bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of β3‐adrenoceptors in mediating relaxation of porcine detrusor muscle
Authors: Yamanishi Tomonori , Chapple Christopher R , Yasuda Kosaku , Yoshida Kenichiro , Chess‐Williams Russell
Published: June 2006

β‐adrenoceptors mediate relaxation of bladder detrusor smooth muscle. This study investigates the contribution of β3‐adrenoceptors to relaxation of the pig urinary bladder.

Cell membranes were prepared from detrusor muscle of the pig bladder dome and competition experiments with [3H]‐dihydroalprenolol (DHA), a non‐selective β‐adrenoceptor antagonist was used as a specific radioligand to determine the presence of β‐adrenoceptor subtypes. In functional experiments, isolated detrusor muscle strips were used to determine the potency of agonists and the affinity of antagonists.

In competition binding experiments, CGP20712A (β1‐adrenoceptor selective) displaced [3H]‐DHA from a single binding site with a low affinity. In contrast, displacement data for ICI 118551 (β2‐adrenoceptor antagonist) and SR59230A (β3‐adrenoceptor antagonist) best fitted a two‐site model suggesting a predominant (70%) population of β3‐adrenoceptors.

In functional studies, isoprenaline and salbutamol (β2‐adrenoceptor agonist) relaxed KCl precontracted muscle strips with high potency (pEC507.7 and 7.2, respectively), whilst CGP12177 and BRL37344 (β3‐adrenoceptor agonists) had low potency and were partial agonists. CGP20712A and atenolol (β1‐adrenoceptor antagonists) antagonised responses with a low affinity. ICI118551 antagonized responses to isoprenaline and salbutamol with a high affinity (pKB=7.8 and 8.7, respectively), but the Schild slopes were low suggesting that responses were mediated by more than one β‐adrenoceptor. The Schild plot for SR59230A was biphasic, apparent pKBvalues for 3 – 10 nMSR59230A being 8.6 and those for 30 nM – 1 μMbeing 7.7.

These data suggest that β3‐adrenoceptors are the predominant β‐adrenoceptor subtype present in the pig bladder and that β‐adrenoceptor mediated responses of this tissue are mediatedviaboth the β2‐ and β3‐adrenoceptor subtypes.

British Journal of Pharmacology(2002)135, 129–134; doi:10.1038/sj.bjp.0704470
Presynaptic modulation of cholinergic neurotransmission in the human proximal stomach
Authors: Leclere Pascal G , Lefebvre Romain A
Published: June 2006

This study investigates whether the cholinergic neurones, innervating the human proximal stomach, can be modulated by nitric oxide (NO) or vasoactive intestinal polypeptide (VIP), orviapresynaptic muscarinic, α2‐ or 5‐hydroxytryptamine4(5‐HT4‐) receptors.

Circular muscle strips, without mucosa, were incubated with [3H]‐choline to incorporate [3H]‐acetylcholine into the cholinergic transmitter stores. The basal and electrically‐induced release of tritium and [3H]‐acetylcholine were analysed in a medium containing guanethidine (4×10−6 M), hemicholinium‐3 (10−5 M), physostigmine (10−5 M) and atropine (10−6 M). Tissues were stimulated twice for 2 min (S1and S2: 40 V, 1 ms, 4 Hz) and drugs were added before S2.

The NO synthase inhibitorL‐NG‐nitroarginine methyl ester (3×10−4 M) and the NO donor sodium nitroprusside (10−5 M), as well as VIP (10−7 M) did not influence the basal release nor the electrically‐evoked release.

The α2‐adrenoceptor agonist UK‐14,304 (10−5 M) significantly inhibited the electrically‐evoked release of [3H]‐acetylcholine, and this was prevented by the α2‐adrenoceptor antagonist rauwolscine (2×10−6 M).

The 5‐HT4‐receptor agonist prucalopride (3×10−7 M) significantly enhanced the electrically‐evoked release of [3H]‐acetylcholine, and the 5‐HT4‐receptor antagonist SB204070 (10−9 M) prevented this.

When atropine (10−6 M) was omitted from the medium and added before the second stimulation, it significantly increased the release of [3H]‐acetylcholine.

These results suggest that the release of acetylcholine from the cholinergic neurones, innervating the circular muscle in the human proximal stomach, can be inhibitedviapresynaptic muscarinic auto‐receptors and α2‐adrenoceptors, and stimulatedviapresynaptic 5‐HT4‐receptors. No evidence for modulation by NO or VIP was obtained.

British Journal of Pharmacology(2002)135, 135–142; doi:10.1038/sj.bjp.0704471
Pharmacological properties of nociceptin/orphanin FQ‐induced stimulation and inhibition of cyclic AMP formation in distinct layers of rat olfactory bulb
Authors: Olianas Maria C , Onali Pierluigi
Published: June 2006

We recently reported that nociceptin/orphanin FQ (N/OFQ) inhibited forskolin‐stimulated adenylyl cyclase activity and increased basal enzyme activity in membranes of the external plexiform layer (EPL) and granule cell layer (GRL), respectively, of the rat main olfactory bulb. In the present study we have characterized the pharmacological profile of the inhibitory and stimulatory responses by examining the effects of various N/OFQ receptor agonists and antagonists.

N/OFQ(1 – 13)NH2fully mimicked the inhibitory and stimulatory effects of N/OFQ with EC50values of 0.9 and 6.5 nM, respectively. N/OFQ(1 – 7) was inactive at concentrations up to 1 μM, whereas Ac‐RYYRIK‐NH2and [Phe1Ψ(CH2NH)Gly2]N/OFQ(1 – 13)‐NH2behaved as partial agonists in eliciting both responses.

