Publications by authors named "Onosaka S"

In the point dose verification of intensity-modulated radiation therapy (IMRT), we compared the commonly used method of measuring absolute dose (absolute method) with the measurement method by the American Association of Physicists in Medicine Task Group 119, which describes the point dose verification for IMRT using the ratio of reference irradiation and measured ionization. The target was 66 plans for head and neck cancer, 46 plans for lung cancer with 6 MV X-ray, and 31 plans for prostate cancer with 10 MV X-ray. They were treated with volumetric-modulated arc therapy (VMAT).

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In high-dose-rate brachytherapy, the geometry of the radioactive source is sometimes updated. Some institutions use a different source model for the dose calculation in treatment planning and treatment. The effects of this discrepancy were examined for four types of treatment plans, and ten patients were selected for each treatment plan.

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A wide range of medications are routinely used to maintain and improve human health. Hence, it is essential that we understand and predict adverse effects caused by the combined use of multiple medications. In the present study, we investigated whether the combination of carbon tetrachloride (CCl) and acetaminophen (APAP) had a detrimental effect on the liver.

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The aim of this study was to determine whether calcium potentiates acute carbon tetrachloride (CCl4) -induced toxicity. Elevated calcium levels were induced in mice by pre-treatment with cholecalciferol (vitamin D3; V.D3), a compound that has previously been shown to induce hypercalcemia in human and animal models.

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Objective: The aim of this study was to investigate whether pretreatment with the Japanese herbal medicine "Hochu-ekki-to" (TJ-41) has an ameliorative effect on carbon tetrachloride (CCl)-induced hepatotoxicity through anorexia prevention.

Methods: Twenty-four hours before CCl injection, TJ-41 or saline solution was intraperitoneally administered. Furthermore, 24 h after TJ-41 injection, mice were intraperitoneally administered 1.

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The aim of the present study was to investigate whether pretreatment with the Japanese herbal medicine, "Juzen-taiho-to" (JTX), had an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.

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The aim of this study is to investigate whether a Ca-deficient diet has an attenuating effect on carbon tetrachloride (CCl4)-induced hepatotoxicity. Four-week-old male ddY mice were fed a Ca-deficient diet for 4 weeks as a part of the experimental protocol. While hypocalcemia was observed, there was no significant change in body weight.

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In the current study, we evaluated the protective effect of zinc (Zn) against bromobenzene (BB) -induced lethal toxicity. We used Zn because this element is known to be an inducer of metallothionein (MT), which is in turn known to serve as an endogenous scavenger of free radicals. We administered Zn (as ZnSO4) at 50 mg/kg subcutaneously once-daily for 3 successive days prior to a single intraperitoneal administration of 1.

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Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. In addition, many studies showed that CCl4 can induce kidney damage. In the current study, we evaluated the protective effect of zinc (Zn) against CCl4-induced nephrotoxicity.

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Carbon tetrachloride (CCl4) is commonly used as a chemical inducer of experimental liver injury. Several compounds have been demonstrated to attenuate the hepatic damage caused by sublethal doses of CCl4. However, rescue from lethal toxicity of CCl4 has not been reported.

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Abnormal iron (Fe) metabolism induces iron-deficiency anemia (FeDA) and also affects body cadmium (Cd) accumulation. However, whether hemolytic anemia also affects Cd metabolism is not known. We compared the intestinal absorption and tissue accumulation of Cd after oral administration of Cd to mice with hemolytic anemia induced by treatment with phenylhydrazine (PHA mice) to that in mice with FeDA.

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Metallothionein (MT) is involved not only in heavy metal homeostasis/detoxification but also in radical scavenging, yet the relevance to other antioxidant systems and physiological significance under oxidative stress has not been clarified. We studied that ability of MT, induced by zinc and cadmium, to protect against oxidative damage induced by ferric nitrilotriacetate (Fe-NTA) in glutathione depleted primary cell cultures. Treatment with Fe-NTA resulted in significant decreases in cell survival and increases in medium LDH activity in control cells following depletion of glutathione.

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Metallothionein (MT) demonstrates strong antioxidant properties, yet the physiological relevance of its antioxidant action is not clear. Injection of mice with ferric nitrilotriacetate (Fe-NTA) caused a dose-dependent increase in hepatic and renal MT. Fe-NTA caused a greater increase in hepatic and renal MT concentration (2.

