bluuebunny/crossref_metadata_2025 huggingface dataset:
Retracted: Transketolase A, an enzyme in central metabolism, derepresses the marRAB multiple antibiotic resistance operon of Escherichia coli by interaction with MarR
Authors: Domain Francis , Bina Xiaowen R. , Levy Stuart B.
Published: September 2007

Retraction: Francis Domain, Xiaowen R. Bina and Stuart B. Levy, “Transketolase A, an enzyme in central metabolism, derepresses the marRAB multiple antibiotic resistance operon of Escherichia coli by interaction with MarR”, Molecular Microbiology 2007, 66(2), 383‐393 (https://doi/10.1111/j.1365-2958.2007.05928.x). The above article, published online on 14 September 2007 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief John Helmann, and John Wiley & Sons Ltd. The retraction has been agreed because additional work in the authors' laboratory (L.M. McMurry) failed to confirm that the tktA gene overexpressed from pSPOK–TktA enhanced the expression in vivo of the mar promoter fusion marO–lacZ, or that deletion of chromosomal tktA reduced marO–lacZ expression. The original conclusions probably resulted from a yet unexplained variability of LacZ activity later discovered among different isolates of the marO–lacZ indicator strain SPC105. Moreover, the apparent binding of MarR to TktA‐6H immobilized on NiNTA resin (Fig. 1B) was an artefact caused by non‐specific binding of MarR alone to the resin that occurred when the wash contained no imidazole. Most MarR eluted in 20 mM imidazole without TktA‐6H. Therefore, the conclusion that TktA interacts physically with MarR is not warranted. It is noted that Xiaowen R. Bina was not involved in work related to these errors. Note that previously a corrigendum was published to note these concerns (Molecular Microbiology (2011) 80(3), 853).
Mutational analysis reveals Escherichia coli oriC interacts with both DnaA‐ATP and DnaA‐ADP during pre‐RC assembly
Authors: Grimwade Julia E. , Torgue Julien J.‐C. , McGarry Kevin C. , Rozgaja Tanya , Enloe Sareena T. , Leonard Alan C.
Published: September 2007

Prior to initiating DNA synthesis, Escherichia coli oriC switches from ORC, comprising initiator DnaA bound at three high‐affinity sites, to pre‐RC, when additional DnaA molecules interact with low‐affinity sites. Two types of low‐affinity sites exist: R boxes that bind DnaA‐ATP and DnaA‐ADP with equal affinity, and I‐sites with a three‐ to fourfold preference for DnaA‐ATP. To assess the regulatory role of weak DnaA interactions during pre‐RC assembly in vivo, we compared the behaviour of plasmid‐borne wild‐type oriC with mutants having an increased or decreased number of DnaA‐ATP discriminatory I‐sites. Increasing the number of discriminatory sites by replacing R5M with I2 inactivated extrachromosomal oriC function. Mutants with no discriminatory sites perturbed host growth and rapidly replaced wild‐type chromosomal oriC, but normal function returned if one I‐site was restored at either the I2, I3 or R5M position. These observations are consistent with assembly of E. coli pre‐RC in vivo from mixtures of DnaA‐ATP and DnaA‐ADP, with I‐site interactions coupling pre‐RC assembly to DnaA‐ATP levels.
Chaperones specific for the membrane‐bound [NiFe]‐hydrogenase interact with the Tat signal peptide of the small subunit precursor in Ralstonia eutropha H16
Authors: Schubert Torsten , Lenz Oliver , Krause Eberhard , Volkmer Rudolf , Friedrich Bärbel
Published: September 2007

Periplasmic membrane‐bound [NiFe]‐hydrogenases undergo a complex maturation pathway, including cofactor incorporation, subunit assembly, and finally twin‐arginine‐dependent membrane translocation (Tat). In this study, the role of the two accessory proteins HoxO and HoxQ in the maturation of the membrane‐bound [NiFe]‐hydrogenase (MBH) of Ralstonia eutropha H16 was investigated. MBH activity was absent in soluble as well as membrane fractions of cells with deletions in the respective genes. The absence of HoxO and HoxQ led to degradation of the small subunit precursor (preHoxK) of the MBH. The two accessory proteins directly interacted with preHoxK prior to assembly of active MBH dimer in the cytoplasm. MBH mutants with modified Tat signal peptides were disrupted in preHoxK/HoxO/HoxQ complex formation. Isolated HoxO and HoxQ proteins formed a complex in vitro with the chemically synthesized HoxK Tat signal peptide. Two functions of the two chaperones are discussed: (i) protection of the Fe–S cluster containing HoxK subunit under oxygenic conditions, and (ii) avoidance of HoxK export prior to dimerization with the large MBH subunit HoxG.
Radio galaxies in the 2SLAQ Luminous Red Galaxy Survey – I. The evolution of low-power radio galaxies to z∼ 0.7
Authors: Sadler Elaine M. , Cannon Russell D. , Mauch Tom , Hancock Paul J. , Wake David A. , Ross Nic , Croom Scott M. , Drinkwater Michael J. , Edge Alastair C. , Eisenstein Daniel , Hopkins Andrew M. , Johnston Helen M. , Nichol Robert , Pimbblet Kevin A. , De Propris Roberto , Roseboom Isaac G. , Schneider Donald P. , Shanks Tom
Published: September 2007

We have combined optical data from the 2dF-SDSS (Sloan Digital Sky Survey) LRG (Luminous Red Galaxy) and QSO (quasi-stellar object) (2SLAQ) redshift survey with radio measurements from the 1.4 GHz VLA (Very Large Array) FIRST (Faint Images of the Radio Sky at Twenty-cm) and NVSS (NRAO VLA Sky Survey) surveys to identify a volume-limited sample of 391 radio galaxies at redshift 0.4 < z < 0.7. By determining an accurate radio luminosity function for luminous early-type galaxies in this redshift range, we can investigate the cosmic evolution of the radio-galaxy population over a wide range in radio luminosity.

