562 research outputs found
Ecdysteroids: A novel class of anabolic agents?
Increasing numbers of dietary supplements with ecdysteroids are marketed as “natural anabolic agents”. Results of recent studies suggested that their anabolic effect is mediated by estrogen receptor (ER) binding. Within this study the anabolic potency of ecdysterone was compared to well characterized anabolic substances. Effects on the fiber sizes of the soleus muscle in rats as well the diameter of C2C12 derived myotubes were used as biological readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size of rat soleus muscle that was found even stronger compared to the test compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1, all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12 myotubes ecdysterone (1 µM) induced a significant increase of the diameter comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking experiments supported the ERβ mediated action of ecdysterone. To clarify its status in sports, ecdysterone should be considered to be included in the class “S1.2 Other Anabolic Agents” of the list of prohibited substances of the World Anti-Doping Agency
Is machine learning prediction of Aβ positivity consistent? An assessment of multiple datasets
Poster abstrac
A novel class of anabolic agents?
Increasing numbers of dietary supplements with ecdysteroids are marketed as
“natural anabolic agents”. Results of recent studies suggested that their
anabolic effect is mediated by estrogen receptor (ER) binding. Within this
study the anabolic potency of ecdysterone was compared to well characterized
anabolic substances. Effects on the fiber sizes of the soleus muscle in rats
as well the diameter of C2C12 derived myotubes were used as biological
readouts. Ecdysterone exhibited a strong hypertrophic effect on the fiber size
of rat soleus muscle that was found even stronger compared to the test
compounds metandienone (dianabol), estradienedione (trenbolox), and SARM S 1,
all administered in the same dose (5 mg/kg body weight, for 21 days). In C2C12
myotubes ecdysterone (1 µM) induced a significant increase of the diameter
comparable to dihydrotestosterone (1 µM) and IGF 1 (1.3 nM). Molecular docking
experiments supported the ERβ mediated action of ecdysterone. To clarify its
status in sports, ecdysterone should be considered to be included in the class
“S1.2 Other Anabolic Agents” of the list of prohibited substances of the World
Anti-Doping Agency
A theoretical study of the C- 4So_3/2 and 2Do_{3/2,5/2} bound states and C ground configuration: fine and hyperfine structures, isotope shifts and transition probabilities
This work is an ab initio study of the 2p3 4So_3/2, and 2Do_{3/2,5/2} states
of C- and 2p2 3P_{0,1,2}, 1D_2, and 1S_0 states of neutral carbon. We use the
multi-configuration Hartree-Fock approach, focusing on the accuracy of the wave
function itself. We obtain all C- detachment thresholds, including correlation
effects to about 0.5%. Isotope shifts and hyperfine structures are calculated.
The achieved accuracy of the latter is of the order of 0.1 MHz.
Intra-configuration transition probabilities are also estimated.Comment: 15 pages, 2 figures, 12 table
Direct visualisation of collateral ventilation in COPD with hyperpolarised gas MRI
Abstract
Background Collateral ventilation has been proposed as a mechanism of compensation of respiratory function in obstructive lung diseases but observations of it in vivo are limited. The assessment of collateral ventilation with an imaging technique might help to gain insight into lung physiology and assist the planning of new bronchoscopic techniques for treating emphysema.
Objective
To obtain images of delayed ventilation that might be related to collateral ventilation over the period of a single breath-hold in patients with chronic obstructive pulmonary disease (COPD).
Methods
Time-resolved breath-hold hyperpolarised 3He MRI was used to obtain images of the progressive influx of polarised gas into initially non-ventilated defects.
Results
A time-series of images showed that 3He moves into lung regions which were initially non-ventilated. Ventilation defects with delayed filling were observed in 8 of the 10 patients scanned.
