be glycosylated at N407 and N414. No major differences in the ligand‐binding properties were observed between the ‘wild‐type’ S1S2 and non‐glycosylated N407D/N414Q double mutant, or between S1S2 proteins expressed in the presence or absence of tunicamycin, an inhibitor of N‐glycosylation. Purified glycosylated and non‐glycosylated S1S2 proteins also showed similar thermostabilities as determined by CD spectroscopy. Full‐length homomeric GluR‐D receptor with N407D/N414Q mutation was expressed on the surface of HEK293 cells like the wild‐type GluR‐D. In outside‐out patches, GluR‐D and the N407D/N414Q mutant produced similar rapidly desensitizing current responses to glutamate and AMPA. We therefore report that the two conserved ligand‐binding domain glycans do not play any major role in receptor–ligand interactions, do not impart a stabilizing effect on the ligand‐binding domain, and are not critical for the formation and surface localization of homomeric GluR‐D AMPA receptors in HEK293 cells.
The apoptosis/necrosis transition in cerebellar granule cells depends on the mutual relationship of the antioxidant and the proteolytic systems which regulate ROS production and cytochrome c release en route to death
Authors: Atlante Anna , Bobba Antonella , Calissano Pietro , Passarella Salvatore , Marra Ersilia
Published: March 2003

We investigate the death route induced by potassium depletion in cerebellar granule cells in 0–15 h time range and study whether and how mutual relationship occurs between the cell antioxidant and proteolytic system. To achieve this, we incubated cells in the absence or presence of inhibitors of the antioxidant system, including superoxide dismutase and catalase, and of the proteolytic system, consisting of proteasomes and caspases, and investigated whether and how (i) cell survival, (ii) reactive oxygen species (ROS) production and (iii) antioxidant enzyme and caspase‐3 activity change as a function of time after the apoptotic stimulus. The involvement of both antioxidant and proteolytic system on cytochrome c release was also investigated. Cell survival was found to increase in the presence of either proteasome or caspase inhibitors. On the contrary, as a result of the antioxidant system impairment, shift from apoptosis to necrosis occurs. We show that the antioxidant system, which exhibits a huge activity increase up to 3 h after apoptosis induction, is subjected to the proteasome‐dependent proteolysis and that the increase in the antioxidant system found in the absence of proteasome activity is accompanied by ROS production decrease. Consistently, the early ROS‐dependent release of cytochrome c was found to be prevented when the activity of the antioxidant system increased. Finally, caspase‐3 activation was prevented by the inhibitors of both antioxidant system and proteasome.
Molecular changes in fetal Down syndrome brain
Authors: Engidawork Ephrem , Lubec Gert
Published: March 2003

Trisomy of human chromosome 21 is a major cause of mental retardation and other phenotypic abnormalities collectively known as Down syndrome. Down syndrome is associated with developmental failure followed by processes of neurodegeneration that are known to supervene later in life. Despite a widespread interest in Down syndrome, the cause of developmental failure is unclear. The brain of a child with Down syndrome develops differently from that of a normal one, although characteristic morphological differences have not been noted in prenatal life. On the other hand, a review of the existing literature indicates that there are a series of biochemical alterations occurring in fetal Down syndrome brain that could serve as substrate for morphological changes. We propose that these biochemical alterations represent and/or precede morphological changes. This review attempts to dissect these molecular changes and to explain how they may lead to mental retardation.
Serotonin catabolism depends upon location of release: characterization of sulfated and γ‐glutamylated serotonin metabolites in Aplysia californica
Authors: Stuart Jeffrey N. , Zhang Xin , Jakubowski Jennifer A. , Romanova Elena V. , Sweedler Jonathan V.
Published: March 2003

