bluuebunny/crossref_metadata_2025 huggingface dataset:
A biosynthetic pathway for anandamide
Authors: Liu Jie , Wang Lei , Harvey-White Judith , Osei-Hyiaman Douglas , Razdan Raj , Gong Qian , Chan Andrew C. , Zhou Zhifeng , Huang Bill X. , Kim Hee-Yong , Kunos George
Published: August 2006

The endocannabinoid arachidonoyl ethanolamine (anandamide) is a lipid transmitter synthesized and released “on demand” by neurons in the brain. Anandamide is also generated by macrophages where its endotoxin (LPS)-induced synthesis has been implicated in the hypotension of septic shock and advanced liver cirrhosis. Anandamide can be generated from its membrane precursor,
N
-arachidonoyl phosphatidylethanolamine (NAPE) through cleavage by a phospholipase D (NAPE–PLD). Here we document a biosynthetic pathway for anandamide in mouse brain and RAW264.7 macrophages that involves the phospholipase C (PLC)-catalyzed cleavage of NAPE to generate a lipid, phosphoanandamide, which is subsequently dephosphorylated by phosphatases, including PTPN22, previously described as a protein tyrosine phosphatase. Bacterial endotoxin (LPS)-induced synthesis of anandamide in macrophages is mediated exclusively by the PLC/phosphatase pathway, which is up-regulated by LPS, whereas NAPE–PLD is down-regulated by LPS and functions as a salvage pathway of anandamide synthesis when the PLC/phosphatase pathway is compromised. Both PTPN22 and endocannabinoids have been implicated in autoimmune diseases, suggesting that the PLC/phosphatase pathway of anandamide synthesis may be a pharmacotherapeutic target.
All Change on the Media Front
Authors: Gardel Uffe
Published: August 2006

THE PROLIFERATION OF FREE SHEETS CHALLENGES THE TRADITIONAL NEWSPAPER MONOPOLY IN DENMARK
Facing Up to the Big Red Apple
Authors: Pope Nicole
Published: August 2006

WRITERS AND JOURNALISTS ARE ONCE AGAIN AT THE SHARP END OF THE LAW AS A NATIONALIST BACKLASH THREATENS TO ROLL BACK TURKEY’S PROGRESS TOWARDS THE EU — AND THE MEDIA IS AS MUCH PARTICIPANT AS RECORDER
Rukhnamania: Fantasies of a Dictator
Authors: Takhbatullin Farid
Published: August 2006

Following immense international pressure, Turkmen satirist Farid Takhbatullin was granted amnesty from three years in prison in 2003. His work on the environment brought him head-to-head with President Saparmyrat Niyazov and he felt he had no future in his own country. From his new home in western Europe, he follows events in Turkmenistan closely and publishes a human rights bulletin online. He plans to launch Central Asia’s first satirical website this year.
Antique Attitudes
Authors: Islam Shada
Published: August 2006

THE EURO-MEDIA HAS YET TO CATCH UP WITH THE CHANGING REALITY OF A NEW AND NOT VERY BRAVE EUROPE
And Now for Something Completely Different?
Authors: Maryniak Irena
Published: August 2006

POLISH JOURNALISTS ARE ADEPT AT SELF-CENSORSHIP. NOT THAT THEY WOULD CALL IT THAT; MORE A QUESTION OF NOT WASHING DIRTY LINEN IN EURO-WATERS AND KEEPING UP THE SELF IMAGE
Beyond Knowledge to Wisdom in International Business Strategy
Authors: McKenna Bernard , Rooney David , Liesch Peter W.
Published: August 2006

A wisdom approach is advanced as a means of breaking the mimesis of institutional isomorphism that is observed both in the practice and scholarship of orthodox business management. Nine principles of wisdom derived from the Aristotelian tradition and contemporary psychological research are provided. These are then tested in an international business case study. This analysis supports the case that, while rational judgment is necessary, wise management also requires a capacity for counter‐intuition, vision, and humanity. It also shows that wisdom in management must ultimately be practical. When practised by wise managers, such wisdom can opportunistically circumvent the discursive limitations imposed by current orthodoxy in the turbulent, ephemeral conditions of international business and its management.
Enhancement of the Cytotoxicity of Liposomal Ricin by the Carboxylic Ionophore Monensin and the Lysosomotropic Amine NH4Cl in Chinese Hamster Ovary Cells
Authors: Bharadwaj Seemha , Rathore Shailendra Singh , Ghosh Prahlad C.
Published: August 2006

Ricin was encapsulated in negatively charged liposomes and its effect on the cytotoxicity was compared with native ricin in Chinese hamster ovarian (CHO) cells. The cytotoxicity of ricin, as measured by a marker protein synthesis (incorporation of 3H-leucine), was reduced markedly (300-fold) following encapsulation in liposomes. Lactose, a potent inhibitor of ricin cytotoxicity, had no effect on the binding, internalization, and cytotoxicity of liposomal ricin, indicating that liposomal ricin enter into mammalian cells by an alternative route, bypassing galactose-mediated endocytic pathway. Both monensin (a carboxylic ionophore) and NH4Cl (a lysosomotropic amine) markedly enhances the cytotoxicity of liposomal ricin, indicating endocytotic uptake of liposomal ricin. The degree of potentiation of the cytotoxicity of liposomal ricin by both monensin and NH4Cl was significantly higher (441- and 51-fold) as compared to native ricin (62.5- and 12.5-fold). The extent of exocytosis of free ricin was found to be much higher as compared to liposomal ricin; on the other hand, the extent of degradation of free and liposomal ricin was identical. Consequently, the intracellular level of liposomal ricin was increased to 3.5-fold. This higher level of intracellular liposomal ricin may allow more efficient ricin A-chain release into the cytosol under the influence of NH4Cl and monensin. Monensin-induced potentiation of liposomal ricin was prevented by brefeldin A, indicating that in the presence of monensin, the liposomal ricin was efficiently routed through the Golgi apparatus en route to the cytosol. Thus, liposomal ricin in combination with monensin may have potential application for selective elimination of malignant cells.
Toxicity Studies of Blockal, a Dietary Supplement Containing Phase 2 Starch Neutralizer (Phase 2), a Standardized Extract of the Common White Kidney Bean (Phaseolus vulgaris)
Authors: Chokshi Dilip
Published: August 2006

