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Background Atherosclerosis is a progressing inflammatory response mediated by various signaling molecules among which nuclear factor κB (NF-κB) is thought to have a pivotal role. This study demonstrated the efficacy of antioxidant MCI-186 in preventing the progression of atherosclerosis by inhibiting signaling molecules such as NF-κB. Methods and Results Balloon injury of intima was performed in the right common carotid artery of Japanese male white rabbits, which were then fed a 1% high cholesterol diet for 4 weeks, after assigning them to either the control (n=7) or MCI-186 (0.5 mg ·kg-1 · day-1, n=7) group. Histological analysis revealed a reduction in neointimal thickness and lipid deposition in the subendothelial area of the MCI-186 group. Immunohistochemical analysis revealed attenuation of E-selectin expression, macrophage migration and proliferation of smooth muscle cells in the MCI-186 treated group. In in vitro studies, rabbit aorta smooth muscle cells were incubated with rIL-1βin either the presence or absence of MCI-186. MCI-186 significantly inhibited rIL-1β-induced proliferation of smooth muscle cells from rabbit aorta, as well as the activation of NF-κB. Moreover, western blot analysis showed the inhibitory action of MCI-186 on the nuclear translocation of NF-κB in human umbilical vein endothelial cells under rIL-1βstimulation. Conclusions MCI-186 could provide a novel therapeutic strategy for atherosclerosis by inhibiting the NF-κB pathway. (Circ J 2008; 72: 800 - 806)

Bilirubin, a strong intrinsic antioxidant, quenches free radicals produced under inflammatory conditions. The oxidized bilirubin metabolites, i.e. biopyrrins, are immediately excreted into urine and can indicate the intensity of oxidation in vivo. Our preliminary studies suggested the involvement of reactive nitrogen species (RNS) in generation of biopyrrins. However, little is known about biological significance of bilirubin oxidation by RNS. Here, we analyzed the correlation between bilirubin oxidation and nitric oxide (NO) radicals during rat acute cardiac allograft rejection. In allograft recipients, urinary biopyrrins steeply increased on day 3 prior to the increase in myocardial tissue damage marker, serum troponin-T. In contrast, no significant changes in urinary biopyrrins were evident in recipients of isografts or cyclosporine-A treated allografts. Urinary nitrotyrosine, a marker of oxidation by NO radicals also increased on day 3, while administration of a NO synthase inhibitor, N(G)-monomethyl-L-arginine apparently diminished the elevation of urinary biopyrrins as well as nitrotyrosine. Immunohistochemistry revealed enhanced local expression of heme oxygenase-1, biopyrrins and nitrotyrosine in allografts in accordance with the cellular infiltrates, suggesting that changes in urinary biopyrrins reflect the bilirubin oxidation in grafts undergoing rejection. These results indicate that locally evoked bilirubin oxidation by NO radicals can predict the progression of rejection.

Anti-oxidants are essential for intracellular free radical scavenging, as free radicals are one of the causes for tumorigenesis. Our objective was to use bilirubin and investigate its action on human carcinoma cell lines. Bilirubin manifested as a prooxidant showing its cytopathic effect on TMK-1, showing growth inhibition close to 50%. Cell cycle analysis showed an arrest at G0/G1. Flow cytometry investigations with Red CC-1 showed an increase by more than 2 times suggesting a prooxidative role of bilirubin. To check the effect of radicals on DNA, a Comet Assay displayed a typical comet's tail with bilirubin treated slides, only. Further, staining with DAPI showed apoptotic action of bilirubin. Decreased mitochondrial function by bilirubin was observed with Mitotracker Green FM staining. These unexpected data have led us to conclude that bilirubin has anti-cancer activity as a prooxidant and may have a more vital role in the human body than realized.

Purpose: The objective of this study was to optimize the least invasive technique of radiofrequency ablation (RFA) for the degenerated renal parenchyma and to develop a novel RFA system. Materials and Methods: Tissue temperature and pathological degeneration were investigated at regular time intervals and distances from the RFA needle electrode in the renal parenchyma of the pig kidney. We also examined whether interruption of the renal artery or irrigation in the renal pelvis had an influence on the therapeutic effects. Results: Pathological investigations showed a core necrotic area surrounded by an ischemic layer around the needle electrode. Interestingly, interruption of the renal artery and irrigation in the renal pelvis markedly enhanced the degeneration of the parenchyma. Especially the electric conductivity of irrigation solutions in the renal pelvis influenced the therapeutic effect. In this novel system which retains the flow of electricity between the 2 electrodes and maintains the electric power at a constant wattage, a marked therapeutic effect was observed between the 2 electrodes rather than on their outsides, and this was not influenced by renal artery interruption and/or renal parenchyma cooling. Conclusions: This novel RFA system may contribute to more effective and highly reproducible therapeutic results.