The low-power radio galaxies in our LRG sample (those with 1.4 GHz radio luminosities in the range 1024 to 1025 W Hz−1, corresponding to Fanaroff–Riley I (FR I) radio galaxies in the local Universe) undergo significant cosmic evolution over the redshift range 0 < z < 0.7, consistent with pure luminosity evolution of the form (1 +z)k, where k= 2.0 ± 0.3. Our results appear to rule out (at the 6–7σ level) models in which low-power radio galaxies undergo no cosmic evolution. The most powerful radio galaxies in our sample (with radio luminosities above 1026 W Hz−1) may undergo more rapid evolution over the same redshift range.

The evolution seen in the low-power radio-galaxy population implies that the total energy input into massive early-type galaxies from active galactic nucleus (AGN) heating increases with redshift, and was at least 50 per cent higher at z∼ 0.55 (the median redshift of the 2SLAQ LRG sample) than in the local universe.
Intestinal electrical stimulation improves delayed gastric emptying and vomiting induced by duodenal distension in dogs
Authors: Xu J. , Chen J. D. Z.
Published: September 2007

Abstract  The aim of this study was to investigate the effects of short‐pulse intestinal electrical stimulation (IES) on duodenal distention‐induced delayed gastric emptying and vomiting in dogs and its possible mechanisms. The study was performed in 12 dogs with jejunal electrodes and a duodenal cannula in three separate experiments to investigate the effects of IES on duodenal distension (DD)‐induced delayed gastric emptying and discomfort signs, vagal efferent activity, and jejunal tone. We found that: (i) IES significantly accelerated gastric emptying of liquid delayed by distension (18.05 ± 4.06%vs. 7.18 ± 1.99%, P = 0.036 at 60 min). (ii) IES significantly reduced vomiting and discomfort/pain induced by distension. The average signs score was 15.33 ± 1.37 during distension which decreased to 6.50 ± 0.91 (P = 0.0002) with IES. (iii) IES did not change vagal afferent activity, which was assessed by the spectral analysis of the heart rate variability. (iv) IES decreased jejunal tone. In conclusion, IES with parameters commonly used in gastric electrical stimulation for nausea and vomiting associated with gastroparesis improves DD‐induced delayed gastric emptying and prevents DD‐induced vomiting and discomfort signs. Further studies are warranted to investigate the therapeutic potential of IES for gastrointestinal symptoms associated with disturbances in motility and sensory function in small intestine.
Influence of the pattern of jejunal distension on mesenteric afferent sensitivity in the anaesthetized rat
Authors: Booth C. E. , Shaw J. , Hicks G. A. , Kirkup A. J. , Winchester W. , Grundy D.
Published: September 2007

Abstract  Vagal, spinal and intestino‐fugal fibres all potentially transmit mechanosensory afferent information from the gastrointestinal tract. We aimed to characterize the relative mechanosensitivity of these three different afferent populations supplying the rat jejunum. Afferent nerve discharge was recorded from pentobarbitone‐anaesthetized rats during different distension protocols. Saline ramp distension (1 mL min−1) and barostat ramp distension (2 mmHg 4 s−1) each evoked biphasic responses but with the latter significantly attenuated especially at low distending pressures. Barostat controlled phasic distensions (10–50 mmHg, 25 s) evoked an afferent response with a peak at the onset of distension adapting to a pleateau level that was maintained and comparable to the barostat ramp responses at the corresponding pressures. Chronic subdiaphragmatic vagotomy significantly attenuated the low pressure component of the response to balloon ramp distension and both peak and plateau responses to phasic distension. Single unit analysis showed an absence of low threshold afferent activity after vagotomy while the response to fibres with wide‐dynamic range and high threshold sensitivity were preserved hexamethonium had no effect on the responses to either ramp or phasic distension. These findings suggest that the nature of the distension stimulus is critical in determining the pattern of response observed from the various subpopulations of afferents supplying the bowel wall.
An audit of technical pitfalls of gastric barostat testing in dyspepsia
Authors: Tutuian R. , Vos R. , Karamanolis G. , Tack J.
Published: September 2007

Abstract  Sensorimotor dysfunction of the proximal stomach is considered an important mechanism for symptom generation in functional dyspepsia and related conditions. Barostat studies are used to assess gastric sensitivity to distention, compliance and meal‐induced accommodation. The aim of the present study was to assess tolerance and pitfalls of gastric barostat studies at a tertiary care centre. We performed a retrospective review of patient barostat studies between 01/2000 and 12/2004 at Leuven University Hospital. We evaluated compliance with the procedure, suggestions of air leaks, unusual sensory reporting, baseline intra‐balloon volumes, gastric accommodation and phasic contractions after a meal. About 98.1% of 414 scheduled gastric barostat studies were well tolerated and the majority (94.1%) were technically adequate. Interpretation was hampered in 18 (4.4%) studies because of low intra‐balloon volumes and in six (1.5%) studies because of suspected air leaks. Negative accommodation was found in 69% of studies with low volumes and in 9.8% of 382 studies with adequate volumes (27% patients with previous antireflux surgery). About 94% of gastric barostat studies in patients with upper gastrointestinal symptoms are well tolerated and technically adequate. Major artefacts are due to air leak or inappropriately low volumes.
Moulting reduces freeze susceptibility in the Antarctic mite Alaskozetes antarcticus (Michael)
Authors: HAWES T. C. , BALE J. S. , WORLAND M. R. , CONVEY P.
Published: September 2007

