bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenosine A2A receptor antagonists: blockade of adenosinergic effects and T regulatory cells
Authors: Sitkovsky M , Lukashev D , Deaglio S , Dwyer K , Robson S C , Ohta A 
Published: March 2008

The intensity and duration of host responses are determined by protective mechanisms that control tissue injury by dampening down inflammation. Adenosine generation and consequent effects, mediated via A2A adenosine receptors (A2AR) on effector cells, play a critical role in the pathophysiological modulation of these responsesin vivo. Adenosine is both released by hypoxic cells/tissues and is also generated from extracellular nucleotides by ecto‐enzymes e.g. CD39 (ENTPD1) and CD73 that are expressed by the vasculature and immune cells, in particular by T regulatory cell. In general, these adenosinergic mechanisms minimize the extent of collateral damage to host tissues during the course of inflammatory reactions. However, induction of suppressive pathways might also cause escape of pathogens and permit dissemination. In addition, adenosinergic responses may inhibit immune responses while enhancing vascular angiogenic responses to malignant cells that promote tumor growth. Novel drugs that block A2AR‐adenosinergic effects and/or adenosine generation have the potential to boost pathogen destruction and to selectively destroy malignant tissues. In the latter instance, future treatment modalities might include novel ‘anti‐adenosinergic’ approaches that augment immune clearance of malignant cells and block permissive angiogenesis. This review addresses several possible pharmacological modalities to block adenosinergic pathways and speculates on their future application together with impacts on human disease.British Journal of Pharmacology(2008)153, S457–S464; doi:10.1038/bjp.2008.23
Modelling prefrontal cortex deficits in schizophrenia: implications for treatment
Authors: Pratt J A , Winchester C , Egerton A , Cochran S M , Morris B J 
Published: March 2008

Current treatments of schizophrenia are compromised by their inability to treat all symptoms of the disease and their side‐effects. Whilst existing antipsychotic drugs are effective against positive symptoms, they have negligible efficacy against the prefrontal cortex (PFC)‐associated cognitive deficits and negative symptoms. New models that reproduce core pathophysiological features of schizophrenia are more likely to have improved predictive validity in identifying new treatments. We have developed a NMDA receptor antagonist model that reproduces core PFC deficits of schizophrenia and discuss this in relation to pathophysiology and treatments. Subchronic and chronic intermittent PCP (2.6 mg/kg i.p.) was administered to rats. PFC activity was assessed by 2‐deoxyglucose imaging, parvalbumin and Kv3.1 mRNA expression, and the attentional set‐shifting test (ASST) of executive function. Affymetrix gene array technology was employed to examine gene expression profile patterns. PCP treatment reduced glucose utilization in the PFC (hypofrontality). This was accompanied by a reduction in markers of GABAergic interneurones (parvalbumin and Kv3.1 mRNA expression) and deficits in the extradimensional shift dimension of the ASST. Consistent with their clinical profile, the hypofrontality was not reversed by clozapine or haloperidol. Transcriptional analysis revealed patterns of change consistent with current neurobiological theories of schizophrenia. This model mirrors core neurobiological deficits of schizophrenia; hypofrontality, altered markers of GABAergic interneurone activity and deficits in executive function. As such it is likely to be a valuable translational model for understanding the neurobiological mechanisms underlying hypofrontality and for identifying and validating novel drug targets that may restore PFC deficits in schizophrenia.British Journal of Pharmacology (2008) 153, S465–S470; doi:10.1038/bjp.2008.24
Neuropharmacology of alcohol addiction
Authors: Vengeliene V , Bilbao A , Molander A , Spanagel R 
Published: March 2008

