bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antirepression as a second mechanism of transcriptional activation by a minor groove binding protein
Authors: Smits Wiep Klaas , Hoa Tran Thu , Hamoen Leendert W. , Kuipers Oscar P. , Dubnau David 
Published: May 2007

SummaryCompetence for genetic transformation in the bacterium Bacillus subtilis is a bistable differentiation process governed by the minor groove DNA binding protein ComK. No detectable comK transcription occurs in the absence of an intact comK gene, indicating that ComK has auto‐activating properties. ComK auto‐stimulation, which is dependent on ComK binding to the comK promoter, is a critical step in competence development, ensuring quick and high‐level expression of the late‐competence genes. Auto‐stimulation is also essential for the bistable expression pattern of competence. Here, we demonstrate that ComK acts as an activator at its own promoter by antagonizing the action of two repressors, Rok and CodY. Importantly, antirepression occurs without preventing binding of the repressing proteins, suggesting that ComK and the repressors might bind at distinct surfaces of the DNA helix. DegU, a DNA binding protein known to increase the affinity of ComK for its own promoter, potentiates the antirepression activity of ComK. We postulate that antirepression is primarily achieved through modulation of DNA topology. Although to our knowledge ComK is the only DNA binding protein shown to act in this novel fashion, other minor groove binding proteins may act similarly.
Differences intrans‐stimulated chloroquine efflux kinetics are linked to PfCRT inPlasmodium falciparum
Authors: Sanchez Cecilia P. , Rohrbach Petra , McLean Jeremy E. , Fidock David A. , Stein Wilfred D. , Lanzer Michael 
Published: May 2007

SummaryThe mechanism underpinning chloroquine drug resistance in the human malarial parasitePlasmodium falciparumhas remained controversial. Currently discussed models include a carrier or a channel for chloroquine, the former actively expelling the drug, the latter facilitating its passive diffusion, out of the parasite's food vacuole, where chloroquine accumulates and inhibits haem detoxification. Here we have challenged both models using an establishedtrans‐stimulation efflux protocol. While carriers may demonstratetrans‐stimulation, channels do not. Our data reveal that extracellular chloroquine stimulates chloroquine efflux in the presence and absence of metabolic energy in both chloroquine‐sensitive and ‐resistant parasites, resulting in a hyperbolic increase in the apparent initial efflux rates as the concentration of external chloroquine increases. In the absence of metabolic energy, the apparent initial efflux rates were comparable in both parasites. Significant differences were only observed in the presence of metabolic energy, where consistently higher apparent initial efflux rates were found in chloroquine‐resistant parasites. Astrans‐stimulation is characteristic of a carrier, and not a channel, we interpret our data in favour of a carrier for chloroquine being present in both chloroquine‐sensitive and ‐resistant parasites, however, with different transport modalities.
Identification and biochemical characterization of a novel carotenoid oxygenase: elucidation of the cleavage step in the Fusarium carotenoid pathway
Authors: Prado‐Cabrero Alfonso , Estrada Alejandro F. , Al‐Babili Salim , Avalos Javier 
Published: May 2007

SummaryThe synthesis of the acidic apo‐carotenoid neurosporaxanthin by the fungus Fusarium fujikuroi depends on four enzyme activities: phytoene synthase and carotene cyclase, encoded by the bifunctional gene carRA, a carotene desaturase, encoded by carB, and a postulated cleaving enzyme converting torulene (C40) into neurosporaxanthin (C35). Based on sequence homology to carotenoid oxygenases, we identified the novel fungal enzyme CarT. Sequencing of the carT allele in a torulene‐accumulating mutant of F. fujikuroi revealed a mutation affecting a highly conserved amino acid, and introduction of a heterologous carT gene in this mutant restored the ability to produce neurosporaxanthin, pointing to CarT as the enzyme responsible for torulene cleavage. Expression of carT in lycopene‐accumulating E. coli cells resulted in the formation of minor amounts of apo‐carotenoids, but no enzymatic activity was observed in β‐carotene‐accumulating cells, indicating a preference for acyclic or monocyclic carotenes. The purified CarT enzyme efficiently cleaved torulene in vitro to produce β‐apo‐4′‐carotenal, the aldehyde corresponding to the acidic neurosporaxanthin, and was also active on other monocyclic synthetic substrates. In agreement with its role in carotenoid biosynthesis, the carT transcript levels are induced by light and upregulated in carotenoid‐overproducing mutants, as already found for other car genes.
A new assembly pathway for the cytokinetic Z ring from a dynamic helical structure in vegetatively growing cells of Bacillus subtilis
Authors: Peters Phoebe C. , Migocki Margaret D. , Thoni Carola , Harry Elizabeth J. 
Published: May 2007

