The effects of five UICC asbestos samples, titanium dioxide, and quartz on the bovine red cell membrane have been studied in erythrocyte ghosts by the spin labelling technique. Analysis of the electron paramagnetic resonance (EPR) spectra of two sulphydryl reactive spin labels and one fatty acid spin label in red cell ghosts showed modifications in membrane protein after asbestos treatment but no alterations in membrane lipids. In experiments with quartz no membrane changes were noted but titanium dioxide altered the proteins bound with the protein reactive spin label used in the present study. The possible mechanism for these effects is discussed.
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http://dx.doi.org/10.1136/oem.42.4.281 | DOI Listing |
J Org Chem
January 2025
Faculty of Chemistry and Center for Molecular Materials (CM2), Bielefeld University, Universitätsstraße 25, Bielefeld 33615, Germany.
Spin labels based on Gd complexes are important tools for the elucidation of the structure, dynamics and interaction of biomolecules by electron paramagnetic resonance (EPR) spectroscopy. Their EPR spectroscopic properties line width and relaxation times influence their performance in a particular application. To be able to apply a complex well-suited for a specific application, a set of Gd complexes with different EPR spectroscopic properties ready-made for spin labeling will be highly useful.
View Article and Find Full Text PDFNMR Biomed
March 2025
Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
Hemodynamic measurements such as cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) can provide useful information for the diagnosis and characterization of brain tumors. Previous work showed that arterial spin labeling (ASL) in combination with vasoactive stimulation enabled simultaneous non-invasive evaluation of both parameters, however this approach had not been previously tested in tumors. The aim of this work was to investigate the application of this technique, using a pseudo-continuous ASL (PCASL) sequence combined with breath-holding at 3 T, to measure CBF and CVR in high-grade gliomas and metastatic lesions, and to explore differences across tumoral-peritumoral regions and tumor types.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir Prelog Weg 2, 8093 Zurich, Switzerland.
Relaxation-induced dipolar modulation enhancement (RIDME) is a pulse EPR experiment originally designed to determine distances between spin labels. However, RIDME has several features that make it an efficient tool in a number of "nonconventional" applications, away from the original purpose of this pulse experiment. RIDME appears to be an interesting experiment to probe longitudinal electron spin dynamics, e.
View Article and Find Full Text PDFChemphyschem
January 2025
Deutsches Krebsforschungszentrum, Translational Molecular Imaging, Im Neuenheimer Feld 223, 69120, Heidelberg, GERMANY.
Chemical exchange saturation transfer (CEST) improves the sensitivity of NMR but depending on the spin exchange kinetics, it can require substantial RF energy deposition to label magnetization. Potential side effects like RF-induced heating may occur and must be monitored. Here, we explore the parameter space considering not only undesired heating but efficient CEST build-up (depolarization rate), spectral resolution (line width), and subsequent effects like changes in chemical shifts of CEST responses must be considered, too.
View Article and Find Full Text PDFHum Brain Mapp
February 2025
Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea.
Magnetic susceptibility source separation (χ-separation), an advanced quantitative susceptibility mapping (QSM) method, enables the separate estimation of paramagnetic and diamagnetic susceptibility source distributions in the brain. Similar to QSM, it requires solving the ill-conditioned problem of dipole inversion, suffering from so-called streaking artifacts. Additionally, the method utilizes reversible transverse relaxation ( ) to complement frequency shift information for estimating susceptibility source concentrations, requiring time-consuming data acquisition for (e.
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