1,133 research outputs found
Transmission Electron Microscopy Data on drusen-like deposits in the retinal degeneration sTg-IRBP : HEL mouse model
We are grateful to the Microscopy and Histology Core Facility of the University of Aberdeen for their assistance with sample processing. This work was generously funded by the charity Saving Sight in Grampian of the University of Aberdeen Development Trust.Peer reviewedPublisher PD
Evolving Role for Pharmacotherapy in NAFLD/NASH
Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent, dynamic disease that occurs across the age spectrum and can lead to cirrhosis and hepatocellular carcinoma. There are currently no US Food and Drug Administration (FDA) approved treatments for NAFLD; however, this is a field of active research. This review summarizes emerging pharmacotherapies for the treatment of adult and pediatric NAFLD. Investigated pharmacotherapies predominantly target bile acid signaling, insulin resistance, and lipid handling within the liver. Three drugs have gone on to phase III trials for which results are available. Of those, obeticholic acid is the single agent that demonstrates promise according to the interim analyses of the REGENERATE trial. Obeticholic acid showed reduction of fibrosis in adults with nonalcoholic steatohepatitis (NASH) taking 25 mg daily for 18 months (n = 931, reduction in fibrosis in 25% vs. 12% placebo, P \u3c 0.01). Ongoing phase III trials include REGENERATE and MAESTRO-NASH, which investigates thyroid hormone receptor-β agonist MGL-3196. Outcomes of promising phase II trials in adults with NASH are also available and those have investigated agents, including the fibroblast growth factor (FGF)19 analogue NGM282, the GLP1 agonist liraglutide, the FGF21 analogue Pegbelfermin, the sodium glucose co-transporter 2 inhibitor Empagliflozin, the ketohexokinase inhibitor PF-06835919, the acetyl-coenzyme A carboxylase inhibitor GS-0976, and the chemokine receptor antagonist Cenicriviroc. Completed and ongoing clinical trials emphasize the need for a more nuanced understanding of the phenotypes of subgroups within NAFLD that may respond to an individualized approach to pharmacotherapy
Repressor element-1 silencing transcription factor/neuronal restrictive silencer factor (REST/NRSF) can regulate HSV-1 immediate-early transcription via histone modification
<p>Abstract</p> <p>Background</p> <p>During primary infection of its human host, Herpes Simplex Virus Type-1 (HSV-1) establishes latency in neurons where the viral genome is maintained in a circular form associated with nucleosomes in a chromatin configration. During latency, most viral genes are silenced, although the molecular mechanisms responsible for this are unclear. We hypothesized that neuronal factors repress HSV-1 gene expression during latency. A search of the HSV-1 DNA sequence for potential regulatory elements identified a Repressor Element-1/Neuronal Restrictive Silencer Element (RE-1/NRSE) located between HSV-1 genes ICP22 and ICP4. We predicted that the Repressor Element Silencing Transcription Factor/Neuronal Restrictive Silencer Factor (REST/NRSF) regulates expression of ICP22 and ICP4.</p> <p>Results</p> <p>Transient cotransfection indicated that REST/NRSF inhibited the activity of both promoters. In contrast, cotransfection of a mutant form of REST/NRSF encoding only the DNA-binding domain of the protein resulted in less inhibition. Stably transformed cell lines containing episomal reporter plasmids with a chromatin structure showed that REST/NRSF specifically inhibited the ICP4 promoter, but not the ICP22 promoter. REST/NRSF inhibition of the ICP4 promoter was reversed by histone deacetylase (HDAC) inhibitor Trichostatin A (TSA). Additionally, chromatin immuno-precipitation (ChIP) assays indicated that the corepressor CoREST was recruited to the proximity of ICP4 promoter and that acetylation of histone H4 was reduced in the presence of REST/NRSF.</p> <p>Conclusion</p> <p>Since the ICP4 protein is a key transactivator of HSV-1 lytic cycle genes, these results suggest that REST/NRSF may have an important role in the establishment and/or maintenance of HSV-1 gene silencing during latency by targeting ICP4 expression.</p
Averages of Fourier coefficients of Siegel modular forms and representation of binary quadratic forms by quadratic forms in four variables
Let be a a negative discriminant and let vary over a set of
representatives of the integral equivalence classes of integral binary
quadratic forms of discriminant . We prove an asymptotic formula for for the average over of the number of representations of by an
integral positive definite quaternary quadratic form and obtain results on
averages of Fourier coefficients of linear combinations of Siegel theta series.