Abstract The effect of moulting on the cold hardiness of the oribatid mite Alaskozetes antarcticus (Michael) is investigated. Non moulting animals show clear seasonal patterns of cold hardiness with high supercooling points (SCPs) at the peak of summer and an increasing proportion of low SCPs with declining environmental temperatures. By contrast, both field‐fresh and laboratory acclimated (5 °C) mites in the moult state are consistently found to have low SCPs regardless of environmental temperature.
Oviposition response of scarabaeids: does ‘mother knows best’ about rainfall variability and soil moisture?
Authors: WARD ANDREW L. , ROGERS D. JOHN
Published: September 2007

Abstract The effect of soil moisture on ovipositional preference is studied for four melolonthine scarabaeids, Holotrichia reynaudi, Holotrichia serrata and Dermolepida albohirtum, which are endemic to the semiarid tropics of India (Holotrichia spp.) and Australia, and Heteronyx piceus, which is endemic to the temperate and subtropical regions of Australia. As predicted by the preference‐performance hypothesis, the three tropically adapted species show little or no ovipositional preference for soil moistures between permanent wilting point (−1500 kPa) and field capacity (−10 kPa) under either choice or no‐choice conditions in their endemic soils, whereas H. piceus shows a clear preference to oviposit in drier soils (−1500 to −200 kPa). The ovipositional soil‐moisture preferences of D. albohirtum and H. serrata are much narrower in geographically adjacent non‐endemic soils (between −1500 to −200 kPa) than in their endemic soils. An analysis of daily rainfall determined the rainfall variability within the endemic areas of each species. The semiarid tropics are highly variable, with rainfall at the time of oviposition being a poor predictor of the future rain required for successful larval development, whereas the rainfall in the subtropics is much more reliable. The absence of a clearly preferred soil moisture for oviposition in the tropically adapted species appears to be a life‐history strategy that allows these species to live in environments where rainfall is highly variable, and soil moisture at time of oviposition is a poor predictor of future environmental suitability for plant growth, and thus larval survival.
Body temperature of the parasitic wasp Pimpla turionellae (Hymenoptera) during host location by vibrational sounding
Authors: KRODER STEFAN , SAMIETZ JÖRG , STABENTHEINER ANTON , DORN SILVIA
Published: September 2007

Abstract The pupal parasitoid Pimpla turionellae (L.) uses self‐produced vibrations transmitted on the plant substrate, so‐called vibrational sounding, to locate immobile concealed pupal hosts. The wasps are able to use vibrational sounding reliably over a broad range of ambient temperatures and even show an increased signal frequency and intensity at low temperatures. The present study investigates how control of body temperature in the wasps by endothermic mechanisms may facilitate host location under changing thermal environments. Insect body temperature is measured with real‐time IR thermography on plant‐stem models at temperature treatments of 10, 18, 26 and 30 °C, whereas behaviour is recorded with respect to vibrational host location. The results reveal a low‐level endothermy that likely interferes with vibrational sound production because it occurs only in nonsearching females. At the lowest temperature of 10 °C, the thoracic temperature is 1.15 °C warmer than the ambient surface temperature whereas, at the high temperatures of 26 and 30 ° C, the wasps cool down their thorax by 0.29 and 0.47 °C, respectively, and their head by 0.45 and 0.61 °C below ambient surface temperature. By contrast, regardless of ambient temperature, searching females always have a slightly elevated body temperature of at most 0.30 °C above the ambient surface temperature. Behavioural observations indicate that searching females interrupt host location more frequently at suboptimal temperatures, presumably due to the requirements of thermoregulation. It is assumed that both mechanisms, producing vibrations for host location and low‐level endothermy, are located in the thorax. Endothermy by thoracic muscle work probably disturbs signal structure of vibrational sounding, so the processes cannot be used at the same time.
Capture of membrane components via trogocytosis occurs in vivo during both dendritic cells and target cells encounter by CD8+ T cells
Authors: Riond J. , Elhmouzi J. , Hudrisier D. , Gairin J. E.
Published: September 2007

Cytotoxic T lymphocytes recently stimulated by antigen‐presenting cells (APC) display major histocompatibility class (MHC) I and II molecules inherited from APC. We have previously reported that, in vitro, transfer of MHC molecules and several other proteins occurs through trogocytosis, i.e. the active acquisition of target cell membrane fragments by T lymphocytes. Here, using the model of viral antigen LCMVgp33‐41 recognition in transgenic P14 mice, we show that CD8+ T cells perform trogocytosis in vivo, as detected by the capture of biotin‐ or fluorescence‐labeled components of the APC surface. Trogocytosis occurs during interactions of CD8+ T cells with at least two kinds of cells: target cells and dendritic cells (DC). In lymph nodes, CD8+ T cells having performed trogocytosis with DC express the CD69 activation marker indicating that trogocytosis detects recently activated cells. Taken together, our findings suggest that trogocytosis may be a new in vivo marker of the recent interaction between a CD8+ T cell and its cellular partners or targets.
Late‐glacial and post‐glacial deposition in a large, low relief, epicontinental basin: the northern Baltic Sea
Authors: VIRTASALO JOONAS J. , KOTILAINEN AARNO T. , RÄSÄNEN MATTI E. , OJALA ANTTI E. K.
Published: September 2007

