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Biomedical subjects

M Iida

Publications and source records attributed to M Iida.

At least 127 records · Page 7Linked to original sources
PubMed2000

Protein expression and constitutive phosphorylation of hematopoietic transcription factors PU.1 and C/EBP beta in acute myeloid leukemia blasts.

The transcriptional activity of transcription factors is regulated by phosphorylation. The uncontrolled expression and constitutive activation of transcriptional regulators have been reported to cause malignant diseases. However, little is known about the phosphorylation status of tissue-specific transcription factors in human primary malignancies. Here we present the first insights into both protein expression and phosphorylation of transcription factors in a large-scale study of patients with acute myeloid leukemia (AML). We examined the expression and phosphorylation status of hematopoietic transcription factors PU.1 and C/EBP beta detected by the retarded mobility of the phosphorylated forms of the proteins. The rate of protein expression differed among French-American-British (FAB) subclasses. The expression of C/EBP beta and PU.1 were detectable in 77% and 61%, respectively, of 90 AML samples examined. The expressed PU.1 and C/EBP beta was always accompanied with both phosphorylated and unphosphorylated forms of PU.1 and C/EBP beta, respectively. Statistical significance was observed between PU.1 expression (phosphorylation) and FAB classification (M0, M4, or M5 versus M2 or M3, P < .0001). PU.1 and C/EBP beta were simultaneously detected in all M0, M4, M5 and peripheral blood monocytes, whereas in M2 and M3, the expression of the 2 transcription factors varied among samples. Examination of protein expression and phosphorylation of these lineage-specific molecules may help us to understand the functional characteristics of AML.

Acute Disease↗
PubMed2000

Prospective study on alcohol intake and risk of subarachnoid hemorrhage among Japanese men and women.

BACKGROUND: Few prospective data are available to evaluate potential risk factors of subarachnoid hemorrhage among the Japanese, although several prospective studies conducted in the United States and in Europe have shown a positive relationship between alcohol intake and the risk of subarachnoid hemorrhage. METHODS: A 9.4 year follow-up study was conducted on 12,372 men and women age 40 to 69 years who had no history of stroke, in six communities in Japan. The incident cases of subarachnoid hemorrhage were confirmed with computed tomography findings and/or clinical findings. Alcohol intake and other cerebrovascular risk factors were measured at the baseline examination. A Cox proportional hazard analysis was used to estimate the relative risks and 95% confidence intervals of the incidence of subarachnoid hemorrhage. RESULTS: During the follow-up assessment, 71 cases of subarachnoid hemorrhages occurred. For men, heavy drinking appeared to be an independent risk factor for subarachnoid hemorrhage; multivariate-adjusted relative risk was 4.3 (95% confidence interval [CI]: 1.1-16.8; p = 0.04). Among women, no excess risk was found for heavy drinking, probably due to the small number of heavy drinkers (n = 15). The combination of heavy drinking with smoking or hypertension increased the risk of subarachnoid hemorrhage substantially for men; the multivariate-adjusted relative risk was 6.0 (95% CI: 1.8-20.1;p = 0.004) for heavy drinking smokers and 13.0 (95% CI: 3.9-43.9; p < 0.001) for heavy drinking hypertensives. CONCLUSIONS: A reduction in alcohol intake, smoking cessation, and control of hypertension are important in preventing subarachnoid hemorrhage among Japanese men.

Adult↗
PubMed2000

Does the vertical semicircular canal influence the subjective visual vertical?

The aim of the present study is to evaluate the influence of vertical semicircular canals on the subjective visual vertical (SVV). SVV was measured on conditions with or without the rotatory stimulus in a head-tilted position, 60 deg back-ward and then rotated 45 deg either to the right or left in 7 healthy volunteers. By this procedure, it was possible to evaluate the SVV elicited by the excitability of vertical semicircular canals. SVV was normal on the condition without the rotatory stimulus. However, SVV was abnormal on the condition with the rotatory stimulus, especially, which was much deviated during the posterior canal excited. We conclude that the vertical semicircular canal influences the spatial orientation such as the SVV.