Serotonin is a vital neurotransmitter for the functioning of the nervous system in species throughout the animal phyla. Despite its ubiquitous nature, the metabolism of this molecule has yet to be completely elucidated in even the most basic of organisms. Two novel serotonin catabolites, serotonin‐O‐sulfate and γ‐glu‐serotonin‐O‐sulfate, are chemically characterized using capillary electrophoresis with wavelength‐resolved fluorescence detection and electrospray mass spectrometry, and the formation of γ‐glu‐serotonin in Aplysia californica is confirmed. These novel compounds appear to be synthesized enzymatically, and known mammalian enzymes exist for all serotonin transformations observed here. The pathway of serotonin inactivation depends upon the type of neuronal tissue subjected to neurotransmitter incubation, with assorted serotonin products observed in distinct locations. Initially demonstrated to be in the metacerebral cell (MCC) soma, the new serotonin metabolite serotonin‐O‐sulfate may contribute to important functions in the serotonergic system beyond simple serotonin inactivation.
Apolipoprotein E enhances uptake of soluble but not aggregated amyloid‐β protein into synaptic terminals
Authors: Gylys Karen H. , Fein Jeffrey A. , Tan Aiko M. , Cole Gregory M.
Published: March 2003

The cellular mechanism by which apolipoprotein E (apoE) affects the pathogenesis of Alzheimer's disease (AD) is not understood. We have examined the effect of apolipoprotein E on the internalization of exogenous amyloid‐β 1–40 (Aβ40) into a rat brain crude synaptosomal preparation. Aβ40 peptide in soluble (within 1 h of dilution in buffer) or aggregated (aged 4 days before dilution in buffer) form was pre‐incubated with lipidated apoE then added to synaptosomes; intraterminal amyloid‐β labeling was quantified using flow cytometry following immunolabeling with the anti‐Aβ (10G4) antibody. The number of Aβ‐positive synaptosomes was increased (∼50%) by treatment with a soluble Aβ/apoE mixture compared with treatment with soluble Aβ40 alone. However, when the Aβ was aggregated, less sodium dodecyl sulfate (SDS)‐stable Aβ/apoE complex was formed and the addition of apoE decreased the number of Aβ‐positive terminals. The addition of the lipoprotein‐receptor related protein (LRP) antagonist receptor‐associated protein (RAP) inhibited the apoE‐induced increase in synaptosomal Aβ, and controls treated with trypsin and heparinase confirm intraterminal localization of the majority of the soluble Aβ. The apoE‐mediated increase in Aβ labeling was confirmed in intact cells by immunocytochemistry of dorsal root ganglion (DRG) neurons. These results suggest that complex formation with apoE enhances internalization of soluble Aβ uptake into terminals.
Caring dynamics as perceived by staff supporting daily occupations for developmentally disabled adults
Authors: Dychawy‐Rosner Irena , Eklund Mona , Isacsson Åke
Published: March 2003

Caring dynamics as perceived by staff supporting daily occupations for developmentally disabled adults

This study addresses caring staff experiences of hindrances and help in the support of daily occupations among people with developmental disabilities. Data were collected by means of a questionnaire consisting of open‐ended questions about the staff perceptions of their work experiences. The respondents (n=81), corresponding to 94.1% of all care staff employed in a geographically defined care area in southern Sweden, worked in various day activity units supporting the daily occupations of their clients. A constant comparative method of data analysis was used. Staff expressions were classified in two main categories of caring dynamics: an operational level and a managerial level. Four areas were identified at the operational level: encountering realities of practice, attitudes to the clients and work demand, using the potential of knowledge and strategies and applying helping actions to the client. The managerial level included two areas, generalized work strategy and individualized work strategy. It is suggested that to develop the quality of interventions for supporting daily activities among persons with developmental disabilities, efforts should be made to identify caring dynamics as experienced by the caring staff.
Physical and psychological health and social relations in patients with prolonged musculoskeletal disorders
Authors: Malmgren‐Olsson Eva‐Britt , Armelius Bengt‐Åke
Published: March 2003

Physical and psychological health and social relations in patients with prolonged musculoskeletal disorders

