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Dive into the research topics where Misako Okita is active.

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Featured researches published by Misako Okita.


Nutrition | 2001

Effect of a Moderately Energy-Restricted Diet on Obese Patients With Fatty Liver

Misako Okita; Mayumi Hayashi; Takayo Sasagawa; Koji Takagi; Kazuhiko Suzuki; Shingo Kinoyama; Toshio Ito; Gotaro Yamada

The effects of a moderately energy-restricted (25 kcal/kg) diet on liver-function tests, anthropometric measurements, mononuclear-cell phospholipid fatty acid, lymphocyte blastogenesis, and plasma prostaglandin E2 and alpha-tocopherol levels were observed at weeks 0, 8, and 24 in 14 obese patients with fatty liver. Serum aminotransferase levels were improved significantly, with decreases in the body mass index and waist circumference. Decreases in energy intake from carbohydrate and increases in intake of vitamin A, vitamin C, and vegetables were observed at week 24. In mononuclear-cell phospholipids, linoleic acid (18:2omega 6), which was significantly lower in patients than in controls at week 0, was increased at week 24. In contrast, arachidonic acid was decreased. Plasma prostaglandin E2 levels were significantly lower in patients than in controls at week 0 and increased at week 24. The mononuclear-cell response for phytohemagglutinin correlated with 18:2omega 6 in mononuclear-cell phospholipids (r = 0.692, P < 0.01). Improvement of the serum alanine-aminotransferase level correlated with an increase in the plasma alpha-tocopherol level (r = -0.667, P < 0.01) and increases in consumption of vitamin A, omega 3 polyunsaturated fatty acids, and vegetables. These findings suggest that a hypoenergetic diet rich in omega 3 polyunsaturated fatty acids and antioxidants might be beneficial for obese patients with fatty liver.


Lipids | 1999

Abnormal serum lysophospholipids in multiple myeloma patients

Takayo Sasagawa; Misako Okita; Jun Murakami; Tsutomu Kato; Akiharu Watanabe

Lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA) mediate various kinds of biological activities and play an important role in cellular signal transduction. We analyzed serum phospholipids obtained from 16 multiple myeloma (MM) patients and observed that serum LPA level was significantly higher in MM patients (5.3±0.5 nmol/mL) than in normal controls (1.7±0.3 nmol/mL). LPC level was also higher than that in normal controls, and it correlated significantly with the concentration of LPA (r=0.678, P<0.01). In MM patients, palmitic acid/linoleic acid ratios in phosphatidylcholine and LPC were higher than those in normal controls. In the 12-mon follow-up study of two patients with the immune globulin G type, we recognized that the increase of LPC, LPA, and arachidonic acid/linoleic acid ratio in phosphatidylinositol corresponded with a decline in the serum albumin level and choline esterase activity.


Free Radical Research | 2003

Effect of Vitamin E on Serum Aminotransferase and Thioredoxin Levels in Patients with Viral Hepatitis C

Sabina Mahmood; Gotaro Yamada; Gouichi Niiyama; Miwa Kawanaka; Kazumi Togawa; Miho Sho; Toshio Ito; Takayo Sasagawa; Misako Okita; Hajime Nakamura; Junji Yodoi

