The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Willy Malaisse - One of the best experts on this subject based on the ideXlab platform.
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effects of <B>CytochalasinB> B and d upon insulin release and pancreatic islet cell metaBolism
International Journal of Molecular Medicine, 2002Co-Authors: Hassan Jijakli, Abdullah Sener, Haixia Zhang, Eszter Dura, Remedios Ramirez, Willy MalaisseAbstract:<B>CytochalasinB> B is known to enhance insulin release evoked By nutrient and non-nutrient secretagogues, including D-glucose, despite inhiBiting D-glucose uptake and metaBolism in pancreatic islets. In the present study, <B>CytochalasinB> D, which failed to affect D-glucose uptake and metaBolism By isolated islets, also augmented glucose-stimulated insulin release, But unexpectedly to a lesser extent than <B>CytochalasinB> B. Such was not the case, however, in islets stimulated By non-glucidic nutrients such as 2-ketoisocaproate or the association of L-leucine and L-glutamine. This situation coincided with the fact that <B>CytochalasinB> B inhiBited more severely D-glucose metaBolism in non-B, as distinct from B, islet cells and, in the former case, caused a relatively greater inhiBition of hexose cataBolism at 2.8 mM than at 16.7 mM D-glucose. Nevertheless, even in the presence of forskolin, <B>CytochalasinB> B was more efficient than <B>CytochalasinB> D in augmenting glucose-stimulated insulin secretion. Thus, although these data document that non-B islet cells are more sensitive than purified islet B cells to <B>CytochalasinB> B, at least in terms of inhiBition of D-glucose cataBolism, such a difference and its possiBle consequence upon the release of glucagon and other non-insulinic hormones By non-B islet cells do not appear sufficient to account for the greater enhancing action of <B>CytochalasinB> B, as distinct from <B>CytochalasinB> D, upon glucose-stimulated insulin output. Likewise, the latter difference does not appear attriButaBle to a greater efficiency of <B>CytochalasinB> B, as compared to <B>CytochalasinB> D, upon the mechanical events involved in nutrient-stimulated exocytosis of insulin granules. Hence, the present findings suggest a so-far-unidentified interference of <B>CytochalasinB> B with the B-cell glucose-sensing device.
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Binding of [3H]<B>CytochalasinB> B to tumoral islet cells.
Biochemistry international, 1990Co-Authors: S Garcia-mateu, Manuela Barreto, Isabel Valverde, Willy MalaisseAbstract:: Tumoral pancreatic islet cells of the RINm5F line are equipped with two classes of [3H]<B>CytochalasinB> B Binding sites with respective Kd of 0.4 and 7 microM. The Binding of the fungal metaBolite and its dissociation from the Binding sites display rapid time courses. The Binding is inhiBited By D-glucose, more than By L-glucose, By phlorizin and By <B>CytochalasinB> E. These findings are considered in the light of the dual action of <B>CytochalasinB> B upon hexose transport and motile activity in islet cells.
Hideyo Yabu - One of the best experts on this subject based on the ideXlab platform.
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effect of <B>CytochalasinB> B on intestinal smooth muscle cells
European Journal of Pharmacology, 1994Co-Authors: Kazuo Obara, Hideyo YabuAbstract:ABstract The inhiBitory effect of <B>CytochalasinB> B on contraction of smooth muscle cells isolated from guinea-pig taenia coli was investigated. <B>CytochalasinB> B (10–70 μM) inhiBited the high K + (70 mM)-induced contraction in a dose-dependent manner, and the maximum and the half-maximum effects were oBtained at 50 and 15 μM, respectively. <B>CytochalasinB> B (70 μM) decreased ATPase activity in skinned guinea-pig taenia coli. However, <B>CytochalasinB> B (50 μM) had no significant effect on the voltage-dependent Ca 2+ currents, the passive memBrane properties or the memBrane potential. <B>CytochalasinB> B also had no effect on the phosphorylation of 20 kDa myosin light chain induced By high K + and cytosolic Ca 2+ levels. These results suggest that the inhiBition of contraction By <B>CytochalasinB> B may Be due to its effects on actin of microfilaments and contractile filaments of guinea-pig taenia coli smooth muscle cells.
Hassan Jijakli - One of the best experts on this subject based on the ideXlab platform.
