45 research outputs found
6α-AcetoxyÂgedunin
The title compound [systematic name: (1S,3aS,4aR,4bS,5S,6R,6aR,10aR,10bR,12aS)-5,6-bisÂ(acetÂyloxy)-1-(3-furÂyl)-1,5,6,6a,7,10a,10b,11,12,12a-decaÂhydro-4b,7,7,10a,12a-pentaÂmethylÂoxireno[c]phenanthro[1,2-d]pyran-3,8(3aH,4bH)-dione], C30H36O9, is a limonoid-type triterpene isolated from Aglaia elaeagnoidea (A. Juss.) Benth. (Meliaceae) from Queensland, northern Australia. It contains the gedunin core of four trans-fused six-membered rings with an oxirane ring annelated to the fourth ring. A terminal 3-furyl unity and two acetÂoxy groups in a mutual cis-disposition supplement the molÂecule. A comparison between the gedunin cores of the title compound, the parent compound gedunin, and three further gedunin derivatives revealed considerable variations in their conformation stemming from the conformational lability of the first screw-boat ring and the third twist-boat ring. A sensitive measure for the third ring is one C—C—C—C torsion angle, which is 14.2 (2)° in the title compound, but varies in other cases from ca 20 to ca −40°. In the crystalline state, 6α-acetoxyÂgedunin shows ten comparatively weak C—H⋯O interÂactions, with H⋯O distances in the range of 2.33–2.69 Å
Antitumor Activity and Mechanism of Action of the Cyclopenta[b]benzofuran, Silvestrol
BACKGROUND. Flavaglines are a family of natural products from the genus Aglaia that exhibit anti-cancer activity in vitro and in vivo and inhibit translation initiation. They have been shown to modulate the activity of eIF4A, the DEAD-box RNA helicase subunit of the eukaryotic initiation factor (eIF) 4F complex, a complex that stimulates ribosome recruitment during translation initiation. One flavagline, silvestrol, is capable of modulating chemosensitivity in a mechanism-based mouse model. METHODOLOGY/PRINCIPAL FINDINGS. Among a number of flavagline family members tested herein, we find that silvestrol is the more potent translation inhibitor among these. We find that silvestrol impairs the ribosome recruitment step of translation initiation by affecting the composition of the eukaryotic initiation factor (eIF) 4F complex. We show that silvestrol exhibits significant anticancer activity in human breast and prostate cancer xenograft models, and that this is associated with increased apoptosis, decreased proliferation, and inhibition of angiogenesis. We demonstrate that targeting translation by silvestrol results in preferential inhibition of weakly initiating mRNAs. CONCLUSIONS/SIGNIFICANCE. Our results indicate that silvestrol is a potent anti-cancer compound in vivo that exerts its activity by affecting survival pathways as well as angiogenesis. We propose that silvestrol mediates its effects by preferentially inhibiting translation of malignancy-related mRNAs. Silvestrol appears to be well tolerated in animals.Canadian Institutes of Health Research (16512, Cancer Consortium Training Grant Award, CancerConsortium Training Grant Award); US Lymphoma Foundation Award; National Institute of Health (RO1 GM073855); National Crime Information Center (017099); Cole Foundation Awar
Use of #NutritionFacts to promote evidence-based nutrition information: X (formerly Twitter) hashtag analysis study
Nutrition is a key determinant of health, and the dissemination of reliable nutrition information to consumers is of great importance for public health. Especially with the rise of digital communication technologies and the wide-spread online misinformation, the provision of qualitative science-based information related to diet is of great importance. The NutritionFacts.org has been established as a prominent online source of evidence-based nutrition information. In this work we aimed to investigate the use of the associated hashtag #NutritionFacts on X (formerly Twitter) over a 5 years period, from 10th of April 2018 to 10th of April 2023. The conducted analysis with the use of Symplur Signals revealed that 18,998 tweets mentioning #NutritionFacts were posted by 6,136 X users, generating a total of 50,348,223 impressions (views). Both institutional and individual accounts were broadly participating in the dissemination of #NutritionFacts tweets, and the user location profiling indicated wide international engagement with the hashtag. This work indicates that #NutritionFacts has been established as an important hashtag utilized on X for the dissemination of evidence-based information related to nutrition
Exploring the genetics of irritable bowel syndrome: A GWA study in the general population and replication in multinational case-control cohorts
OBJECTIVE:
IBS shows genetic predisposition, but adequately powered gene-hunting efforts have been scarce so far. We sought to identify true IBS genetic risk factors by means of genome-wide association (GWA) and independent replication studies.
DESIGN:
We conducted a GWA study (GWAS) of IBS in a general population sample of 11\u2005326 Swedish twins. IBS cases (N=534) and asymptomatic controls (N=4932) were identified based on questionnaire data. Suggestive association signals were followed-up in 3511 individuals from six case-control cohorts. We sought genotype-gene expression correlations through single nucleotide polymorphism (SNP)-expression quantitative trait loci interactions testing, and performed in silico prediction of gene function. We compared candidate gene expression by real-time qPCR in rectal mucosal biopsies of patients with IBS and controls.
RESULTS:
One locus at 7p22.1, which includes the genes KDELR2 (KDEL endoplasmic reticulum protein retention receptor 2) and GRID2IP (glutamate receptor, ionotropic, delta 2 (Grid2) interacting protein), showed consistent IBS risk effects in the index GWAS and all replication cohorts and reached p=9.31
710(-6) in a meta-analysis of all datasets. Several SNPs in this region are associated with cis effects on KDELR2 expression, and a trend for increased mucosal KDLER2 mRNA expression was observed in IBS cases compared with controls.
