bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct selection of Pichia pastoris expression strains using new G418 resistance vectors
Authors: Lin‐Cereghino Joan , Hashimoto Matthew D. , Moy Allison , Castelo James , Orazem Claire C. , Kuo Peter , Xiong See , Gandhi Vishal , Hatae Christopher T. , Chan Alex , Lin‐Cereghino Geoff P. 
Published: March 2008

AbstractThe methylotrophic yeast, Pichia pastoris, is widely used as a host organism for the expression of heterologous proteins. Currently, the Zeocin and blasticidin resistance genes are the only dominant selectable markers that can be used for primary selection of transformants. In this report we describe new expression vectors that can be used to select directly for P. pastoris transformants using G418 resistance conferred by a modified Tn903kanr gene. Compared to other dominant markers, this system is more economical and offers a higher transformation efficiency, due to the small sizes of the cloning vectors, pKAN B and pKANα B (GenBank Accession Nos EU285585 and EU285586, respectively). Additionally, multicopy transformants can be generated using these new vectors. Copyright © 2008 John Wiley & Sons, Ltd.
Bisimulations in calculi modelling membranes
Authors: Barbuti Roberto , Maggiolo-Schettini Andrea , Milazzo Paolo , Troina Angelo 
Published: March 2008

Abstract
Bisimulations are well-established behavioural equivalences that are widely used to study properties of computer science systems. Bisimulations assume the behaviour of systems to be described as labelled transition systems, and properties of a system can be verified by assessing its bisimilarity with a system one knows to enjoy those properties.
In this paper we show how semantics based on labelled transition systems and bisimulations can be defined for two formalisms for the description of biological systems, both capable of describing membrane interactions. These two formalisms are the Calculus of Looping Sequences (CLS) and Brane Calculi, and since they stem from two different approaches (rewrite systems and process calculi) bisimulation appears to be a good candidate as a general verification method.
We introduce CLS and define a labelled semantics and bisimulations for which we prove some congruence results. We show how bisimulations can be used to verify properties by way of two examples: the description of the regulation of lactose degradation in Escherichia coli and the description of the EGF signalling pathway. We recall the PEP calculus (the simplest of Brane Calculi) and its translation into CLS, we define a labelled semantics and some bisimulation congruences for PEP processes, and we prove that bisimilar PEP processes are translated into bisimilar CLS terms.
Researchers, Practitioners, and Funders: Using the Framework to Get Us on the Same Page
Authors: Emshoff James G. 
Published: March 2008

AbstractThe worlds of prevention research and practice are largely disconnected. The growing body of scientific knowledge regarding effects of prevention programs is not often disseminated and translated in a manner that leads to wide scale changes in practice. The Centers for Disease Control and Prevention, in collaboration with a team of academic researchers, has developed the Interactive Systems Framework for Dissemination and Implementation to help us understand the roles and interactions of those associated with developing knowledge, those associated with using the knowledge in practice settings, and those acting in the roles of bridge, support, and broker between the research and practice communities. This special issue on the Framework presents a variety of theoretical, practical and empirical issues related to this framework and its subsystems. This compilation of articles discuss the capacity of the Framework's subsystems, provide examples of the generally under‐developed prevention support system, describe the additional challenges involved in disseminating a change in culture, discuss the delicate balance and interaction of fidelity and adaptation, present a meta‐analysis of the relationships between program implementation and program outcomes, and include examples of how the Framework has been used to guide action. The present commentary on this special issue provides a critical examination of the contributions, implications, and challenges raised by each of these articles. It also includes a discussion of how the Framework relates to the basic values and practice of community psychology and concludes with some suggested future directions and challenges for the continued development and use of the Framework.
Does global warming induce segregation among alien and native beetle species in a mountain‐top?
Authors: Molina‐Montenegro Marco A. , Briones Raúl , Cavieres Lohengrin A. 
Published: March 2008

