1,202 research outputs found
The Effect of ICT Self-Discipline in the Workplace
The ubiquity of Information and Communication Technologies (ICTs) in work settings has changed the way employees behave. ICTs such as smartphones, email and social media makes employees more connected than has ever been possible. The degree of ICT connectivity can create a positive as well as a negative impact on employees’ productivity. In this context, the notion of ICT self-discipline – an individual’s ability to regulate their behaviours towards ICTs – becomes pivotal in the process of managing ICT connectivity. This follow-on study reports the results of an online survey of 443 to New Zealand professionals regarding the influence of ICT self-discipline on the relationship between ICT connectivity and employee productivity. Findings indicated that the impact of ICT self-discipline varies depending on the organisation and industry an employee works in. Insights and recommendations for future research are shared in this paper. Findings from this study contribute to IS research and practice
The mechanism of formation of 8,8-dimethyl[4.2.1.0 3,7]nonan-6-yl acetate (fortesyl acetate) during acetolysis of nopyl toluene-psulfonate
Attempts to prepare 2-(2-hydroxyethyl)-6,6-dimethylbicyclo[3.1.1]hept-2-ene (nopol; 1) labelled with deuterium at
C-10 by a process of oxidation of the primary alcohol group of nopol to the aldehyde, followed by H/D exchange
and reduction back to alcohol, were unsuccessful because various oxidation procedures, including reaction with
N-chlorosuccinimide at 278 8C, gave instead a carboxylic acid having an oxygen at C-3. Nopol, labelled at C-11
with deuterium, was obtained through a Prins reaction of b-pinene with deuteriated paraformaldehyde. This
labelled nopol was converted into its toluene-p-sulfonate ester, and was solvolysed in acetic acid containing acetate
ion to give 8,8-dimethyltricyclo[4.2.1.03,7]nonan-6-yl acetate, which is an earlier reported novel fused ring system
(fortesyl acetate; 2 acetate). The position of the label in the product showed that the mechanism of this deep-seated
carbon skeletal rearrangement proceeds through the intermediate formation of a cyclobutane ring, followed by
shift of a methylene bridge to expand the original cyclobutane ring and then subsequent expansion of the new
cyclobutane ring. Calculations of heats of formation of possible ions involved in these shifts confirm the proposed
mechanism as the most likely pathway.Junta Nacional de Investigação CientÃfica e Tecnológica.
Kuwait.
Eschenmoser Trust UK
Vitamin D attenuates sphingosine-1-phosphate (S1P)-mediated inhibition of extravillous trophoblast migration.
Failure of trophoblast invasion and remodelling of maternal blood vessels leads to the pregnancy complication pre-eclampsia (PE). In other systems, the sphingolipid, sphingosine-1-phosphate (S1P), controls cell migration therefore this study determined its effect on extravillous trophoblast (EVT) function.A transwell migration system was used to assess the behaviour of three trophoblast cell lines, Swan-71, SGHPL-4, and JEG3, and primary human trophoblasts in the presence or absence of S1P, S1P pathway inhibitors and 1,25(OH)2D3. QPCR and immunolocalisation were used to demonstrate EVT S1P receptor expression.EVTs express S1P receptors 1, 2 and 3. S1P inhibited EVT migration. This effect was abolished in the presence of the specific S1PR2 inhibitor, JTE-013 (p < 0.05 versus S1P alone) whereas treatment with the S1R1/3 inhibitor, FTY720, had no effect. In other cell types S1PR2 is regulated by vitamin D; here we found that treatment with 1,25(OH)2D3 for 48 or 72 h reduces S1PR2 (4-fold; <0.05), but not R1 and R3, expression. Moreover, S1P did not inhibit the migration of cells exposed to 1,25(OH)2D3 (p < 0.05).This study demonstrates that although EVT express three S1P receptor isoforms, S1P predominantly signals through S1PR2/Gα12/13 to activate Rho and thereby acts as potent inhibitor of EVT migration. Importantly, expression of S1PR2, and therefore S1P function, can be down-regulated by vitamin D. Our data suggest that vitamin D deficiency, which is known to be associated with PE, may contribute to the impaired trophoblast migration that underlies this condition
A new role under sortilin's belt in cancer.