Conclusions
A method for direct imaging of delayed ventilation within a single breath-hold has been demonstrated in patients with COPD. Images of what is believed to be collateral ventilation and slow filling of peripheral airspaces due to increased flow resistance are presented. The technique provides 3D whole-lung coverage with sensitivity to regional information, and is non-invasive and non-ionising
Effects of erythropoietin in murine-induced pluripotent cell-derived panneural progenitor cells
Induced cell fate changes by reprogramming of somatic cells offers an efficient strategy to generate autologous pluripotent stem (iPS) cells from any adult cell type. The potential of iPS cells to differentiate into various cell types is well established, however the efficiency to produce functional neurons from iPS cells remains modest. Here, we generated panneural progenitor cells (pNPCs) from mouse iPS cells and investigated the effect of the neurotrophic growth factor erythropoietin (EPO) on their survival, proliferation and neurodifferentiation. Under neural differentiation conditions, iPS-derived pNPCs gave rise to microtubule-associated protein-2 positive neuronlike cells (34% to 43%) and platelet-derived growth factor receptor positive oligodendrocytelike cells (21% to 25%) while less than 1% of the cells expressed the astrocytic marker glial fibrillary acidic protein. Neuronlike cells generated action potentials and developed active presynaptic terminals. The pNPCs expressed EPO receptor (EPOR) mRNA and displayed functional EPOR signaling. In proliferating cultures, EPO (0.1–3 U/mL) slightly improved pNPC survival but reduced cell proliferation and neurosphere formation in a concentration-dependent manner. In differentiating cultures EPO facilitated neurodifferentiation as assessed by the increased number of β-III-tubulin positive neurons. Our results show that EPO inhibits iPS pNPC self-renewal and promotes neurogenesis
Förster Resonance Energy Transfer (FRET) Correlates of Altered Subunit Stoichiometry in Cys-Loop Receptors, Exemplified by Nicotinic α4β2
We provide a theory for employing Förster resonance energy transfer (FRET)
measurements to determine altered heteropentameric ion channel stoichiometries in
intracellular compartments of living cells. We simulate FRET within nicotinic receptors
(nAChRs) whose α4 and β2 subunits contain acceptor and donor fluorescent protein
moieties, respectively, within the cytoplasmic loops. We predict FRET and normalized
FRET (NFRET) for the two predominant stoichiometries, (α4)3(β2)2 vs. (α4)2(β2)3.
Studying the ratio between FRET or NFRET for the two stoichiometries, minimizes
distortions due to various photophysical uncertainties. Within a range of assumptions
concerning the distance between fluorophores, deviations from plane pentameric geometry,
and other asymmetries, the predicted FRET and NFRET for (α4)3(β2)2 exceeds that of
(α4)2(β2)3. The simulations account for published data on transfected Neuro2a cells in
which α4β2 stoichiometries were manipulated by varying fluorescent subunit cDNA ratios:
NFRET decreased monotonically from (α4)3(β2)2 stoichiometry to mostly (α4)2(β2)3. The
simulations also account for previous macroscopic and single-channel observations that
pharmacological chaperoning by nicotine and cytisine increase the (α4)2(β2)3 and
(α4)3(β2)2 populations, respectively. We also analyze sources of variability. NFRET-based monitoring of changes in subunit stoichiometry can contribute usefully to studies on
Cys-loop receptors
Virtual screening and evaluation of Ketol-Acid Reducto-Isomerase (KARI) as a putative drug target for Aspergillosis
Aspergillus is a leading causative agent for fungal morbidity and mortality in immuno-compromised patients. To identify a putative target to design or identify new antifungal drug, against Aspergillus is required. In our previous work, we have analyzed the various biochemical pathways, and we found Ketol Acid Reducto-Isomerase (KARI) an enzyme involves in the amino acid biosynthesis, could be a better target. This enzyme was found to be unique by comparing to host proteome through BLASTp analysis. A homology based model of KARI was generated by Swiss model server. The generated model had been validated by PROCHECK and WHAT IF programs. The Zinc library was generated within the limitation of the Lipinski rule of five, for docking study. Based on the dock-score six molecules have been studied for ADME/TOX analysis and subjected for pharmacophore model generation. The Zinc ID of the potential inhibitors is ZINC00720614, ZINC01068126, ZINC0923, ZINC02090678, ZINC00663057 and ZINC02284065 and found to be pharmacologically active agonist and antagonist of KARI. This study is an attempt to Insilco evaluation of the KARI as a drug target and the screened inhibitors could help in the development of the better drug against Aspergillus
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