AbstractThe last few centuries have seen an increase in the mean air temperature of the planet, a phenomenon that is called “global warming”. One of the most sensitive habitats to the effects of global warming is the high‐elevation mountain environments, because these habitats are characterized by low temperature. Cushion plants are one of the best‐adapted growth forms in this habitat, generating more suitable sites for other plants and insects. In the present study, we experimentally evaluated the effects of global warming by open‐top chambers on the abundance and interaction of two ladybirds at 3,600 m, growing over cushions of the Azorella monantha species in the Andes of central Chile. Additionally, we measured variation in temperature, water content, and food availability by the presence of open‐top chambers as possible mechanisms of spatial segregation between ladybirds. Without open‐top chambers, the abundance of native and alien beetles was similar; but with open‐top chambers, the native beetle species is spatially segregated by alien species, decreasing in abundance. The open‐top chambers increase temperature and food availability, but not water content. We suggest that under the global warming scenario, the native insects will decrease in abundance or become extinct by the presence of alien insects, at least in the high‐elevation mountain environments.
Docosahexaenoic Acid is More Stable to Oxidation when Located at the sn‐2 Position of Triacylglycerol Compared to sn‐1(3)
Authors: Wijesundera Chakra , Ceccato Claudio , Watkins Peter , Fagan Peter , Fraser Benjamin , Thienthong Neeranat , Perlmutter Patrick 
Published: March 2008

AbstractRegio‐isomeric effects on the oxidative stability of triacylglycerols (TAG) containing docosahexaenoic acid (DHA) were investigated using two pairs of regio‐isomerically pure TAG, namely 1,3‐dihexadecanoyl‐2‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (PDP)/1,2‐dihexadecanoyl‐3‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (PPD) and 1,3‐dioctadecenoyl‐2‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (ODO)/1,2‐dioctadecenoyl‐3‐(4,7,10,13,16,19‐docosahexaenoyl)glycerol (OOD) where P, O, and D represent palmitic acid, oleic acid, and DHA respectively. Each pair of regio‐isomers was subjected to accelerated auto‐oxidation (at 40 or 50 °C inside a dark oven). In each case, the TAG oxidized more slowly when DHA was located at the sn‐2 position (PDP and ODO) compared to the sn‐1(3) position (PPD and OOD), as evidenced by slower development of peroxide value, slower depletion of DHA, and slower generation of secondary oxidation products propanal and trans, trans‐2,4‐heptadienal. The positional effect on auto‐oxidation was more pronounced when DHA occurred in combination with oleic acid than with palmitic acid.
Paramphistomum daubneyi: production dynamics and infectivity of metacercariae originating from snails dissected at regular intervals
Authors: Vignoles P. , Rondelaud D. , Dreyfuss G. 
Published: March 2008

AbstractExperimental infections of Galba truncatula with Paramphistomum daubneyi were carried out at 24°C to study the dynamics of larval development in snails dissected at regular intervals and to determine if metacercarial production might be improved. When the shell height of snails (4, 5, 6 or 7 mm) at exposure increased (experiment A), the total number of metacercariae was significantly higher in the 6- and 7-mm snails than in the other two groups, and the differentiation period was shortened (the first cercariae encysted at day 35 post-exposure (p.e.) instead of day 40 in the 4- and 5-mm groups). When the number of miracidia (two, three or five) for each 6-mm high G. truncatula increased (experiment B), a significant decrease of snail survival at day 30 p.e., a significant augmentation of prevalence, and a significant increase of metacercarial production were noted. In the two- and three-miracidium groups, the number of metacercariae was close to that found in the 6-mm snails from experiment 1, whereas they showed slower growth from day 45 to day 65 in the five-miracidium group. In the two groups of lambs infected with metacercariae encysted at days 45 or 60 p.e., no difference in the numbers of adult worms was noted. In contrast, in the case of 35-day encysted larvae, the number of adult worms was clearly lower. Snail dissection allowed higher metacercarial production, a saving of 12–15 days at 24°C to obtain these larvae, and a substantial decrease of their cost price for commercial production.
Rapid degradation of hypoxia‐inducible factor‐1α by KRH102053, a new activator of prolyl hydroxylase 2
Authors: Choi H J , Song B‐J , Gong Y‐D , Gwak W J , Soh Y 
Published: March 2008