The nonpeptidyl N/OFQ receptor antagonist J‐113397 competitively counteracted the inhibitory and stimulatory effects of N/OFQ with pA2values of 8.63 and 8.70, respectively. Similarly, the peptidyl antagonist [Nphe1]N/OFQ(1 – 13)NH2potently antagonized the two effects with pA2values of 8.03 and 8.45, respectively. None of the antagonistsper seaffected adenylyl cyclase activity.

These data show that in distinct layers of rat olfactory bulb both the inhibitory and stimulatory effects of N/OFQ on cyclic AMP formation display pharmacological properties consistent with the involvement of N/OFQ receptors.

British Journal of Pharmacology(2002)135, 233–238; doi:10.1038/sj.bjp.0704477
Evaluation of Tracer Kinetic Models for Quantification of P-Glycoprotein Function using (R)-[11C]Verapamil and PET
Authors: Lubberink Mark , Luurtsema Gert , van Berckel Bart NM , Boellaard Ronald , Toornvliet Rolf , Windhorst Albert D , Franssen Eric JF , Lammertsma Adriaan A
Published: June 2006

Diminished P-glycoprotein ( P-gp)-mediated transport across the Blood–brain barrier may play an important role in several neurodegenerative disorders. In previous studies, a racemic mixture of ( R)-[11C]verapamil and ( S)-[11C]verapamil has been used as tracer for assessing P-gp function using positron emission tomography (PET). Quantification, however, is compromised by potential differences in kinetics between these two isomers. The aim of the present study was to evaluate the kinetics of pure ( R)-[11C]verapamil in humans and to develop a tracer kinetic model for the analysis of P-gp-mediated transport of ( R)-[11C]verapamil, including the putative contribution of its radioactive metabolites. Dynamic ( R)-[11C]verapamil PET scans of 10 male volunteers were analysed with various single- or two-tissue compartment models, with separate compartments for N-dealkylated and N-demethylated metabolites, assuming that either ( R)-[11C]verapamil alone or ( R)-[11C]verapamil and any combination of metabolites cross the BBB. In addition, six of the subjects underwent two ( R)-[11C]verapamil scans to evaluate test–retest reliability. One hour after injection, 50% of total plasma radioactivity consisted of labelled metabolites. Most models fitted the data well and the analysis did not point to a definite ‘best’ model, with differences in optimal model between subjects. The lowest mean test–retest variability (2.9%) was found for a single-tissue model without any metabolite correction. Models with separate metabolite compartments lead to high test–retest variability. Assuming that differences in kinetics of ( R)-[11C]verapamil and N-dealkylated metabolites are small, a one input, one-tissue model with correction for N-demethylated metabolites only leads to a good compromise between fit quality and test–retest variability.
Modulation of Kv2.1 channel gating and TEA sensitivity by distinct domains of SNAP-25
Authors: He Yan , Kang Youhou , Leung Yuk-Man , Xia Fuzhen , Gao Xiaodong , Xie Huanli , Gaisano Herbert Y. , Tsushima Robert G.
Published: June 2006

Distinct domains within the SNARE (soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor) proteins, STX1A (syntaxin 1A) and SNAP-25 (synaptosome-associated protein-25 kDa), regulate hormone secretion by their actions on the cell's exocytotic machinery, as well as voltage-gated Ca2+ and K+ channels. We examined the action of distinct domains within SNAP-25 on Kv2.1 (voltage gated K+ 2.1) channel gating. Dialysis of N-terminal SNAP-25 domains, S197 (SNAP-251–197) and S180 (SNAP-251–180), but not S206 (full-length SNAP-251–206) increased the rate of Kv2.1 channel activation and slowed channel inactivation. Remarkably, these N-terminal SNAP-25 domains, acting on the Kv2.1 cytoplasmic N-terminus, potentiated the external TEA (tetraethylammonium)-mediated block of Kv2.1. To further examine whether these are effects of the channel pore domain, internal K+ was replaced with Na+ and external K+ was decreased from 4 to 1 mM, which decreased the IC50 of the TEA block from 6.8±0.9 mM to >100 mM. Under these conditions S180 completely restored TEA sensitivity (7.9±1.5 mM). SNAP-25 C-terminal domains, SNAP-25198–206 and SNAP-25181–197, had no effect on Kv2.1 gating kinetics. We conclude that different domains within SNAP-25 can form distinct complexes with Kv2.1 to execute a fine allosteric regulation of channel gating and the architecture of the outer pore structure in order to modulate cell excitability.
Recombinant human hyaluronan synthase 3 is phosphorylated in mammalian cells
Authors: Goentzel Brian J. , Weigel Paul H. , Steinberg Robert A.
Published: June 2006

Hyaluronan is a ubiquitous component of vertebrate extracellular and cell-associated matrices that serves as a key structural component of skin, cartilage, eyes and joints, and plays important roles in dynamic cellular processes, including embryogenesis, inflammation, wound healing and metastasis. Hyaluronan is synthesized by three homologous hyaluronan synthases designated HAS1, HAS2 and HAS3 that differ in their tissue distribution, regulation and enzymatic characteristics. Some progress has been made in characterizing regulation of HAS transcripts and in distinguishing the enzymatic properties of the various HAS isoforms, but essentially nothing is known about their possible regulation by posttranslational modification. Using [32P]Pi radiolabelling of a recombinant FLAG (DYKDDDDK) epitope-tagged version of human HAS3 expressed in COS-7 cells, we show that HAS3 is serine-phosphorylated and that this phosphorylation can be enhanced by a number of effectors – most significantly by a membrane-permeable analogue of cAMP. By employing a novel FLAG-tagged phosphorylated reference protein derived from EGFP (enhanced green fluorescent protein), we were able to estimate the stoichiometry of FLAG–HAS3 phosphorylation. It was approx. 0.11 in unstimulated cells and increased to as much as 0.32 in cells stimulated with 8-(4-chlorophenylthio)-cAMP.
Phosphatidylinositol synthesis is essential in bloodstream form Trypanosoma brucei
Authors: Martin Kirstee L. , Smith Terry K.
Published: June 2006