SummaryThe earliest event in bacterial cell division is the formation of a Z ring, composed of the tubulin‐like FtsZ protein, at the division site at midcell. This ring then recruits several other division proteins and together they drive the formation of a division septum between two replicated chromosomes. Here we show that, in addition to forming a cytokinetic ring, FtsZ localizes in a helical‐like pattern in vegetatively growing cells of Bacillus subtilis. FtsZ moves rapidly within this helix‐like structure. Examination of FtsZ localization in individual live cells undergoing a single cell cycle suggests a new assembly mechanism for Z ring formation that involves a cell cycle‐mediated multistep remodelling of FtsZ polymers. Our observations suggest that initially FtsZ localizes in a helical pattern, with movement of FtsZ within this structure occurring along the entire length of the cell. Next, movement of FtsZ in a helical‐like pattern is restricted to a central region of the cell. Finally the FtsZ ring forms precisely at midcell. We further show that another division protein, FtsA, shown to interact with FtsZ prior to Z ring formation in B. subtilis, also localizes to similar helical patterns in vegetatively growing cells.
Incisional hernia following liver transplantation: incidence and predisposing factors
Authors: Kahn Judith , Müller Helmut , Iberer Florian , Kniepeiss Daniela , Duller Doris , Rehak Peter , Tscheliessnigg Karlheinz 
Published: May 2007

Abstract:  Background:  Patients after orthotopic liver transplantation (OLT) have a high risk of developing incisional hernia (IH). In the literature incidences between 5% and 17% are reported.Patients and methods:  In 90 patients, who underwent OLT between October 1998 and December 2005, a retrospective analysis on the occurrence of IH was performed. Surgical access for OLT was a transversal upper laparotomy. Age, gender, primary disease, ICU stay, immunosuppressive regimen and two different closure techniques (running suture or single sutures in layers) were evaluated.Results:  In 73 patients (76.7%, group 2) healing of the incision was without problems, in 17 patients (23.3%, group 1), IH occurred. Total survival was similar between the groups (86.3% vs. 94.1%, n.s.). No significant differences between the groups concerning age, gender, body mass index, platelet count and duration of ICU stay were found. Also, the technique of abdominal closure had no impact on the development of IH. No IH was found in patients with hepatocellular carcinoma (n = 15), whereas end‐stage liver cirrhosis (n = 75) was associated with development of IH (p = 0.064). Multivariate analysis revealed end‐stage liver cirrhosis, Sirolimus, and MMF to be independent significant risk factors for IH after OLT.Conclusion:  IH following OLT has to be regarded a frequent complication. While technique of abdominal closure seems to have no impact, primary diagnosis and kind of immunosuppressive regimen exerted a significant influence on the formation of IH.
Impact of Water Stress on Maize Grown Off‐Season in a Subtropical Environment
Authors: Soler C. M. T. , Hoogenboom G. , Sentelhas P. C. , Duarte A. P. 
Published: May 2007

