483 research outputs found

    Jekyll & Hyde: Evolution of a Superfamily

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    SummaryAminoacyl-tRNA synthetase mutations have been linked to neurological diseases, but aminoacylation may be unaffected. This protein superfamily also performs many other diverse functions. Yang et al. insightfully engineer a single mutation to unmask a cell signaling activity of tyrosyl-tRNA synthetase [1]

    Diverse cell stresses induce unique patterns of tRNA up- and down-regulation: tRNA-seq for quantifying changes in tRNA copy number

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    Emerging evidence points to roles for tRNA modifications and tRNA abundance in cellular stress responses. While isolated instances of stress-induced tRNA degradation have been reported, we sought to assess the effects of stress on tRNA levels at a systems level. To this end, we developed a next-generation sequencing method that exploits the paucity of ribonucleoside modifications at the 3′-end of tRNAs to quantify changes in all cellular tRNA molecules. Application of this tRNA-seq method to Saccharomyces cerevisiae identified all 76 expressed unique tRNA species out of 295 coded in the yeast genome, including all isoacceptor variants, with highly precise relative (fold-change) quantification of tRNAs. In studies of stress-induced changes in tRNA levels, we found that oxidation (H[subscript 2]O[subscript 2]) and alkylation (methylmethane sulfonate, MMS) stresses induced nearly identical patterns of up- and down-regulation for 58 tRNAs. However, 18 tRNAs showed opposing changes for the stresses, which parallels our observation of signature reprogramming of tRNA modifications caused by H[subscript 2]O[subscript 2] and MMS. Further, stress-induced degradation was limited to only a small proportion of a few tRNA species. With tRNA-seq applicable to any organism, these results suggest that translational control of stress response involves a contribution from tRNA abundance.National Institutes of Health (U.S.) (ES017010)National Institutes of Health (U.S.) (ES002109)National Science Foundation (U.S.) (CHE-1308839)Singapore-MIT Alliance for Research and Technolog

    Interventions for preventing delirium in older people in institutional long-term care

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    BACKGROUND: Delirium is a common and distressing mental disorder. It is often caused by a combination of stressor events in susceptible people, particularly older people living with frailty and dementia. Adults living in institutional long-term care (LTC) are at particularly high risk of delirium. An episode of delirium increases risks of admission to hospital, development or worsening of dementia and death. Multicomponent interventions can reduce the incidence of delirium by a third in the hospital setting. However, it is currently unclear whether interventions to prevent delirium in LTC are effective. This is an update of a Cochrane Review first published in 2014. OBJECTIVES: To assess the effectiveness of interventions for preventing delirium in older people in institutional long-term care settings. SEARCH METHODS: We searched ALOIS (www.medicine.ox.ac.uk/alois), the Cochrane Dementia and Cognitive Improvement Group (CDCIG) 's Specialised Register of dementia trials (dementia.cochrane.org/our-trials-register), to 27 February 2019. The search was sufficiently sensitive to identify all studies relating to delirium. We ran additional separate searches in the Cochrane Central Register of Controlled Trials (CENTRAL), major healthcare databases, trial registers and grey literature sources to ensure that the search was comprehensive. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and cluster-randomised controlled trials (cluster-RCTs) of single and multicomponent, non-pharmacological and pharmacological interventions for preventing delirium in older people (aged 65 years and over) in permanent LTC residence. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Primary outcomes were prevalence, incidence and severity of delirium; and mortality. Secondary outcomes included falls, hospital admissions and other adverse events; cognitive function; new diagnoses of dementia; activities of daily living; quality of life; and cost-related outcomes. We used risk ratios (RRs) as measures of treatment effect for dichotomous outcomes, hazard ratios (HR) for time-to-event outcomes and mean difference (MD) for continuous outcomes. For each outcome, we assessed the overall certainty of the evidence using GRADE methods. MAIN RESULTS: We included three trials with 3851 participants. All three were cluster-RCTs. Two of the trials were of complex, single-component, non-pharmacological interventions and one trial was a feasibility trial of a complex, multicomponent, non-pharmacological intervention. Risk of bias ratings were mixed across the three trials. Due to the heterogeneous nature of the interventions, we did not combine the results statistically, but produced a narrative summary.It was not possible to determine the effect of a hydration-based intervention on delirium incidence (RR 0.85, 95% confidence interval (CI) 0.18 to 4.00; 1 study, 98 participants; very low-certainty evidence downgraded for risk of bias and very serious imprecision). This study did not assess delirium prevalence, severity or mortality.The introduction of a computerised system to identify medications that may contribute to delirium risk and trigger a medication review was probably associated with a reduction in delirium incidence (12-month HR 0.42, CI 0.34 to 0.51; 1 study, 7311 participant-months; moderate-certainty evidence downgraded for risk of bias) but probably had little or no effect on mortality (HR 0.88, CI 0.66 to 1.17; 1 study, 9412 participant-months; moderate-certainty evidence downgraded for imprecision), hospital admissions (HR 0.89, CI 0.72 to 1.10; 1 study, 7599 participant-months; moderate-certainty evidence downgraded for imprecision) or falls (HR 1.03, CI 0.92 to 1.15; 1 study, 2275 participant-months; low-certainty evidence downgraded for imprecision and risk of bias). Delirium prevalence and severity were not assessed.In the enhanced educational intervention study, aimed at changing practice to address key delirium risk factors, it was not possible to determine the effect of the intervention on delirium incidence (RR 0.62, 95% CI 0.16 to 2.39; 1 study, 137 resident months; very low-certainty evidence downgraded for risk of bias and serious imprecision) or delirium prevalence (RR 0.57, 95% CI 0.15 to 2.19; 1 study, 160 participants; very low-certainty evidence downgraded for risk of bias and serious imprecision). There was probably little or no effect on mortality (RR 0.82, CI 0.50 to 1.34; 1 study, 215 participants; moderate-certainty evidence downgraded for imprecision). The intervention was probably associated with a reduction in hospital admissions (RR 0.67, CI 0.57 to 0.79; 1 study, 494 participants; moderate-certainty evidence downgraded due to indirectness). AUTHORS' CONCLUSIONS: Our review identified limited evidence on interventions for preventing delirium in older people in LTC. A software-based intervention to identify medications that could contribute to delirium risk and trigger a pharmacist-led medication review, probably reduces incidence of delirium in older people in institutional LTC. This is based on one large RCT in the US and may not be practical in other countries or settings which do not have comparable information technology services available in care homes. In the educational intervention aimed at identifying risk factors for delirium and developing bespoke solutions within care homes, it was not possible to determine the effect of the intervention on delirium incidence, prevalence or mortality. This evidence is based on a small feasibility trial. Our review identified three ongoing trials of multicomponent delirium prevention interventions. We identified no trials of pharmacological agents. Future trials of multicomponent non-pharmacological delirium prevention interventions for older people in LTC are needed to help inform the provision of evidence-based care for this vulnerable group

