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Featured researches published by Toshihide Okada.


Hepatology | 2005

Chronological development of elevated aminotransferases in a nonalcoholic population

Ayako Suzuki; Paul Angulo; James F. Lymp; Jennifer L. St. Sauver; Ayako Muto; Toshihide Okada; Keith D. Lindor

The incidence and risk factors of nonalcoholic fatty liver disease (NAFLD) have never been prospectively determined. To determine the frequency and risk factors of NAFLD and chronological ordering between NAFLD, weight gain, and features of insulin resistance, a historical cohort study was conducted in a Japanese workplace. A cohort free of previous liver injury, alcohol consumption of more than 140 g/wk, and hepatitis B or C infection (529 of 1,537 subjects), and a subcohort of 287 subjects free of insulin resistance–related features were identified. Elevated aminotransferases in nonalcoholics were used as a surrogate for NAFLD. High aminotransferases together with weight gain of more than 2 kg and insulin resistance–related features in the subcohort were sought for up to 5 years. The incidence of high aminotransferases was 31 per 1,000 person‐years (71 events). A significant interaction occurred between age and sex in the development of high aminotransferases. In subjects younger than age 40 years, male sex (hazard ratio [HR]: 4.6), elevated body mass index (HR: 2.1), hypertension (HR: 2.6), and low high‐density lipoprotein cholesterol (HR: 2.8) increased the risk of high aminotransferases, whereas age (HR: 0.6 for each 5 years) decreased the risk. In subjects older than age 40 years, glucose intolerance (HR: 5.3) was the only significant risk factor. In the subcohort, weight gain preceded high aminotransferases and other insulin resistance–related features, which appeared sequentially in order of low high‐density lipoprotein cholesterol, hypertriglyceridemia/hypertransaminasemia/hypertension, and glucose intolerance. In conclusion, this cohort study clearly showed chronological ordering and an association between development of elevated aminotransferases and risk factors of NAFLD. (HEPATOLOGY 2005;41:64–71.)


Human Mutation | 2000

Mutational analysis of ATP7B and genotype-phenotype correlation in Japanese with Wilson's disease.

Toshihide Okada; Yuta Shiono; Hisao Hayashi; Hiro Satoh; Takeshi Sawada; Ayako Suzuki; Yasuo Takeda; Motoyoshi Yano; Kojiro Michitaka; Morikazu Onji; Hiroshi Mabuchi

The gene ATP7B responsible for Wilsons disease (WD) produces a protein which is predicted to be a copper‐binding P‐type ATPase, homologous to the Menkes disease gene (ATP7A). Various mutations of ATP7B have been identified. This study aimed to detect disease‐causing mutations, to clarify their frequency and distribution, to determine whether genotype correlates with phenotype, and to determine the rate of abnormal findings in heterozygotes for the WD gene. We analyzed 41 unrelated Japanese WD families, including 47 patients. Twenty‐one mutations, including nine novel ones, were identified. 2871delC (15.9%), 1708‐5T→G (11.0%), and Arg778Leu (13.4%) were the most common mutations. 2871delC was detected mainly in eastern Japan and 1708‐5T→G in western Japan. The homozygotes for the 1708‐5T→G, 2871delC, or Arg778Leu mutations did not show a correlation with their phenotypes. Ceruloplasmin and copper levels were abnormally low in 28.6% and 35.0% of heterozygotes, respectively. When patients and their families are screened for WD, a high rate of abnormal laboratory data in heterozygotes must be taken into account. Hum Mutat 15:454–462, 2000.


The American Journal of Gastroenterology | 2001

Iron accumulation in the liver of male patients with Wilson's disease

Yuhta Shiono; Shinya Wakusawa; Hisao Hayashi; Toshikuni Takikawa; Motoyoshi Yano; Toshihide Okada; Hiroshi Mabuchi; Satoshi Kono; Hiroaki Miyajima

OBJECTIVES:There is accumulating evidence that ceruloplasmin, a copper protein with ferroxidase activity, plays an important role in iron metabolism. The genetic disorder, aceruloplasminemia, can lead to tissue storage of iron as in hemochromatosis. Because most patients with Wilsons disease, a genetic copper toxicosis, have hypoceruloplasminemia, some could be affected by iron overload.METHODS:Four male patients with Wilsons disease were enrolled in this study of pre- and post-treatment iron metabolism.RESULTS:Pretreatment copper contents of the liver were high in all four male patients studied as diagnostic of Wilsons disease. Genetic analysis supported their clinical diagnosis of Wilsons disease without a background of hemochromatosis. Pretreatment serum ceruloplasmin levels were <20 mg/dl in all four patients. A standard penicillamine treatment for 3–8.5 yr further decreased their serum ceruloplasmin levels. Post-treatment serum ferroxidase activity was low as was the serum ceruloplasmin protein. Copper contents in the liver decreased after treatment in all subjects. In contrast, nonheme iron in the liver increased during treatment. Pretreatment liver specimens were positive for histochemical iron in two patients, and post-treatment specimens were positive in all four patients. In two patients, serum aminotransferase levels rebounded with elevation of serum ferritin concentration during the treatment period. Subsequent iron reduction by phlebotomy ameliorated their biochemical liver damage.CONCLUSION:Iron overload related to hypoceruloplasminemia may be clinically important, particularly in male patients with Wilsons disease.


