Hirotaka Nishisako

The University of Tokushima, Tokusima, Tokushima, Japan

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Publications (6)9.12 Total impact

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    ABSTRACT: AimVinorelbine is an anticancer drug associated with vascular injury. The mechanism of vascular injury is associated with the decrease of endothelial nitric oxide synthase (eNOS), which regulates oxidative stress. Kakkonto, a traditional Japanese medicine, has anti-inflammatory and anti-oxidative effects. We evaluated the effect of kakkonto on vinorelbine-induced vascular injury and its mechanism of action.Methods Human umbilical vein endothelial cells were used as the endothelial model. We compared vinorelbine-induced cytotoxicity after pre-incubation with the seven kakkonto components using ATP assay. Mitochondrial membrane potential was assessed using Mitochondrial Membrane Potential Assay Kit. Intracellular calcium ion concentration ([Ca2+]i) was measured with a calcium-sensitive dye, Fluo-4 AM. eNOS and Akt phosphorylation after ephedra extract or vinorelbine treatment were investigated on western blot.ResultsEphedra, a kakkonto component, protected cells against vinorelbine-induced cytotoxicity. Ephedra extract preserved eNOS phosphorylation by increasing [Ca2+]i, but it had no effect on Akt phosphorylation. The increase in [Ca2+]i was mediated by Ca2+ influx via l-type calcium channels. Additionally, inhibition of Ca2+ influx or eNOS phosphorylation abolished the effects of ephedra extract.Conclusion Ephedra extract preserved eNOS phosphorylation following vinorelbine-induced oxidative stress, thereby protecting cells from vinorelbine-induced cytotoxicity. Moreover, the protective effect of ephedra extract is dependent on the increase of [Ca2+]i and the Ca2+/calmodulin-dependent signal transduction pathway.
    07/2015; DOI:10.1002/tkm2.1024
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    ABSTRACT: Drug-induced interstitial lung disease (DILD) is generally a serious adverse effect and almost always necessitates the discontinuation of the offending drug. Cancer pharmacotherapy is strongly associated with DILD, and the risk of DILD has been suggested to be higher in patients with lung cancer because of preexisting pneumonic disease. The aim of this retrospective study was to identify the risk factors and prognostic factors for early death from interstitial lung disease (ILD) induced by chemotherapy for lung cancer. The medical records of 459 patients who underwent chemotherapy for lung cancer between April 2007 and March 2013 were analyzed with regard to patient background and DILD development, initial symptoms, and prognosis. A total of 33 patients (7.2%) developed chemotherapy-induced ILD. The most frequently observed initial symptom was dyspnea (94.3%). Preexisting ILD was identified as a risk factor for DILD (odds ratio [OR] = 5.38; 95% CI = 2.47-11.73; P < 0.01). Among the 33 patients who developed DILD, 10 patients suffered an early death despite steroid therapy. Poor prognostic factors included epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) use (OR = 9.26; 95% CI = 1.05-82.0; P < 0.05) and 2 or more prior chemotherapy regimens (OR = 6.95; 95% CI = 1.14-42.3; P < 0.05). Many lung cancer patients have coexisting ILD, and these patients have a high risk of developing chemotherapy-induced ILD. In addition, patients with DILD who underwent EGFR-TKI therapy and 2 or more prior chemotherapy regimens had a higher risk of fatal outcome. © The Author(s) 2015.
    Annals of Pharmacotherapy 01/2015; 49(4). DOI:10.1177/1060028014566446 · 2.06 Impact Factor
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    ABSTRACT: Effects of a time-varying magnetic field on cell volume regulation by hyposmotic stress in cultured bovine adrenal chromaffin cells were examined. Through regulatory volume decrease (RVD), cell volume of chromaffin cells that were incubated in a hypotonic medium initially increased, reached a peak and finally recovered to the initial value. Two hour exposure to a magnetic field and addition of cytochalasin D increased peak value and delayed return to initial value. Intracellular F-actin contents initially decreased but returned to normal levels after 10 sec. Two hour exposure to the magnetic field and addition of cytochalasin D continuously reduced the F-actin content. Results suggest that exposure to the magnetic field stimulated disruption of the actin cytoskeleton and that the disruption delayed the recovery to the volume prior to osmotic stress.
    The Journal of Medical Investigation 02/2011; 58(1-2):95-105. DOI:10.2152/jmi.58.95