PI (phosphatidylinositol) is a ubiquitous eukaryotic phospholipid which serves as a precursor for messenger molecules and GPI (glycosylphosphatidylinositol) anchors. PI is synthesized either de novo or by head group exchange by a PIS (PI synthase). The synthesis of GPI anchors has previously been validated both genetically and chemically as a drug target in Trypanosoma brucei, the causative parasite of African sleeping sickness. However, nothing is known about the synthesis of PI in this organism. Database mining revealed a putative TbPIS gene in the T. brucei genome and by recombinant expression and characterization it was shown to encode a catalytically active PIS, with a high specificity for myo-inositol. Immunofluorescence revealed that in T. brucei, PIS is found in both the endoplasmic reticulum and Golgi. We created a conditional double knockout of TbPIS in the bloodstream form of T. brucei, which when grown under non-permissive conditions, clearly showed that TbPIS is an essential gene. In vivo labelling of these conditional double knockout cells confirmed this result, showing a decrease in the amount of PI formed by the cells when grown under non-permissive conditions. Furthermore, quantitative and qualitative analysis by GLC-MS and ESI-MS/MS (electrospray ionization MS/MS) respectively showed a significant decrease (70%) in cellular PI, which appears to affect all major PI species equally. A consequence of this fall in PI level is a knock-on reduction in GPI biosynthesis which is essential for the parasite's survival. The results presented here show that PI synthesis is essential for bloodstream form T. brucei, and to our knowledge this is the first report of the dependence on PI synthesis of a protozoan parasite by genetic validation.
Engineered covalent leucotoxin heterodimers form functional pores: insights into S–F interactions
Authors: Joubert Olivier , Viero Gabriella , Keller Daniel , Martinez Eric , Colin Didier A. , Monteil Henri , Mourey Lionel , Dalla serra Mauro , Prévost Gilles
Published: June 2006

The staphylococcal α-toxin and bipartite leucotoxins belong to a single family of pore-forming toxins that are rich in β-strands, although the stoichiometry and electrophysiological characteristics of their pores are different. The different known structures show a common β-sandwich domain that plays a key role in subunit–subunit interactions, which could be targeted to inhibit oligomerization of these toxins. We used several cysteine mutants of both HlgA (γ-haemolysin A) and HlgB (γ-haemolysin B) to challenge 20 heterodimers linked by disulphide bridges. A new strategy was developed in order to obtain a good yield for S-S bond formation and dimer stabilization. Functions of the pores formed by 14 purified dimers were investigated on model membranes, i.e. planar lipid bilayers and large unilamellar vesicles, and on target cells, i.e. rabbit and human red blood cells and polymorphonuclear neutrophils. We observed that dimers HlgA T28C–HlgB N156C and HlgA T21C–HlgB T157C form pores with similar characteristics as the wild-type toxin, thus suggesting that the mutated residues are facing one another, allowing pore formation. Our results also confirm the octameric stoichiometry of the leucotoxin pores, as well as the parity of the two monomers in the pore. Correctly assembled heterodimers thus constitute the minimal functional unit of leucotoxins. We propose amino acids involved in interactions at one of the two interfaces for an assembled leucotoxin.
Phenotypic responses to mechanical stress in fibroblasts from tendon, cornea and skin
Authors: Mackley Jennifer R. , Ando Joji , Herzyk Pawel , Winder Steven J.
Published: June 2006

Primary fibroblasts isolated from foetal mouse cornea, skin and tendon were subjected to linear shear stress and analysed for morphological parameters and by microarray, as compared with unstimulated controls. Approx. 350 genes were either up- or down-regulated by a significant amount, with 51 of these being common to all three cell types. Approx. 50% of altered genes in tendon and cornea fibroblasts were changed in common with one of the other cell types, with the remaining approx. 50% being specific to tendon or cornea. In skin fibroblasts, however, less than 25% of genes whose transcription was altered were specific only to skin. The functional spectrum of genes that were up- or down-regulated was diverse, with apparent house-keeping genes forming the major category of up-regulated genes. However, a significant number of genes associated with cell adhesion, extracellular matrix and matrix remodelling, as well as cytokines and other signalling factors, were also affected. Somewhat surprisingly, in these latter categories the trend was towards a reduction in mRNA levels. Verification of the mRNA quantity of a subset of these genes was performed by reverse transcriptase PCR and was found to be in agreement with the microarray analysis. These findings provide the first in-depth analysis of phenotypic differences between fibroblast cells from different tissue sources and reveal the responses of these cells to mechanical stress.
Calcium-dependent and -independent interactions of the S100 protein family
Authors: Santamaria-Kisiel Liliana , Rintala-Dempsey Anne C. , Shaw Gary S.
Published: June 2006

