bluuebunny/crossref_metadata_2025 huggingface dataset:
Altered processing of the neurotensin/neuromedin N precursor in PC2 knock down mice: a biochemical and immunohistochemical study
Authors: Villeneuve Pierre , Feliciangeli Sylvain , Croissandeau Gilles , Seidah Nabil G. , Mbikay Majambu , Kitabgi Patrick , Beaudet Alain
Published: March 2003

Neurotensin (NT) and neuromedin N (NN) are generated by endoproteolytic cleavage of a common precursor molecule, pro‐NT/NN. To gain insight into the role of prohormone convertases PC1, PC2, and PC7 in this process, we investigated the maturation of pro‐NT/NN in the brain of PC7 (PC7−/–), PC2 (PC2–/–), and/or PC1 (PC1+/– and PC2–/–; PC1+/–) knock down mice. Inactivation of the PC7 gene was without effect, suggesting that this convertase is not involved in the processing of pro‐NT/NN. By contrast, there was a 15% decrease in NT and a 50% decrease in NN levels, as measured by radioimmunoassay, in whole brain extracts from PC2 null as compared with wild type mice. Using immunohistochemistry, we found that this decrease in pro‐NT/NN maturation products was uneven and that it was most pronounced in the medial preoptic area, lateral hypothalamus, and paraventricular hypothalamic nuclei. These results suggest that PC2 plays a critical role in the processing of pro‐NT/NN in mouse brain and that its deficiency may be compensated to a regionally variable extent by other convertases. Previous data have suggested that PC1 might be subserving this role. However, there was no change in the maturation of pro‐NT/NN in the brain of mice in which the PC1 gene had been partially inactivated, implying that complete PC1 knock down may be required for loss of function.
Alternative splicing of the 5′‐sequences of the mouse EAAT2 glutamate transporter and expression in a transgenic model for amyotrophic lateral sclerosis
Authors: Münch C. , Ebstein M. , Seefried U. , Zhu B. , Stamm S. , Landwehrmeyer G. B. , Ludolph A. C. , Schwalenstöcker B. , Meyer T.
Published: March 2003

Glutamate‐mediated neurotoxicity and a reduced expression of the excitatory amino acid transporter 2 (EAAT2) have been described in the pathogenesis of several acute and chronic neurological conditions. EAAT2 is the major carrier of glutamate in the mammalian brain. However, the principles of EAAT2 expression regulation are not fully understood. For the human brain, extensive alternative splicing of the EAAT2 RNA has been shown. To delineate the complex RNA regulation of EAAT2 we investigated whether the murine species is a suitable model for the study of EAAT2 splicing events. We identified five splice variants (mEAAT2/5UT1–5) encoding different 5′‐untranslated sequences and two distinct N‐termini of the putative EAAT2 polypeptide. In the murine CNS we found a region‐specific expression pattern of the novel 5′‐variants of EAAT2 as shown by in situ hybridization, dot blotting and competitive reverse transcription polymerase chain reaction. Furthermore, we performed an expression analysis of the EAAT2 splice variants in the spinal cord of a transgenic model (SOD1G93A) of amyotrophic lateral sclerosis, a motor neurone disease for which altered splicing of EAAT2 has been discussed. We found an increased expression of mEAAT2/5UT4 and a reduction of mEAAT2/5UT5 in the early course of the disease. We conclude that alternative splicing of 5′‐sequences may contribute to the regional expression of the EAAT2 RNA and was altered in the pre‐symptomatic stage of the SOD1G93A‐mouse model for amyotrophic lateral sclerosis.
N‐Methyl‐d‐aspartate receptor subtype‐selectivity of homoquinolinate: an electrophysiological and radioligand binding study using both native and recombinant receptors
Authors: Grimwood, Sarah , Wafford Keith A. , Macaulay Alison , Hutson Pete H.
Published: March 2003

Homoquinolinate, a derivative of the endogenous NMDA agonist, quinolinate, has been shown to display higher affinity for Xenopus oocytes expressing NR2A‐ and NR2B‐containing receptors, compared to NR2C‐ and NR2D‐containing receptors, whilst autoradiographical experiments subsequently showed that [3H]homoquinolinate labelled a subpopulation of NMDA receptors in rat brain sections, with a similar distribution to NR2B‐containing receptors. In this study, we have shown that NMDA‐specific [3H]homoquinolinate binding to rat brain membranes comprised 44% of total binding with a Bmax value of 5.73 pmol/mg protein, which was inhibited by NMDA with Ki=0.867 µm. However, NMDA‐specific [3H]homoquinolinate binding was not observed for a number of human recombinant NMDA receptors investigated, suggesting that there are subtle differences between the binding sites of recombinant and native receptors. Electrophysiological experiments revealed that homoquinolinate activated human recombinant NR1a/NR2A, NR1a/NR2B and NR1a/NR2A/NR2B receptors with EC50 values of 25.2, 13.8 and 9.04 µm, respectively, with intrinsic activities of 148, 93.3 and 125%, respectively, compared to glutamate (=100%). In contrast to an autoradiographical study, these radioligand binding and electrophysiological experiments suggest that homoquinolinate is not highly selective for NR2B‐containing receptors.
Developmental alteration of nerve injury induced glial cell line‐derived neurotrophic factor (GDNF) receptor expression is crucial for the determination of injured motoneuron fate
Authors: Honma Masaru , Namikawa, Kazuhiko , Mansur, Khalil , Iwata, Tatsuya , Mori, Nozomu , Iizuka Hajime , Kiyama Hiroshi
Published: March 2003