The number of available dietary supplements containing “starch blockers” intended for weight loss has risen dramatically in recent years. These supplements are believed to reduce carbohydrate-derived calories by interfering with α-amylase, the digestive enzyme responsible for conversion of complex carbohydrates to simple absorbable sugars. The present paper reports the findings of single- and multiple-dose (4-week) oral toxicity studies in rats of the marketed dietary supplement Blockal. Blockal contains as its main ingredient Phase 2 Starch Neutralizer (Phase 2 or Phaseolamin 2250), a standardized extract derived from the common white kidney bean ( Phaseolus vulgaris) that has been shown to have α-amylase-inhibiting activity. The Blockal acute oral LD50 exceeded the highest dose tested (3 g/kg body weight [bw]), which provided a single dose of 1668 mg/kg bw of Phase 2 white kidney bean extract. The no-observed-effect level (NOEL) seen in the 4-week study was equivalent to the highest Blockal dose tested (2 g/kg bw/day), which provided 1112 mg/kg/day of Phase 2 white kidney bean extract. The results of these studies support and are consistent with the safety of the marketed dietary supplement Blockal, and indirectly, the safety of its main ingredient, Phase 2 Starch Neutralizer (Phase 2 or Phaseolamin 2250), a standardized extract derived from the common white kidney bean.
The Reactivating and Therapeutic Efficacy of Oximes to Counteract Russian VX Poisonings
Authors: Kassa Jiri , Jun Daniel , Kuca Kamil
Published: August 2006

Russian VX ( O-isobutyl- S-(2-diethylaminoethyl)methylphosphonothioate) is the structural analogue of VX agent. It differs from VX agent ( O-ethyl- S-(2-diisopropylaminoethyl) methylphosphonothioate) by two alkyl groups. The potency of currently available oximes (pralidoxime, obidoxime, HI-6) to reactivate Russian VX–inhibited acetylcholinesterase and to eliminate Russian VX–induced acute toxic effects was evaluated using in vivo methods. In vivo determined percentage of reactivation of Russian VX–inhibited blood and brain acetylcholinesterase in poisoned rats shows that HI-6 seems to be the most efficacious reactivator of Russian VX–inhibited acetylcholinesterase among currently used oximes in the peripheral compartment, whereas no difference between reactivating efficacy of all tested oximes was observed in the central compartment. The oxime HI-6 was also found to be the most efficacious oxime in the elimination of acute lethal toxic effects in Russian VX–poisoned mice among all studied oximes. Thus, the oxime HI-6 seems to be the most suitable oxime for the antidotal treatment of acute poisonings with Russian VX as in the case of VX, sarin, cyclosarin, and soman poisonings.
DOCK2 is a Rac activator that regulates motility and polarity during neutrophil chemotaxis
Authors: Kunisaki Yuya , Nishikimi Akihiko , Tanaka Yoshihiko , Takii Ryosuke , Noda Mayuko , Inayoshi Ayumi , Watanabe Ken-ichi , Sanematsu Fumiyuki , Sasazuki Takehiko , Sasaki Takehiko , Fukui Yoshinori
Published: August 2006

Neutrophils are highly motile leukocytes, and they play important roles in the innate immune response to invading pathogens. Neutrophil chemotaxis requires Rac activation, yet the Rac activators functioning downstream of chemoattractant receptors remain to be determined. We show that DOCK2, which is a mammalian homologue of Caenorhabditis elegans CED-5 and Drosophila melanogaster Myoblast City, regulates motility and polarity during neutrophil chemotaxis. Although DOCK2-deficient neutrophils moved toward the chemoattractant source, they exhibited abnormal migratory behavior with a marked reduction in translocation speed. In DOCK2-deficient neutrophils, chemoattractant-induced activation of both Rac1 and Rac2 were severely impaired, resulting in the loss of polarized accumulation of F-actin and phosphatidylinositol 3,4,5-triphosphate (PIP3) at the leading edge. On the other hand, we found that DOCK2 associates with PIP3 and translocates to the leading edge of chemotaxing neutrophils in a phosphatidylinositol 3-kinase (PI3K)–dependent manner. These results indicate that during neutrophil chemotaxis DOCK2 regulates leading edge formation through PIP3-dependent membrane translocation and Rac activation.
Integrin-mediated adhesion regulates membrane order
Authors: Gaus Katharina , Le Lay Soazig , Balasubramanian Nagaraj , Schwartz Martin A.
Published: August 2006

