168 research outputs found
Differentiation of cerebellar cell identities in absence of Fgf signalling in zebrafish Otx morphants
Although the secreted molecule Fgf8 is a key player of the isthmic organiser function, the mechanisms by which it acts remain unclear. Here, we present evidence indicating that Fgf8 is not instructive in establishing zebrafish cerebellar cell identities, although it is required for proliferation and morphogenesis of this territory. We first show that, as in mouse, lack of Otx function in zebrafish leads to transformation of the presumptive mesencephalon into an extended rhombomere 1 (r1). Expanded Fgf8 expression was proposed to be the cause of this fate transformation. However, this report demonstrates that zebrafish embryos lacking both Otx and fgf8 functions retain an extended r1 and display differentiation of at least two cerebellar cell fates. We show that this is not caused by presence of other Fgfs, which implies that in absence of Otx, Fgf function is not necessary for the differentiation of cerebellar cell types. Otx proteins are therefore potent repressors of cerebellar fates, kept out of r1 progeny by Fgf8. Because Otx transcripts are not present in presumptive r1 territory prior to fgf8 expression, Fgf8 is required to maintain, rather than induce, the posterior boundary of Otx expression. This maintenance is enough to allow cerebellar differentiatio
Development of an innovative adenovirus-inspired self-assembling vaccine platform rapidly adaptable to coronaviruses and other emergent viruses
The COVID-19 pandemic clearly shows how emergent diseases can cause severe global health and economic problems. We must be prepared to react swiftly against new pathogenic agents and this requires the development of vaccines that are safe, efficient in the long-term and easily adaptable with a short revision time. To this end, the COVID-19 mRNA and adenoviral vector vaccines have been spectacular successes, permitting rapid vaccination across the world in an unprecedented manner. Here we report the design of a new adenovirus-derived vaccine technology based on non-infectious pseudo-viral nanoparticles from the serotype 3 human adenovirus. Each nanoparticle comprises sixty identical proteins that assemble to form a 30 nm diameter spherical particle. A sequence has been engineered into the surface of this protein that enables the display of a covalently-bound target antigens. To demonstrate the efficiency of this approach, we added the SARS-CoV 2 spike protein receptor binding domain (RBD), that interacts with host cell ACE2 receptors, to the surface of the nanoparticles. We first showed that the glycosylated RBD retained its ACE2-binding function when displayed on nanoparticles. We then measured the in vivo humoral response of our vaccine candidate in mice and observed a strong antibody response after the prime injection; further levels were achieved following a second booster injection. In mice preimmunized with underivatized adenoviral nanoparticles, we tested if adenovirus seroprevalence, as frequently observed in humans, was detrimental to the RBD-mediated protection provided by our vaccine candidate. Interestingly, a strong anti-coronaviral response was still observed suggesting that existing circulating anti-adenovirus antibodies are not deleterious to our vaccine platform. We then performed pseudo-CoV 2 neutralization assays and obtained higher ID50 values than observed with COVID-19 convalescent sera, thus showing the high potential efficacy of our vaccine platform. This new vaccine technology is a tool that is easily adaptable to future SARS-CoV 2 variants and, more generally, to future emergent viruses and pathogens
Interaction of C1q With Pentraxin 3 and IgM Revisited: Mutational Studies With Recombinant C1q Variants
Pentraxins and complement defense collagens are soluble recognition proteins that sense pathogens and altered-self elements, and trigger immune responses including complement activation. PTX3 has been shown to interact with the globular recognition domains (gC1q) of the C1q protein of the classical complement pathway, thereby modulating complement activity. The C1q-PTX3 interaction has been characterized previously by site-specific mutagenesis using individual gC1q domains of each of the three C1q chains. The present study is aimed at revisiting this knowledge taking advantage of full-length recombinant C1q. Four mutations targeting exposed amino acid residues in the gC1q domain of each of the C1q chains (LysA200Asp-LysA201Asp, ArgB108Asp-ArgB109Glu, TyrB175Leu, and LysC170Glu) were introduced in recombinant C1q and the interaction properties of the mutants were analyzed using surface plasmon resonance. All C1q mutants retained binding to C1r and C1s proteases and mannose-binding lectin-associated serine proteases, indicating that the mutations did not affect the function of the collagen-like regions of C1q. The effect of these mutations on the interaction of C1q with PTX3 and IgM, and both the PTX3- and IgM-mediated activation of the classical complement pathway were investigated. The LysA200Asp-LysA201Asp and LysC170Glu mutants retained partial interaction with PTX3 and IgM, however they triggered efficient complement activation. In contrast, the ArgB108Asp-ArgB109Glu mutation abolished C1q binding to PTX3 and IgM, and significantly decreased complement activation. The TyrB175Leu mutant exhibited decreased PTX3- and IgM-dependent complement activation. Therefore, we provided evidence that, in the context of the full length C1q protein, a key contribution to the interaction with both PTX3 and IgM is given by the B chain Arg residues that line the side of the gC1q heterotrimer, with a minor participation of a Lys residue located at the apex of gC1q. Furthermore, we generated recombinant forms of the human PTX3 protein bearing either D or A at position 48, a polymorphic site of clinical relevance in a number of infections, and observed that both allelic variants equally recognized C1q
Smoking Cessation Counselling: What Makes Her or Him a Good Counsellor? Can Counselling Technique Be Deduced to Other Important Lifestyle Counselling Competencies?