The American Journal of Gastroenterology | 2007

Light to Moderate Alcohol Consumption Is Associated With Lower Frequency of Hypertransaminasemia

Ayako Suzuki; Paul Angulo; Jennifer L. St. Sauver; Ayako Muto; Toshihide Okada; Keith D. Lindor

OBJECTIVES: The effect of light to moderate alcohol consumption on the liver is controversial. To determine the association between light to moderate alcohol consumption and frequency of hypertransaminasemia, a cross-sectional and a subsequent longitudinal cohort study were conducted using annual health checkup data at a Japanese workplace.METHODS: We analyzed 1,177 male subjects (age 20–59) without HCV or HBV infection or other chronic liver diseases. To determine the association between alcohol consumption (none or minimal <70 g/wk, light ≥70 g and <140 g/wk, moderate ≥140 g and <280 g/wk, excessive ≥280 g/wk) and hypertransaminasemia, we performed multiple logistic regressions. We then followed 326 subjects without a history of fatty liver or hypertransaminasemia up to 5 years for incidental hypertransaminasemia and performed Cox proportional hazard regressions.RESULTS: Excess alcohol consumption was associated with increased odds of hypertransaminasemia (adjusted odds ratio [AOR] versus none or minimal consumption 1.4[1.1–1.93], P = 0.023). There was significant interaction between age group and alcohol consumption (P < 0.01). In the younger group, moderate consumption was associated with decreased odds (AOR 0.5 [0.3–0.9], P = 0.032), while in the older group, light consumption was associated with decreased odds (AOR 0.6 [0.4–1.0], P = 0.036) and excess consumption was associated with increased odds (AOR 1.6 [1.1–2.3], P = 0.014) of hypertransaminasemia. During follow-up, moderate consumption was associated with decreased incidence of hypertransaminasemia versus none or minimal consumption (adjusted hazard ratio 0.4 [0.1–0.9], P = 0.02).CONCLUSION: Light to moderate alcohol consumption may protect against the development of hypertransaminasemia among male subjects without other liver conditions. Further studies are required before recommending light to moderate alcohol consumption.


The American Journal of Gastroenterology | 2005

Risk of colorectal neoplasm in patients with acromegaly and its relationship with serum growth hormone levels

Yutaka Matano; Toshihide Okada; Ayako Suzuki; Takashi Yoneda; Yoshiyun Takeda; Hiroshi Mabuchi

OBJECTIVES:Acromegalics have been reported to be at an increased risk of colorectal neoplasm. However, the magnitude of the risk is still controversial and the mechanism has not been fully investigated. In this study, we attempted to determine the magnitude of the association between acromegaly and colorectal lesions after taking into account age, gender, smoking status, and treatment status. In addition, we assessed the relationship between colorectal lesions and serum growth hormone (GH) levels in acromegalics.METHODS:We conducted a case–control study by using 19 consecutive untreated patients (male:female = 11:8) who were newly diagnosed with acromegaly between 1990 and 2000. All patients underwent colonoscopy and received a histological diagnosis of colorectal lesions. Prevalence of hyperplastic polyp, adenoma, and carcinoma were compared with the prevalence in 76 controls matched for gender, age, and smoking status. Serum GH levels were compared between acromegalic patients with and without each type of colorectal lesion.RESULTS:The prevalence of hyperplastic polyp, adenoma, and carcinoma were significantly higher in the acromegalic patients compared to the controls (p < 0.05, odds ratios; 8.3, 4.2, and 9.8, respectively). In acromegalics, the presence of hyperplastic polyps and carcinomas were significantly associated with higher serum GH levels after adjusting for the other lesions and age (p < 0.05).CONCLUSIONS:After controlling for age, gender, smoking status, and treatment status, acromegaly was associated with significantly higher prevalence of colorectal hyperplastic polyp, adenoma, and carcinoma. High serum GH levels may be associated with the presence of hyperplastic polyp and carcinoma.