The properties of cholesterol-dependent domains (lipid rafts) in cell membranes have been controversial. Because integrin-mediated cell adhesion and caveolin both regulate trafficking of raft components, we investigated the effects of adhesion and caveolin on membrane order. The fluorescent probe Laurdan and two-photon microscopy revealed that focal adhesions are highly ordered; in fact, they are more ordered than caveolae or domains that stain with cholera toxin subunit B (CtxB). Membrane order at focal adhesion depends partly on phosphorylation of caveolin1 at Tyr14, which localizes to focal adhesions. Detachment of cells from the substratum triggers a rapid, caveolin-independent decrease in membrane order, followed by a slower, caveolin-dependent decrease that correlates with internalization of CtxB-stained domains. Endocytosed CtxB domains also become more fluid. Thus, membrane order is highly dependent on caveolae and focal adhesions. These results show that lipid raft properties are conferred by assembly of specific protein complexes. The ordered state within focal adhesions may have important consequences for signaling at these sites.
Identification of Tam41 maintaining integrity of the TIM23 protein translocator complex in mitochondria
Authors: Tamura Yasushi , Harada Yoshihiro , Yamano Koji , Watanabe Kazuaki , Ishikawa Daigo , Ohshima Chié , Nishikawa Shuh-ichi , Yamamoto Hayashi , Endo Toshiya
Published: August 2006

Newly synthesized mitochondrial proteins are imported into mitochondria with the aid of protein translocator complexes in the outer and inner mitochondrial membranes. We report the identification of yeast Tam41, a new member of mitochondrial protein translocator systems. Tam41 is a peripheral inner mitochondrial membrane protein facing the matrix. Disruption of the TAM41 gene led to temperature-sensitive growth of yeast cells and resulted in defects in protein import via the TIM23 translocator complex at elevated temperature both in vivo and in vitro. Although Tam41 is not a constituent of the TIM23 complex, depletion of Tam41 led to a decreased molecular size of the TIM23 complex and partial aggregation of Pam18 and -16. Import of Pam16 into mitochondria without Tam41 was retarded, and the imported Pam16 formed aggregates in vitro. These results suggest that Tam41 facilitates mitochondrial protein import by maintaining the functional integrity of the TIM23 protein translocator complex from the matrix side of the inner membrane.
Muscle aging is associated with compromised Ca2+ spark signaling and segregated intracellular Ca2+ release
Authors: Weisleder Noah , Brotto Marco , Komazaki Shinji , Pan Zui , Zhao Xiaoli , Nosek Thomas , Parness Jerome , Takeshima Hiroshi , Ma Jianjie
Published: August 2006

Reduced homeostatic capacity for intracellular Ca2+ ([Ca2+]i) movement may underlie the progression of sarcopenia and contractile dysfunction during muscle aging. We report two alterations to Ca2+ homeostasis in skeletal muscle that are associated with aging. Ca2+ sparks, which are the elemental units of Ca2+ release from sarcoplasmic reticulum, are silent under resting conditions in young muscle, yet activate in a dynamic manner upon deformation of membrane structures. The dynamic nature of Ca2+ sparks appears to be lost in aged skeletal muscle. Using repetitive voltage stimulation on isolated muscle preparations, we identify a segregated [Ca2+]i reserve that uncouples from the normal excitation–contraction process in aged skeletal muscle. Similar phenotypes are observed in adolescent muscle null for a synaptophysin-family protein named mitsugumin-29 (MG29) that is involved in maintenance of muscle membrane ultrastructure and Ca2+ signaling. This finding, coupled with decreased expression of MG29 in aged skeletal muscle, suggests that MG29 expression is important in maintaining skeletal muscle Ca2+ homeostasis during aging.
Autoinhibition regulates cellular localization and actin assembly activity of the diaphanous-related formins FRLα and mDia1
Authors: Seth Abhinav , Otomo Chinatsu , Rosen Michael K.
Published: August 2006

Diaphanous-related formins (DRFs) are key regulators of actin cytoskeletal dynamics whose in vitro actin assembly activities are thought to be regulated by autoinhibition. However, the in vivo consequences of autoinhibition and the involvement of DRFs in specific biological processes are not well understood. In this study, we show that in the DRFs FRLα (formin-related gene in leukocytes α) and mouse diaphanous 1, autoinhibition regulates a novel membrane localization activity in vivo as well as actin assembly activity in vitro. In FRLα, the Rho family guanosine triphosphatase Cdc42 relieves the autoinhibition of both membrane localization and biochemical actin assembly activities. FRLα is required for efficient Fc-γ receptor–mediated phagocytosis and is recruited to the phagocytic cup by Cdc42. These results suggest that mutual autoinhibition of biochemical activity and cellular localization may be a general regulatory principle for DRFs and demonstrate a novel role for formins in immune function.
Inhibition of centrosome protein assembly leads to p53-dependent exit from the cell cycle
Authors: Srsen Vlastimil , Gnadt Nicole , Dammermann Alexander , Merdes Andreas
Published: August 2006

Previous evidence has indicated that an intact centrosome is essential for cell cycle progress and that elimination of the centrosome or depletion of individual centrosome proteins prevents the entry into S phase. To investigate the molecular mechanisms of centrosome-dependent cell cycle progress, we performed RNA silencing experiments of two centrosome-associated proteins, pericentriolar material 1 (PCM-1) and pericentrin, in primary human fibroblasts. We found that cells depleted of PCM-1 or pericentrin show lower levels of markers for S phase and cell proliferation, including cyclin A, Ki-67, proliferating cell nuclear antigen, minichromosome maintenance deficient 3, and phosphorylated retinoblastoma protein. Also, the percentage of cells undergoing DNA replication was reduced by >50%. At the same time, levels of p53 and p21 increased in these cells, and cells were predisposed to undergo senescence. Conversely, depletion of centrosome proteins in cells lacking p53 did not cause any cell cycle arrest. Inhibition of p38 mitogen-activated protein kinase rescued cell cycle activity after centrosome protein depletion, indicating that p53 is activated by the p38 stress pathway.
pH-regulated Slo3 K+ Channels: Properties of Unitary Currents
Authors: Zhang Xue , Zeng Xuhui , Xia Xiao-Ming , Lingle Christopher J.
Published: August 2006

