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Useful Clues (useful + clue)
Selected AbstractsOmnidirectional Vision and Inertial Clues for Robot NavigationJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1 2004Irem Stratmann The structural features inherent in the visual motion field of a mobile robot contain useful clues about its navigation. The combination of these visual clues and additional inertial sensor information may allow reliable detection of the navigation direction for a mobile robot and also the independent motion that might be present in the 3D scene. The motion field, which is the 2D projection of the 3D scene variations induced by the camera-robot system, is estimated through optical flow calculations. The singular points of the global optical flow field of omnidirectional image sequences indicate the translational direction of the robot as well as the deviation from its planned path. It is also possible to detect motion patterns of near obstacles or independently moving objects of the scene. In this paper, we introduce the analysis of the intrinsic features of the omnidirectional motion fields, in combination with gyroscopical information, and give some examples of this preliminary analysis. © 2004 Wiley Periodicals, Inc. [source] Anti-cancer activity of anti-p185HER-2 ricin A chain immunotoxin on gastric cancer cellsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2010Xin-Xin Zhou Abstract Background and Aim:, Overexpression of the human epidermal growth factor receptor 2 (HER-2) protein has been detected in gastric cancer and has been associated with an unfavorable prognosis. We investigated the anti-cancer effects of anti-p185HER-2 ricin A chain (RTA) immunotoxin, alone or in combination with 5-flurouracil on SGC7901-HER-2+ cells. Methods:, SGC7901-HER-2+ cells were obtained by transfecting SGC7901 cells with HER-2-pcDNA3.1. Anti-p185HER-2 -RTA was prepared by chemical conjugation of anti-HER-2 monoclonal antibody (mAb) and RTA. The SGC7901-HER-2+ cells were incubated with RTA, anti-p185HER-2 -RTA, and/or 5-flurouracil. The effects of drugs on cells were evaluated by MTT assay and Annexin V-fluorescein isothiocyanate and propidium iodide double staining flow cytometry. The expression of caspase-3, caspase-9, cyclooxygenase-2, and nuclear factor-,B/p65 were assayed by western blot. SGC7901-HER-2+ cells were transplanted into BALB/c nude mice to produce solid tumors in an attempt to study the immunotoxin activity in vivo. Results:,In vitro, anti-p185HER-2 -RTA inhibited cell growth and induced apoptosis in SGC7901-HER-2+ cells. Anti-p185HER-2 -RTA enhanced caspase-3 and caspase-9 activity, while downregulating the expression of cyclooxygenase-2 and nuclear factor-,B/p65. Its combination with 5-flurouracil further inhibited the growth of SGC7901-HER-2+ cells. In vivo, our data showed that anti-p185HER-2 -RTA significantly inhibited the growth of SGC7901-HER-2+ cells-transplanted tumors. Conclusions:, Anti-p185HER-2 -RTA inhibits the growth of SGC7901-HER-2+ cells. The effect may be related to the activation of caspase-3 and caspase-9 and inhibition of cyclooxygenase-2 and nuclear factor-,B/p65. Anti-p185HER-2 -RTA plus 5-FU enhance anti-cancer activity, suggesting useful clues for further study for the treatment of HER-2 positive gastric cancers. [source] Stability and hydrolysis kinetics of spirosuccinimide type inhibitors of aldose reductase in aqueous solution and retardation of their hydrolysis by the target enzymeJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2008Masuo Kurono Abstract The stability and the hydrolysis kinetics of spirosuccinimide type aldose reductase (AR) inhibitors, SX-3030 (racemate) and its optical enantiomers (R - and S -isomers), were investigated in aqueous solution. The hydrolysis followed pseudo-first-order kinetics and showed significant pH dependence. Maximum solution stability was observed below pH 2.4, whereas the hydrolysis was gradually catalyzed by hydroxide ion at neutral to alkaline pH while the compounds exhibiting moderate pH-independent stability at acidic to neutral conditions (pH 4,7) to enable oral administration. A pK of 3.7 was obtained from the pH-rate profile, but this kinetically derived pK is approximately 2 pH units below the pK of the parent compounds, suggesting the presence of an acidic intermediate involved in the hydrolysis process. These findings, together with structural analysis, support the notion that the hydrolysis would proceed via nucleophilic attack of a water molecule or hydroxide ion on the scissile carbonyl bond of the succinimide ring to form a succinamic acid intermediate that has a ,-keto acid structure, followed by decarboxylation to give a racemized succinimide ring-opened product. On the other hand, the interconversion of the R - and S -isomers did not occur during hydrolysis; however, the hydrolysis of the R -isomer was markedly suppressed by the target enzyme AR whereas that of the S -isomer was not, indicating a high degree of complementarity of interacting surfaces between the R -isomer and the enzyme. The results in the present study could provide useful clues for facilitating the appropriate stabilization strategies as well as for evaluating the pharmacological effects on target tissues in vivo, and suggested that the R -isomer may be a suitable candidate as AR inhibitor. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:1468,1483, 2008 [source] Arteriolar Involvement in the Microvascular Lesions of Diabetic Retinopathy: Implications for PathogenesisMICROCIRCULATION, Issue 1 2007TOM A. GARDINER ABSTRACT Diabetic retinopathy (DR) is the most widespread complication of diabetes mellitus and a major cause of blindness in the working population of developed countries. The clinicopathology of the diabetic retina has been extensively studied, although the relative contribution of the various biochemical and molecular sequelae of hyperglycemia remains ill defined. Many neural and microvascular abnormalities occur in the retina of short-term diabetic animals but it remains uncertain how closely these acute changes relate to chronic human disease. It is important to determine the relationship between alterations observed within the first weeks or months in short-term animal models, and human disease, where clinically manifest retinopathy occurs only after durations of diabetes measured in years. This review is focused on the retinal microvasculature, although it should be appreciated that pathological changes in this system often occur in parallel with abnormalities in the neural parenchyma that may be derivative or even causal. Nevertheless, it is useful to reevaluate the microvascular lesions that are manifest in the retina during diabetes in humans and long-term animal models, since in addition to providing useful clues to the pathogenic basis of DR as a disease entity, it is in the deterrence of such changes that the efficacy of any novel treatment regimes will be measured. In particular, an emphasis will be placed on the relatively unappreciated role of arteriolar dysfunction in the clinical manifestations and pathology of this disease. [source] | ||||||||||