bluuebunny/crossref_metadata_2025_split huggingface dataset:
Divided we fail: the importance of social integration for the re‐introduction of endangered African wild dogs (Lycaon pictus)
Authors: Gusset M. , Slotow R. , Somers M. J. 
Published: June 2006

AbstractIn South Africa, a plan was launched to manage separate sub‐populations of endangered African wild dogs Lycaon pictus in several small, geographically isolated conservation areas as a single meta‐population. This intensive management approach involves the re‐introduction of wild dogs into suitable conservation areas and periodic translocations among them. Here, we sought to evaluate the relevance of taking the formation of new reproductive units into consideration in promoting such translocation attempts. For this purpose, we analysed the behavioural process of integrating translocated wild dogs into new packs in pre‐release holding facilities in Hluhluwe‐iMfolozi Park, one of the meta‐population conservation areas. In addition, we reviewed findings from other wild dog translocation attempts in regard to the outcome of using variously composed groups and captive‐bred animals for the artificial creation of new packs for translocation purposes. We show the importance of social integration before release for wild dog re‐introductions and translocations to be successful. We also present a set of proximate factors, including management manipulation of social relationships, which promote pack formation in pre‐release holding facilities. This demonstrably enhances the efficiency of costly wild dog re‐introductions and translocations, thereby illustrating the implications of sociality for endangered species recovery.
Prion protein reduces both oxidative and non‐oxidative copper toxicity
Authors: Haigh Cathryn L. , Brown David R. 
Published: June 2006

AbstractThe prion protein is a membrane tethered glycoprotein that binds copper. Conversion to an abnormal isoform is associated with neurodegenerative diseases known as prion diseases. Expression of the prion protein has been suggested to prevent cell death caused by oxidative stress. Using cell based models we investigated the potential of the prion protein to protect against copper toxicity. Although prion protein expression effectively protected neurones from copper toxicity, this protection was not necessarily associated with reduction in oxidative damage. We also showed that glycine and the prion protein could both protect neuronal cells from oxidative stress. Only the prion protein could protect these cells from the toxicity of copper. In contrast glycine increased copper toxicity without any apparent oxidative stress or lipid peroxidation. Mutational analysis showed that protection by the prion protein was dependent upon the copper binding octameric repeat region. Our findings demonstrate that copper toxicity can be independent of measured oxidative stress and that prion protein expression primarily protects against copper toxicity independently of the mechanism of cell death.
Glycine receptors: recent insights into their structural organization and functional diversity
Authors: Betz Heinrich , Laube Bodo 
Published: June 2006

AbstractStrychnine‐sensitive glycine receptors (GlyRs) are known to mediate synaptic inhibition in spinal cord, brainstem and other regions of the CNS. During the past 5 years, considerable progress has been made in delineating structural determinants of ligand binding and channel activation in recombinant GlyRs. Furthermore, immunohistochemical and gene inactivation studies have disclosed distinct distributions and functions of differentially expressed GlyR subtypes in retina, hippocampus and the dorsal horn of the spinal cord. Accordingly, GlyRs regulate not only the excitability of motor and sensory neurones, but are also essential for the processing of photoreceptor signals, neuronal development and inflammatory pain sensitization. Hence, these receptors constitute promising targets for the development of clinically useful compounds.
Defective axonal transport of neurofilament proteins in neurons overexpressing peripherin
Authors: Millecamps Stéphanie , Robertson Janice , Lariviere Roxanne , Mallet Jacques , Julien Jean‐Pierre 
Published: June 2006

AbstractPeripherin is a type III neuronal intermediate filament detected in motor neuron inclusions of amyotrophic lateral sclerosis (ALS) patients. We previously reported that overexpression of peripherin provokes late‐onset motor neuron dysfunction in transgenic mice. Here, we show that peripherin overexpression slows down axonal transport of neurofilament (NF) proteins, and that the transport defect precedes by several months the appearance of axonal spheroids in adult mice. Defective NF transport by peripherin up‐regulation was further confirmed with dorsal root ganglia (DRG) neurons cultured from peripherin transgenic embryos. Immunofluorescence microscopy and western blotting revealed that excess peripherin provokes reduction in levels of hyperphosphorylated NF‐H species in DRG neurites. Similarly the transport of a green fluorescent protein (GFP)‐tagged NF‐M, delivered by means of a lentiviral construct, was impaired in DRG neurites overexpressing peripherin. These results demonstrate that peripherin overexpression can cause defective transport of type IV NF proteins, a phenomenon that may account for the progressive formation of ALS‐like spheroids in axons.
Antagonism by imidazoline – type drugs of muscarinic and other receptors in the guinea‐pig ileum
Authors: Salazar‐Bookaman M. M. , Miller D. D. , Patil P. N. 
Published: June 2006

