104 research outputs found

    Genetic Influences on Brain Gene Expression in Rats Selected for Tameness and Aggression

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    Inter-individual differences in many behaviors are partly due to genetic differences, but the identification of the genes and variants that influence behavior remains challenging. Here, we studied an F2 intercross of two outbred lines of rats selected for tame and aggressive behavior towards humans for more than 64 generations. By using a mapping approach that is able to identify genetic loci segregating within the lines, we identified four times more loci influencing tameness and aggression than by an approach that assumes fixation of causative alleles, suggesting that many causative loci were not driven to fixation by the selection. We used RNA sequencing in 150 F2 animals to identify hundreds of loci that influence brain gene expression. Several of these loci colocalize with tameness loci and may reflect the same genetic variants. Through analyses of correlations between allele effects on behavior and gene expression, differential expression between the tame and aggressive rat selection lines, and correlations between gene expression and tameness in F2 animals, we identify the genes Gltscr2, Lgi4, Zfp40 and Slc17a7 as candidate contributors to the strikingly different behavior of the tame and aggressive animals

    Expanding the genetic toolbox for the obligate human pathogen Streptococcus pyogenes

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    Genetic tools form the basis for the study of molecular mechanisms. Despite many recent advances in the field of genetic engineering in bacteria, genetic toolsets remain scarce for non-model organisms, such as the obligatory human pathogen Streptococcus pyogenes. To overcome this limitation and enable the straightforward investigation of gene functions in S. pyogenes, we have developed a comprehensive genetic toolset. By adapting and combining different tools previously applied in other Gram-positive bacteria, we have created new replicative and integrative plasmids for gene expression and genetic manipulation, constitutive and inducible promoters as well as fluorescence reporters for S. pyogenes. The new replicative plasmids feature low- and high-copy replicons combined with different resistance cassettes and a standardized multiple cloning site for rapid cloning procedures. We designed site-specific integrative plasmids and verified their integration by nanopore sequencing. To minimize the effect of plasmid integration on bacterial physiology, we screened publicly available RNA-sequencing datasets for transcriptionally silent sites. We validated this approach by designing the integrative plasmid pSpy0K6 targeting the transcriptionally silent gene SPy_1078. Analysis of the activity of different constitutive promoters indicated a wide variety of strengths, with the lactococcal promoter P23 showing the strongest activity and the synthetic promoter PxylS2 showing the weakest activity. Further, we assessed the functionality of three inducible regulatory elements including a zinc- and an IPTG-inducible promoter as well as an erythromycin-inducible riboswitch that showed low-to-no background expression and high inducibility. Additionally, we demonstrated the applicability of two codon-optimized fluorescent proteins, mNeongreen and mKate2, as reporters in S. pyogenes. We therefore adapted the chemically defined medium called RPMI4Spy that showed reduced autofluorescence and enabled efficient signal detection in plate reader assays and fluorescence microscopy. Finally, we developed a plasmid-based system for genome engineering in S. pyogenes featuring the counterselection marker pheS*, which enabled the scarless deletion of the sagB gene. This new toolbox simplifies previously laborious genetic manipulation procedures and lays the foundation for new methodologies to study gene functions in S. pyogenes, leading to a better understanding of its virulence mechanisms and physiology.Peer Reviewe

    Systematic reviews of complementary therapies - an annotated bibliography. Part 1: Acupuncture

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    Background Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with acupuncture. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of acupuncture; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pretested form and summarized descriptively. Results From a total of 48 potentially relevant reviews preselected in a screeening process 39 met the inclusion criteria. 22 were on various pain syndromes or rheumatic diseases. Other topics addressed by more than one review were addiction, nausea, asthma and tinnitus. Almost unanimously the reviews state that acupuncture trials include too few patients. Often included trials are heterogeneous regarding patients, interventions and outcome measures, are considered to have insufficient quality and contradictory results. Convincing evidence is available only for postoperative nausea, for which acupuncture appears to be of benefit, and smoking cessation, where acupuncture is no more effective than sham acupuncture. Conclusions A large number of systematic reviews on acupuncture exists. What is most obvious from these reviews is the need for (the funding of) well-designed, larger clinical trials

    Combined mRNA expression levels of members of the urokinase plasminogen activator (uPA) system correlate with disease-associated survival of soft-tissue sarcoma patients

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    <p>Abstract</p> <p>Background</p> <p>Members of the urokinase-type plasminogen activator (uPA) system are up-regulated in various solid malignant tumors. High antigen levels of uPA, its inhibitor PAI-1 and its receptor uPAR have recently been shown to be associated with poor prognosis in soft-tissue sarcoma (STS) patients. However, the mRNA expression of uPA system components has not yet been comprehensively investigated in STS patients.</p> <p>Methods</p> <p>The mRNA expression level of uPA, PAI-1, uPAR and an uPAR splice variant, uPAR-del4/5, was analyzed in tumor tissue from 78 STS patients by quantitative PCR.</p> <p>Results</p> <p>Elevated mRNA expression levels of PAI-1 and uPAR-del4/5 were significantly associated with clinical parameters such as histological subtype (<it>P </it>= 0.037 and <it>P </it>< 0.001, respectively) and higher tumor grade (<it>P </it>= 0.017 and <it>P </it>= 0.003, respectively). In addition, high uPAR-del4/5 mRNA values were significantly related to higher tumor stage of STS patients (<it>P </it>= 0.031). On the other hand, mRNA expression of uPA system components was not significantly associated with patients' survival. However, in STS patients with complete tumor resection (R0), high PAI-1 and uPAR-del4/5 mRNA levels were associated with a distinctly increased risk of tumor-related death (RR = 6.55, <it>P </it>= 0.054 and RR = 6.00, <it>P </it>= 0.088, respectively). Strikingly, R0 patients with both high PAI-1 and uPAR-del4/5 mRNA expression levels showed a significant, 19-fold increased risk of tumor-related death (<it>P </it>= 0.044) compared to the low expression group.</p> <p>Conclusion</p> <p>Our results suggest that PAI-1 and uPAR-del4/5 mRNA levels may add prognostic information in STS patients with R0 status and distinguish a subgroup of R0 patients with low PAI-1 and/or low uPAR-del4/5 values who have a better outcome compared to patients with high marker levels.</p

    EXACT EIGENVALUE DENSITIES AND THERMODYNAMIC PROPERTIES OF PERFECT QUANTUM GASES IN FINITE SYSTEMS

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    Il est donné un sommaire bref sur des densités exactes des valeurs propres de l'équation d'onde dans des domaines rectangulaires. A l'aide de ces densités de valeurs propres, l'énergie libre d'un gaz de photons est calculée et une formule d'interpolation de Debye généralisée est construite. Le domaine de taille et de température, dans lequel cette théorie améliorée peut être employée, est indiqué. La validité d'approximation T3 de Debye est discutée.A short review about exact eigenvalue densities of the wave equation in rectangular domains is given. With the aid of these eigenvalue densities the free energy of a photon gas bounded in one dimension is calculated and a generalized Debye interpolation formula for finite solids is constructed. The range of size and temperature is reported in which this improved theory may be used. The validity of the T3-law of the specific heat is discussed
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