68 research outputs found
Assessing the impact of laws controlling the online availability of 25I-NBOMe, AH-7921, MDPV and MXE – outcomes of a semi-automated e-shop monitoring
Aims: The indicator of availability has been used in the risk assessment (RA) of new psychoactive substances (NPS). This paper aims to examine the pre- and post-control availability of 25INBOMe, AH-7921, MDPV and MXE, which were assessed by the EMCDDA. Methods: Data were collected by a semi-automated software tool (I-TREND SASF) on e-shops in national languages (Czech, French, Dutch, Polish and English) that offered shipping of these compounds into the respective countries; frequency analysis was used. Findings: The number of e-shops selling these substances decreased between III/2014 and XII/2015 (except for AH-7921). Both increases and decreases were found on the country-level for all the compounds (except for an overall decrease for MXE). In one instance an NPS disappeared from this market in 2015 (25I-NBOMe in NL); 25I-NBOMe and AH-7921 in France and AH-7921 in Poland appeared for the first time in 2015 after they were put under control. The e-shops listing AH-7921, 25I-NBOMe and MDPV in XII/2015 ranked higher in terms of ‘‘popularity’’ than in III/2014. The IP addresses were more likely to be outside the EU in 2015 than in 2014. Conclusions: We found no evidence that national-level compound bans contributed to the changes in online NPS markets. Indicators of the accessibility, availability, popularity, and IP origin should be considered in RA. Data triangulation with street markets and the darknet is needed as well as more research into the ‘‘displacement’’ and ‘‘replacement’’ effects of control laws
A business model perspective for ICTs in public engagement
This is the post-print version of the Article. The official published article can be accessed from the link below - Copyright @ 2012 ElsevierPublic institutions, in their efforts to promote meaningful citizen engagement, are increasingly looking at the democratic potential of Information and Communication Technologies (ICTs). Previous studies suggest that such initiatives seem to be impeded by socio-technical integration barriers such as low sustainability, poor citizen acceptance, coordination difficulties, lack of understanding and failure to assess their impact. Motivated by these shortcomings, the paper develops and applies a business model perspective as an interceding framework for analysis and evaluation. The underlying principle behind this approach is that it is not technology per se which determines success, but rather the way in which the businessmodel of the technological artifact is configured and employed to achieve the strategic goals. The business model perspective is empirically demonstrated with the case of an online petitioning system implemented by a UK local authority. The case illustrates the importance of considering ICTs in public engagement from a holistic view to make them more manageable and assessable
Human DNA polymerase ε is a source of C>T mutations at CpG dinucleotides.
C-to-T transitions in CpG dinucleotides are the most prevalent mutations in human cancers and genetic diseases. These mutations have been attributed to deamination of 5-methylcytosine (5mC), an epigenetic modification found on CpGs. We recently linked CpG>TpG mutations to replication and hypothesized that errors introduced by polymerase ε (Pol ε) may represent an alternative source of mutations. Here we present a new method called polymerase error rate sequencing (PER-seq) to measure the error spectrum of DNA polymerases in isolation. We find that the most common human cancer-associated Pol ε mutant (P286R) produces an excess of CpG>TpG errors, phenocopying the mutation spectrum of tumors carrying this mutation and deficiencies in mismatch repair. Notably, we also discover that wild-type Pol ε has a sevenfold higher error rate when replicating 5mCpG compared to C in other contexts. Together, our results from PER-seq and human cancers demonstrate that replication errors are a major contributor to CpG>TpG mutagenesis in replicating cells, fundamentally changing our understanding of this important disease-causing mutational mechanism
Quercetin abrogates chemoresistance in melanoma cells by modulating ΔNp73
<p>Abstract</p> <p>Background</p> <p>The alkylating agent Dacarbazine (DTIC) has been used in the treatment of melanoma for decades, but when used as a monotherapy for cancer only moderate response rates are achieved. Recently, the clinical use of Temozolomide (TMZ) has become the more commonly used analog of DTIC-related oral agents because of its greater bioavailability and ability to cross the blood brain barrier. The response rates achieved by TMZ are also unsatisfactory, so there is great interest in identifying compounds that could be used in combination therapy. We have previously demonstrated that the bioflavonoid quercetin (Qct) promoted a p53-mediated response and sensitized melanoma to DTIC. Here we demonstrate that Qct also sensitizes cells to TMZ and propose a mechanism that involves the modulation of a truncated p53 family member, ΔNp73.