The purpose of this study was to describe and analyse the relationship between physical and psychological health and social relations in patients with prolonged musculoskeletal disorders in primary care. Seventy‐eight patients –64 women and 14 men – were included in the study. Data from a semi‐structured interview called addiction severity index (ASI), frequently used in psychiatric and drug abuse research and a visual analogue scale (VAS) symptom list as well were analysed using principal component analysis (PCA). The analysis gave a two‐dimensional model with four poles of related variables characterizing the whole group. The first dimension consisted of one pole characterized by present psychiatric symptoms and many somatic symptoms. The second pole on this dimension was characterized by well‐being, having work and feeling satisfaction with life. One pole on the second dimension was characterized by severe physical problems, related to sick leave and disability pension. The opposite pole on this dimension was characterized by severe psychiatric symptoms earlier in life and present relationship problems with family and other people. The ASI‐instrument was considered to be relevant for describing important problem areas in patients with prolonged musculoskeletal disorders.
Self‐reported sleep quality, strain and health in relation to perceived working conditions in females
Authors: Edéll‐Gustafsson Ulla M. , Kritz Eivor I. K. , Bogren I. Kristina
Published: March 2003

Self‐reported sleep quality, strain and health in relation to perceived working conditions in females

The aims of this study were to examine self‐reported sleep quality, perceived strain and health in relation to working conditions; the prevalence and severity of sleep disturbances and daytime distress arising from poor sleep in women on different work shifts. Furthermore, to see whether females with gastrointestinal symptoms, joint‐, back‐ or muscle‐pain and who are dissatisfied with working hours differ with regard to the above aspects. Finally, degree of strain‐related symptoms and sleep difficulties were tested as predictors of sleep quality and general health outcome. Important research questions are whether registered nurses and those on rotating work shifts have greater sleep problems than others. A total of 156 females, aged 20–59 years, working at three different casualty departments, answered structured questionnaires. The results showed a persistently high rate of psycho‐physiological long‐term effects of stress related to working conditions.

Thirty‐four per cent were dissatisfied with their working hours, and exhibited significantly more mental strain, fatigue/excessive tiredness and inability to relax after work because of involuntary thoughts, in relation to working conditions than others did.

Sixty‐two females (39.7%) complained of insufficient sleep. The sleep quality outcome was significantly predicted by difficulty falling asleep (odds ratio 8.4), difficulty in falling asleep after nocturnal awakening (odds ratio 3.4) and perceived exhaustion (odds ratio 2.6). Females suffering from gastrointestinal symptoms and joint‐, back‐ and muscle symptoms for several days in a week or even everyday were especially sensitive to worse sleep quality. Independent of work shifts, registered nurses exhibited a higher degree of mental strain and prolonged recovery in comparison with others. In conclusions, sleep initiation difficulties, troubled sleep and exhaustion significantly predicted reduced sleep quality outcome with decreased resilience to stress and vulnerability to psycho‐physiological disorders in females working within the health care system.
Measuring the experiences of health care for patients with musculoskeletal disorders (MSD): development of the Picker MSD questionnaire
Authors: Jenkinson Crispin , Coulter Angela , Gyll Robert , Lindström Pål , Avner Linda , Höglund Elisabeth
Published: March 2003

Measuring the experiences of health care for patients with musculoskeletal disorders (MSD): development of the Picker MSD questionnaire

Analysis of data from a survey of patients with musculoskeletal problems (mainly back and neck pain) to develop a core measure of patients' experiences of health care. A secondary purpose was to determine whether a single summary index figure could be generated from the instrument. The data reported here comes from a postal survey of patients attending a spine clinic in Stockholm, Sweden. After attending the clinic patients were mailed a questionnaire. Up to two reminders were sent to nonresponders. Questionnaires were sent to 342 patients. Totally 173 (51%) questionnaires were returned, of which 38.1% respondents were male and 61.2% female. The mean age of patients was 54 years (SD 13.84), ranging from 16 to 88. Sixteen items on the questionnaire were found to constitute a reliable index of patient experience and which seem to be tapping the most important aspects of patient experience. The index score was found to have high construct validity. The instrument provides a core set of issues that should be covered when assessing the quality of care patients attending clinics for musculoskeletal disorders.
Significant others' experience of suffering when living with women with breast cancer
Authors: Lindholm Lisbet , Rehnsfeldt Arne , Arman Maria , Hamrin Elisabeth
Published: March 2003

