Masahiro Kaneko

Suppressive Effects of the Flavonoids Quercetin and Luteolin on the Accumulation of Lipid Rafts after Signal Transduction via Receptors

Quercetin (QUER) and luteolin (LUTE) are dietary flavonoids capable of regulating the production of cytokines, such as tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). However, their mechanisms of action are not fully understood. In lipopolysaccharide-triggered (LPS)-triggered signaling via Toll-like receptor 4 (TLR4), QUER and LUTE suppresses not only the degradation of the inhibitor of κB (IκB), with resultant activation of nuclear factor-κB (NF-κB), but also the phosphorylation of p38 and Akt in bone marrow-derived macrophages that have been stimulated with LPS. We report here that, in TNF-α-induced signaling, QUER and LUTE significantly suppressed the production of IL-6 and activation of NF-κB. Accumulation of lipid rafts, the initial step in the signaling pathway, was significantly inhibited when macrophages were treated with QUER or with LUTE prior to exposure to LPS. Similarly, the accumulation of lipid rafts was inhibited by the flavonoids when B cells were activated via the membrane IgM and when T cells were activated via CD3. In contrast, QUER and LUTE did not inhibit the activation of phorbol myristate acetate-induced NF-κB in macrophages. Our observations suggest that QUER and LUTE interact with receptors on the cell surface and suppress the accumulation of lipid rafts that occurs downstream of the activation of the receptors.

Amelioration of Skewed Th1/ Th2 Balance in Tumor-Bearing and Asthma-Induced Mice by Oral Administration of Agaricus blazei Extracts

We showed in a previous study that hot-water extracts of Agaricus blazei (Agaricus extracts) had anti-tumor activity to Meth A fibrosarcoma, but it remains unclear whether the Agaricus extracts ameliorate the skewed balance of type-1 T helper (Th1) and type-2 T helper (Th2) cells. We examined whether Agaricus extracts effect the skewed Th1/Th2 balance in tumor-bearing and asthma-induced mice. When Meth A-bearing mice were given orally either Agaricus extracts or water once a day starting 5 days after tumor implantation, spleen T cells, prepared from tumor-bearing mice treated with Agaricus extracts, in response to anti-CD3 monoclonal antibody produced significantly higher levels of interferon γ (IFN-γ) than that of controls. The mRNA expression of IFN-γ-inducing protein 10 and the frequency of CD69+ or CD49d+ cells, among activated T cells infiltrated into tumors, significantly increased in Agaricus-treated mice, compared with those of tumor-controls. In asthma-induced mice, treatment with the Agaricus extracts caused significant downregulation of OVA-specific antibody responses of IgG1 and IgE but not of IgG2a, and significantly decreased total cell numbers, levels of interleukin 5, and eosinophil numbers in bronchial alveolar lavage fluids. IFN-γ production by anti-CD3-stimulated spleen cells, obtained from Agaricus-treated mice, significantly increased. Our results strongly suggest that oral administration of Agaricus extracts ameliorates the Th1/Th2 balance from the Th2-skewed conditions.

An extraction algorithm of pulmonary fissures from multislice CT image

Aging and smoking history increases number of pulmonary emphysema. Alveoli restoration destroyed by pulmonary emphysema is difficult and early direction is important. Multi-slice CT technology has been improving 3-D image analysis with higher body axis resolution and shorter scan time. And low-dose high accuracy scanning becomes available. Multi-slice CT image helps physicians with accurate measuring but huge volume of the image data takes time and cost. This paper is intended for computer added emphysema region analysis and proves effectiveness of proposed algorithm.

