A critical question facing the field of metabolomics is whether data obtained from different centers can be effectively compared and combined. An important aspect of this is the interlaboratory ...precision (reproducibility) of the analytical protocols used. We analyzed human samples in six laboratories using different instrumentation but a common protocol (the AbsoluteIDQ p180 kit) for the measurement of 189 metabolites via liquid chromatography (LC) or flow injection analysis (FIA) coupled to tandem mass spectrometry (MS/MS). In spiked quality control (QC) samples 82% of metabolite measurements had an interlaboratory precision of <20%, while 83% of averaged individual laboratory measurements were accurate to within 20%. For 20 typical biological samples (serum and plasma from healthy individuals) the median interlaboratory coefficient of variation (CV) was 7.6%, with 85% of metabolites exhibiting a median interlaboratory CV of <20%. Precision was largely independent of the type of sample (serum or plasma) or the anticoagulant used but was reduced in a sample from a patient with dyslipidaemia. The median interlaboratory accuracy and precision of the assay for standard reference plasma (NIST SRM 1950) were 107% and 6.7%, respectively. Likely sources of irreproducibility were the near limit of detection (LOD) typical abundance of some metabolites and the degree of manual review and optimization of peak integration in the LC-MS/MS data after acquisition. Normalization to a reference material was crucial for the semi-quantitative FIA measurements. This is the first interlaboratory assessment of a widely used, targeted metabolomics assay illustrating the reproducibility of the protocol and how data generated on different instruments could be directly integrated in large-scale epidemiological studies.
Studying Mobile Media Hjorth, Larissa; Burgess, Jean; Richardson, Ingrid
2012, 20120423, 2012-03-26, 2012-04-23, Volume:
39
eBook
The iPhone represents an important moment in both the short history of mobile media and the long history of cultural technologies. Like the Walkman of the 1980s, it marks a juncture in which notions ...about identity, individualism, lifestyle and sociality require rearticulation. this book explores not only the iPhone's particular characteristics, uses and "affects," but also how the "iPhone moment" functions as a barometer for broader patterns of change. In the iPhone moment, this study considers the convergent trajectories in the evolution of digital and mobile culture, and their implications for future scholarship. Through the lens of the iPhone-as a symbol, culture and a set of material practices around contemporary convergent mobile media-the essays collected here explore the most productive theoretical and methodological approaches for grasping media practice, consumer culture and networked communication in the twenty-first century.
At high altitude oxygen delivery to the tissues is impaired leading to oxygen insufficiency (hypoxia). Acclimatisation requires adjustment to tissue metabolism, the details of which remain ...incompletely understood. Here, metabolic responses to progressive environmental hypoxia were assessed through metabolomic and lipidomic profiling of human plasma taken from 198 human participants before and during an ascent to Everest Base Camp (5,300 m). Aqueous and lipid fractions of plasma were separated and analysed using proton (
H)-nuclear magnetic resonance spectroscopy and direct infusion mass spectrometry, respectively. Bayesian robust hierarchical regression revealed decreasing isoleucine with ascent alongside increasing lactate and decreasing glucose, which may point towards increased glycolytic rate. Changes in the lipid profile with ascent included a decrease in triglycerides (48-50 carbons) associated with de novo lipogenesis, alongside increases in circulating levels of the most abundant free fatty acids (palmitic, linoleic and oleic acids). Together, this may be indicative of fat store mobilisation. This study provides the first broad metabolomic account of progressive exposure to environmental hypobaric hypoxia in healthy humans. Decreased isoleucine is of particular interest as a potential contributor to muscle catabolism observed with exposure to hypoxia at altitude. Substantial changes in lipid metabolism may represent important metabolic responses to sub-acute exposure to environmental hypoxia.
The objective of the present study was to investigate associations between sugar intake and overweight using dietary biomarkers in the Norfolk cohort of the European Prospective Investigation into ...Cancer and Nutrition (EPIC-Norfolk).
Prospective cohort study.
EPIC-Norfolk in the UK, recruitment between 1993 and 1997.