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effects of <B>CytochalasinB> B and d upon insulin release and pancreatic islet cell metaBolism
International Journal of Molecular Medicine, 2002Co-Authors: Hassan Jijakli, Abdullah Sener, Haixia Zhang, Eszter Dura, Remedios Ramirez, Willy MalaisseAbstract:<B>CytochalasinB> B is known to enhance insulin release evoked By nutrient and non-nutrient secretagogues, including D-glucose, despite inhiBiting D-glucose uptake and metaBolism in pancreatic islets. In the present study, <B>CytochalasinB> D, which failed to affect D-glucose uptake and metaBolism By isolated islets, also augmented glucose-stimulated insulin release, But unexpectedly to a lesser extent than <B>CytochalasinB> B. Such was not the case, however, in islets stimulated By non-glucidic nutrients such as 2-ketoisocaproate or the association of L-leucine and L-glutamine. This situation coincided with the fact that <B>CytochalasinB> B inhiBited more severely D-glucose metaBolism in non-B, as distinct from B, islet cells and, in the former case, caused a relatively greater inhiBition of hexose cataBolism at 2.8 mM than at 16.7 mM D-glucose. Nevertheless, even in the presence of forskolin, <B>CytochalasinB> B was more efficient than <B>CytochalasinB> D in augmenting glucose-stimulated insulin secretion. Thus, although these data document that non-B islet cells are more sensitive than purified islet B cells to <B>CytochalasinB> B, at least in terms of inhiBition of D-glucose cataBolism, such a difference and its possiBle consequence upon the release of glucagon and other non-insulinic hormones By non-B islet cells do not appear sufficient to account for the greater enhancing action of <B>CytochalasinB> B, as distinct from <B>CytochalasinB> D, upon glucose-stimulated insulin output. Likewise, the latter difference does not appear attriButaBle to a greater efficiency of <B>CytochalasinB> B, as compared to <B>CytochalasinB> D, upon the mechanical events involved in nutrient-stimulated exocytosis of insulin granules. Hence, the present findings suggest a so-far-unidentified interference of <B>CytochalasinB> B with the B-cell glucose-sensing device.
Thomas P Fondy - One of the best experts on this subject based on the ideXlab platform.
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preparation in vivo administration dose limiting toxicities and antineoplastic activity of <B>CytochalasinB> B
Translational Oncology, 2015Co-Authors: Matthew Trendowski, Joseph N Zoino, Timothy D Christen, Christopher Acquafondata, Thomas P FondyAbstract:An effective and inexpensive protocol for producing <B>CytochalasinB>s A and B is Being disclosed to propose a viaBle method By which to examine the in vivo antineoplastic activity of these congeners in preclinical tumor-Bearing mammalian models. In addition, we determine the maximum tolerated doses of <B>CytochalasinB> B using multiple routes and formulations, characterize the tissue distriBution of intravenous Bolus <B>CytochalasinB> B, and assess the in vivo antineoplastic activity of <B>CytochalasinB> B in comparison in doxoruBicin in BalB/c mice challenged intradermally with M109 murine lung carcinoma. We also examine the effects of <B>CytochalasinB> B against several other murine neoplastic cell lines (Lewis lung, LA4, B16F10, and M5076). Finally, we examine a potential mechanism of the antimetastatic activity of <B>CytochalasinB> B By oBserving the effects of the agent on the secretion of N-acetylglucosaminidase (GlcNACase) By B16BL6 and B16F10 murine melanomas in vitro. The results of the study can Be summarized as follows: 1) <B>CytochalasinB> B can Be safely administered intravenously, intraperitoneally, and suBcutaneously in murine models, with the maximum tolerated dose of all routes of administration Being increased By liposome encapsulation. 2) <B>CytochalasinB> B can significantly inhiBit the growth of tumors in mice challenged with M109, Lewis lung, LA4, B16F10, or M5076, producing long-term survival against lung carcinomas and adenocarcinomas (M109, Lewis lung, and LA4) and B16F10 melanoma, But not M5076 sarcoma. These effects were comparaBle to intraperitoneally administered doxoruBicin. 4) Low concentrations of <B>CytochalasinB> B inhiBit the secretion of GlcNACase, indicating that <B>CytochalasinB> B may inhiBit metastatic progression By mechanisms not directly associated with its influence on cell adhesion and motility.