Here we have examined the voltage and pH dependence of unitary Slo3 channels and used analysis of current variance to define Slo3 unitary current properties over a broader range of voltages. Despite complexity in Slo3 channel openings that precludes simple definition of the unitary conductance, average current through single Slo3 channels varies linearly with voltage at positive activation potentials. Furthermore, the average Slo3 unitary current at a given activation potential does not change with pH. Consistent with macroscopic conductance estimates, the apparent open probability of Slo3 channel exhibits a pH-dependent maximum, with limiting values around 0.3 at the most elevated pH and voltage. Estimates of Slo3 conductance at negative potentials support a weaker intrinsic voltage dependence of gating than is observed for Slo1. For the pH-regulated Slo3 K+ channel, the dependence of macroscopic conductance on pH suggests that the pH-sensitive mechanism regulates gating in an allosteric manner qualitatively similar to regulation of Slo1 by Ca2+. Together, the results support the view that the regulation of macroscopic Slo3 currents by pH reflects regulation of gating equilibria, and not a direct effect of pH on ion permeation. Specifically, both voltage and pH regulate a closed–open conformational change in a largely independent fashion.
Odorant Inhibition of the Olfactory Cyclic Nucleotide-gated Channel with a Native Molecular Assembly
Authors: Chen Tsung-Yu , Takeuchi Hiroko , Kurahashi Takashi
Published: August 2006

Human olfaction comprises the opposing actions of excitation and inhibition triggered by odorant molecules. In olfactory receptor neurons, odorant molecules not only trigger a G-protein–coupled signaling cascade but also generate various mechanisms to fine tune the odorant-induced current, including a low-selective odorant inhibition of the olfactory signal. This wide-range olfactory inhibition has been suggested to be at the level of ion channels, but definitive evidence is not available. Here, we report that the cyclic nucleotide-gated (CNG) cation channel, which is a key element that converts odorant stimuli into electrical signals, is inhibited by structurally unrelated odorants, consistent with the expression of wide-range olfactory inhibition. Interestingly, the inhibitory effect was small in the homo-oligomeric CNG channel composed only of the principal channel subunit, CNGA2, but became larger in channels consisting of multiple types of subunits. However, even in the channel containing all native subunits, the potency of the suppression on the cloned CNG channel appeared to be smaller than that previously shown in native olfactory neurons. Nonetheless, our results further showed that odorant suppressions are small in native neurons if the subsequent molecular steps mediated by Ca2+ are removed. Thus, the present work also suggests that CNG channels switch on and off the olfactory signaling pathway, and that the on and off signals may both be amplified by the subsequent olfactory signaling steps.
Single Cl− Channels Activated by Ca2+ in Drosophila S2 Cells Are Mediated By Bestrophins
Authors: Chien Li-Ting , Zhang Zhi-Ren , Hartzell H. Criss
Published: August 2006

Mutations in human bestrophin-1 (VMD2) are genetically linked to several forms of retinal degeneration but the underlying mechanisms are unknown. Bestrophin-1 (hBest1) has been proposed to be a Cl− channel involved in ion and fluid transport by the retinal pigment epithelium (RPE). To date, however, bestrophin currents have only been described in overexpression systems and not in any native cells. To test whether bestrophins function as Ca2+-activated Cl− (CaC) channels physiologically, we used interfering RNA (RNAi) in the Drosophila S2 cell line. S2 cells express four bestrophins (dbest1–4) and have an endogenous CaC current. The CaC current is abolished by several RNAi constructs to dbest1 and dbest2, but not dbest3 or dbest4. The endogenous CaC current was mimicked by expression of dbest1 in HEK cells, and the rectification and relative permeability of the current were altered by replacing F81 with cysteine. Single channel analysis of the S2 bestrophin currents revealed an ∼2-pS single channel with fast gating kinetics and linear current–voltage relationship. A similar channel was observed in CHO cells transfected with dbest1, but no such channel was seen in S2 cells treated with RNAi to dbest1. This provides definitive evidence that bestrophins are components of native CaC channels at the plasma membrane.
Bio3d: an R package for the comparative analysis of protein structures
Authors: Grant Barry J. , Rodrigues Ana P. C. , ElSawy Karim M. , McCammon J. Andrew , Caves Leo S. D.
Published: August 2006

Summary: An automated procedure for the analysis of homologous protein structures has been developed. The method facilitates the characterization of internal conformational differences and inter-conformer relationships and provides a framework for the analysis of protein structural evolution. The method is implemented in bio3d, an R package for the exploratory analysis of structure and sequence data.

Availability: The bio3d package is distributed with full source code as a platform-independent R package under a GPL2 license from:

Contact:  bgrant@mccammon.ucsd.edu
Model-based boosting in high dimensions
Authors: Hothorn Torsten , Bühlmann Peter
Published: August 2006

Summary: The R add-on package mboost implements functional gradient descent algorithms (boosting) for optimizing general loss functions utilizing componentwise least squares, either of parametric linear form or smoothing splines, or regression trees as base learners for fitting generalized linear, additive and interaction models to potentially high-dimensional data.