This paper presents a model of late‐glacial and post‐glacial deposition for the late‐Neogene sedimentary succession of the Archipelago Sea in the northern Baltic Sea. Four genetically related facies associations are described: (i) an ice‐proximal, acoustically stratified draped unit of glaciolacustrine rhythmites; (ii) an onlapping basin‐fill unit of rotated rhythmite clasts in an acoustically transparent to chaotic matrix interpreted as debris‐flow deposits; (iii) an ice‐distal, acoustically stratified to transparent, draped unit of post‐glacial lacustrine, weakly laminated to homogeneous deposits; and (iv) an acoustically stratified to transparent unit of brackish‐water, organic‐rich sediment drifts. The debris‐flow deposits of the unit 2 pass laterally into slide scars that truncate the unit 1; they are interpreted to result from a time interval of intense seismic activity due to bedrock stress release shortly after deglaciation of the area. Ice‐berg scouring and gravitational failure of oversteepened depositional slopes may also have contributed to the debris‐flow deposition. Comparisons to other late‐Neogene glaciated basins, such as the Hudson Bay or glacial lakes formed along the Laurentide ice sheet, suggest that the Archipelago Sea succession may record development typical for the deglaciation phase of large, low relief, epicontinental basins. The Carboniferous–Permian glacigenic Dwyka Formation in South Africa may provide an ancient analogue for the studied succession. Chronological control for the studied sediments is provided by the independent palaeomagnetic and AMS‐14C dating methods. In order to facilitate dating of the organic‐poor early post‐glacial deposits of the northern Baltic Sea, the 10 000 year long Lake Nautajärvi palaeomagnetic reference chronology (Ojala & Saarinen, 2002) is extended by 1200 years.
Spherical and columnar, septarian, 18O‐depleted, calcite concretions from Middle–Upper Permian lacustrine siltstones in northern Mozambique: evidence for very early diagenesis and multiple fluids
Authors: MELEZHIK VICTOR A. , FALLICK ANTHONY E. , SMITH RICHARD A. , ROSSE DANTA M.
Published: September 2007

Calcite septarian concretions from the Permian Beaufort Group in the Maniamba Graben (NW Mozambique) allow controls on the composition and nature of diagenetic fluids to be investigated. The concretions formed in lacustrine siltstones, where they occur in spherical (1 to 70 cm in diameter) and columnar (up to 50 cm long) forms within three closely spaced, discrete beds totalling 2·5 m in thickness. Cementation began at an early stage of diagenesis and entrapped non‐compacted burrows and calcified plant roots. The cylindrical concretions overgrew calcified vertical plant roots, which experienced shrinkage cracking after entrapment. Two generations of concretionary body cement and two generations of septarian crack infill are distinguished. The early generation in both cases is a low‐Mn, Mg‐rich calcite, whereas the later generation is a low‐Mg, Mn‐rich calcite. The change in chemistry is broadly consistent with a time (burial)‐related transition from oxic to sub‐oxic/anoxic conditions close to the sediment–water interface. Geochemical features of all types of cement were controlled by the sulphate‐poor environment and by the absence of bacterial sulphate reduction. All types of cement present have δ13C ranging between 0‰ and −15‰(Vienna Peedee Belemnite, V‐PDB), and highly variable and highly depleted δ18O (down to 14‰ Vienna Standard Mean Ocean Water, V‐SMOW). The late generation of cement is most depleted in both 13C and 18O. The geochemical and isotopic patterns are best explained by interaction between surface oxic waters, pore waters and underground, 18O‐depleted, reducing, ice‐meltwaters accumulated in the underlying coal‐bearing sediments during the Permian deglaciation. The invariant δ13C distribution across core‐to‐rim transects for each individual concretion is consistent with rapid lithification and involvement of a limited range of carbon sources derived via oxidation of buried plant material and from dissolved clastic carbonates. Syneresis of the cement during an advanced stage of lithification at early diagenesis is considered to be the cause of development of the septarian cracks. After cracking, the concretions retained a small volume of porosity, allowing infiltration of anoxic, Ba‐bearing fluids, resulting in the formation of barite. The results obtained contribute to a better understanding of diagenetic processes at the shallow burial depths occurring in rift‐bound, lacustrine depositional systems.
Submarine mass‐transport facies: new perspectives on flow processes from cores on the eastern North American margin
Authors: TRIPSANAS EFTHYMIOS K. , PIPER DAVID J. W. , JENNER KIMBERLEY A. , BRYANT WILLIAM R.
Published: September 2007

No comprehensive scheme yet exists to describe the depositional products of submarine sediment failures at the scale of piston cores, resulting in misinterpretation of failure deposits and overuse of the genetic term ‘debris flow’. Ninety‐nine sediment cores (0·5 to 20 m in length), from offshore eastern Canada and the Gulf of Mexico, are used to propose a descriptive sedimentary facies scheme with genetic implications for mass‐transport deposits. Seven facies are distinguished: (i) allochthonous stratified sediment; (ii) distorted stratified sediment; (iii) clast‐supported hard‐mud‐clast conglomerate; (iv) matrix‐supported mud‐clast conglomerate; (v) thin mud‐clast conglomerate (<0·8 m thick); (vi) diamicton; and (vii) sorted sand‐gravel deposits (≥0·05 m thick).