Accelerated recovery from γ-irradiation-induced leukopenia in mice by the biscoclaurine alkaloid, cepharanthin® : comparison with recombinant human granulocyte colony-stimulating factor

Abstract The effect of a biscoclaurine alkaloid drug, Cepharanthin ® (CE), on recovery from severe leukopenia induced by whole body γ-irradiation at a dose of 3 Gy, was compared with that of recombinant human granulocyte colony-stimulating factor (rhG-CSF). Daily intraperitoneal administration of 100 μg CE into the irradiated mice significantly prevented decrease of leukocyte numbers in the peripheral blood and accelerated recovery from leukopenia to normal. The activity of CE was somewhat weaker than that of 20,000 units of rhG-CSF when administered daily subcutaneously. In cell composition of peripheral leukocytes, CE increased the numbers of polymorphonuclear (PMN) cells and lymphocytes compared with those of the irradiated controls. Stronger change in PMN cell numbers than with CE was induced by administration of rhG-CSF. No significant increment of the activity to form colonies in spleen (colony-forming unit in spleen; CFU-S) was observed in bone marrow cells from irradiated donor mice administered CE, though CE induced CSF production into sera. Administration of rhG-CSF stimulated the CFU-S activity. These results indicate that CE increased recruitment of PMN cells from the marginal pool rather than the stimulation of pluripotent stem cells in the bone marrow.

Detection algorithm of lung cancer candidate nodules on multislice CT images

Recently, multi-slice helical CT technology was developed. Unlike the conventional helical CT, we can obtain CT images of two or more slices with 1 time of scan. Therefore, we can get many pictures with a clear contrast images and thin slice images in one time of scanning. The nodule is expected to be picture more clearly, and it is expected an high diagnostic ability of screening by the expert physicians. Multi-slice CT is z-axial high-contrast resolution, but the number of images is 10 times the single-slice helical CT. Therefore, the development of a diagnosis support system is expected to diagnose these images. We have developed a computer aided diagnosis (CAD) system to detect the lung cancer from multi-slice CT images. Using the conventional algorithm, it was difficult to detect the ground glass shadow and the nodules in contact with the blood vessel. The purpose of this study is to develop a detection algorithm using the 3-D filter by orientation map of gradient vectors and the 3-D distance transformation.

Inhibitory effects of fermented grape marc from Vitis vinifera Negroamaro on antigen-induced degranulation

To investigate the antiallergic effects of fermented grape marc from Negroamaro (N-FGM), we examined antigen (Ag)-induced degranulation of rat basophilic leukemia (RBL-2H3) cells. Among supernatants of N-FGM suspensions in water, ethanol, and dimethyl sulfoxide (DMSO), supernatants of DMSO-suspended N-FGM but not of nonfermented Negroamaro grape marc (N-GM) markedly suppressed the Ag-induced degranulation and phosphorylation of Syk in RBL-2H3 cells. Supernatants of DMSO-suspended N-FGM did not reduce the expression of FcϵRI on RBL-2H3 cells. Analyses of supernatants of N-FGM suspensions in water, ethanol, and DMSO by high-performance liquid chromatography revealed higher amounts of quercetin in supernatants of DMSO-suspended N-FGM than those in the other supernatants. Quercetin also suppressed the Ag-induced degranulation and phosphorylation of Syk but did not reduce the expression of FcϵRI on RBL-2H3 cells. These results suggest that inhibition of the Ag-induced degranulation and Syk phosphorylation by N-FGM might be due to the action of quercetin, as an active component in N-FGM.

Quercetin but not luteolin suppresses the induction of lethal shock upon infection of mice with Salmonella typhimurium.

Tumor necrosis factor-alpha (TNF-alpha) is important for the induction of systemic inflammatory responses that lead to lethal shock. Quercetin and luteolin, which differ by one hydroxyl group, are known to suppress the lipopolysaccharide-induced production of TNF-alpha in vitro. We show differing inhibitory effects of quercetin and luteolin on the induction of lethal shock in Salmonella typhimurium aroA-infected mice. In a time- and dose-dependent manner, quercetin reduced the plasma levels of TNF-alpha, lowered bacterial titers in livers, prevented liver damage and prolonged survival, while luteolin had little or no effect. Compared with luteolin, quercetin increased the infiltration of Gr-1(+)CD69(+) neutrophils into the peritoneal cavity and lowered heat shock protein 70 expression. Obviously, the additional hydroxyl group in quercetin is important for suppressing infection-induced lethal shock in mice.