Availability: Package mboost is available from the Comprehensive R Archive Network () under the terms of the General Public Licence (GPL).

Contact:  Torsten.Hothorn@R-project.org
The folding mechanism of collagen‐like model peptides explored through detailed molecular simulations
Authors: Stultz Collin M.
Published: August 2006

Collagen has a unique folding mechanism that begins with the formation of a triple‐helical structure near its C terminus followed by propagation of this structure to the N terminus. To elucidate factors that affect the folding of collagen, we explored the folding pathway of collagen‐like model peptides using detailed molecular simulations with explicit solvent. Using biased molecular dynamics we examined the latter stages of folding of a peptide model of native collagen, (Pro‐Hyp‐Gly)10, and a peptide that models a Gly → Ser mutation found in several forms of osteogenesis imperfecta, (Pro‐Hyp‐Gly)3‐Pro‐Hyp‐Ser‐(Pro‐Hyp‐Gly)6. Starting from an unfolded state that contains a C‐terminal nucleated trimer, (Pro‐Hyp‐Gly)10 folds to a structure where two of the three chains associate through water‐mediated hydrogen bonds and the third is relatively separated from this dimer. Calculated free‐energy profiles for folding from this intermediate to the final triple‐helical structure suggest that further folding occurs at a rate of approximately one Pro‐Hyp‐Gly triplet per msec. In contrast, after 6 nsec of biased dynamics, the region N‐terminal to the Ser residue in (Pro‐Hyp‐Gly)3‐Pro‐Hyp‐Ser‐(Pro‐Hyp‐Gly)6 folds to a structure where the three chains form close contacts near the N terminus, away from the mutation site. Further folding to an ideal triple‐helical structure at the site of the mutation is unfavorable as the free energy of a triple‐helical conformation at this position is more than 20 kcal/mol higher than that of a structure with unassociated chains. These data provide insights into the folding pathway of native collagen and the events underlying the formation of misfolded structures.
Identification of an alcohol binding site in the first cysteine‐rich domain of protein kinase C δ
Authors: Das Joydip , Zhou Xiaojuan , Miller Keith W.
Published: August 2006

Protein kinase C (PKC) is an important signal transduction protein whose cysteine‐rich regulatory domain C1 has been proposed to interact with general anesthetics in both of its diacylglycerol/phorbol ester–binding subdomains, the tandem repeats C1A and C1B. Previously, we identified an allosteric binding site on one of the two cysteine‐rich domains, PKCδ C1B. To test the hypothesis that there is an additional anesthetic site on the other cysteine‐rich subdomain, C1A, we subcloned, expressed in Escherichia coli, purified, and characterized mouse PKCδ C1A. Octanol and butanol both quenched the intrinsic fluorescence of PKCδ C1A in a saturable manner, suggesting the presence of a binding site. To locate this site, PKCδ C1A was photolabeled with three diazirine‐containing alkanols, 3‐azioctanol, 7‐azioctanol, and 3‐azibutanol. Mass spectrometry revealed that at low concentrations all three photoincorporated into PKCδ C1A with a stoichiometry of 1:1 in the labeled fraction, but higher stoichiometries occurred at higher concentrations, particularly with azibutanol. Photocomplexes of PKCδ C1A with azioctanols were separated from the unlabeled protein by HPLC, reduced, alkylated, digested with trypsin, and sequenced by mass spectrometry. All the azioctanols photolabeled PKCδ C1A at residue Tyr‐29, corresponding to Tyr‐187 of the full‐length PKCδ, and at a neighboring residue, Lys‐40, suggesting there is an alcohol site in this vicinity. In addition, Glu‐2 was photolabeled more efficiently by 3‐azibutanol than by the azioctanols, suggesting the existence of a second, smaller site.
The structure of GDP‐4‐keto‐6‐deoxy‐d‐mannose‐3‐dehydratase: A unique coenzyme B6‐dependent enzyme
Authors: Cook Paul D. , Thoden James B. , Holden Hazel M.
Published: August 2006

l‐Colitose is a 3,6‐dideoxysugar found in the O‐antigens of some Gram‐negative bacteria such as Escherichia coli and in marine bacteria such as Pseudoalteromonas tetraodonis. The focus of this investigation, GDP‐4‐keto‐6‐deoxy‐d‐mannose‐3‐dehydratase, catalyzes the third step in colitose production, which is the removal of the hydroxyl group at C3′ of GDP‐4‐keto‐6‐deoxymannose. It is an especially intriguing PLP‐dependent enzyme in that it acts as both a transaminase and a dehydratase. Here we present the first X‐ray structure of this enzyme isolated from E. coli Strain 5a, type O55:H7. The two subunits of the protein form a tight dimer with a buried surface area of ∼5000 Å2. This is a characteristic feature of the aspartate aminotransferase superfamily. Although the PLP‐binding pocket is formed primarily by one subunit, there is a loop, delineated by Phe 240 to Glu 253 in the second subunit, that completes the active site architecture. The hydrated form of PLP was observed in one of the enzyme/cofactor complexes described here. Amino acid residues involved in anchoring the cofactor to the protein include Gly 56, Ser 57, Asp 159, Glu 162, and Ser 183 from one subunit and Asn 248 from the second monomer. In the second enzyme/cofactor complex reported, a glutamate ketimine intermediate was found trapped in the active site. Taken together, these two structures, along with previously reported biochemical data, support the role of His 188 as the active site base required for catalysis.
Polymorphism at the β3‐adrenergic receptor (ADRB3) locus of Merino sheep and its association with lamb mortality
Authors: Forrest R. H. , Hickford J. G. H. , Wynyard J. , Merrick N. , Hogan A. , Frampton C.
Published: August 2006

