bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe acute respiratory syndrome coronavirus (SARS-CoV) infection inhibition using spike protein heptad repeat-derived peptides
Authors: Bosch Berend Jan , Martina Byron E. E. , van der Zee Ruurd , Lepault Jean , Haijema Bert Jan , Versluis Cees , Heck Albert J. R. , de Groot Raoul , Osterhaus Albert D. M. E. , Rottier Peter J. M.
Published: May 2004

The coronavirus SARS-CoV is the primary cause of the life-threatening severe acute respiratory syndrome (SARS). With the aim of developing therapeutic agents, we have tested peptides derived from the membrane-proximal (HR2) and membrane-distal (HR1) heptad repeat region of the spike protein as inhibitors of SARS-CoV infection of Vero cells. It appeared that HR2 peptides, but not HR1 peptides, were inhibitory. Their efficacy was, however, significantly lower than that of corresponding HR2 peptides of the murine coronavirus mouse hepatitis virus (MHV) in inhibiting MHV infection. Biochemical and electron microscopical analyses showed that, when mixed, SARS-CoV HR1 and HR2 peptides assemble into a six-helix bundle consisting of HR1 as a central triple-stranded coiled coil in association with three HR2 α-helices oriented in an antiparallel manner. The stability of this complex, as measured by its resistance to heat dissociation, appeared to be much lower than that of the corresponding MHV complex, which may explain the different inhibitory potencies of the HR2 peptides. Analogous to other class I viral fusion proteins, the six-helix complex supposedly represents a postfusion conformation that is formed after insertion of the fusion peptide, proposed here for coronaviruses to be located immediately upstream of HR1, into the target membrane. The resulting close apposition of fusion peptide and spike transmembrane domain facilitates membrane fusion. The inhibitory potency of the SARS-CoV HR2-peptides provides an attractive basis for the development of a therapeutic drug for SARS.
Completion of neuronal migration regulated by loss of Ca
2+
transients
Authors: Kumada Tatsuro , Komuro Hitoshi
Published: May 2004

The migration of immature neurons constitutes one of the major processes by which the central nervous system takes shape. Completing the migration at the final destination requires the loss of cell body motility, but little is known about the signaling mechanisms underlying this process. Here, we show that a loss of transient Ca
2+
elevations triggers the completion of cerebellar granule cell migration. Simultaneous observation of the intracellular Ca
2+
levels and cell movement in cerebellar slices of the early postnatal mice revealed that granule cells exhibit distinct frequencies of the transient Ca
2+
elevations as they migrate in different cortical layers, and complete the migration only after the loss of Ca
2+
elevations. The reduction of the Ca
2+
elevation frequency by decreasing Ca
2+
influx, or by inhibiting the activity of phospholipase C, PKC, or Ca
2+
/calmodulin, halted the granule cell movement prematurely. In contrast, increasing the Ca
2+
elevation frequency by increasing Ca
2+
release from internal stores, or by elevating intracellular cAMP levels, significantly delayed the completion of granule cell migration. The timing of the loss of Ca
2+
elevations was intrinsically set in the granule cells and influenced by external cues. These results suggest that Ca
2+
signaling, dictated by multiple signaling systems, functions as a mediator for completing the migration of immature neurons.
Structural basis for nicotinamide cleavage and ADP-ribose transfer by NAD
+
-dependent Sir2 histone/protein deacetylases
Authors: Zhao Kehao , Harshaw Robyn , Chai Xiaomei , Marmorstein Ronen
Published: May 2004

Sir2 enzymes are broadly conserved from bacteria to humans and have been implicated to play roles in gene silencing, DNA repair, genome stability, longevity, metabolism, and cell physiology. These enzymes bind NAD
+
and acetyllysine within protein targets and generate lysine, 2′-
O
-acetyl-ADP-ribose, and nicotinamide products. To provide structural insights into the chemistry catalyzed by Sir2 proteins we report the high-resolution ternary structure of yeast Hst2 (
h
omologue of
S
ir
t
wo 2) with an acetyllysine histone H4 peptide and a nonhydrolyzable NAD
+
analogue, carba-NAD
+
, as well as an analogous ternary complex with a reaction intermediate analog formed immediately after nicotinamide hydrolysis, ADP-ribose. The ternary complex with carba-NAD
+
reveals that the nicotinamide group makes stabilizing interactions within a binding pocket harboring conserved Sir2 residues. Moreover, an asparagine residue, N116, strictly conserved within Sir2 proteins and shown to be essential for nicotinamide exchange, is in position to stabilize the oxocarbenium intermediate that has been proposed to proceed the hydrolysis of nicotinamide. A comparison of this structure with the ADP-ribose ternary complex and a previously reported ternary complex with the 2′-
O
-acetyl-ADP-ribose reaction product reveals that the ribose ring of the cofactor and the highly conserved β1–α2 loop of the protein undergo significant structural rearrangements to facilitate the ordered NAD
+
reactions of nicotinamide cleavage and ADP-ribose transfer to acetate. Together, these studies provide insights into the chemistry of NAD
+
cleavage and acetylation by Sir2 proteins and have implications for the design of Sir2-specific regulatory molecules.
Coral decline threatens fish biodiversity in marine reserves
Authors: Jones Geoffrey P. , McCormick Mark I. , Srinivasan Maya , Eagle Janelle V.
Published: May 2004