The neurotensin receptor-3 also known as sortilin was the first member of the small family of vacuolar protein sorting 10 protein domain (Vps10p) discovered two decades ago in the human brain. The expression of sortilin is not confined to the nervous system but sortilin is ubiquitously expressed in many tissues. Sortilin has multiple roles in the cell as a receptor or a co-receptor, in protein transport of many interacting partners to the plasma membrane, to the endocytic pathway and to the lysosomes for protein degradation. Sortilin could be considered as the cells own shuttle system. In many human diseases including neurological diseases and cancer, sortilin expression has been shown to be deregulated. In addition, some studies have highlighted that the extracellular domain of sortilin is shedded into the culture media by an unknown mechanism. Sortilin can be released in exosomes and appears to control some mechanisms of exosome biogenesis. In lung cancer cells, sortilin can associate with two receptor tyrosine kinase receptors called the TES complex found in exosomes. Exosomes carrying the TES complex can convey a microenvironment control through the activation of ErbB signaling pathways and the release of angiogenic factors. Deregulation of sortilin function is now emerging to be implicated in four major human diseases- cardiovascular disease, Type 2 diabetes mellitus, Alzheimer’s disease and cancer
Investigating the Links between Lower Iron Status in Pregnancy and Respiratory Disease in Offspring Using Murine Models.
Maternal iron deficiency occurs in 40-50% of all pregnancies and is associated with an increased risk of respiratory disease and asthma in children. We used murine models to examine the effects of lower iron status during pregnancy on lung function, inflammation and structure, as well as its contribution to increased severity of asthma in the offspring. A low iron diet during pregnancy impairs lung function, increases airway inflammation, and alters lung structure in the absence and presence of experimental asthma. A low iron diet during pregnancy further increases these major disease features in offspring with experimental asthma. Importantly, a low iron diet increases neutrophilic inflammation, which is indicative of more severe disease, in asthma. Together, our data demonstrate that lower dietary iron and systemic deficiency during pregnancy can lead to physiological, immunological and anatomical changes in the lungs and airways of offspring that predispose to greater susceptibility to respiratory disease. These findings suggest that correcting iron deficiency in pregnancy using iron supplements may play an important role in preventing or reducing the severity of respiratory disease in offspring. They also highlight the utility of experimental models for understanding how iron status in pregnancy affects disease outcomes in offspring and provide a means for testing the efficacy of different iron supplements for preventing disease
The transcriptional response of Caenorhabditis elegans to ivermectin exposure identifies novel genes involved in the response to reduced food intake
We have examined the transcriptional response of Caenorhabditis elegans following exposure to the anthelmintic drug ivermectin (IVM) using whole genome microarrays and real-time QPCR. Our original aim was to identify candidate molecules involved in IVM metabolism and/or excretion. For this reason the IVM tolerant strain, DA1316, was used to minimise transcriptomic changes related to the phenotype of drug exposure. However, unlike equivalent work with benzimidazole drugs, very few of the induced genes were members of xenobiotic metabolising enzyme families. Instead, the transcriptional response was dominated by genes associated with fat mobilization and fatty acid metabolism including catalase, esterase, and fatty acid CoA synthetase genes. This is consistent with the reduction in pharyngeal pumping, and consequential reduction in food intake, upon exposure of DA1316 worms to IVM. Genes with the highest fold change in response to IVM exposure, cyp-37B1, mtl-1 and scl-2, were comparably up-regulated in response to short–term food withdrawal (4 hr) independent of IVM exposure, and GFP reporter constructs confirm their expression in tissues associated with fat storage (intestine and hypodermis). These experiments have serendipitously identified novel genes involved in an early response of C. elegans to reduced food intake and may provide insight into similar processes in higher organisms
Association between proton pump inhibitor therapy and clostridium difficile infection: a contemporary systematic review and meta-analysis.
Abstract
Introduction
Emerging epidemiological evidence suggests that proton pump inhibitor (PPI) acid-suppression therapy is associated with an increased risk of Clostridium difficile infection (CDI).
Methods
Ovid MEDLINE, EMBASE, ISI Web of Science, and Scopus were searched from 1990 to January 2012 for analytical studies that reported an adjusted effect estimate of the association between PPI use and CDI. We performed random-effect meta-analyses. We used the GRADE framework to interpret the findings.
Results
We identified 47 eligible citations (37 case-control and 14 cohort studies) with corresponding 51 effect estimates. The pooled OR was 1.65, 95% CI (1.47, 1.85), I2 = 89.9%, with evidence of publication bias suggested by a contour funnel plot. A novel regression based method was used to adjust for publication bias and resulted in an adjusted pooled OR of 1.51 (95% CI, 1.26–1.83). In a speculative analysis that assumes that this association is based on causality, and based on published baseline CDI incidence, the risk of CDI would be very low in the general population taking PPIs with an estimated NNH of 3925 at 1 year.