Objectives: Oxidative stress induces cellular responses such as cell death, gene activation and cell proliferation, in the liver. Vitamin E (Vit. E) has been found to protect the liver against oxidative stress in animal experiments. Thioredoxin (TRX) is a stress inducible, multifunctional protein, secreted during oxidative stress. This study evaluated effects of Vit. E on serum TRX and aminotransferase levels in hepatitis C virus (HCV) patients, partly non-responsive to initial interferon (IFN), with higher than average level of serum alanine aminotransferase (ALT) after receiving anti-inflammatory drug treatment. Methods: Seventeen HCV patients (male=3; female=14) of age 62±7.65 years receiving anti-inflammatory drug therapy, at least 6 months prior to Vit. E administration, were given d-α´-tocopherol 500 mg/day, orally, for a period of 3 months. ALT, aspartate aminotransferase (AST), TRX and Vit. E were measured at 0, 1, 2 and 3 months and 1 month after end of treatment. As controls, the same patients biochemical data, 3 months from the start of therapy were used. Patients were divided into three categories: total patients “T”, low ALT group “L” (ALT<70 IU/l) and high ALT group “H”(ALT>70 IU/l), respectively.Results: The ALT level was lowered, significantly in group H, in the 1st, 2nd, 3rd and 1-month post therapy, compared to the initial value. But group L showed little or no change in ALT. Post Vit. E therapy, in groups T and H, the TRX level was elevated but remained below initial levels, whereas in group L, TRX level remained significantly lower than the pretreatment value. Groups T and L, showed significant reduction (p<0.05) in serum TRX levels in the 2nd and 3rd month. Group H showed a tendency towards TRX reduction, but not significantly. Serum Vit. E levels increased significantly (p<0.0001) from the 1st to 3rd month in all three T, H and L groups. Conclusion: Oxidative stress induced liver damage is reduced by Vit. E in patients with viral hepatitis C, particularly those with initial ALT levels >70 IU/l. Vit. E treatment causes reduction of oxidative stress markers as TRX and ALT in sera. Therefore, Vit. E can act as a supportive therapy to combat liver damage caused by oxidative stress, in such patients with continuously high levels of ALT even after anti-viral and anti-inflammatory drug therapy.


Nutrition | 2002

Habitual food intake and polyunsaturated fatty acid deficiency in liver cirrhosis.

Misako Okita; Takayo Sasagawa; Kayoko Tomioka; Kaori Hasuda; Yasuko Ota; Kazuhiko Suzuki; Akiharu Watanabe

OBJECTIVE We compared the habitual food intake and plasma fatty acid composition in cirrhotic patients living in two different regions in Japan, Okayama and Toyama, and evaluated the effects of dietary polyunsaturated fatty acid and alpha-tocopherol intake on serum alanine aminotransferase (ALT) activity. METHOD A quantitative food-frequency questionnaire method was used. RESULTS The significantly higher intake of fish in the patients living in Toyama resulted in higher plasma levels of docosahexaenoic acid and lower levels of arachidonic acid. Serum ALT activity correlated negatively with plasma arachidonic acid (r = -0.456, P < 0.05) and alpha-tocopherol (r = -0.505, P < 0.05) levels. Dietary intakes of vitamin E and polyunsaturated fatty acids (mg/g) correlated negatively with serum ALT (r = -0.377, P < 0.05). Dietary intake of linoleic acid and the ratio of polyunsaturated to saturated fatty acid in dietary fat correlated significantly with serum ALT (r = 0.604, P < 0.01, and r = 0.622, P < 0.01, respectively). The amount of vegetable intake correlated with intake of vitamin E and polyunsaturated fatty acid (r = 0.527, P < 0.02). CONCLUSIONS These findings suggest that habitual food intake affects the plasma fatty acid profile and that elevated serum ALT may be related to arachidonic acid deficiency and vulnerability to lipid peroxidation in cirrhotic patients with hepatitis B and C viruses.


Journal of Gastroenterology and Hepatology | 2006

417–2α-Tocopherol and ascorbic acid attenuates the ribavirin-induced decrease of eicosapentaenoic acid in erythrocyte membrane in chronic hepatitis C patients

Keisuke Hino; Yasuko Murakami; Ayako Nagai; Akira Kitase; Yuichi Hara; Takakazu Furutani; Fenyu Ren; Yuhki Yamaguchi; Kohki Yutoku; Satoyoshi Yamashita; Michiari Okuda; Misako Okita; Kiwamu Okita

Background:  Oxidative damage of the erythrocyte membrane plays an important role in ribavirin‐induced anemia. The purpose of the present paper was to assess whether supplementation of α‐tocopherol and ascorbic acid (vitamins) causes changes in the erythrocyte membrane fatty acid composition during interferon and ribavirin combination therapy for chronic hepatitis C patients.


