Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.     

Nonsalt 1‐(arylmethyloxy)pyrene photoinitiators capable of initiating cationic polymerization

Analysis of photoproducts derived from 1‐(methoxynaphthalen‐1‐ylmethyloxy)pyrene initiators and polymer end groups demonstrated that methoxynaphthalen‐1‐ylmethyl carbocation is involved in the initiation steps for both styrene (St) and cyclohexene oxide (CHO) polymerization. Charge transfer from the pyrenyloxy oxygen atom to the methoxynaphthalen‐1‐ylmethyl chromophore in the singlet excited state is assumed to be responsible for the efficient generation of the carbocation species, which also initiates the copolymerization of St and CHO. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40510.     

Effect of Platelet-Rich Plasma on M1/M2 Macrophage Polarization

Osteoarthritis of the knee (OAK) is a chronic degenerative disease and progresses with an imbalance of cytokines and macrophages in the joint. Studies regarding the use of platelet-rich plasma (PRP) as a point-of-care treatment for OAK have reported on its effect on tissue repair and suppression of inflammation but few have reported on its effect on macrophages and macrophage polarization. Based on our clinical experience with two types of PRP kits Cellaid Serum Collection Set P type kit (leukocyte-poor-PRP) and an Autologous Protein Solution kit (APS leukocyte-rich-PRP), we investigated the concentrations of humoral factors in PRPs prepared from the two kits and the effect of humoral factors on macrophage phenotypes. We found that the concentrations of cell components and humoral factors differed between PRPs purified using the two kits; APS had a higher concentration of M1 and M2 macrophage related factors. The addition of PRP supernatants to the culture media of monocyte-derived macrophages and M1 polarized macrophages revealed that PRPs suppressed M1 macrophage polarization and promoted M2 macrophage polarization. This research is the first to report the effect of PRPs purified using commercial kits on macrophage polarization.     

Molecular Design and Synthesis of a Novel Substrate for Assaying Lysozyme Activity

A novel substrate {Galβ1,4GlcNAcβ1,4GlcNAc-β-pNP [Gal(GlcNAc)₂-β-pNP]} for assaying lysozyme activity has been designed using docking simulations and enzymatic synthesis via β-1,4-galactosyltransferase-mediated transglycosylation from UDP-Gal as the donor to (GlcNAc)₂-β-pNP as the acceptor. Hydrolysis of the synthesized Gal(GlcNAc)₂-β-pNP and related compounds using hen egg-white lysozyme (HEWL) demonstrated that the substrate was specifically cleaved to Gal(GlcNAc)₂ and p-nitrophenol (pNP). A combination of kinetic studies and docking simulation was further conducted to elucidate the mode of substrate binding. The results demonstrate that Gal(GlcNAc)₂-β-pNP selectively binds to a subsite of lysozyme to liberate the Gal(GlcNAc)₂ and pNP products. The work therefore describes a new colorimetric method for quantifying lysozyme on the basis of the determination of pNP liberated from the substrate.     

Bioconversion of 1-adamantanol to 1,3-adamantanediol using Streptomyces sp. SA8 oxidation system

To efficiently produce 1,3-adamantanediol (1,3-ad(OH)₂) from 1-adamantanol (1-adOH), our stocks of culture strains and soil microorganisms were surveyed for hydroxylation activity towards 1-adOH. Among them, the soil actinomycete SA8 showing the highest hydroxylation activity was identified as Streptomyces sp. based on 16S ribosomal DNA sequence analysis. The reaction products were purified by silica gel column chromatography, and from NMR and MS analyses, they were identified as 1,3-ad(OH)₂ and 1,4-ad(OH)₂. Streptomyces sp. SA8 produced 5.9 g l^? 1 1,3-ad(OH)₂from 6.2 g l^? 1 1-adOH in culture broth after 120 h at 25 °C. Using resting cells, 2.3 g l^? 1 1,3-ad(OH)₂ was produced after 96 h of incubation at a 69% conversion rate. In both cases, 1,4-ad(OH)₂ was formed as a byproduct at a rate of about 15%. Strain SA8 also hydroxylated 2-adamantanol and 2-methyl-2-adamantanol.     

Synergistic effect of Pt or Pd and perovskite oxide for water gas shift reaction

The water gas shift (WGS) reaction over Pt and Pd catalysts supported on various perovskite oxides has been investigated at 573 K without catalyst pretreatment. The Pt and Pd catalysts on LaCoO₃ support showed high catalytic activity. Interaction between Pt or Pd and the support is considered to promote the WGS reaction: Pt/LaCoO₃ had high initial activity but deactivated immediately; Pd/LaCoO₃ was less active than Pt/LaCoO₃, but had superior stability. Catalysts were characterized using XRD, STEM, XPS, and H₂-temperature programmed reduction (TPR). Results of this study showed that reduction of the support decreased the CO conversion on Pt/LaCoO₃. On the other hand, Pd/LaCoO₃ showed stable activity for the WGS reaction. Therefore, Pd was added to Pt/LaCoO₃ for stabilizing the catalyst activity, and 0.5 wt.% Pd/1 wt.% Pt/LaCoO₃ catalyst showed higher activity and stability.     

Synthesis and photophysical properties of structural isomers of novel 2,10-disubstituted benzofuro[2,3-e]naphthoxazole-type fluorescent dyes

Structural isomers of novel 2,10-disubstituted benzofuro[2,3-e]naphthoxazole fluorescent dyes have been synthesized. The phtophysical properties have been investigated in solution and in the solid state. The absorption and fluorescence intensities of the naphth[1,2-d]oxazoles are much stronger than those of the naphth[2,1-d]oxazoles in solution. Moreover, in the solid state, the emission intensities of the former are typically much stronger than those of latter isomers. To understand the differences in photophysical properties, semi-empirical molecular orbital calculations and the X-ray crystallographic analyses have been performed.     

Dietary mercury has no observable effects on thyroid-mediated processes and fitness-related traits in wood frogs

Mercury (Hg) is a neurotoxicant known to cause developmental and behavioral abnormalities in vertebrates. Increasing evidence suggests that Hg can also disrupt endocrine functions and endocrine-dependent processes. For example, dietary Hg has been shown to delay tail resorption during metamorphic climax in amphibians, a process mediated by thyroid hormones. However, a direct link between Hg, hormone disruption, and developmental delays in amphibians has not been explored. Therefore, we examined the effects of dietary Hg (0.01, 2.5, and 10 μg/g total Hg, dry wt) on thyroid hormone concentrations, development, growth, performance, and survival of wood frogs (Rana sylvatica). Tadpoles accumulated Hg in a concentration-dependent manner; total Hg concentrations in tadpoles at the beginning of metamorphic climax (Gosner stage 42) were 0.03, 1.06, 3.54 μg/g, dry wt, for control, low, and high Hg diets, respectively. During metamorphic climax, tadpoles eliminated 35% of the inorganic Hg from their tissues but retained most of their accumulated methylmercury. Contrary to our predictions, we found no effect of Hg on the duration of tadpole development, size at metamorphosis, tail resorption time, or hopping performance. Consistent with the lack of effects on development, we also detected no differences in whole-body thyroid hormone concentrations among our dietary treatments. Our results, when compared with the effects of Hg on other amphibians, suggest that amphibian species may differ substantially in their sensitivity to dietary Hg, emphasizing the need for data on multiple species when establishing toxicity benchmarks.