The worldwide decline in coral cover has serious implications for the health of coral reefs. But what is the future of reef fish assemblages? Marine reserves can protect fish from exploitation, but do they protect fish biodiversity in degrading environments? The answer appears to be no, as indicated by our 8-year study in Papua New Guinea. A devastating decline in coral cover caused a parallel decline in fish biodiversity, both in marine reserves and in areas open to fishing. Over 75% of reef fish species declined in abundance, and 50% declined to less than half of their original numbers. The greater the dependence species have on living coral as juvenile recruitment sites, the greater the observed decline in abundance. Several rare coral-specialists became locally extinct. We suggest that fish biodiversity is threatened wherever permanent reef degradation occurs and warn that marine reserves will not always be sufficient to ensure their survival.
Structural basis for recognition of the AGNN tetraloop RNA fold by the double-stranded RNA-binding domain of Rnt1p RNase III
Authors: Wu Haihong , Henras Anthony , Chanfreau Guillaume , Feigon Juli
Published: May 2004

Specific recognition of double-stranded RNA (dsRNA) by dsRNA-binding domains (dsRBDs) is involved in a large number of biological and regulatory processes. Although structures of dsRBDs in complex with dsRNA have revealed how they can bind to dsRNA in general, these do not explain how a dsRBD can recognize specific RNAs. Rnt1p, a member of the RNase III family of dsRNA endonucleases, is a key component of the
Saccharomyces cerevisiae
RNA-processing machinery. The Rnt1p dsRBD has been implicated in targeting this endonuclease to its RNA substrates, by recognizing hairpins closed by AGNN tetraloops. We report the solution structure of Rnt1p dsRBD complexed to the 5′ terminal hairpin of one of its small nucleolar RNA substrates, the snR47 precursor. The conserved AGNN tetraloop fold is retained in the protein-RNA complex. The dsRBD contacts the RNA at successive minor, major, and tetraloop minor grooves on one face of the helix. Surprisingly, neither the universally conserved G nor the highly conserved A are recognized by specific hydrogen bonds to the bases. Rather, the N-terminal helix fits snugly into the minor groove of the RNA tetraloop and top of the stem, interacting in a non-sequence-specific manner with the sugar-phosphate backbone and the two nonconserved tetraloop bases. Mutational analysis of residues that contact the tetraloop region show that they are functionally important for RNA processing in the context of the entire protein
in vivo
. These results show how a single dsRBD can convey specificity for particular RNA targets, by structure specific recognition of a conserved tetraloop fold.
A balance between the
diap1
death inhibitor and
reaper
and
hid
death inducers controls steroid-triggered cell death in
Drosophila
Authors: Yin Viravuth P. , Thummel Carl S.
Published: May 2004

The steroid hormone ecdysone directs the massive destruction of obsolete larval tissues during
Drosophila
metamorphosis, providing a model system for defining the molecular mechanisms of steroid-regulated programmed cell death. Although earlier studies have identified an ecdysone triggered genetic cascade that immediately precedes larval tissue cell death, no death regulatory genes have been functionally linked to this death response. We show here that ecdysone-induced expression of the death activator genes
reaper
(
rpr
) and
head involution defective
(
hid
) is required for destruction of the larval midgut and salivary glands during metamorphosis, with
hid
playing a primary role in the salivary glands and
rpr
and
hid
acting in a redundant manner in the midguts. We also identify the
Drosophila
inhibitor of apoptosis 1 as a survival factor in the larval cell death pathway, delaying death until its inhibitory effect is overcome by
rpr
and
hid
. This study reveals functional interactions between
rpr
and
hid
in
Drosophila
cell death responses and provides evidence that the precise timing of larval tissue cell death during metamorphosis is achieved through a steroid-triggered shift in the balance between the
Drosophila
inhibitor of apoptosis 1 and the
rpr
and
hid
death activators.
Hippocampal long-term depression and long-term potentiation encode different aspects of novelty acquisition
Authors: Kemp Anne , Manahan-Vaughan Denise
Published: May 2004

The hippocampus is required for encoding spatial information. Little is known however, about how different attributes of learning are related to different types of synaptic plasticity. Here, we investigated the association between long-term depression (LTD) and long-term potentiation, both cellular models for learning, and novelty exploration. We found that exploration of a new environment containing unfamiliar objects and/or familiar objects in new locations facilitated LTD, whereas exploration of the new environment itself, in the absence of objects, impaired LTD. Furthermore, we found this phenomenon to be modulated by 5-hydroxytryptamine 4 receptor activation. In contrast, long-term potentiation was facilitated by exploration of an empty novel environment, but simultaneous object exploration caused depotentiation. We also found that no further LTD could be induced. These findings support a decisive role for LTD in the acquisition of object–place configuration and consolidate its candidacy as a learning mechanism.
Pharmacodynamic Interaction between Propofol and Remifentanil Regarding Hypnosis, Tolerance of Laryngoscopy, Bispectral Index, and Electroencephalographic Approximate Entropy
Authors: Bouillon Thomas W. , Bruhn Jörgen , Radulescu Lucian , Andresen Corina , Shafer Thomas J. , Cohane Carol , Shafer Steven L.
Published: May 2004

Background

The purpose of this investigation was to describe the pharmacodynamic interaction between propofol and remifentanil for probability of no response to shaking and shouting, probability of no response to laryngoscopy, Bispectral Index (BIS), and electroencephalographic approximate entropy (AE).

