Comparative study on the modulation of IgE and cytokine production by Phellinus linteus grown on germinated brown Rice, Phellinus Linteus and germinated brown rice in murine splenocytes

We compared the immunomodulating activities in mice of extracts from Phellinus linteus grown on germinated brown rice (PB), Phellinus linteus (PL) alone, and germinated brown rice (BR) alone. The PL, BR and PB-treated mice were administered with the respective extract (2 mg/head/day) by oral gavage for 4 weeks. All extracts markedly decreased the IgE production and allergic responses in serum and splenocytes. PL and PB increased the proportion of CD4(+) but not CD8(+) T cells in splenocytes. Cytokine production was significantly augmented in all treated mice; the concentration of IFN-gamma was greater in the PL, BR and PB mice than in the control group. The concentration of IL-10 was lower in the BR group than in the other groups. These results may be related to the suppression of IgE production. We conclude that PB modulated the immune responses of IgE production and Th1/Th2 cytokine secretion in murine splenocytes.     

Independent genetic mechanisms mediate turgor generation and penetration peg formation during plant infection in the rice blast fungus

The first barrier to infection encountered by foliar pathogens is the host cuticle. To traverse this obstacle, many fungi produce specialized infection cells called appressoria. MST12 is essential for appressorium-mediated penetration and infectious growth by the rice pathogen Magnaporthe grisea. In this study, we have characterized in detail the penetration defects of an mst12 deletion mutant. Appressoria formed by the mst12 mutant developed normal turgor pressure and ultrastructure but failed to form penetration pegs either on cellophane membranes or on plant epidermal cells. Deletion and site-directed mutagenesis analyses indicated that both the homeodomain and zinc finger domains, but not the middle region, of MST12 are essential for appressorial penetration and plant infection. The mst12 mutant appeared to be defective in microtubule reorganization associated with penetration peg formation. In mature appressoria, the mutant lacked vertical microtubules observed in the wild type. The mst12 mutant also failed to elicit localized host defence responses, including papilla formation and autofluorescence. Our data indicate that generation of appressorium turgor pressure and formation of the penetration peg are two independent processes. MST12 may play important roles in regulating penetration peg formation and directing the physical forces exerted by the appressorium turgor in mature appressoria.     

Chaga mushroom extract inhibits oxidative DNA damage in human lymphocytes as assessed by comet assay

The Chaga mushroom (Inonotus obliquus) is claimed to have beneficial properties for human health, such as anti-bacterial, anti-allergic, anti-inflammatory and antioxidant activities. The antioxidant effects of the mushroom may be partly explained by protection of cell components against free radicals. We evaluated the effect of aqueous Chaga mushroom extracts for their potential for protecting against oxidative damage to DNA in human lymphocytes. Cells were pretreated with various concentrations (10, 50, 100 and 500 microg/mL) of the extract for 1 h at 37 degrees C. Cells were then treated with 100 microM of H2O2 for 5 min as an oxidative stress. Evaluation of oxidative damage was performed using single-cell gel electrophoresis for DNA fragmentation (Comet assay). Using image analysis, the degree of DNA damage was evaluated as the DNA tail moment. Cells pretreated with Chaga extract showed over 40% reduction in DNA fragmentation compared with the positive control (100 micromol H2O2 treatment). Thus, Chaga mushroom treatment affords cellular protection against endogenous DNA damage produced by H2O2.     

Green vegetable drink consumption protects peripheral lymphocytes DNA damage in Korean smokers

Smoking increases indices of free radical-mediated damage of DNA which are potential underlying processes in the pathogenesis of many diseases. In this study, we evaluated whether 8 weeks of green vegetable drink (Angelica keiskei based juice) supplementation to smokers can be protective against lymphocytic DNA damage. Twenty smokers were given 240 ml of commercially available green vegetable drink every day for 8 weeks. The DNA damage was determined using single cell gel electrophoresis (COMET assay) and the damage was quantified by measuring tail length (TL), tail moment (TM), and percent DNA in tail. Eight weeks of green vegetable drink consumption resulted in a significant in lymphocytes DNA damage in all three measurements; TL, TM and % DNA in tail. These results support the hypothesis that green vegetable drink exerts a cancer-protective effect via a decrease in oxidative damage to DNA in humans.     

Cortisol and IGF-1 synergistically up-regulate taurine transport by the rat skeletal muscle cell line, L6

This study was undertaken to evaluate effects of exercise-induced hormones, cortisol, IGF-1, and beta-endorphin, on the regulation of taurine transport activity in rat skeletal myoblasts, L6 cells. Challenge of L6 cells with cortisol (100 nM) for 24 hrs resulted in a 165% increase in taurine transport activity, 220% increase in Vmax of the taurine transporter, and 55% increase in taurine transporter/ beta-actin mRNA level compared with untreated control cells. Neither IGF-1 (1 approximately 100 nM) nor beta-endorphin (1 approximately 20 nM), added in the incubation medium separately for 24 hrs, affected taurine uptake by L6 cells. However, when cells were co-treated with IGF-1 (10 nM) plus cortisol (100 nM), taurine transport activity (37% increase, p < 0.05), Vmax of the transporter (54%, p < 0.05), and taurine transporter/ beta-actin mRNA level were further increased compared to the value for cells treated with cortisol alone. These results suggest that taurine transport by skeletal muscle cells appear to be synergistically up-regulated during a prolonged exercise via elevated levels of cortisol and IGF-1 in muscle.     