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Chemotherapy in vivo against M109 murine lung carcinoma with <B>CytochalasinB> B By localized, systemic, and liposomal administration
Investigational New Drugs, 2015Co-Authors: Matthew Trendowski, Christopher Acquafondata, Joan M. Mitchell, Christine M. Corsette, Thomas P FondyAbstract:<B>CytochalasinB> B is a potentially novel microfilament-directed chemotherapeutic agent that prevents actin polymerization, thereBy inhiBiting cytokinesis. Although <B>CytochalasinB> B has Been extensively studied in vitro, only limited data are availaBle to assess its in vivo potential. <B>CytochalasinB> B was administered to BalB/c mice challenged i.d. with M109 murine lung carcinoma to determine whether the agent could affect an estaBlished i.d. tumor when the compound is administered s.c. in the region of the i.d. tumor, But not in direct contact with it. <B>CytochalasinB> B was also administered either i.p. or s.c. at a distant site or i.v. to determine whether it could affect the long-term development of an estaBlished i.d. tumor. <B>CytochalasinB> B was then liposome encapsulated to determine whether the maximum tolerated dose (MTD) of the compound could Be increased, while reducing immunosuppression that we have previously characterized. Liposomal <B>CytochalasinB> B was also administered to mice challenged i.d. with M109 lung carcinoma to assess its chemotherapeutic efficacy. The results can Be summarized as follows: 1) <B>CytochalasinB> B suBstantially delayed the growth of i.d. M109 tumor nodules, inhiBited metastatic progression in surrounding tissues, and produced long-term cures in treated mice; 2) liposomal <B>CytochalasinB> B increased the i.p. MTD By more than 3-fold, produced a different distriBution in tissue concentrations, and displayed antitumor effects against M109 lung carcinoma similar to non-encapsulated <B>CytochalasinB> B. These data show that <B>CytochalasinB> B exploits unique chemotherapeutic mechanisms and is an effective antineoplastic agent in vivo in pre-clinical models, either in Bolus form or after liposome encapsulation.
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the real deal using <B>CytochalasinB> B in sonodynamic therapy to preferentially damage leukemia cells
Anticancer Research, 2014Co-Authors: Matthew Trendowski, Timothy D Christen, Christopher Acquafondata, Guowu Yu, Victoria Wong, Thomas P FondyAbstract:Background/Aim: Sonodynamic therapy (SDT) is a form of ultrasound therapy in which chemotherapeutic agents known as sonosensitizers are administered to increase the efficacy of ultrasound's preferential damage to neoplastic cells. Perhaps one of the most intriguing capaBilities of ultrasound is its aBility to preferentially lyse cells Based on size. <B>CytochalasinB> B is a cytokinesis inhiBitor that preferentially enlarges and multinucleates malignant cells, making them much more sensitive to ultrasonic irradiation. Materials and Methods: The present study investigated the extent of preferential damage inflicted By <B>CytochalasinB> B on U937 leukemia/human Blood cell populations. Cell mixtures were treated with <B>CytochalasinB> B and then sonicated under a relatively low intensity (3W/cm2). Results: <B>CytochalasinB> B preferentially damages U937 cells Both Before and after sonication. This agent also reduces rapid proliferation as the clonogenicity of U937 cells was consideraBly reduced following treatment. Conclusion: <B>CytochalasinB> B may have profound therapeutic applications when comBined with SDT.
Kazuo Obara - One of the best experts on this subject based on the ideXlab platform.
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effect of <B>CytochalasinB> B on intestinal smooth muscle cells
European Journal of Pharmacology, 1994Co-Authors: Kazuo Obara, Hideyo YabuAbstract:ABstract The inhiBitory effect of <B>CytochalasinB> B on contraction of smooth muscle cells isolated from guinea-pig taenia coli was investigated. <B>CytochalasinB> B (10–70 μM) inhiBited the high K + (70 mM)-induced contraction in a dose-dependent manner, and the maximum and the half-maximum effects were oBtained at 50 and 15 μM, respectively. <B>CytochalasinB> B (70 μM) decreased ATPase activity in skinned guinea-pig taenia coli. However, <B>CytochalasinB> B (50 μM) had no significant effect on the voltage-dependent Ca 2+ currents, the passive memBrane properties or the memBrane potential. <B>CytochalasinB> B also had no effect on the phosphorylation of 20 kDa myosin light chain induced By high K + and cytosolic Ca 2+ levels. These results suggest that the inhiBition of contraction By <B>CytochalasinB> B may Be due to its effects on actin of microfilaments and contractile filaments of guinea-pig taenia coli smooth muscle cells.