Smoking is a major health concern in both developed and developing countries. Smoking cessation counselling is of major importance for health care providers such as physicians, psychologists, nurses and many further therapeutic workers. We recently have demonstrated feasibility of a 4-hour “student-to-student course” (1 hour of scientific background and 3 hours of role plays and intervision) that provided knowledge, skills and attitude to smoking cessation counselling. A key question remains whether such knowledge, skills and attitude can be further deduced to key public health or lifestyle counselling areas like body weight management in overweight persons, management of addictions like alcohol and substance or situation (e.g., Internet and shopping) abuse, management of physical activity/exercise or lifestyle modification like workaholic lifestyle. The authors try to develop such a base for enabling patients to adapt healthier behaviour and give objectives for such counselling situations including the elaboration of clear therapeutic aims for counsellors
Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel
Target-agnostic identification of human antibodies to Plasmodium falciparum sexual forms reveals cross-stage recognition of glutamate-rich repeats
Circulating sexual stages of Plasmodium falciparum (Pf) can be transmitted from humans to mosquitoes, thereby furthering the spread of malaria in the population. It is well established that antibodies can efficiently block parasite transmission. In search for naturally acquired antibodies targets on sexual stages, we established an efficient method for target-agnostic single B cell activation followed by high-throughput selection of human monoclonal antibodies (mAbs) reactive to sexual stages of Pf in the form of gametes and gametocyte extracts. We isolated mAbs reactive against a range of Pf proteins including well-established targets Pfs48/45 and Pfs230. One mAb, B1E11K, was cross-reactive to various proteins containing glutamate-rich repetitive elements expressed at different stages of the parasite life cycle. A crystal structure of two B1E11K Fab domains in complex with its main antigen, RESA, expressed on asexual blood stages, showed binding of B1E11K to a repeating epitope motif in a head-to-head conformation engaging in affinity-matured homotypic interactions. Thus, this mode of recognition of Pf proteins, previously described only for Pf circumsporozoite protein (PfCSP), extends to other repeats expressed across various stages. The findings augment our understanding of immune-pathogen interactions to repeating elements of the Plasmodium parasite proteome and underscore the potential of the novel mAb identification method used to provide new insights into the natural humoral immune response against Pf
Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at √s=7 TeV
Charged-hadron transverse-momentum and pseudorapidity distributions in proton-proton collisions at root s = 7 TeV are measured with the inner tracking system of the CMS detector at the LHC. The charged-hadron yield is obtained by counting the number of reconstructed hits, hit pairs, and fully reconstructed charged-particle tracks. The combination of the three methods gives a charged-particle multiplicity per unit of pseudorapidity dN(ch)/d eta vertical bar(vertical bar eta vertical bar<0.5) = 5.78 +/- 0.01(stat) +/- 0.23(stat) for non-single-diffractive events, higher than predicted by commonly used models. The relative increase in charged-particle multiplicity from root s = 0.9 to 7 TeV is [66.1 +/- 1.0(stat) +/- 4.2(syst)]%. The mean transverse momentum is measured to be 0.545 +/- 0.005(stat) +/- 0.015(syst) GeV/c. The results are compared with similar measurements at lower energies
