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Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 469 records · Page 26Linked to original sources
PubMed1998

Combined use of bacteriophage typing and pulsed-field gel electrophoresis in the epidemiological analysis of Japanese isolates of enterohemorrhagic Escherichia coli O157:H7.

A total of 236 enterohemorrhagic Escherichia coli (EHEC) O157:H7 isolates in Japan were investigated by bacteriophage typing, and the results were compared with those of pulsed-field gel electrophoresis (PFGE). Seven phage types (PTs) were observed in 71 isolates which were derived from 22 outbreaks. All of the isolates from ten outbreaks in the Kinki region (midwestern part of Japan) in July-August 1996 were grouped into the same PFGE type (IIa) and PT 32, while among total isolates, there were such varieties as PFGE type IIa containing five phage types and PT32 containing two PFGE types. These results suggest that the ten outbreaks should be considered to be a single outbreak, and show that the combined use of bacteriophage typing and PFGE enhances reliability in epidemiological surveys.

Bacteremia↗
PubMed1998

Expression of the SART-1 antigens in uterine cancers.

We recently reported that the SART-1 gene, encoding the SART-1(259) tumor antigen which is recognized by HLA-A26-restricted cytotoxic T lymphocytes (CTLs), is expressed in the cytosol of squamous cell carcinomas and adenocarcinomas. The present study deals with the expression of SART-1(259) and SART-1(800) antigens in uterine cancers. The SART-1(259) antigen was detected in the cytosol fraction of 4 of 8 uterine cancer cell lines, 24 of 74 (32%) uterine cancer tissues, 0 of 7 uterine myomas, and 0 of 5 non-tumorous uterine tissues. The SART-1(800) antigen was expressed in the nuclear fraction of all the uterine cancer cell lines, 41 of 74 (55%) uterine cancer tissues, 0 of 7 myomas, and 3 of 5 non-tumorous uterine tissues. The SART-1(259)+ uterine cancer cells were recognized by HLA-A24 restricted and SART-1 specific CTLs. Therefore, SART-1(259) antigen could be an appropriate vaccine candidate for a relatively large number of uterine cancer patients.

Adenocarcinoma↗
PubMed1998

Sequence analysis of genes encoding rodent homologues of the human tumor-rejection antigen SART-1.

Human SART-1 (hSART-1) gene encodes a 125 kD protein with a leucine-zipper motif expressed in the nucleus of all proliferating cells, and a 43 kD protein expressed in the cytosol of most epithelial cancers. In this study, two rodent genes (rSART-1 and mSART-1) homologous to hSART-1 were cloned from cDNA libraries of murine brain and a rat tumor cell line, respectively. mSART-1 and rSART-1 were highly homologous to hSART-1 with 86% and 84% identity at the nucleotide level, and 95% and 91% at the protein level, respectively. The leucine zipper domain and two basic amino acid portions that bind DNA, as well as peptide sequences recognized by human cytotoxic T lymphocytes (CTLs), were all conserved in these rodent genes. Nuclear protein homologous to the 125 kD hSART-1(800) protein, but not to the 43 kD cytosol SART-1(259) protein, was detectable with specific antibody in the nuclear fractions of rodent tumor cell lines, and normal rodent fetal liver and testis. These rodent genes should be a novel tool for studies on the biological roles of the SART-1 gene, and also in the construction of animal models of specific immunotherapy using SART-1 gene products.

Amino Acid Sequence↗
PubMed1998

Polymorphism of the 5'-flanking region of the human tumor necrosis factor (TNF)-alpha gene in Japanese.