Seven genetic types of deposits are recognized. (i) Slumping of coherent sediment blocks (facies I). (ii) Slump and slide deposits (facies I and II). (iii) Debris‐avalanche deposits (hard sediment of facies I and II overlain by facies III). (iv) Low‐viscosity or large‐scale, high‐viscosity, cohesive debris flow deposits (facies IV, may have I, II, and III). (v) Very low‐viscosity debris flow deposits (facies V). (vi) Cohesionless debris flow deposits (facies VI). (vii) High‐density turbidity currents (facies VII). Vertical transitions between the genetic types were analysed by Markov chain analysis.

Although sedimentological transitions are inferred between deposits of slides and cohesive debris flows, their spatial distribution indicates that a cohesive debris flow forms principally in the initial stages of a sediment failure, suggesting that transformation depends mostly on the strength of the sediments. A genetic link is suggested for cohesionless debris flow deposits, which originate from the disintegration of sandy sediment on the upper continental slope, and the closely related turbidity current deposits. Debris avalanches are common in sedimentary marine environments with steep slopes (>10°). In many cases, geometrical and seismic characteristics of debris avalanche, slide and debris flow are similar, requiring core data to verify transport process.
Morphological characterization of cluster microforms
Authors: STROM K. B. , PAPANICOLAOU A. N.
Published: September 2007

A field study was conducted on two mountain streams in the Cascade Mountains of Washington State on the morphological characterization of cluster microforms. Morphological characterization of clusters is presented in terms of: (i) cluster shape; (ii) cluster geometric properties; and (iii) the spatial arrangement of clusters in the horizontal plane. Clusters were differentiated from other microtopography features such as reticulate structures and transverse ribs, and identified clusters were categorized by shape as being of pebble, line, comet, heap or ring type. The complex spatial arrangement of clusters at the sites was characterized by using a two‐dimensional correlation function, which allowed for measurement of the average cluster‐spacing properties. For the rivers examined, pebble‐shaped clusters were the most frequently observed cluster shape. Cluster geometric properties were found to be controlled by particles of the largest size fraction in the bed and the projected frontal width of the cluster – with cluster length being linearly related to cluster width for cluster width‐to‐height ratios <3·5. Results of the cluster‐spacing analysis suggest that cluster spacing increases with cluster size and decreases with local slope. Application of this principle to the available spacing data shows that cluster spacing λ scales with the ratio of S/d0 such that λS/d0 = constant, where S is the local slope and d0 the diameter of the largest particle in the cluster.
PRECLINICAL STUDY: Age‐dependent differences in sensitivity and sensitization to cannabinoids and ‘club drugs’ in male adolescent and adult rats
Authors: Wiley Jenny L. , Evans Rhys L. , Grainger Darren B. , Nicholson Katherine L.
Published: September 2007

Lifelong substance abuse is often initiated during adolescence; yet, most pre‐clinical research in this area has been conducted in adult animals. Substantial evidence exists that the brain development that continues throughout adolescence may result in pharmacological responses that differ in a crucial manner from those of adults. The goal of this study was to evaluate age differences in motor activity following acute and repeated administration of drugs that are commonly abused by adolescents, including cocaine, Δ9‐tetrahydrocannabinol (Δ9‐THC), and the club drugs, ketamine and 3,4‐methylenedioxymethamphetamine (MDMA). Adolescent and adult male rats were injected once daily with saline or with a dose of one of the test drugs for two 5‐day dosing periods, separated by a 2‐day drug holiday during which they remained in their home cages. Following each injection, rats were placed in a locomotor chamber for a 20‐minute session. The potencies of cocaine, ketamine and MDMA for producing motor stimulation were less in male adolescents than in male adults. Furthermore, sensitization to the club drug, ketamine, developed after repeated dosing in adults, but not adolescents. In contrast, adolescents were initially more sensitive to the stimulatory effects of low doses of Δ9‐THC than were adults, although rapid tolerance occurred. These results suggest that adolescents are less sensitive to the acute and repeated stimulant effects of some, but not all, of the drugs that are preferentially abused by this age group. This differential sensitivity may contribute to the different patterns of use that have been noted in adolescent versus adult drug abusers.
PRECLINICAL STUDY: Teratogenic effects of maternal antidepressant exposure on neural substrates of drug‐seeking behavior in offspring
Authors: Forcelli Patrick A. , Heinrichs Stephen C.
Published: September 2007

If neurotransmitter balance is upset in the developing nervous system by exposure to antidepressant drugs, structural and functional hedonic phenotypes of offspring may be affected. In order to test this hypothesis, two groups of pregnant Wistar dams were exposed to vehicle or fluoxetine by implantation on gestational day 14 of osmotic minipumps delivering 0 or 10 mg/kg/day fluoxetine for 14 days. The consequences of perinatal fluoxetine exposure on offspring conflict‐exploratory behavior were quantified using the elevated plus‐maze on postnatal day (PND) 30. Beginning on PND 60, the reinforcing properties of acutely administered cocaine were examined using a place conditioning procedure. Beginning on PND 90, a subset of rats were implanted with jugular catheters and allowed to acquire self‐administration of cocaine in an operant environment. In support of the hedonic modulation hypothesis, perinatal fluoxetine produced a significant decline in both nucleus accumbens cell count (−9%) and serotonin transporter‐like immunoreactivity in the raphe nucleus (−35%) on PND 120. In the elevated plus‐maze, perinatal fluoxetine exposure decreased (−21%) overall activity. In the place conditioning trial, only the fluoxetine‐treated group exhibited a significant place preference for the compartment paired previously with cocaine. In a cocaine self‐administration extinction trial, there was a statistically significant increase (350%) in extinction response rate among fluoxetine‐exposed offspring. These findings suggest that perinatal exposure to fluoxetine perturbs adult serotonergic neurotransmission and produces a positive hedonic shift for conditioned reinforcing effects of cocaine.
PRECLINICAL STUDY: Long‐lasting tolerance to alcohol following a history of dependence
Authors: Rimondini Roberto , Sommer Wolfang H. , Dall'Olio Rossella , Heilig Markus
Published: September 2007