Significant others' experience of suffering when living with women with breast cancer

This is an inquiry into how significant others experience being close to a woman suffering from breast cancer. In order to find this out, theme interviews were arranged with 17 women and 16 significant others from four different caring cultures in Sweden and Finland. A phenomenological case study methodology was adopted and in the analysis of the data a scientific teamwork model was employed, based on ideas developed at the Vancouver School of Doing Phenomenology. The findings show that the significant others experience deep often unrelieved suffering. They consider themselves prisoners of a situation of uncertainty and powerlessness when standing by the woman. They are torn between their own suffering and their desire to alleviate the woman's suffering. A vicious circle of mutual protection intensifies the suffering of the significant other, while actively sharing the suffering brings relief. The gravity of the situation creates an ethical urge in the significant other to assume responsibility for life in common with the woman.
Microsatellite markers for the fungal banana pathogen Mycosphaerella musicola
Authors: Molina C. , Kaemmer D. , Aponte S. , Weising K. , Kahl G.
Published: March 2003

Yellow Sigatoka caused by the ascomycete Mycosphaerella musicola Leach, is one of the most severe banana diseases worldwide, which spread in most banana growing areas, until Black Sigatoka, a more aggressive disease caused by Mycosphaerella fijiensis, appeared. Because of the highly devastating nature of the latter pathogen, recent research almost exclusively focused on M. fijiensis. To close the gap of knowledge and to study the population structure of M. musicola in Yellow Sigatoka‐infested areas, we cloned and characterized a versatile set of 26 polymorphic locus‐specific microsatellite markers.
Isolation and characterization of microsatellite loci in the southern brown bandicoot (Isoodon obesulus), and their applicability to other marsupial species
Authors: Zenger K. R. , Johnston P. G.
Published: March 2003

The southern brown bandicoot (Isoodon obesulus) was once widely distributed throughout coastal regions of Australia, however, populations have now become fragmented and the number of individuals are declining rapidly. As a result, this species is now classified as endangered in New South Wales and requires management. We have developed eight microsatellite markers to investigate levels of genetic variation and subdivision among these isolated populations. These microsatellite markers show levels of variability ranging from four to eight alleles and observed heterozygosities of 0.353–0.938. These microsatellite markers are also suitable for similar population studies on other related marsupials.
Microsatellite loci from the house wren (Troglodytes aedon)
Authors: Cabe Paul R. , Marshall Kriste E.
Published: March 2003

We cloned seven microsatellite loci from house wrens (Troglodytes aedon) using a biotin enrichment protocol. Starting with fragments generated using DOP–PCR, fragments containing microsatellite motifs AC and AAC were captured using biotinylated probes and streptavidin coated magnetic particles. Captured fragments were cloned into plasmids; prior to sequencing, the plasmids were screened for microsatellites using a simple PCR approach. Five of the loci showed variation in a sample of nine individuals.
Development of microsatellite markers in polyploid Salix reinii
Authors: Lian C. , Nara K. , Nakaya H. , Zhou Z. , Wu B. , Miyashita N. , Hogetsu T.
Published: March 2003

Salix reinii Franch. et Savat., a crawl shrub, is one of the most dominant pioneer trees on the southeastern slope of Mt. Fuji, on which an early stage of the volcanic desert succession has been underway since the last eruption in 1707. To investigate the population genetic structure within and among patches of S. reinii, seven polymorphic microsatellite markers were developed by an enrichment procedure. The multiple banding patterns amplified by developed microsatellite markers showed the polyploidy in S. reinii growing on the southeastern slope of Mt. Fuji.
Characterization of microsatellite loci for the Argentine ant, Linepithema humile, and their potential for analysis of colony structure in invading Hawaiian populations
Authors: Ingram Krista K. , Palumbi Stephen R.
Published: March 2003

