94 research outputs found

    Intravesical Ty21a vaccine promotes dendritic cells and T cell-mediated tumor regression in the MB49 bladder cancer model

    Get PDF
    Preclinical data shows that intravesical instillation of Ty21a/Vivotif\uae, a commercial vaccine against typhoid fever, is an effective alternative option to standard Bacillus-Calmette-Gu\ue9rin (BCG) immunotherapy for nonmuscle-invasive bladder cancer (NMIBC). Here we characterized the inflammatory effects of Ty21a on the bladder and investigated the immune mechanisms underlying tumor-regression towards the use of this bacterial vaccine in NMIBC patients. MB49 bladder tumor-bearing mice had significantly improved survival after intravesical instillations of Ty21a doses of 106 to 108 colony-forming units. By immunohistochemistry and morphology, both BCG and Ty21a instillations were associated with bladder inflammation, which was decreased with the use of low, but effective, doses of Ty21a. Flow cytometry analysis showed a significant infiltration of T cells, natural killer (NK) cells, and myeloid cells, compared with controls, after a single dose of Ty21a, whereas this was only observed after multiple doses of BCG. The induced myeloid cells were predominantly neutrophils and Ly6C+CD103+ dendritic cells (DC), the latter being significantly more numerous after instillation of Ty21a than BCG. Ex vivo infection of human leukocytes with Ty21a, but not BCG, similarly significantly increased DC frequency. CD4+ and CD8+ T cells, but not NK cells nor neutrophils, were required for effective Ty21a bladder tumor responses. Thus, the generation of antitumor adaptive immunity was identified as a key process underlying Ty21a-mediated treatment efficacy. Altogether, these results demonstrate mechanisms of intravesical Ty21a therapy and suggest its potential as a safe and effective treatment for NMIBC patients

    Brain-Sparing Sympathofacilitators Mitigate Obesity without Adverse Cardiovascular Effects.

    Get PDF
    Anti-obesity drugs in the amphetamine (AMPH) class act in the brain to reduce appetite and increase locomotion. They are also characterized by adverse cardiovascular effects with origin that, despite absence of any in vivo evidence, is attributed to a direct sympathomimetic action in the heart. Here, we show that the cardiac side effects of AMPH originate from the brain and can be circumvented by PEGylation (PEGyAMPH) to exclude its central action. PEGyAMPH does not enter the brain and facilitates SNS activity via theβ2-adrenoceptor, protecting mice against obesity by increasing lipolysis and thermogenesis, coupled to higher heat dissipation, which acts as an energy sink to increase energy expenditure without altering food intake or locomotor activity. Thus, we provide proof-of-principle for a novel class of exclusively peripheral anti-obesity sympathofacilitators that are devoid of any cardiovascular and brain-related side effects

    pitx2 Deficiency Results in Abnormal Ocular and Craniofacial Development in Zebrafish

    Get PDF
    Human PITX2 mutations are associated with Axenfeld-Rieger syndrome, an autosomal-dominant developmental disorder that involves ocular anterior segment defects, dental hypoplasia, craniofacial dysmorphism and umbilical abnormalities. Characterization of the PITX2 pathway and identification of the mechanisms underlying the anomalies associated with PITX2 deficiency is important for better understanding of normal development and disease; studies of pitx2 function in animal models can facilitate these analyses. A knockdown of pitx2 in zebrafish was generated using a morpholino that targeted all known alternative transcripts of the pitx2 gene; morphant embryos generated with the pitx2ex4/5 splicing-blocking oligomer produced abnormal transcripts predicted to encode truncated pitx2 proteins lacking the third (recognition) helix of the DNA-binding homeodomain. The morphological phenotype of pitx2ex4/5 morphants included small head and eyes, jaw abnormalities and pericardial edema; lethality was observed at ∼6–8-dpf. Cartilage staining revealed a reduction in size and an abnormal shape/position of the elements of the mandibular and hyoid pharyngeal arches; the ceratobranchial arches were also decreased in size. Histological and marker analyses of the misshapen eyes of the pitx2ex4/5 morphants identified anterior segment dysgenesis and disordered hyaloid vasculature. In summary, we demonstrate that pitx2 is essential for proper eye and craniofacial development in zebrafish and, therefore, that PITX2/pitx2 function is conserved in vertebrates