Despite the generally held view that alcohol is an unspecific pharmacological agent, recent molecular pharmacology studies demonstrated that alcohol has only a few known primary targets. These are the NMDA, GABAA, glycine, 5‐hydroxytryptamine 3 (serotonin) and nicotinic ACh receptors as well as L‐type Ca2+channels and G‐protein‐activated inwardly rectifying K+channels. Following this first hit of alcohol on specific targets in the brain, a second wave of indirect effects on a variety of neurotransmitter/neuropeptide systems is initiated that leads subsequently to the typical acute behavioural effects of alcohol, ranging from disinhibition to sedation and even hypnosis, with increasing concentrations of alcohol. Besides these acute pharmacodynamic aspects of alcohol, we discuss the neurochemical substrates that are involved in the initiation and maintenance phase of an alcohol drinking behaviour. Finally, addictive behaviour towards alcohol as measured by alcohol‐seeking and relapse behaviour is reviewed in the context of specific neurotransmitter/neuropeptide systems and their signalling pathways. The activity of the mesolimbic dopaminergic system plays a crucial role during the initiation phase of alcohol consumption. Following long‐term, chronic alcohol consumption virtually all brain neurotransmission seems to be affected, making it difficult to define which of the systems contributes the most to the transition from controlled to compulsive alcohol use. However, compulsive alcohol drinking is characterized by a decrease in the function of the reward neurocircuitry and a recruitment of antireward/stress mechanisms comes into place, with a hypertrophic corticotropin‐releasing factor system and a hyperfunctional glutamatergic system being the most important ones.British Journal of Pharmacology(2008)154, 299–315; doi:fn1; published online 3 March 2008
The neurocircuitry of addiction: an overview
Authors: Feltenstein M W , See R E 
Published: March 2008

Drug addiction presents as a chronic relapsing disorder characterized by persistent drug‐seeking and drug‐taking behaviours. Given the significant detrimental effects of this disease both socially and economically, a considerable amount of research has been dedicated to understanding a number of issues in addiction, including behavioural and neuropharmacological factors that contribute to the development, loss of control and persistence of compulsive addictive behaviours. In this review, we will give a broad overview of various theories of addiction, animal models of addiction and relapse, drugs of abuse, and the neurobiology of drug dependence and relapse. Although drugs of abuse possess diverse neuropharmacological profiles, activation of the mesocorticolimbic system, particularly the ventral tegmental area, nucleus accumbens, amygdala and prefrontal cortex via dopaminergic and glutamatergic pathways, constitutes a common pathway by which various drugs of abuse mediate their acute reinforcing effects. However, long‐term neuroadaptations in this circuitry likely underlie the transition to drug dependence and cycles of relapse. As further elucidated in more comprehensive reviews of various subtopics on addiction in later sections of this special issue, it is anticipated that continued basic neuroscience research will aid in the development of effective therapeutic interventions for the long‐term treatment of drug‐dependent individuals.British Journal of Pharmacology(2008)154, 261–274; doi:10.1038/bjp.2008.51; published online 3 March 2008
Short‐term or long‐term treatments with a phosphodiesterase‐4 (PDE4) inhibitor result in opposing agonist‐induced Ca2+ responses in endothelial cells
Authors: Campos‐Toimil M , Keravis T , Orallo F , Takeda K , Lugnier C 
Published: March 2008