AbstractDuring the last decade, the production of off‐season maize has increased in several regions of Brazil. Growing maize during this season, with sowing from January through April, imposes several climatic risks that can impact crop yield. This is mainly caused by the high variability of precipitation and the probability of frost during the reproduction phases. High production risks are also partially due to the use of cultivars that are not adapted to the local environmental conditions. The goal of this study was to evaluate crop growth and development and associated yield, yield components and water use efficiency (WUE) for maize hybrids with different maturity ratings grown off‐season in a subtropical environment under both rainfed and irrigated conditions. Three experiments were conducted in 2001 and 2002 in Piracicaba, state of São Paulo, Brazil with four hybrids of different maturity duration, AG9010 (very short season), DAS CO32 and Exceler (short season) and DKB 333B (normal season). Leaf area index (LAI), plant height and dry matter were measured approximately every 18 days. Under rainfed conditions, the soil water content in the deeper layers was reduced, suggesting that the extension of the roots into these layers was a response to soil water limitations. On average, WUE varied from 1.45 kg m−3 under rainfed conditions to 1.69 kg m−3 under irrigated conditions during 2001. The average yield varied from 4209 kg ha−1 for the hybrids grown under rainfed conditions to 5594 kg ha−1 under irrigated conditions during 2001. Yield reductions under rainfed conditions were affected by the genotype. For the hybrid DKB 333B with a normal maturity, yield was reduced by 25.6 % while the short maturity hybrid Exceler was the least impacted by soil water limitations with a yield reduction of only 8.4 %. To decrease the risk of yield loss, the application of supplemental irrigation should be considered by local farmers, provided that this practice is not restricted by either economic considerations or the availability of sufficient water resources.
Olfactory response of Trigonotylus caelestialium (Het.: Miridae) to rice plant and gramineous weeds
Authors: Niiyama T. , Fujii T. , Hori M. , Matsuda K. 
Published: May 2007

Abstract:  The olfactory response of Trigonotylus caelestialium, to rice, Oryza sativa L., and two species of gramineous weeds, Poa annua and Digitaria ciliaris, was investigated with an olfactometer to clarify the role of host‐plant odours as olfactory cues in their host‐finding behaviour. Third‐instar nymphs and adult males were significantly attracted to whole plants (above ground parts) of P. annua. However, adult females were not significantly attracted to whole plants of P. annua. Attractancy of rice to T. caelestialium differed with the growth stage and part of the plant. Adult females were significantly attracted to stems and leaves in the panicle‐formation stage, and panicles in the flowering stage. They were not attracted to stems and leaves in the fourth‐leaf stage and flowering stage, or to panicles in the milk‐and full‐ripe stages. Although adult males were significantly attracted to stems and leaves in the panicle‐formation stage, they were not attracted to the other rice structures tested. Both females and males were significantly attracted to stems and leaves, as well as panicles of D. ciliaris in the flowering stage. The findings suggest that T. caelestialium use host‐plant volatiles as olfactory cues to find their host plants and their invasion to paddy fields were caused by olfactory responses to rice plant.
Dystocia in a Rothschild Giraffe Leading to a Caesarean Section
Authors: Williams D. C. , Murison P. J. , Hill C. L. 
Published: May 2007

SummaryA 9‐year‐old female Rothschild giraffe (Giraffa camelopardalis rothschildi), weighing approximately 900 kg, at Longleat Safari Park, Wiltshire, UK was presented with dystocia in September 2005. This paper details the surgical and anaesthetic procedures carried out performing a caesarean section to remove a dead male calf and the successful recovery of the giraffe.
Factors Affecting the Success Rate of Treatment of Recumbent Dairy Cows Suffering from Hypocalcaemia
Authors: Gelfert C.‐C. , Alpers I. , Dallmeyer M. , Decker M. , Hüting A. , Lesch S. , Baumgartner W. , Staufenbiel R. 
Published: May 2007

SummaryWe aimed to investigate the ratio of accompanying diseases in cows suffering from clinical hypocalcaemia and their influence on cure rate. In five veterinary practices in different regions of Germany, all recumbent cows around parturition were included in the study for a period of 1 year. After recording the case history a clinical examination was done and a serum sample was taken to measure the concentrations of calcium and phosphorus magnesium, β‐hydroxybutyrate, total bilirubin, cholesterol, urea, and the activities of ASAT, CK, and GLDH. Only cows with hypocalcaemia entered the statistical analysis. Hypocalcaemia was the major cause of recumbency in cows of the second lactation or elder. Muscle damage was the second frequent diagnose in recumbent cows and the major concomitant disease in hypocalcaemic cows. The overall cure rate was between 89.4% and 94.8%. Calcium and phosphorus concentrations did not have an influence on cure rate. Non‐cured cows had higher serum activities of CK (p<0.043) and ASAT (p<0.006). Nevertheless, the activities of CK and ASAT were no good predictors of treatment failure because of their low specificity and the high cure rate of the cows in the five practices.
Patient handover from surgery to intensive care: using Formula 1 pit‐stop and aviation models to improve safety and quality
Authors: CATCHPOLE KEN R. , DE LEVAL MARC R. , MCEWAN ANGUS , PIGOTT NICK , ELLIOTT MARTIN J. , MCQUILLAN ANNETTE , MACDONALD CAROL , GOLDMAN ALLAN J. 
Published: May 2007