Axotomy‐induced neuronal death occurs in neonatal motoneurons, but not in adult rat. Here we demonstrated that during the course of postnatal development, nerve injury induced down‐regulation of the glial cell line‐derived neurotrophic factor (GDNF) receptor GFRα1 in axotomized hypoglossal motoneurons of rat are gradually converted to the adult up‐regulation pattern of response. The compensatory expression of GFRα1 specifically in the injured motoneurons of neonates by adenovirus succeeded in rescuing the injured neurons without an application of growth factors. To the contrary, the nuclear antisense RNA for GFRα1 expression accelerates the axotomy‐induced neuronal death in pups. These findings suggest that the receptor expression response after nerve injury is critical for the determination of injured motoneuron fate.
Glial cell line‐derived neurotrophic factor up‐regulates GTP‐cyclohydrolase I activity and tetrahydrobiopterin levels in primary dopaminergic neurones
Authors: Bauer M. , Suppmann S. , Meyer M. , Hesslinger C. , Gasser T. , Widmer H. R. , Ueffing M.
Published: March 2003

Glial cell line‐derived neurotrophic factor (GDNF) protects dopaminergic neurones against toxic and physical damage. In addition, GDNF promotes differentiation and structural integrity of dopaminergic neurones. Here we show that GDNF can support the function of primary dopaminergic neurones by triggering activation of GTP‐cyclohydrolase I (GTPCH I), a key enzyme in catecholamine biosynthesis. GDNF stimulation of primary dopaminergic neurones expressing both tyrosine 3‐monooxygenase and GTPCH I resulted in a dose‐dependent doubling of GTPCH I activity, and a concomitant increase in tetrahydrobiopterin levels whereas tyrosine 3‐monooxygenase activity was not altered. Actinomycin D, asan inhibitor of de novo biosynthesis, abolished any GDNF‐mediated up‐regulation of GTPCH I activity. However, GTPCH I mRNA levels in primary dopaminergic neurones were not altered by GDNF treatment, suggesting that the mode of action for that up‐regulation is not directly connected to the regulation of GTPCH I transcription. We conclude that GDNF, in addition to its action in structural differentiation, also promotes differentiation regarding expression and enzymatic activity of a crucial component in the dopaminergic biosynthetic pathway.
Expression of mRNAs of multidrug resistance proteins (Mrps) in cultured rat astrocytes, oligodendrocytes, microglial cells and neurones
Authors: Hirrlinger Johannes , König Jörg , Dringen Ralf
Published: March 2003

Multidrug resistance proteins (Mrps) are ATP‐driven export pumps that mediate the export of organic anions from cells. So far only little information is available on expression and physiological functions of Mrps in brain. The expression of mRNAs of six Mrp paralogs in rat brain, as well as in rat cultures enriched for neurones, astrocytes, oligodendrocytes and microglial cells, was studied by qualitative and semiquantitative RT‐PCR analysis. In adult rat brain as well as in neural cell cultures the mRNAs coding for Mrp1, Mrp3, Mrp4 and Mrp5 were detected. Semiquantitative analysis revealed that the mRNAs coding for Mrp1 and Mrp5 were more abundant in the four cell culture types than mRNAs of the other Mrps. mRNAs coding for Mrp3 and Mrp4 were found at significant levels in cultured astrocytes and microglial cells, whereas cultures of neurones and oligodendrocytes contained only marginal quantities of these mRNAs. Putative physiological functions of Mrps in brain cells are discussed.
The production of hydrogen sulfide is regulated by testosterone and S‐adenosyl‐l‐methionine in mouse brain
Authors: Eto Ko , Kimura Hideo
Published: March 2003

Hydrogen sulfide (H2S) is endogenously produced in the brain from l‐cysteine by the enzyme cystathionine β‐synthase (CBS) and functions as a neuromodulator in the brain. H2S selectively enhances NMDA receptor‐mediated responses and alters hippocampal long‐term potentiation (LTP). The production of H2S is regulated by Ca2+/calmodulin‐mediated pathways and is enhanced in response to neuronal excitation. In addition to this fast regulation, we describe here a slower form of the regulation of H2S production by testosterone and S‐adenosyl‐l‐methionine (SAM), a CBS activator. Endogenous H2S in the mouse brain increases after birth, reaches a maximum level at 8 weeks and then decreases. Female brain contains less H2S than male brain at each age. A single administration of testosterone to female mice increases the endogenous H2S and SAM, which reach levels similar to those of male mice. In contrast, castration of male mice decreases the levels of testosterone, SAM and H2S in the brain. Administration of SAM once a day for 3 days increases the brain H2S without significantly changing the testosterone level. These observations suggest that testosterone can regulate the brain H2S level via changing the level of SAM.
Specific diadenosine pentaphosphate receptor coupled to extracellular regulated kinases in cerebellar astrocytes
Authors: Jiménez Ana I. , Castro Enrique , Delicado Esmerilda G. , Miras‐Portugal M. Teresa
Published: March 2003