Journal of Gastroenterology | 2010

Measurement of serum hepcidin-25 levels as a potential test for diagnosing hemochromatosis and related disorders

Yoshibumi Kaneko; Hiroaki Miyajima; Alberto Piperno; Naohisa Tomosugi; Hisao Hayashi; Natsuko Morotomi; Ken-ichi Tsuchida; Takaaki Ikeda; Akihisa Ishikawa; Yusuke Ota; Shinya Wakusawa; Kentaro Yoshioka; Satoshi Kono; Sara Pelucchi; Ai Hattori; Yasuaki Tatsumi; Toshihide Okada; Masakazu Yamagishi

BackgroundIron overload syndromes include a wide spectrum of genetic and acquired conditions. Recent studies suggest suppressed hepcidin synthesis in the liver to be the molecular basis of hemochromatosis. However, a liver with acquired iron overload synthesizes an adequate amount of hepcidin. Thus, hepcidin could function as a biochemical marker for differential diagnosis of iron overload syndromes.MethodsWe measured serum iron parameters and hepcidin-25 levels followed by sequencing HFE, HJV, HAMP, TFR2, and SLC40A1 genes in 13 Japanese patients with iron overload syndromes. In addition, we performed direct measurement of serum hepcidin-25 levels using liquid chromatography–tandem mass spectrometry in 3 Japanese patients with aceruloplasminemia and 4 Italians with HFE hemochromatosis.ResultsOne patient with HJV hemochromatosis, 2 with TFR2 hemochromatosis, and 3 with ferroportin disease were found among the 13 Japanese patients. The remaining 7 Japanese patients showed no evidence for genetic basis of iron overload syndrome. As far as the serum hepcidin-25 was concerned, seven patients with hemochromatosis and 3 with aceruloplasminemia showed markedly decreased serum hepcidin-25 levels. In contrast, 3 patients with ferroportin disease and 7 with secondary iron overload syndromes showed serum hepcidin levels parallel to their hyperferritinemia. Patients with iron overload syndromes were divided into 2 phenotypes presenting as low and high hepcidinemia. These were then associated with their genotypes.ConclusionDetermining serum hepcidin-25 levels may aid differential diagnosis of iron overload syndromes prior to genetic analysis.


Scandinavian Journal of Gastroenterology | 2010

High prevalence of fulminant hepatic failure among patients with mutant alleles for truncation of ATP7B in Wilson's disease

Toshihide Okada; Yuta Shiono; Yoshibumi Kaneko; Kazuhiro Miwa; Kenkei Hasatani; Yoshiaki Hayashi; Hiroshi Mibayashi; Hiroyuki Aoyagi; Shigetsugu Tsuji; Masashi Yoshimitsu; Hisao Hayashi; Masakazu Yamagishi

Abstract Objective. Although many mutations of the Wilsons disease (WD) gene (ATP7B) have been reported, few data exist regarding the occurrence of fulminant hepatic failure (FHF). We sought to determine if genotypic assignment according to type of protein-product could be related to the prevalence of FHF among patients with WD. Material and methods. We performed gene analysis in Japanese patients with WD as well as genotype–phenotype analysis in 51 patients. We divided genotypes into two groups according to type of ATP7B product: truncated group [T] consisted of two truncated alleles including nonsense, insertion, deletion, or splice site mutation, and missense group [M] consisted of one or two missense alleles. We also divided phenotypes into two groups: [FHF] group and [non-FHF] group. Results. We were able to determine genotype in 42 patients. Genotypically, 11 patients were assigned to [T] group and 31 to [M] group. Phenotypically, 4 patients were [FHF] and 38 were [non-FHF]. All patients in [FHF] group belonged to [T] group. The prevalence of [FHF] in [T] group was 36.4% and was significantly higher than in [M] group (p < 0.003). Conclusions. These results demonstrated that genotypes for truncation of ATP7B are associated with high prevalence of FHF.


Journal of Human Genetics | 2002

Mutational and haplotype analysis of AGL in patients with glycogen storage disease type III

Asako Horinishi; Minoru Okubo; Nelson L.S. Tang; Joannie Hui; Ka Fai To; Tomohito Mabuchi; Toshihide Okada; Hiroshi Mabuchi; Toshio Murase

AbstractGlycogen storage disease type III (GSD III) is a rare autosomal recessive inherited disorder caused by a deficiency of the glycogen-debranching enzyme (AGL). We investigated two GSD III patients and identified four different mutations. Nucleotide sequence analysis revealed patient 1 of Chinese descent to be a compound heterozygote for a novel nonsense mutation, R34X, and the splicing mutation (IVS32−12A > G) reported in a Japanese patient. Patient 2 of Japanese origin was found to be compound heterozygous for a novel nonsense mutation, Y1148X, and the splicing mutation (IVS14+1G > T) that we had described previously. To determine whether splicing mutations occurred independently, we performed intense AGL haplotype analysis using 21 intragenic polymorphic markers plus a novel polymorphism IVS32−97 A/G in the vicinity of the IVS32 splicing mutation. Patient 1 of Chinese origin and the Japanese patient homozygous for the IVS32−12A > G were found to have different haplotypes, indicating the IVS32−12A > G mutation to be a recurrent mutation. This is the first recurrent mutation established by intense haplotyping in the AGL gene.