Adult↗
PubMed1999

A basic test method for the study of explosion treatment of waste chemicals from laboratories.

As a part of the research on the explosion treatment of waste chemicals from laboratories, a basic test method, which will provide the basis for our future research, was developed. First, the basic explosive, the scale of the explosion chamber and the assembly of the sample were decided. Then, measurement of detonation velocity was carried out, and the relationship between the quantity of explosive and the state of detonation propagation was obtained. A quantitative method for evaluating the decomposability of organic chemicals under explosion treatment was investigated. The results indicate that evaluating the explosion decomposability of organic chemicals from the gasification ratio could be used as a basic method provided that the excessive oxygen is approximately 62 mol% or higher. Finally, examinations of the possible effects of the quantity of explosive and conditions of atmosphere on the explosion decomposition of the model substance were conducted, and the basic test conditions regarding the quantity of explosive and condition of atmosphere were decided.

Explosions↗
PubMed1999

Depressed adenoma of the duodenum in patients with familial adenomatous polyposis: endoscopic and immunohistochemical features.

BACKGROUND: Depressed neoplastic lesions of the colorectum have been specified in patients with familial adenomatous polyposis (FAP). The aim of this study was to characterize endoscopic, histologic, and immunohistochemical features of depressed adenoma of the duodenum in patients with FAP. METHODS: Duodenoscopy was performed on 25 patients with FAP, and the neoplastic nonampullary lesions were classified as polypoid or depressed adenomas. The grade of dysplasia, the proliferative activity determined by Ki-67 labeling index (LI), and the grade of p53 expression were compared between polypoid and depressed neoplasia. RESULTS: Ten subjects had depressed nonampullary adenoma, whereas polypoid adenoma was found in the remaining 15 subjects. Moderate dysplasia was more frequent in depressed adenoma than in polypoid adenoma (70% vs. 27%, P = 0.04). Whereas p53 expression was not different between the two adenoma groups, the LI was significantly higher in depressed adenoma than in polypoid adenoma (59.7 +/- 9.5 vs. 47.5 +/- 10.7, P < 0.01). CONCLUSIONS: Depressed adenoma of the duodenum is a distinctive phenotype of duodenal neoplasm in patients with FAP. The high proliferative activity of depressed adenoma suggests that there may be a need to survey FAP patients with such lesions intensively.

Adenoma↗
PubMed1999

Dopamine D2 receptor-mediated antioxidant and neuroprotective effects of ropinirole, a dopamine agonist.

Recent information suggests that free radicals are closely involved in the pathogenesis and/or progression of Parkinson's disease (PD). High-dose levodopa therapy has been suggested to increase oxidative stress, thereby accelerating the progression of PD. Based on this viewpoint, free radical scavenging, antioxidant and neuroprotective agents which may prevent the progression of PD have recently attracted considerable attention. For example, ergot derivative dopamine (DA) agonists have been reported to scavenge free radicals in vitro and show a neuroprotective effect in vivo. Non-ergot DA agonists have also recently been used in the treatment of PD despite the lack of substantial evidence for any free radical scavenging activity or antioxidant activity. The present study was conducted to assess the in vitro free radical scavenging and antioxidant activities of ropinirole, a non-ergot DA agonist, as well as its glutathione (GSH), catalase and superoxide dismutase (SOD) activating effects and neuroprotective effect in vivo. Ropinirole scavenges free radicals and suppresses lipid peroxidation in vitro, but these activities are very weak, suggesting that the antioxidant effect of ropinirole observed in vitro may be a minor component of its neuroprotective effect in vivo. Administration of ropinirole for 7 days increased GSH, catalase and SOD activities in the striatum and protected striatal dopaminergic neurons against 6-hydroxydopamine (6-OHDA) in mice. Pre-treatment with sulpiride prevented ropinirole from enhancing striatal GSH, catalase and SOD activities and abolished the protection of dopaminergic neurons against 6-OHDA. Our findings indicate that activation of GSH, catalase and SOD mediated via DA D2 receptors may be the principal mechanism of neuroprotection by ropinirole.