Men and women (n 1734) aged 39-77 years. Sucrose intake was assessed using 7 d diet diaries. Baseline spot urine samples were analysed for sucrose by GC-MS. Sucrose concentration adjusted by specific gravity was used as a biomarker for intake. Regression analyses were used to investigate associations between sucrose intake and risk of BMI>25·0 kg/m2 after three years of follow-up.
After three years of follow-up, mean BMI was 26·8 kg/m2. Self-reported sucrose intake was significantly positively associated with the biomarker. Associations between the biomarker and BMI were positive (β=0·25; 95 % CI 0·08, 0·43), while they were inverse when using self-reported dietary data (β=-1·40; 95 % CI -1·81, -0·99). The age- and sex-adjusted OR for BMI>25·0 kg/m2 in participants in the fifth v. first quintile was 1·54 (95 % CI 1·12, 2·12; P trend=0·003) when using biomarker and 0·56 (95 % CI 0·40, 0·77; P trend<0·001) with self-reported dietary data.
Our results suggest that sucrose measured by objective biomarker but not self-reported sucrose intake is positively associated with BMI. Future studies should consider the use of objective biomarkers of sucrose intake.
This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. Social, casual and mobile games, played on devices such as ...smartphones, tablets, or PCs and accessed through online social networks, have become extremely popular, and are changing the ways in which games are designed, understood, and played. These games have sparked a revolution as more people from a broader demographic than ever play games, shifting the stereotype of gaming away from that of hardcore, dedicated play to that of activities that fit into everyday life. Social, Casual and Mobile Games explores the rapidly changing gaming landscape and discusses the ludic, methodological, theoretical, economic, social and cultural challenges that these changes invoke. With chapters discussing locative games, the new freemium economic model, and gamer demographics, as well as close studies of specific games (including Candy Crush Saga, Angry Birds, and Ingress), this collection offers an insight into the changing nature of games and the impact that mobile media is having upon individuals and societies around the world.
In this article, we explore the material, sensory and corporeal aspects of digital ethnography, primarily in the context of mobile media use in the domestic environment. We align our methodological ...approach to the ‘sensory turn’ in theory, situated loosely under the rubric of new materialism, and outline the insights that a post-phenomenological method can offer. Drawing from our current research into everyday media use conducted within Australian households, which involved a range of data collection methods aimed at capturing the embodiment of mobile media, we explore the significance of play in and around haptic interfaces. Mobile games are evidently integral to our embodied ways of knowing, and there are a number of challenges faced by the mobile media researcher who seeks to document, understand and interpret this contemporary cultural and everyday practice.
This special commentary for Mobile Media & Communication seeks to put these divisive debates in context. Through the lens of Pokémon GO, we can understand and critically interpret a variety of issues ...involved in the politics and practice of playful mobile media. These issues move across debates around location-aware technologies in constructions of privacy (Coldewey, 2016; Cunningham, 2016), risk and surveillance (Machkovech, 2016; Mishra, 2016) to the role of mobile media in commodifying (Evangelho, 2016) and expanding the social, cultural, and creative dimensions of play (Isbister, 2016; Mäyrä, 2012). As the mobile media and game theorists in this commentary highlight, the game sits at the nexus of several technological and cultural trajectories: the playful turn; the ubiquity of location-based and haptic mobile media (and apps and games); innovative game design; the effects of digital mapping technologies; the intertwining of performative media games and art; our individual and collective memories of playworlds and transmedia universes; the increasing importance of issues concerning privacy and risk in public spaces; the ongoing augmentation of place and space; and the politics embedded in this hybrid experience of the lifeworld.
