bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic transformation of barley (Hordeum vulgare L.) via infection of androgenetic pollen cultures with Agrobacterium tumefaciens
Authors: Kumlehn Jochen , Serazetdinova Liliya , Hensel Goetz , Becker Dirk , Loerz Horst 
Published: January 2006

SummaryA novel genetic transformation method for barley (Hordeum vulgare L.), based on infection of androgenetic pollen cultures with Agrobacterium tumefaciens, is presented. Winter‐type barley cv. ‘Igri’ was amenable to stable integration of transgenes mediated by A. tumefaciens strain LBA4404 harbouring a vector system that confers hypervirulence, or by the non‐hypervirulent strain GV3101 with a standard binary vector. The efficacy of gene transfer was substantially influenced by pollen pre‐culture time, choice of Agrobacterium strain and vector system, Agrobacterium population density, medium pH and the concentrations of acetosyringone, CaCl2 and glutamine. After co‐culture, rapid removal of viable agrobacteria was crucial for subsequent development of the pollen culture. To this end, the growth of agrobacteria was suppressed by the concerted effects of appropriate antibiotics, low pH, reduced level of glutamine and high concentrations of CaCl2 and acetosyringone. Following infection with LBA4404 and GV3101, about 31% and 69%, respectively, of the primary transgenic (T0) plants carried a single copy of the sequence integrated. The use of hypervirulent A. tumefaciens and hygromycin resistance as a selectable marker resulted in 3.7 T0 plants per donor spike. About 60% of the primary transgenic plants set seed, indicating spontaneous genome doubling. An analysis of 20 T1 populations revealed that four progenies did not segregate for reporter gene expression. This indicates that the approach pursued enables the generation of instantly homozygous primary transgenic plants. The method established will be a valuable tool in functional genomics as well as for the biotechnological improvement of barley.
HETEROGENEITY IN A CURRENCY UNION WITH SOCIAL MARKET OBJECTIVES
Authors: Hallett Andrew Hughes , Weymark Diana N. 
Published: January 2006

ABSTRACTIn this paper, we explore whether heterogeneity among union members could threaten the stability of the European Monetary Union. The types of heterogeneity we consider are (1) asymmetries in the transmission of monetary and fiscal policies, and (2) differences in national preferences for price stability, output growth, and income redistribution. Our results show that the costs of membership can be significant for countries whose transmissions, structure, or preferences deviate from those underlying the common monetary policy. In part, these costs arise because monetary policy imposed by an independent central bank automatically constrains the use of fiscal policy by national governments.
MONETARY–FISCAL INTERACTIONS WITH A CONSERVATIVE CENTRAL BANK
Authors: Lambertini Luisa 
Published: January 2006

ABSTRACTWe study macroeconomic stabilization when monetary and fiscal policies interact via their effects on output and inflation and the monetary authority is more conservative than the fiscal. We find that monetary–fiscal interactions result in poor macroeconomic stabilization. With both policies discretionary, the Nash equilibrium is suboptimal with higher output and lower inflation than optimal; the Nash equilibrium may be extreme with output higher and inflation lower than either authority want. Leadership equilibria are not second best. Monetary commitment is completely negated by fiscal discretion and yields the same outcome as discretionary monetary leadership for all realizations of shocks. But fiscal commitment is not similarly negated by monetary discretion. Optimal macroeconomic stabilization requires either commitment of both monetary and fiscal policies, or identical targets for both authorities – output socially optimal and inflation appropriately conservative – or complete separation of tasks.
Healing effect of ketanserin on chronic leg ulcers in patients with diabetes
Authors: Quatresooz P , Kharfi M , Paquet P , Vroome V , Cauwenbergh G , Piérard GE 
Published: January 2006

AbstractBackground  The treatment of chronic leg ulcers remains a stubborn problem in many patients. Topical 2% ketanserin ointment, a 5HT2‐serotoninergic blocking agent, has been reported to improve healing of decubitus, venous, diabetic and ischaemic ulcers.Method  The present double‐blind intra‐individual comparative study was performed in 12 women with diabetes presenting with at least two similar leg ulcers. In each subject, the two lesions were randomly assigned to be treated for 8 weeks by 2% ketanserin ointment or its unmedicated vehicle. Objective assessments of the dynamics of wound healing were performed using computerized morphometry. Evaluations were performed at 2‐week intervals for 8 weeks.Results  A significant decrease in relative wound area was observed on the ketanserin‐treated ulcers compared with the placebo group.Conclusion  Topical ketanserin is a valuable therapy for difficult‐to‐treat leg ulcers.
Limited regulation of somatodendritic dopamine release by voltage‐sensitive Ca2+channels contrasted with strong regulation of axonal dopamine release
Authors: Chen Billy T. , Moran Kimberly A. , Avshalumov Marat V. , Rice Margaret E. 
Published: January 2006