β
3‐adrenergic receptors are predominantly found on the surface of adipocytes and are major mediators of the lipolytic and thermogenic effects of high catecholamine concentrations. Recently, variation in the ovine β3‐adrenergic receptor (ADRB3) gene has been reported to be associated with lamb survival. In this study, polymerase chain reaction‐single strand conformational polymorphism analysis of part of the ADRB3 intron was used to genotype 4488 Merino lambs born at 10 farms throughout the South Island of New Zealand. Univariate and multivariate odds ratios for each allele revealed a significant association of the E allele with cdd survival and of the D allele with mortality. This variation at the ADRB3 locus may assist in the genetic selection for survival in Merino sheep.
Population pharmacokinetics of darbepoetin alfa in healthy subjects
Authors: Agoram Balaji , Sutjandra Liviawati , Sullivan John T.
Published: August 2006

Aim

To develop and evaluate a population pharmacokinetic (PK) model of the long‐acting erythropoiesis‐stimulating protein, darbepoetin alfa in healthy subjects.

Methods

PK profiles were obtained from 140 healthy subjects receiving single intravenous and/or single or multiple subcutaneous doses of darbepoetin alfa (0.75–8.0 µg kg−1, or either 80 or 500 µg). Data were analysed by a nonlinear mixed‐effects modelling approach using NONMEM software. Influential covariates were identified by covariate analysis emphasizing parameter estimates and their confidence intervals, rather than stepwise hypothesis testing. The model was evaluated by comparing simulated profiles (obtained using the covariate model) to the observed profiles in a test dataset.

Results

The population PK model, including first‐order absorption, two‐compartment disposition and first‐order elimination, provided a good description of data. Modelling indicated that for a 70‐kg human, the observed nearly twofold disproportionate dose–exposure relationship at the 8.0 µg kg−1‐dose relative to the 0.75 µg kg−1‐dose may reflect changing relative bioavailability, which increased from ∼ 48% at 0.75 µg kg−1 to 78% at 8.0 µg kg−1. The covariate analysis showed that increasing body weight may be related to increasing clearance and central compartment volume, and that the absorption rate constant decreased with increasing age. The full covariate model performed adequately in a fixed‐effects prediction test against an external dataset.

Conclusion

The developed population PK model describes the inter‐ and intraindividual variability in darbepoetin alfa PK. The model is a suitable tool for predicting the PK response of darbepoetin alfa using clinically untested dosing regimens.
Risk of hospitalization for angio‐oedema among users of newer COX‐2 selective inhibitors and other nonsteroidal anti‐inflammatory drugs
Authors: Downing Amy , Jacobsen Jacob , Sorensen Henrik T. , McLaughlin Joseph K. , Johnsen Soren P.
Published: August 2006

What is already known about this subject

• There is some evidence that the risk of cutaneous reactions is lower in patients taking newer cyclooxygenase (COX)‐2 selective inhibitors than in users of other nonsteroidal anti‐inflammatory drugs (NSAIDs).

• However, the data are inconclusive and formal epidemiological evidence is lacking.

What this study adds

• This population‐based case–control study found no elevated risk for angio‐oedema amongst users of newer COX‐2 selective inhibitors, whilst users of other NSAIDS were shown to have an increased risk.

• Our data support the hypothesis that newer COX‐2 selective inhibitors are safe in relation to angio‐oedema.

• However, given other current health concerns related to these drugs, their use should continue to be carefully monitored.

Aim

To examine the risk of angio‐oedema among users of the newer cyclooxygenase (COX)‐2 selective inhibitors celecoxib and rofecoxib and other non‐aspirin nonsteroidal anti‐inflammatory drugs (NSAIDs) in a population‐based case–control study.

Methods

Cases of angio‐oedema were identified from hospital discharge registries from three Danish counties between 1 January 2000 and 31 December 2003 (n = 377) and 10 matched population controls per case were selected from the Civil Registration System (n = 3747). Data on newer COX‐2 selective inhibitor and other NSAID use (current and former) were obtained from prescription databases. Data on potential confounding factors were also collected. Conditional logistic regression was used to compute relative risks for angio‐oedema according to drug exposure.

Results

The crude relative risks for the newer COX‐2 selective inhibitors were higher than those for other NSAIDs. After adjustment for confounding, the relative risk for current use of newer COX‐2 selective inhibitors was 0.96 [95% confidence interval (CI) 0.46, 2.03], whereas the risk for other NSAIDs was 1.77 (95% CI 1.23, 2.58).

Conclusion

Our data support the hypothesis that newer COX‐2 selective inhibitors are safe in relation to angio‐oedema. However, given other current health concerns related to these drugs, their use should continue to be carefully monitored.
Yersinia enterocolitica infection does not confer an increased risk of thyroid antibodies: evidence from a Danish twin study
Authors: Hansen P S , Wenzel B E , Brix T H , Hegedüs L
Published: August 2006

