102 research outputs found

    Cardiovascular effects of fentanyl in conscious rats

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    Abstract.: The polymicrobial sepsis induced by cecal ligation and puncture (CLP) in the rat is widely used in shock research. For ethical reasons, narcotic analgesics are often administered in this model, with the potential risk of confounding effects. In conscious non-septic rats, we investigated the cardiovascular effects of a continuous i.v. infusion of fentanyl (20”g/kg per h) administered with fluid loading (10ml/kg per h) for 24h, a regimen commonly applied in rat CLP. Animals were randomly allocated to receive analgesia with fluid loading (Fentanyl group), or fluid loading alone (Control). All endpoints were assessed after 24h of infusion. At that time, Control animals had mild respiratory alkalosis, which was essentially abolished by fentanyl. Analgesia mildly elevated the plasma norepinephrine levels [median (interquartile range): Control 232pg/ml (0-292), Fentanyl 302pg/ml (234-676), P=0.045] but was devoid of any effect on blood pressure, heart rate, cardiac output (mean ±SD: Control 388±61ml/kg per min, Fentanyl 382±62ml/kg per min, P=0.87) and indices of left ventricular function derived from high-fidelity recordings of left ventricular pressure (dP/dt max: Control 11782±2324mmHg/s, Fentanyl 12107±2816mmHg/s, P=0.77). In ex vivo experiments carried out immediately after animal sacrifice, no differences were noted between the Control and Fentanyl groups in the sensitivity of endothelium-intact aortic rings to norepinephrine-induced vasoconstriction (-logEC50: Control 8.78±0.28, Fentanyl 8.83±0.26, P=0.52) or acetylcholine-induced vasodilatation (-logEC50: Control 7.00±0.37, Fentanyl 7.06±0.26±0.53, P=0.75). In conclusion, the present data provide no contraindication, and even some support for the ethical use of a high dose i.v. infusion of fentanyl in cardiovascular studies of conscious catheterized rats undergoing CLP or other painful procedure