Polymorphism of the 5'-flanking promoter/enhancer region of the TNF-alpha gene in Japanese is not well understood. To better understand it, we have determined the 1,358 base pair sequence of the 5'-flanking region of the TNF-alpha gene in nine Japanese, and identified three new polymorphisms at positions 1,031 (T to C change, termed as -1,031C), -863 (C to A, -863A), and -857 (C to T, -857T), with the former two in one allele. The level of TNF-alpha production by concanavalin A (Con A)-activated peripheral blood mononuclear cells from the five donors possessing at least one new allele was 1.8-fold higher than that from the remaining four donors with the dominant allele. The transcriptional promoter activity of the 1,031C/-863A or -857T allele in response to Con A stimulation was 2.0 or 1.7-fold higher than that of the dominant allele, respectively. The allele frequencies of -1,031C, -863A, -857T, -308A (G to A), and -238A (G to A) (the latter two were previously reported) in 575 healthy Japanese were 16.0, 14.0, 17.7, 1.7 and 2.0%, respectively. The -1,031C/-863A or -857T allele was in significant linkage disequilibrium with HLA-B61, -B39 and -DRB1*0901, or with HLA-B54, -B35, -B59, and -DRB1*0405, respectively. The newly identified alleles observed in a relatively large proportion of Japanese may be related to differences in levels of TNF-alpha production in immune responses to various stimuli among individuals.

Alleles↗
PubMed1998

Patient background of the Pokemon phenomenon: questionnaire studies in multiple pediatric clinics.

Many children in Japan developed various neuropsychological problems, including seizures, while watching the program Pocket Monster, televised on 16 December 1997. To examine the basis for this incident, we have performed a survey of volunteering children and their parents who visited our pediatric clinics for other reasons from 8 January to 28 February 1998. Children and their parents filled out questionnaires. Among the total of 662 children surveyed, the great majority (603, 91.1%) was found to have watched the Pocket Monster program and 30 individuals (5.0% of viewers) complained of variable degrees of neuropsychological abnormalities. These included seizures (two cases), headache (nine cases), nausea (eight cases), blurred vision (four cases), vertigo (two cases), dysthymia (two cases) and vomiting (one case). Nearly half (14) of these children developed symptoms during or immediately after watching the program, while the remainder did so later. Representative cases are reported and other statistical aspects are discussed.

Adolescent↗
PubMed1998

Portal vein anomaly associated with deviation of the ligamentum teres to the right and malposition of the gallbladder.

PURPOSE: To develop a complete clinical picture of a portal vein anomaly associated with a rightward-deviated ligamentum teres. MATERIALS AND METHODS: Three hundred twenty-seven consecutive living donor candidates for partial liver transplantation were evaluated for hepatic vascular abnormalities with computed tomography supplemented with intraoperative examinations. Special attention was given to the branching pattern of the portal system and the relative positions of the umbilical portion of the portal vein, the ligamentum teres, and the gallbladder. RESULTS: Four donor candidates (1.2%) had a portal vein anomaly associated with a rightward-deviated ligamentum teres. In all four, the umbilical portion of the portal vein (and hence the ligamentum teres) was abnormal, lying above the gallbladder bed and giving off major branches to the right anterior segment. If unrecognized, these might have been ligated, leading to major complications in the donors. CONCLUSION: A portal vein anomaly associated with a rightward-deviated ligamentum teres is an important clinical entity that is not as rare as indicated in the literature. This anomaly should be kept in mind during preoperative examination of the liver.

Adult↗
PubMed1998

Histological evaluation of the effects of electropermeabilization after administration of bleomycin on bladder cancer in the rat.

OBJECTIVE: The aim of this study was to examine the usefulness of an electropermeabilization method in the administration of a chemotherapeutic agent in bladder cancer in the rat. MATERIALS AND METHODS: N-Butyl-N-(4-hydroxybutyl)-nitrosamine was used to induce bladder tumors in Wistar rats. Rats in group 1 were given a sham treatment. Rats in group 2 received an injection of bleomycin (BLM). Rats in group 3 received a series of eight 100- micros square-wave pulses at an electric field intensity of 1,000 V/cm (electropermeabilization) applied to the bladder. Rats in group 4 were treated with square-wave pulses after the injection of BLM. Nine days after the various treatments, all the bladders were removed and examined histopathologically. RESULTS: Histopathological examination revealed severe damage to tumors in group 4 exclusively. CONCLUSION: The cytotoxic effect of BLM on bladder cancer tissue was enhanced by electropermeabilization.