Methods

Twenty healthy volunteers received either propofol or remifentanil alone and then concurrently with a fixed concentration of remifentanil or propofol, respectively, via a target-controlled infusion. Responses to shaking and shouting and to laryngoscopy were assessed multiple times after allowing for plasma effect site equilibration. The raw electroencephalogram and BIS were recorded throughout the study, and AE was calculated off-line. Response surfaces were fit to the clinical response data using logistic regression or hierarchical response models. Response surfaces were also estimated for BIS and AE. Surfaces were visualized using three-dimensional rotations. Model parameters were estimated with NONMEM.

Results

Remifentanil alone had no appreciable effect on response to shaking and shouting or response to laryngoscopy. Propofol could ablate both responses. Modest remifentanil concentrations dramatically reduced the concentrations of propofol required to ablate both responses. The hierarchical response surface described the data better than empirical logistic regression. BIS and AE are more sensitive to propofol than to remifentanil.

Conclusions

Remifentanil alone is ineffective at ablating response to stimuli but demonstrates potent synergy with propofol. BIS and AE values corresponding to 95% probability of ablating response are influenced by the combination of propofol and remifentanil to achieve this endpoint, with higher propofol concentrations producing lower values for BIS and AE.
Parental Auricular Acupuncture as an Adjunct for Parental Presence during Induction of Anesthesia
Authors: Wang Shu-Ming , Maranets Inna , Weinberg Megan E. , Caldwell-Andrews Alison A. , Kain Zeev N.
Published: May 2004

Background

The purpose of this study was to determine whether parental auricular acupuncture reduces parental preoperative anxiety and thus allows children to benefit from parental presence during induction of anesthesia.

Methods

Mothers of children who were scheduled to undergo surgery were randomly assigned to an acupuncture intervention group (auricular press needles at relaxation, tranquilizer point, and master cerebral point) or a sham acupuncture control group (auricular press needles at the shoulder, wrist, and extraneous auricular point). The intervention was performed at least 30 min before the child's induction of anesthesia. All mothers were present during induction of anesthesia. The behavioral and physiologic anxiety of mothers and children were rated during the perioperative process.

Results

: Multivariable analysis examining maternal anxiety as a function of group found a group-by-time interaction (F1,65 = 4.1, P = 0.04). That is, after induction, maternal anxiety in the acupuncture group was significantly lower (42.9 +/- 10 vs. 49.5 +/- 11; P = 0.014). A multivariate model (F1,65 = 4.8, P =0.031) also showed that children whose mothers received the acupuncture intervention were significantly less anxious on entrance to the operating room (34.9 +/- 20 vs. 47.4 +/- 26; P = 0.03) and during introduction of the anesthesia mask (38.6 +/- 25 vs. 55.6 +/- 31; P = 0.016). There were no significant differences in maternal blood pressure and heart rate between the two groups.

Conclusions

: Auricular acupuncture significantly decreased maternal anxiety during the preoperative period. Children of mothers who underwent acupuncture intervention benefitted from the reduction of maternal anxiety during the induction of anesthesia.
Effects of Imposed Acid–Base Derangement on the Cardiovascular Effects and Pharmacokinetics of Bupivacaine and Thiopental
Authors: Mather Laurence E. , Ladd Leigh A. , Copeland Susan E. , Chang Dennis H.-T.
Published: May 2004

Background

By changing physicochemical properties such as effective lipophilicity, changes in blood pH could alter the distribution, elimination, and effects of weakly ionizing drugs. The authors examined the outcome of imposed acid-base derangement on cardiovascular effects and myocardial and whole body pharmacokinetics of bupivacaine, a weak base, and thiopental, a weak acid.

Methods

Intravenous infusions of rac-bupivacaine HCl (37.5 mg) or rac-thiopental sodium (250 mg, subanesthetic dose) were administered over 3 min to previously instrumented conscious ewes with normal blood pH, acidemia imposed by lactic acid infusion, or alkalemia imposed by bicarbonate infusion. Hemodynamic and electrocardiographic effects were recorded; arterial and coronary sinus drug blood concentrations were analyzed by chiral high-performance liquid chromatography.

Results

Bupivacaine decreased myocardial contractility, coronary perfusion, heart rate, and cardiac output; however, cardiac output and stroke volume were not as affected by bupivacaine with acidemia. Thiopental decreased myocardial contractility and stroke volume and increased heart rate; acidemia enhanced the tachycardia and produced a greater decrease in stroke volume than with alkalemia. Taken as a whole, the cardiovascular changes were not systematically modified by acid-base derangement. Overall, the tissue distribution of bupivacaine was favored by alkalemia, but thiopental pharmacokinetics were essentially unaffected by acid-base derangement. Acid-base derangement did not influence the kinetics of either drug enantioselectively.

Conclusions

At the doses used, the hemodynamic and electrocardiographic effects of bupivacaine and thiopental were not systematically modified by acid-base derangement, nor were there changes in regional or whole body pharmacokinetics of either drug that were clearly related to acid-base status.
Continuous, Noninvasive, and Localized Microvascular Tissue Oximetry Using Visible Light Spectroscopy
Authors: Benaron David A. , Parachikov Ilian H. , Friedland Shai , Soetikno Roy , Brock-Utne John , van der Starre Peter J. A. , Nezhat Camran , Terris Martha K. , Maxim Peter G. , Carson Jeffrey J. L. , Razavi Mahmood K. , Gladstone Hayes B. , Fincher Edgar F. , Hsu Christopher P. , Clark F. Landon , Cheong Wai-Fung , Duckworth Joshua L. , Stevenson David K.
Published: May 2004

Background

The authors evaluated the ability of visible light spectroscopy (VLS) oximetry to detect hypoxemia and ischemia in human and animal subjects. Unlike near-infrared spectroscopy or pulse oximetry (SpO2), VLS tissue oximetry uses shallow-penetrating visible light to measure microvascular hemoglobin oxygen saturation (StO2) in small, thin tissue volumes.