Nutrition | 1999

Low plasma levels of docosahexaenoic acid in patients with liver cirrhosis and its correction with a polyunsaturated fatty acid–enriched soft oil capsule

Akiharu Watanabe; Seiji Saito; Toshihiro Tsuchida; Kiyohiro Higuchi; Misako Okita

Plasma levels of docosahexaenoic acid (DHA, C22:6 omega 3) were found to be decreased in 11 patients with alcoholic and non-alcoholic liver cirrhosis depending on the severity of liver damage. In this reduction, we found impaired metabolism of omega-3 long-chain polyunsaturated fatty acids in the cirrhotic liver and poor dietary intake of DHA to involved in the reduction of DHA plasma levels. The deficiency of this fatty acid, which is concentrated in the nervous tissues, may be related to the impaired neural function observed in hepatic encephalopathy of these patients. Oral DHA supplementation was supplied in the form of a polyunsaturated fatty acid-enriched soft oil capsule (omega 3/omega 6 ratio = 0.91, and P/S ratio = 1.87). Twelve capsules per day (containing 408 mg DHA, which corresponds to one-fourth of the DHA content in a normal daily diet) improved the DHA contents in the plasma phospholipid fractions of 5 alcoholic patients with low DHA levels.


Nutrition | 2003

Arachidonic acid in mononuclear cells and its clinical significance in HCV cirrhotic patients.

Misako Okita; Kayoko Tomioka; Yasuko Ota; Takayo Sasagawa; Toshiya Osawa; Nobuyuki Sakai; Mitsuhiko Kawaguchi; Tatsuya Itoshima

OBJECTIVES An abnormal fatty acid pattern in patients with advanced liver cirrhosis (LC) has been reported in plasma phospholipids and some other tissues. To elucidate the significance of arachidonic acid deficiency on the clinical pathophysiology of LC and hepatocellular carcinoma (HCC), we analyzed the fatty acid compositions of mononuclear cell phospholipids, plasma alpha-tocopherol, and thiobarbituric acid-reactive substances and serum tumor necrosis factor-alpha (TNF-alpha) in cirrhotic patients infected with the hepatitis C virus with and without HCC. METHODS Twelve cirrhotic patients without HCC (LC patients) and 11 with HCC (HCC patients) were enrolled. Fatty acids were analyzed with gas chromatography. alpha-Tocopherol and TNF-alpha were analyzed by high-performance liquid chromatography and enzyme-linked immunosorbent assay, respectively. Statistical analysis was performed by using the unpaired t test with Welchs correction and Spearmans rank-correlation analysis. RESULTS Significantly low levels of linoleic, dihomo-gamma-linolenic, arachidonic, and eicosapentaenoic acids from mononuclear cell phospholipids were observed in LC and HCC patients compared with control subjects. Plasma alpha-tocopherol was lower and thiobarbituric acid-reactive substances were higher in HCC patients than in controls. Arachidonic acid molar percentage in mononuclear cell phospholipids correlated significantly with lymphocyte count (r = 0.460, P < 0.05) in the cirrhotic patients and with lymphocyte (r = 0.680, P < 0.01) and platelet (r = 0.763, P < 0.01) counts in all subjects. CONCLUSIONS These results suggested that arachidonic acid in mononuclear cells may have an important role in the pathophysiology of hepatitis C virus associated with cirrhosis and that nutritional management preventing arachidonic acid deficiency may have some beneficial effects on the progression of LC.


Biochimica et Biophysica Acta | 1999

Analysis of the fatty acid components in a perchloric acid-soluble protein.

Takayo Sasagawa; Tatsuzo Oka; Akira Tokumura; Yuriko Nishimoto; Saturnino Muñoz; Masashi Kuwahata; Misako Okita; Hideaki Tsuji; Yasuo Natori