Background and purpose: We previously reported that agonist‐induced rises in cytoplasmic Ca2+ concentration ([Ca2+]i) in human umbilical vein endothelial cells (HUVEC) were inhibited after a short‐term (2 min) pre‐treatment with cAMP‐elevating agents. The aim of this work was to study the effects of longer term (8 h) pre‐treatment with dibutyryl‐cAMP (db‐cAMP) or rolipram, a specific inhibitor of phosphodiesterase‐4 (PDE4), on [Ca2+]i, cAMP levels and PDE activity and expression in HUVEC.Experimental approach: [Ca2+]i changes were measured in isolated HUVEC by Fura‐2 imaging. Intracellular cAMP levels and PDE4 activity were assessed by enzyme‐immunoassay and radio‐enzymatic assay, respectively. PDE expression was measured by northern and western blot analysis.Key results: Long‐term pre‐treatment of HUVEC with rolipram or db‐cAMP significantly increased ATP‐, histamine‐ and thrombin‐induced [Ca2+]i rises. Short‐term pre‐treatment with rolipram was associated with an increase in cAMP, whereas long‐term pre‐treatment was associated with a decrease in cAMP. Long‐term pre‐treatment with rolipram or db‐cAMP induced a significant increase in PDE4 activity and the expression of 74 kDa‐PDE4A and 73 kDa‐PDE4B was specifically enhanced. All these effects were suppressed by cycloheximide.Conclusions and implications: Our data suggest that sustained inhibition of PDE4 by rolipram induced an increase in PDE4 activity, possibly as a compensatory mechanism to accelerate cAMP degradation and that PDE4A and PDE4B were implicated in the regulation of [Ca2+]i. Thus, isozyme‐specific PDE4 inhibitors might be useful as therapeutic agents in diseases where [Ca2+]i handling is altered, such as atherosclerosis, hypertension and tolerance to β‐adrenoceptor agonists.
Signalling pathways for transactivation by dexmedetomidine of epidermal growth factor receptors in astrocytes and its paracrine effect on neurons
Authors: Li B , Du T , Li H , Gu L , Zhang H , Huang J , Hertz L , Peng L 
Published: March 2008

Background and purpose: Stimulation of astrocytes by the α2‐adrenoceptor agonist dexmedetomidine, a neuroprotective drug, transactivates epidermal growth factor (EGF) receptors. The present study investigates signal pathways leading to release of an EGF receptor ligand and those activated during EGF receptor stimulation, and the response of neurons to dexmedetomidine and to astrocyte‐conditioned medium.Experimental approach: Phosphorylation of ERK1/2 was determined by western blotting and immunocytochemistry, and phosphorylation of EGF receptors by immunoprecipitation and western blotting. mRNA expression of fos family was measured by RT‐PCR.Key results: Pertussis toxin (0.2 μg ml−1) an inhibitor of βγ subunit dissociation from Gαi protein, and GF 109203X (500 nM), a protein kinase C inhibitor, abolished ERK1/2 phosphorylation. PP1 (10 μM), inhibiting Src kinase and GM 6001 (10 μM), an inhibitor of Zn‐dependent metalloproteinase, abolished ERK1/2 phosphorylation by dexmedetomidine (50 nM), but not that by EGF (10 ng ml−1), showing Src kinase and metalloproteinase activation during the first stage only; AG 1478 (1 μM), an inhibitor of the EGF receptor tyrosine kinase, abolished ERK1/2 phosphorylation. Dexmedetomidine‐induced EGF receptor phosphorylation was prevented by AG 1478, GM 6001, PP1 and GF 109203X and its induction of cfos and fosB by AG 1478 and by U0126 (10 μM), an inhibitor of ERK phosphorylation, indicating downstream effects of ERK1/2 phosphorylation. EGF and conditioned medium from dexmedetomidine‐treated astrocytes, but not dexmedetomidine itself, induced ERK phosphorylation in primary cultures of cerebellar neurons.Conclusions and implications: Dexmedetomidine‐induced transactivation pathways were delineated. Its paracrine effect on neurons may account for its neuroprotective effects.
Molecular epidemiology of clinically significant antibiotic resistance genes
Authors: Hawkey P M 
Published: March 2008

Antimicrobials were first introduced into medical practice a little over 60 years ago and since that time resistant strains of bacteria have arisen in response to the selective pressure of their use. This review uses the paradigm of the evolution and spread of beta‐lactamases and in particular beta‐lactamases active against antimicrobials used to treat Gram‐negative infections. The emergence and evolution particularly of CTX‐M extended‐spectrum beta‐lactamases (ESBLs) is described together with the molecular mechanisms responsible for both primary mutation and horizontal gene transfer. Reference is also made to other significant antibiotic resistance genes, resistance mechanisms in Gram‐negative bacteria, such as carbepenamases, and plasmid‐mediated fluoroquinolone resistance. The pathogen Staphylococcus aureus is reviewed in detail as an example of a highly successful Gram‐positive bacterial pathogen that has acquired and developed resistance to a wide range of antimicrobials. The role of selective pressures in the environment as well as the medical use of antimicrobials together with the interplay of various genetic mechanisms for horizontal gene transfer are considered in the concluding part of this review.British Journal of Pharmacology (2008) 153, S406–S413; doi:10.1038/sj.bjp.0707632
Seasonal and temporal trends in metrics of fish community for otter-trawl discards in a Mediterranean ecosystem
Authors: Tsagarakis K. , Machias A. , Giannoulaki M. , Somarakis S. , Karakassis I. 
Published: March 2008