    N-butanol Extract from Melilotus Suaveolens Ledeb Affects Pro- and Anti-Inflammatory Cytokines and Mediators

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    Melilotus suaveolens Ledeb is a traditional medicinal plant for treating inflammation-related disease. This explores the inner anti-inflammatory mechanism of n-butanol extract from M. suaveolens Ledeb. Inflammatory cellular model was established by lipopolysaccharide intervention on RAW264.7 cell line. Levels of secreted cytokines TNF-α, IL-1β, IL-6, NO and IL-10 in supernatant, mRNA expression of TNF-α, COX-2, iNOS and HO-1, protein expression of COX-2 and HO-1, activation of NF-κB and ingredients in the extract were assayed by ELISA, real time quantitative PCR, western blot, immunocytochemical test and HPLC fingerprint test, respectively. As a result, the extract could not only markedly reduce the production of pro-inflammatory mediators to different extents by blocking NF-κB activation but also promote the release of anti-inflammatory mediator HO-1 significantly. Each 1 g extract contained 0.023531 mg coumarin and another two high polar ingredients, probably saponins. It can be concluded that the extract has similar effects on antagonizing pro-inflammatory mediators and cytokines like Dexamethasone, and has effects on promoting the production of anti-inflammatory mediators

    Mycobacterial RNA isolation optimized for non-coding RNA: high fidelity isolation of 5S rRNA from Mycobacterium bovis BCG reveals novel post-transcriptional processing and a complete spectrum of modified ribonucleosides

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    A major challenge in the study of mycobacterial RNA biology is the lack of a comprehensive RNA isolation method that overcomes the unusual cell wall to faithfully yield the full spectrum of non-coding RNA (ncRNA) species. Here, we describe a simple and robust procedure optimized for the isolation of total ncRNA, including 5S, 16S and 23S ribosomal RNA (rRNA) and tRNA, from mycobacteria, using Mycobacterium bovis BCG to illustrate the method. Based on a combination of mechanical disruption and liquid and solid-phase technologies, the method produces all major species of ncRNA in high yield and with high integrity, enabling direct chemical and sequence analysis of the ncRNA species. The reproducibility of the method with BCG was evident in bioanalyzer electrophoretic analysis of isolated RNA, which revealed quantitatively significant differences in the ncRNA profiles of exponentially growing and non-replicating hypoxic bacilli. The method also overcame an historical inconsistency in 5S rRNA isolation, with direct sequencing revealing a novel post-transcriptional processing of 5S rRNA to its functional form and with chemical analysis revealing seven post-transcriptional ribonucleoside modifications in the 5S rRNA. This optimized RNA isolation procedure thus provides a means to more rigorously explore the biology of ncRNA species in mycobacteria.Singapore-MIT Alliance for Research and TechnologyNational Institute of Environmental Health Sciences (ES017010)National Institute of Environmental Health Sciences (ES002109)Singapore-MIT Alliance (Graduate Fellowship)Singapore. National Research Foundatio