AbstractThe mechanism underlying somatodendritic release of dopamine (DA) appears to differ from that of axon‐terminal release. Specifically, somatodendritic DA release in the substantia nigra pars compacta (SNc) persists in low extracellular Ca2+concentrations that are insufficient to support axonal release in striatum, suggesting that limited Ca2+entry is necessary to trigger somatodendritic release. Here, we compared the role of voltage‐dependent Ca2+channels in mediating DA release in striatum versus SNc using specific blockers of N‐, P/Q‐, T‐, R‐ and L‐type Ca2+channels individually and in combination. Release of DA evoked by a single stimulus pulse in the dorsal striatum and SNc of guinea‐pig brain slices was monitored in real time using carbon‐fiber microelectrodes with fast‐scan cyclic voltammetry. Single‐pulse evoked DA release was shown to be independent of regulation by concurrently released glutamate or GABA acting at ionotropic receptors in both regions. Under these conditions, striatal DA release was completely prevented by an N‐type channel blocker, ω‐conotoxin GVIA (100 nm), and was decreased by 75% by the P/Q‐type channel blocker ω‐agatoxin IVA (200 nm). Blockade of T‐type channels with Ni2+(100 µm) or R‐type channels with SNX‐482 (100 nm) decreased axonal release in striatum by 25%, whereas inhibition of L‐type channels with nifedipine (20 µm) had no effect. By contrast, none of these Ca2+‐channel blockers altered the amplitude of somatodendritic DA release in the SNc. Even a cocktail of all blockers tested did not alter release‐signal amplitude in the SNc, although the duration of the release response was curtailed. The limited involvement of voltage‐dependent Ca2+channels in somatodendritic DA release provides further evidence that minimal Ca2+entry is required to trigger the release process, compared with that required for axon‐terminal release.
Neprilysin participates in skeletal muscle regeneration and is accumulated in abnormal muscle fibres of inclusion body myositis
Authors: Broccolini Aldobrando , Gidaro Teresa , Morosetti Roberta , Gliubizzi Carla , Servidei Tiziana , Pescatori Mario , Tonali Pietro A. , Ricci Enzo , Mirabella Massimiliano 
Published: January 2006

AbstractNeprilysin (NEP, EP24.11), a metallopeptidase originally shown to modulate signalling events by degrading small regulatory peptides, is also an amyloid‐β‐ (Aβ) degrading enzyme. We investigated a possible role of NEP in inclusion body myositis (IBM) and other acquired and hereditary muscle disorders and found that in all myopathies NEP expression was directly associated with the degree of muscle fibre regeneration. In IBM muscle, NEP protein was also strongly accumulated in Aβ‐bearing abnormal fibres. In vitro, during the experimental differentiation of myoblasts, NEP protein expression was regulated at the post‐transcriptional level with a rapid increase in the early stage of myoblast differentiation followed by a gradual reduction thereafter, coincident with the progression of the myogenic programme. Treatment of differentiating muscle cells with the NEP inhibitor dl‐3‐mercapto‐2‐benzylpropanoylglycine resulted in impaired differentiation that was mainly associated with an abnormal regulation of Akt activation. Therefore, NEP may play an important role during muscle cell differentiation, possibly through the regulation, either directly or indirectly, of the insulin‐like growth factor I‐driven myogenic programme. In IBM muscle increased NEP may be instrumental in (i) reducing the Aβ accumulation in vulnerable fibres and (ii) promoting a repair/regenerative attempt of muscle fibres possibly through the modulation of insulin‐like growth factor I‐dependent pathways.
Selective deficits in the expression of striatal‐enriched mRNAs in Huntington's disease
Authors: Desplats Paula A. , Kass Kristi E. , Gilmartin Tim , Stanwood Gregg D. , Woodward Elliott L. , Head Steven R. , Sutcliffe J. Gregor , Thomas Elizabeth A. 
Published: January 2006