We developed primers for five polymorphic microsatellite loci to analyse the genetic structure of colonies in an invading Argentine ant population located in Haleakala National Park on the island of Maui, Hawaii. Microsatellite loci were isolated using both a polymerase chain reaction‐based and a cloning‐based method. With a range of 3–18 alleles and expected levels of heterozygosity of 0.46–0.77, these loci provide useful markers for the detection of colony and population structure in new or expanding populations of this species.
Characterization of microsatellite loci in the aphid species Metopeurum fuscoviride (Homoptera, Aphididae)
Authors: Massonnet Blandine , Leterme Nathalie , Simon Jean‐Christophe , Weisser Wolfgang W.
Published: March 2003

Small distance movements are of great importance for the dynamics of local populations of insects and can indirectly be assessed using molecular markers. We isolated six polymorphic microsatellite loci in the aphid species Metopeurum fuscoviride Stroyan, monophagous on the common Tansy (Tanacetum vulgare L.). Twenty‐five to 30 aphids from seven populations were analysed. Between three and 17 alleles were found per locus and expected heterozygosities ranged from 0.14 to 0.79. In total, 114 multilocus genotypes were found in 192 parthenogenetic aphids analysed, indicating that the resolution will be high enough to study differentiation on a small spatial scale.
Characterization of seven microsatellite marker loci in a genus of Malagasy lemurs (Propithecus)
Authors: Mayor M. I. , Sommer J. A. , Huebinger R. M. , Barber R. C. , Louis E. E.
Published: March 2003

The sifakas (genus Propithecus) are large, diurnal, lemurs endemic to the island of Madagascar. Throughout the island, lemur species are particularly vulnerable to extinction due to relatively small geographical ranges (Martin 2000). Thus, understanding the taxonomy of these highly endangered primates is essential for taking appropriate conservation action. For this study we collected tissue samples from 68 wild sifakas representing various Propithecus species. Genomic DNA was isolated and polymerase chain reaction (PCR) amplification was carried out. We describe seven microsatellites found to be polymorphic and useful for analysis of the population genetics of sifakas.
Isolation and characterization of microsatellite markers in the tropical tree species Dicorynia guianensis (Caesalpinaceae)
Authors: Latouche‐Hallé C. , Ramboer A. , Bandou E. , Caron H. , Decroocq S.
Published: March 2003

Dicorynia guianensis is a canopy tree endemic to French Guyana and the first to be exploited as timber wood. To investigate levels of diversity and dynamics of gene flow in a 40‐ha study plot, highly polymorphic microsatellite markers were developed. An enriched microsatellite library was constructed and seven microsatellite primer pairs were developed. Total genomic DNA was extracted and amplified from cambium tissue from 172 adult individuals. The level of genetic diversity was found to be low. A large heterozygote deficiency was found at one locus. This was resolved by redesigning the primer set.
New anonymous nuclear DNA markers for the pearl oyster Pinctada margaritifera and other Pinctada species
Authors: Arnaud‐Haond S. , Boudry P. , Saulnier D. , Seaman T. , Vonau V. , Bonhomme F. , Goyard E.
Published: March 2003

The black‐lipped oyster Pinctada margaritifera is highly exploited in French Polynesia where the pearl industry relies mostly on spat collection, and therefore on resources available in the wild. Little is known of these resources, and population genetic studies would be useful to improve management. We used two methods, direct amplification of length polymorphism (DALP) and exon primed intron crossing (EPIC) to develop five new nuclear markers presenting length polymorphism. Although these markers remained anonymous after using blast on GenBank, they are codominant and follow Hardy–Weinberg equilibrium. Tests on related species or subspecies of Pinctada gave encouraging results.
metasim 1.0: an individual‐based environment for simulating population genetics of complex population dynamics
Authors: Strand Allan E.
Published: March 2003

metasim provides a flexible environment in which to perform individual‐based population genetic simulations. A wide range of landscape‐level dynamics, population structures, and within‐population demographies can be represented using the framework implemented in this software. In addition, temporal variation in all demographic characteristics can be simulated, both deterministically and stochastically. Such simulations can be used to produce null distributions of genotypes under realistic conditions. These genotypic data can then be used by a variety of analytical programs to develop null expectations of any population genetic statistic estimated from genotypic data.
Characterization of polymorphic microsatellite loci in the red harvester ant, Pogonomyrmex barbatus
Authors: Volny Veronica P. , Gordon Deborah M.
Published: March 2003