Background and purpose: Hypoxia‐inducible factor (HIF) is a transcription factor induced by hypoxia and degraded by ubiquitin‐dependent proteasomes in normoxic conditions. Under hypoxic conditions, hydroxylation of HIF‐1α subunit by prolyl hydroxylase (PHD) is suppressed, thus leading to increased levels of HIF. Although PHD2 plays a key role in regulating the levels of HIF, chemical activators of PHD2 are relatively unknown. The aim of this study was to identify small molecule activators of PHD2 that could be used, eventually, to suppress the level of HIF‐1α.Experimental approach: By using the overproduced PHD2 as a target, a molecular library consisting of more than 600 small molecules with a benzopyran structure was screened with an HPLC assay method.Key results: We found a potent activator of PHD2, KRH102053 (2‐amino‐4‐methylsulphanyl‐butylic acid‐4‐methoxy‐6‐(4‐methoxy‐benzylamino)‐2,2‐dimethyl‐chroman‐3‐yl ester). The effects of KRH102053 on controlling HIF were studied in human HOS osteosarcoma, rat PC12 phaeochromocytoma and human HepG2 hepatoma cells. Under our experimental conditions, KRH102053 decreased the protein level of HIF‐1α and the mRNA levels of HIF‐regulated downstream target genes, such as vascular endothelial growth factor, aldolase A, enolase 1 and monocarboxylate transporter 4. Consistent with these results, KRH102053 also inhibited the rates of HIF‐related migration and invasion of HOS cells as well as the degree of tube formation in human umbilical vein endothelium cells.Conclusions and implications: These results suggest that KRH102053 and its structural analogues have the potential for use as therapeutic agents against various diseases associated with HIF.
Anti‐inflammatory effects of liquiritigenin as a consequence of the inhibition of NF‐κB‐dependent iNOS and proinflammatory cytokines production
Authors: Kim Y W , Zhao R J , Park S J , Lee J R , Cho I J , Yang C H , Kim S G , Kim S C 
Published: March 2008

Background and purpose: Glycyrrhizae radix has been widely used as a cytoprotective, plant‐derived medicine. We have identified a flavanoid, liquiritigenin, as an active component in extracts of Glycyrrhizae radix. This research investigated the effects of liquiritigenin on the induction of inducible NOS (iNOS) and proinflammatory cytokines by lipopolysaccharide (LPS) in Raw264.7 cells, and on paw oedema in rats.Experimental approach: iNOS expression was determined by western blotting, real‐time reverse transcription‐PCR and reporter gene analyses. Tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐1β and IL‐6 were assayed by ELISA. Gel shift assay and immunoblotting were used to assess NF‐κB activation. The effect of liquiritigenin on acute inflammation in vivo was evaluated using carrageenan‐induced paw oedema.Key results: Treatment of Raw264.7 cells with liquiritigenin caused inhibition of LPS‐induced NF‐κB DNA binding activity, due to repression of I‐κBα phosphorylation and degradation. Liquiritigenin treatment prevented LPS from increasing the levels of iNOS protein and mRNA in a concentration‐dependent manner. Liquiritigenin also suppressed the production of TNF‐α, IL‐1β and IL‐6 from Raw264.7 cells after LPS. In rats, liquiritigenin treatment inhibited formation of paw oedema induced by carrageenan.Conclusion and implications: These results demonstrate that liquiritigenin exerts anti‐inflammatory effects, which results from the inhibition of NF‐κB activation in macrophages, thereby decreasing production of iNOS and proinflammatory cytokines. Our findings showing inhibition by liquiritigenin of paw oedema as well as inflammatory gene induction will help to understand the pharmacology and mode of action of liquiritigenin, and of the anti‐inflammatory use of Glycyrrhizae radix.
Resveratrol protects against arsenic trioxide‐induced cardiotoxicity in vitro and in vivo
Authors: Zhao X‐Y , Li G‐Y , Liu Y , Chai L‐M , Chen J‐X , Zhang Y , Du Z‐M , Lu Y‐J , Yang B‐F 
Published: March 2008