The S100 proteins comprise at least 25 members, forming the largest group of EF-hand signalling proteins in humans. Although the proteins are expressed in many tissues, each S100 protein has generally been shown to have a preference for expression in one particular tissue or cell type. Three-dimensional structures of several S100 family members have shown that the proteins assume a dimeric structure consisting of two EF-hand motifs per monomer. Calcium binding to these S100 proteins, with the exception of S100A10, results in an approx. 40° alteration in the position of helix III, exposing a broad hydrophobic surface that enables the S100 proteins to interact with a variety of target proteins. More than 90 potential target proteins have been documented for the S100 proteins, including the cytoskeletal proteins tubulin, glial fibrillary acidic protein and F-actin, which have been identified mostly from in vitro experiments. In the last 5 years, efforts have concentrated on quantifying the protein interactions of the S100 proteins, identifying in vivo protein partners and understanding the molecular specificity for target protein interactions. Furthermore, the S100 proteins are the only EF-hand proteins that are known to form both homo- and hetero-dimers, and efforts are underway to determine the stabilities of these complexes and structural rationales for their formation and potential differences in their biological roles. This review highlights both the calcium-dependent and -independent interactions of the S100 proteins, with a focus on the structures of the complexes, differences and similarities in the strengths of the interactions, and preferences for homo- compared with hetero-dimeric S100 protein assembly.
Effects of lairage time and electrical stimulation on sheep meat quality
Authors: Toohey E. S. , Hopkins D. L.
Published: June 2006

This paper describes an experiment which examined the effects of lairage time and electrical stimulation on meat quality and carcass traits in conventionally chilled sheep meat. The 120 Merino wethers used in this experiment were sourced on farm and were transported to the abattoir and held in a paddock 1 week before slaughter. The animals were then placed into 2 different pens (replicas). The sheep were killed at random either at day 1 (n = 60) or day 2 (n = 60). There were 30 animals taken from both pens 1 and 2 each day. Half of these animals were exposed to high voltage stimulation (30 stimulated) and for the other half the high voltage stimulation was turned off (30 control) each day. There was no significant (P>0.05) effect of lairage time on hot carcass weight, GR, initial pH, shear force or cooking loss. However, lairage time had a significant (P<0.05) effect on final pH and the temperature when the pH reached 6.0. Initial pH, final pH (21 h) and temperature at pH 6.0 were significantly different (P<0.05) between stimulated and non-stimulated carcasses, but there was no effect on cook loss or shear force (P>0.05). A significant (P<0.05) interaction between lairage time and stimulation was found for shear force which showed that non-stimulated meat from sheep held in lairage for 2 days was tougher than that from stimulated carcasses.
Quantifying the rate of pH and temperature decline in lamb carcasses at three abattoirs in New South Wales
Authors: Toohey E. S. , Hopkins D. L. , McLeod B. M. , Nielsen S. G.
Published: June 2006

The aim of this work was to benchmark the rate of pH and temperature decline in lamb carcasses (particularly the temperature at pH 6.0) at 3 commercial abattoirs across New South Wales. In total, 1197 carcasses were monitored over 13 months for pH and temperature decline. The lambs were sourced from a variety of regions, either direct from the paddock or from sale yards. Carcass weight was not significantly (P>0.05) different between abattoirs or seasons. There was a significant (P<0.05) interaction between abattoir and season for carcass fat depth at the 12th rib (GR) when adjusted to the same hot carcass weight, such that as carcass weight increased so did GR with changes in the relationship between seasons and abattoirs. The predicted pH at 3 h was significantly different between abattoirs, with abattoirs A and B having a significantly (P<0.05) higher pH than abattoir C. All abattoirs were different (P<0.05) for predicted temperature at 3 h, with abattoir A having the lowest and C having the highest temperature. Predicted pH at both 25 and 18°C were significantly different (P<0.05) between abattoirs, with abattoir C having the lowest and abattoir A having the highest pH at both temperatures. Abattoir A and B were not different for predicted temperature at pH 6.0, but abattoir C had a significantly higher temperature (P<0.05). Over all abattoirs only 18.8% of sampled carcasses complied with the recommended pH–temperature window of 18–25°C at pH 6.0. Of the carcasses sampled, 79.4% had a slow rate of pH decline and did not reach the onset of rigor (pH 6.0) by 18°C.
Methodology for assessing optimal rates of pasture improvement in the high rainfall temperate pasture zone
Authors: Behrendt K. , Cacho O. , Scott J. M. , Jones R.
Published: June 2006

Pasture improvement is a well-established technology for increasing production in extensive livestock grazing industries by changing pasture composition and increasing soil fertility. The Cicerone Project farmlets located at Chiswick Research Station, near Armidale in New South Wales, are providing valuable information at a credible scale on the response to 3 different management systems varying in levels of inputs and grazing management. The purpose of this paper is to outline a methodology for assessing farmlet performance in such studies. The assessment focuses on the stochastic efficiency of the different treatments. The impact of pasture persistence, climatic risk, and stochastic commodity prices on optimal rates of farm development are explored by using preliminary data from the Cicerone farmlets to calibrate the GrassGro model. The farmlets modelled represent 2 technology packages. One is a moderate-input package and the other is a high-input package. Preliminary analysis indicates that direct comparison of the 2 farmlets may produce the wrong assessment, because 1 farmlet is operating at a suboptimal level of efficiency in a stochastic sense. This means that direct comparisons of technologies based on the field data may be biased as the technologies should be evaluated at the risk-efficient frontier. The concept of a risk efficient frontier is explained and applied to aid in identifying the trade-offs between profit and risk, and identify differences in the efficiency of the 2 farmlets.
Wool weathering damage as measured by Methylene Blue absorption is linked to suint content
Authors: Dowling M. E. , Schlink A. C. , Greeff J. C.
Published: June 2006

