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.     

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.     

LES analysis of flow and turbulent mixing in an unsteady jet

The flow and mixing process of unsteady jets are fundamentally analyzed by large eddy simulations. The effects of nozzle velocity and turbulence intensity on the turbulent eddy structure and mixing process between the nozzle fluid and ambient fluid were investigated. The results show that a toroidal‐shaped vortex, which emerges around the jet tip, primarily accelerates the entraining flow. Also, increasing the turbulence intensity in the nozzle encourages mixing in the jet without changing the jet‐contour. Furthermore, when the rise‐up time of the initial nozzle velocity is elongated, turbulent mixing is suppressed. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(5): 303–313, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20158     

Fractures of the base of the middle phalanx of the finger. Classification, management and long-term results

We classified fractures of the base of the middle phalanx into five types: 1) single palmar fragment; 2) single dorsal fragment; 3) two main fragments; 4) not involving the articular surface, including epiphyseal separation in children; and 5) all others. Types 1 and 2 were subclassified into avulsion, split and split-depression. Surgery is recommended for unstable type-1 avulsion fractures, type-2 avulsions which may develop buttonhole deformities, and all fractures which displace articular cartilage surfaces. Long-term follow-up showed that surgical treatment which produced good stability and congruity gave good results. These should be the primary aims of treatment.     

A long-term follow-up study of serial magnetic resonance images in patients with delayed encephalopathy after acute carbon monoxide poisoning

We report a case of vasculitis in a 67-year-old woman who successively developed over a four-month period clinical manifestations suggestive of rheumatoid arthritis, lupus, sicca, syndrome and finally giant cell arteritis. All her symptoms resolved promptly upon discontinuation of enalapril and none recurred over the five-year follow-up period. The only residual manifestation is Jaccoud's arthropathy of the hands.     

Determination of cyanide in whole blood by capillary gas chromatography with cryogenic oven trapping

Cyanide, one of the most important toxic substances, has been found measurable with high sensitivity by capillary gas chromatography (GC) with cryogenic oven trapping upon injection of headspace (HS) vapor samples. The entire amount of cyanide in the HS sample could be cryogenically trapped prior to on-line GC analysis. A 0.5-mL volume of blood in the presence or absence of cyanide and propionitrile (internal standard, IS) was added to a vial containing 0.25 mL of distilled water, 0.3 g of Na2-SO4, 0.2 mL of 50% H3PO4, and 0.1 g of ascorbic acid (when needed), and the mixture was heated at 70 degrees C for 15 min. A 5-mL volume of the HS vapor was introduced into a GC capillary column in the splitless mode at -30 degrees C oven temperature that was programmed up to 160 degrees C for GC analysis with nitrogen-phosphorus detection. A sharp peak was obtained for cyanide under the present conditions, and backgrounds were very clean. The extraction efficiencies of cyanide and IS were 2.89-3.22 (100 or 500 ng/mL) and 2.42%, respectively. The calibration curve showed good linearity in the range of 25-1000 ng/mL and the detection limit was approximately 2 ng/mL. The coefficients of intraday and interday variations were 2.9 and 11.8%, respectively. The mean blood cyanide level measured for actual fire victims was 687 +/- 597 ng/mL (mean +/- SD, n = 9). Endogenous blood cyanide concentration for healthy subjects was 8.41 +/- 3.09 ng/mL (mean +/- SD, n = 6).