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Cadmium is known to be a potent carcinogenic and mutagenic metal. However, we demonstrated that dietary supplementation with 50 ppm cadmium inhibits spontaneous carcinogenesis in C3H/HeN and spontaneous hepatitis in A/J mice. We found that the frequencies of spontaneous hepatocarcinogenesis in C3H/HeN mice and of spontaneous hepatitis in A/J mice fed low-dose cadmium for 54 weeks were significantly lower than those in the respective control groups.

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Zinc (Zn) is an essential, common metal in animal tissues. Zn levels were elevated in only four tissues after Zn administration, the highest increase being in the pancreas. Zn concentration was increased by metallothionein induction.

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Article Synopsis
  • Several compounds, including cadmium (Cd), can cause acute toxicity, and glucocorticoids like dexamethasone can influence tolerance to this toxicity through mechanisms involving metallothionein (MT) synthesis.
  • In an experiment with mice, those induced with inflammation (Tur-mice) showed a higher tolerance (higher LD50) to Cd than control mice, but pretreatment with dexamethasone led to reduced tolerance and increased liver enzyme levels in response to Cd.
  • The study indicates that glucocorticoids may suppress the protective effects of inflammation on Cd toxicity, suggesting that inflammatory cytokines like IL-6 play a significant role in modulating Cd toxicity through MT synthesis.
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Metallothionein (MT) is a strong antioxidant, due to a large number of thiol groups in the MT molecule and MT has been found in the nucleus. To investigate whether MT can directly protect DNA from damage induced by hydroxyl radical, the effects of MTs on DNA strand scission due to incubation with ferric ion-nitrilotriacetic acid and H2O2 (Fe3+ -NTA/H2O2) were studied. The Fe3+-NTA/H2O2 resulted in a higher rate of deoxyribose degradation, compared to incubation of Fe3+/H2O2, presumably mediated by the formation of hydroxyl radicals (*OH).

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Rats fed a Zn-deficient diet develop a characteristic cyclic variation in feed intake (Mills et al., Am J Clin Nutr 22: 1240-1249 (1969). A preliminary analysis (Tamaki et al.

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Subcutaneous injection of colchicine caused dose-dependent and time-dependent induction of hepatic MT in mice. Other than colchicine, similar MT induction was observed in vincristine- or vinblastine-injected mice, but not in beta-lumicolchicine-injected mice. MT contents were also elevated in the kidney, spleen, lung and heart by colchicine injection.

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Cadmium-metallothionein (Cd-MT) is selectively distributed to the kidney, producing nephropathy similar to that seen following chronic exposure to Cd. The critical concentration of Cd after an injection of Cd-MT (about 10 micrograms/g) is much lower than that following chronic Cd exposure (130-200 micrograms/g). To investigate whether administration of Cd-MT at nonacute toxic dosages can induce chronic nephrotoxicity similar to inorganic Cd, i.

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The toxicological significance of the placental metallothionein (MT) was studied from the viewpoint of cadmium (Cd) intoxication. The Cd concentration was higher in the placenta than the kidneys until 8 hr after a single injection of 109CdCl2, but was very low after administration of 109Cd-MT. Compared with lower doses, fetal Cd began to increase at the dose of 2 mg/kg.

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The effects of erythropoiesis on cadmium-metallothionein (Cd-MT)2 levels in spleen, a major erythropoietic tissue, was examined following sc injection of 109CdCl2 into mice. As the concentration of Cd in plasma decreased following injection of 109CdCl2 into control mice, the levels in spleen and liver increased rapidly. After 48 hr, when the concentration of Cd in the erythrocyte (RBC) was at maximum, the level of Cd in the spleen, but not liver, had decreased.

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The body weight and feed intake of rats fed on a Zn-deficient diet for 28 d were reduced compared with those of control rats. The feed intakes of the Zn-deficient and control groups during the period were 10.2 (SE 0.

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The mechanism of metallothionein (MT) synthesis in the liver by n-hexane (HX) was examined. The increased synthesis of MT in the liver by HX was inhibited by dexamethasone pretreatment. Serum IL-6 was increased soon after HX injection, reaching a maximum at 8-16 hr, and then decreased, but neither IL-1 nor TNF was increased.

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The fate cadmium(Cd) bound to phytochelatin [PC, (gamma-Glu-Cys)n-Gly)] was studied in rats using synthesized 109Cd-PC. Less Cd was absorbed through the digestive tracts than CdCl2, but the ratio of renal Cd to hepatic Cd was higher. After parenteral administration of Cd-PC, Cd was distributed mainly in the liver, kidney, small intestine and pancreas.

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