Weather damage of wool in grazing sheep has long been recognised by the wool industry as a problem, resulting in fibre damage, fibre loss and poor dyeing performance. Merino wool from 3538 ewe and ram hoggets was used to estimate the heritability of Methylene Blue absorption. Methylene Blue absorption has a high heritability of 0.44 ± 0.04 and was strongly genetically correlated with suint index (0.88 ± 0.02) and wool moisture index (0.92 ± 0.03). Methylene Blue absorption was moderately genetically, negatively correlated with measures of clean wool colour and yield and positively with dust penetration. There was no significant correlation between Methylene Blue absorption and dust content or economically important measures of fleece value such as fibre diameter, curvature and staple strength. The strong genetic relationship between Methylene Blue absorption and suint index indicates that Methylene Blue absorption is a very good indirect measure of greasy wool suint content but may not be a satisfactory indicator trait to select for low weather damage.
Inheritance of Acid Red 1 dye absorption and its relationship to other Merino wool traits
Authors: Schlink A. C. , Ortega S. , Greeff J. C. , Dowling M. E.
Published: June 2006

Optimising and ensuring the reproducibility of wool dyeing is of significant economic importance to the wool industry. Midside wool from 1824 Merino ewe and ram hoggets was used to estimate the heritability of Acid Red 1 dye absorption in clean wool. Acid Red 1 absorption had a high heritability of 0.45 ± 0.07 and was phenotypically poorly correlated with fibre diameter (–0.11 ± 0.03), the coefficient of variation of fibre diameter (0.05 ± 0.03), curvature (–0.05 ± 0.03), staple strength (–0.02 ± 0.02) and staple length (–0.09 ± 0.03), yield (0.08 ± 0.03) and dust penetration (0.07 ± 0.03). It was not genetically correlated with fibre diameter (–0.05 ± 0.09), the coefficient of variation of fibre diameter (0.02 ± 0.09), curvature (–0.09 ± 0.09), staple strength (–0.07 ± 0.10) or staple length (–0.03 ± 0.08), but weakly genetically correlated with yield (0.18 ± 0.08) and dust penetration (0.24 ± 0.12). Dye absorption was also genetically negatively correlated with wool felting as measured by feltball diameter (–0.26 ± 0.09). Acid Red 1 absorption was not genetically correlated with absorption of the cationic dye Methylene Blue. We suggest that there is a biological basis for differences between wools in dyeing performance and that this variation will depend on the class of dye being evaluated for wool dyeing.
The role of livestock in the management of dryland salinity
Authors: Masters D. , Edwards N. , Sillence M. , Avery A. , Revell D. , Friend M. , Sanford P. , Saul G. , Beverly C. , Young J.
Published: June 2006

Management of dryland salinity in Australia will require changes in the design and utilisation of plant systems in agriculture. These changes will provide new opportunities for livestock agriculture. In areas already affected by salt, a range of plants can be grown from high feeding value legumes with moderate salt tolerance through to highly salt tolerant shrubs. A hectare of these plants may support between 500 and 2000 sheep grazing days per year. The type of plants that can be grown and the subsequent animal production potential depend on a range of factors that contribute to the ‘salinity stress index’ of a site, including soil and groundwater salinity, the extent and duration of waterlogging and inundation, the pattern and quantity of annual rainfall, soil texture and chemistry, site topography and other site parameters. Where the salinity stress index is high, plant options will usually include a halophytic shrub that accumulates salt. High salt intakes by grazing ruminants depress feed intake and production. Where high and low salt feeds are available together, ruminants will endeavour to select a diet that optimises the overall feeding value of the ingested diet.
In areas that are not yet salt affected but contribute to groundwater recharge, perennial pasture species offer an opportunity for improved water and salt management both on-farm and at the catchments. If perennial pasture systems are to be adopted on a broad scale, they will need to be more profitable than current annual systems. In the high rainfall zones in Victoria and Western Australia, integrated bioeconomic and hydrological modelling indicates that selection of perennial pasture plants to match requirements of a highly productive livestock system significantly improves farm profit and reduces groundwater recharge. In the low to medium rainfall zones, fewer perennial plant options are available. However, studies aiming to use a palette of plant species that collectively provide resilience to the environment while maintaining profitable livestock production may also lead to new options for livestock in the traditional cropping zone.
GPR56, an atypical G protein-coupled receptor, binds tissue transglutaminase, TG2, and inhibits melanoma tumor growth and metastasis
Authors: Xu Lei , Begum Shahinoor , Hearn Jeremy D. , Hynes Richard O.
Published: June 2006

The survival and growth of tumor cells in a foreign environment is considered a rate-limiting step during metastasis. To identify genes that may be essential for this process, we isolated highly metastatic variants from a poorly metastatic human melanoma cell line and performed expression analyses of metastases and primary tumors from these cells.
GPR56
is among the genes markedly down-regulated in the metastatic variants. We show that overexpression of GPR56 suppresses tumor growth and metastasis, whereas reduced expression of GPR56 enhances tumor progression. Levels of GPR56 do not correlate with growth rate
in vitro
, suggesting that GPR56 may mediate growth suppression by interaction with a component in the tumor microenvironment
in vivo
. We show that GPR56 binds specifically to tissue transglutaminase, TG2, a widespread component of tissue and tumor stroma previously implicated as an inhibitor of tumor progression. We discuss the mechanisms whereby GPR56-TG2 interactions may suppress tumor growth and metastasis.
Remarkably high activities of testicular cytochrome
c
in destroying reactive oxygen species and in triggering apoptosis
Authors: Liu Zhe , Lin Hao , Ye Sheng , Liu Qin-ying , Meng Zhaohui , Zhang Chuan-mao , Xia Yongjing , Margoliash Emanuel , Rao Zihe , Liu Xiang-jun
Published: June 2006

