38 research outputs found

    Expression of the NH2-Terminal Fragment of RasGAP in Pancreatic β-Cells Increases Their Resistance to Stresses and Protects Mice From Diabetes

    Get PDF
    OBJECTIVE: Our laboratory has previously established in vitro that a caspase-generated RasGAP NH(2)-terminal moiety, called fragment N, potently protects cells, including insulinomas, from apoptotic stress. We aimed to determine whether fragment N can increase the resistance of pancreatic beta-cells in a physiological setting. RESEARCH DESIGN AND METHODS: A mouse line, called rat insulin promoter (RIP)-N, was generated that bears a transgene containing the rat insulin promoter followed by the cDNA-encoding fragment N. The histology, functionality, and resistance to stress of RIP-N islets were then assessed. RESULTS: Pancreatic beta-cells of RIP-N mice express fragment N, activate Akt, and block nuclear factor kappaB activity without affecting islet cell proliferation or the morphology and cellular composition of islets. Intraperitoneal glucose tolerance tests revealed that RIP-N mice control their glycemia similarly as wild-type mice throughout their lifespan. Moreover, islets isolated from RIP-N mice showed normal glucose-induced insulin secretory capacities. They, however, displayed increased resistance to apoptosis induced by a series of stresses including inflammatory cytokines, fatty acids, and hyperglycemia. RIP-N mice were also protected from multiple low-dose streptozotocin-induced diabetes, and this was associated with reduced in vivo beta-cell apoptosis. CONCLUSIONS: Fragment N efficiently increases the overall resistance of beta-cells to noxious stimuli without interfering with the physiological functions of the cells. Fragment N and the pathway it regulates represent, therefore, a potential target for the development of antidiabetes tools

    ENERGY AND EXERGY ANALYSIS OF A VAPOR ABSORPTION REFRIGERATION SYSTEM IN AN INTERCITY BUS APPLICATION

    No full text
    WOS: 000476619800010A Vapor Absorption Refrigeration (VAR) system driven by the exhaust gas waste heat received from the internal combustion engine of an intercity bus is modeled and analyzed for air-conditioning the intercity bus cabin under different operating parameters. Initially, the hourly comfort cooling load of the intercity bus is calculated for a cooling season spanning five months between May and October in Turkey. After determining the capacity of heat source sufficiency for air-conditioning the intercity bus, energy and exergy analyses of the VAR system are conducted, then designed and compared with the vapor compression refrigeration system in respect to the effect of fuel consumption. The results show that approximately 4,489 kg/year of fuel can be saved by using the VAR system driven by an exhaust gas waste heat in an intercity bus. The maximum coefficient of performance (COP) of the VAR system is obtained as 0.78 at 5 a.m. in May, and the maximum total exergy destruction for the VAR system is obtained as 15.25 kW at 4 p.m. in July. Lastly, the specific time is selected to investigate the effect of operating and environmental parameters on the VAR system

    Natural language processing for structuring clinical text data on depression using UK-CRIS

    No full text
    Background Utilisation of routinely collected electronic health records from secondary care offers unprecedented possibilities for medical science research but can also present difficulties. One key issue is that medical information is presented as free-form text and, therefore, requires time commitment from clinicians to manually extract salient information. Natural language processing (NLP) methods can be used to automatically extract clinically relevant information. Objective Our aim is to use natural language processing (NLP) to capture real-world data on individuals with depression from the Clinical Record Interactive Search (CRIS) clinical text to foster the use of electronic healthcare data in mental health research. Methods We used a combination of methods to extract salient information from electronic health records. First, clinical experts define the information of interest and subsequently build the training and testing corpora for statistical models. Second, we built and fine-tuned the statistical models using active learning procedures. Findings Results show a high degree of accuracy in the extraction of drug-related information. Contrastingly, a much lower degree of accuracy is demonstrated in relation to auxiliary variables. In combination with state-of-the-art active learning paradigms, the performance of the model increases considerably. Conclusions This study illustrates the feasibility of using the natural language processing models and proposes a research pipeline to be used for accurately extracting information from electronic health records. Clinical implications Real-world, individual patient data are an invaluable source of information, which can be used to better personalise treatment.</p

    Primary cilia are critical for Sonic hedgehog-mediated dopaminergic neurogenesis in the embryonic midbrain

    Get PDF
    AbstractMidbrain dopaminergic (mDA) neurons modulate various motor and cognitive functions, and their dysfunction or degeneration has been implicated in several psychiatric diseases. Both Sonic Hedgehog (Shh) and Wnt signaling pathways have been shown to be essential for normal development of mDA neurons. Primary cilia are critical for the development of a number of structures in the brain by serving as a hub for essential developmental signaling cascades, but their role in the generation of mDA neurons has not been examined. We analyzed mutant mouse lines deficient in the intraflagellar transport protein IFT88, which is critical for primary cilia function. Conditional inactivation of Ift88 in the midbrain after E9.0 results in progressive loss of primary cilia, a decreased size of the mDA progenitor domain, and a reduction in mDA neurons. We identified Shh signaling as the primary cause of these defects, since conditional inactivation of the Shh signaling pathway after E9.0, through genetic ablation of Gli2 and Gli3 in the midbrain, results in a phenotype basically identical to the one seen in Ift88 conditional mutants. Moreover, the expansion of the mDA progenitor domain observed when Shh signaling is constitutively activated does not occur in absence of Ift88. In contrast, clusters of Shh-responding progenitors are maintained in the ventral midbrain of the hypomorphic Ift88 mouse mutant, cobblestone. Despite the residual Shh signaling, the integrity of the mDA progenitor domain is severely disturbed, and consequently very few mDA neurons are generated in cobblestone mutants. Our results identify for the first time a crucial role of primary cilia in the induction of mDA progenitors, define a narrow time window in which Shh-mediated signaling is dependent upon normal primary cilia function for this purpose, and suggest that later Wnt signaling-dependent events act independently of primary cilia

    Targeted fetal cell-free DNA screening for aneuploidies in 4,594 pregnancies: Single center study

    No full text
    Background Next-generation sequencing (NGS) and discovery of fetal cell-free DNA (cfDNA) in the maternal circulation render possible prenatal screening for trisomy 21 (Down syndrome), trisomy 18, trisomy 13, and sex chromosome aneuploidies. The approach is called "fetal cfDNA screening" and in contrast to noninvasive conventional serum screening, it provides the identification of 98%-99% of fetuses with Down syndrome. Methods Retrospective analysis of targeted noninvasive prenatal testing (NIPT) (Clarigo Test) pregnancies with moderate risk, which we have reported between 2016 and 2018 years is presented. Two separate laboratory workflows and NGS platforms are used for the same targeted NIPT analysis. Results In total, 4,594 pregnant women were investigated. Initial 3,594 cases are studied by MiSeq platform, the last 1,000 cases by NextSeq. Failure rate for MiSeq platform is 10.9% and for NextSeq is 8.7%. Automatically reported cases constitute 75% of the MiSeq group and 87% of the NextSeq group. Conclusions Targeted NIPT results suggest that MiSeq platform could be used for NIPT which would be an essential option particularly for laboratories with low sample flow. And, the NextSeq platform has easier wet lab process and also increased success rate in automatic reporting which is suitable for centers with high number of NIPT cases
    corecore