    Anti-inflammatory and anti-oxidative effects of corilagin in a rat model of acute cholestasis

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    BACKGROUND: Nowadays, treatments for cholestasis remain largely nonspecific and often ineffective. Recent studies showed that inflammatory injuries and oxidative stress occur in the liver with cholestasis. In this study, we would use corilagin to treat the animal model of acute cholestasis in order to define the activity to interfere with inflammation-related and oxidative stress pathway in cholestatic pathogenesis. METHODS: Rats were administrated with alpha-naphthylisothiocyanate to establish model of cholestasis and divided into corilagin, ursodeoxycholic acid, dexamethasone, model and normal groups with treatment of related agent. At 24h, 48h and 72h time points after administration, living condition, serum markers of liver damage, pathological changes of hepatic tissue, nuclear factor (NF)-kappaB, myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide (NO) were examined and observed. RESULTS: Compared to model group, corilagin had remarkable effect on living condition, pathological manifestation of liver tissue, total bilirubin, direct bilirubin, (P<0.01), but no effect on alanine aminotransferase (ALT) and aspartate aminotransferase (AST). With corilagin intervention, levels of MPO, MDA and translocation of NF-κB were notably decreased, and levels of SOD and NO were markedly increased (P<0.05 or P<0.01). CONCLUSIONS: It is shown that corilagin is a potential component to relieve cholestasis through inflammation-related and oxidation-related pathway

    Functional Characterization of Olfactory Proteins Involved in Chemoreception of Galeruca daurica

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    Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) play a fundamental role in insect olfaction. Galeruca daurica (Joannis) is a new pest with outbreak status in the Inner Mongolia grasslands, northern China. In this study, six olfactory protein genes (GdauOBP1, GdauOBP6, GdauOBP10, GdauOBP15, GdauCSP4, and GdauCSP5) were cloned by RACE and expressed by constructing a prokaryotic expression system. Their binding affinities to 13 compounds from host volatiles (Allium mongolicum) were determined by fluorescence-binding assay. In order to further explore the olfactory functions of GdauOBP15 and GdauCSP5, RNA interference (RNAi) and electroantennogram (EAG) experiments were conducted. Ligand-binding assays showed that the binding properties of the six recombinant proteins to the tested volatiles were different. GdauOBP6, GdauOBP15, GdauCSP4, and GdauCSP5 could bind several tested ligands of host plants. It was suspected that GdauOBP6, GdauOBP15, GdauCSP4, and GdauCSP5 were related to the host location in G. daurica. We also found that there were different EAG responses between males and females when the GdauOBP15 and GdauCSP5 genes were silenced by RNAi. The EAG response of G. daurica females to 2-hexenal was significantly decreased in dsRNA-OBP15-injected treatment compared to the control, and the dsRNA-CSP5-treated females significantly reduced EAG response to eight tested host volatiles (1,3-dithiane, 2-hexenal, methyl benzoate, dimethyl trisulfide, myrcene, hexanal, 1,3,5-cycloheptatriene, and p-xylene). However, the EAG response had no significant difference in males. Both GdauOBP15 and GdauCSP5 may have different functions between males and females in G. daurica and may play more important roles in females searching for host plants

    Case Report Low-grade endometrioid carcinoma of the ovary associated with undifferentiated carcinoma: case report and review of the literature

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    Abstract: The association of low-grade endometrioid carcinoma with undifferentiated carcinoma (UC) was first reported in endometrium carcinoma, termed with dedifferentiated carcinoma (DC). However, the coexistence of lowgrade endometrioid carcinoma (LGEC) or serous carcinoma (LGSC) with UC has received minimal attention in ovary, and the behavior of this kind of neoplasm remains at further discussion. In this study, we reported a case of lowgrade ovarian endometrioid carcinoma associated with UC and reviewed another four cases previously reported. We found a histological continuity between the LGEC and UC components in H&amp;E section, which suggested a dedifferentiation from LGEC to UC components. In summary, this kind of pathological type has aggressive behavior and these patients have very poor prognosis regardless of the amount of undifferentiated carcinoma
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