Methods

In pigs, StO2 was measured in muscle and enteric mucosa during normoxia, hypoxemia (SpO2 = 40-96%), and ischemia (occlusion, arrest). In patients, StO2 was measured in skin, muscle, and oral/enteric mucosa during normoxia, hypoxemia (SpO2 = 60-99%), and ischemia (occlusion, compression, ventricular fibrillation).

Results

In pigs, normoxic StO2 was 71 +/- 4% (mean +/- SD), without differences between sites, and decreased during hypoxemia (muscle, 11 +/- 6%; P < 0.001) and ischemia (colon, 31 +/- 11%; P < 0.001). In patients, mean normoxic StO2 ranged from 68 to 77% at different sites (733 measures, 111 subjects); for each noninvasive site except skin, variance between subjects was low (e.g., colon, 69% +/- 4%, 40 subjects; buccal, 77% +/- 3%, 21 subjects). During hypoxemia, StO2 correlated with SpO2 (animals, r2 = 0.98; humans, r2 = 0.87). During ischemia, StO2 initially decreased at -1.3 +/- 0.2%/s and decreased to zero in 3-9 min (r2 = 0.94). Ischemia was distinguished from normoxia and hypoxemia by a widened pulse/VLS saturation difference (Delta < 30% during normoxia or hypoxemia vs. Delta > 35% during ischemia).

Conclusions

VLS oximetry provides a continuous, noninvasive, and localized measurement of the StO2, sensitive to hypoxemia, regional, and global ischemia. The reproducible and narrow StO2 normal range for oral/enteric mucosa supports use of this site as an accessible and reliable reference point for the VLS monitoring of systemic flow.
Intrathecal Opioids and Lower Urinary Tract Function
Authors: Kuipers Peter W. , Kamphuis Ed T. , van Venrooij Ger E. , van Roy John P. , Ionescu Traian I. , Knape Johannes T. , Kalkman Cor J.
Published: May 2004

Background

Intrathecal administration of opioids may cause lower urinary tract dysfunction. In this study, the authors compared the effects of morphine and sufentanil administered intrathecally in a randomized double-blind fashion (two doses each) on lower urinary tract function in healthy male volunteers.

Methods

Urodynamic evaluation was performed before and every hour after drug administration up to complete recovery of lower urinary tract function using pressure and flow measurements recorded from catheters in the bladder and rectum. Sense of urge and urinary flow rates were assessed every hour by filling the bladder with its cystometric capacity and asking the patient to void. Full recovery was defined as a residual volume of less than 10% of bladder capacity and a maximum flow rate within 10% of the initial value.

Results

Intrathecal administration of both opioids caused dose-dependent suppression of detrusor contractility and decreased sensation of urge. Mean times to recovery of normal lower urinary tract function were 5 and 8 h after 10 or 30 microg sufentanil and 14 and 20 h after 0.1 or 0.3 mg morphine, respectively. This recovery profile can be explained by the spinal pharmacokinetics of both opioids.

Conclusions

Intrathecal opioids decrease bladder function by causing dose-dependent suppression of detrusor contractility and decreased sensation of urge. Recovery of normal lower urinary tract function is significantly faster after intrathecal sufentanil than after morphine, and the recovery time is clearly dose dependent.
Correlation between the Distribution of Contrast Medium and the Extent of Blockade during Epidural Anesthesia
Authors: Yokoyama Masataka , Hanazaki Motohiko , Fujii Hiromi , Mizobuchi Satoshi , Nakatsuka Hideki , Takahashi Toru , Matsumi Masaki , Takeuchi Mamoru , Morita Kiyoshi
Published: May 2004

Background

If the epidural spread of contrast medium can be well correlated with the spread of local anesthetics, epidurography can predict the dermatomal distribution of the anesthetic block. The authors evaluated the relation between radiographic and analgesic spread.

Methods

An epidural catheter was inserted in 90 patients, and predicted catheter tip position was recorded. The analgesic area was determined by pinprick after a 5-ml injection of 1.5% lidocaine, and epidurography was performed after a 5-ml injection of 240 mg I/ml iotrolan. Patients were assigned to three groups according to catheter tip position (group C: C-T4; group T: T5-T10; group L: T11-L), and patterns of spread were compared. In 16 of 90 subjects, radiographic and analgesic spread was further investigated after an additional 5-ml injection of iotrolan and lidocaine.

Results

The total radiographic spread correlated well with analgesic spread (right side: Y = 0.84 X + 0.16, r = 0.92, P < 0.01; left side: Y = 0.78 X + 0.45, r = 0.91, P < 0.01). The mean radiographic spread in the cephalad and caudal directions from the catheter tip also correlated well with mean analgesic spread (r = 0.97, P < 0.01, each direction). The mean distance between the predicted catheter tip and radiographically determined positions was 1.0 +/- 0.8 segments: the value in group T was significantly larger than that in groups C (P < 0.05) and L (P < 0.01). Although the correlation of radiographic spread with age was statistically significantly (r = 0.39, P < 0.01), great individual variation in spreading pattern was seen. In 16 subjects, mean radiographic spread correlated well with analgesic spread after 5- and 10-ml injections of iotrolan and lidocaine.