Hydrogen peroxide (H
2
O
2
) is the major reactive oxygen species (ROS) produced in sperm. High concentrations of H
2
O
2
in sperm induce nuclear DNA fragmentation and lipid peroxidation and result in cell death. The respiratory chain of the mitochondrion is one of the most productive ROS generating systems in sperm, and thus the destruction of ROS in mitochondria is critical for the cell. It was recently reported that H
2
O
2
generated by the respiratory chain of the mitochondrion can be efficiently destroyed by the cytochrome
c
-mediated electron-leak pathway where the electron of ferrocytochrome
c
migrates directly to H
2
O
2
instead of to cytochrome
c
oxidase. In our studies, we found that mouse testis-specific cytochrome
c
(T-C
c
) can catalyze the reduction of H
2
O
2
three times faster than its counterpart in somatic cells (S-C
c
) and that the T-C
c
heme has the greater resistance to being degraded by H
2
O
2
. Together, these findings strongly imply that T-C
c
can protect sperm from the damages caused by H
2
O
2
. Moreover, the apoptotic activity of T-C
c
is three to five times greater than that of S-C
c
in a well established apoptosis measurement system using
Xenopus
egg extract. The dramatically stronger apoptotic activity of T-C
c
might be important for the suicide of male germ cells, considered a physiological mechanism that regulates the number of sperm produced and eliminates those with damaged DNA. Thus, it is very likely that T-C
c
has evolved to guarantee the biological integrity of sperm produced in mammalian testis.
Two-dimensional kinematics of the flat-walking Tennessee Walking Horse yearling
Authors: Nicodemus MC , Holt HM
Published: June 2006

Gaited horse research is limited, with the majority of the research focusing on the measurement of the temporal variables of adult-gaited horses. The objective was to measure the fore and hind limb kinematics of the flat-walking Tennessee Walking Horse (TWH) yearling. Four TWH yearlings were filmed at 60 Hz being led at a consistent flat walk that followed breed standards. Reflective markers attached along palpation points of the joint centres of the fore and hind limbs were tracked for five strides for each yearling. During stance, the elbow (154±3°), carpal (185±3°), fore (222±9 and 221±9°) and hind fetlocks (216±11°), hip (111±3°), stifle (157±4°) and tarsal (167±9°) joints demonstrated peak extension with the forelimb fetlock joint having double peaks of extension. During swing, the same joints demonstrated peak flexion with the elbow (109±3°) and hip (88±6°) peak flexion occurring later in the swing phase. The carpal (54±4°) joint demonstrated a greater range of motion than the tarsus (40±9°) with less vertical displacement. The hind fetlock (60±10°) had greater range of joint motion compared with the forelimb fetlock (45±8°), but lacked the double peak of extension during swing. Kinematic measurements will assist in objectively defining the gait for both clinical and performance applications.
Adult Pertussis Is Hazardous for the Newborn
Authors: Bamberger Ellen , Starets-Haham Orna , Greenberg David , Karidis Argyro , Porat Nurit , Bar-Joseph Gad , Gershtein Rosa , Srugo Isaac
Published: June 2006

We report 4 cases involving the likely transmission of pertussis from parents to newborns in a hospital setting. The adoption of proper infection control measures and targeted screening of parents may reduce the potential for such transmission.
Risk Factors for Candidemia in Pediatric Patients With Congenital Heart Disease
Authors: Miguel Lucía García-San , Cobo Javier , Martos Isabel , Otheo Enrique , Muriel Alfonso , Pintado Vicente , Moreno Santiago
Published: June 2006

Objective.

To identify the main risk factors for the acquisition of candidemia in children with congenital heart disease (CHD) in order to improve the clinical management of these patients.

Design.

A case-control study.

Setting.

A large tertiary-care referral center in Spain with a pediatric intensive care unit (PICU) to which more than 500 children with CHD are admitted annually.

Patients.

All patients had CHD and were admitted to the PICU during 1995-2000. Case patients were defined as patients with candidemia, and control patients were defined as patients without candidemia.

Results.

Twenty-eight case patients and 47 control subjects were included in the study. Case patients were younger (mean age [ ± SD], 12.5 ± 32.0 vs 38.0 ± 48.0 months;P< .01) and had a longer median PICU stay (19 vs 4 days;P< .01), and a greater percentage of case patients previously hadCandidaspecies isolated from specimens other than blood (eg, bronchial aspirates, urine, or skin specimens) (39% vs 4%;P<.01). Severity of clinical condition, as measured by the Therapeutic Intervention Scoring System (TISS) 1 week after PICU admission (odds ratio, 1.15; 95% confidence interval, 1.05-1.26;P<.01), and receipt of antibiotic treatment for more than 5 days (odds ratio, 13.42; 95% confidence interval, 1.31-137.13;P= .03) were independently associated with the development of candidemia.

Conclusions.

Patients with CHD who have a high TISS score 1 week after PICU admission and patients who have received prolonged antibiotic therapy should be considered at high risk for candidemia. Our results suggest that shorter courses of antibiotic therapy, routine surveillance culture forCandidaspecies, and initiation of preemptive or empirical antifungal treatment could help in the clinical management of these patients.
Resistance and Responsibility
Authors: Cudd Ann E.
Published: June 2006

This chapter discusses strategies to resist oppression. It argues that resistance to oppression is possible and morally required, and demonstrates that for virtually all different forms of oppression there exist potentially successful means of resistance. All resistance begins with the recognition that there are serious injustices that can be addressed, and then must proceed to mitigate or at least protest the material and psychological harms. How legal theory might take a greater account of oppression within a liberal legal system is also discussed.
Fashioning Freedom
Authors: Cudd Ann E.
Published: June 2006