</p> <p>Methods</p> <p>DB-1 melanoma (p53 wildtype), and SK Mel 28 (p53 mutant) cell lines were treated with TMZ (400 μM) for 48 hrs followed by Qct (75 μM) for 24 hrs. Cell death was determined by Annexin V-FITC staining and immunocytochemical analysis was carried out to determine protein translocation.</p> <p>Results</p> <p>After treatment with TMZ, DB-1 cells demonstrated increased phosphorylation of Ataxia telangiectasia mutated (ATM) and p53. However, the cells were resistant to TMZ-induced apoptosis and the resistance was associated with an increase in nuclear localization of ΔNp73. Qct treatment in combination with TMZ abolished drug insensitivity and caused a more than additive induction of apoptosis compared to either treatment alone. Treatment with Qct, caused redistribution of ΔNp73 into the cytoplasm and nucleus, which has been associated with increased p53 transcriptional activity. Knockdown of ΔNp73 restored PARP cleavage in the TMZ treated cells, confirming its anti-apoptotic role. The response to treatment was predominantly p53 mediated as the p53 mutant SK Mel 28 cells showed no significant enhancement of apoptosis.</p> <p>Conclusion</p> <p>This study demonstrates that Qct can sensitize cells to TMZ and that the mechanisms of sensitization involve modulation of p53 family members.</p
E-consultation and the quest for inclusive governance in Nigeria
Inclusive governance through public consultation is fundamental to
sustainable development as reiterated in the SDG16. Citizens’ consultation in the
policy planning and determination enhances the quality of policy outcomes and
help to build public trust in political institutions. Traditional institutions for public
consultation are however, often limited thus, policy decisions are in most cases, at
variance with public aspirations. The consequence is a growing public cynicism of
governmental institutions. To address this democratic decline, governments across
the world are now utilizing ICT tools to better consult with citizens in the public
policy process. This paper which adopts a mixture of descriptive and analytical
research designs engages a systematic literature review for collecting and analysing
data. The aim is to investigate the adoption of ICTs as tools for public consultation
to enhance inclusive governance in Nigeria. Findings reveal among others that the
increase in acceptance and usage of mobile technologies in the face of the challenges
of infrastructure, energy instability and low level of ICT literacy among others, provide veritable platform for e-consultation. E-consultation brings to bear
the equally important bottom-up approach in policy making by providing additional
channel for greater public voice in the policy-making process. E-consultation thus
poses to be cardinal to achieving sustainable development goal of just, peaceful
and inclusive societies in Nigeria
The Schnitzler syndrome
The Schnitzler syndrome is a rare and underdiagnosed entity which is considered today as being a paradigm of an acquired/late onset auto-inflammatory disease. It associates a chronic urticarial skin rash, corresponding from the clinico-pathological viewpoint to a neutrophilic urticarial dermatosis, a monoclonal IgM component and at least 2 of the following signs: fever, joint and/or bone pain, enlarged lymph nodes, spleen and/or liver, increased ESR, increased neutrophil count, abnormal bone imaging findings. It is a chronic disease with only one known case of spontaneous remission. Except of the severe alteration of quality of life related mainly to the rash, fever and pain, complications include severe inflammatory anemia and AA amyloidosis. About 20% of patients will develop a lymphoproliferative disorder, mainly Waldenström disease and lymphoma, a percentage close to other patients with IgM MGUS. It was exceedingly difficult to treat patients with this syndrome until the IL-1 receptor antagonist anakinra became available. Anakinra allows a complete control of all signs within hours after the first injection, but patients need continuous treatment with daily injections
Meta-analysis of archived DNA microarrays identifies genes regulated by hypoxia and involved in a metastatic phenotype in cancer cells
<p>Abstract</p> <p>Background</p> <p>Metastasis is a major cancer-related cause of death. Recent studies have described metastasis pathways. However, the exact contribution of each pathway remains unclear. Another key feature of a tumor is the presence of hypoxic areas caused by a lack of oxygen at the center of the tumor. Hypoxia leads to the expression of pro-metastatic genes as well as the repression of anti-metastatic genes. As many Affymetrix datasets about metastasis and hypoxia are publicly available and not fully exploited, this study proposes to re-analyze these datasets to extract new information about the metastatic phenotype induced by hypoxia in different cancer cell lines.