Understanding of the aetiological basis of thyroid autoimmunity may be gained by studying the early stages of the disease process. We aimed to (1) investigate the relationship between thyroid antibody status and Yersinia enterocolitica (YE) infection in euthyroid subjects and (2) explore the relative importance of genetic and environmental risk factors in the acquisition of YE infection. The association between thyroid antibody status and YE infection was explored using a case–control design. Furthermore, thyroid antibody-positive twins were compared with their thyroid antibody-negative co-twin. In 468 twins, IgA and IgG antibodies to virulence-associated outer-membrane proteins (YOPs) of YE were measured. Of these, 147 were thyroid antibody-positive (cases). A total of 147 age- and gender-matched twins were chosen as controls. The prevalence of YOP antibodies was lower among thyroid antibody-positive individuals than among controls. Yersinia infection was not associated with a positive thyroid antibody status: the odds ratio (with 95% CI) for YOP IgA-ab was 0·66 (0·42–1·05), P = 0·078 and for YOP IgG-ab it was 0·95 (0·60–1·50), P = 0·816. Within discordant twin pairs, the thyroid antibody-positive twin did not have an increased risk of Yersinia infection compared to the thyroid antibody-negative co-twin [odds ratio: YOP IgA-Ab: 0·94 (0·49–1·83), P = 0·866, and YOP IgG-Ab: 1·35 (0·72–2·53), P = 0·345]; 41% (95% CI 10–67% of the liability of being YOP antibody-positive was due to genetic effects. In conclusion, Yersinia infection does not confer an increased risk of thyroid antibodies. The genetic contribution in the acquisition of Yersinia infection is modest.
Relationships between the density and diversity of floral resources and flower visitor activity in a temperate grassland community
Authors: HEGLAND STEIN J. , BOEKE LUCAS
Published: August 2006

Abstract 1. Does the diversity and abundance of one trophic level affect another? Several studies at the landscape level have found a positive relationship between the diversity of floral resources and the diversity and abundance of pollinators. However, little is known about the relationship between these trophic levels on a smaller spatial scale, and the importance of blossom density relative to plant species richness in predicting abundance and richness of different flower visitor groups.

2. This study used a small‐scale approach to investigate how, and if, the diversity and abundance of floral resources in study plots affected the visitation activity of different flower visitor groups. During 201 observation periods between late May and mid‐August 2003, 3682 visits were observed. Bumblebees (60%), muscoids (17%), syrphids (9%), and beetles (5%) were the most abundant flower visitors.

3. Regression analysis was used to investigate the relationship between blossom density and plant species richness with visitation activity, including the probability of presence in plots, the visits within plots, and the visitor richness of the most abundant pollinator groups.

4. The activity of beetles, bumblebees, and muscoids was positively predicted by the variation in blossom density, while syrphid activity was better predicted by plant species richness. Overall, the models for beetles and bumblebees explained much more of the variation in activity compared with the models for the dipterans, and blossom density was a better predictor of both flower visitor richness and activity than was plant species richness.
Phylogeographic information systems: putting the geography into phylogeography
Authors: Kidd David M. , Ritchie Michael G.
Published: August 2006

Phylogeography is concerned with the observation, description and analysis of the spatial distribution of genotypes and the inference of historical scenarios. In the past, the discipline has concentrated on the historical ‘phylo‐’ component through the utilization of phylogenetic analyses. In contrast, the spatial ‘‐geographic’ component is not a prominent feature of many existing phylogenetic approaches and has often been dealt with in a relatively naive fashion. Recently, there has been a resurgence of interest in the importance of geography in evolutionary biology. Thus, we believe that it is time to assess how geographic information is currently handled and incorporated into phylogeographical analysis. Geographical information systems (GISs) are computer systems that facilitate the integration and interrelation of different geographically referenced data sets; however, so far they have been little utilized by the phylogeographical community to manage, analyse and disseminate phylogeographical data. However, the growth in individual studies and the resurgence of interest in the geographical components of genetic pattern and biodiversity should stimulate further uptake. Some advantages of GIS are the integration of disparate data sets via georeferencing, dynamic data base design and update, visualization tools and data mining. An important step in linking GIS to existing phylogeographical and historical biogeographical analysis software and the dissemination of spatial phylogenies will be the establishment of ‘GeoPhylo’ data standards. We hope that this paper will further stimulate the resurgence of geography as an equal partner in the symbiosis that is phylogeography as well as advertise some benefits that can be obtained from the application of GIS practices and technologies.
Knowledge and attitudes of medical, nursing, dentistry and health technician students towards organ donation: a pilot study
Authors: Goz Fugen , Goz Mustafa , Erkan Medıne
Published: August 2006

Aim.  This pilot study assesses the knowledge and attitudes of medicine, nursing, dentistry and health technical students toward organ donation.

Background.  Medicine, nursing, dentistry and health technical students’ knowledge of and attitudes towards organ donation may be a factor in organ procurement rates. There is a lack of information about how Turkish medicine, nursing, dentistry and health technical students perceive organ donation, and what they know about it.

Method.  Students completed a self‐administered questionnaire after a lecture. The questionnaire included a test that was used to assess knowledge of and attitudes about organ donation.

Results.  Of the students, 56·8% were men, 91·4% were 18–24‐year old and 89·4% from east region of Turkey. Of students, 65·5% were willing, 9% were not willing, 25·5% were hesitant about organ donation and 6% of willing students reported carrying a signed card. The most common reason for unwillingness to organ donation was worries about illegal behaviours (2·4%). There was a statistical relationship between willingness of students for organ donation and gender but were not any statistical relationship between willingness of students for organ donation and age, school, region and recognizing relatives whose need organ transplantation. Majority of the students listed transplantable organs truly but 63·1% were had no idea about organ donation process.

Conclusion.  Students’ had a lack of information about organ donation. The results of this study support a greater emphasis on providing information regarding transplantation in medicine, nursing, dentistry and health technical schools to improve the knowledge of future heath care professionals about transplantation and organ donation issues.