Animals↗
PubMed1998

Enzymatic peptide synthesis with p-guanidinophenyl and p-(guanidinomethyl)phenyl esters as acyl donors.

Two series of "inverse substrates", N-Boc-amino acid p-guanidinophenyl and p-(guanidinomethyl)phenyl esters, were prepared as acyl donor components for enzymatic peptide synthesis. The kinetic behavior of these esters toward bovine and Streptomyces griseus (SG) trypsin was analyzed. The spatial requirement of the active site of these enzymes for catalytic efficiency is discussed based on the steric characteristics of the substrates. These substrates were found to couple readily with amino acid p-nitroanilides to produce peptides. SG trypsin was the most efficient catalyst among the enzymes tested (bovine, porcine, and SG trypsin).

Acylation↗
PubMed1998

A case report of myolysis during high-dose amiodarone therapy for uncontrolled ventricular tachycardia.

We report a rare case of a 41-year-old male patient, a professional musician, with dilated cardiomyopathy and sustained ventricular tachycardia (VT) that was refractory to class I antiarrhythmic drugs. Severe myolysis developed after 10 months' administration of amiodarone (400 mg/day) in combination with mexiletine (300 mg/day) and disopyramide (400 mg/day). He had been suffering from severe moving muscle pain and an extremely high (16,830) IU/ml) serum level of creatine kinase (CK). The dosage of amiodarone was reduced from 400 mg/day to 200 mg/day without reduction of mexiletine or disopyramide and the patient's symptoms diminished. However, sustained VT developed, and so the dosage of the drug was increased to 250 mg/day. The high serum level of CK also decreased and returned to the normal range after the reduction in amiodarone dosage. Electrophysiologic examination of moving muscle revealed normal motor and sensory conduction velocities and, furthermore, the electromyogram revealed normal potentials and normal motor units. We conclude that severe myolysis developed as a result of the high dose and chronic administration of amiodarone. This is the first report of a Japanese patient showing rare and serious adverse effects in response to amiodarone treatment.

Adult↗
PubMed1998

Cytotoxicity induced by Erythrina variegata serine proteinase inhibitors in tumor hematopoietic stem cell lines.

Based on the soluble MTT tetrazolium/formazan assay, we evaluated the cytotoxicity of Erythrina variegata proteinase inhibitors in some tumor hematopoietic stem cell lines. Among the proteinase inhibitors, EBI, which belongs to the Bowman-Birk family of inhibitors, was cytotoxic in relatively differentiated cells such as Molt4 and Jurkat derived from acute T lymphoblastic leukemia (T-ALL) cells specifically, but ETIa and ECI, which are classified into Kunitz family inhibitors, did not. It was suggested that the differences in the cytotoxicity might be due to the molecular size of the inhibitors. The succinylation of lysine residue(s) of EBI led to about 50% loss of the trypsin inhibitory activity as compared with the authentic EBI. When Molt4 cells were incubated with this derivative, no significant cytotoxicity was observed. This suggests that the proteinase inhibitory activity might be involved in the cytotoxicity in human tumor cell lines.

Cell Survival↗
PubMed1998

Reduction in blood pressure with a sodium-reduced, potassium- and magnesium-enriched mineral salt in subjects with mild essential hypertension.