Summary1 Several imidazolines were examined for the antagonism of muscarinic (M3) and other receptors on the isolated ileum of guinea‐pig. The effect of the muscarinic agonist, carbachol was competitively antagonized by oxymetazoline at 10−5 m. A dissociation constant (KB) of 3.6 μmfor the antagonist was calculated. At higher concentrations, 3 × 10−5and 10−4 m, of the antagonist, the agonist dose–response curve was shifted to the right with a decrease in the maximum effect. Thus, a non‐competitive block occurred at higher concentrations of oxymetazoline. Blockade of histamine H, and serotonin receptor‐mediated responses by oxymetazoline were also of a non‐competitive type.2 Naphazoline at 10−4 mshifted the dose‐response curves of carbachol and serotonin to the right by two‐ and 15‐fold, respectively. The maximum contraction of the agonist was not affected. Tolazoline also had a weak antihistaminic activity. At similar concentration; tetrahydrozoline clonidine and phentolamine at 10−5 mproduced two‐, three‐ and four‐fold shift of the carbachol dose–response curve without significant changes in the maxima. Neither methoxamine, p‐amino‐clonidine nor cimetidine blocked the responses of carbachol.3 The isosteric nature of theα‐adrenoceptor agonist, oxymetazoline and some imidazolines with carbachol, in part, explains its molecular competition at the muscarinic M3receptor of the guinea‐pig ileum. Surprisingly, contractile effects of carbachol (M3), histamine (H1) or serotonin (5HT3/5HT4) were not influenced by methoxamine, tetrahydrozoline, p‐amino clonidine and cimetidine.
Muscarinic receptor subtypes in neuronal and non‐neuronal cholinergic function
Authors: Eglen R. M. 
Published: June 2006

Summary1 Muscarinic M1–M5receptors mediate the metabotropic actions of acetylcholine in the nervous system. A growing body of data indicate they also mediate autocrine functions of the molecule. The availability of novel and selective muscarinic agonists and antagonists, as well asin vivogene disruption techniques, has clarified the roles of muscarinic receptors in mediating both functions of acetylcholine.2 Selective M1agonists or mixed M1agonists/M2antagonists may provide an approach to the treatment of cognitive disorders, while M3antagonism, or mixed M2/M3antagonists, are approved for the treatment of contractility disorders including overactive bladder and chronic obstructive pulmonary disease. Preclinical data suggest that selective agonism of the M4receptor will provide novel anti‐nociceptive agents, while therapeutics‐based upon agonism or antagonism of the muscarinic M5receptor have yet to be reported.3 The autocrine functions of muscarinic receptors broadly fall into two areas – control of cell growth or proliferation and mediation of the release of chemical mediators from epithelial cells, ultimately causing muscle relaxation. The former particularly are involved in embryological development, oncogenesis, keratinocyte function and immune responsiveness. The latter regulate contractility of smooth muscle in the vasculature, airways and urinary bladder.4 Most attention has focused on muscarinic M1or M3receptors which mediate lymphocyte immunoresponsiveness, cell migration and release of smooth muscle relaxant factors. Muscarinic M4receptors are implicated in the regulation of keratinocyte adhesion and M2receptors in stem cell proliferation and development. Little data are available concerning the M5receptor, partly due to the difficulties in defining the subtype pharmacologically.5 The autocrine functions of acetylcholine, like those in the nervous system, involve activation of several muscarinic receptor subtypes. Consequently, the role of these subtypes in autocrine, as well neuronal cholinergic systems, significantly expands their importance in physiology and pathophysiology.
Regulation of bladder muscarinic receptor subtypes by experimental pathologies
Authors: Ruggieri M. R. , Braverman A. S. 
Published: June 2006