Background and purpose: The clinical use of arsenic trioxide (As2O3), a potent antineoplastic agent, is limited by its severe cardiotoxic effects. QT interval prolongation and apoptosis have been implicated in the cardiotoxicity of As2O3. The present study was designed to evaluate the effects of resveratrol on As2O3‐induced apoptosis and cardiac injury.Experimental approach: In a mouse model of As2O3‐induced cardiomyopathy in vivo, QT intervals and plasma enzyme activities were measured; cardiac tissues were examined histologically and apoptosis assessed. In H9c2 cardiomyocyte cells, viability, apoptosis, generation of reactive oxygen species (ROS) and cellular calcium levels were measured.Key results: In the mouse model, resveratrol reduced As2O3‐induced QT interval prolongation and cardiomyocyte injury (apoptosis, myofibrillar loss and vacuolization). In addition, increased lactate dehydrogenase activity and decreased activities of glutathione peroxidase, catalase and superoxide dismutase were observed in the plasma of As2O3‐treated mice; these changes were prevented by pretreatment with resveratrol. In As2O3‐treated H9c2 cardiomyocytes, resveratrol significantly increased cardiomyocyte viability and attenuated cell apoptosis as measured by acridine orange/ethidium bromide staining, TdT‐mediated dUTP nick end labelling assay and caspase‐3 activity. As2O3‐induced generation of ROS and intracellular calcium mobilization in H9c2 cells was also suppressed by pretreatment with resveratrol.Conclusions and implications: Our results showed that resveratrol significantly attenuated As2O3‐induced QT prolongation, structural abnormalities and oxidative damage in the heart. In H9c2 cardiomyocytes, resveratrol also decreased apoptosis, production of ROS and intracellular calcium mobilization induced by treatment with As2O3. These observations suggested that resveratrol has the potential to protect against cardiotoxicity in As2O3‐exposed patients.
Activation of prostaglandin EP receptors by lubiprostone in rat and human stomach and colon
Authors: Bassil A K , Borman R A , Jarvie E M , McArthur‐Wilson R J , Thangiah R , Sung E Z H , Lee K , Sanger G J 
Published: March 2008

Background and purpose: Lubiprostone (Amitiza), a possible ClC‐2 channel opener derived from prostaglandin E1 and indicated for the treatment of constipation, increases chloride ion transport and fluid secretion into the intestinal lumen. As lubiprostone may also directly modulate gastrointestinal motility, we investigated its actions and the possible involvement of prostaglandin EP receptor activation on rat and human isolated gastrointestinal preparations.Experimental approach: Rat and human isolated preparations were mounted in tissue baths for isometric recording. The effects of lubiprostone on muscle tension and on electrically stimulated, neuronal contractions were investigated in the absence and presence of EP receptor antagonists.Key results: In rat and human stomach longitudinal muscle, lubiprostone induced a contraction (pEC50 of 7.0±0.0, n=4 and 6.4±0.2, n=3, respectively), which was inhibited by pretreatment with the EP1 receptor antagonist, EP1A 300 nM (pEC50 reduced to 6.2±0.2, n=6), but not by the EP3 or EP4 receptor antagonists (L‐798106 and GW627368X, respectively, 1 μM, P>0.05). Lubiprostone also reduced electrically stimulated, neuronal contractions in rat and human colon circular muscle preparations (pIC50 of 8.9±0.4, n=7 and 8.7±0.9, n=6, respectively), an effect mediated pre‐junctionally. This effect was reduced by the EP4 receptor antagonist (pIC50 of 6.7±1.1, n=7 and 7.7±0.4, n=6, respectively) but not by EP1 or EP3 receptor antagonists.Conclusions and implications: In rats and humans, lubiprostone contracts stomach longitudinal muscle and inhibits neuronally mediated contractions of colon circular muscle. Experiments are now needed to determine if this additional activity of lubiprostone contributes to its clinical efficacy and/or side‐effect profile.
KATP channel expression and pharmacological in vivo and in vitro studies of the KATP channel blocker PNU‐37883A in rat middle meningeal arteries
Authors: Ploug K B , Boni L J , Baun M , Hay‐Schmidt A , Olesen J , Jansen‐Olesen I 
Published: March 2008