This chapter focuses on overcoming oppression, focusing on how women can liberate themselves. Topics discussed include the two senses of freedom, breaking the vicious cycle of oppression, two serious problems of social engineering, and enhancing the freedom of others.
Better Living: Toward a Cultural History of a Business Slogan
Authors: Shanken Andrew M.
Published: June 2006

This article traces the migration of the slogan “better living” from its inception in 1935 as an attempt to clean up the corporate image of Du Pont, through its dissemination into the building trades and architecture during and after World War II, and finally into urban planning in the postwar decades. These fields borrowed the phrase back and forth in their promotional literature in order to serve their own, often clashing agendas—one strand of the larger contest between the forces of free enterprise and those of centralized planning and reform. The essay aims to bring together aspects of business, architecture, and planning in order to explore the fertile cultural milieu these different fields shared in the middle decades of the twentieth century.
Human endogenous retrovirus-W envelope (syncytin) is expressed in both villous and extravillous trophoblast populations
Authors: Muir A. , Lever A. M. L. , Moffett A.
Published: June 2006

The placenta is unique amongst normal tissues in transcribing numerous different human endogenous retroviruses at high levels. In this study, RT-PCR and immunohistochemistry were used to investigate the expression of syncytin in human trophoblast. Syncytin transcripts were found in first-trimester trophoblast cells with both villous and extravillous phenotypes and also in the JAR and JEG-3 choriocarcinoma cell lines. Syncytin protein was detected in villous trophoblast and in all extravillous trophoblast subpopulations of first- and second-trimester placental tissues. It was also present in ectopic trophoblast from tubal implantations. This study confirms that syncytin is expressed widely by a variety of normal human trophoblast populations, as well as choriocarcinoma cell lines.
Interaction of severe acute respiratory syndrome-associated coronavirus with dendritic cells
Authors: Spiegel Martin , Schneider Kerstin , Weber Friedemann , Weidmann Manfred , Hufert Frank T.
Published: June 2006

Severe acute respiratory syndrome (SARS) of humans is caused by a novel coronavirus of zoonotic origin termed SARS-associated coronavirus (SARS-CoV). The virus induces severe injury of lung tissue, as well as lymphopenia and destruction of the architecture of lymphatic tissue by as-yet-unknown mechanisms. In this study, the interaction of SARS-CoV with dendritic cells (DCs), the key regulators of immune responses, was analysed. Monocyte-derived DCs were infected with SARS-CoV and analysed for viability, surface-marker expression and alpha interferon (IFN-α) induction. SARS-CoV infection was monitored by quantitative RT-PCR, immunofluorescence analysis and recovery experiments. SARS-CoV infected both immature and mature DCs, although replication efficiency was low. Immature DCs were activated by SARS-CoV infection and by UV-inactivated SARS-CoV. Infected DCs were still viable on day 6 post-infection, but major histocompatibility complex class I upregulation was missing, indicating that DC function was impaired. Additionally, SARS-CoV infection induced a delayed activation of IFN-α expression. Therefore, it is concluded that SARS-CoV has the ability to circumvent both the innate and the adaptive immune systems.
Inhibition of dengue virus replication by mycophenolic acid and ribavirin
Authors: Takhampunya Ratree , Ubol Sukathida , Houng Huo-Shu , Cameron Craig E. , Padmanabhan Radhakrishnan
Published: June 2006

Dengue viruses (DEN), mosquito-borne members of the familyFlaviviridae, are human pathogens of global significance. The effects of mycophenolic acid (MPA) and ribavirin (RBV) on DEN replication in monkey kidney (LLC-MK2) cells were examined. MPA (IC50=0.4±0.3 μM) and RBV (IC50=50.9±18 μM) inhibited DEN2 replication. Quantitative real-time RT-PCR of viral RNA and plaque assays of virions from DEN2-infected and MPA (10 μM)- and RBV (⩾200 μM)-treated cells showed a fivefold increase in defective viral RNA production by cells treated with each drug. Moreover, a dramatic reduction of intracellular viral replicase activity was seen byin vitroreplicase assays. Guanosine reversed the inhibition of these compounds, suggesting that one mode of antiviral action of MPA and RBV is by inhibition of inosine monophosphate dehydrogenase and thereby depletion of the intracellular GTP pool. In addition, RBV may act by competing with guanine-nucleotide precursors in viral RNA translation, replication and 5′ capping.
RNA signals in the 3′ terminus of the genome of Equine arteritis virus are required for viral RNA synthesis
Authors: Beerens Nancy , Snijder Eric J.
Published: June 2006

RNA virus genomes contain cis-acting sequences and structural elements involved in virus replication. Both full-length and subgenomic negative-strand RNA synthesis are initiated at the 3′ terminus of the positive-strand genomic RNA of Equine arteritis virus (EAV). To investigate the molecular mechanism of EAV RNA synthesis, the RNA secondary structure of the 3′-proximal region of the genome was analysed by chemical and enzymic probing. Based on the RNA secondary structure model derived from this analysis, several deletions were engineered in a full-length cDNA copy of the viral genome. Two RNA domains were identified that are essential for virus replication and most likely play a key role in viral RNA synthesis. The first domain, located directly upstream of the 3′ untranslated region (UTR) (nt 12610–12654 of the genome), is mainly single-stranded but contains one small stem–loop structure. The second domain is located within the 3′ UTR (nt 12661–12690) and folds into a prominent stem–loop structure with a large loop region. The location of this stem–loop structure near the 3′ terminus of the genome suggests that it may act as a recognition signal during the initiation of minus-strand RNA synthesis.
Transcriptional profiling of acute cytopathic murine hepatitis virus infection in fibroblast-like cells
Authors: Versteeg Gijs A. , Slobodskaya Olga , Spaan Willy J. M.
Published: June 2006