CAD system for lung cancer based on low-dose single-slice CT image

We have been developed a computer-aided diagnosis (CAD) system for the lung cancer detection of early stage from low dose single-slice computed tomography (CT) with 10 mm beam width on chest screening. The objective of this study is to solve three problems of the conventional CAD system; (1) lesion which overlaps blood vessel, (2) lesion in contact with blood vessel and (3) lesion near upper mediastinum. This paper presents a new method to solve problem-1 and problem-2. The blood vessels, which overlap lesions and others in contact with lesion, are eliminated by detecting region of interest (ROI) with accuracy. Detection method of ROIs consists of 3 processes; firstly, streak shadows elimination using linear feature detector filter, secondly, estimation of pulmonary background bias using the intensity histogram and the opening method, and finally, ROIs border detection using laplacian filter. We evaluated the new system by apply it to 155 shadows which need confirmation diagnosis. These cases were selected from clinical test from July 1997 to December 2000 in retrospective study. True positive cases of this algorithm achieved sensitivity 91.0 %. The average of false positive cases was 0.53 per slice.

Mechanism of up-regulation of immunoglobulin A production in the intestine of mice unresponsive to lipopolysaccharide

The mechanisms by which immunoglobulin A (IgA) production up‐regulates in the intestine of Toll‐like receptor‐4 (TLR4)‐mutated mice were investigated. When TLR4‐mutated, C3H/HeJ and BALB/lpsd mice received oral administration of cholera toxin (CT), not only CT‐specific IgA levels in the intestinal lavage but also the number of IgA‐producing cells in intestinal lamina propria (iLP) significantly increased compared with those of the wild‐type C3H/He and BALB/c mice. Interleukin (IL)‐5‐producing cells and CD86+ cells in iLP also significantly increased in C3H/HeJ mice. The expression of major histocompatibility complex class II and CD86 on cells present in Peyers patches (PPs) of C3H/HeJ mice was higher than those of C3H/He mice. In non‐immunized C3H/HeJ mice, the expression of transforming growth factor‐β (TGF‐β) mRNA and the percentages of IL‐10‐producing cells in PPs but not in spleen increased when compared with those in C3H/He mice. The suppressor of cytokine signalling‐1 (SOCS‐1) was expressed in PPs of C3H/He mice but not C3H/HeJ mice. These results indicate that high IgA levels in the intestine of TLR4‐mutated mice are due to up‐regulation of TGF‐β and IL‐10 and the lack of regulation by SOCS‐1.

Computer-aided differential diagnosis of pulmonary nodules based on a hybrid classification approach

We are developing computerized feature extraction and classification methods to analyze malignant and benign pulmonary nodules in 3D thoracic CT images. Internal structure features were derived form CT density and 3D curvatures to characterize the inhomogeneous of CT density distribution inside the nodule. In the classification step, we combined an unsupervised k-means clustering (KMC) procedure and a supervised linear discriminate (LD) classifier. The KMC procedure classified the sample nodules into two classes by using the mean CT density values for two different regions such as a core region and a complement of the core region in 3D nodule image. The LD classifier was designed for each class by using internal structure features. The forward stepwise procedure was used to select the best feature subset from multi-dimensional feature spaces. The discriminant scores output form the classifier were analyzed by receiver operating characteristic (ROC) method and the classification accuracy was quantified by the area, Ax, under the ROC curve. We analyzed a data set of 248 pulmonary nodules in this study. The hybrid classifier was more effective than the LD classifier alone in distinguishing malignant and benign nodules. The improvement was statistically significant in comparison to classification in the LD classifier alone. The results of this study indicate the potential of combining the KMC procedure and the LD classifier for computer-aided classification of pulmonary nodules.