In this study, we show specific intracellular responses evoked by the stimulation of astrocytes with the P1,P5‐di(adenosine‐5′)pentaphosphate, Ap5A. The stimulation of astrocytes with micromolar concentrations of the dinucleotide elicited rapid increases in intracellular calcium concentration ([Ca2+]i), showing an EC50 value of 15.27 ± 0.61 µm. Moreover, the stimulation of cells with nanomolar concentrations of Ap5A, unable to induce calcium responses, increased the phosphorylated forms of extracellular‐signal regulated kinase 1/2 (ERK) with an EC50 value of 9.8 ± 2.4 nm. The maximal activation was observed at 100 nm Ap5A, which was similar to that produced by epidermal growth factor (EGF) under the same experimental conditions. The present data reported here indicate that Ap5A mediated these effects by interacting with a specific receptor, not yet identified, which was different from the P2Y1 and P2Y2/P2Y4 receptors present in all individual astrocytes.
Bovine serum albumin enhances nicotinic acetylcholine receptor function in mouse thalamic synaptosomes
Authors: Butt Christopher M. , Hutton Scott R. , Marks Michael J. , Collins Allan C.
Published: March 2003

Bovine serum albumin (BSA) enhances nicotinic agonist‐induced 86Rb+ efflux from synaptosomal fractions of the mouse thalamus, but how it does so is not understood. The experiments reported here indicated that BSA enhancement of nicotinic acetylcholine receptor function was rapid, reversible, depended on BSA concentration, and occurred at all points of the nicotinic agonist concentration‐response curve. We hypothesized that BSA‐extractable compounds, such as long‐chain fatty acids, were responsible for inhibiting nicotinic responses in the absence of BSA. The hypothesis was tested by applying arachidonic, linolenic, or oleic acids in the absence of BSA after an initial prewash with BSA. All three fatty acids exhibited a rapid, concentration‐dependent inhibition of nicotinic‐agonist stimulated ion flux. Concentration‐response curves produced after 30 s of pre‐treatment with arachidonic acid were similar to those seen when BSA was completely absent. The effects of pre‐treatment were reversed immediately by the introduction of BSA. Furthermore, no effects of fatty acids were observed when preparations were continuously exposed to BSA or when BSA was continuously absent. These results suggest that the removal of endogenous, inhibitory compounds is largely responsible for the rapid, potentiating action of BSA at nicotinic acetylcholine receptors expressed in the mouse thalamus.
Brevican isoforms associate with neural membranes
Authors: Seidenbecher Constanze I. , Smalla Karl‐Heinz , Fischer Nora , Gundelfinger Eckart D. , Kreutz Michael R.
Published: March 2003

Brevican is a neural‐specific proteoglycan of the brain extracellular matrix, which is particularly abundant in the terminally differentiated CNS. It is expressed by neuronal and glial cells, and as a component of the perineuronal nets it decorates the surface of large neuronal somata and primary dendrites. One brevican isoform harbors a glycosylphosphatidylinositol anchor attachment site and, as shown by ethanolamine incorporation studies, is indeed glypiated in stably transfected HEK293 cells as well as in oligodendrocyte precursor Oli‐neu cells. The major isoform is secreted into the extracellular space, although a significant amount appears to be tightly attached to the cell membrane, as it floats up in sucrose gradients. Flotation is sensitive to detergent treatment. Brevican is most prominent in the microsomal, light membrane and synaptosomal fractions of rat brain membrane preparations. The association with the particulate fraction is in part sensitive to chondroitinase ABC and phosphatidylinositol‐specific phospholipase C treatment. Furthermore, brevican staining on the surface of hippocampal neurons in culture is diminished after hyaluronidase or chondroitinase ABC treatment. Taken together, this could provide a mechanism by which perineuronal nets are anchored on neuronal surfaces.
Increased synthesis but decreased processing of neuronal proCCK in prohormone convertase 2 and 7B2 knockout animals
Authors: Rehfeld Jens F. , Lindberg Iris , Friis‐Hansen Lennart
Published: March 2003

In addition to its role as a gut hormone, cholecystokinin (CCK) is a widespread and potent neurotransmitter. Its biosynthesis requires endoproteolytic cleavage of proCCK at several mono‐ and dibasic sites by subtilisin‐like prohormone convertases (PCs). Of these, PC1 and PC2 are specific for neuroendocrine cells. We have now examined the role of PC2 and its binding protein, 7B2, in the neuronal processing of proCCK by measurement of precursor, processing‐intermediates and bioactive end‐products in brain extracts from PC2‐ and 7B2‐null mice and from corresponding controls. PC2‐null mice displayed a nine‐fold increase of cerebral proCCK concentrations, and a two‐fold increase in the concentrations of the processing‐intermediate, glycine‐extended CCK, whereas the concentrations of transmitter‐active (i.e. α‐amidated andO‐sulfated) CCK peptides were reduced (61%). Chromatography showed thatO‐sulfated CCK‐8 still is the predominant transmitter‐active CCK in PC2‐null brains, but that the fraction of intermediate‐sized CCK‐peptides (CCK‐58, ‐33 and ‐22) was eight‐fold increased. 7B2‐null brains displayed a similar pattern but with less pronounced precursor accumulation. In contrast with the cerebral changes, PC2 deficiency was without effect on proCCK synthesis and processing in intestinal endocrine cells, whereas 7B2 deficiency halved the concentration of bioactive CCK in the intestine. The results show that PC2 plays a major neuron‐specific role in the processing of proCCK.
Modulation of somatostatin receptors, somatostatin content and Gi proteins by substance P in the rat frontoparietal cortex and hippocampus
Authors: Puebla Lilian , Arilla‐Ferreiro Eduardo
Published: March 2003

