10 research outputs found

    c-kitpos GATA-4 High Rat Cardiac Stem Cells Foster Adult Cardiomyocyte Survival through IGF-1 Paracrine Signalling

    Get PDF
    Resident c-kit positive (c-kitpos) cardiac stem cells (CSCs) could be considered the most appropriate cell type for myocardial regeneration therapies. However, much is still unknown regarding their biological properties and potential.We produced clones of high and low expressing GATA-4 CSCs from long-term bulk-cultured c-kitpos CSCs isolated from adult rat hearts. When c-kitpos GATA-4 high expressing clonal CSCs (cCSCs) were co-cultured with adult rat ventricular cardiomyocytes, we observed increased survival and contractility of the cardiomyocytes, compared to cardiomyocytes cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low expressing cCSCs. When analysed by ELISA, the concentration of IGF-1 was significantly increased in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-cultures and there was a significant correlation between IGF-1 concentration and cardiomyocyte survival. We showed the activation of the IGF-1 receptor and its downstream molecular targets in cardiomyocytes co-cultured with c-kitpos GATA-4 high cCSCs but not in cardiomyocytes that were cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low cCSCs. Addition of a blocking antibody specific to the IGF-1 receptor inhibited the survival of cardiomyocytes and prevented the activation of its signalling in cardiomyocytes in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-culture system. IGF-1 supplementation or IGF-1 high conditioned medium taken from the co-culture of c-kitpos GATA-4 high cCSCs plus cardiomyocytes did extend the survival and contractility of cardiomyocytes cultured alone and cardiomyocytes co-cultured with c-kitpos GATA-4 low cCSCs.c-kitpos GATA-4 high cCSCs exert a paracrine survival effect on cardiomyocytes through induction of the IGF-1R and signalling pathway

    Global Warming and Endocrinology: The Hyderabad Declaration of the South Asian Federation of Endocrine Societies

    No full text
    Global warming and endocrine disorders are intertwined issues posing significant challenges. Greenhouse gases emanating from human activities drive global warming, leading to temperature rise and altered weather patterns. South Asia has experienced a noticeable temperature surge over the past century. The sizable population residing in the region heightens the susceptibility to the impact of global warming. In addition to affecting agriculture, water resources, and livelihood, environmental changes interfere with endocrine functioning. Resulting lifestyle changes increase the risk of metabolic and endocrine disorders. Individuals with diabetes face heightened vulnerability to extreme weather due to impaired thermoregulation. A high ambient temperature predisposes to heat-related illnesses, infertility, and nephropathy. Additionally, essential endocrine drugs and medical devices are susceptible to temperature fluctuations. The South Asian Federation of Endocrine Societies (SAFES) calls for collaboration among stakeholders to combat climate change and promote healthy living. Comprehensive approaches, including the establishment of sustainable food systems, promotion of physical activity, and raising awareness about environmental impacts, are imperative. SAFES recommends strategies such as prioritizing plant-based diets, reducing meat consumption, optimizing medical device usage, and enhancing accessibility to endocrine care. Raising awareness and educating caregivers and people living with diabetes on necessary precautions during extreme weather conditions are paramount. The heat sensitivity of insulin, blood glucose monitoring devices, and insulin pumps necessitates proper storage and consideration of environmental conditions for optimal efficacy. The inter-connectedness of global warming and endocrine disorders underscores the necessity of international collaboration guided by national endocrine societies. SAFES urges all stakeholders to actively implement sustainable practices to improve endocrine health in the face of climate change

    The sustainable intensification of agroforestry in shifting cultivation areas of Bangladesh

    No full text
    Shifting cultivation is now considered a largely unsustainable type of agroecosystem because of declines in productivity that come with increasing population pressure, shortening of fallow periods and non-availability of alternative land. Efforts to promote the adoption of agroforestry to improve shifting cultivation systems have been increasing. Here, we discuss intensification of agroforestry in shifting cultivation areas of Bangladesh through community participation. Drawing on field data from a collaborative agroforestry research project implemented in Chittagong hill tracts (CHT), it describes the use of agroforestry development, its sustainability, the challenges and opportunities of agroforestry development. We worked with villagers in three para (hamlets) to develop a participatory approach to the development of agroforestry options. On the basis of a combination of participants’ preferences and expert opinion, crop combinations were selected and agri-horti-silvicultural agroforestry systems developed. These participants now cultivate agricultural crops continuously year-on-year on slopes formerly subject to shifting systems. The benefit-cost ratio for agricultural crops was 3:1. Seedlings are growing well and average survival rates at more than 70 %. More than 80 % participants are now interested in agroforestry, and 54 % desire to expand agroforestry to other areas. For the future development and promotion of agroforestry by tribal communities in the CHT, conclusions are drawn about modes of collaborative working with local partners

    Recent advances in high-temperature fractionation of polyolefins

    No full text
    The synthesis and characterization of polyolefins continues to be one of the most important areas for academic and industrial research. One consequence of the development of new “tailor-made” polyolefins is the need for new and improved analytical techniques for the analysis of polyolefins with respect to molar mass, molecular topology and chemical composition distribution. This review presents different new and relevant techniques for polyolefin analysis. The analysis of copolymers by combining high-temperature SEC and FTIR spectroscopy yields information on chemical composition and molecular topology as a function of molar mass. Crystallization based fractionation techniques are powerful methods for the analysis of short-chain branching in LLDPE and the analysis of polyolefin blends. These methods include temperature-rising elution fractionation, crystallization analysis fractionation and the recently developed crystallization-elution fractionation. The latest development in the field of polyolefin fractionation is high-temperature interaction chromatography. Based on the principles of gradient HPLC and liquid chromatography at critical conditions this method is used for fast analysis of the chemical composition distribution of complex olefin copolymers. The efficiency of HPLC based systems for the separation of various olefin copolymers will be discussed. The ultimate development in high-temperature fractionation of polyolefins is comprehensive high-temperature two-dimensional liquid chromatography. The review will discuss some of the pioneering work that has been done since 2008. Finally, the correlation between molar mass and chemical composition can be accessed by on-line coupling of high-temperature SEC and 1H-NMR spectroscopy. It is shown that the on-line NMR analysis of chromatographic fractions from high-temperature fractionations is possible and yields information on microstructure and tacticity in addition to molar mass and copolymer composition
    corecore