The red harvester ant, Pogonomyrmex barbatus, is a monogynous, polyandrous species: each ant colony is founded by a single queen that has mated with one or more males. To study levels of polyandry within a colony, as well as relationships among colonies, we developed 10 polymorphic microsatellite loci for P. barbatus. With the number of alleles per locus ranging from 3 to 39, and expected heterozygosities of 0.58–0.95, these markers promise to be useful in the study of colony and population genetic structure.
Group‐specific polymerase chain reaction amplification of SSU rRNA‐encoding gene fragments from 12 microbial taxa
Authors: Van Borm Steven , Boomsma Jacobus J.
Published: March 2003

Starting from an alignment of all known representatives in GenBank, we designed group specific primers targeting SSU rRNA‐encoding sequences of 12 microbial taxa known to contain insect pathogens and symbionts. We tested the specificity of these primers using representative species of all 12 groups as control templates. Polymerase chain reaction amplification conditions were modified until only group‐specific templates yielded a positive signal. The presented primer pairs thus allow for the amplification of SSU rRNA‐encoding sequences representing specific microbial groups directly from the environment (a social insect host in our study). We discuss possible applications of the identified molecular tools.
identix, a software to test for relatedness in a population using permutation methods
Authors: Belkhir Khalid , Castric Vincent , Bonhomme François
Published: March 2003

The computer program identix estimates relatedness in natural populations using multilocus genotypic data. Queller & Goodnight's (1989) and Lynch & Ritland's (1999) estimators of pairwise relatedness are implemented, as well as the identity index of Mathieu et al. (1990). Estimates of the confidence intervals around these pairwise values are also provided. The null hypothesis of no relatedness (multilocus genotypes are independent draws from a panmictic population) is tested using a permutation method that compares the observed distribution of the moments of pairwise relatedness coefficients to that expected in unstructured population.
Characterization of polymorphic microsatellite markers in the adder, Vipera berus
Authors: Carlsson M. , Isaksson M. , Höggren M. , Tegelström H.
Published: March 2003

Microsatellite DNA markers can yield sufficient resolution for individual identification as well as provide genetic information on a larger, interpopulational scale. Here we present details on six microsatellite primer pairs developed for the adder, Vipera berus. The number of alleles found varied between 2 and 38 per locus. The objectives behind developing these markers included assessment both of paternity and population histories from different parts of the species’ range. Cross‐species amplification indicated that these markers may also be useful for studies of other species within the Viperidae family.
Microsatellite loci in the cactophilic species Drosophila antonietae (Diptera; Drosophilidae)
Authors: Machado L. P. B. , Manfrin M. H. , Silva‐Junior W. A. , Sene F. M.
Published: March 2003

Morphometric and isoenzymatic data have showed little variation among Drosophila antonietae populations. This suggests historic gene flow, due to the distribution of these populations, which are associated with cacti along rivers, and natural selection on these markers. Microsatellite loci have high variability and are ideal for detecting gene flow and analysing population structure. Here we describe the isolation of seven polymorphic microsatellite loci in D. antonietae.
Polymorphic microsatellites isolated from the cave fish Astyanax fasciatus
Authors: Strecker U.
Published: March 2003

Six polymorphic microsatellite loci from a library of the tetra Astyanax fasciatus from Mexico were isolated. Amplification and heterozygosity were tested in four cave and four surface populations. These loci were developed for population genetic study to detect gene flow between cave and surface populations.