Understanding the orchestrated genome-wide cellular responses is critical for comprehending the early events of coronavirus infection. Microarray analysis was applied to assess changes in cellular expression profiles during different stages of two independent, highly controlled murine hepatitis virus (MHV) infectionsin vitro. Fibroblast-like L cells were infected at high multiplicity in order to study the direct effects of a synchronized lytic coronavirus infection. Total RNA was harvested from MHV- or mock-infected L cells at 3, 5 and 6 h post-infection and hybridized to Affymetrix microarrays representing approximately 12 500 murine genes and expressed sequences. The expression data were compared to their respective mock-infected controls. Quantitative RT-PCR of selected transcripts was used to validate the differential expression of transcripts and inter-experiment reproducibility of microarray analysis. It was concluded that MHV-A59 infection in fibroblast-like cells triggers very few transcriptional cellular responses in the first 3 h of infection. Later, after having established a productive infection, a chemokine response is induced together with other cellular changes associated with RNA and protein metabolism, cell cycle and apoptosis. Interferon responses are not triggered during infection, although the L cells can be readily stimulated to produce interferon by dsRNA, a known potent inducer of interferon. Possibly, the interferon response is actively counteracted by a virus-encoded antagonist as has been described previously for other RNA viruses.
Kinetics of African swine fever virus infection in Ornithodoros erraticus ticks
Authors: Basto Afonso P. , Nix Rebecca J. , Boinas Fernando , Mendes Susana , Silva Maria J. , Cartaxeiro Clara , Portugal Raquel S. , Leitão Alexandre , Dixon Linda K. , Martins Carlos
Published: June 2006

The kinetics of African swine fever virus (ASFV) infection in Ornithodoros erraticus ticks were investigated in specimens collected in the field at different times following an outbreak of the disease in Portugal in 1999 and in ticks infected experimentally with a virus isolated from a tick collected during this outbreak. In ticks collected from the field, initial screening for ASFV was carried out by PCR, followed by attempts to isolate the virus in macrophage cultures. Considering total numbers of ticks tested independently of developmental stages, ASFV DNA was detected in 42.3, 26.4 and 22.4 % of specimens collected at weeks 0, 32 and 63 following the outbreak, respectively. Although virus was not isolated from most of these ticks, the proportion of isolations from large nymphs and adults increased between weeks 0 and 32 from 2 to 9 % and from 5 to 11.5 %, respectively. These results, together with the higher virus titres at week 32, suggest that virus replication occurred. In contrast, virus isolations from small nymphs decreased over this period, from 5 to 1.3 %. At week 63, infection rates decreased for all stages. Experimental infections showed the occurrence of virus replication within 4 weeks post-feeding and maintenance of high titres in almost 100 % of ticks until 20 weeks post-infection. At weeks 41 and 61, a drop in virus titres and infection rates was observed. Relevant to the understanding of African swine fever epidemiology, our results show that ASFV replicates and persists in O. erraticus, but a viral clearance occurs at later times in both natural and experimental infections.
Characterization of a highly pathogenic H5N1 influenza virus derived from bar-headed geese in China
Authors: Zhou Ji-Yong , Shen Hui-Gang , Chen Hong-Xun , Tong Guang-Zhi , Liao Ming , Yang Han-Chun , Liu Jian-Xin
Published: June 2006

Influenza A viruses are usually non-pathogenic in wild aquatic birds, their natural reservoir. However, from May to July 2005, at Qinghai Lake in China, an unprecedented outbreak of highly pathogenic H5N1 avian influenza virus caused the death of thousands of wild migratory waterbirds. Herein, H5N1 influenza virus from bar-headed geese collected during the outbreak was characterized. Genomic analysis showed that A/Bar-headed Goose/Qinghai/0510/05 (Bh H5N1 virus) is a reassortant virus. Amino acid residue (lysine) at position 627 in the PB2 gene of the Bh H5N1 virus was the same as that of the human H5N1 virus (A/HK/483/97) and different from that of H5N1 avian influenza viruses deposited in GenBank. Antigenic analysis showed that significant antigenic variation has occurred in the Bh H5N1 virus. The Bh H5N1 virus induced systemic infections and caused 100 % mortality in chickens and mice, and 80 % mortality in ducks and geese. Bh H5N1 virus titres were higher in multiple organs of chickens, ducks and geese than in mice, and caused more severe histological lesions in chickens, ducks and mice than in geese. These results support the need to pay close attention and create control programmes to prevent the transmission of highly pathogenic avian influenza virus from wild migratory waterbirds into domestic chickens, ducks, geese and mammalian hosts.
Analysis of the viability of coat-protein hybrids between Cucumber mosaic virus and Tomato aspermy virus
Authors: Llamas Susana , Moreno Ignacio M. , García-Arenal Fernando
Published: June 2006

Coat-protein (CP) hybrids between Cucumber mosaic virus (CMV) and Tomato aspermy virus (TAV) were engineered to analyse reported CP-associated differences between these viruses. CP portions delimited by aa 1–59, 60–148 and 149–219 were exchanged in all possible combinations within TAV RNA3. The seven possible chimeras were able to replicate in tobacco protoplasts to similar levels, but only those having residues 1–59 or 60–148 from CMV were infectious to tobacco plants, a common host for CMV and TAV, and formed stable particles. When most of the movement protein (MP) of TAV was substituted for that of CMV, infectivity of CP hybrids did not vary. No hybrid was able to infect cucumber plants, a host for CMV and not for TAV. Need for MP–CP compatibility could explain these results, but shows that MP–CP compatibility conditions the use of CP chimeras to map CP-associated differences between CMV and TAV.