Conclusions

Epidurography is useful to indicate epidural catheter position and can help to predict the exact dermatomal distribution of analgesic block.
Phase Ia and Ib Study of Amitriptyline for Ulnar Nerve Block in Humans
Authors: Fridrich Peter , Eappen Sunil , Jaeger Walter , Schernhammer Eva , Zizza Anthony M. , Wang Ging Kuo , Gerner Peter
Published: May 2004

Background

The antidepressant amitriptyline is used as an adjuvant in the treatment of chronic pain conditions. Among its many actions, this drug also blocks ion channels, such as Na channels. Preliminary animal studies suggested that amitripty-line would be a longer-lasting local anesthetic than bupivacaine, with potentially fewer side effects. Therefore, the authors investigated the adverse effects and effectiveness of this drug when given for ulnar nerve blockade in human volunteers.

Methods

After obtaining written institutional review board approval and informed consent, a typical phase Ia trial was conducted by administration to the ulnar nerve at the level of the wrist in an open-label, dose-escalating fashion. Amitripty-line hydrochloride, 4 ml, at concentrations of 5, 10, and 20 mM (n = 4-9/group) was used for each volunteer. If no major side effects and nerve block were encountered, comparison in a randomized, double-blinded trial of amitriptyline (20 mM) to placebo and bupivacaine (4 mM) (n = 4-9/group), was to follow. A blunt needle was used to grade the pain, and motor blockade was assessed by the Froment test.

Results

There was no significant statistical difference in terms of side effects (pain, swelling, erythema, and sedation) among any groups. The analgesic effects of 20 mM amitriptyline and 4 mm bupivacaine solution were significantly higher than those of the placebo solution.

Conclusions

Because of the lack of evidence that amitripty-line provides better nerve blockade than current local anesthetics and the potential for neurotoxicity, its use for peripheral nerve blockade in humans seems limited.
Production of Paradoxical Sensory Hypersensitivity by α2-Adrenoreceptor Agonists
Authors: Quartilho Aline , Mata Heriberto P. , Ibrahim Mohab M. , Vanderah Todd W. , Ossipov Michael H. , Lai Josephine , Porreca Frank , Malan T. Philip
Published: May 2004

Background

Administration of opioid receptor agonists is followed by paradoxical sensory hypersensitivity. This hypersensitivity has been suggested to contribute to the antinociceptive tolerance observed with opioids. The authors hypothesized that alpha 2-adrenoreceptor agonists, which also produce antinociceptive tolerance, would produce sensory hypersensitivity.

Methods

alpha 2-Adrenoreceptor agonists were administered to male Sprague-Dawley rats as a single subcutaneous injection, a continuous subcutaneous infusion, a single intrathecal injection, or a continuous intrathecal infusion. Thermal sensitivity was determined using latency to withdrawal of the hind paw from radiant heat. Tactile sensitivity was determined using withdrawal threshold to von Frey filaments. Spinal dynorphin content was measured by enzyme immunoassay.

Results

Single systemic or intrathecal injections of clonidine or dexmedetomidine produced antinociception followed by delayed thermal and tactile hypersensitivity. Six-day systemic or intrathecal infusion of clonidine produced tactile and thermal hypersensitivity observed even during clonidine infusion. Sensory hypersensitivity was prevented by coadministration of the alpha 2-adrenoreceptor-selective antagonist idazoxan or the N-methyl-D-aspartate receptor-selective antagonist MK-801. Six-day infusion of intrathecal clonidine increased dynorphin content in dorsal lumbar spinal cord. MK-801 and dynorphin antiserum reversed clonidine-induced sensory hypersensitivity.

Conclusions

alpha 2-Adrenoreceptor agonists produce sensory hypersensitivity that may be analogous to that produced by opioids. Sensory hypersensitivity was prevented by idazoxan, demonstrating that it is mediated by alpha 2 receptors. Clonidine infusion increased spinal dynorphin content. Sensory hypersensitivity was prevented or reversed by MK-801 and dynorphin antiserum, implicating N-methyl-D-aspartate receptors and spinal dynorphin in its production. Clinicians should be mindful of the possibility of drug-induced hyperalgesia in patients treated with alpha 2-adrenoreceptor agonists.
The ankyrin repeat as molecular architecture for protein recognition
Authors: Mosavi Leila K. , Cammett Tobin J. , Desrosiers Daniel C. , Peng Zheng‐yu
Published: May 2004

The ankyrin repeat is one of the most frequently observed amino acid motifs in protein databases. This protein–protein interaction module is involved in a diverse set of cellular functions, and consequently, defects in ankyrin repeat proteins have been found in a number of human diseases. Recent biophysical, crystallographic, and NMR studies have been used to measure the stability and define the various topological features of this motif in an effort to understand the structural basis of ankyrin repeat‐mediated protein–protein interactions. Characterization of the folding and assembly pathways suggests that ankyrin repeat domains generally undergo a two‐state folding transition despite their modular structure. Also, the large number of available sequences has allowed the ankyrin repeat to be used as a template for consensus‐based protein design. Such projects have been successful in revealing positions responsible for structure and function in the ankyrin repeat as well as creating a potential universal scaffold for molecular recognition.
High resolution crystallographic studies of α‐hemolysin–phospholipid complexes define heptamer–lipid head group interactions: Implication for understanding protein–lipid interactions
Authors: Galdiero Stefania , Gouaux Eric
Published: May 2004