We had previously found that a perchloric acid-soluble protein (PSP1) occurs in rat liver, and that this novel protein inhibits protein synthesis in a rabbit reticulocyte lysate system (T. Oka, H. Tsuji, C. Noda, K. Sakai, Y.-H. Hong, I. Suzuki, S. Muñoz, Y. Natori, J. Biol. Chem. 270 (1995) 30060-30067). In the present study, we analyzed lipid components bound to PSP1. Native PSP1 was purified from rat liver using Sephadex G-75, DE-52 cellulose and IgGPSP-affinity chromatography, and the lipid components were extracted. The components obtained from the purified PSP1 were shown to be free fatty acids by thin-layer chromatography. By GC-MS, six major fatty acids were identified as 14:0, 16:0, 18:0, 18:1, 18:2 and 20:4. 1 mol of PSP1 contained 1.26 mol of total fatty acid components. The fatty acid-binding assay of PSP1 showed that the Bmax was 1.25 mol fatty acid/mol PSP1 and the Kd value for palmitic acid was 6.03 microM. The concentration of PSP1 mRNA in rat liver increased 2.3-fold by the administration of peroxisome proliferator, bezafibrate. These findings show that PSP1 is a fatty acid-binding protein-like protein, which is involved in the intracellular metabolism of fatty acid and is quite different from the known fatty acid-binding proteins.


Biochimica et Biophysica Acta | 1998

Epitope mapping of monoclonal antibodies against 4-aminobenzoate hydroxylase from Agaricus bisporus

Hideaki Tsuji; Masumi Kimoto; Hiroyuki Watanabe; Takayo Sasagawa; Tatsuzo Oka; Hiromi Yamashita; Misako Okita

Four monoclonal antibodies (mAbs) against 4-aminobenzoate hydroxylase (EC 1.14.13.27) have been produced (H. Tsuji et al., J. Biol. Chem. 265 (1990) 16064; T. Ogawa et al., Biochim. Biophys. Acta 1115 (1992) 220). Of the mAbs, three mAbs (mAb-A, -B1 and -B2) recognize the FAD-binding domain of the enzyme. In the present study, the epitopes of the mAbs on the enzyme have been examined using pGEX-2T expression systems for DNA fragments encoding various partial amino acid sequences of 4-aminobenzoate hydroxylase. The epitopes for mAb-A, -B1 and -B2 were shown to be on sequences 413-434, 435-460 and 380-413, respectively. These findings suggest that these epitopes for mAb-A, -B1 and -B2 may be close to the isoalloxazine moiety of FAD, which plays a central role in the catalysis of the enzyme.


Archive | 2013

Dietary Fatty Acids and Alcoholic Liver Disease

Takayo Kawakami; Yasuko Murakami; Misako Okita

Alcoholic liver disease (ALD), such as fatty liver, hepatitis, or fibrosis, is frequently observed in patients with a long history of excessive alcohol intake. These types of ALD are considered alcohol-associated lifestyle diseases and involve both genetic and environmental factors [1]. Interactions between alcohol and nutritional status, which are one of the secondary risk factors, may also be important. Indeed, the presence and extent of protein-calorie malnutrition have important roles in determining the outcome of patients with ALD. Micronutrient abnormalities, such as hepatic vitamin A depletion or depressed vitamin E levels, may also potentially aggravate liver disease [2]. Additionally, obesity and excess body weight have been associated with an increased risk of ALD [3, 4]. Alcoholic and nonalcoholic fatty liver each begin with the accumulation of lipids in the liver, which, although a reversible condition, is understood to play an important role in the development of advanced liver disease. With continued alcohol intake, the development of steatosis may progress to hepatitis and fibrosis and might lead to liver cirrhosis. Excessive alcohol intake adversely influences the liver through the production of toxic products such as acetaldehyde and potentially highly reactive oxygen molecules, which are generated by alcohol dehydrogenase and the microsomal ethanol oxidizing system. These products can directly and indirectly interfere with the normal metabolism of other nutrients, particularly lipids, contributing to liver cell damage [5].

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Takayo Sasagawa

Okayama Prefectural University

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Kazuhiko Suzuki

Okayama Prefectural University

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Hideaki Tsuji

Okayama Prefectural University

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Hiromi Yamashita

Okayama Prefectural University

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Akiharu Watanabe

Kawasaki University of Medical Welfare

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Masumi Kimoto

Okayama Prefectural University

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Takayo Kawakami

Okayama Prefectural University

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Yasuko Ota

Okayama Prefectural University

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Ayako Nagai

Okayama Prefectural University

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