Substance P (SP) and somatostatin (SRIF) are widely spread throughout the CNS where they play a role as neurotransmitters and/or neuromodulators. A colocalization of both neuropeptides has been demonstrated in several rat brain areas and SP receptors have been detected in rat cortical and hippocampal somatostatinergic cells. The present study was thus undertaken to determine whether SP could modulate SRIF signaling pathways in the rat frontoparietal cortex and hippocampus. A single intraperitoneal injection of SP (50, 250 or 500 µg/kg) induced an increase in the density of SRIF receptors in membranes from the rat frontoparietal cortex at 24 h of its administration, with no change in the hippocampus. The functionality of the SRIF receptors was next investigated. Western blot analysis of Gi proteins demonstrated a significant decrease in Giα1 levels in frontoparietal cortical membranes from rats treated acutely (24 h) with 250 µg/kg of SP, which correlated with a decrease in functional Gi activity, as assessed by use of the non‐hydrolyzable GTP analog 5′‐guanylylimidodiphosphate. SRIF‐mediated inhibition of basal or forskolin‐stimulated adenylyl cyclase activity was also significantly lower in the frontoparietal cortex of the SP‐treated group, with no alterations in the catalytic subunit of the enzyme. SRIF‐like immunoreactivity content was increased in the frontoparietal cortex after acute (24 h) SP administration (250 or 500 µg/kg) as well as in the hippocampus in response to 7 days of SP (250 µg/kg) administration. All these SP‐mediated effects were prevented by pretreatment with the NK1 receptor antagonist RP‐67580. Although the physiologic significance of these results are unknown, the increase in SRIF receptor density together with the desensitization of the SRIF inhibitory signaling pathway might be a mechanism to potentiate the stimulatory pathway of SRIF, inducing a preferential coupling of the receptors to PLC.
Palmitic and stearic fatty acids induce caspase‐dependent and ‐independent cell death in nerve growth factor differentiated PC12 cells
Authors: Ulloth Joel E. , Casiano Carlos A. , De Leon Marino
Published: March 2003

Apoptotic cell death has been proposed to play a role in the neuronal loss observed following traumatic injury in the CNS and PNS. The present study uses an in vitro tissue culture model to investigate whether free fatty acids (FFAs), at concentrations comparable to those found following traumatic brain injury, trigger cell death. Nerve growth factor (NGF)‐differentiated PC12 cells exposed to oleic and arachidonic acids (2 : 1 ratio FFA/BSA) showed normal cell survival. However, when cells were exposed to stearic and palmitic acids, there was a dramatic loss of cell viability after 24 h of treatment. The cell death induced by stearic acid and palmitic acid was apoptotic as assessed by morphological analysis, and activation of caspase‐8 and caspase‐3‐like activities. Western blotting showed that differentiated PC12 cells exposed to stearic and palmitic acids exhibited the signature apoptotic cleavage fragment of poly (ADP‐ribose) polymerase (PARP). Interestingly, blockade of caspase activities with the pan‐caspase inhibitor z‐VAD‐fmk failed to prevent the cell death observed induced by palmitic or stearic acid. RT‐PCR and RNA blot experiments showed an up‐regulation of the Fas receptor and ligand mRNA. These findings are consistent with our hypothesis that FFAs may play a role in the cell death associated with trauma in the CNS and PNS.
Glutamate levels and transport in cat (Felis catus) area 17 during cortical reorganization following binocular retinal lesions
Authors: Massie Ann , Cnops Lieselotte , Jacobs Sandy , Van Damme Katrien , Vandenbussche Erik , Eysel Ulf T. , Vandesande Frans , Arckens Lutgarde
Published: March 2003

Glutamate is known to play a crucial role in the topographic reorganization of visual cortex after the induction of binocular central retinal lesions. In this study we investigated the possible involvement of the glial high‐affinity Na+/K+‐dependent glutamate transporters in cortical plasticity using western blotting and intracortical microdialysis. Basal extracellular glutamate levels and the re‐uptake activity for glutamate have been determined by comparing the extracellular glutamate concentration before and during the blockage of glutamate removal from the synaptic cleft with the potent transporter inhibitor l‐trans‐pyrrolidine‐3,4‐dicarboxylic acid. In cats with central retinal lesions we observed increased basal extracellular glutamate concentrations together with a decreased re‐uptake activity in non‐deprived, peripheral area 17, compared with the sensory‐deprived, central cortex of the same animal as well as the topographically matching regions of area 17 in normal subjects. Western blotting experiments revealed a parallel decrease in the expression level of the glial glutamate transporter proteins GLT‐1 and GLAST in non‐deprived cortex compared with sensory‐deprived cortex of lesion cats and the corresponding regions of area 17 of normal subjects. This study shows that partial sensory deprivation of the visual cortex affects the removal of glutamate from the synaptic cleft and implicates a role for glial–neuronal interactions in adult brain plasticity.
Quality indicators in postoperative pain management: a validation study
Authors: Idvall Ewa , Hamrin Elisabeth , Sjöström Björn , Unosson Mitra
Published: March 2003