Being treated in higher volume hospitals leads to longer progression-free survival for epithelial ovarian carcinoma patients in the Rhone-Alpes region of France
Recovery: Ein Konzept für die Soziale Arbeit in der Psychiatrie?: Eine Forschungsarbeit über die Bedeutung von Recovery als Konzept in der Sozialen Arbeit in der Zentralschweizer Psychiatrie
Die vorliegende Forschungsarbeit untersucht, in welchem Ausmass in den Zentralschweizer Sozialpsychiatrien das Recovery-Konzept von Mitarbeitenden der Sozialen Arbeit angewendet wird. Die Autorinnen haben dieses Konzept in der Praxis der Sozialen Arbeit kennen gelernt und interessieren sich für vertiefte Nachforschungen in diesem Bereich. Die Forschungsfrage lautet: «Wie recovery-orientiert arbeitet die Soziale Arbeit in der Zentralschweizer Sozialpsychiatrie?». Mit der Durchführung und Auswertung einer Interviewstudie haben die Autorinnen diese Leitfrage zu beantworten versucht. Vier weitere Frageaspekte, die sich mit Rückgriff auf theoretische Überlegungen und mithilfe der Auswertung institutioneller Leitbilder beantworten lassen, sind in der Arbeit handlungsleitend. Alle Fragestellungen beziehen sich auf das Recovery-Konzept, die Werthaltungen und die Gesundheitsförderung. Im Theorieteil wird das Recovery-Konzept beschrieben. Da das in der Praxis entstandene Konzept einer einzigen, umfassenden Theorie entbehrt, wurden die ethischen Prinzipien der Sozialen Arbeit, das lösungsorientierte Arbeiten, das Empowerment, die Partizipation, die Salutogenese nach Aaron Antonovsky und die Alltags- und Lebensweltorientierung nach Hans Thiersch als theoretische Zugänge gewählt. Im Methodenteil werden die Wahl der Methoden und der Stichprobe eingehend begründet und das Forschungsdesign beschrieben. Die Autorinnen haben zwölf Experteninterviews durchgeführt. Alle Befragten sind professionelle Sozialarbeitende, die in ambulanten oder stationären zentralschweizerischen Sozialpsychiatrien arbeiten. Die Hälfte der interviewten Personen ist der Ansicht, dass ihre Institution recovery-orientiert arbeitet. Vier Personen denken, dass ihre Institution teilweise recovery-orientiert arbeitet und zwei konnten ihre Institution bezüglich dieses Aspekts nicht bewerten.Die Autorinnen befinden, dass der Grossteil der Institutionen eine recovery-orientierte Herangehens- und Arbeitsweise hat. Jedoch wird das Potenzial der Recovery-Perspektive, insbesondere bei der Förderung von Hoffnung, Zuversicht und Optimismus, aus Sicht der Autorinnen noch nicht gezielt ausgeschöpft
Notch signaling blockade links transcriptome heterogeneity in quiescent neural stem cells with their reactivation routes and potential
In the vertebrate brain, neural stem cell (NSC) quiescence is necessary for stemness maintenance. Using single cell RNA sequencing (scRNAseq) in the zebrafish adult telencephalon, we identified different molecular clusters of quiescent NSCs, interpreted to sign different quiescence depths( 1 ). Here, we show that these clusters, when challenged in vivo with an inhibitor of Notch signaling -a major quiescence promoting pathway-, unfold different behaviors. Notably, deeply quiescent NSCs with astrocytic features display a unique activation phenotype that combines the maintenance of astrocytic markers with the rapid upregulation of activation and neuronal commitment genes, reminiscent to murine periventricular astrocytes activating upon lesion. In contrast, an NSC cluster predicted to be in the deepest quiescence state resists Notch blockade, and we demonstrate that the transcription factor Nr2f1b mediates this resistance to activation in vivo . These results together link the molecular heterogeneity of quiescent NSCs with bona fide biological properties and their molecular regulators
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