Summary1 The M3muscarinic receptor subtype is widely accepted as the receptor on smooth muscle cells that mediates cholinergic contraction of the normal urinary bladder and other smooth muscle tissues, however, we have found that the M2receptor participates in contraction under certain abnormal conditions. The aim of this study was to determine the effects of various experimental pathologies on the muscarinic receptor subtype mediating urinary bladder contraction.2 Experimental pathologies resulting in bladder hypertrophy (denervation and outlet obstruction) result in an up‐regulation of bladder M2receptors and a change in the receptor subtype mediating contraction from M3towards M2. Preventing the denervation‐induced bladder hypertrophy by urinary diversion prevents this shift in contractile phenotype indicating that hypertrophy is responsible as opposed to denervationper se.3 The hypertrophy‐induced increase in M2receptor density and contractile response is accompanied by an increase in the tissue concentrations of mRNA coding for the M2receptor subtype, however, M3receptor protein density does not correlate with changes in M3receptor tissue mRNA concentrations across different experimental pathologies.4 This shift in contractile phenotype from M3towards M2subtype is also observed in aged male Sprague–Dawley rats but not females or either sex of the Fisher344 strain of rats.5 Four repeated, sequential agonist concentration response curves also cause this shift in contractile phenotype in normal rat bladder stripsin vitro, as evidenced by a decrease in the affinity of the M3selective antagonistp‐fluoro‐hexahydro‐sila‐diphenidol (p‐F‐HHSiD).6 A similar decrease in the contractile affinity of M3selective antagonists (darifenacin andp‐F‐HHSiD) is also observed in bladder specimens from patients with neurogenic bladder as well as certain organ transplant donors.7 It is concluded that although the M3receptor subtype predominately mediates contraction under normal circumstances, the M2receptor subtype can take over a contractile role when the M3subtype becomes inactivated by, for example, repeated agonist exposures or bladder hypertrophy. This finding has substantial implications for the clinical treatment of abnormal bladder contractions.
The Effect of Two Publicly Funded Insurance Programs on Use of Dental Services for Young Children
Authors: Brickhouse Tegwyn H. , Rozier R. Gary , Slade Gary D. 
Published: June 2006

Objective. The purpose of this study is to compare the use of dental services for preschool aged children enrolled in North Carolina Medicaid, a traditional program based on a fee‐for‐service schedule, and North Carolina Health Choice (NCHC), an State Children's Health Insurance Program (S‐CHIP) dental insurance program structured similarly to private insurance.Study Population. All children (165,858) 1–5 years of age enrolled in Medicaid and S‐CHIP (NCHC) at some time during one study year (October 1, 1999–September 30, 2000).Data Sources/Extraction Methods. Medicaid and NCHC enrollment and dental claims files were obtained for individual children.Study Design. An observational study with a retrospective cohort design. Use of dental services for each child was measured as having at least one dental claim during the outcome period (October 1, 1999–September 30, 2000). Multivariable logistic regression models were developed to compare the effect of two differently administered insurance programs on the use of dental services, controlling for demographic, enrollment, and county characteristics.Principle Findings. Children enrolled solely in S‐CHIP (NCHC) were 1.6 times more likely (95 percent confidence intervals (CI)=1.50–1.79) to have a dental visit than those enrolled solely in Medicaid. Prediction models for children enrolled for 12 months indicated that those enrolled in S‐CHIP (NCHC) had a significantly higher probability of having a dental visit (50 percent) than those enrolled in both plans (44 percent) or Medicaid only (39 percent), a trend found in all age groups.Conclusions. The S‐CHIP (NCHC) program appears to provide children with increased access to dental care compared to children in the Medicaid program.
Learning from Doing Participatory Rural Research: Lessons from the Peak District National Park
Authors: Dougill A. J. , Fraser E. D. G. , Holden J. , Hubacek K. , Prell C. , Reed M. S. , Stagl S. , Stringer L. C. 
Published: June 2006

AbstractUnderstanding the socio‐economic and environmental implications of rural change requires the active participation of many research disciplines and stakeholders. However, it remains unclear how to best integrate participatory and biophysical research to provide information useful to land managers and policy makers. This paper presents findings of a RELU scoping study that has formulated and applied a research framework based on stakeholder participation and adaptive learning to model rural change in the Peak District National Park in the north of England. The paper describes a learning process that integrates different types of knowledge to produce future scenarios that describe possible economic and environmental changes due to a national review of burning practices on heather moorland and blanket bogs. We stress the need for using social network analysis to structure stakeholder engagement and outline how a range of participatory approaches can facilitate more inclusive environmental planning and policy development.
Understanding Loweswater: Interdisciplinary Research in Practice
Authors: Waterton Claire , Norton Lisa , Morris Jake 
Published: June 2006