Animals↗
PubMed1999

Biliary excretion of copper in LEC rat after introduction of copper transporting P-type ATPase, ATP7B.

Wilson's disease, an autosomal recessive disorder, is characterized by the excessive accumulation of hepatic copper that results from reduced biliary copper excretion and disturbed incorporation of copper into ceruloplasmin. The ATP7B gene, responsible for the disease, encodes a copper transporting P-type ATPase. We previously demonstrated the involvement of ATP7B in hepatic copper secretion into plasma after the introduction of ATP7B into the Long-Evans Cinnamon (LEC) rat, a rodent model of Wilson's disease. In this study we found the increased copper contents of the hepatic lysosomal fractions and bile in the LEC rats after ATP7B introduction, indicating the participation of ATP7B in the biliary excretory pathway for copper.

Adenosine Triphosphatases↗
PubMed1999

Trends of cardiovascular risk factors and diseases in Japan: implications for primordial prevention.

We have documented a 70% fall in stroke mortality and a 20% decline in coronary disease (CHD) mortality over the past 30 years in Japan. This parallels a change away from the traditional Japanese eating pattern, with less salt and more meat and dairy products, and decreased rates of smoking. A recent increase in CHD rates among urban Japanese men raises the need for vigorous primordial prevention efforts to avoid elevated blood lipids in modern Japanese populations, while primary prevention efforts must continue for the prevention of hypertension and smoking.

Cardiovascular Diseases↗
PubMed1999

Can quinolones cause hemorrhagic colitis of late onset? Report of three cases.

PURPOSE: This study was undertaken to demonstrate that quinolones may cause acute colitis resembling penicillin-induced hemorrhagic colitis. METHODS: We reviewed the medical records of patients with acute colitis in our institutes. Twenty-eight patients with acute hemorrhagic colitis in which no pathogenic microorganisms were identified were the subjects of this study. Pseudomembranous colitis caused by Clostridium difficile was excluded. Ulcerative colitis, Crohn's disease, and radiation proctocolitis were also excluded. RESULTS: Among these patients, 25 had a history of recent administration of penicillin derivatives. The remaining three patients had never been given any penicillin derivatives, but had ingested quinolones approximately four weeks before the developing colitis had been identified. Klebsiella oxytoca was also isolated in these three patients. CONCLUSIONS: Quinolones may cause acute hemorrhagic colitis. The time interval from antibiotic ingestion to onset of the condition may be much longer in quinolones than in penicillin derivatives.

Acute Disease↗
PubMed1999

Failure of endotoxin-free superoxide dismutase to reduce some paw edemas and adjuvant arthritis in rats.

OBJECTIVE AND DESIGN: To elucidate whether superoxide anion plays a major role in inflammation models in rats. Endotoxin-free CuZn superoxide (SOD) was used in the present study, because we had shown previously that even a trace of endotoxin contamination of SOD would carry anti-inflammatory effects. MATERIAL AND TREATMENT: Male rats were treated with saline (n=8-10), recombinant human SOD (n=8-10), and dexamethasone or indomethacin (n=8-10). METHODS: Foot volume was determined by mercury displacement. RESULTS: Two administrations of SOD (5 and 50 mg/kg), 2 h and just before irritant injection, had no effect on rat paw edema induced by phorbol, zymosan or carrageenan. Two administrations of dexamethasone (1 mg/kg) or indomethacin (3 mg/kg), 2 h and just before irritation, inhibited paw edema significantly (p<0.05). Administration of SOD (10 mg/kg) once daily for 3 weeks from the day of mycobacterium injection had no effect on injected paw swelling and non-injected paw swelling 7, 14, 21 days after irritation. Indomethacin (2 mg/kg) once daily for 3 weeks inhibited this arthritis significantly (p < 0.05). CONCLUSIONS: Superoxide anion may not play a major role in the genesis of inflammation in these rat inflammation models, and endotoxin-like contaminants may have contributed to some protective effects of SOD administration in previous studies.

Animals↗
PubMed1999

Serrated adenoma of the colorectum: colonoscopic and histologic features.