SummaryBackground:  We aimed to improve the quality and safety of handover of patients from surgery to intensive care using the analogy of a Formula 1 pit stop and expertise from aviation.Methods:  A prospective intervention study measured the change in performance before and after the implementation of a new handover protocol that was developed through detailed discussions with a Formula 1 racing team and aviation training captains. Fifty (23 before and 27 after) postsurgery patient handovers were observed. Technical errors and information omissions were measured using checklists, and teamwork was scored using a Likert scale. Duration of the handover was also measured.Results:  The mean number of technical errors was reduced from 5.42 (95% CI ±1.24) to 3.15 (95% CI ±0.71), the mean number of information handover omissions was reduced from 2.09 (95% CI ±1.14) to 1.07 (95% CI ±0.55), and duration of handover was reduced from 10.8 min (95% CI ±1.6) to 9.4 min (95% CI ±1.29). Nine out of twenty‐three (39%) precondition patients had more than one error in both technical and information handover prior to the new protocol, compared with three out of twnety‐seven (11.5%) with the new handover. Regression analysis showed that the number of technical errors were significantly reduced with the new handover (t = −3.63, P < 0.001), and an interaction suggested that teamwork (t = 3.04, P = 0.004) had a different effect with the new handover protocol.Conclusions:  The introduction of the new handover protocol lead to improvements in all aspects of the handover. Expertise from other industries can be extrapolated to improve patient safety, and in particular, areas of medicine involving the handover of patients or information.
The intraoperative use of recombinant FVIIa in child with hemophilia A with antibodies
Authors: SIMIC DUSICA , MILOJEVIC IRINA 
Published: May 2007

SummaryPatients with hemophilia A that developed inhibitors to FVIII represent a problem for bleeding control especially during surgical procedures. We report the use of bolus injections of rFVIIa during one intervention that included synoviectomy on the right knee, cholecystectomy and appendicectomy in a child with high titer of inhibitors to FVIII. rFVIIa was administered at the start (120 μg·kg−1) and then every 2 h (90 μg·kg−1) during the procedure. ε‐aminocapronic acid was also administered as an antifibrinolytic every 3 h. We monitored aPTT (activated partial thromboplastin time) and PT (prothrombin time) and they were within reference values. Surgery lasted 7 h without significant hemorrhage. Postoperatively the dose of rFVIIa was slowly reduced and after ten days the patient was discharged home in good condition. In our case rFVIIa helped a child with hemophilia A with antibodies to undergo major surgery but each case should be treated individually and the cost of rFVIIa has also to be taken into account.
Asymmetric Market Reactions of Growth and Value Firms with Management Earnings Forecasts*
Authors: Chan H. , Faff R. , Ho Y. K. , Ramsay A. 
Published: May 2007

ABSTRACTWe study the market reaction of Australian firms issuing management earnings forecasts (MEF). Specifically, we measure and distinguish between the immediate and post‐earnings announcement impact of MEF. Our analysis is conditioned on growth/value characteristics and news surprise and we test for asymmetric effects on these two conditioning variables. We find that the 3‐day returns following non‐routine bad news forecasts are significantly more negative for growth firms than value firms. No significant differences are found for good news forecasts. In the post‐earnings announcement period, both growth and value firms have significant negative post‐earnings announcement drift following non‐routine bad news forecasts but they are not significantly different from each other.
Effect of toe and heel elevation on calculated tendon strains in the horse and the influence of the proximal interphalangeal joint
Authors: Lawson Siân E. M. , Chateau Henry , Pourcelot Philippe , Denoix Jean‐Marie , Crevier‐Denoix Nathalie 
Published: May 2007