AbstractThis paper reports on a scoping study, ‘Understanding Loweswater’, funded under the Rural Economy and Land Use (RELU) programme. It highlights the research and policy context supporting the need for this kind of interdisciplinary, stakeholder‐inclusive research and explains the way that the research was carried out in practice. The scoping study identified some of the challenges of the interdisciplinary approach taken, as well as highlighted its potential for solving environmental problems that do not fit within the frame of a single discipline.
Eccentric rehabilitation exercise increases peritendinous type I collagen synthesis in humans with Achilles tendinosis
Authors: Langberg H. , Ellingsgaard H. , Madsen T. , Jansson J. , Magnusson S. P. , Aagaard P. , Kjær M. 
Published: June 2006

It has been shown that 12 weeks of eccentric heavy resistance training can reduce pain in runners suffering from chronic Achilles tendinosis, but the mechanism behind the effectiveness of this treatment is unknown. The present study investigates the local effect of an eccentric training regime on elite soccer players suffering from chronic Achilles tendinosis on the turnover of the peritendinous connective tissue.Twelve elite male soccer players, of whom six suffered from unilateral tendinosis and six were healthy controls, participated in this study. All participants performed 12 weeks of heavy‐resistance eccentric training apart from their regular training and soccer activity. Before and after the training period the tissue concentration of indicators of collagen turnover was measured by the use of the microdialysis technique. After training, collagen synthesis was increased in the initially injured tendon (n=6; carboxyterminal propeptide of type I collagen (PICP): pre 3.9±2.5 μg/L to post 19.7±5.4 μg/L, P<0.05). The collagen synthesis was unchanged in healthy tendons in response to training (n=6; PICP: pre 8.3±5.2 μg/L to post 11.5±5.0 μg/L, P>0.05). Collagen degradation, measured as carboxyterminal telopeptide region of type I collagen (ICTP), was not affected by training neither in the injured nor in the healthy tendons. The clinical effect of the 12 weeks of eccentric training was determined by using a standardized loading procedure of the Achilles tendons showing a decrease in pain in all the chronic injured tendons (VAS before 44±9, after 13±9; P<0.05), and all subjects were back playing soccer following the eccentric training regime.The present study demonstrates that chronically injured Achilles tendons respond to 12 weeks of eccentric training by increasing collagen synthesis rate. In contrast, the collagen metabolism in healthy control tendons seems not to be affected by eccentric training. These findings could indicate a relation between collagen metabolism and recovery from injury in human tendons.
Reproducibility and relationship of single‐joint strength vs multi‐joint strength and power in aging individuals
Authors: Holsgaard Larsen A. , Caserotti P. , Puggaard L. , Aagaard P. 
Published: June 2006

Introduction: Reliable and sensitive muscle strength/power assessments are essential when evaluating age‐related and/or training‐induced changes in maximal strength and power.Aim: To investigate the reproducibility and inter‐relationship of single‐joint isokinetic/isometric leg muscle strength vs multi‐joint mechanical muscle function during counter‐movement jump (CMJ) in moderately trained aging individuals (age 72.3±6.6).Results: The within‐subject coefficient of variation (CVw‐s) for the single‐joint test showed good reproducibility (<10%) for quadriceps and hamstring strength (except for hamstring isometric). Plantar flexion demonstrated good to moderate reproducibility (CVw‐s range: 10.4–17.2%). Excellent to good CVw‐s (<10%) was observed for all concentric CMJ parameters, except for plantar flexor mean work (CVw‐s=13%). Eccentric CMJ parameters demonstrated good to moderate reproducibility (CVw‐s range: 8.1–18.2%). Isokinetic and isometric quadriceps, hamstring and plantar flexor single‐joint strength measurements were found to correlate with several CMJ parameters.Conclusion: Single‐joint and multi‐joint strength and power assessment tests of the lower limbs appear to be reproducible in aging individuals. Furthermore, associations between single‐joint strength and multi‐joint CMJ power and force variables exist. To evaluate functional capacity in elderly people further investigations must be carried out to identify specific power/strength parameters that are most tightly linked to functional performance.
FixJ: a Major Regulator of the Oxygen Limitation Response and Late Symbiotic Functions of
Sinorhizobium meliloti
Authors: Bobik Christine , Meilhoc Eliane , Batut Jacques 
Published: June 2006