Quality indicators in postoperative pain management: a validation study

In a previous study, strategic and clinical quality indicators were developed from a tentative model to assess high quality in postoperative pain management. The aim of the present study was to investigate the content validity of these 15 indicators. The indicators were compiled in a questionnaire, and two groups of nurses (n=210, n=321) scored each indicator on a 5‐point scale (strongly disagree to strongly agree) from three different standpoints: whether it was essential for achieving high quality, whether it was realistic to carry out, and whether it was possible for nurses to influence management. The respondents were also asked to choose the most crucial indicators for the quality of care. The results showed that both groups of nurses judged the 15 indicators to have content validity from all three standpoints. Both groups also found the same six indicators to be the most crucial. These indicators concerned detecting and acting on signs and symptoms, performing prescriptions, informing and educating, acting on behalf of patients, competence/knowledge, and attitudes. The validated indicators should be useful to consider when implementing a strategy for postoperative pain management and when planning to evaluate the quality of care.
Health care professionals' understanding of chronic pain: a grounded theory study
Authors: Thunberg K.A , Carlsson S.G. , Hallberg L.R‐M.
Published: March 2003

The aim of this qualitative study was to explore the way heath care professional pereceive chronic pain. In‐depth interviews with 22 members of the staff at a Swedish hospital were analysed according to grounded theory methodology. Three descriptive categories were grounded in the data: ‘the professional's caring reality’, and ‘the professional's thoughts on ideal care’. These categories were then subsumed under a higher order category which we labelled as ‘professional ambiguity’. All the repondents gave evidence of having ideas about an ideal way of handling pain, largely feflecting a biopsycho‐social model. AT the same time, in their way of describing their everyday way of working with these problems, they expressed quite different, biomedical principles. The ambiguity from these contradictory representations is discussed in terms of organizational bases.
Orientation towards living in an old age home: an instrument to predict use of an old age home
Authors: Haken Liesbeth M. , Steverink Nardi , Van Den Heuvel Wim J. A. , Lindenberg Siegwart M.
Published: March 2003

Background:
 This study presents an alternative assessment method for establishing the demand for an old age home among a community‐dwelling older population. The instrument, called ‘orientation towards admission into an old age home’, represents the intensity of the need for admission as expressed by older people themselves. Therefore it is indicative of the ‘subjective demand’. Methods: Using a longitudinal design (1993–98), the study tests whether a stronger orientation towards admission into an old age home leads to use of an old age home. This assessment method is compared with another method of assessing ‘subjective demand’, that is by those who have applied for and are waiting for admission. Additionally, the method is compared with an ‘objective’ indicator of demand, that is, the level of physical impairments and age of the elderly person. Results: Results show that the subjective demand as measured by the ‘orientation toward admission into an old age home’ is indeed related to actual use of an old age home. The subjective demand as measured by being on a waiting list is not significantly related to the use of an old age home. The level of physical impairments (the objective demand) and age are sometimes, but not always, significantly related to the use of an old age home. Conclusion: The instrument ‘orientation’ provides us with a valuable instrument in assessing ‘subjective demand’ for an old age home among community‐dwelling older people.
Danish research‐active clinical nurses overcome barriers in research utilization
Authors: Adamsen Lis , Larsen Kristian , Bjerregaard Lene , Madsen Jan K.
Published: March 2003

Aim: The aim of this study was to examine whether there was a difference between clinical nurses who were research‐active, and clinical nurses who were nonresearch‐active in utilization of research. A further aim was to identify the most significant barriers faced by a group of Danish clinical nurses in their use of research.

Background: Discrepancy between the improved quality of research results and the lack of implementing them was the starting point for a series of studies which showed the types of barriers clinical nurses found especially cumbersome when applying the research results of other researchers. This study investigates whether the clinical nurses' own engagement in research had any impact on their perception of research utilization.

Methodology: The study had an exploratory and descriptive design. Seventy‐nine Danish clinical nurses participated and semi‐structured interviewing was used as the research method.

Findings: There was a statistically significant difference between the research‐active and nonresearch‐active nurses on various variables. The study showed that, to a larger extent, research‐active nurses used evidence‐based knowledge and were generally more internationally orientated. Furthermore, two important barriers for research utilization were identified by all 79 clinical nurses included in the study, i.e. 90% of the nurses explained that the quantity of research results was overwhelming, and 75% of them found that they were unable to evaluate the quality of the research.

Conclusions: Clinical nurses, who were research‐active themselves, experienced more success in overcoming some of the barriers, which existed in applying research to practice. The research potential found amongst clinical nurses in Denmark needed to be further supported through training and guidance in research methodology, establishing introductory stipends and part‐time research positions. By doing so, some of the barriers affecting research utilization and the so‐called theory–practice gap might be reduced. Further empirical studies, based on Giddens theory of sociological reflectivity, might see clinical nurses in a more serious light and simultaneously perceive them as producers of knowledge.
Characterization of 11 polymorphic tetranucleotide microsatellites for forensic applications in California elk (Cervus elaphus canadensis)
Authors: Jones Kenneth C. , Levine Kenneth F. , Banks James D.
Published: March 2003

Eleven polymorphic tetranucleotide microsatellite loci have been developed for forensic use in the protection of California elk. Based on a reference sample of elk taken from three races throughout California, the loci consist of 4–9 alleles (average 6.125). Probabilities of identity (Paetkau et al. 1995) range from 0.079 to 0.288, with an overall probability of identity of 1.3 × 10−9 (one in 7.8 × 108).
Microsatellite markers for the wasp Euodynerus foraminatus (Vespidae: Eumeninae)
Authors: Stahlhut Julie K. , Cowan David P. , Essani Karim , Shoemaker D. Dewayne , Barkman Todd J.
Published: March 2003