    Expressed sequence tags for genes: a review

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    Expressed sequence tags (ESTs) are partial sequences from the extremities of complementary DNA (CDNA) resulting from a single pass sequencing of clones from cDNA libraries, and different ESTs can be obtained from one gene. Sequence information from ESTs can be used for deciphering the function and the organisation of the genome. From a functional viewpoint, they allow the determination of the expression profiles of genes in any particular tissue, in different conditions or status, and thus the identification of regulated genes. In order to identify genes involved in particular processes one can select a specific group of mRNAs. For such a selection, classical techniques include subtraction or differential screening and new techniques, using polymerase chain reaction (PCR) amplification, are now available. For studies on the organisation of the genome the main use of ESTs is the determination of chromosomal localisation of the corresponding genes using a somatic hybrid cell panel. This chromosomal localisation information is needed to identify genes or quantitative trait loci, according to the ’positional candidate’ approach. ESTs also contribute to comparative genetics and they can help to decipher gene function by comparison between species, even genetically distant ones. Thus, combining sequence, functional and localisation data, ESTs contribute to an integrated approach to the genome.Les « Ă©tiquettes » correspondent aux sĂ©quences des extrĂ©mitĂ©s des ADN complĂ©mentaires, obtenues de maniĂšre systĂ©matique Ă  partir d’une seule rĂ©action de sĂ©quençage. Cependant, Ă  partir d’un seul gĂšne plusieurs Ă©tiquettes diffĂ©rentes peuvent ĂȘtre obtenues : celles qui correspondent aux deux extrĂ©mitĂ©s de l’ADN complĂ©mentaire, aux ADN complĂ©mentaires de tailles diffĂ©rentes synthĂ©tisĂ©s Ă  partir d’un mĂȘme ARN messager, et aux diffĂ©rents ARN messagers issus d’une mĂȘme sĂ©quence d’ADN gĂ©nomique. L’identification des gĂšnes correspondants est faite par comparaison avec les sĂ©quences nuclĂ©iques ou protĂ©iques contenues dans les bases de donnĂ©es publiques (GenBank ou EMBL, SwissProt), en utilisant des logiciels d’alignement automatique tels que FASTA ou BLAST. Les sĂ©quences annotĂ©es des Ă©tiquettes sont stockĂ©es dans une base de donnĂ©es particuliĂšre, dbEST, et soumises rĂ©guliĂšrement Ă  des tests de comparaison avec les bases de donnĂ©es citĂ©es. En raison de la prĂ©sence d’une longue rĂ©gion non codante Ă  l’extrĂ©mitĂ© 3’ des ARN messagers, les Ă©tiquettes de l’extrĂ©mitĂ© 3’ sont souvent non informatives. La comparaison des Ă©tiquettes entre elles permet d’essayer de regrouper celles qui peuvent appartenir Ă  un mĂȘme gĂšne et de dĂ©terminer ainsi une sĂ©quence consensus, plus longue et donc plus informative. Au niveau fonctionnel, les Ă©tiquettes permettent d’établir les profils d’expression des gĂšnes d’un tissu donnĂ© dans diffĂ©rentes situations physiologiques ou expĂ©rimentales et donc d’identifier les gĂšnes qui sont rĂ©gulĂ©s. Ces profils sont Ă©tablis en utilisant les Ă©tiquettes pour mesurer la frĂ©quence des diffĂ©rents ADNc dans une gĂ©nothĂšque prĂ©parĂ©e Ă  partir de ce tissu dans les diffĂ©rentes conditions Ă©tudiĂ©es. Dans une nouvelle stratĂ©gie, la SAGE (Serial Analysis of Gene expression), des Ă©tiquettes d’une dizaine de nuclĂ©otides sont collectĂ©es, mises bout Ă  bout et sĂ©quencĂ©es en sĂ©rie, ce qui permet d’accĂ©lĂ©rer l’acquisition de ces profils d’expression. Une autre approche est basĂ©e sur l’hybridation d’un grand nombre de clones dĂ©posĂ©s sur une mĂȘme membrane en nylon «filtres haute densitĂ© », ou, dans un format miniature, sur une lame de verre, « microarrays». Pour identifier les gĂšnes impliquĂ©s dans des processus bien dĂ©finis, diffĂ©rentes stratĂ©gies de soustraction ou de comparaison permettent de sĂ©lectionner une population particuliĂšre d’ARN messagers ; les techniques les plus rĂ©centes utilisent l’amplification par PCR. Au niveau de l’organisation du gĂ©nome, les Ă©tiquettes contribuent au dĂ©veloppement de la cartographie gĂ©nique : les gĂšnes correspondants sont localisĂ©s en utilisant un panel d’hybrides somatiques, les amorces nĂ©cessaires pour amplifier l’ADN des hybrides sont choisies grĂące aux informations de sĂ©quence fournies par les Ă©tiquettes. Cette information de localisation chromosomique est indispensable pour identifier les gĂšnes responsables des caractĂšres Ă©tudiĂ©s par une stratĂ©gie de gĂšne candidat positionnel. L’utilisation d’étiquettes d’une autre espĂšce peut Ă©galement permettre d’effectuer ces localisations et donc de dĂ©velopper des cartes comparĂ©es entre espĂšces qui mettent en Ă©vidence une certaine conservation de l’organisation des gĂšnes sur les chromosomes. Enfin, la conservation des gĂšnes n’est pas limitĂ©e Ă  la sĂ©quence et Ă  l’organisation : grĂące aux Ă©tiquettes, des analogies fonctionnelles de gĂšnes appartenant Ă  des espĂšces gĂ©nĂ©tiquement Ă©loignĂ©es ont Ă©tĂ© dĂ©crites et sont recherchĂ©es systĂ©matiquement pour identifier la fonction des gĂšnes. Ainsi, en permettant de combiner des donnĂ©es de sĂ©quence, d’expression et de localisation chromosomique, les Ă©tiquettes participent au dĂ©veloppement d’une approche intĂ©grĂ©e du gĂ©nome

    Part 2. Comparison of emergency washing solutions in 70% hydrofluoric acid-burned human skin in an established ex vivo explants model

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    Background: Hydrofluoric acid (HF) is a small and partially dissociated acid (pKa 3.2), able to deeply penetrate into human skin in addition to the corrosiveness of the hydrogen ion (H+) and the toxicity of the fluoride ion (F-). However, there has been a lack of experimental studies to objectively characterize the results of human HF skin exposure decontamination

    The impact of oxygen on the transcriptome of recombinant S. cerevisiae and P. pastoris - a comparative analysis

