Superparamagnetic relaxation in Cu_{x}Fe_{3-x}O_{4} (x=0.5 and x=1) nanoparticles

The scope of this article is to report very detailed results of the measurements of magnetic relaxation phenomena in the new Cu$_{0.5}$Fe$_{2.5}$O$_{4}$ nanoparticles and known CuFe$_{2}$O$_{4}$ nanoparticles. The size of synthesized particles is (6.5$\pm$1.5)nm. Both samples show the superparamagnetic behaviour, with the well-defined phenomena of blocking of magnetic moment. This includes the splitting of zero-field-cooled and field-cooled magnetic moment curves, dynamical hysteresis, slow quasi-logarithmic relaxation of magnetic moment below blocking temperature. The scaling of the magnetic moment relaxation data at different temperatures confirms the applicability of the simple thermal relaxation model. The two copper-ferrites with similar structures show significantly different magnetic anisotropy density and other magnetic properties. Investigated systems exhibit the consistency of all obtained results.Comment: 18 pages, 8 figure

Mast cells are key mediators of cathelicidin-initiated skin inflammation in rosacea.

Rosacea is a chronic inflammatory skin disease whose pathophysiological mechanism is still unclear. However, it is known that mast cell (MC) numbers are increased in the dermis of rosacea patients. MC proteases not only recruit other immune cells, which amplify the inflammatory response, but also cause vasodilation and angiogenesis. MCs are also one of the primary sources of cathelicidin LL-37 (Cath LL-37), an antimicrobial peptide that has been shown to be an enabler of rosacea pathogenesis. Here, we demonstrate that MCs are key mediators of cathelicidin-initiated skin inflammation. After Cath LL-37 injection into the dermis, MC-deficient B6.Cg-Kit(W-sh)/HNihrJaeBsmJ (KitW-sh) mice did not develop rosacea-like features. Conversely, chymase (P<0.001), tryptase, and Mmp9 (P<0.01) mRNA levels were significantly higher in C57BL/6 wild-type (WT) mice. Treating WT mice with an MC stabilizer significantly decreased the expressions of Mmp9 and Cxcl2 (P<0.01). Our data were confirmed on erythematotelangiectatic rosacea subjects who showed a decrease in matrix metalloproteinase activity (P<0.05), after 8 weeks of topical cromolyn treatment. We conclude that MCs have a central role in the development of inflammation subsequent to Cath LL-37 activation and that downregulation of activated MCs may be a therapy for rosacea treatment

Combination of Biomarkers:PET [¹⁸F]Flutemetamol Imaging and Structural MRI in Dementia and Mild Cognitive Impairment

&lt;i&gt;Background:&lt;/i&gt;The New National Institute on Aging-Alzheimer’s Association diagnostic guidelines for Alzheimer’s disease (AD) incorporate biomarkers in the diagnostic criteria and suggest division of biomarkers into two categories: Aβ accumulation and neuronal degeneration or injury. &lt;i&gt;Objective:&lt;/i&gt;It was the aim of this study to compute hippocampus volume from MRI and a neocortical standard uptake value ratio (SUVR) from [&lt;sup&gt;18&lt;/sup&gt;F]flutemetamol PET and investigate the performance of these biomarkers when used individually and when combined. &lt;i&gt;Methods:&lt;/i&gt; Fully automated methods for hippocampus segmentation and for computation of neocortical SUVR were applied to MR and scans with the investigational imaging agent [&lt;sup&gt;18&lt;/sup&gt;F]flutemetamol in a cohort comprising 27 AD patients, 25 healthy volunteers (HVs) and 20 subjects with amnestic mild cognitive impairment (MCI). Clinical follow-up was performed 2 years after the initial assessment. &lt;i&gt;Results:&lt;/i&gt;Hippocampus volumes showed extensive overlap between AD and HV cases while PET SUVRs showed clear group clustering. When both measures were combined, there was a relatively compact cluster of HV scans and a less compact AD cluster. MCI cases had a bimodal distribution of SUVRs. [&lt;sup&gt;18&lt;/sup&gt;F]Flutemetamol-positive MCI subjects showed a large variability in hippocampus volumes, indicating that these subjects were in different stages of neurodegeneration. Some [&lt;sup&gt;18&lt;/sup&gt;F]flutemetamol-negative MCI scans had hippocampus volumes that were well below the HV range. Clinical follow-up showed that 8 of 9 MCI to AD converters came from the [&lt;sup&gt;18&lt;/sup&gt;F]flutemetamol-positive group. &lt;i&gt;Conclusion:&lt;/i&gt;Combining [&lt;sup&gt;18&lt;/sup&gt;F]flutemetamol PET with structural MRI provides additional information for categorizing disease and potentially predicting shorter time to progression from MCI to AD, but this has to be validated in larger longitudinal studies.</jats:p