    Teaching and learning in the clinical field: perspective of teachers, nurses and nursing students

    Get PDF
    This is a qualitative research, which used the social phenomenology of Alfred Schütz approach. Its purpose was meeting and discussing the expectations of teachers, nurses and students about teaching in the clinical field. Nine teachers, eleven nurses and eleven students of the Nursing Graduation grade from a public university of São Paulo were included in this study. Data were collected in 2012. As the results showed, there are expectations about the link between theory and practice that clinical teaching can offer and also the desire that such instruction enable the learners to develop a pro-active and participatory attitude. The reciprocity of perspectives was evident and should be considered when academic projects focused on nursing education are developed.Estudo qualitativo, com abordagem da fenomenologia social de Alfred Schütz, que teve como objetivo conhecer e discutir as expectativas dos docentes, enfermeiras e estudantes com relação ao ensino em campo clínico. Participaram do estudo nove docentes, 11 enfermeiras e 11 estudantes do Curso de Graduação em Enfermagem de uma universidade pública de São Paulo. A coleta dos dados foi realizada em 2012 e os resultados mostraram que os sujeitos esperam que o ensino clínico subsidie a articulação entre a teoria e a prática profissional; e almejam que tal ensino possibilite o desenvolvimento de uma postura próativa e participativa dos envolvidos na aprendizagem. A reciprocidade de perspectivas foi evidenciada, devendo ser considerada na elaboração de projetos pedagógicos voltados para a formação do enfermeiro

    Optogenetic Mimicry of the Transient Activation of Dopamine Neurons by Natural Reward Is Sufficient for Operant Reinforcement

    Get PDF
    Activation of dopamine receptors in forebrain regions, for minutes or longer, is known to be sufficient for positive reinforcement of stimuli and actions. However, the firing rate of dopamine neurons is increased for only about 200 milliseconds following natural reward events that are better than expected, a response which has been described as a “reward prediction error” (RPE). Although RPE drives reinforcement learning (RL) in computational models, it has not been possible to directly test whether the transient dopamine signal actually drives RL. Here we have performed optical stimulation of genetically targeted ventral tegmental area (VTA) dopamine neurons expressing Channelrhodopsin-2 (ChR2) in mice. We mimicked the transient activation of dopamine neurons that occurs in response to natural reward by applying a light pulse of 200 ms in VTA. When a single light pulse followed each self-initiated nose poke, it was sufficient in itself to cause operant reinforcement. Furthermore, when optical stimulation was delivered in separate sessions according to a predetermined pattern, it increased locomotion and contralateral rotations, behaviors that are known to result from activation of dopamine neurons. All three of the optically induced operant and locomotor behaviors were tightly correlated with the number of VTA dopamine neurons that expressed ChR2, providing additional evidence that the behavioral responses were caused by activation of dopamine neurons. These results provide strong evidence that the transient activation of dopamine neurons provides a functional reward signal that drives learning, in support of RL theories of dopamine function

    Unfertilized Xenopus Eggs Die by Bad-Dependent Apoptosis under the Control of Cdk1 and JNK

    Get PDF
    Ovulated eggs possess maternal apoptotic execution machinery that is inhibited for a limited time. The fertilized eggs switch off this time bomb whereas aged unfertilized eggs and parthenogenetically activated eggs fail to stop the timer and die. To investigate the nature of the molecular clock that triggers the egg decision of committing suicide, we introduce here Xenopus eggs as an in vivo system for studying the death of unfertilized eggs. We report that after ovulation, a number of eggs remains in the female body where they die by apoptosis. Similarly, ovulated unfertilized eggs recovered in the external medium die within 72 h. We showed that the death process depends on both cytochrome c release and caspase activation. The apoptotic machinery is turned on during meiotic maturation, before fertilization. The death pathway is independent of ERK but relies on activating Bad phosphorylation through the control of both kinases Cdk1 and JNK. In conclusion, the default fate of an unfertilized Xenopus egg is to die by a mitochondrial dependent apoptosis activated during meiotic maturation
    corecore