A parallel controlled clinical trial was carried out to investigate the effect on blood pressure (BP) of replacing normal salt with mineral salt in seasonings. After a 2-wk run-in period, 21 subjects (10 men and 11 women; age, 66.0+/-7.6 yr) were given mineral salt in seasonings instead of normal salt [mineral salt (MS) group], while 20 subjects (10 men and 10 women; age, 65.9+/-7.4 yr) continued to receive normal salt in seasonings [regular salt (RS) group] for the next 5 wk in the experimental (E) period. In the MS group, systolic (S) and diastolic (D) BP decreased significantly from 134.7+/-17.2/77.2+/-9.7 at baseline (week 0) to 127.3+/-12.0/73.5+/-8.9 mmHg at the end of the E period (week 5), and the reductions in both SBP and DBP were larger in hypertensive subjects than in normotensive subjects in the MS group. The serum sodium and chloride concentrations decreased significantly, while the serum potassium and HDL-cholesterol concentrations increased significantly at week 5. The 24-h urinary sodium excretion decreased, and the 24-h potassium and magnesium excretions increased significantly from week 0 to week 5 in the MS group. In contrast, SBP, DBP, serum chemistry, and urinary electrolyte excretion did not change significantly in the RS group. These findings suggest that the excessive salt content and insufficient potassium and magnesium content of the present Japanese diet could be easily and safely corrected by replacing seasonings prepared with regular salt with those prepared with mineral salt.

Aged↗
PubMed1998

Effect of mouse intestinal bacteria on incidence of colorectal tumors induced by 1,2-dimethylhydrazine injection in gnotobiotic transgenic mice harboring human prototype c-Ha-ras genes.

We produced transgenic (Tg) gnotobiotic (GB) mice carrying human prototype c-Ha-ras genes and compared the incidence of colorectal tumors induced by 1,2-dimethylhydrazine (DMH) injection. At 7 to 11 weeks of age, germfree (GF) CB6F1-Tg Hras2 mice were inoculated with various mouse fecal suspensions or mixtures of bacteria isolated from mouse feces. Three weeks after bacterial inoculation, DMH was administered by subcutaneous injection at 20 mg per kg body weight for 20 weeks. Mice were euthanized 5 weeks after the last injection to investigate the number of colorectal tumors. The incidence of colorectal tumors was high in both Tg- and non-Tg-GF mice (100%). In Tg-specific pathogen-free (SPF) mice and Tg-GB-4 mice associated with basic mouse flora consisting of Escherichia coli, lactobacilli, Bacteroides and clostridia, the incidence of colorectal tumors was as high as that in GF mice. In Tg-SPF mice, the tumor score was higher than in Tg-GF mice (p < 0.01), but no colorectal tumors were detected in non-Tg groups of SPF, and the tumor incidence was remarkably low in non-Tg-GB-4 mice. The tumor incidence and score in Tg- and non-Tg-GB mice varied depending on the bacterial combination in their intestine. These results indicate that the presence of human c-Ha-ras genes and intestinal bacteria substantially modify colorectal tumorigenesis induced by DMH.

1,2-Dimethylhydrazine↗
PubMed1998

Left postpneumonectomy syndrome successfully treated with endobronchial stent.

We describe a case of left pneumothorax-induced left postpneumonectomy syndrome in the absence of anatomical anomalies developing at 10 years after the operation. We placed an endobronchial stent into the right truncus intermidius and the procedure resulted in recovery of the syndrome. We consider endobronchial stent placement as an effective treatment for postpneumonectomy syndrome, especially when surgical management is not feasible.

Aged↗
PubMed1998

[Two cases of Churg-Strauss syndrome with impaired prognosis].

We report two cases of Churg-Strauss syndrome with impaired prognosis. Case 1: A 58-year-old woman started to complain of progressive dysesthesia and muscle weakness of the lower extremities on February 6, 1992 and was admitted to our hospital eight days later. The eosinophil count was 1, 170/microliters and chest X-ray on admission revealed bilateral diffuse interstitial shadows. Necrosis of muscle fibers and significant infiltration of eosinophils into vessel walls were histopathologically demonstrated. Case 2: A 69-year-old woman was admitted to our hospital with productive cough and back pain. An expiratory wheeze was audible in all lung fields and bronchial asthma was diagnosed. Laboratory findings showed eosinophilia (8, 550/microliters), an IgE level of 16, 266 IU/ml and no positive data for allergic bronchopulmonary aspergillosis. A biopsy of subcutaneous nodules in the lower extremity revealed significant edema of vessel walls and infiltration eosinophils and lymphocytes. Churg-Strauss syndrome was diagnosed in both cases, and corticosteroid therapy was successful in alleviating eosinophilia. However, symptoms of vasculitis in case 1, including mononeuritis multiplex, did not improve, and cardiomyopathy in case 2 progressively worsened. Particularly in elderly patients, it is very important to make an early diagnosis and to initiate therapy that does not disturb quality of life, even for diseases generally regarded as having a good or fair prognosis.

