Synthesis and characterization of chitosan/poly(acrylic acid) polyelectrolyte complex

Polyelectrolyte complex based on chitosan and acrylic acid monomer by photoinitiated free‐radical polymerization in the absence of crosslinker showed a large transition in swelling in response to changes in pH of surrounding medium. Their ability to swell arises from polyelectrolyte interactions and molecular structure of the complex. The main properties of interest that related to the molecular structure, swelling volumes, glass transition temperature, and elastic modulus of the complex were investigated. The effect of water content, the only variable in the sample component, played an important role in molecular structure of the complex and as a consequence, the extent of intermolecular linkage, especially amide bonds which in turn governed the degree of swelling of the polyelectrolyte complex in this study. The decreased degree of swelling and higher temperature shift of glass transition temperature was found with increased water content, whereas increased modulus of elasticity of dry complex was found in lower water content of synthesis component. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1025–1035, 2002     

Novel sulfated oligosaccharides containing 3-O-sulfated glucuronic acid from king crab cartilage chondroitin sulfate K. Unexpected degradation by chondroitinase ABC

We prepared a series of oligosaccharides from king crab cartilage chondroitin sulfate K after exhaustive digestion with testicular hyaluronidase, and determined the structures of four tetrasaccharides and a pentasaccharide by fast atom bombardment mass spectrometry, high performance liquid chromatography analysis of chondroitinase AC-II digests, and 500-MHz 1H NMR spectroscopy. The tetrasaccharides shared the common core structure GlcAbeta1-3GalNAcbeta1-4GlcAbeta1-3GalNAc with various sulfation profiles. One structure was GlcAbeta1-3GalNAc(4S)beta1-4GlcAbeta1-3GalNAc(4S), whereas three of them have the following hitherto unreported structures including a novel glucuronate 3-O-sulfate: GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcAbeta1-3GalNAc(4S), GlcAbeta1-3GalNAc(4S)beta1-4GlcA(3S)beta1-3GalNAc(4S), and GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcA(3S)beta1-3GalNAc(4S), where 3S or 4S represents 3-O- or 4-O-sulfate, respectively. The structure of the pentasaccharide was determined as GlcA(3S)beta1-3GalNAc(4S)beta1-4GlcA(3S)beta1- 3GalNAc(4S)beta1-4GlcA. Chondroitinase ABC digestion of the tetrasaccharides with GlcA(3S) at the internal position destroyed the disaccharide unit containing GlcA(3S) derived from the reducing side and resulted in only the disaccharide unit from the non-reducing side. In contrast, these tetrasaccharides remained totally resistant to chondroitinase AC-II. The results indicated that it is necessary to reevaluate the disaccharide composition of chondroitin sulfate poly- or oligosaccharides purified from various biological sources, since they were usually determined after chondroitinase ABC digestion. It is probable that the structures containing GlcA(3S) would not have been detected.     

A Novel Artificially Humanized Anti-Cripto-1 Antibody Suppressing Cancer Cell Growth

Cripto-1 is a member of the EGF-CFC/FRL1/Cryptic family and is involved in embryonic development and carcinogenesis. We designed a novel anti-Cripto-1 artificial antibody and assessed the recognition to the antigen and the potential to suppress the growth of cancer stem cells. First, single chain antibody clones were isolated by bio-panning with the affinity to recombinant Cripto-1 protein from our original phage-display library. Then, the variable regions of heavy chain VH and light chain VL in each clone were fused to constant regions of heavy chain CH and light chain CL regions respectively. These fused genes were expressed in ExpiCHO-S cells to produce artificial humanized antibodies against Cripto-1. After evaluation of the expression levels, one clone was selected and the anti-Cripto-1 antibody was produced and purified. The purified antibody showed affinity to recombinant Cripto-1 at 1.1 pmol and immunoreactivity to cancer tissues and cell lines. The antibody was available to detect the immunoreactivity in tissue microarrays of malignant tumors as well as in Cripto-1 overexpressing cells. Simultaneously, the antibody exhibited the potential to suppress the growth of human colon cancer derived GEO cells overexpressing Cripto-1 with IC₅₀ at approximately 110 nM. The artificially humanized antibody is proposed to be a good candidate to target cancer cells overexpressing Cripto-1.     

