Controlled structure and properties of silicate nanoparticle networks for incorporation of biosystem components

Inorganic nanoparticles are of technological interest in many fields. We created silicate nanoparticle hydrogels that effectively incorporated biomolecules that are unstable and involved in complicated reactions. The size of the silicate nanoparticles strongly affected both the physical characteristics of the resulting hydrogel and the activity of biomolecules incorporated within the hydrogel. We used high-resolution transmission electron microscopy (TEM) to analyze in detail the hydrogel network patterns formed by the silicate nanoparticles. We obtained clear nanostructured images of biomolecule-nanoparticle composite hydrogels. The TEM images also showed that larger silicate nanoparticles (22 nm) formed more loosely associated silicate networks than did smaller silicate nanoparticles (7 nm). The loosely associated networks formed from larger silicate nanoparticles might facilitate substrate diffusion through the network, thus promoting the observed increased activity of the entrapped biomolecules. This doubled the activity of the incorporated biosystems compared with that of biosystems prepared by our own previously reported method. We propose a reaction scheme to explain the formation of the silicate nanoparticle networks. The successful incorporation of biomolecules into the nanoparticle hydrogels, along with the high level of activity exhibited by the biomolecules required for complicated reaction within the gels, demonstrates the nanocomposites' potential for use in medical applications.     

Comparison of sulfuric acid treatment and multi-layer silica gel column chromatography in cleanup methods for determination of PCDDs,PCDFs and dioxin-like PCBs in foods

Two typical cleanup methods, sulfuric acid treatment and multi-layer silica gel column chromatography, for the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in seventeen food samples were examined and compared. Vegetables, fruits, cereals, fish, meat and dairy foods were extracted by conventional methods (shaking with acetone/n-hexane or with n-hexane after alkaline treatment). The extracts were cleaned up by sulfuric acid treatment or multi-layer silica gel column chromatography, followed by several column chromatographic steps. Of the samples treated, the vegetable, fruit and cereal samples could be directly applied to the multi-layer silica gel column after extraction. However, the samples containing fats and oils such as fish, meat and dairy foods needed to be treated several times with concentrated sulfuric acid before multi-layer column chromatography, because these samples plugged the column with oily residues. Both cleanup methods gave similar values of isomeric concentrations and showed similar efficiency of purification, and the recoveries ranged from 40 to 120%. These results are considered to provide useful data for the efficient analysis of dioxins in foods which have wide-ranging compositions.     

Construction of novel vectors for transformation of Lentinula edodes using a chitin synthase gene promoter

Novel vectors (pLCHS-hph and pChG-bar) containing expression unit driving hph as a selectable marker gene by chitin synthase gene promoter were constructed for Lentinula edodes transformation. Expression of the hph gene in random selected transformants was confirmed by RT-PCR method. Thus, both vectors are useful for L. edodes transformation.     

Electrical and magnetic properties of electro-oxidative polymerized poly(tris(thienylphenyl)amine)s

Electro-oxidative polymerized poly(tris(thienylphenyl)amine)s, which have the hyperbranched (dendritic) structure (PTPA) and linear type (PMeTPA), were investigated for their electrical and magnetic properties. The conductivity PTPA showed was almost one order higher than that of PMeTPA. From the solid state ESR measurements of the polymers, observation of ESR signal at g = 2.0027 and 2.0030 indicated the formation of a triphenylamine cation radical. The normalized magnetization plots (M/M_s) for PTPA and PMeTPA are close to the theoretical Brillouin curves for S = 1, indicating a magnetic interaction between the spin centers in PMeTPA. The spin concentrations determined by the M_s values of PTPA and PMeTPA were 7.3–7.4 and 1.3–1.4%, respectively. This large difference in the spin concentration of the polymers according to the structure resulted from a different spin conformation by the radical structure.     

Flame retardancy and thermomechanical properties of the poly‐(glycidyloxypropyl) phenyl silsesquioxane/layered titanate nanocomposites

Poly‐(glycidyloxypropyl) phenyl silsesquioxane (PGPSQ) was combined with an organo‐layered titanate filler. The phase structure of the obtained composite was evaluated by XRD and TEM observations. Moreover, a burning test was carried out according to the UL‐94 test method. The extinguishing time of the nanocomposites was classified V‐0 even for the 1 wt % layered titanate content. Based on the results, it was clarified that the frame retardancy of the PGPSQ/organo‐layered titanate system was superior to the poly‐(glycidyloxypropyl) silsesquioxane (PGSQ)/organo‐layered titanate system, which was reported in a previous paper. In addition, the layered titanate as a filler also improved the ductility of the PGPSQ. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Idiopathic Plasmacytic Lymphadenopathy Forms an Independent Subtype of Idiopathic Multicentric Castleman Disease