Comparison of estrogen and genistein in their antigenotoxic effects, apoptosis and signal transduction protein expression patterns

The antigenotoxic effects of estrogen and genistein (isoflavones) were compared by measuring the degree of protection against plasmid DNA strand breakage induced by peroxyl free radicals using the DNA strand scission assay with pBR322 DNA. Isoflavones decreased DNA strand breakage by AAPH radical treatment at the all of three concentrations tested (0.5, 1.0, 1.5 microg/ml) with the range of 89.5% to 99.6%. Compared to genistein, estrogen was not as effective as genistein showing 46.9% to 29.6% protection, and this protective effect was decreased as estrogen concentrations increased from 0.1 to 0.3 microg/ml. DNA ladder experiments showed that genistein induced apoptosis in cultured cell lines, whereas estrogen did not induce any apoptosis. The effects of cell signal trandsduction protein expression patterns were compared between estrogen and genistein. The increased expression of cyclin B1 by estrogen was tampered by genistein at the highest concentration. Antigenotoxic and antiproliferative effects of genistein shown in this study support the hypothesis that it has a chemopreventive effect against particular types of cancers.     

Evaluation of a high-affinity QCM immunosensor using antibody fragmentation and 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer

This study evaluated construction of a highly affinitive quartz crystal microbalance (QCM) immunosensor using anti-C-reactive protein (CRP) antibody and its fragments for CRP detection. Three types of antibody were immobilized on the surface of a QCM via covalent-bounding. Then affinity was evaluated through antigen-antibody binding between CRP and its antibody. Affinity between antigen-antibody was shown to be highest when anti-CRP F(ab')2-IgG antibody (70 microg/mL) was immobilized on the QCM. In case of anti-CRP F(ab')2-IgG antibody, affinity which was attributable to antigen-antibody binding was almost twice that of anti-CRP IgG antibody, which is used conventionally for QCM immunosensors. In addition, when it was treated with 2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate, so-called MPC polymer, highly affinitive and selective immunosensing for CRP was achieved without non-specific binding from plasma proteins in human serum. When anti-CRP F(ab')2-IgG antibody was immobilized on the QCM, the detection limit and the linearity of CRP calibration curve were achieved at concentrations from 0.001 to 100 microg/dL even during investigation in serum samples. Experimental results verified the successful construction of a highly affinitive and selective QCM-immunosensor which was modified with anti-CRP F(ab')2-IgG antibody and MPC polymer.     

A plethora of painful molecules

Pain is a fundamental experience with a complex and multi-layered neurobiological basis. In recent years a powerful battery of techniques has been brought to bear to unravel the mechanisms by which painful stimuli are transduced and processed. There have been several recent discoveries regarding the molecular transduction mechanisms in nociceptors and novel molecular and cellular mechanisms underlying the spinal processing of painful stimuli. The mechanisms by which sensory neurons initiate hyperalgesia and touch evoked pain (allodynia) have been addressed particularly successfully in recent studies. The rich variety of key molecular players that have emerged in physiological and pathophysiological pain states reflects the sophistication and uniqueness of this vitally important sense.     

Thoracic vein ablation terminates chronic atrial fibrillation in dogs

The thoracic vein hypothesis of chronic atrial fibrillation (AF) posits that rapid, repetitive activations from muscle sleeves within thoracic veins underlie the mechanism of sustained AF. If this is so, thoracic vein ablation should terminate sustained AF and prevent its reinduction. Six female mongrel dogs underwent chronic pulmonary vein (PV) pacing at 20 Hz to induce sustained (>48 h) AF. Bipolar electrodes were used to record from the atria and thoracic veins, including the vein of Marshall, four PVs, and the superior vena cava. Radio frequency (RF) application was applied around the PVs and superior vena cava and along the vein of Marshall until electrical activity was eliminated. Computerized mapping (1,792 electrodes, 1 mm resolution) was also performed. Sustained AF was induced in 30.6 +/- 6.5 days, and ablation was done 17.3 +/- 8.5 days afterward. Before ablation, the PVs had shorter activation cycle lengths than the atria, and rapid, repetitive activations were observed in the PVs. All dogs converted to sinus rhythm during (n = 4 dogs) or within 90 min of completion of RF ablation. Rapid atrial pacing afterward induced only nonsustained (<60 s) AF in all dogs. Average AF cycle lengths after reinduction were significantly (P = 0.01) longer (183 +/- 31.5 ms) than baseline (106 +/- 16.2 ms). There were no activation cycle length gradients after RF application. We conclude that thoracic vein ablation converts canine sustained AF into sinus rhythm and prevents the reinduction of sustained AF. These findings suggest that thoracic veins are important in the maintenance of AF in dogs.