BACKGROUND: Serrated adenoma is a recently recognized epithelial neoplasm of the colorectum. The aim of this study is to clarify the colonoscopic features of serrated adenomas. METHODS: The endoscopic findings for 52 serrated adenomas of the colorectum were investigated; these were then divided into three groups according to surface features. The histologic type (tubular, tubulovillous or villous) and the incidence of high-grade dysplasia were compared among the three groups. RESULTS: The surface under chromoscopy showed a hyperplastic pattern in 17 lesions, a cerebriform pattern in 18 lesions and a combined pattern in 17 lesions. The tubular type of serrated adenoma was predominant in the hyperplastic pattern group (94%), whereas the tubulovillous or villous histologic types were frequent in the cerebriform pattern (89%) and combined pattern (82%) groups. High-grade dysplasia was found in 18% of the combined pattern adenomas; the incidence was lower in hyperplastic (6%) or cerebriform pattern (0%) adenomas. CONCLUSIONS: Surface features of serrated adenomas have a close correlation with their histologic type. A combined hyperplastic-cerebriform surface pattern under chromoscopy was seen only in serrated adenomas.

Adenoma↗
PubMed1999

Bifemelane hydrochloride protects against cytotoxicity of hydrogen peroxide on cultured rat neuroblastoma cell line.

Free radicals are involved in neuronal damage. Bifemelane hydrochloride has been reported to protect neural tissues against ischemic damage and age-related neurodegeneration. We examined the protective effects of bifemelane HCl and the relation between its effectiveness and free radical formation in hydrogen peroxide (H2O2)-induced cytotoxicity using cultured rat neuroblastoma cell line (B50). Cytotoxicity was examined by using the lactate dehydrogenase (LDH) assay and cell viability by the WST-1 assay. H2O2 reduced the survival of B50 cells in a dose-dependent manner, and treatment of these cells with 75 microM or 100 microM H2O2 reduced their viability by 50% relative to the control group. B50 cells were treated with 5 or 10 microM bifemelane for 2 days followed by treatment with 75 microM or 100 microM H2O2. H2O2 cytotoxicity was reduced by pretreatment with bifemelane. We also examined the effect of bifemelane on lipid peroxide formation in B50 cells using thiobarbituric acid reactive substances assay. Pretreatment of B50 cells with 10 microM bifemelane for 2 days reduced lipid peroxide formation to approximately 54% of the control group. Our results suggest that bifemelane hydrochloride provides a protective effect against H2O2 cytotoxicity partly due to its anti-oxidative properties.

Animals↗
PubMed1999

Lack of constitutive activation of MAP kinase pathway in human acute myeloid leukemia cells with N-Ras mutation.

Mitogen-activated protein (MAP) kinases act as transducers of extracellular signaling via tyrosine kinase-growth factor receptors and G-protein-linked receptors to transcription factors. Constitutive activation of MAP kinase has been observed in a variety of solid tumors including renal cancer and breast cancer. Recently, we have reported that constitutively activated MAP kinase was observed in 50% of human primary acute myeloid leukemia (AML) cells. Ras is one of the components of G-proteins and transduces the signal from cytokine receptors to raf-1 theoretically resulting in the activation of MAP kinase pathway. In the present study, we have examined the correlation of Ras mutations and the activation of MAP kinase pathway in patients with AML. Twenty out of 22 AML cases with activating N-Ras mutations showed no phosphorylated forms of ERK2. ERK2 phosphorylation was tightly correlated with ERK1 phosphorylation and MAP kinase activity detected by in vitro kinase assay. Three samples with N-Ras mutations were stimulated with IL-3, GM-CSF and G-CSF separately but ERK2 activation was induced in none of these samples stimulated with these cytokines. In contrast, ERK2 was constitutively activated in all of four pancreatic carcinoma cases with K-Ras mutation at codon 12. These results suggest that function of the Ras mutations may be different between solid tumors, such as pancreatic carcinoma and colorectal carcinoma, and AML. Mutated Ras does not always stimulate MAP kinase pathway constitutively and may rather inhibit classical MAP kinase cascade in AML blasts from leukemia patients.

Acute Disease↗