Colorimetric microdetermination of sulphites in foods by use of the modified rankine apparatus. IV.

Summary Detection and determination of traces of sulphites in foods was attempted by use of the modified Rankine apparatus and pararosaniline colorimetry. Replacement of alkaline titration reported previously by pararosaniline colorimetry lowered the absolute detection limit from 30 g (titration method) to 2 g. In view of clean analysis, in the color developing system, 0.1 N-sodium hydroxide was used in place of mercuric chloride solution commonly used as an absorbant of sulphites. In order to prevent oxidative decomposition of sulphites during operation, nitrogen gas was used as carrier instead of air. Dimedone and sodium azide were used for the elimination of aldehydes and nitrites, respecitvely, in the sample, which will disturb the color development of sulphites with pararosaniline-formaldehyde reagents. With this improved method, it was possible to determine the residual sulphites in frozen peeled shrimps, sugared beans and other foods with low sulphite contents accurately.

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Colorimetrische Mikrobestimmung von Sulfiten in Lebensmitteln bei Anwendung der modifizierten IV. Rankine Apparatur

Zusammenfassung Geringe Sulfitmengen in Lebensmitteln (geschälte Garnelen, gezuckerte Bohnen) können colorimetrisch bestimmt werden. Die neuentwickelte Methode beruht auf einer Kombination von colorimetrischer Bestimmung mittels p-Rosanilin und der Bestimmungsmethode nach Rankine. Auf diese Weise lassen sich Gehalte von 2 g noch genau bestimmen. Bei der Farbentwicklung wurde das giftige Quecksilbertetrachlorid durch 0.1 n-NaOH ersetzt, anstelle von Luft Stickstoff als Trägergas verwendet und somit eine Oxydation des Sulfits während der Bestimmung vermieden. Da Nitrit und Aldehyde die Farbentwicklung stören, wurde ihr Einfluß durch Dimedon und Natriumazid ausgeschaltet.

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Studies on the Analyses of Sulphites in Foods (IV)     

Anthocyanins,but not Anthocyanidins,from Bilberry (Vaccinium myrtillus L.) Alleviate Pruritus via Inhibition of Mast Cell Degranulation

Abstract: We have previously reported that bilberry anthocyanins exhibit an anti‐pruritic effect in a mouse model of allergic contact dermatitis. It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. The objective of this study was to compare the anti‐pruritic effect of anthocyanin‐rich quality‐controlled bilberry extract and anthocyanidin‐rich degraded extract using a mouse model of allergic contact dermatitis. BALB/c mice with allergic contact dermatitis induced by 4 weeks of repeated application of 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) were administered Bilberon‐25 orally for 4 weeks after sensitization with TNCB. The effect of Bilberon‐25 on pruritus was evaluated by measurement of scratching behavior. RBL‐2H3 mast cells were used to investigate the effect of Bilberon‐25 on degranulation in 48/80‐stimulated mast cells. Compared with nonheated Bilberon‐25, the proportion of anthocyanins in heated Bilberon‐25 decreased, and the proportion of anthocyanidins was increased in heated‐time dependent manner. Treatment with non‐heated Bilberon‐25 significantly attenuated the TNCB‐induced increase in scratching behavior, whereas treatment with 2 h‐heated Bilberon‐25 did not. Moreover, 300 μg/mL nonheated Bilberon‐25 showed significant inhibition of degranulation in RBL‐2H3 mast cells, whereas 2 h‐heated Bilberon‐25 had no effect at any concentration studied. It is assumed that the inhibitory effect of bilberry anthocyanins on pruritus might be mediated, at least in part, by its inhibitory effect on mast cell degranulation. In conclusion, the anthocyanin‐rich but not anthocyanidin‐rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.     