AbstractThe sagittal alteration of hoof balance is a common intervention in horses, with corrective shoeing being one of the most frequently applied methods of managing tendonitis. However, the effect of toe or heel elevation on tendon strains is poorly understood. This study aimed to examine the effect of toe and heel wedges on the superficial digital flexor tendon, deep digital flexor tendon, and the third interosseous muscle or suspensory ligament strains usingin vivodata and an accurate subject‐specific model. Kinematic data were recorded using invasive markers at the walk and trot. Computerized tomography was then used to create a subject‐specific model of an equine distal forelimb and strains were calculated for the superficial digital flexor tendon, the deep digital flexor tendon accessory ligament and the suspensory ligament for seven trials each of normal shoes, and toe and heel elevation. As the proximal interphalangeal joint is often ignored in strain calculations, its influence on the strain calculations was also tested. The deep ligament showed the same results for walk and trot with the heel wedge decreasing peak strain and the toe wedge increasing it. The opposite results were seen in the suspensory ligament and the superficial digital flexor tendon with the heel wedge increasing peak strain and the toe wedge decreasing it. The proximal interphalangeal joint was shown to be influential on the strains calculated with normal shoes and the calculated effect of the wedges. Our results imply that corrective shoeing appears to decrease strain in the tendon being targeted; the possibility of increases in strain in other structures should also be considered.
Human mesenchymal stem cells at the single‐cell level: simultaneous seven‐colour immunofluorescence
Authors: Schieker Matthias , Pautke Christoph , Haasters Florian , Schieker Jana , Docheva Denitsa , Böcker Wolfgang , Guelkan Huelya , Neth Peter , Jochum Marianne , Mutschler Wolf 
Published: May 2007

AbstractExtracellular, intracellular or surface proteins can be used as putative markers to characterize human mesenchymal stem cells (hMSC). However, these markers are also expressed by other cell types and primary cell pools reveal considerable heterogeneity. Therefore, the simultaneous detection of several markers on a single cell appears to be an attractive approach to identify hMSC. Here we demonstrate the specific distinction of human MSC from human osteoblasts via seven‐colour fluorescence on the single cell level with simultaneous marker detection of CD44, CD105/endoglin, CD106/VCAM‐1, collagen‐IV, fibronectin, actin and DAPI nuclear staining. We performed spectral image acquisition using a Sagnac‐type interferometer. Subsequent linear unmixing allowed for decomposition of each pixel in its spectral components. Our approach reveals a typical expression profile of the adherent singular cells, allowing the specific distinction between hMSC and osteoblasts on the single cell level.
Human TRP14 gene homologue from amphioxus Branchiostoma belcheri: identification, evolution, expression and functional characterization
Authors: Jiang Shengjuan , Zhang Shicui , Vuthiphandchai Verapong , Nimrat Subuntith 
Published: May 2007

AbstractThioredoxin‐related protein of 14 kDa, TRP14, has previously been identified only in humans. Here we report the identification and expression of an amphioxus TRP14 gene, named AmphiTRP14, the first such data in a non‐mammalian organism. AmphiTRP14 consists of a 372‐bp open reading frame coding for a 123‐amino‐acid protein with a calculated molecular weight of 14 kDa. It shares 56% identity with human TRP14 and possesses a highly conserved motif CPDC. Sequence comparison suggests the evolutionary appearance of the four‐exon‐three‐intron organization of TRP14 genes after the split of protostome/deuterostome, which is highly conserved since then. AmphiTRP14 has been successfully expressed in Escherichia coli and purified. The recombinant protein exhibited features characteristic of human TRP14, including a reductase activity towards insulin. Both in situ hybridization histochemistry and immunohistochemistry revealed that AmphiTRP14 was expressed in a tissue‐specific manner, with the most abundant expression in the hepatic caecum, ovary and hind‐gut. This suggests that AmphiTRP14 plays a fundamental but tissue‐specific role, or alternatively reflects differences in the tissue susceptibility to oxidative damage.
Polymorphic microsatellite DNA markers in the endangered land snail, Trichia caelata (Gastropoda, Stylommatophora)
Authors: ARMBRUSTER G. F. J. , ALVAREZ C. , PESARO M. , BAUR B. 
Published: May 2007

AbstractEight novel polymorphic microsatellite loci are presented for the endangered land snail Trichia caelata, a rare species endemic to the Northwestern Jura mountains, Switzerland. The number of alleles per locus ranged from six to 17. At seven loci, the expected heterozygosity differed significantly from observed heterozygosity. No evidence for linkage disequilibrium was detected between locus pairs. We are currently using these markers to investigate the genetic population structure of T. caelata in its restricted distribution area.