We also find an asymptotic bound from below on the number of binary forms of
fixed discriminant which are represented by a given quaternary form. In
particular, we can show that for growing a positive proportion of the
binary quadratic forms of discriminant is represented by the given
quaternary quadratic form.Comment: v5: Some typos correcte
Haemodynamic consequences of targeted single- and dual-site right ventricular pacing in adults with congenital heart disease undergoing surgical pulmonary valve replacement
Aims The purpose of this study was to create an epicardial electroanatomic map of the right ventricle (RV) and then apply post-operative-targeted single- and dual-site RV temporary pacing with measurement of haemodynamic parameters. Cardiac resynchronization therapy is an established treatment for symptomatic left ventricular (LV) dysfunction. In congenital heart disease, RV dysfunction is a common cause of morbidity—little is known regarding the potential benefits of CRT in this setting.
Methods and results Sixteen adults (age = 32 ± 8 years; 6 M, 10 F) with right bundle branch block (RBBB) and repaired tetralogy of Fallot (n = 8) or corrected congenital pulmonary stenosis (n = 8) undergoing surgical pulmonary valve replacement (PVR) for pulmonary regurgitation underwent epicardial RV mapping and haemodynamic assessment of random pacing configurations including the site of latest RV activation. The pre-operative pulmonary regurgitant fraction was 49 ± 10%; mean LV end-diastolic volume (EDV) 85 ± 19 mL/min/m2 and RVEDV 183 ± 89 mL/min/m2 on cardiac magnetic resonance imaging. The mean pre-operative QRS duration is 136 ± 26 ms. The commonest site of latest activation was the RV free wall and DDD pacing here alone or combined with RV apical pacing resulted in significant increases in cardiac output (CO) vs. AAI pacing (P < 0.01 all measures). DDDRV alternative site pacing significantly improved CO by 16% vs. AAI (P = 0.018), and 8.5% vs. DDDRV apical pacing (P = 0.02).
Conclusion Single-site RV pacing targeted to the region of latest activation in patients with RBBB undergoing PVR induces acute improvements in haemodynamics and supports the concept of ‘RV CRT’. Targeted pacing in such patients has therapeutic potential both post-operatively and in the long term
Distinct roles of Akt1 and Akt2 in regulating cell migration and epithelial–mesenchymal transition
The Akt family of kinases are activated by growth factors and regulate pleiotropic cellular activities. In this study, we provide evidence for isoform-specific positive and negative roles for Akt1 and -2 in regulating growth factor–stimulated phenotypes in breast epithelial cells. Insulin-like growth factor-I receptor (IGF-IR) hyperstimulation induced hyperproliferation and antiapoptotic activities that were reversed by Akt2 down-regulation. In contrast, Akt1 down-regulation in IGF-IR–stimulated cells promoted dramatic neomorphic effects characteristic of an epithelial–mesenchymal transition (EMT) and enhanced cell migration induced by IGF-I or EGF stimulation. The phenotypic effects of Akt1 down-regulation were accompanied by enhanced extracellular signal–related kinase (ERK) activation, which contributed to the induction of migration and EMT. Interestingly, down-regulation of Akt2 suppressed the EMT-like morphological conversion induced by Akt1 down-regulation in IGF-IR–overexpressing cells and inhibited migration in EGF-stimulated cells. These results highlight the distinct functions of Akt isoforms in regulating growth factor–stimulated EMT and cell migration, as well as the importance of Akt1 in cross-regulating the ERK signaling pathway
Estuary and sea-associated wetlands as final sink for organic pollutants: a case study in Sabah, Malaysia
Estuaries and sea-associated wetlands are the final destination for organic pollutants due to their chemical and physical properties. The current research studied Parai River and estuary adjacent to the southern South China Sea in Kota Kinabalu, Sabah. Six samples of surface sediment were taken during January 2012. The samples (top 3 cm) were extracted by Soxhlet using Dichloromethane, subjected to 2 steps of column chromatography for clean-up and fractionation followed by Gas Chromatography-Mass Spectrometry. The results indicated that the highest concentration of alkane in a full range of even and odd carbon numbers is dominant in the estuary and sea-associated wetland. Estuaries receive the highest level of suspended materials due to continuous interaction between marine saline and riverine fresh water. The high amount of Unresolved Complex Mixture (UCM) indicated an incomplete cycle of degradation and decomposition. Terrestrial input was the most dominant natural entry to the study area where C31/C19 ratio was employed. The study concluded that sea-associated wetlands around the estuary may act as the final sink of organic pollutants in the environmen