Analysis of 3D face forms for proper sizing and CAD of spectacle frames

Three-dimensional morphological variations in the human face were analysed using digital models of the human face, and the usefulness of such analysis in designing industrial products was demonstrated by validating spectacle frame designs based on an original sizing system developed based on the analysis. A normalized model of the three-dimensional face form was made for each of 56 young adult Japanese males. The morphological distances between subjects were defined, and subjects were divided into four groups based on analysis of the distance matrix. A prototype spectacle frame was designed for the average form of each of the four groups. Tightening force of the prototype frames was adjusted using the materialized average forms with soft material placed at the nasal bridge and side of the head. Four prototype frames as well as a conventional frame were evaluated using sensory evaluation and physical measurement of the pressure and slip in 38 young adult male subjects. For each of the 38 subjects, prototype frames were ranked according to the morphological similarity of the subjects and the average form of the four groups: the frame designed for the average form of the group most similar to the subject was #1, the frame designed for the average form of the next most similar group was #2, and so on. For the groups with smaller or narrower faces, new frame #1 was most preferred and had the best overall fit, smallest slip sensation and largest pressure sensation. The groups with larger or wider faces preferred tighter frames than new frame #1, because they were concerned that the frames might slip, although the frames did not. Most of the subjects habitually wore spectacles, and the reason that groups with larger or wider faces preferred tighter frames was thought to be that they were accustomed to tighter fitting frames.     

Thermal degradation and ageing behavior of microcomposites of natural rubber,carboxylated styrene butadiene rubber latices,and their blends

The effect of microfillers on the thermal stability of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) latices, and their 70/30 NR/XSBR blend were studied using thermogravimetric method. Microcomposites of XSBR and their blend were found to be thermally more stable than unfilled samples. The activation energy needed for the degradation of polymer chain was calculated from Coats‐Redfern plot. Activation energy needed for the thermal degradation of filled samples was higher than unfilled system. It indicated the improved thermal stability of the filled samples. The ageing resistance of the micro‐filled samples was evaluated from the mechanical properties of aged samples. The thermal ageing was carried out by keeping the samples in hot air oven for 7 days at 70°C. The mechanical properties such as tensile strength, modulus at 300% elongation, and strain at break were computed. As compared to unfilled samples, micron‐sized fillers reinforced systems exhibited higher ageing resistance. Finally, an investigation was made on the influence of ion‐beam irradiation on microcomposites of NR, XSBR latices, and their 70/30 blend systems using ²⁸Si⁸⁺ performed at 100 MeV. The surface changes of the samples after irradiation were analyzed using X‐ray photoelectron spectroscopy. The results of XPS measurements revealed that the host elements were redistributed without any change in binding energies of C_1s, O_1s, and Si_2p. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Dynamic voltage and frequency management for a low-power embedded microprocessor

High-performance and low-power microprocessors are key to PDA applications. A dynamic voltage and frequency management (DVFM) scheme with leakage power compensation effect is introduced in a microprocessor with 128-bit wideband 64-Mb embedded DRAM. The DVFM scheme autonomously controls clock frequency from 8 to 123 MHz in steps of 0.5 MHz and also adaptively controls supply voltage from 0.9 to 1.6 V in steps of 5 mV, achieving 82% power reduction in personal information management scheduler application and 40% power reduction in MPEG4 movie playback. This low-power embedded microprocessor, fabricated with 0.18-/spl mu/m CMOS embedded DRAM technology, enables high-performance operations such as audio and video applications. As process technology shrinks, this adaptive leakage power compensation scheme will become more important in realizing high-performance and low-power mobile consumer applications.     

Review of pulmonary toxicity of indium compounds to animals and humans

Due to the increased production of ITO, the potential health hazards arising from occupational exposure to this material have attracted much attention. This review consists of three parts: 1) toxic effects of indium compounds on animals, 2) toxic effects of indium compounds on humans, and 3) recommendations for preventing exposure to indium compounds in the workplace.Available data have indicated that insoluble form of indium compounds, such as ITO, indium arsenide (InAs) and indium phosphide (InP), can be toxic to animals. Furthermore, InP has demonstrated clear evidence of carcinogenic potential in long-term inhalation studies using experimental animals. As for the dangers to humans, some data are available concerning adverse health effects to workers who have been exposed to indium-containing particles. The Japan Society for Occupational Health recommended the value of 3 μg/L of indium in serum as the occupational exposure limit based on biological monitoring to preventing adverse health effects in workers resulting from occupational exposure to indium compounds. Accordingly, it is essential that much greater attention is focused on human exposure to indium compounds, and precautions against possible exposure to indium compounds are most important with regard to health management among indium-handling workers.