Conclusions
In this rigorously conducted systemic review and meta-analysis, we found very low quality evidence (GRADE class) for an association between PPI use and CDI that does not support a cause-effect relationship
Benefit of early commencement of growth hormone therapy in children with Prader-Willi syndrome
Prader-Willi syndrome (PWS) is a chromosomal disorder and growth failure is a common presentation. Growth hormone (GH) treatment is beneficial in PWS although the optimal age for starting GH is unknown. We investigated whether GH response in PWS was associated with the age of GH commencement by comparing 16 children who commenced GH before 3 years of age (early group) with 40 children who commenced GH after 3 years of age (late group) from the Ozgrow database. Height SDS, body mass index (BMI) SDS, bone age (BA)-chronological age (CA) ratio, change in height (Delta Ht) SDS and change in BMI during 4 years of GH treatment were compared between the groups. The early group had better height SDS and Delta Ht SIDS. BA delay was more pronounced in the early group but BA did not mature beyond CA with GH therapy in either group. Although the initial GH dose for the early group was lower than that of the late group, the former had better height outcome. The starting GH dose seen in the database is lower than the dose used by international centres
Docetaxel-loaded liposomes: The effect of lipid composition and purification on drug encapsulation and in vitro toxicity
Docetaxel (DTX)-loaded liposomes have been formulated to overcome DTX solubility issue, improve its efficacy and reduce its toxicity. This study investigated the effect of steric stabilisation, varying liposome composition, and lipid:drug molar ratio on drug loading and on the physicochemical properties of the DTX-loaded liposomes. Size exclusion chromatography (SEC) was used to remove free DTX from the liposomal formulation, and its impact on drug loading and in vitro cytotoxicity was also evaluated. Liposomes composed of fluid, unsaturated lipid (DOPC:Chol:DSPE-PEG2000) showed the highest DTX loading compared to rigid, saturated lipids (DPPC:Chol:DSPE-PEG2000 and DSPC:Chol:DSPE-PEG2000). The inclusion of PEG showed a minimum effect on DTX encapsulation. Decreasing lipid:drug molar ratio from 40:1 to 5:1 led to an improvement in the loading capacities of DOPC-based liposomes only. Up to 3.6-fold decrease in drug loading was observed after liposome purification, likely due to the loss of adsorbed and loosely entrapped DTX in the SEC column. Our in vitro toxicity results in PC3 monolayer showed that non-purified, DTX-loaded DOPC:Chol liposomes were initially (24h) more potent than the purified ones, due to the fast action of the surface- adsorbed drug. However, we hypothesize that over time (48 and 72h) the purified, DTX-loaded DOPC:Chol liposomes became more toxic due to high intracellular release of encapsulated DTX. Finally, our cytotoxicity results in PC3 spheroids showed the superior activity of DTX-loaded liposomes compared to free DTX, which could overcome the DTX poor tissue penetration, drug resistance, and improve its therapeutic efficacy following systemic administration
Characterization of RNA in exosomes secreted by human breast cancer cell lines using next-generation sequencing
Exosomes are nanosized (30–100 nm) membrane vesicles secreted by most cell types. Exosomes have been found to contain various RNA species including miRNA, mRNA and long non-protein coding RNAs. A number of cancer cells produce elevated levels of exosomes. Because exosomes have been isolated from most body fluids they may provide a source for non-invasive cancer diagnostics. Transcriptome profiling that uses deep-sequencing technologies (RNA-Seq) offers enormous amount of data that can be used for biomarkers discovery, however, in case of exosomes this approach was applied only for the analysis of small RNAs. In this study, we utilized RNA-Seq technology to analyze RNAs present in microvesicles secreted by human breast cancer cell lines.Exosomes were isolated from the media conditioned by two human breast cancer cell lines, MDA-MB-231 and MDA-MB-436. Exosomal RNA was profiled using the Ion Torrent semiconductor chip-based technology. Exosomes were found to contain various classes of RNA with the major class represented by fragmented ribosomal RNA (rRNA), in particular 28S and 18S rRNA subunits. Analysis of exosomal RNA content revealed that it reflects RNA content of the donor cells. Although exosomes produced by the two cancer cell lines shared most of the RNA species, there was a number of non-coding transcripts unique to MDA-MB-231 and MDA-MB-436 cells. This suggests that RNA analysis might distinguish exosomes produced by low metastatic breast cancer cell line (MDA-MB-436) from that produced by highly metastatic breast cancer cell line (MDA-MB-231). The analysis of gene ontologies (GOs) associated with the most abundant transcripts present in exosomes revealed significant enrichment in genes encoding proteins involved in translation and rRNA and ncRNA processing. These GO terms indicate most expressed genes for both, cellular and exosomal RNA.For the first time, using RNA-seq, we examined the transcriptomes of exosomes secreted by human breast cancer cells. We found that most abundant exosomal RNA species are the fragments of 28S and 18S rRNA subunits. This limits the number of reads from other RNAs. To increase the number of detectable transcripts and improve the accuracy of their expression level the protocols allowing depletion of fragmented rRNA should be utilized in the future RNA-seq analyses on exosomes. Present data revealed that exosomal transcripts are representative of their cells of origin and thus could form basis for detection of tumor specific markers
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