</p> <p>Methods</p> <p>Affymetrix datasets about metastasis and/or hypoxia were downloaded from GEO and ArrayExpress. AffyProbeMiner and GCRMA packages were used for pre-processing and the Window Welch <it>t </it>test was used for processing. Three approaches of meta-analysis were eventually used for the selection of genes of interest.</p> <p>Results</p> <p>Three complementary approaches were used, that eventually selected 183 genes of interest. Out of these 183 genes, 99, among which the well known <it>JUNB</it>, <it>FOS </it>and <it>TP63</it>, have already been described in the literature to be involved in cancer. Moreover, 39 genes of those, such as <it>SERPINE1 </it>and <it>MMP7</it>, are known to regulate metastasis. Twenty-one genes including <it>VEGFA </it>and <it>ID2 </it>have also been described to be involved in the response to hypoxia. Lastly, DAVID classified those 183 genes in 24 different pathways, among which 8 are directly related to cancer while 5 others are related to proliferation and cell motility. A negative control composed of 183 random genes failed to provide such results. Interestingly, 6 pathways retrieved by DAVID with the 183 genes of interest concern pathogen recognition and phagocytosis.</p> <p>Conclusion</p> <p>The proposed methodology was able to find genes actually known to be involved in cancer, metastasis and hypoxia and, thus, we propose that the other genes selected based on the same methodology are of prime interest in the metastatic phenotype induced by hypoxia.</p
Cancer Biomarker Discovery: The Entropic Hallmark
Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases
The relationship between DNA modifications and mutations in cancer
Somatic mutations are the main triggers that initiate the formation of cancer. Large sequencing data sets in recent years revealed a substantial number of mutational processes, many of which are poorly understood or of completely unknown aetiology. These mutational processes leave characteristic sequence patterns, often called "signatures", in the DNA. Characterisation of the mutational patterns observed in cancer patients with respect to different genomic features and processes can help to unravel the aetiology and mechanisms of mutagenesis. Here, we explored the effects of DNA modifications and DNA replication on mutagenesis. The most common mutation type, C&GT;T mutations in a CpG context, is thought to result from spontaneous deamination of 5-methylcytosine (5mC), the major DNA modification. Much less is known about the mutational properties of the second most frequent modification, 5-hydroxymethylcytosine (5hmC). Integrating multiple genomic data sets, we demonstrate a twofold lower mutagenicity of 5hmC compared to 5mC, present across multiple tissues. Subsequently, we show how DNA modifications may modulate various mutational processes. In addition to spontaneous deamination of 5mC, our analysis suggests a key role of replication in CpG>TpG mutagenesis in patients deficient in post-replicative proofreading or repair, and possibly also in other cancer patients. Together with an analysis of mutation patterns observed in cancers exposed to UV light, tobacco smoke, or editing by APOBEC enzymes, the results show that the role of DNA modifications goes beyond the well-known spontaneous deamination of 5mC. Finally, we explored which of the known mutational processes might be modulated by DNA replication. We developed a novel method to quantify the magnitude of strand asymmetry of different mutational signatures in individual patients followed by evaluation of these exposures in early and late replicating regions. More than 75 % of mutational signatures exhibited a significant replication strand asymmetry or correlation with replication timing. The analysis gives new insights into mechanisms of mutagenicity in multiple signatures, particularly the so far enigmatic signature 17, where we suggest an involvement of oxidative damage in its aetiology. In conclusion, our results suggest that DNA replication or replication-associated DNA repair interacts with most mutagenic processes.</p
DNA modifications: naturally more error prone?
Epigenetic DNA modifications are essential for normal cell function in vertebrates, but they can also be hotspots of mutagenesis. Methylcytosine in particular has long been known to be less stable than other nucleotides and spontaneously deaminates to thymine. Beyond this well-established phenomenon, however, the influence of epigenetic marks on mutagenesis has recently become an active field of investigation. In this review, we summarize current knowledge of the interactions between different DNA modifications and other mutagenic processes. External mutagens, such as UV light or smoking carcinogens, affect modified cytosines differently from unmodified ones, and modified cytosine can in some cases be protective rather than mutagenic. Notably, cell-intrinsic processes, such as DNA replication, also appear to influence the mutagenesis of modified cytosines. Altogether, evidence is accumulating to show that epigenetic changes have a profound influence on tissue-specific mutation accumulation
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