The α‐hemolysin is an archetypal pore‐forming protein that is secreted from Staphylococcus aureus as a water‐soluble monomer. When the monomer binds to the membrane of a susceptible cell, the membrane‐bound molecules assemble into the lytic heptamer. Although a bilayer or a bilayer‐like environment are essential to toxin assembly, there is no high resolution information on toxin–phospholipid complexes. We have determined the structures of detergent‐solubilized α‐hemolysin heptamer bound to glycerophospho‐choline or dipropanoyl glycerophosphocholine at 1.75–1.80 Å resolution and 110 K. The phosphocholine head group binds to each subunit in a crevice between the rim and the stem domains. The quaternary ammonium group interacts primarily with aromatic residues, whereas the phosphodiester moiety interacts with a conserved arginine residue. These structures provide a molecular basis for understanding why α‐hemolysin preferentially assembles on membranes comprised of phosphocholine lipids.
Inhibition of the Class II HMG–CoA reductase of Pseudomonas mevalonii
Authors: Hedl Matija , Rodwell Victor W.
Published: May 2004

There are two structural classes of HMG–CoA reductase, the third enzyme of the mevalonate pathway of isopentenyl diphosphate biosynthesis—the Class I enzymes of eukaryotes and the Class II enzymes of certain eubacteria. Structural requirements for ligand binding to the Class II HMG–CoA reductase of Pseudomonas mevalonii were investigated. For conversion of mevalonate to HMG–CoA the −CH3, −OH, and −CH2COO− groups on carbon 3 of mevalonate were essential for ligand recognition. The statin drug Lovastatin inhibited both the conversion of HMG–CoA to mevalonate and the reverse of this reaction. Inhibition was competitive with respect to HMG–CoA or mevalonate and noncompetitive with respect to NADH or NAD+. Ki values were millimolar. The over 104‐fold difference in statin Ki values that distinguishes the two classes of HMG–CoA reductase may result from differences in the specific contacts between the statin and residues present in the Class I enzymes but lacking in a Class II HMG–CoA reductase.
Scoring profile‐to‐profile sequence alignments
Authors: Wang Guoli , Dunbrack Roland L.
Published: May 2004

Sequence alignment profiles have been shown to be very powerful in creating accurate sequence alignments. Profiles are often used to search a sequence database with a local alignment algorithm. More accurate and longer alignments have been obtained with profile‐to‐profile comparison. There are several steps that must be performed in creating profile–profile alignments, and each involves choices in parameters and algorithms. These steps include (1) what sequences to include in a multiple alignment used to build each profile, (2) how to weight similar sequences in the multiple alignment and how to determine amino acid frequencies from the weighted alignment, (3) how to score a column from one profile aligned to a column of the other profile, (4) how to score gaps in the profile–profile alignment, and (5) how to include structural information. Large‐scale benchmarks consisting of pairs of homologous proteins with structurally determined sequence alignments are necessary for evaluating the efficacy of each scoring scheme. With such a benchmark, we have investigated the properties of profile–profile alignments and found that (1) with optimized gap penalties, most column–column scoring functions behave similarly to one another in alignment accuracy; (2) some functions, however, have much higher search sensitivity and specificity; (3) position‐specific weighting schemes in determining amino acid counts in columns of multiple sequence alignments are better than sequence‐specific schemes; (4) removing positions in the profile with gaps in the query sequence results in better alignments; and (5) adding predicted and known secondary structure information improves alignments.
Solution structure of the hypothetical protein Mth677 from Methanobacterium thermoautotrophicum: A novel α+β fold
Authors: Blanco Francisco J. , Yee Adelinda , Campos‐Olivas Ramón , Ortiz Ángel R. , Devos Demian , Valencia Alfonso , Arrowsmith Cheryl H. , Rico Manuel
Published: May 2004

The structure of Mth677, a hypothetical protein from Methanobacterium thermoautotrophicum (Mth), has been determined by using heteronuclear nuclear magnetic resonance (NMR) methods on a double‐labeled 15N‐13C sample. Mth677 adopts a novel α+β fold, consisting of two α‐helices (one N terminal and one C terminal) packed on the same side of a central β‐hairpin. This structure is likely shared by its three orthologs, detected in three other Archaebacteria. There are no clear features in the sequences of these proteins or in the genome organization of Mth to make a reliable functional assignment to this protein. However, the structural similarity to Escherichia coli MinE, the protein which controls that division occurs at the midcell site, lends support to the proposal that Mth677 might be, in Mth, the counterpart of the topological specificity domain of MinE in E. coli.
The Theory–Practice Issue in Policy Implementation Research
Authors: O'toole Laurence J.
Published: May 2004

Applying implementation theory to practice has been rare. Reasons include the difficulty of the theoretical challenge, the varied needs of practitioners and the complicating normative issues at stake. Nonetheless, several approaches can contribute to the efficacy of implementation action. Building on points of theoretical consensus is one strategy. A second is the systematic probing of points in theoretical dispute, to sketch out practical implications. A third is the development of a contingency perspective to determine which theoretical strands may be appropriate in a given case. Finally, tapping the emerging ideas built on a synthesis of partial perspectives is ultimately likely to be the most useful approach. New methodological tools can help select out valid high‐performing instances for systematic inspection and possible emulation. And some of the synthetic perspectives now available are amenable to heuristic application; these include approaches based upon reversible logic, game‐theoretic notions and contextual interaction theory.
Scrutiny and the Political Party Group in UK Local Government: New Models of Behaviour
Authors: Leach Steve , Copus Colin
Published: May 2004

