4,097 research outputs found
Laser Doppler scanning study of palmar skin perfusion for patients with hyperhidrosis before and after thoracic sympathectomy.
No full text
Imaging of skin dermal thermal damage by multiphoton autofluroescence and second harmonic generation (SHG) microscopy
No full textWellesly Sh. W. to Mr. James Meredith (2 October 1962)
Full text linkSigned by Wellesly Sh. W.https://egrove.olemiss.edu/mercorr_pro/1531/thumbnail.jp
A cell line that secretes inducibly a reporter protein for monitoring herpes simplex virus infection and drug susceptibility
No full textTransmission of occult hepatitis B virus by transfusion to adult and pediatric recipients in Taiwan
No full textSMA-SH: Modified styrene maleic acid copolymer for functionalization of lipid nanodiscs
No full textChallenges in purification and subsequent functionalization of membrane proteins often complicate their biochemical and biophysical characterization. Purification of membrane proteins generally involves replacing the lipids surrounding the protein with detergent molecules, which can affect protein structure and function. Recently, it was shown that styrene–maleic acid copolymers (SMA) can dissolve integral membrane proteins from biological membranes into nanosized discs. Within these nanoparticles, proteins are embedded in a patch of their native lipid bilayer that is stabilized in solution by the amphipathic polymer that wraps the disc like a bracelet. This approach for detergent-free purification of membrane proteins has the potential to greatly simplify purification but does not facilitate conjugation of functional compounds to the membrane proteins. Often, such functionalization involves laborious preparation of protein variants and optimization of labeling procedures to ensure only minimal perturbation of the protein. Here, we present a strategy that circumvents several of these complications through modifying SMA by grafting the polymer with cysteamine. The reaction results in SMA that has solvent-exposed sulfhydrils (SMA-SH) and allows tuning of the coverage with SH groups. Size exclusion chromatography, dynamic light scattering, and transmission electron microscopy demonstrate that SMA-SH dissolves lipid bilayer membranes into lipid nanodiscs, just like SMA. In addition, we demonstrate that, just like SMA, SMA-SH solubilizes proteoliposomes into protein-loaded nanodiscs. We covalently modify SMA-SH-lipid nanodiscs using thiol-reactive derivatives of Alexa Fluor 488 and biotin. Thus, SMA-SH promises to simultaneously tackle challenges in purification and functionalization of membrane proteins.BN/Marie-Eve Aubin-Tam LabBN/Andreas Engel La
Omega-3 fatty acid eicospentaenoic acid attenuates MPP+-induced neurodegeneration in fully differentiated human SH- SY5Y and primary mesencephalic cells
No full textEicosapentaenoic acid ( EPA), a neuroactive omega-3 fatty acid, has been demonstrated to exert neuroprotective effects in experimental models of Parkinson's disease ( PD), but the cellular mechanisms of protection are unknown. Here, we studied the effects of EPA in fully differentiated human SH-SY5Y cells and primary mesencephalic neurons treated with MPP+. In both in-vitro models of PD, EPA attenuated an MPP+-induced reduction in cell viability. EPA also prevented the presence of electron-dense cytoplasmic inclusions in SH-SY5Y cells. Then, possible mechanisms of the neuroprotection were studied. In primary neurons, EPA attenuated an MPP+-induced increase in Tyrosine-related kinase B (TrkB) receptors. In SH-SY5Y cells, EPA down-regulated reactive oxygen species and nitric oxide. This antioxidant effect of EPA may have been mediated by its inhibition of neuronal NADPH oxidase and cyclo-oxygenase-2 ( COX-2), as MPP+ increased the expression of these enzymes. Furthermore, EPA prevented an increase in cytosolic phospholipase A2 ( cPLA2), an enzyme linked with COX-2 in the potentially pro-inflammatory arachidonic acid cascade. Lastly, EPA attenuated an increase in the bax:bcl-2 ratio, and cytochrome c release. However, EPA did not prevent mitochondrial enlargement or a decrease in mitochondrial membrane potential. This study demonstrated cellular mechanisms by which EPA provided neuroprotective effects in experimental P
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