Gamma-carboline derivatives with anti-bovine viral diarrhea virus (BVDV) activity

Based on anti-viral screening of our heteroaromatics derived from thalidomide, the gamma-carboline skeleton has been identified as a superior scaffold structure for compounds with potent anti-bovine viral diarrhea virus (BVDV) activity. Structural development studies led to a potent anti-viral agent, SK5M (5-methyl-gamma-carboline), with the EC(50) of 0.26 microM.     

Malondialdehyde generated from peroxidized linolenic acid causes protein modification in heat-stressed plants

When polyunsaturated fatty acids (PUFAs) in biomembrane are peroxidized, a great diversity of aldehydes is formed, and some of which are highly reactive. Thus they are thought to have biological impacts in stressed plants; however, the detailed mechanism of generation and biochemical effects are unknown. In this study, we show that chloroplasts are major organelles in which malondialdehyde (MDA) generated from peroxidized linolenic acid modifies proteins in heat-stressed plants. First, to clarify the biochemical process of MDA generation from PUFAs and its attachment to proteins, we carried out in vitro experiments using model proteins (BSA and Rubisco) and methylesters of C18 PUFAs that are major components of plant biomembrane. Protein modification was detected by Western blotting using monoclonal antibodies that recognize MDA binding to proteins. Results showed that peroxidation of linolenic acid methylester by reactive oxygen species was essential for protein modification by MDA, and the MDA modification was highly dependent on temperature, leading to a loss of Rubisco activity. When isolated spinach thylakoid membrane was peroxidized at 37 degrees C, oxygen-evolving complex 33kDa protein (OEC33) was modified by MDA. These model experiments suggest that protein modification by MDA preferentially occurs under higher temperatures and oxidative conditions, thus we examined protein modification in heat-stressed plants. Spinach plants were heat-stressed at 40 degrees C under illumination, and modification of OEC33 protein by MDA was detected. In heat-stressed Arabidopsis plants, light-harvesting complex protein was modified by MDA under illumination. This modification was not observed in linolenic acid-deficient mutants (fad3fad7fad8 triple mutant), suggesting that linolenic acid is a major source of protein modification by MDA in heat-stressed plants.     

Induction of distinct sets of secretory phospholipase A2 in rodents during inflammation

Although the expression of the prototypic secretory phospholipase A₂ (sPLA₂), group IIA (sPLA₂-IIA), is known to be up-regulated during inflammation, it remains uncertain if other sPLA₂ enzymes display similar or distinct profiles of induction under pathological conditions. In this study, we investigated the expression of several sPLA₂s in rodent inflammation models. In lipopolysaccharide (LPS)-treated mice, the expression of sPLA₂-V, and to a lesser extent that of sPLA₂-IID, -IIE, and -IIF, were increased, whereas that of sPLA₂-X was rather constant, in distinct tissues. 12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema, in which the expression of sPLA₂-IID, -IIF and -V was increased, was significantly reduced by YM-26734, a competitive sPLA₂-IIA inhibitor that turned out to inhibit sPLA₂-IID, -IIE, -V and -X as well. In contrast, sPLA₂-IIA was dominant in carageenin-induced pleurisy in rats, where the accumulation of exudate fluids and leukocytes was significantly ameliorated by YM-26734. These results indicate that distinct sPLA₂s can participate in inflammatory diseases according to tissues, animal species, and types of inflammation.     

Murine NKT cells produce Th17 cytokine interleukin-22

Natural killer T (NKT) cells are known to produce Th17 cytokine IL-17 in addition to Th1/2 cytokines. In this study, the ability of NKT cells to produce IL-22, another Th17 cytokine, was examined in mice. When murine spleen cells were stimulated with α-galactosyl ceramide, a ligand for NKT cells, not only Th1/2 cytokines (IFN-γ, IL-4) but Th17 cytokines (IL-17, IL-22) were produced. NKT cells isolated from splenocytes released IL-17 and IL-22 following CD3, CD3/IL-2 or CD3/CD28 stimulation, in which CD3/CD28 costimulation was most effective. Production of IL-17 and IL-22 in CD4+ and CD8+ T cells from splenocytes was little, if any, even after CD3/CD28 costimulation. Treatment with IL-6/TGF-β decreased CD3/CD28-stimulated production of IL-22, but not that of IL-17, in NKT cells. These findings show for the first time that NKT cells are a cell source of IL-22, and that expression of two Th17 cytokines might be regulated in NKT cells by different mechanisms.     

Effects of gestational exposure to 1.95‐GHz W‐CDMA signals for IMT‐2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats

The present study was designed to evaluate whether gestational exposure to an EMF targeting the head region, similar to that from cellular phones, might affect embryogenesis in rats. A 1.95‐GHz wide‐band code division multiple access (W‐CDMA) signal, which is one applied for the International Mobile Telecommunication 2000 (IMT‐2000) system and used for the freedom of mobile multimedia access (FOMA), was employed for exposure to the heads of four groups of pregnant CD(SD) IGS rats (20 per group) for gestational days 7–17. The exposure was performed for 90 min/day in the morning. The spatial average specific absorption rate (SAR) for individual brains was designed to be 0.67 and 2.0 W/kg with peak brain SARs of 3.1 and 7.0 W/kg for low (group 3) and high (group 4) exposures, respectively, and a whole‐body average SAR less than 0.4 W/kg so as not to cause thermal effects due to temperature elevation. Control and sham exposure groups were also included. At gestational day 20, all dams were killed and fetuses were taken out by cesarean section. There were no differences in maternal body weight gain. No adverse effects of EMF exposure were observed on any reproductive and embryotoxic parameters such as number of live (243–271 fetuses), dead or resorbed embryos, placental weights, sex ratios, weights or external, visceral or skeletal abnormalities of live fetuses. Bioelectromagnetics 30:205–212, 2009. © 2008 Wiley‐Liss, Inc.     

Tonometric biosensor with a differential pressure sensor for chemo-mechanical measurement of glucose

A tonometric biosensor for glucose was constructed using a chemo-mechanical reaction unit and a differential pressure sensor. The reaction unit was fabricated by using both liquid and gas cells separated by an enzyme diaphragm membrane, in which glucose oxidase was immobilized onto the single (gas cell) side of the dialysis membrane. By applying glucose solution (0, 25.0, 50.0, 100, 150 and 200 mmol/l) into the liquid cell of the chemo-mechanical reaction unit, the pressure in the gas cell decreased continuously with a steady de-pressure slope because the oxygen consumption in the gas cell was induced by the glucose oxidase (GOD) enzyme reaction at the enzyme side of the porous diaphragm membrane. The steady de-pressure slope in the gas cell showed the linear relationship with the glucose concentration in the liquid cell between 25.0 and 200.0 mmol/l (correlation coefficient of 0.998). A substrate regeneration cycle coupling GOD with l-ascorbic acid (AsA: 0, 1.0, 3.0, 10.0 and 50.0 mmol/l; as reducing reagent system) was applied to the chemo-mechanical reaction unit in order to amplify the output signal of the tonometric biosensor. 3.0 mmol/l concentration of AsA could optimally amplify the sensor signal more than 2.5 times in comparison with that of non-AsA reagent.