The introduction, via the Local Government Act 2000, of political executives held to account by influential overview and scrutiny committees challenges fundamentally the traditional operations of the party group system. This paper uses evidence from a variety of sources (including the experience of Parliamentary select committees) to explore how councillors are managing the tensions between party group loyalty and the expectation surrounding the operation of scrutiny. Four models of party group behaviour are identified with the group acting as partner, arbitrator, filter and Leviathan respectively. These typologies are then used (together with research evidence) to interpret the circumstances in which effective scrutiny may be aided or hindered by party group dynamics. Three alternative scenarios, which illustrate the impact of different political dynamics on the effectiveness of scrutiny, are identified and explored. It is concluded that the success of the overview and scrutiny experiment is by no means assured and faced with the intransigent nature of most party group behaviour, the future of effective scrutiny hangs in the balance.
Modernizing Government in the Channel Islands: the Context and Problematic of Reform in a Differentiated but Feudal European Polity
Authors: Massey Andrew
Published: May 2004

This paper explores the dynamics for changes to the machinery of government and public administration in the Bailiwicks of Jersey and Guernsey. Although constitutionally Crown possessions and under the jurisdiction of the UK, both territories are self‐governing and are neither part of the UK nor the EU. Their importance as major offshore tax havens means that questions should be asked about their ability to effectively police the money that is invested through them, an issue that has acquired increased significance in the wake of recent terrorist events. Questions of financial probity inevitably lead to questions about governance and governmental efficiency and effectiveness. This paper explores the Bailiwicks’ reactions to this within the theoretical context of the differentiated polity and the modernizing government and new public management agenda. The paper suggests the unique and entrenched political culture of the Bailiwicks is resistant to change but will embrace it if that change ensures the continuance of their autonomy, within the context of being Crown possessions.
Contact allergy to farnesol in 2021 consecutively patch tested patients. Results of the IVDK*
Authors: Schnuch Axel , Uter Wolfgang , Geier Johannes , Lessmann Holger , Frosch Peter J.
Published: May 2004

Farnesol is one of the fragrances considered to be a significant contact allergen. Therefore, it was decided by the European Union to label products containing farnesol. Farnesol was tested [5% petrolatum (pet.)] together with the standard series between 1 January 2003 and 30 June 2003 in 2021 consecutive patients, 1243 females and 778 males. Of these, 22 [1.1%, 95% confidence interval (CI): 0.7–1.6%] had a positive reaction to farnesol. 147 (8.1%) of those 1825 tested to Myroxylon pereirae resin (balsam of Peru, 25% pet.) at the same time reacted positively, 143 (7.8%) of those 1823 tested to the fragrance mix (FM) (8% pet.) and 34 (1.9%) of 1831 tested to propolis (10% pet.). With regard to concomitant reactions in farnesol‐positive patients, 5 of 22 reacted additionally to the FM [odds ratio (OR): 4.3; CI: 1.53–12.15] and 2 (of these 5) additionally to M. pereirae resin (OR: 1.27; CI: 0.29–5.54). The strongest association was seen to propolis (OR: 6.2; 95% CI: 1.4–27.7). Compared to those with negative reactions to farnesol, the group of patients allergic to farnesol was characterized by a higher proportion of young females and office workers, and the hand and the face were more often affected. In conclusion, farnesol is an important allergen. We recommend that farnesol should be included in a fragrance patch‐test preparation and that its use should be regulated for consumer safety reasons. Furthermore, the extent of exposure to farnesol should be further studied.
Ground beetle species (Coleoptera, Carabidae) associations with land cover variables in northern England and southern Scotland
Authors: Eyre M. D. , Luff M. L.
Published: May 2004

Distribution data concerning 172 ground beetle species derived from 1145 pitfall trap sites in northern England and southern Scotland were used to assess the relationship between species distribution and 12 satellite‐derived land cover variables at the regional scale. A number of species were strongly associated with one cover type and negatively with others. The major variation was for preferences for covers in upland or lowland parts of the region. Other distinct preferences for some species were covers such as those at the coast whilst a number of common species showed no strong preference for any cover variable. The synthesis of ground beetle species distribution and satellite‐derived cover data is discussed in relation to environmental assessment and change.
Evaluating empirical scaling relations of pattern metrics with simulated landscapes
Authors: Shen Weijun , Darrel Jenerette G. , Wu Jianguo , H. Gardner Robert
Published: May 2004

Landscape patterns demonstrate scale‐dependent properties that have been parsimoniously described by empirical scaling functions. These functions, derived from multiple‐scale analysis of real landscapes, are evaluated here for their generality and robustness via a series of simulated landscapes with known landscape patterns. A factorial design was used to generate these landscapes, varying the number of classes, class abundance distribution, and patch dispersion. The results confirm that the three types of scaling relations were both general and robust. Type I metrics were predictable with simple scaling functions (e.g. power laws or linear functions); Type II metrics showed stair‐case like response patterns and were essentially not predictable; Type III metrics exhibited erratic response patterns that were unpredictable in most cases. However, significant differences were found between real and simulated landscapes when landscape extent was increased. Systematic changes in grain size show that the predictability of scaling relations increases with the number of classes, the evenness of class abundance distribution, and the aggregation of patch dispersion. However, random patch dispersion seemed to enhance the predictability of scaling relations when changing spatial extent.
A local nearest‐neighbor convex‐hull construction of home ranges and utilization distributions
Authors: Getz Wayne M. , Wilmers Christopher C.
Published: May 2004

