24 research outputs found

    Carotid Body AT4 Receptor Expression and its Upregulation in Chronic Hypoxia

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    Hypoxia regulates the local expression of angiotensin-generating system in the rat carotid body and the me-tabolite angiotensin IV (Ang IV) may be involved in the modulation of carotid body function. We tested the hypothesis that Ang IV-binding angiotensin AT4 receptors play a role in the adaptive change of the carotid body in hypoxia. The expression and localization of Ang IV-binding sites and AT4 receptors in the rat carotid bodies were studied with histochemistry. Specific fluorescein-labeled Ang IV binding sites and positive staining of AT4 immunoreactivity were mainly found in lobules in the carotid body. Double-labeling study showed the AT4 receptor was localized in glomus cells containing tyrosine hydroxylase, suggesting the expression in the chemosensitive cells. Intriguingly, the Ang IV-binding and AT4 immunoreactivity were more intense in the carotid body of chronically hypoxic (CH) rats (breathing 10% oxygen for 4 weeks) than the normoxic (Nx) control. Also, the protein level of AT4 receptor was doubled in the CH comparing with the Nx group, supporting an upregulation of the expression in hypoxia. To examine if Ang IV induces intracellular Ca2+ response in the carotid body, cytosolic calcium ([Ca2+]i) was measured by spectrofluorimetry in fura-2-loaded glomus cells dissociated from CH and Nx carotid bodies. Exogenous Ang IV elevated [Ca2+]i in the glomus cells and the Ang IV response was significantly greater in the CH than the Nx group. Hence, hypoxia induces an upregulation of the expression of AT4 receptors in the glomus cells of the carotid body with an increase in the Ang IV-induced [Ca2+]i elevation. This may be an additional pathway enhancing the Ang II action for the activation of chemoreflex in the hypoxic response during chronic hypoxia

    Maternal Postpartum Distress and Childhood Overweight

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    OBJECTIVE: We investigated associations between maternal postpartum distress covering anxiety, depression and stress and childhood overweight. METHODS: We performed a prospective cohort study, including 21,121 mother-child-dyads from the Danish National Birth Cohort (DNBC). Maternal distress was measured 6 months postpartum by 9 items covering anxiety, depression and stress. Outcome was childhood overweight at 7-years-of age. Multiple logistic regression analyses were performed and information on maternal age, socioeconomic status, pre-pregnancy BMI, gestational weight gain, parity, smoking during pregnancy, paternal BMI, birth weight, gestational age at birth, sex, breastfeeding and finally infant weight at 5 and 12 month were included in the analyses. RESULTS: We found, that postpartum distress was not associated with childhood risk of overweight, OR 1.00, 95%CI [0.98-1.02]. Neither was anxiety, depression, or stress exposure, separately. There were no significant differences between the genders. Adjustment for potential confounders did not alter the results. CONCLUSION: Maternal postpartum distress is apparently not an independent risk factor for childhood overweight at 7-years-of-age. However, we can confirm previous findings of perinatal determinants as high maternal pre-pregnancy BMI, and smoking during pregnancy being risk factors for childhood overweight

    Transcriptional Analysis of Fracture Healing and the Induction of Embryonic Stem Cell–Related Genes

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    Fractures are among the most common human traumas. Fracture healing represents a unique temporarily definable post-natal process in which to study the complex interactions of multiple molecular events that regulate endochondral skeletal tissue formation. Because of the regenerative nature of fracture healing, it is hypothesized that large numbers of post-natal stem cells are recruited and contribute to formation of the multiple cell lineages that contribute to this process. Bayesian modeling was used to generate the temporal profiles of the transcriptome during fracture healing. The temporal relationships between ontologies that are associated with various biologic, metabolic, and regulatory pathways were identified and related to developmental processes associated with skeletogenesis, vasculogenesis, and neurogenesis. The complement of all the expressed BMPs, Wnts, FGFs, and their receptors were related to the subsets of transcription factors that were concurrently expressed during fracture healing. We further defined during fracture healing the temporal patterns of expression for 174 of the 193 genes known to be associated with human genetic skeletal disorders. In order to identify the common regulatory features that might be present in stem cells that are recruited during fracture healing to other types of stem cells, we queried the transcriptome of fracture healing against that seen in embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs). Approximately 300 known genes that are preferentially expressed in ESCs and ∼350 of the known genes that are preferentially expressed in MSCs showed induction during fracture healing. Nanog, one of the central epigenetic regulators associated with ESC stem cell maintenance, was shown to be associated in multiple forms or bone repair as well as MSC differentiation. In summary, these data present the first temporal analysis of the transcriptome of an endochondral bone formation process that takes place during fracture healing. They show that neurogenesis as well as vasculogenesis are predominant components of skeletal tissue formation and suggest common pathways are shared between post-natal stem cells and those seen in ESCs

    Network Brand and Branding: A co-opetitive Approach to Local and Regional Development

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    Place branding debate is mostly based upon the assumption of a territorial competition that motivates a spreading interest for place branding and pushes cities and regions to build distinctive brands in order to position within competitors’ arena. However, this hegemonic assumption partially mirrors local and regional development policies, while increasing attention should be drawn to brand strategies crossing the borders of individual territorial units. This chapter explores network branding, which is defined as that process establishing a reputation, that is, an enduring perception of the network and its territorial partners and turning the network into an organizational identity. It is argued that network branding is based on co-opetitive rationale for economic development; coming from business studies, co-opetition refers to the benefits that organizations may receive from cooperating and competing with other organizations in value chains (including competitors) simultaneously. To what extent may place brand and branding give support to (and mirror) a territorial co-opetitive strategy? To what extent is network branding viable and sustainable in the framework of local and regional development policies? In an attempt to make an overview of key aspects and issues characterizing network branding, the chapter discusses the following points: (a) market-driven motivations according to which territorial competitive ethos drives cities and regions to seek collaboration in order to achieve a critical mass, cost-effectiveness, internationalization, and diversification; (b) political vision playing a role in shaping network brand strategies; network brands may, in fact, embody political ambitions and political discourse on development, as well as power games among the nodes (territorial units) of the network; (c) reputation building understood as image improvement, brand expansion, and rebranding in the space of the network, which adds brand layers to a complex brand architecture; (d) institutionalization of the branded network space into an accepted norm, an almost taken-for-granted entity, following the establishment of a platform for policy learning according to which an organizing and relational capacity is accumulated; and (e) risks and potential pitfalls of network branding strategies, such as citizens’ sense of irritation for an artificial region; managerial and technical challenges in managing a network brand in turbulent environments characterized by uncertainty and resources scarcity
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