We have identified five polymorphic microsatellite loci for the solitary wasp Euodynerus foraminatus, using a partial genomic library constructed from random amplified polymorphic DNA fragments. We detected between three and 13 alleles per locus in a sample of 30 female wasps collected in southwest Michigan, USA. Observed heterozygosities ranged from 0.2 to 0.73. These markers will be used in our ongoing studies of sex determination and naturally occurring inbreeding in this species.
Microsatellite markers for northern red oak (Fagaceae:Quercus rubra)
Authors: Aldrich Preston R. , Michler Charles H. , Sun Weilin , Romero‐Severson Jeanne
Published: March 2003

We provide primer sequences for 14 (GA)nmicrosatellite loci developed from northern red oak, an important timber species. We screened loci using two sets of samples. A parent–offspring set included DNA from seven acorns collected from one mother tree along with maternal DNA, to determine that all progeny carried a maternal allele at each locus. The other set was comprised of 10 adult trees sampled from Indiana old‐growth forest, providing a measure of diversity revealed by each locus.
managedpop: a computer simulation to project allelic diversity in managed populations with overlapping generations
Authors: Birnbaum Kenneth , Benfey Philip N. , Peters Charles M. , Desalle Rob
Published: March 2003

We present a Monte Carlo simulation, managedpop, to project the loss of allelic diversity in a population with overlapping generations supported (or invaded) by a prodigious subpopulation. Input parameters allow the user to account for complex life histories and critical management practices, such as the frequency at which supportive breeding stocks are replaced. The simulation could also be used to examine the threat of species or population level extinction via hybridization. managedpop merges theoretical formulations on the effective size of supported populations and of populations with overlapping generations using easily measured life history traits.
Characterization of microsatellite DNA markers in the white‐bearded manakin (Manacus manacus)
Authors: Piertney Stuart B. , Shorey Lisa , Höglund Jacob
Published: March 2003

Eight microsatellite DNA markers were isolated and characterized from white bearded manakin (Manacus manacus) using an enrichment cloning procedure. A large number of alleles (range 9–25), and high levels of observed heterozygosity (mean 0.67) were resolved in 236 individuals. No evidence for linkage disequilibrium or the presence of null alleles was found, indicating that these markers will be useful for examining genetic relatedness, parentage and population structure in manakins.
Highly polymorphic microsatellite markers developed for the social halictine bee Lasioglossum (Chilalictus) hemichalceum
Authors: Kukuk P. F. , Forbes S. H. , Zahorchack R. , Riddle A. , Pilgrim K.
Published: March 2003

Lasioglossum
(
Chilalictus
)
hemichalceum is a social halictine bee species for which we developed 10 polymorphic microsatellite loci in order to investigate detailed genetic structure of cooperating indvididuals. The loci are highly polymorphic with allele numbers ranging between eight and 22. A null allele was detected at one locus in the absence of pedigree information.
Sequence characterized amplified polymorphic markers for the pitch canker pathogen, Fusarium circinatum
Authors: Britz H. , Wingfield B. D. , Coutinho T. A. , Wingfield M. J.
Published: March 2003

Fusarium circinatum
is the causal agent of pitch canker disease of pines. This pathogen is thought to have originated in Central America and currently poses a serious threat to commercial pine plantations in many areas of the world. In this study, polymorphic molecular markers were developed for
F. circinatum
using the internal short sequence repeats‐polymerase chain reaction (ISSR‐PCR) technique. Nine sequence characterized amplified polymorphic markers were developed. Thirty‐two putative alleles were observed among 103
F. circinatum
isolates from different geographical areas using the nine polymorphic markers. These sequence characterized amplified polymorphic markers can be used as genetic tools in populations studies of
F. circinatum.
Sequence variation of intergenic mitochondrial DNA spacers (mtDNA‐IGS) of Phytophthora infestans (Oomycetes) and related species
Authors: Wattier R. A. M. , Gathercole L. L. , Assinder S. J. , Gliddon C. J. , Deahl K. L. , Shaw D. S. , Mills D. I.
Published: March 2003

The potato late‐blight disease is caused by the pseudofungus Phytophthora infestans (Oomycetes). This pathogen was of historical importance as it caused the Irish Potato Famine. There is currently a worldwide resurgence of the disease. Following worldwide migrations as well as being able to discriminate P. infestans from related species are key issues. We present sequence variation of five inter‐genic mitochondrial DNA spacers (mtDNA‐IGS) for P. infestans and four related taxa. Intra and inter‐taxon variation was observed showing potential for both molecular ecology and molecular systematic.
How do I know it's health promotion? A study of health promotion activities and awareness in student placements
Authors: Schickler Pam , James Trudi , Smith Pam
Published: March 2003