AbstractWe have identified and cataloged 54 genes that exhibit predominant expression in the striatum. Our hypothesis is that such mRNA molecules are likely to encode proteins that are preferentially associated with particular physiological processes intrinsic to striatal neurons, and therefore might contribute to the regional specificity of neurodegeneration observed in striatal disorders such as Huntington's disease (HD). Expression of these genes was measured simultaneously in the striatum of HD R6/1 transgenic mice using Affymetrix oligonucleotide arrays. We found a decrease in expression of 81% of striatum‐enriched genes in HD transgenic mice. Changes in expression of genes associated with G‐protein signaling and calcium homeostasis were highlighted. The most striking decrement was observed for a newly identified subunit of the sodium channel, beta 4, with dramatic decreases in expression beginning at 8 weeks of age. A subset of striatal genes was tested by real‐time PCR in caudate samples from human HD patients. Similar alterations in expression were observed in human HD and the R6/1 model for the striatal genes tested. Expression of 15 of the striatum‐enriched genes was measured in 6‐hydroxydopamine‐lesioned rats to determine their dependence on dopamine innervation. No changes in expression were observed for any of these genes. These findings demonstrate that mutant huntingtin protein causes selective deficits in the expression of mRNAs responsible for striatum‐specific physiology and these may contribute to the regional specificity of degeneration observed in HD.
The 5‐HT1A receptor agonist 8‐OH‐DPAT prevents prefrontocortical glutamate and serotonin release in response to blockade of cortical NMDA receptors
Authors: Calcagno E. , Carli M. , Invernizzi R. W. 
Published: January 2006

AbstractWe studied the role of 5‐HT1A receptors in controlling the release of glutamate (GLU) in the medial prefrontal cortex (mPFC) of conscious rats with the in vivo microdialysis technique. The effect of the 5‐HT1A receptor agonist 8‐hydroxy‐2‐(di‐n‐propylamino)tetralin infused in the prefrontal cortex was examined under basal conditions and on the rise of extracellular GLU (+106%) induced by co‐infusion of the competitive N‐methyl‐d‐aspartate receptor antagonist 3‐[(R)‐2‐carboxypiperazin‐4yl]‐propyl‐1‐phosphonic acid (CPP). 8‐OH‐DPAT (0.3 and 3 μm) had no effect on basal extracellular GLU, but the higher concentration completely abolished the rise of extracellular GLU induced by CPP. CPP also increased extracellular serotonin (5‐HT) in the mPFC (+50%) and this effect was antagonized by 3 μm 8‐OH‐DPAT which, by itself, had no effect on basal 5‐HT release. The effects of 8‐OH‐DPAT on extracellular GLU and 5‐HT were reversed by the 5‐HT1A receptor antagonist WAY100 635 (100 μm), indicating a selective involvement of 5‐HT1A receptors. WAY100 635 had no effect by itself. These results show that the stimulation of cortical 5‐HT1A receptors prevents the CPP‐evoked rise of extracellular GLU and 5‐HT and suggest that these effects may contribute to the ability of intracortical 8‐OH‐DPAT to counteract cognitive deficits caused by the blockade of NMDA receptors.
Mouse tryptophan hydroxylase isoform 2 and the role of proline 447 in enzyme function
Authors: Sakowski Stacey A. , Geddes Timothy J. , Kuhn Donald M. 
Published: January 2006

AbstractTryptophan hydroxylase (TPH) is the rate‐limiting enzyme in the synthesis of the neurotransmitter serotonin (5‐HT). Once thought to be a single gene product, TPH is now known to exist in two isoforms. Isoform 1 (TPH1) is found in the pineal gland and gut, and isoform 2 (TPH2) is selectively expressed in brain. A single‐nucleotide polymorphism in TPH2 results in a proline‐to‐arginine mutation at residue 447 and substantially lowers catalytic activity. In view of the importance of TPH in determining brain 5‐HT function, we cloned TPH2 and produced the P447R mutant to assess the importance of this proline in enzyme function. Catalytically active TPH2 and the P447R mutant were expressed at the predicted subunit molecular mass of 56 kDa. The P447R mutant expressed less than 50% of the activity of TPH2. Mutation of this conserved proline in TPH1 (P403R) also resulted in an enzyme with significantly lower activity than the wild‐type enzyme. The P447R mutant had a Vmax 50% lower than that of TPH2. The P447R mutation did not alter the oligomeric assembly of the protein, nor change its responsiveness to cysteine modification. The P447R mutation did not alter enzyme substrate specificity or stability, but conferred slightly enhanced sensitivity to inhibition by dopamine and diminished sensitivity to iron in catalysis. The conserved proline in TPH (residue 447 in TPH2 and 403 in TPH1) plays an important role in enzyme function by regulating Vmax of the catalytic reaction.
Resting and arecoline‐stimulated brain metabolism and signaling involving arachidonic acid are altered in the cyclooxygenase‐2 knockout mouse
Authors: Basselin Mireille , Villacreses Nelly E. , Langenbach Robert , Ma Kaizong , Bell Jane M. , Rapoport Stanley I. 
Published: January 2006