Background and purpose: Dilatation of cerebral and dural arteries causes a throbbing, migraine‐like pain, indicating that these structures are involved in migraine.Clinical trials suggest that adenosine 5′‐triphosphate‐sensitive K+ (KATP) channel opening may cause migraine by dilatating intracranial arteries, including the middle meningeal artery (MMA). We studied the KATP channel expression profile in rat MMA and examined the potential inhibitory effects of the KATP channel blocker PNU‐37883A on KATP channel opener‐induced relaxation of the rat MMA, using the three KATP channel openers levcromakalim, pinacidil and P‐1075.Experimental approach: mRNA and protein expression of KATP channel subunits in the rat MMA were studied by quantitative real‐time PCR and western blotting, respectively. The in vivo and in vitro effects of the KATP channel drugs on rat MMA were studied in the genuine closed cranial window model and in myograph baths, respectively.Key results: Expression studies indicate that inwardly rectifying K+ (Kir)6.1/sulphonylurea receptor (SUR)2B is the major KATP channel complex in rat MMA. PNU‐37883A (0.5 mg kg−1) significantly inhibited the in vivo dilatory effect of levcromakalim (0.025 mg kg−1), pinacidil (0.38 mg kg−1) and P‐1075 (0.016 mg kg−1) in rat MMA. In vitro PNU‐37883A significantly inhibited the dilatory responses of the three KATP channel openers in rat MMA at 10−7 and 3 × 10−7 M.Conclusions and implications: We suggest that Kir6.1/SUR2B is the major functional KATP channel complex in the rat MMA. Furthermore, we demonstrate the potent in vivo and in vitro blocking potentials of PNU‐37883A on KATP channel opener‐induced relaxation of the rat MMA.
Azodisalicylate (Olsalazine) in the treatment of active ulcerative colitis. A placebo controlled clinical trial and assessment of drug disposition
Authors: HETZEL D. J. , SHEARMAN D. J. C. , BOCHNER F. , IMHOFF D. M. , GIBSON G. E. , FITCH R. J. , HECKER R. , LABROOY J. , ROWLAND R. 
Published: March 2008

Abstract The efficacy, safety and disposition of azodisalicylate, (ADS, Olsalazine) was assessed in patients with left‐sided ulcerative colitis (UC) or proctitis in a double‐blind placebo controlled trial. Thirty patients with a mild‐to‐moderate attack of UC were randomly allocated to ADS capsules 1 g (b.d.) or placebo for 6 weeks; other therapy was ceased. Patients were reviewed weekly and plasma, urine and faecal concentrations of ADS and its metabolites were determined by high performance liquid chromatography (HPLC). Sigmoidoscopy and biopsy were repeated at 6 weeks.Four patients receiving placebo and two receiving ADS were withdrawn because of diarrhoea. Five patients known to be allergic to sulphasalazine had no adverse reactions to ADS. Good clinical response was found in six patients receiving ADS and in two receiving placebo (P= 0.11). Improvement in sigmoidoscopic findings and histological appearance of rectal biopsies was also seen more frequently in ADS‐treated patients. Plasma concentrations of ADS were significantly higher in patients who improved. Faecal ADS, 5‐ASA and acetyl‐5‐ASA varied widely and showed no correlation with response. ADS showed an advantage over placebo which needs to be confirmed by further studies; it was safe in sulphasalazine‐sensitive patients but appeared to cause watery diarrhoea in two patients.
Serum procollagen‐III‐peptide in chronic hepatitis and schistosomiasis
Authors: ROBERTS F. D. , HALLIDAY J. W. , COOKSLEY W. G. E. , SANDFORD N. , KARAWI M. , SHAHED M. , MOHAMED A. , POWELL L. W. 
Published: March 2008

Abstract Recent reports have suggested that the serum concentration of procollagen‐III‐peptide (PPCP III) reliably reflects the degree of hepatic fibrosis but the topic remains controversial. Serum PPCP III levels have been measured in 40 patients with chronic hepatitis or schistosomiasis. In five patients both diseases were present. The relationship between serum PPCP III levels, hepatic fibrosis and disease activity have been studied histologically and biochemically. The mean serum concentration of PPCP III in patients with chronic hepatitis and in those with active liver disease was significantly higher than that in patients with inactive liver disease. In patients with chronic hepatitis only, serum PPCP III levels correlated with fibrosis, inflammation, and necrosis and also with the combined histological scores. When patients with schistosomiasis as well as hepatitis were included, significant correlations were still observed. In patients with schistosomiasis only, the serum PPCP III levels varied widely and did not correlate with disease activity or with the degree of inflammation, necrosis and fibrosis, either separately or combined. Serum PPCP III concentrations only correlated with serum aspartate amino transferase levels when the patient groups were combined. Serial measurements in 21 patients showed that PPCP III levels varied widely over a short period of time, and that these fluctuations did not significantly correlate with the respective changes in serum AST levels.In conclusion, serum PPCP III concentrations do not reliably reflect hepatic fibrosis, they are influenced by inflammation and activity of the disease, and they probably reflect the end result of the metabolic state of collagen in the liver, that is the combined effect of synthesis and degradation.