Bridging the gap between the theory and practice of health promotion on student placements is a challenge. Recent policy documents and the National Occupational Standards for professional activity have highlighted the need to provide training for health professionals in this area. This paper draws on a study to investigate students’, lecturers’ and clinical staff's understanding of the practice of, and education for, health promotion, and their perception of how clinical competence is achieved in this domain. Questionnaire findings revealed that students and newly qualified staff displayed a narrow perception of health promotion, despite a wider definition that now pervades theoretical teaching. Students benefited from health promotion sessions in the university and used much of this information to promote their own and their family's health. The use of more open and qualitative techniques (focus groups and semi‐structured interviews) and prompting through amplification of the term health promotion induced students to realize that they were in fact practising a wider definition. Findings indicate that students would welcome the opportunity to extend their health promotion practice. Furthermore, the data suggested that articulation by clinicians of their health promotion practice, together with discussion and reflection, would help students and staff embed knowledge into practice. Visible parts of health promotion, such as advice on smoking cessation, were easier to articulate and put into practice than were the less tangible aspects, such as tackling inequalities. Lack of time and poor staffing levels constrained the ability of supervisors and students to discuss and reflect on health promotion theory and practice. However, opportunities, especially in the community, were more frequently pinpointed as learning experiences compared with the acute sector. Use of the National Occupational Standards was seen as a way to develop curricula, while active mentoring was identified as a means of evaluating and enhancing health promotion activities in the clinical learning environment.
The use of muscle protein for egg production in the Zebra FinchTaeniopygia guttata
Authors: Cottam Mat , Houston David , Lobley Gerald , Hamilton Ian
Published: March 2003

Pectoral muscle can be an important source of protein for birds. During egg formation Zebra FinchesTaeniopygia guttataare able to compensate for nutritional inadequacies in their diet by utilization of the protein in their flight muscles. This analysis of flight muscle sarcoplasm supported earlier observations of protein depletion during egg production. However, SDS gel electrophoresis of the sarcoplasm produced no evidence to support a previous suggestion of the existence of a high molecular weight storage protein, and it is thought that the original observation may have arisen as an artefact of experimental methodology. During laying, protein removal from the sarcoplasm occurred over a range of different proteins and was not confined to any one specific protein band. Additionally, the protein band most reduced over the course of laying did not contain elevated levels of the amino acids most limiting to egg production. These results indicate that during laying, flight muscle sarcoplasm contributes towards the nutrient requirements of egg production from general protein reserves, rather than from a specific storage protein containing elevated levels of limiting amino acids.
Geographical variation in egg size of the Great Tit Parus major: a new perspective
Authors: Encabo Silvio I. , Barba Emilio , Gil‐Delgado Jose A. , Monrós Juan S.
Published: March 2003

A recent study on geographical variation in egg size of Great Tits Parus major concluded that: (1) mean egg size tended to increase with increasing latitude; and (2) mean egg size was positively correlated with mean clutch size. Including new data on both egg and clutch size, we reanalysed the relationships between egg size, clutch size and latitude, and investigated the possible effects of habitat type, female body size and egg shape on these relationships. We found that (1) egg volume showed minimum values around 51°N, increasing both north and southwards; (2) female body size increased linearly with increasing latitude; (3) female body size was positively correlated with egg breadth, but not with egg length or egg volume; (4) the sphericity index of the eggs (breadth to length ratio) was largest at medium latitudes, and eggs were more elongated towards the north and the south; (5) the relationship between clutch size and latitude was curvilinear, with the largest clutch sizes at intermediate latitudes; (6) egg size was not correlated with clutch size when the complete latitudinal range was considered, but egg size was negatively correlated with clutch size between 40 and 51°N; and (7) egg size did not differ among habitat types. We suggest that female body size (which probably limits egg breadth), and the pressure for producing large eggs (which in turn increases the reproductive success) are the main determinants of geographical variation in egg size and shape. Populations of small‐bodied Great Tits seem to escape from the limits of their size, producing relatively elongated eggs, so that from a certain latitude southwards, egg volume does not decrease in spite of a decrease in female body size. Moreover, the negative relationship between egg and clutch size at low latitudes suggests that energetic trade‐offs may also contribute to determine egg size in the south.
Shifts in tonic accommodation after near work are related to refractive errors in children
Authors: Gwiazda Jane , Bauer Joseph , Thorn Frank , Held Richard
Published: March 2003

A link between changes in tonic accommodation (TA) produced by sustained near work and the development of adult‐onset myopia has been suggested in studies of young adults. Measures of TA before and after near work have been lacking in children of school age, which is the most susceptible period for the development and progression of juvenile‐onset myopia. In the present study accommodation was measured in 87 children, aged 7 to 16 years, before and after 15 minutes of video game playing. All children were refracted before testing and wore optical correction during measures of accommodation with a Canon R1 autorefractor. Most children showed initial values of TA (far focus minus dark focus) between 0.0 and 1.0D, with a mean of 0.68D. Grouped by refractive status, the myopic children initially showed 0.30D of TA, while the emmetropic children showed 0.75D and the hyperopic children showed 0.94D. After playing the video game, TA of the myopes increased by 1.15D, compared to smaller increases for the emmetropes (0.68D) and hyperopes (0.24D). Comparable values have been obtained from young adults. These results indicate that the smallest initial values of TA and the largest inward shifts in TA are found during the period of acquisition and progression of myopia, regardless of age.
A clinical trial of the SUN SK‐2000 computer‐assisted videokeratoscope
Authors: Dave Trusit N. , Fowler Colin W. , Elawad Mohammed E. A. , Dunne Mark C. M.
Published: March 2003