Idiopathic multicentric Castleman disease (iMCD) is a type of Castleman disease that is not related to KSHV/HHV8 infection. Currently, iMCD is classified into iMCD-TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) and iMCD-NOS (not otherwise specified). The former has been established as a relatively homogeneous disease unit that has been recently re-defined, while the latter is considered to be a heterogeneous disease that could be further divided into several subtypes. In 1980, Mori et al. proposed the concept of idiopathic plasmacytic lymphadenopathy (IPL), a disease presenting with polyclonal hypergammaglobulinemia and a sheet-like proliferation of mature plasma cells in the lymph nodes. Some researchers consider IPL to be a part of iMCD-NOS, although it has not been clearly defined to date. This is the first paper to analyze iMCD-NOS clinicopathologically, to examine whether IPL forms a uniform disease unit in iMCD. Histologically, the IPL group showed prominent plasmacytosis and the hyperplasia of germinal centers, while the non-IPL group showed prominent vascularity. Clinically, the IPL group showed significant thrombocytosis and elevated serum IgG levels compared to the non-IPL group (p = 0.007, p < 0.001, respectively). Pleural effusion and ascites were less common in the IPL group (p < 0.001). The IPL group was more likely to have an indolent clinical course and a good response to the anti-IL-6 receptor antibody, while the non-IPL counterpart frequently required more aggressive medical interventions. Thus, the IPL group is a clinicopathologically uniform entity that forms an independent subtype of iMCD.     

Spatial and Quantitative Analysis of Tumor-Associated Macrophages: Intratumoral CD163-/PD-L1+ TAMs as a Marker of Favorable Clinical Outcomes in Triple-Negative Breast Cancer

Tumor-associated macrophages (TAMs) and abnormalities in cancer cells affect cancer progression and response to therapy. TAMs are a major component of the tumor microenvironment (TME) in breast cancer, with their invasion affecting clinical outcomes. Programmed death-ligand 1 (PD-L1), a target of immune checkpoint inhibitors, acts as a suppressive signal for the surrounding immune system; however, its expression and effect on TAMs and the clinical outcome in breast cancer are unknown. In this study, we used high-throughput multiple immunohistochemistry to spatially and quantitatively analyze TAMs. We subjected 81 breast cancer specimens to immunostaining for CD68, CD163, PD-1, PD-L1, CD20, and pan-CK. In both stromal and intratumoral areas, the triple-negative subtype had significantly more CD68/CD163, CD68/PD-L1, and CD163/PD-L1 double-positive cells than the estrogen receptor (ER)/progesterone receptor (PR) subtype. Interestingly, a higher number of CD68+/PD-L1+/CK-/CD163- TAMs in the intratumoral area was correlated with a favorable recurrence rate (p = 0.048). These findings indicated that the specific subpopulation and localization of TAMs in the TME affect clinical outcomes in breast cancer.     

Role of boric acid in the formation of poly(vinyl alcohol)-iodine complexes in undrawn films

The role of boric acid in the formation of poly(vinyl alcohol) (PVA)-iodine complexes in undrawn films has been investigated by using wide-angle X-ray diffraction (WAXD) and high-resolution solid-state ¹³C NMR spectroscopy. From UV-vis absorption spectroscopy, it is confirmed that boric acid is necessary for the formation of the complexes in films that are treated with I₂/KI aqueous solutions at relatively low I₂ concentrations. The WAXD profiles indicate that, irrespective of the presence of iodine, crystallite sizes perpendicular to the chain axis become smaller by the addition of boric acid in the swelling media. Moreover, small crystallites and surficial parts of larger crystallites may be partially dissolved in the swelling process with water and boric acid suppresses the re-crystallization in the drying process with or without iodine. The ¹³C spin-lattice relaxation time analysis reveals that there exist two components called the mobile and the less mobile components in the films and the latter component, which contains the complexes and the crystalline component, is increased in the fraction by the presence of boric acid. The evaluation of the CH resonance line shows that some of the intermolecular hydrogen bonds are broken by boric acid, which increases the intramolecular hydrogen bonds. The CH₂ lineshape analysis also reveals that the gauche fraction is appreciably increased in the less mobile component by the addition of boric acid. These facts suggest that boric acid may promote the formation of PVA-iodine complexes particularly in the surficial areas of the crystallites probably by reducing the molecular mobility of the PVA chains by causing cross-linking among them.     

Improved Methods for the Fatty Acid Analysis of Blood Lipid Classes

Two improved methods have been developed for preparation of fatty acid methyl esters (FAME) from major O-ester lipid classes in blood, i.e., cholesterol ester, triacylglycerol, and glycerophospholipids. The methods involve simple operations, and use neither harmful solvents such as chloroform or benzene nor highly reactive volatile reagents such as acetyl chloride. The FAME synthesis reaction proceeds under mild temperature conditions. The methods include (1) extraction of lipids from 0.2 ml of blood with 0.2 ml of tert-butyl methyl ether and 0.1 ml of methanol, (2) separation of the total lipids into lipid classes using a solid-phase extraction column or thin-layer chromatography, and (3) methanolysis of each lipid class at room temperature or at 45 °C. In all the operations, solvent concentration is performed only once prior to gas–liquid chromatography (GC). No noticeable differences in composition determined by GC have been found between FAME prepared by the present methods and those prepared by a conventional method involving lipid extraction with chloroform/methanol. The mild reaction and simplified procedures of the present methods enabled safe and reproducible analysis of the fatty acid compositions of the major ester-lipid classes in blood.