Cancer Science | 2010

Administration route-dependent induction of antitumor immunity by interferon-alpha gene transfer.

Kenta Narumi; Atsushi Kondoh; Takeshi Udagawa; Hidehiko Hara; Naoko Goto; Yoshinori Ikarashi; Shumpei Ohnami; Toshihide Okada; Masakazu Yamagishi; Teruhiko Yoshida; Kazunori Aoki

Type I interferon (IFN) protein is a cytokine with pleiotropic biological functions that include induction of apoptosis, inhibition of angiogenesis, and immunomodulation. We have demonstrated that intratumoral injection of an IFN‐α‐expressing adenovirus effectively induces cell death of cancer cells and elicits a systemic tumor‐specific immunity in several animal models. On the other hand, reports demonstrated that an elevation of IFN in the serum following an intramuscular delivery of a vector is able to activate antitumor immunity. In this study, we compared the intratumoral and systemic routes of IFN gene transfer with regard to the effect and safety of the treatment. Intratumoral injection of an IFN‐α adenovirus effectively activated tumor‐responsive lymphocytes and caused tumor suppression not only in the gene‐transduced tumors but also in distant tumors, which was more effective than the intravenous administration of the same vector. The expression of co‐stimulatory molecules on CD11c+ cells isolated from regional lymph nodes was enhanced by IFN gene transfer into the tumors. Systemic toxicity such as an elevation of hepatic enzymes was much lower in mice treated by intratumoral gene transfer than in those treated by systemic gene transfer. Our data suggest that the intratumoral route of the IFN vector is superior to intravenous administration, due to the effective induction of antitumor immunity and the lower toxicity. (Cancer Sci 2010)


Gastrointestinal Endoscopy | 2014

Detection of pharyngeal cancer in the overall population undergoing upper GI endoscopy by using narrow-band imaging: a single-center experience, 2009–2012

Hiroyoshi Nakanishi; Hisashi Doyama; Kenichi Takemura; Naohiro Yoshida; Kunihiro Tsuji; Yasuhito Takeda; Yoshiro Asahina; Yosuke Kito; Renma Ito; Tomoyuki Hayashi; Katsura Hirano; Yoshinori Goto; Kei Tominaga; Satoko Inagaki; Yohei Waseda; Shigetsugu Tsuji; Kazuhiro Miwa; Yoshibumi Kaneko; Shinya Yamada; Hiroshi Kurumaya; Makoto Sakumoto; Toshihide Okada

BACKGROUND Nonmagnifying observation by using narrow-band imaging (NBI) is useful for detecting pharyngeal lesions. Magnifying observation by using NBI can distinguish between cancerous and noncancerous lesions and is therefore useful for the early detection of pharyngeal cancer. OBJECTIVE To evaluate the usefulness of observation of the pharynx by using NBI in the overall population undergoing upper GI endoscopy. DESIGN Retrospective study. SETTING Single tertiary referral center. PATIENTS A total of 11,050 upper GI endoscopies between January 2009 and December 2012. INTERVENTIONS Observation of the pharynx by using NBI. MAIN OUTCOME MEASURES The rate of detection of pharyngeal cancer, the rates of detection according to the reason for endoscopy, and the types of cancers detected. RESULTS Thirty-eight cancerous lesions were detected in 29 patients (0.26%, 29/11,050). The rate of detection of pharyngeal cancer was significantly higher in patients with a history of head and neck cancer (9.7%, 3/31) or a history of esophageal cancer (3.5%, 10/282). In patients undergoing endoscopy for screening, pharyngeal discomfort, and a history of gastric cancer, the rates of detection of pharyngeal cancer were 0.11% (10/8872), 1.1% (3/265), and 0.19% (3/1600), respectively. Two patients (6.9%) were female. One had a history of esophageal cancer, and the other had pharyngeal discomfort. LIMITATIONS Single-center, retrospective study. CONCLUSIONS Observation of the pharynx by using NBI in patients with previous head and neck cancer or esophageal cancer or who have pharyngeal discomfort is very important. Moreover, pharyngeal cancer was certainly found in the male patients undergoing screening endoscopy, although the rate was lower.

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Shinya Yamada

Kyoto Prefectural University of Medicine

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