Abstract
Tsagarakis, K., Machias, A., Giannoulaki, M., Somarakis, S., and Karakassis, I. 2008. Seasonal and temporal trends in metrics of fish community for otter-trawl discards in a Mediterranean ecosystem. – ICES Journal of Marine Science, 65: 539–550. Trends in discard to marketed ratios, size spectra, diversities, and trophic levels of the demersal fish community were examined using data from a seasonally closed commercial trawl fishery in the eastern Mediterranean Sea (Ionian Sea), over a period of about 10 years. Trends were also examined for the artificial fractions derived from the discarding process (the marketed, the discarded, and the non-marketed clusters of the catch), as well as for the “big” and “small” fractions (defined by the size at which 50% of all specimens were discarded). The ratio of the discarded/marketed catch fluctuated greatly. Two commercial (Merluccius merluccius, and Mullus barbatus) and two non-marketed species (Lepidotrigla cavillone, and Argentina sphyraena) were the characteristic species of the fractions. A declining trend with time was observed for the examined time-series for species richness (S), Margalef’s d, and average taxonomic distinctness (Δ+), whereas the variation in taxonomic distinctness (Λ+) increased. The composition and/or trophic level of discards in relation to the marketed catch seemed to be indicative of the exploitation state of the demersal community: differences between the discarded and marketed fractions were high at the beginning of the fishing season (autumn), but the values of the indices converged at the end of the fishing season (spring). These changes could be attributed to alternative discarding strategies for certain species in response to increased cumulative fishing mortality towards the end of the period.
Electroretinogram (ERG) Measurements in Larval Zebrafish
Authors: Fleisch Valerie C. , Jametti Tiziana , Neuhauss Stephan C.F. 
Published: March 2008

INTRODUCTIONThe electroretinogram (ERG) is an electrophysiological tool used to measure electrical activity originating in the outer retina in response to a light stimulus. Defects occurring at various levels of the retina can easily be detected by ERG measurements. Furthermore, the shape of the ERG response points toward the likely retinal cell type responsible for the deficit. Thus, this method is particularly useful for a rapid assessment of retinal function in genetically or pharmacologically manipulated animals. A typical ERG curve can be subdivided into three components: a small initial a-wave originating in photoreceptor activity, a large positive b-wave reflecting mainly ON bipolar cell depolarization, and a d-wave occurring at light offset. Here we present a noninvasive protocol for taking ERG measurements in larval zebrafish (4-7 days post-fertilization [dpf]). We use an extracellular recording electrode which is placed onto the surface of the cornea of the larva, and a light flash of a defined intensity and duration which is applied to evoke a response. In a typical larval ERG trace, we are able to record ERG a-, b-, and d-waves.
Methylated CpG Island Amplification and Microarray (MCAM) for High-Throughput Analysis of DNA Methylation
Authors: Estécio Marcos R. H. , Yan Pearlly S. , Huang Tim H-M. , Issa Jean-Pierre J. 
Published: March 2008

INTRODUCTIONThis protocol describes the use of methylated CpG island amplification (MCA) in combination with a microarray platform to analyze genome-wide DNA methylation in a high-throughput fashion. In this approach, termed MCAM, methylated CpG islands are selectively targeted using oligonucleotide adaptors after two rounds of digestion with a combination of methylation-sensitive and methylation-insensitive nucleases. They are then amplified using PCR. The resulting amplicons, representing the methylated fraction of the genome, are labeled with fluorochromes. Subsequently, a comparative hybridization of reference and test samples (typically normal and tumor DNA specimens) is done on a microarray platform.
Photoactivation Cell Labeling for Cell Tracing in Avian Development
Authors: Stark Danny A. , Kasemeier-Kulesa Jennifer C. , Kulesa Paul M. 
Published: March 2008