A clinical trial was performed on 20 optometry students in order to evaluate the suitability of the SUN SK‐2000 (SUN contact lens company, Japan) computer‐assisted videokeratoscope for use in clinical practice. Suitability was assessed by observing three factors: the accuracy, repeatability and agreement for central mean corneal power (MCP) with a keratometer (Javal Schiotz). Measurements of eight peripheral points and the central radius of curvature were made on 20 optometry students and on an 8mm calibration surface using the SUN SK‐2000. The SUN SK‐2000 accurately determined the 8mm calibration surface (supplied by manufacturers) to be spherical (SD = ±0.013, P = 0.776). Careful alignment was found to be an important factor in determining the actual radius of the calibration sphere. Unfortunately, the system required measurements to be taken at a point which was not coincident with the line of sight. A simple improvement to this has been suggested. Readings were most repeatable for central corneal radii. Peripheral radii showed the most repeatability for the horizontal and inferior corneal radii. It has been suggested that the ocular adnexa may be a possible cause for the poor repeatability in the superior area of the cornea. The level of agreement between the Javal Schiotz keratometer and the SUN SK‐2000 in terms of mean refractive error (MRE) was not found to be sufficient for the two instruments to be interchangeable (P = 0.011). TheCo and C45 components of corneal astigmatism were found to have little association with the keratometer.
Responses to colour of neurones in area 7a of the inferior parietal lobule of the rhesus monkey
Authors: Blum Baruch
Published: March 2003

A single‐unit study on area 7a of alert, fixating rhesus monkeys revealed responsiveness to primary colours comparable to white light responsiveness shown in other cells. Mostly decremented, some biphasic, and a small portion with incremented neuronal firing response were observed, following stimulation of cells by parafoveal receptive field, rectangular, approximately 20°× 20° red, green or blue‐violet light stimuli. The same cell showed no response to white light. Receptive fields of these colour‐sensitive cells, like those of white‐sensitive cells, were mostly contralateral, some ipsilateral and a few in both hemifields. Augmentation of responses following preconditioning electrical stimulation of lateroposteriorpulvinar targets was observed as with the white‐light sensitive cells. It is noteworthy that this monkey area 7a colour sensitivity is complementary to previously demonstrated white light sensitivity. The specific properties revealed by these cells suggest separate channels within area 7a for colour and for achromatic light, the colour sensitivity possibly relevant when chromaticity is of generalized import, and these may subserve the animal's orienting response to colour appearance in the near‐periphery visual field.
Specific reading difficulty or decompensated heterophoria?
Authors: Rundstrom M. M. , Eperjesi F.
Published: March 2003

This case report illustrates the importance of both an educational psychology and optometric assessment in the management of reading difficulties. Only after these have been concluded can the aetiology of the reading difficulty be determined and the correct course of treatment instigated.
Temporal evolution of the corneal curvature in contact lens wearers
Authors: Velasco J. , Bermudez F. J. , Jimenez del Barco L.
Published: March 2003

In the present work, we have measured the corneal radii in a group of 126 healthy subjects, studying the temporal evolution of these radii after adaptation to contact lenses of polyhydroxyethyl methacrylate with 55% hydration. We measured the horizontal and vertical radii before adaptation, as well as after 3, 6 and 9 months of wearing contact lenses. The decreases were not significant (P < 0.05) in the corneal radii of these subjects; maximum decreases were reached the day after wearing contact lenses, with subsequent recuperation, such that at 9 months the decreases, though persisting, were minimal.
Keratometric variation: the influence of a fluid layer
Authors: Cronje‐Dunn S. , Harris W. F.
Published: March 2003

Variation of keratometric measurements on an approximately spherical surface on a polymethyl methacrylate (PMMA) button is compared to keratometric variation on the PMMA button after the application of an artificial tear solution. The variation is shown by means of scatter plots in a three‐dimensional space, as well as quantitatively in the form of variance‐covariance matrices. The wet button showed variances a factor of more than 1000 times that of the dry button. This suggests that the precorneal tear film could be an important, often‐overlooked contributing factor to keratometric variation in the case of the eye.
Is there a significant relationship between interocular acuity difference and the magnitude of anisometropic ametropia?
Authors: Cleary M. , Thompson C. M. , Winn B.
Published: March 2003

Purpose: Previous research reveals no consensus on this question despite 30 years of effort. Earlier studies raise criticisms, particularly in terms of patient inclusion criteria and use of traditional acuity charts with non‐uniform increments. These issues have been addressed in this investigation.

Methods: The samples were new untreated referrals to a hospital orthoptic department who were screened to exclude strabismus and ocular pathology. Corrected acuities were measured using Glasgow Acuity Cards 8–12 weeks after prescribing spectacles (1% cyclopentolate HCL cycloplegic refraction‐‐full prescription) but prior to any occlusion therapy. The dioptric differences in both the spherical equivalent (SER) and vector components of the two eyes were computed and each was compared with the interocular log MAR difference.

Results: Linear regression analyses of the 96 subjects (mean age 5.6 ± 2.1 years) revealed a significant association between the degree of anisometropia and magnitude of log MAR acuity difference: r = 0.326, P = 0.0018 (SER); r = 0.354, P = 0.0004 (vector analysis). A similar relationship was found (r = 0.338, P = 0.005 (SER); r = 0.34, P = 0.005 (vector analysis) when 28 individuals with astigmatism of ≥2 DC were excluded.

Conclusions: Our data support a significant relationship between degree of anisometropia and interocular log MAR difference. The correlation is greater using vector analysis.