Treatment with FoxP3+ Antigen-Experienced T Regulatory Cells Arrests Progressive Retinal Damage in a Spontaneous Model of Uveitis
FUNDING: This work was funded by Fight for Sight, The Eye Charity (CSO project grant award: 3031-3032), and The Development Trust of the University of Aberdeen (Saving Sight in Grampian) (Grant codes: RG-12663 and RG-14251). ACKNOWLEDGMENTS: We thank the Iain Fraser Flow Cytometry core facility, and the Microscopy and Histology core facility of the University of Aberdeen.Peer reviewedPublisher PD
Validation of an integrated pedal desk and electronic behavior tracking platform
Background This study tested the validity of revolutions per minute (RPM) measurements from the Pennington Pedal Desk™. Forty-four participants (73 % female; 39 ± 11.4 years-old; BMI 25.8 ± 5.5 kg/m2 [mean ± SD]) completed a standardized trial consisting of guided computer tasks while using a pedal desk for approximately 20 min. Measures of RPM were concurrently collected by the pedal desk and the Garmin Vector power meter. After establishing the validity of RPM measurements with the Garmin Vector, we performed equivalence tests, quantified mean absolute percent error (MAPE), and constructed Bland–Altman plots to assess agreement between RPM measures from the pedal desk and the Garmin Vector (criterion) at the minute-by-minute and trial level (i.e., over the approximate 20 min trial period). Results The average (mean ± SD) duration of the pedal desk trial was 20.5 ± 2.5 min. Measures of RPM (mean ± SE) at the minute-by-minute (Garmin Vector: 54.8 ± 0.4 RPM; pedal desk: 55.8 ± 0.4 RPM) and trial level (Garmin Vector: 55.0 ± 1.7 RPM; pedal desk: 56.0 ± 1.7 RPM) were deemed equivalent. MAPE values for RPM measured by the pedal desk were small (minute-by-minute: 2.1 ± 0.1 %; trial: 1.8 ± 0.1 %) and no systematic relationships in error variance were evident by Bland–Altman plots. Conclusion The Pennington Pedal Desk™ provides a valid count of RPM, providing an accurate metric to promote usage
In-situ Optimized Substrate Witness Plates: Ground Truth for Key Processes on the Moon and Other Planets
Future exploration efforts of the Moon, Mars and other bodies are poised to
focus heavily on persistent and sustainable survey and research efforts,
especially given the recent interest in a long-term sustainable human presence
at the Moon. Key to these efforts is understanding a number of important
processes on the lunar surface for both scientific and operational purposes. We
discuss the potential value of in-situ artificial substrate witness plates,
powerful tools that can supplement familiar remote sensing and sample
acquisition techniques and provide a sustainable way of monitoring processes in
key locations on planetary surfaces while maintaining a low environmental
footprint. These tools, which we call Biscuits, can use customized materials as
wide ranging as zircon-based spray coatings to metals potentially usable for
surface structures, to target specific processes/questions as part of a small,
passive witness plate that can be flexibly placed with respect to location and
total time duration. We examine and discuss unique case studies to show how
processes such as water presence/transport, presence and contamination of
biologically relevant molecules, solar activity related effects, and other
processes can be measured using Biscuits. Biscuits can yield key location
sensitive, time integrated measurements on these processes to inform scientific
understanding of the Moon and enable operational goals in lunar exploration.
While we specifically demonstrate this on a simulated traverse and for selected
examples, we stress all groups interested in planetary surfaces should consider
these adaptable, low footprint and highly informative tools for future
exploration.Comment: Accepted to Earth and Space Science, Will be updated upon publicatio
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