We describe a new method for estimating the area of home ranges and constructing utilization distributions (UDs) from spatial data. We compare our method with bivariate kernel and α‐hull methods, using both randomly distributed and highly aggregated data to test the accuracy of area estimates and UD isopleth construction. The data variously contain holes, corners, and corridors linking high use areas. Our method is based on taking the union of the minimum convex polygons (MCP) associated with the k−1 nearest neighbors of each point in the data and, as such, has one free parameter k. We propose a “minimum spurious hole covering” (MSHC) rule for selecting k and interpret its application in terms of type I and type II statistical errors. Our MSHC rule provides estimates within 12% of true area values for all 5 data sets, while kernel methods are worse in all cases: in one case overestimating area by a factor of 10 and in another case underestimating area by a factor of 50. Our method also constructs much better estimates for the density isopleths of the UDs than kernel methods. The α‐hull method does not lead directly to the construction of isopleths and also does not always include all points in the constructed home range. Finally we demonstrate that kernel methods, unlike our method and the α‐hull method, does not converges to the true area represented by the data as the number of data points increase.
Biological trait composition of European stream invertebrate communities: assessing the effects of various trait filter types
Authors: Statzner Bernhard , Dolédec Sylvain , Hugueny Bernard
Published: May 2004

Understanding the action of filters on the biological trait composition of communities is constrained by the multitude of filter types (e.g. abiotic vs biotic, actual vs historical) that may cause changes of a multitude of traits (e.g. small vs large body size, short vs long life cycle) at a multitude of spatial scales (e.g. continent vs landscape vs local site). Using published data on the as natural as possible abundances and 11 biological traits (described through 63 categories) of 254 European stream invertebrate genera, we assessed how already available knowledge can serve to identify the importance of the action of different types of trait filters at two spatial scales. Therefore, we analysed observed and simulated abundance‐weighted trait compositions at the local scale of 384 running water sites (RWS) and at the landscape scale of 14 large biogeographical regions (LER). Actual abiotic filters acted significantly and independently of the taxonomic richness on the invertebrate traits at the RWS‐ and LER‐scale, whereas biotic filters had no significant effect. Evidence for the action of historical trait filters across Europe was only weak at both scales. Size, reproductive cycle, respiration and locomotion technique, feeding habits and vulnerability to disturbance responded to altitude and stream width of the RWS according to existing views about the effects of riparian, physiological, interstitial or disturbance controls of these traits. These controls acted independently on trait categories that did not co‐occur within the genera, because correlations of size categories with other trait categories were higher in the abundance‐weighted trait array (across communities) than in the original trait array (across genera). Overall, many of the 63 trait categories were scarcely affected by the trait filters considered in this study. Therefore, we briefly discuss potential effects of continental filters and of stream system‐specific, local physical filters, as the latter should produce similar trait patterns on a global scale. Our study suggests that analyses of the currently available knowledge can simplify the complicated hypothetical framework on trait filter actions, which sharpens the focus on future research needs.
Smad3 as a mediator of the fibrotic response
Authors: Flanders Kathleen C.
Published: May 2004

Transforming growth factor‐β (TGF‐β) plays a central role in fibrosis, contributing to the influx and activation of inflammatory cells, the epithelial to mesenchymal transdifferentiation (EMT) of cells and the influx of fibroblasts and their subsequent elaboration of extracellular matrix. TGF‐β signals through transmembrane receptor serine/threonine kinases to activate novel signalling intermediates called Smad proteins, which modulate the transcription of target genes. The use of mice with a targeted deletion of Smad3, one of the two homologous proteins which signals from TGF‐β/activin, shows that most of the pro‐fibrotic activities of TGF‐β are mediated by Smad3. Smad3 null inflammatory cells and fibroblasts do not respond to the chemotactic effects of TGF‐β and do not autoinduce TGF‐β. The loss of Smad3 also interferes with TGF‐β‐mediated induction of EMT and genes for collagens, plasminogen activator inhibitor‐1 and the tissue inhibitor of metalloprotease‐1. Smad3 null mice are resistant to radiation‐induced cutaneous fibrosis, bleomycin‐induced pulmonary fibrosis, carbon tetrachloride‐induced hepatic fibrosis as well as glomerular fibrosis induced by induction of type 1 diabetes with streptozotocin. In fibrotic conditions that are induced by EMT, such as proliferative vitreoretinopathy, ocular capsule injury and glomerulosclerosis resulting from unilateral ureteral obstruction, Smad3 null mice also show an abrogated fibrotic response. Animal models of scleroderma, cystic fibrosis and cirrhosis implicate involvement of Smad3 in the observed fibrosis. Additionally, inhibition of Smad3 by overexpression of the inhibitory Smad7 protein or by treatment with the small molecule, halofuginone, dramatically reduces responses in animal models of kidney, lung, liver and radiation‐induced fibrosis. Small moleucule inhibitors of Smad3 may have tremendous clinical potential in the treatment of pathological fibrotic diseases.