Tolerance to alcohol effects is one of the defining features of clinical alcohol dependence. Here, we hypothesized that the post‐dependent state may include tolerance to sedative‐hypnotic alcohol actions. To address this question, we used a recently developed animal model in which repeated cycles of alcohol intoxication and withdrawal trigger long‐lasting behavioral plasticity. This animal model shares important features with the clinical condition. Animals were exposed to 7 weeks of intermittent alcohol vapor, allowed to recover for 3 weeks, and tested in protracted abstinence to exclude contributions from acute withdrawal. Post‐dependent and control rats were injected with a hypnotic dose of alcohol (3 g/kg), and the loss of righting reflex (LORR) was recorded, blood alcohol levels were monitored, and the elimination rate was calculated. Post‐dependent animals showed a decrease in LORR. Alcohol metabolism and elimination kinetics did not differ between groups. In conclusion, a history of alcohol dependence induces long‐lasting hypnotic tolerance. This process may play an important role in maintaining the dependent state.
PRECLINICAL STUDY: Effects of chronic stress on nicotine‐induced locomotor activity and corticosterone release in adult and adolescent rats
Authors: Cruz Fábio C. , DeLucia Roberto , Planeta Cleopatra S.
Published: September 2007

We examined nicotine‐induced locomotion and increase in corticosterone plasma levels in adolescent and adult animals exposed to chronic restraint stress. Adolescent [postnatal day (P) 28–37] and adult (P60–67) rats were restrained for 2 hours once daily for 7 days. Three days after the last exposure to stress, the animals were challenged with saline or nicotine (0.4 mg/kg subcutaneously). Nicotine‐induced locomotion was recorded in an activity cage. Trunk blood samples were collected in a subset of adolescent and adult rats and plasma corticosterone levels were determined by radioimmunoassay. Exposure to stress did not affect the nicotine‐induced locomotor‐ or corticosterone‐activating effects in both ages.
CLINICAL STUDY: Biodegradability of naltrexone‐poly(DL) lactide implants in vivo assessed under ultrasound in humans
Authors: Hulse Gary K. , Low Vincent H. S. , Stalenberg Virginia , Morris Noella , Thompson Richard I. , Tait Robert J. , Phan Cam T. , Ngo Hanh T. T. , Arnold‐Reed Diane E.
Published: September 2007

Ultrasound was used to assess the in vivo biodegradability of a sustained release poly(DL)lactide naltrexone implant in 71 persons previously treated for heroin dependence. We assessed 139 implant sites ranging from 2 to 1808 days post implant. Ultrasound assessment showed that implant tablets were initially well demarcated from each other and from the surrounding tissues. Biodegradation resulted in less demarcated tablets followed by clumping into a single mass‐like structure. This mass subsequently dispersed by approximately 1201 days post implant with no implant material visualized by ultrasound. The biodegradation was also assessed by visual clinical examination and palpation of the implant site as well as patient self‐report. These measures were generally well correlated with ultrasound results. Clinical assessment of the biodegradation process concluded that the implant changed from ‘firm’ to ‘less firm’ and from ‘initial square edge’ to ‘rounded edge’ tablets. Collectively, these data provide direct evidence of the in vivo absorption of the Go Medical implant over time, and its biodegradability in humans.
No association of KIR genes with Behcet’s disease
Authors: Middleton D. , Meenagh A. , Sleator C. , Gourraud P. A. , Ayna T. , Tozkir H. , Köse A. A. , Azizleri G. , Diler A. S.
Published: September 2007

Behcet’s disease (BD) is thought to be caused by multiple genetic, environmental and immunological factors, one of the most prominent being the strong association with human leucocyte antigen (HLA)‐Bw51, an HLA‐Bw4‐associated allele. We examined the presence/absence of 14 killer cell immunoglobulin‐like receptors (KIRs) and their ligands in 134 Turkish individuals with BD and compared the results with those of 154 ethnically matched controls. Although KIR3DL1 with its ligand (HLA‐Bw4) was significantly increased in the patients with BD (P = 0.0003), this no longer applied when the patients and controls were categorised by HLA‐Bw51 status. Thus, no association was identified between presence or absence of any of the 14 KIR genes studied and BD. In addition, we did not find any associations of KIR with various manifestations of the disease nor with gender or age of onset.
Overexpression of VvWRKY2 in tobacco enhances broad resistance to necrotrophic fungal pathogens
Authors: Mzid Rim , Marchive Chloé , Blancard Dominique , Deluc Laurent , Barrieu François , Corio‐Costet Marie‐France , Drira Nourredine , Hamdi Saïd , Lauvergeat Virginie
Published: September 2007