AbstractStudies were performed to determine if cyclooxygenase (COX)‐2 regulates muscarinic receptor‐initiated signaling involving brain phospholipase A2(PLA2) activation and arachidonic acid (AA; 20 : 4n‐6) release. AA incorporation coefficients, k* (brain [1–14C]AA radioactivity/integrated plasma radioactivity), representing this signaling, were measured following the intravenous injection of [1–14C]AA using quantitative autoradiography, in each of 81 brain regions in unanesthetized COX‐2 knockout (COX‐2–/–) and wild‐type (COX‐2+/+) mice. Mice were administered arecoline (30 mg/kg i.p.), a non‐specific muscarinic receptor agonist, or saline i.p. (baseline control). At baseline, COX‐2–/–compared with COX‐2+/+mice had widespread and significant elevations of k*. Arecoline increased k* significantly in COX‐2+/+mice compared with saline controls in 72 of 81 brain regions, but had no significant effect on k* in any region in COX‐2–/–mice. These findings, when related to net incorporation rates of AA from brain into plasma, demonstrate enhanced baseline brain metabolic loss of AA in COX‐2–/–compared with COX‐2+/+mice, and an absence of a normal k* response to muscarinic receptor activation. This response likely reflects selective COX‐2‐mediated conversion of PLA2‐released AA to prostanoids.
Calpain is activated in degenerating photoreceptors in the rd1 mouse
Authors: Paquet‐Durand Francois , Azadi Seifollah , Hauck Stefanie M. , Ueffing Marius , van Veen Theo , Ekström Per 
Published: January 2006

AbstractThe retinal degeneration (rd)1 mouse displays an inherited retinal degeneration and therefore allows studies of the molecular mechanisms behind the blinding disease retinitis pigmentosa. Activation of the calcium‐dependent protease calpain has been suggested to play an important role in cell death in various tissues, but little is known about the expression and activity of calpain during inherited retinal degeneration. Using microarray techniques, transcript levels of cyclic AMP response element‐binding protein (CREB)‐1, calpastatin and of various calpain genes were analysed in the rd1 mouse compared with its wild‐type control. Expression of distinct calpain isoforms and calpastatin was investigated using immunofluorescence and immunoblotting. Gene transcription and protein expression levels were compared with calpain activity using an enzymatic assay that allowed monitoring of calpain activity at the cellular level. We found that CREB‐1 and calpastatin expression was reduced in rd1 retinas, whereas calpain activity was substantially increased in rd1 photoreceptors. Calpain activity peaked at postnatal day 13, together with rd1 photoreceptor cell death. Calpain‐specific inhibitors decreased calpain activity in situ. These results indicate that activation of calpains correlates with rd1 photoreceptor cell death, which raises the possibility of using calpain inhibitors to prevent or delay photoreceptor degeneration.
Glia re‐sealed particles freshly prepared from adult rat brain are competent for exocytotic release of glutamate
Authors: Stigliani Sara , Zappettini Simona , Raiteri Luca , Passalacqua Mario , Melloni Edon , Venturi Consuelo , Tacchetti Carlo , Diaspro Alberto , Usai Cesare , Bonanno Giambattista 
Published: January 2006