ABSTRACT

Sinorhizobium meliloti
exists either in a free-living state in the soil or in
symbiosis within legume nodules, where the bacteria differentiate into
nitrogen-fixing bacteroids. Expression of genes involved in nitrogen
fixation and associated respiration is governed by two intermediate
regulators, NifA and FixK, respectively, which are controlled by a
two-component regulatory system FixLJ in response to low-oxygen
conditions. In order to identify the FixLJ regulon, gene expression
profiles were determined in microaerobic free-living cells as well as
during the symbiotic life of the bacterium for the wild type and a
fixJ
null-mutant strain. We identified 122 genes activated by
FixJ in either state, including 87 novel targets. FixJ controls 74% of
the genes induced in microaerobiosis (2% oxygen) and the majority of
genes expressed in mature bacteroids. Ninety-seven percent of
FixJ-activated genes are located on the symbiotic plasmid pSymA.
Transcriptome profiles of a
nifA
and a
fixK
mutant
showed that NifA activates a limited number of genes, all specific to
the symbiotic state, whereas FixK controls more than 90 genes, involved
in free-living and/or symbiotic life. This study also revealed that
FixJ has no other direct targets besides those already known. FixJ is
involved in the regulation of functions such as denitrification or
amino acid/polyamine metabolism and transport. Mutations in selected
novel FixJ targets did not affect the ability of the bacteria to form
nitrogen-fixing nodules on
Medicago sativa
roots. From these
results, we propose an updated model of the FixJ
regulon.
Site-Directed Amino Acid Substitutions in the Hydroxylase α Subunit of Butane Monooxygenase from
Pseudomonas butanovora
: Implications for Substrates Knocking at the Gate
Authors: Halsey Kimberly H. , Sayavedra-Soto Luis A. , Bottomley Peter J. , Arp Daniel J. 
Published: June 2006

ABSTRACT

Butane monooxygenase (BMO) from
Pseudomonas butanovora
has high homology to soluble methane monooxygenase (sMMO), and both oxidize a wide range of hydrocarbons; yet previous studies have not demonstrated methane oxidation by BMO. Studies to understand the basis for this difference were initiated by making single-amino-acid substitutions in the hydroxylase α subunit of butane monooxygenase (BMOH-α) in
P. butanovora
. Residues likely to be within hydrophobic cavities, adjacent to the diiron center, and on the surface of BMOH-α were altered to the corresponding residues from the α subunit of sMMO. In vivo studies of five site-directed mutants were carried out to initiate mechanistic investigations of BMO. Growth rates of mutant strains G113N and L279F on butane were dramatically slower than the rate seen with the control
P. butanovora
wild-type strain (Rev WT). The specific activities of BMO in these strains were sevenfold lower than those of Rev WT. Strains G113N and L279F also showed 277- and 5.5-fold increases in the ratio of the rates of 2-butanol production to 1-butanol production compared to Rev WT. Propane oxidation by strain G113N was exclusively subterminal and led to accumulation of acetone, which
P. butanovora
could not further metabolize. Methane oxidation was measurable for all strains, although accumulation of 23 μM methanol led to complete inhibition of methane oxidation in strain Rev WT. In contrast, methane oxidation by strain G113N was not completely inhibited until the methanol concentration reached 83 μM. The structural significance of the results obtained in this study is discussed using a three-dimensional model of BMOH-α.
Involvement of Y-Family DNA Polymerases in Mutagenesis Caused by Oxidized Nucleotides in
Escherichia coli
Authors: Yamada Masami , Nunoshiba Tatsuo , Shimizu Masatomi , Gruz Petr , Kamiya Hiroyuki , Harashima Hideyoshi , Nohmi Takehiko 
Published: June 2006

ABSTRACT

Escherichia coli
DNA polymerase IV incorporated 2-hydroxy-dATP opposite template guanine or thymine and 8-hydroxy-dGTP exclusively opposite adenine in vitro. Mutator phenotypes in
sod/fur
strains were substantially diminished by deletion of
dinB
and/or
umuDC
. DNA polymerases IV and V may be involved in mutagenesis caused by incorporation of the oxidized deoxynucleoside triphosphates.