58 research outputs found
Detection and metabolic investigations of a novel designer steroid: 3-chloro-17α-methyl-5α-androstan-17β-ol
In 2012, seized capsules containing white powder were analyzed to show the presence of unknown steroid-related compounds. Subsequent gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) investigations identified a mixture of 3α- and 3β- isomers of the novel compound; 3-chloro-17α-methyl-α-androstan-17β-ol. Synthesis of authentic reference materials followed by comparison of NMR, GC-MS and gas chromatography-tandem mass spectrometry (GC-MS/MS) data confirmed the finding of a new ‘designer’ steroid. Furthermore, in vitro androgen bioassays showed potent activity highlighting the potential for doping using this steroid. Due to the potential toxicity of the halogenated steroid, in vitro metabolic investigations of 3α-chloro-17α-methyl-α-androstan-17β-ol using equine and human S9 liver fractions were performed. For equine, GC-MS/MS analysis identified the diagnostic 3α-chloro-17α-methyl-5α-androstane-16α,17β-diol metabolite. For human, the 17α-methyl-α-androstane-3α,17β-diol metabolite was found. Results from these studies were used to verify the ability of GC-MS/MS precursor-ion scanning techniques to support untargeted detection strategies for designer steroids in anti-doping analyses.Synthesis and in vitro metabolic investigations of 3α/β-chloro-17α-methyl-5α-androstan -17β-ol was suppo rted by the Austr a-lian Research Council Linkage Grant (LP120200444) Strat egies for the detection of designer ster oids in ra cehorses
MTL-CEBPA, a Small Activating RNA Therapeutic Upregulating C/EBP-α, in Patients with Advanced Liver Cancer: A First-in-Human, Multicenter, Open-Label, Phase I Trial.
PURPOSE: Transcription factor C/EBP-α (CCAAT/enhancer-binding protein alpha) acts as a master regulator of hepatic and myeloid functions and multiple oncogenic processes. MTL-CEBPA is a first-in-class small activating RNA oligonucleotide drug that upregulates C/EBP-α. PATIENTS AND METHODS: We conducted a phase I, open-label, dose-escalation trial of MTL-CEBPA in adults with advanced hepatocellular carcinoma (HCC) with cirrhosis, or resulting from nonalcoholic steatohepatitis or with liver metastases. Patients received intravenous MTL-CEBPA once a week for 3 weeks followed by a rest period of 1 week per treatment cycle in the dose-escalation phase (3+3 design). RESULTS: Thirty-eight participants have been treated across six dose levels (28-160 mg/m2) and three dosing schedules. Thirty-four patients were evaluable for safety endpoints at 28 days. MTL-CEBPA treatment-related adverse events were not associated with dose, and no maximum dose was reached across the three schedules evaluated. Grade 3 treatment-related adverse events occurred in nine (24%) patients. In 24 patients with HCC evaluable for efficacy, an objective tumor response was achieved in one patient [4%; partial response (PR) for over 2 years] and stable disease (SD) in 12 (50%). After discontinuation of MTL-CEBPA, seven patients were treated with tyrosine kinase inhibitors (TKIs); three patients had a complete response with one further PR and two with SD. CONCLUSIONS: MTL-CEBPA is the first saRNA in clinical trials and demonstrates an acceptable safety profile and potential synergistic efficacy with TKIs in HCC. These encouraging phase I data validate targeting of C/EBP-α and have prompted MTL-CEBPA + sorafenib combination studies in HCC
Meeting Report: Validation of Toxicogenomics-Based Test Systems: ECVAM–ICCVAM/NICEATM Considerations for Regulatory Use
This is the report of the first workshop “Validation of Toxicogenomics-Based Test Systems” held 11–12 December 2003 in Ispra, Italy. The workshop was hosted by the European Centre for the Validation of Alternative Methods (ECVAM) and organized jointly by ECVAM, the U.S. Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM), and the National Toxicology Program (NTP) Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM). The primary aim of the workshop was for participants to discuss and define principles applicable to the validation of toxicogenomics platforms as well as validation of specific toxicologic test methods that incorporate toxicogenomics technologies. The workshop was viewed as an opportunity for initiating a dialogue between technologic experts, regulators, and the principal validation bodies and for identifying those factors to which the validation process would be applicable. It was felt that to do so now, as the technology is evolving and associated challenges are identified, would be a basis for the future validation of the technology when it reaches the appropriate stage. Because of the complexity of the issue, different aspects of the validation of toxicogenomics-based test methods were covered. The three focus areas include a) biologic validation of toxicogenomics-based test methods for regulatory decision making, b) technical and bioinformatics aspects related to validation, and c) validation issues as they relate to regulatory acceptance and use of toxicogenomics-based test methods. In this report we summarize the discussions and describe in detail the recommendations for future direction and priorities