Aged↗
PubMed1998

Variable expression on lung cancer cell lines of HLA-A2-binding MAGE-3 peptide recognized by cytotoxic T lymphocytes.

Cytotoxic T lymphocytes (CTL) specific for HLA-A2-binding MAGE-3 peptide (FLWGPRALV) were generated by repetitive stimulation of PBMC with the peptide in the presence of EBV-transformed B blasts and IL-2. Using these CTL, we investigated the expression of the HLA-A2-binding MAGE-3 peptide on lung cancer cell lines. Of 14 cell lines investigated, 1-87, PC-9, OU-LC-KI, 11-18 and LK87 were derived from HLA-A2 positive patients. But cytofluorometry analysis showed that 1-87, PC-9 and OU-LC-KI, but not 11-18 or LK87 expressed the HLA-A2 antigen. All five cell lines expressed MAGE-3 gene mRNA. Twelve of thirteen CTL lines from two HLA-A2 positive donors showed no cytotoxicity against any of the 14 lung cancer cell lines. CTL line TI-1 showed cytotoxicity against 1-87 but not against any of the other cell lines. Treatment of 1-87 with IFN-gamma greatly augmented the cytotoxicity of TI-1 and induced it in the other 12 CTL lines, confirming the expression of the peptide on 1-87. No cytotoxicity was induced by IFN-gamma treatment of PC-9 or OU-LC-KI. However, PC-9 and OU-LC-KI pulsed with the peptide were killed efficiently by all of the CTL lines, suggesting no expression of the peptide on those cells. A low level of cytotoxicity was induced on 11-18 but not LK87 by IFN-gamma treatment, although expression of the HLA-A2 antigen was not observed by cytofluorometry. These findings showed that expression of the HLA-A2-binding MAGE-3 peptide recognized by CTL was variable on lung cancer cell lines.

Amino Acid Sequence↗
PubMed1998

Effectiveness of simplified dentin bonding systems.

The effectiveness of newly developed commercial dentin bonding systems (SB, MB II and KB) was evaluated by measuring the contraction gap width of a resin composite restored into a cylindrical dentin cavity prepared in an extracted human molar and by measuring the tensile bond strength to the flat dentin surface. In addition, calcium loss during dentin conditioning was analyzed using electron microanalyses. An experimental dentin bonding system composed of EDTA conditioning, GM solution priming and a bonding agent containing 10-MDP was employed as a control in which it was presumed that contraction gap formation was prevented completely. However, gap formation was observed using the three commercial simplified dentin bonding systems. SEM observation showed that the gap was formed between the resin composite and the top surface of the dentin cavity wall indicating that the fracture occurred at the adhesive interface, but never inside the dentin nor inside the resin composite.

Calcium↗
PubMed1998

Cavity adaptation of resin composite in canine cavity in vivo.

The efficacy of four commercial and two experimental dentin bonding systems was examined by observing the cavity adaptation of commercial light-cured resin composites restored in the dogs scheduled to be sacrificed after a medical experiment. Before being sacrificed, a cylindrical class V cavity was prepared in each canine, and the cavity wall was treated with one of four commercial dentin bonding systems according to the manufacturers instructions followed by resin composite filling. The maximum contraction gap widths at the occlusal, gingival and axial cavity wall were measured on the cavity section 30 min after the polymerization of the resin composite under a light microscope. Contraction gap formation was completely prevented in only one of the experimental groups in which the cavity wall was primed with 35 vol% glyceryl mono-methacrylate (GM). In addition, observation of cavity adaptation in the canine in vivo was useful to estimate consistently the efficacy of the bonding systems.

Alkanes↗