Relevance to clinical practice.  These findings highlight a need to review these schools’ curricula and emphasize the importance of organ transplantation. This strategy may be part of the solution to the chronic shortage of donor organs for transplantation.
Brief interventions for high‐risk drinkers
Authors: Hyman Zena
Published: August 2006

Aims and objectives.  The purpose of this paper is to explore the literature on brief alcohol intervention and to review the literature that examines the status of the clinic nurse in the delivery of these interventions. The objective is to review critically the literature on brief intervention to create links for nurse developed and delivered brief intervention to high‐risk drinkers.

Background.  Population estimates suggest that more than one‐third of North Americans drink excessively with even higher rates for individuals treated in primary care settings. Alcohol use has been identified as the third leading cause of mortality in the United States. This problem is not unique to the US and, worldwide, agencies and governmental offices and ministries have issued recommendations to screen patients for alcohol misuse and deliver brief interventions to individuals considered to be high‐risk drinkers. Numerous randomized controlled trials and recent meta‐analyses have supported the use of screening and brief intervention for reducing alcohol consumption in primary healthcare settings. The vast majority of studies reporting on brief interventions have focused on the role of the physician with minimal if any involvement of the clinic nurse. A scant number of studies have been conducted that define and assess the role or potential role of the clinic nurse in providing screening and brief intervention to high‐risk drinkers in the primary care setting.

Methods.  Systematic review.

Results.  Six systematic reviews and meta‐analyses from an international base of studies support the use of brief intervention in the primary care setting. Three randomized control trials have highlighted the role of the staff or clinic nurse but there are no meta‐analyses addressing nurse‐delivered brief interventions. Numerous studies have explored factors effecting the implementation of brief intervention into the primary care setting.

Conclusion.  Brief intervention is recognized as a legitimate nursing role but little has been done to develop and define the role of the nurse in delivering brief interventions to high‐risk drinkers. This represents a major lacuna in both the nursing and alcoholism literature, where only a handful of studies have investigated nurse‐delivered brief intervention.

Relevance to clinical practice.  As health screening and health promotion are hallmarks of nursing care, nurses need to explore the use of brief intervention in their daily practice.
RT04 Challenges in teaching veterinary pharmacology and toxicology: some insights from cost‐free and open access public universities in Argentina
Authors: LANUSSE C.
Published: August 2006

Objective

After the Bologna declaration, signed by 29 European countries in 1999, a strong debate on veterinary education arose. Although at present none of the European veterinary schools have officially introduced the Bologna process to veterinary curricula, the discussion about the definition of competence and professional skill of graduates in veterinary medicine is controversial. In this context, veterinary pharmacology and toxicology are disciplines undergoing continuous development and becoming increasingly important in the different areas of veterinary profession. In this round‐table, different points of view on the challenge to teach Veterinary Pharmacology and Toxicology at a high quality level in the third millennium will be considered.
RT07 Understanding advantages and limitations of pre‐clinical studies for dose selection
Authors: MARTINEZ M. N.
Published: August 2006

Objective

There are several means whereby dosage schedules for clinical use may be set, some more appropriate and scientific than others! The challenge of the 21st century must be for colleagues in the pharmaceutical industry, those serving registration bodies and academic colleagues to pool their expertise with the objective of designing dosage schedules for clinical use, which are based on the application of sound scientific principles appropriate for each drug class. In this Roundtable Session colleagues of international standing will review (a) pharmacological and other sources of variability in the responses to drugs; (b) the advantages and limitations of pre‐clinical studies for dose selection; (c) the roles of population PK and population PK/PD together with Monte Carlo simulations in dosage regimen selection; (d) Bayesian approaches to dosage selection and (e) regulatory guidelines on the type and extent of studies required for selecting dosages. There is no unanimity amongst stakeholders on either the principles or the methods underlying dosage schedule design. Dose titration studies have long been the principal means of fixing doses but PK‐PD and population PK‐PD studies are now challenging more traditional approaches. The papers and discussion in this Roundtable Session will provide a critical basis for future advances in this crucial area of therapeutic drug usage. Getting the doses right means that the patient will receive maximum benefit, in terms of optimal efficacy with minimal toxicity, and hence correct dosing will contribute enormously to animal welfare.
WS02 Antimicrobial resistance epidemiology
Authors: BYWATER R.
Published: August 2006

Objective

Antimicrobial resistance is not only here, it is here to stay and it poses major threats to the effective use of antimicrobial drugs in humans and other animals. Nevertheless, a defeatist attitude is not acceptable. There is much that can and must be done to retard or prevent the emergence and spread of resistance. Clinicians and scientists from many disciplines have roles to play in combating resistance and we veterinary pharmacologists arguably have the most important role of all. As Schentag (1996) indicated 10 years ago, ‘‘The design of appropriate dosage regimens may be the single most important contribution of clinical pharmacology to the resistance problem’’. However, progress has not been rapid and as recently as 2003 Drusano commented, ‘‘One area in which there is little investigation is the use of proper dosing to help prevent emergence of resistance’’ and, again in 2005, Drusano et al. commented ‘‘little attention has been focussed on delineating the correct dose to suppress the amplification of less susceptible mutant bacterial sub‐populations’’. In this Workshop we address, with the help of internationally recognised authorities, antimicrobial resistance in veterinary medicine, from the perspectives of basic mechanisms, epidemiology and pre‐clinical and population PK‐PD modelling in dosage design. In addition, we review prudent use, clinical aspects and the contribution of regulatory efforts to minimise the selection of resistant microorganisms.