Acute tumor response to ZD6126 assessed by intrinsic susceptibility magnetic resonance imaging
AbstractThe effective magnetic resonance imaging (MRI) transverse relaxation rate R2* was investigated as an early acute marker of the response of rat GH3 prolactinomas to the vascular-targeting agent, ZD6126. Multigradient echo (MGRE) MRI was used to quantify R2*, which is sensitive to tissue deoxyhemoglobin levels. Tumor R2* was measured prior to, and either immediately for up to 35 minutes, or 24 hours following administration of 50 mg/kg ZD6126. Following MRI, tumor perfusion was assessed by Hoechst 33342 uptake. Tumor R2* significantly increased to 116 ± 4% of baseline 35 minutes after challenge, consistent with an ischemic insult induced by vascular collapse. A strong positive correlation between baseline R2* and the subsequent increase in R2* measured 35 minutes after treatment was obtained, suggesting that the baseline R2* is prognostic for the subsequent tumor response to ZD6126. In contrast, a significant decrease in tumor R2* was found 24 hours after administration of ZD6126. Both the 35-minute and 24-hour R2* responses to ZD6126 were associated with a decrease in Hoechst 33342 uptake. Interpretation of the R2* response is complex, yet changes in tumor R2* may provide a convenient and early MRI biomarker for detecting the antitumor activity of vascular-targeting agents
Construing the child reader: a cognitive stylistic analysis of the opening to Neil Gaiman’s The Graveyard Book
Neil Gaiman’s The Graveyard Book (2009) charts the story of Nobody Owens, a boy who is adopted by supernatural entities in the local graveyard after his family is murdered. This article draws on the notion of the “construed reader,” and combines two cognitive stylistic frameworks to analyse the opening section of the novel. In doing so, the article explores the representation and significance of the family home in relation to what follows in the narrative. The analysis largely draws on Text World Theory (Werth, 1999; Gavins, 2007), but also integrates some aspects of Cognitive Grammar (Langacker, 2008), which allows for a more nuanced discussion of textual features. The article pays particular attention to the way Gaiman frames his narrative and positions his reader to view the fictional events from a distinctive vantage point and subsequently demonstrates that a stylistic analysis of children’s literature can lay bare how such writing is designed with a young readership in mind
Singing the same tune? International continuities and discontinuities in how police talk about using force
This article focuses on a research project conducted in six jurisdictions: England, The Netherlands, Germany, Australia, Venezuela, and Brazil. These societies are very different ethnically, socially, politically, economically, historically and have wildly different levels of crime. Their policing arrangements also differ significantly: how they are organised; how their officers are equipped and trained; what routine operating procedures they employ; whether they are armed; and much else besides. Most relevant for this research, they represent policing systems with wildly different levels of police shootings, Police in the two Latin American countries represented here have a justified reputation for the frequency with which they shoot people, whereas at the other extreme the police in England do not routinely carry firearms and rarely shoot anyone. To probe whether these differences are reflected in the way that officers talk about the use of force, police officers in these different jurisdictions were invited to discuss in focus groups a scenario in which police are thwarted in their attempt to arrest two youths (one of whom is a known local criminal) by the youths driving off with the police in pursuit, and concludes with the youths crashing their car and escaping in apparent possession of a gun, It might be expected that focus groups would prove starkly different, and indeed they were, but not in the way that might be expected. There was little difference in affirmation of normative and legal standards regarding the use of force. It was in how officers in different jurisdictions envisaged the circumstances in which the scenario took place that led Latin American officers to anticipate that they would shoot the suspects, whereas officers in the other jurisdictions had little expectation that they would open fire in the conditions as they imagined them to be
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study
Background
The SARS-CoV-2 variant B.1.1.7 was first identified in December, 2020, in England. We aimed to investigate whether increases in the proportion of infections with this variant are associated with differences in symptoms or disease course, reinfection rates, or transmissibility.