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    ABSTRACT: Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF) for treatment of metastatic colorectal cancer. Recently, much evidence has suggested that bevacizumab-induced hypertension might be predictive of the effect of bevacizumab. The aim of our study is to retrospectively assess the relationship between the onset of hypertension and the activity of bevacizumab in Japanese metastatic colorectal cancer patients. Between July 2007 and December 2010, 36 patients (median age 66 years; 36-81 years) with metastatic colorectal cancer were assigned to receive bevacizumab in combination with either mFOLFOX6 (5-FU, levofolinate and oxaliplatin) or FOLFIRI (5-FU, levofolinate and irinotecan) at the Tokushima University Hospital. A patient who had increase by >20 mmHg in diastolic blood pressure or had increase to >150/100 mmHg or received antihypertensive treatment was defined as hypertensive. The objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) were compared between the hypertensive group (n=10) and non-hypertensive group (n=26). ORR and DCR were 60.0% and 100%, respectively, in the hypertensive group and ORR and DCR were 23.1% and 80.8%, respectively, in the non-hypertensive group. These differences were statistically significant (p<0.05). The median PFS tended to be longer in the hypertensive group (65.0 weeks) than in the non-hypertensive group (40.0 weeks). Our data suggested that bevacizumab-induced hypertension may be predictive of the effect of bevacizumab in Japanese metastatic colorectal cancer patients.
    YAKUGAKU ZASSHI 01/2011; 131(8):1251-7. DOI:10.1248/yakushi.131.1251 · 0.26 Impact Factor
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    ABSTRACT: It has been reported that exposure to electromagnetic fields influences intracellular signal transduction. We studied the effects of exposure to a time-varying 1.5 T magnetic field on membrane properties, membrane cation transport and intracellular Ca(2+) mobilization in relation to signals. We also studied the mechanism of the effect of exposure to the magnetic field on intracellular Ca(2+) release from Ca(2+) stores in adrenal chromaffin cells. We measured the physiological functions of ER, actin protein, and mitochondria with respect to a neurotransmitter-induced increase in Ca(2+) in chromaffin cells exposed to the time-varying 1.5 T magnetic field for 2h. Exposure to the magnetic field significantly reduced the increase in [Ca(2+)]i. The exposure depolarized the mitochondria membrane and lowered oxygen uptake, but did not reduce the intracellular ATP content. Magnetic field-exposure caused a morphological change in intracellular F-actin. F-actin in exposed cells seemed to be less dense than in control cells, but the decrease was smaller than that in cytochalasin D-treated cells. The increase in G-actin (i.e., the decrease in F-actin) due to exposure was recovered by jasplakinolide, but inhibition of Ca(2+) release by the exposure was unaffected. These results suggest that the magnetic field-exposure influenced both the ER and mitochondria, but the inhibition of Ca(2+) release from ER was not due to mitochondria inhibition. The effect of eddy currents induced in the culture medium may indirectly influence intracellular actin and suppress the transient increase in [Ca(2+)]i.
    Biochimica et Biophysica Acta 12/2010; 1800(12):1221-30. DOI:10.1016/j.bbagen.2010.09.001 · 4.66 Impact Factor
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    ABSTRACT: A novel product, 4-amino-5-guanidinopentanoic acid 15-[(4-aminobutyl)-3-aminopropylcarbamoyl] pentadecyl ester (Arg-HSA-Spm), was synthesized based on ptilomycalin A, which is one of the extracts from marine sponge. Arg-HSA-Spm contains arginine in its chemical structure. The pharmacological action of Arg-HSA-Spm on catecholamine secretion from cultured bovine adrenal chromaffin cells was examined. Arg-HSA-Spm inhibited catecholamine secretion stimulated by the physiological secretagog acetylcholine. This inhibitory action of Arg-HSA-Spm on catecholamine secretion induced by 10(-4) M acetylcholine was dose-dependent from 10(-8) M to 10(-5) M. In the presence of 3 x 10(-7) M Arg-HSA-Spm, the stimulation of catecholamine secretion observed by increasing acetylcholine up to 10(-3) M did not reach the maximal level observed without Arg-HSA-Spm. Arg-HSA-Spm at 10(-5) M suppressed both the increase in intracellular free Ca2+ level and the influx of 45Ca2+ induced by 10(-4) M acetylcholine. The Arg-HSA-Spm-induced suppression of intracellular free Ca2+ level, the influx of 45Ca2+ and catecholamine secretion were not observed in the presence of extracellular K+ at 56 mM. The results presented in this study suggested that Arg-HSA-Spm may inhibit the influx of extracellular Ca2+ into the cells, probably through its blocking action related to acetylcholine receptors, resulting in the inhibition of catecholamine secretion in adrenal chromaffin cells.
    Journal of Cardiovascular Pharmacology 01/2004; 42 Suppl 1:S15-8. DOI:10.1097/00005344-200312001-00005 · 2.14 Impact Factor