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    Background: Saccharomyces cerevisiae and Pichia pastoris are two of the most relevant microbial eukaryotic platforms for the production of recombinant proteins. Their known genome sequences enabled several transcriptomic profiling studies under many different environmental conditions, thus mimicking not only perturbations and adaptations which occur in their natural surroundings, but also in industrial processes. Notably, the majority of such transcriptome analyses were performed using non-engineered strains. In this comparative study, the gene expression profiles of S. cerevisiae and P. pastoris, a Crabtree positive and Crabtree negative yeast, respectively, were analyzed for three different oxygenation conditions (normoxic, oxygen-limited and hypoxic) under recombinant protein producing conditions in chemostat cultivations. Results: The major differences in the transcriptomes of S. cerevisiae and P. pastoris were observed between hypoxic and normoxic conditions, where the availability of oxygen strongly affected ergosterol biosynthesis, central carbon metabolism and stress responses, particularly the unfolded protein response. Steady state conditions under low oxygen set-points seemed to perturb the transcriptome of S. cerevisiae to a much lesser extent than the one of P. pastoris, reflecting the major tolerance of the baker's yeast towards oxygen limitation, and a higher fermentative capacity. Further important differences were related to Fab production, which was not significantly affected by oxygen availability in S. cerevisiae, while a clear productivity increase had been previously reported for hypoxically grown P. pastoris. Conclusions: The effect of three different levels of oxygen availability on the physiology of P. pastoris and S. cerevisiae revealed a very distinct remodelling of the transcriptional program, leading to novel insights into the different adaptive responses of Crabtree negative and positive yeasts to oxygen availability. Moreover, the application of such comparative genomic studies to recombinant hosts grown in different environments might lead to the identification of key factors for efficient protein production

    Genetic Diversity of EBV-Encoded LMP1 in the Swiss HIV Cohort Study and Implication for NF-Κb Activation

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    Epstein-Barr virus (EBV) is associated with several types of cancers including Hodgkin's lymphoma (HL) and nasopharyngeal carcinoma (NPC). EBV-encoded latent membrane protein 1 (LMP1), a multifunctional oncoprotein, is a powerful activator of the transcription factor NF-ÎșB, a property that is essential for EBV-transformed lymphoblastoid cell survival. Previous studies reported LMP1 sequence variations and induction of higher NF-ÎșB activation levels compared to the prototype B95-8 LMP1 by some variants. Here we used biopsies of EBV-associated cancers and blood of individuals included in the Swiss HIV Cohort Study (SHCS) to analyze LMP1 genetic diversity and impact of sequence variations on LMP1-mediated NF-ÎșB activation potential. We found that a number of variants mediate higher NF-ÎșB activation levels when compared to B95-8 LMP1 and mapped three single polymorphisms responsible for this phenotype: F106Y, I124V and F144I. F106Y was present in all LMP1 isolated in this study and its effect was variant dependent, suggesting that it was modulated by other polymorphisms. The two polymorphisms I124V and F144I were present in distinct phylogenetic groups and were linked with other specific polymorphisms nearby, I152L and D150A/L151I, respectively. The two sets of polymorphisms, I124V/I152L and F144I/D150A/L151I, which were markers of increased NF-ÎșB activation in vitro, were not associated with EBV-associated HL in the SHCS. Taken together these results highlighted the importance of single polymorphisms for the modulation of LMP1 signaling activity and demonstrated that several groups of LMP1 variants, through distinct mutational paths, mediated enhanced NF-ÎșB activation levels compared to B95-8 LMP1

    Tuberculosis in Pediatric Antiretroviral Therapy Programs in Low- and Middle-Income Countries: Diagnosis and Screening Practices

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    Background The global burden of childhood tuberculosis (TB) is estimated to be 0.5 million new cases per year. Human immunodeficiency virus (HIV)-infected children are at high risk for TB. Diagnosis of TB in HIV-infected children remains a major challenge. Methods We describe TB diagnosis and screening practices of pediatric antiretroviral treatment (ART) programs in Africa, Asia, the Caribbean, and Central and South America. We used web-based questionnaires to collect data on ART programs and patients seen from March to July 2012. Forty-three ART programs treating children in 23 countries participated in the study. Results Sputum microscopy and chest Radiograph were available at all programs, mycobacterial culture in 40 (93%) sites, gastric aspiration in 27 (63%), induced sputum in 23 (54%), and Xpert MTB/RIF in 16 (37%) sites. Screening practices to exclude active TB before starting ART included contact history in 41 sites (84%), symptom screening in 38 (88%), and chest Radiograph in 34 sites (79%). The use of diagnostic tools was examined among 146 children diagnosed with TB during the study period. Chest Radiograph was used in 125 (86%) children, sputum microscopy in 76 (52%), induced sputum microscopy in 38 (26%), gastric aspirate microscopy in 35 (24%), culture in 25 (17%), and Xpert MTB/RIF in 11 (8%) children. Conclusions Induced sputum and Xpert MTB/RIF were infrequently available to diagnose childhood TB, and screening was largely based on symptom identification. There is an urgent need to improve the capacity of ART programs in low- and middle-income countries to exclude and diagnose TB in HIV-infected childre

    Analysis of shared heritability in common disorders of the brain

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    ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders
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