AbstractGlial subcellular re‐sealed particles (referred to as gliosomes here) were purified from rat cerebral cortex and investigated for their ability to release glutamate. Confocal microscopy showed that the glia‐specific proteins glial fibrillary acidic protein (GFAP) and S‐100, but not the neuronal proteins 95‐kDa postsynaptic density protein (PSD‐95), microtubule‐associated protein 2 (MAP‐2) and β‐tubulin III, were enriched in purified gliosomes. Furthermore, gliosomes exhibited labelling neither for integrin‐αM nor for myelin basic protein, which are specific for microglia and oligodendrocytes respectively. The Ca2+ ionophore ionomycin (0.1–5 µm) efficiently stimulated the release of tritium from gliosomes pre‐labelled with [3H]d‐aspartate and of endogenous glutamate in a Ca2+‐dependent and bafilomycin A1‐sensitive manner, suggesting the involvement of an exocytotic process. Accordingly, ionomycin was found to induce a Ca2+‐dependent increase in the vesicular fusion rate, when exocytosis was monitored with acridine orange. ATP stimulated [3H]d‐aspartate release in a concentration‐ (0.1–3 mm) and Ca2+‐dependent manner. The gliosomal fraction contained proteins of the exocytotic machinery [syntaxin‐1, vesicular‐associated membrane protein type 2 (VAMP‐2), 23‐kDa synaptosome‐associated protein (SNAP‐23) and 25‐kDa synaptosome‐associated protein (SNAP‐25)] co‐existing with GFAP immunoreactivity. Moreover, GFAP or VAMP‐2 co‐expressed with the vesicular glutamate transporter type 1. Consistent with ultrastructural analysis, several ∼30‐nm non‐clustered vesicles were present in the gliosome cytoplasm. It is concluded that gliosomes purified from adult brain contain glutamate‐accumulating vesicles and can release the amino acid by a process resembling neuronal exocytosis.
Controls on low‐pressure anatexis
Authors: GERBI C. C. , JOHNSON S. E. , KOONS P. O. 
Published: January 2006

AbstractLow‐pressure anatexis, whereby rocks melt in place after passing through the andalusite stability field, develops under more restricted conditions than does low‐pressure metamorphism. Our thermal modelling and review of published work indicate that the following mechanisms, operating alone, may induce anatexis in typical pelitic rocks without inducing wholesale melting in the lower crust: (i) magmatic advection by pervasive flow; (ii) crustal‐scale detachment faulting; and (iii) the presence of a high heat‐producing layer. Of these, only magmatic advection by pervasive flow and crustal‐scale detachment faulting have been shown quantitatively to provide sufficient heat to cause widespread melting. Combinations of the above mechanisms with pluton‐scale magmatic advection, shear heating, removal of the lithospheric mantle, or with each other provide additional means of developing suitable high temperatures at shallow crustal levels to generate low‐pressure anatexis.
Comparison of the Role of the Subcutaneous Tissues in Cutaneous Wound Healing in the Dog and Cat
Authors: BOHLING MARK W. , HENDERSON RALPH A. , SWAIM STEVEN F. , KINCAID STEVEN A. , WRIGHT JAMES C. 
Published: January 2006

Objective—To describe and compare the contribution of the subcutaneous tissues to 1st and 2nd intention cutaneous wound healing in the dog and cat.Study Design—Experimental study.Animals—Domestic shorthaired cats (n=6) and 6 beagle dogs.Methods—Paired wounds were created on either side of the dorsal midline; the subcutaneous tissue was removed on 1 side and left intact on the other. Square, open wounds of the dorsal aspect of the thorax were observed for 21 days to monitor granulation tissue formation, wound contraction, epithelialization, and total healing (contraction+epithelialization). Breaking strength of sutured linear wounds was measured 7 days after wounding. Laser‐Doppler perfusion imaging (LDPI) was used to measure cutaneous perfusion.Results—First intention healing: subcutaneous tissue removal had no consistent effect on sutured wound strength at 7 days in dogs or cats. Second intention healing: removal of subcutaneous tissue reduced wound perfusion, granulation, contraction, epithelialization, and total healing. Granulation tissue formation and wound contraction were delayed to a significantly greater degree in cats than in dogs (P<.05). Two dogs (33%) had minor wound infections.Conclusions—The subcutaneous tissues make an important contribution to 2nd intention cutaneous healing. Dog and cat wounds had delayed 2nd intention healing when subcutaneous tissues were removed; wounds in dogs, but not cats, had largely recovered from this delay by 21 days.Clinical Relevance—Extensive debridement of subcutaneous tissue may delay wound healing particularly in feline patients. A higher risk for wound infections may accompany extensive removal of subcutaneous tissues in dogs.