93 research outputs found

    Repercussion of Mitochondria Deformity Induced by Anti-Hsp90 Drug 17AAG in Human Tumor Cells

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    Inhibiting Hsp90 chaperone roles using 17AAG induces cytostasis or apoptosis in tumor cells through destabilization of several mutated cancer promoting proteins. Although mitochondria are central in deciding the fate of cells, 17AAG induced effects on tumor cell mitochondria were largely unknown. Here, we show that Hsp90 inhibition with 17AAG first affects mitochondrial integrity in different human tumor cells, neuroblastoma, cervical cancer and glial cells. Using human neuroblastoma tumor cells, we found the early effects associated with a change in mitochondrial membrane potential, elongation and engorgement of mitochondria because of an increased matrix vacuolization. These effects are specific to Hsp90 inhibition as other chemotherapeutic drugs did not induce similar mitochondrial deformity. Further, the effects are independent of oxidative damage and cytoarchitecture destabilization since cytoskeletal disruptors and mitochondrial metabolic inhibitors also do not induce similar deformity induced by 17AAG. The 1D PAGE LC MS/MS mitochondrial proteome analysis of 17AAG treated human neuroblastoma cells showed a loss of 61% proteins from membrane, metabolic, chaperone and ribonucleoprotein families. About 31 unmapped protein IDs were identified from proteolytic processing map using Swiss-Prot accession number, and converted to the matching gene name searching the ExPASy proteomics server. Our studies display that Hsp90 inhibition effects at first embark on mitochondria of tumor cells and compromise mitochondrial integrity

    Phosphorylation-Independent Regulation of the Diguanylate Cyclase WspR

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    Environmental signals that trigger bacterial pathogenesis and biofilm formation are mediated by changes in the level of cyclic dimeric guanosine monophosphate (c-di-GMP), a unique eubacterial second messenger. Tight regulation of cellular c-di-GMP concentration is governed by diguanylate cyclases and phosphodiesterases, which are responsible for its production and degradation, respectively. Here, we present the crystal structure of the diguanylate cyclase WspR, a conserved GGDEF domain-containing response regulator in Gram-negative bacteria, bound to c-di-GMP at an inhibitory site. Biochemical analyses revealed that feedback regulation involves the formation of at least three distinct oligomeric states. By switching from an active to a product-inhibited dimer via a tetrameric assembly, WspR utilizes a novel mechanism for modulation of its activity through oligomerization. Moreover, our data suggest that these enzymes can be activated by phosphodiesterases. Thus, in addition to the canonical pathways via phosphorylation of the regulatory domains, both product and enzyme concentration contribute to the coordination of c-di-GMP signaling. A structural comparison reveals resemblance of the oligomeric states to assemblies of GAF domains, widely used regulatory domains in signaling molecules conserved from archaea to mammals, suggesting a similar mechanism of regulation

    Uma revisão sobre polimerização de olefinas usando catalisadores Ziegler-Natta heterogêneos

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    Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

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    BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed

    Duodenal diverticulum and associated pancreatitis: case report with brief review of literature

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    Pancreatitis in the elderly is a problem of increasing occurrence and is associated with severe complications. Periampullary diverticula (PAD) are extraluminal outpouchings of the duodenum rarely associated with pancreatitis. The presence of PAD should be excluded before diagnosing idiopathic pancreatitis, particularly in the elderly. However, when a duodenal diverticulum is found in the absence of any additional pathology, only then should the symptoms be attributed to the diverticulum. We describe a case of duodenal diverticulum presenting with pancreatitis to emphasize the importance of this commonly neglected etiology

    Effect of resolution on player performance and experience in virtual reality low-fidelity first-person shooting games

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    Background. With the increasing popularity of virtual reality(VR) in gaming              applications, it is important to understand the factors that influence the user experienceof players in VR games. One such factor is the resolution of the VR headsets, whichdetermines the clarity and sharpness of the applications on the screen. However,achieving higher visual details can consume a lot of computational power and limitaccessibility for users with lower-end hardware. Objectives. The aim of this project was to determine if different resolution settingsavailable in VR affect the performance of players, their game experience, and simulator sickness symptoms. The objectives of the thesis project included the developmentof an FPS game prototype with low visual details, designing and conducting a userstudy, and analyzing the data collected during the experiment to find any relationbetween different resolutions on the performance and experience of the participants. Methods. A VR FPS game prototype was developed with a low level of visualdetails which was played in varying resolutions from 2k to 4k. Participants (n=27)were asked to play the game in each resolution and complete surveys on game experience and simulator sickness using standard questionnaires. The performance of theparticipants was measured by recording the time taken to hit targets, and the totalpoints scored at the end of 90 seconds in each resolution. Results. The results indicated that there was no significant difference in player performance and experience of participants in 2k, 3k, and 4k resolutions. The simulatorsickness symptoms such as eyestrain and difficulty in focusing and concentrating werefound to be most extreme in the highest and lowest resolution. Conclusions. In conclusion, this thesis project found that increasing resolution doesnot necessarily increase the performance and experience of players in the VR FPSgame prototype. However, the simulator sickness symptoms depend on the resolutionand are of statistical importance in the highest(4k) and the lowest(2k) resolution

    Final report on extension of AIT - IDRC jab seeder in Thailand

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    Published in association with Thailand Dept. of Agricultural Extension, Ministry of Agriculture and Cooperative

    Effect of resolution on player performance and experience in virtual reality low-fidelity first-person shooting games

    No full text
    Background. With the increasing popularity of virtual reality(VR) in gaming              applications, it is important to understand the factors that influence the user experienceof players in VR games. One such factor is the resolution of the VR headsets, whichdetermines the clarity and sharpness of the applications on the screen. However,achieving higher visual details can consume a lot of computational power and limitaccessibility for users with lower-end hardware. Objectives. The aim of this project was to determine if different resolution settingsavailable in VR affect the performance of players, their game experience, and simulator sickness symptoms. The objectives of the thesis project included the developmentof an FPS game prototype with low visual details, designing and conducting a userstudy, and analyzing the data collected during the experiment to find any relationbetween different resolutions on the performance and experience of the participants. Methods. A VR FPS game prototype was developed with a low level of visualdetails which was played in varying resolutions from 2k to 4k. Participants (n=27)were asked to play the game in each resolution and complete surveys on game experience and simulator sickness using standard questionnaires. The performance of theparticipants was measured by recording the time taken to hit targets, and the totalpoints scored at the end of 90 seconds in each resolution. Results. The results indicated that there was no significant difference in player performance and experience of participants in 2k, 3k, and 4k resolutions. The simulatorsickness symptoms such as eyestrain and difficulty in focusing and concentrating werefound to be most extreme in the highest and lowest resolution. Conclusions. In conclusion, this thesis project found that increasing resolution doesnot necessarily increase the performance and experience of players in the VR FPSgame prototype. However, the simulator sickness symptoms depend on the resolutionand are of statistical importance in the highest(4k) and the lowest(2k) resolution
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