INTRODUCTIONTracing cell movements in a living embryo or embryo slice culture remains a challenging problem due to difficulties in cell accessibility and in accurate delivery of fluorescent labels into an individual cell or subgroup of cells. Here, we describe a photoactivation cell-labeling technique in avian embryos that allows for selective marking of individual cells or groups of cells at precise times and spatial locations normally not accessible using previous techniques. The current protocol is also less invasive than previously described methods. We provide details of fluorescent protein delivery into cells of interest utilizing microinjection and in ovo electroporation, as well as the optical parameters needed for photoactivation and imaging of both single- and dual-color photoactivatable fluorescent proteins (PAFPs). We present applications to label single cells and small subgroups of cells throughout the head and trunk of the developing vertebrate embryo, using the avian neural crest as our model cell population.
Transfection of HEK293-EBNA1 Cells in Suspension with 293fectin for Production of Recombinant Proteins
Authors: Tom Roseanne , Bisson Louis , Durocher Yves 
Published: March 2008

INTRODUCTIONFast and efficient production of recombinant proteins (r-proteins) remains a major challenge for the academic and biopharmaceutical communities. Pure r-proteins are often required in large amounts (hundreds of milligrams to gram quantities) when being developed as biotherapeutics, or in smaller quantities (milligrams) for high-throughput screening campaigns and structural or functional studies. Mammalian cells are often preferred over prokaryotic systems when expressing cDNAs of mammalian origin, due to their superior capability to conduct elaborate post-translational modifications. Large-scale transfection of mammalian cells is now establishing itself as a “must-have” technology in the scientific community, as it allows the production of milligram to gram quantities of r-proteins within a few days after cDNA cloning into the appropriate expression vector. Although calcium-mediated large-scale transfection is very effective, other methods suitable for efficient transfection of mammalian cells are easier to use. This protocol describes the steps needed for successful transfection of 293-6E cells in suspension culture in serum-free medium using 293fectin.
In vitro differentiation of Runx3−/–p53−/– gastric epithelial cells into intestinal type cells
Authors: Fukamachi Hiroshi , Mimata Ayako , Tanaka Issei , Ito Kosei , Ito Yoshiaki , Yuasa Yasuhito 
Published: March 2008

We have reported that a lack of RUNX3 function is causally associated with gastric carcinogenesis. We have also presented evidence that loss of Runx3 may be related to the genesis of intestinal metaplasia because expression of RUNX3 is reduced in some intestinal metaplasias, and some Runx3−/–p53−/– gastric epithelial cells differentiate into intestinal type cells in vivo. Recently several reports have indicated that blood cells play important roles in the gastric carcinogenesis. In the present study, we therefore examined whether Runx3−/–p53−/– gastric epithelial cells differentiate autonomously into intestinal type cells, or whether the presence of other cells is necessary for the differentiation in vitro. When Runx3−/–p53−/– gastric epithelial cells were cultured with collagen gels, they did not exhibit any morphogenesis and differentiated poorly. When cultured with fetal mouse gastric mesenchymes, the cells formed glandular structures and differentiated into surface mucous cells, but differentiation of intestinal type cells was never observed. When cultured with Matrigel, the cells formed glandular structures, and some cells differentiated into intestinal type cells in vitro. Reverse transcription–polymerase chain reaction analysis showed that the cells expressed stomach‐specific genes, and their levels decreased gradually during the culture. The cells expressed some intestine‐specific genes weakly at the start of culture, and their levels were increased with time in culture. We therefore conclude that Runx3−/–p53−/– gastric epithelial cells differentiate into intestinal type cells in combination with Matrigel in the absence of other cell types. Extracellular matrix, not blood cells, may play a role in the genesis of intestinal metaplasia. (Cancer Sci 2008; 99: 671–676)