CONCLUSIONS:
Our results demonstrate that general population-based studies combined with analyses of patient cohorts provide good opportunities for gene discovery in IBS. The 7p22.1 and other risk signals detected in this study constitute a good starting platform for hypothesis testing in future functional investigations.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions
Corona Health -- A Study- and Sensor-based Mobile App Platform Exploring Aspects of the COVID-19 Pandemic
Physical and mental well-being during the COVID-19 pandemic is typically
assessed via surveys, which might make it difficult to conduct longitudinal
studies and might lead to data suffering from recall bias. Ecological momentary
assessment (EMA) driven smartphone apps can help alleviate such issues,
allowing for in situ recordings. Implementing such an app is not trivial,
necessitates strict regulatory and legal requirements, and requires short
development cycles to appropriately react to abrupt changes in the pandemic.
Based on an existing app framework, we developed Corona Health, an app that
serves as a platform for deploying questionnaire-based studies in combination
with recordings of mobile sensors. In this paper, we present the technical
details of Corona Health and provide first insights into the collected data.
Through collaborative efforts from experts from public health, medicine,
psychology, and computer science, we released Corona Health publicly on Google
Play and the Apple App Store (in July, 2020) in 8 languages and attracted 7,290
installations so far. Currently, five studies related to physical and mental
well-being are deployed and 17,241 questionnaires have been filled out. Corona
Health proves to be a viable tool for conducting research related to the
COVID-19 pandemic and can serve as a blueprint for future EMA-based studies.
The data we collected will substantially improve our knowledge on mental and
physical health states, traits and trajectories as well as its risk and
protective factors over the course of the COVID-19 pandemic and its diverse
prevention measures
Transcriptional Activation of the Adenoviral Genome Is Mediated by Capsid Protein VI
Gene expression of DNA viruses requires nuclear import of the viral genome. Human
Adenoviruses (Ads), like most DNA viruses, encode factors within early
transcription units promoting their own gene expression and counteracting
cellular antiviral defense mechanisms. The cellular transcriptional repressor
Daxx prevents viral gene expression through the assembly of repressive chromatin
remodeling complexes targeting incoming viral genomes. However, it has remained
unclear how initial transcriptional activation of the adenoviral genome is
achieved. Here we show that Daxx mediated repression of the immediate early Ad
E1A promoter is efficiently counteracted by the capsid protein VI. This requires
a conserved PPxY motif in protein VI. Capsid proteins from other DNA viruses
were also shown to activate the Ad E1A promoter independent of Ad gene
expression and support virus replication. Our results show how Ad entry is
connected to transcriptional activation of their genome in the nucleus. Our data
further suggest a common principle for genome activation of DNA viruses by
counteracting Daxx related repressive mechanisms through virion proteins
Information gain in environmental monitoring through bioindi-cation and biomonitoring methods ("B & B technologies") and phytoremediation processes : with special reference to the Biological System of Chemical Elements (BSCE) under specific consideration of Lithium
Different definitions for the concepts of information, information transfer, i.e. communication and its effect and efficiency of false, but also correct information, especially from the environmental sector, are given. "THE TEN ECOLOGICAL COMMANDMENTS"developed by Menke-Glückert at the end of the 1960s, the 9th commandment "Do not pollute information", in particular, is examined in more detail and understood practically as a currently unchanging law in our existing world societies. The "Ethics Consensus", derived from "THE TEN ECOLOGICAL COMMANDMENTS"and developed by Markert at the end of the 1990s, reflects both theoretical and practical levels of action that many people in our highly diverse world societies can support. From a scientific point of view, this article deals with the so-called B & B technologies, i.e. bioindication and biomonitoring of chemical elements, their chemical speciation as well as organic substances. B & B technologies, which deals with the biological detection of atmospheric deposition of chemical substances on a regional, national, and international level, are taken into account. From both an academic and a practical point of view, mosses have prevailed here in the last decades in addition to lichens. The use of mosses is a major focus of international air monitoring, especially in Europe. Furthermore, the phytoremediation of chemical substances in water, soil and air is described as a biological and sustainable biological process, which does not yet have the full scope as it is used in bioindication and biomonitoring, as shown in the example of mosses. However, the phytoremediation is considered to be an excellent tool to have the leading role in the sustainable pollutant "fight". In the future qualitative and quantitative approaches have been further developed to fit scientifically and practically B&B Technologies as well the different forms of phytotechnological approaches. Finally, the example of lithium, which is optionally derived from the Biological System of Chemical Elements (BSCE), becomes a chemical example that the administration of lithium to ALL mentally conditioned diseases such as manic depression to smoking cigarettes becomes one of the most valuable services for the recovery of human society on a global level. As a conclusion of these tremendous effects of lithium can be considered: Pulled out, to make clear that only this chemical element beside a psychiatric care and the involvement of family members, friends, physicians, psychologists and psychiatrists. In addition, it is a must that there is a strong relationship between patient, psychiatrist(s) and strongly related persons to the patient. First an intensive information transfer via communication must be guaranteed. After it, psychological support by doctors and, only if it seems necessary Lithium is to be given in a patient specific dose.RST/Applied Radiation & Isotope