Internalization from the cell membrane and endosomal trafficking of receptor tyrosine kinases (RTKs) are important regulators of signaling in normal cells that can frequently be disrupted in cancer. ...The adrenal tumor pheochromocytoma (PCC) can be caused by activating mutations of the rearranged during transfection (RET) receptor tyrosine kinase, or inactivation of TMEM127, a transmembrane tumor suppressor implicated in trafficking of endosomal cargos. However, the role of aberrant receptor trafficking in PCC is not well understood. Here, we show that loss of TMEM127 causes wildtype RET protein accumulation on the cell surface, where increased receptor density facilitates constitutive ligand-independent activity and downstream signaling, driving cell proliferation. Loss of TMEM127 altered normal cell membrane organization and recruitment and stabilization of membrane protein complexes, impaired assembly, and maturation of clathrin-coated pits, and reduced internalization and degradation of cell surface RET. In addition to RTKs, TMEM127 depletion also promoted surface accumulation of several other transmembrane proteins, suggesting it may cause global defects in surface protein activity and function. Together, our data identify TMEM127 as an important determinant of membrane organization including membrane protein diffusability and protein complex assembly and provide a novel paradigm for oncogenesis in PCC where altered membrane dynamics promotes cell surface accumulation and constitutive activity of growth factor receptors to drive aberrant signaling and promote transformation.
Sorafenib remains the only approved drug for treating patients with advanced hepatocellular carcinoma (HCC). However, the therapeutic effect of sorafenib is transient, and patients invariably develop ...sorafenib resistance (SR). Recently, TYRO3, a member of the TYRO3‐AXL‐MER family of receptor tyrosine kinases, was identified as being aberrantly expressed in a significant proportion of HCC; however, its role in SR is unknown. In this study, we generated two functionally distinct sorafenib‐resistant human Huh‐7 HCC cell lines in order to identify new mechanisms to abrogate acquired SR as well as new potential therapeutic targets in HCC. Initially, we investigated the effects of a microRNA (miR), miR‐7‐5p (miR‐7), in both in vitro and in vivo preclinical models of human HCC and identified miR‐7 as a potent tumor suppressor of human HCC. We identified TYRO3 as a new functional target of miR‐7, which regulates proliferation, migration, and invasion of Huh‐7 cells through the phosphoinositide 3‐kinase/protein kinase B pathway and is markedly elevated with acquisition of SR. Furthermore, miR‐7 effectively silenced TYRO3 expression in both sorafenib‐sensitive and sorafenib‐resistant Huh‐7 cells, inhibiting TYRO3/growth arrest specific 6‐mediated cancer cell migration and invasion. Conclusion: We identified a mechanism for acquiring SR in HCC that is through the aberrant expression of the TYRO3/phosphoinositide 3‐kinase/protein kinase B signal transduction pathway, and that can be overcome by miR‐7 overexpression. Taken together, these data suggest a potential role for miR‐7 as an RNA‐based therapeutic to treat refractory and drug‐resistant HCC. (Hepatology 2018;67:216‐231)
To examine the in vitro and in vivo efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in treatment of PIK3CA wild-type colorectal cancer (CRC).
PIK3CA mutant and wild-type human CRC cell lines were ...treated in vitro with NVP-BEZ235, and the resulting effects on proliferation, apoptosis, and signaling were assessed. Colonic tumors from a genetically engineered mouse (GEM) model for sporadic wild-type PIK3CA CRC were treated in vivo with NVP-BEZ235. The resulting effects on macroscopic tumor growth/regression, proliferation, apoptosis, angiogenesis, and signaling were examined.
In vitro treatment of CRC cell lines with NVP-BEZ235 resulted in transient PI3K blockade, sustained decreases in mTORC1/mTORC2 signaling, and a corresponding decrease in cell viability (median IC(50) = 9.0-14.3 nM). Similar effects were seen in paired isogenic CRC cell lines that differed only in the presence or absence of an activating PIK3CA mutant allele. In vivo treatment of colonic tumor-bearing mice with NVP-BEZ235 resulted in transient PI3K inhibition and sustained blockade of mTORC1/mTORC2 signaling. Longitudinal tumor surveillance by optical colonoscopy demonstrated a 97% increase in tumor size in control mice (p = 0.01) vs. a 43% decrease (p = 0.008) in treated mice. Ex vivo analysis of the NVP-BEZ235-treated tumors demonstrated a 56% decrease in proliferation (p = 0.003), no effects on apoptosis, and a 75% reduction in angiogenesis (p = 0.013).
These studies provide the preclinical rationale for studies examining the efficacy of the dual PI3K/mTOR inhibitor NVP-BEZ235 in treatment of PIK3CA wild-type CRC.
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