WRKY genes encode proteins belonging to a large family of transcription factors that are involved in various developmental and physiological processes and in plant responses to pathogen infections. In the present work, a full‐length cDNA from a Vitis vinifera L. cv. Cabernet Sauvignon grape berry library was isolated and characterized. The cDNA, designated VvWRKY2, encodes a polypeptide of 536 amino acids that shows the structural features of group I of WRKY protein family. VvWRKY2 is expressed in the different organs of healthy grapevine plants. In leaves, VvWRKY2 is induced by wounding and after infection with Plasmopara viticola. Constitutive expression of VvWRKY2 in tobacco reduced the susceptibility of transgenic tobacco to three types of fungal pathogens infecting different parts of the plant: Botrytis cinerea (leaves), Pythium spp. (roots) and Alternaria tenuis (seeds). The results indicate that VvWRKY2 may be involved in the resistance of grapevine against the pathogens.
Bacterial non‐host resistance: interactions of Arabidopsis with non‐adapted Pseudomonas syringae strains
Authors: Mishina Tatiana E. , Zeier Jürgen
Published: September 2007

Although interactions of plants with virulent and avirulent host pathogens are under intensive study, relatively little is known about plant interactions with non‐adapted pathogens and the molecular events underlying non‐host resistance. Here we show that two Pseudomonas syringae strains for which Arabidopsis is a non‐host plant, P. syringae pathovar (pv.) glycinea (Psg) and P. syringae pv. phaseolicola (Psp),induce salicylic acid (SA) accumulation and pathogenesis‐related gene expression at inoculation sites, and that induction of these defences is largely dependent on bacterial type III secretion. The defence signalling components activated by non‐adapted bacteria resemble those initiated by host pathogens, including SA, non‐expressor of PR‐1, non‐race specific disease resistance 1, phytoalexin‐deficient 4 and enhanced disease susceptibility 1. However, some differences in individual defence pathways induced by Psg and Psp exist, suggesting that for each strain, distinct sets of type III effectors are recognized by the plant. Although induction of SA‐related defences occurs, it does not directly contribute to bacterial non‐host resistance, because Arabidopsis mutants compromised in SA signalling and other classical defence pathways do not permit enhanced survival of Psg or Psp in leaves. The finding that numbers of non‐adapted bacteria in leaf extracellular spaces rapidly decline after inoculation suggests that they fail to overcome toxic or structural defence barriers preceding SA‐related responses. Consistent with this hypothesis, rapid, type III secretion system‐independent upregulation of the lignin biosynthesis genes, PAL1 and BCB, which might contribute to an early induced, cell wall‐based defence mechanism, occurs in response to non‐adapted bacteria. Moreover, knockout of PAL1 permits increased leaf survival of non‐host bacteria. In addition, different survival rates of non‐adapted bacteria in leaves from Arabidopsis accessions and mutants with distinct glucosinolate composition or hydrolysis exist. Possible roles for early inducible, cell wall‐based defences and the glucosinolate/myrosinase system in bacterial non‐host resistance are discussed.
Characteristics of photosynthesis and functions of the water–water cycle in rice (Oryza sativa) leaves in response to potassium deficiency
Authors: Weng Xiao‐Yan , Zheng Chen‐Juan , Xu Hong‐Xia , Sun Jian‐Yi
Published: September 2007

The mechanisms of photoprotection of photosynthesis and dissipation of excitation energy in rice leaves in response to potassium (K) deficiency were investigated. Net photosynthetic rate and the activity of ribulose‐1,5‐bisphosphate carboxylase/oxygenase decreased under K deficiency. Compared with the control, non‐photochemical quenching of Chl fluorescence increased in K‐deficient plant, whereas the efficiency of excitation transfer (F′v/F′m) and the photochemical quenching coefficient (qP) decreased. Thus, thermal dissipation of excitation energy increased as more excess electrons were accumulated in the photosynthetic chain. The electron transport rate through PSII (Jf) was more sensitive to O2 concentration, and the fraction of electron transport rate required to sustain CO2 assimilation and photorespiration (Jg/Jf) was significantly decreased under K deficiency compared with the control. Furthermore, the alternative electron transport (Ja/Jf) was increased, indicating that a considerable amount of electrons had been transported to O2 during the water–water cycle in the K‐deficient leaves. Although the fraction of electron transport to photorespiration (Jo/Jf) was also increased in the K‐deficient leaves, it was less sensitive than that of the water–water cycle. With the generation of reactive oxygen species level, the activities of superoxide dismutase and ascorbate peroxidase, two of the key enzymes involved in scavenging of active oxygen species in the water–water cycle, also increased in K‐deficient rice. Therefore, it is likely that a series of photoprotective mechanisms were initiated in rice plants in response to K deficiency and the water–water cycle might be critical for protecting photosynthetic apparatus under K deficiency in rice.
Cutaneous manifestations of cytomegalovirus disease in renal transplant recipients: a case series
Authors: Kaisar M.O. , Kirwan R.M. , Strutton G.M. , Hawley C.M. , Mudge D.W. , Campbell S.B. , Johnson D.W. , Isbel N.M.
Published: September 2007

Abstract: Cytomegalovirus (CMV) is an important and well‐described opportunistic virus in the immunocompromised host, with infection occurring mainly after the first month in the new renal transplant recipient. CMV can present as primary infection, reinfection, or reactivation of latent disease. It is capable of protean manifestations. Cutaneous manifestations are variable, rare, and diagnosis often delayed. We present 3 cases of cutaneous CMV disease in renal transplant recipients. Manifestations in our patients included ulceration of the tongue and perianal areas, facial petechiae, and nodular lesion involving the ear. This case series serves to highlight the importance of early skin biopsy in the diagnosis and management of cutaneous CMV disease.
Unusual presentation of cytomegalovirus enteritis after liver and kidney transplantation
Authors: Alhyraba M. , Grim S.A. , Benedetti E. , Clark N.M.
Published: September 2007