Methods
We did an ecological study to examine the association between the regional proportion of infections with the SARS-CoV-2 B.1.1.7 variant and reported symptoms, disease course, rates of reinfection, and transmissibility. Data on types and duration of symptoms were obtained from longitudinal reports from users of the COVID Symptom Study app who reported a positive test for COVID-19 between Sept 28 and Dec 27, 2020 (during which the prevalence of B.1.1.7 increased most notably in parts of the UK). From this dataset, we also estimated the frequency of possible reinfection, defined as the presence of two reported positive tests separated by more than 90 days with a period of reporting no symptoms for more than 7 days before the second positive test. The proportion of SARS-CoV-2 infections with the B.1.1.7 variant across the UK was estimated with use of genomic data from the COVID-19 Genomics UK Consortium and data from Public Health England on spike-gene target failure (a non-specific indicator of the B.1.1.7 variant) in community cases in England. We used linear regression to examine the association between reported symptoms and proportion of B.1.1.7. We assessed the Spearman correlation between the proportion of B.1.1.7 cases and number of reinfections over time, and between the number of positive tests and reinfections. We estimated incidence for B.1.1.7 and previous variants, and compared the effective reproduction number, Rt, for the two incidence estimates.
Findings
From Sept 28 to Dec 27, 2020, positive COVID-19 tests were reported by 36 920 COVID Symptom Study app users whose region was known and who reported as healthy on app sign-up. We found no changes in reported symptoms or disease duration associated with B.1.1.7. For the same period, possible reinfections were identified in 249 (0·7% [95% CI 0·6–0·8]) of 36 509 app users who reported a positive swab test before Oct 1, 2020, but there was no evidence that the frequency of reinfections was higher for the B.1.1.7 variant than for pre-existing variants. Reinfection occurrences were more positively correlated with the overall regional rise in cases (Spearman correlation 0·56–0·69 for South East, London, and East of England) than with the regional increase in the proportion of infections with the B.1.1.7 variant (Spearman correlation 0·38–0·56 in the same regions), suggesting B.1.1.7 does not substantially alter the risk of reinfection. We found a multiplicative increase in the Rt of B.1.1.7 by a factor of 1·35 (95% CI 1·02–1·69) relative to pre-existing variants. However, Rt fell below 1 during regional and national lockdowns, even in regions with high proportions of infections with the B.1.1.7 variant.
Interpretation
The lack of change in symptoms identified in this study indicates that existing testing and surveillance infrastructure do not need to change specifically for the B.1.1.7 variant. In addition, given that there was no apparent increase in the reinfection rate, vaccines are likely to remain effective against the B.1.1.7 variant.
Funding
Zoe Global, Department of Health (UK), Wellcome Trust, Engineering and Physical Sciences Research Council (UK), National Institute for Health Research (UK), Medical Research Council (UK), Alzheimer's Society
Genomic assessment of quarantine measures to prevent SARS-CoV-2 importation and transmission
Mitigation of SARS-CoV-2 transmission from international travel is a priority. We evaluated the effectiveness of travellers being required to quarantine for 14-days on return to England in Summer 2020. We identified 4,207 travel-related SARS-CoV-2 cases and their contacts, and identified 827 associated SARS-CoV-2 genomes. Overall, quarantine was associated with a lower rate of contacts, and the impact of quarantine was greatest in the 16–20 age-group. 186 SARS-CoV-2 genomes were sufficiently unique to identify travel-related clusters. Fewer genomically-linked cases were observed for index cases who returned from countries with quarantine requirement compared to countries with no quarantine requirement. This difference was explained by fewer importation events per identified genome for these cases, as opposed to fewer onward contacts per case. Overall, our study demonstrates that a 14-day quarantine period reduces, but does not completely eliminate, the onward transmission of imported cases, mainly by dissuading travel to countries with a quarantine requirement
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