Macrophages play a pivotal role in the development of newly formed vascular networks, in addition to their normal immunological functions. This research focuses on peritoneal macrophages as a novel source in cell implantation therapy for ischemic diseases. In this study, production of angiogenic growth factors by peritoneal macrophages and its in vivo effect of neovascularization were evaluated. Mononuclear cells from the peritoneal cavity (P-MNCs) enriched with macrophages were isolated and stimulated with hypoxia and interleukin-1beta (IL-1beta) to mimic an ischemic tissue environment in vitro. Expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) of mRNA in P-MNCs was apparently enhanced by hypoxic stimulation, and the production of VEGF protein was also augmented by hypoxia and IL-1beta. A rat ischemic hind limb model was created and P-MNCs (8 x 10(6)/limb) were injected into the ischemic muscles. The blood flow, which was assessed using the colored microsphere method, showed that the percentage blood flow was significantly increased by P-MNCs injection 4 weeks after surgery (48.3 +/- 16.8% in noninjected ischemic limb vs. 84.3 +/- 13.0% in the P-MNCs-injected limb). A histological analysis revealed that the number of capillaries detected by alkaline phosphatase staining was increased in the P-MNCs group 4 weeks after injection. Furthermore, the number of alpha-smooth muscle actin-positive vessels also showed a significant increase following P-MNC injection. The injected P-MNCs labeled with fluorescence were detected in the interstitial space of ischemic muscles, and VEGF protein expression of the implanted cells was confirmed by immunohistochemistry. These results indicate that peritoneal macrophages stimulate capillary formation and arteriogenesis in the ischemic limbs, possibly through the production of angiogenic growth factors. These findings suggest that the physiological angiogenic property of peritoneal macrophages could therefore be utilized for neovascularization in cell implantation therapy.

With the beginning of the 21st century, a new and exciting era for cancer therapy has begun with the appearance of molecular targeted drugs. Numerous drugs for chemotherapy have been discovered following careful screening of natural and synthetic components. After screening, candidate chemotherapy drugs are examined to determine if they have sufficiently cytotoxic to function as an anti-tumor therapeutic. However, the development of molecular targeted drugs is based on more logical methodologies. First, the target is determined then a search is conducted for molecules able to inhibit the target molecule. Some molecular targeting drugs, such as Glivec (Imatinib, STI571), have shown amazing effects when compared to currently used chemotherapy drugs, whereas few others have completely failed to inhibit tumor development in clinical trials. Thus, an efficient method for finding effective molecular targeted drugs is needed. An important question is whether the target molecule is responsible for tumor growth or metastasis. In addition, the clinical administration schedule must be suitable for the component used. The drugs will not be completely successful in clinical trials if any of the key points are overlooked. Translational studies are necessary for a complete evaluation of molecular targeted drugs and, based on the results observed in clinical applications, the testers must return to their basic laboratory if necessary and improve the drugs for more advanced therapy. In this review we discuss on the current and future status of molecular target drugs.

Oxidative stress generated during islet isolation and transplantation causes islet cell damage. These oxidative injuries are mediated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). MCI-186 is an antioxidant used for clinical treatment of cerebral infarction in Japan. We examined a possible protective effect of MCI-186 on islet cells against oxidative stress. Islets isolated from Sprague-Dawley rats by collagenase P digestion were purified by density gradient centrifugation with Ficoll. Islets were treated with hydrogen peroxide (H(2)O(2); 5 to 250 micromol) in the presence or absence of MCI-186. Cell death was measured by an LDH release assay. Maximum islet cell death was observed at 250 micromol of H(2)O(2). MCI-186 inhibited islet cell death in a dose-dependent manner with significant reduction above 30 micromol. From the results observed we suggest that the antioxidant effects of MCI-186 may prove beneficial to improve the preservation of islet cells.

It has been suggested that radicals stimulate tumor cell growth. We examined if the hydroxyl radical scavenger, 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), affects tumor growth in vitro.Human hepatocarcinoma HepG2, mesothelioma MSTO-211H, gastric carcinoma TMK-1 and breast carcinoma MCF-7 were used for cell proliferation assay. Cell cycle analysis was performed using propidium iodide for fluorescence activated cell sorter. By Western blotting, EGF receptor (EGFR) phosphorylation and EGFR expression were analyzed.Growth inhibition was observed from 10 microM to 300 microM of MCI-186 in a dose-dependent manner. Cell cycle analysis revealed that MCI-186 arrested the cell cycle at the G0/G1-phase. MCI-186 inhibited EGF-stimulated cell growth. The phosphorylation level of EGFR was decreased by MCI-186, but the EGFR level was unchanged.From the data obtained, we suggest that tumor inhibition by MCI-186 was due, at least in part, to the modulation of EGFR signaling and cell cycle arrest.

OG-VI, a well-balanced mixture of nucleoside and nucleotides, has been demonstrated to have a favorable effect on energy metabolism. In this study, we tested the hypothesis that addition of OG-VI to the University of Wisconsin solution can improve the cardiac functional recovery following long-time hypothermic preservation.Forty-two male Wistar rats were randomized into four groups. After 30-min of isolated working heart perfusion, the rat hearts were arrested with St. Thomas cardioplegic solution and preserved at 4 degrees C in saline, OG-VI, UW, and UW+OG-VI, respectively. After 12-h of preservation, the hearts were reperfused for 60-min during which the recovery of cardiac functions were monitored continuously. Myocardial adenine nucleotides were analyzed using high-performance liquid chromomatograph.In the UW+OG-VI group, the recovery of cardiac output, coronary flow, aortic flow, rate-pressure product, left ventricle stroke volume, and stroke work were significantly higher than other groups (P0.05). Furthermore, all phosphate high-energy compounds were significantly higher in the UW+OG-VI group than in the other groups (P0.05). Coronary vascular resistance and myocardial wet/dry weight ratio were obviously lower in the UW+OG-VI group, compared to the other groups (P0.05).Heart function was better recovered when nucleoside-nucleotide mixture was added to UW solution during long-time hypothermic rat heart preservation. The mechanism is not totally clear, but enhancement of high-energy phosphate production is possible.