Abstract: Cytomegalovirus (CMV) is a cause of significant morbidity and mortality in solid organ transplant recipients. Gastrointestinal (GI) tract infection by CMV in this population can cause symptomatic disease, which typically manifests as fever, abdominal pain, nausea, and bloody diarrhea. Erosive lesions of the GI mucosa are often evident on endoscopic exam. We report an unusual presentation of CMV enteritis in a kidney and liver transplant recipient with the development of acute onset voluminous watery diarrhea in the absence of other typical symptoms and subsequent progression to hypovolemic shock and acute renal failure. This case emphasizes the atypical presentations of common opportunistic infections that may occur in immunosuppressed hosts.
Estimation of genetic parameters and prediction of breeding values for multivariate threshold and continuous data in a simulated horse population using Gibbs sampling and residual maximum likelihood
Authors: Stock K.F. , Hoeschele I. , Distl O.
Published: September 2007

Simulated horse data were used to compare multivariate estimation of genetic parameters and prediction of breeding values (BV) for categorical, continuous and molecular genetic data using linear animal models via residual maximum likelihood (REML) and best linear unbiased prediction (BLUP) and mixed linear‐threshold animal models via Gibbs sampling (GS). Simulation included additive genetic values, residuals and fixed effects for one continuous trait, liabilities of four binary traits, and quantitative trait locus (QTL) effects and genetic markers with different recombination rates and polymorphism information content for one of the liabilities. Analysed data sets differed in the number of animals with trait records and availability of genetic marker information. Consideration of genetic marker information in the model resulted in marked overestimation of the heritability of the QTL trait. If information on 10 000 or 5000 animals was used, bias of heritabilities and additive genetic correlations was mostly smaller, correlation between true and predicted BV was always higher and identification of genetically superior and inferior animals was – with regard to the moderately heritable traits, in many cases – more reliable with GS than with REML/BLUP. If information on only 1000 animals was used, neither GS nor REML/BLUP produced genetic parameter estimates with relative bias ≤25% and BV correlation >50% for all traits. Selection decisions for binary traits should rather be based on GS than on REML/BLUP breeding values.
Fine mapping of a quantitative trait locus on chromosome 9 affecting non‐return rate in Swedish dairy cattle
Authors: Holmberg M. , Sahana G. , Andersson‐Eklund L.
Published: September 2007

We previously mapped a quantitative trait locus (QTL) affecting the trait non‐return rate at 56 days in heifers to bovine chromosome 9. The purpose of this study was to confirm and refine the position of the QTL by using a denser marker map and fine mapping methods. Five families that previously showed segregation for the QTL were included in the study. The mapping population consisted of 139 bulls in a granddaughter design. All bulls were genotyped for 25 microsatellite markers surrounding the QTL on chromosome 9. We also analysed the correlated trait number of inseminations per service period in heifers. Both traits describe the heifer's ability to become pregnant after insemination. Linkage analysis, linkage disequilibrium and combined linkage and linkage disequilibrium analysis were used to analyse the data. Analysis of the families jointly by linkage analysis resulted in a significant but broad QTL peak for non‐return rate. Results from the combined analysis gave a sharp QTL peak with a well‐defined maximum in between markers BMS1724 and BM7209, at the same position as where the highest peak from the linkage disequilibrium analysis was found. One of the sire families segregated clearly at this position and the difference in effects between the two sire haplotypes was 2.9 percentage units in non‐return rate. No significant results were found for the number of inseminations in the combined analysis.
Genetic parameters for the prevalence of osteochondrosis in the limb joints of South German Coldblood horses
Authors: Wittwer C. , Hamann H. , Rosenberger E. , Distl O.
Published: September 2007

Heritabilities were estimated for osteochondrosis (OC) in fetlock and hock joints and palmar/plantar osseous fragments in fetlock joints of South German Coldblood (SGC) horses using Residual Maximum Likelihood (REML) under a linear animal model. The analyses were based on the results of a standardized radiographic examination of 167 SGC horses with a mean age of 14 months. The heritabilities linearly estimated and transformed onto the liability scale were for OC in fetlock joints 0.16 and for OC in hock joints 0.04. Considering fetlock and hock OC together, results in a heritability of 0.17. Palmar/plantar osseus fragments of the fetlock joints showed a heritability of 0.48. We concluded that there is most likely a genetic component in the variation of the development of osteochondrosis in fetlock and hock joints as well as for palmar/plantar osseus fragments of fetlock joints of the investigated population of SGC horses.
Multi‐breed genetic evaluation in a Gelbvieh population
Authors: Legarra A. , Bertrand J.K. , Strabel T. , Sapp R.L. , Sánchez J.P. , Misztal I.
Published: September 2007

A multi‐breed model was presented for the genetic evaluation of growth traits in beef cattle. In addition to the fixed effects, random direct and maternal genetic effects, and random maternal permanent environmental effects are considered; the model also fits direct and maternal heterosis and direct and maternal breed‐of‐founder (BOF) × generation group effects using a Bayesian approach that weights prior literature estimates relative to information supplied by the dataset to which the model will be applied. The multi‐breed evaluation procedures also allow the inclusion of external evaluations for animals of other breeds. The multi‐breed model was applied to a dataset provided by the American Gelbvieh Association. Different analyses were conducted by varying the weights given to the prior literature relative to the information provided by the dataset. Large differences were observed for the heterosis estimates, the BOF × generation group effect estimates, and the predicted breeding values across breeds due to the weights posed on prior literature estimates versus estimates derived directly from data. However, the rankings within breed were observed to be relatively robust to the different weights on prior information.