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K Arakawa

Publications and source records attributed to K Arakawa.

At least 19 recordsLinked to original sources
PubMed2006

Changes in the Burgers vector of perfect dislocation loops without contact with the external dislocations.

We report the observations of a new type of changing process in the Burgers vector of dislocations by in situ transmission electron microscopy. Small interstitial-type perfect dislocation loops in bcc iron with diameters less than approximately 50 nm are transformed from a 1/2<111> loop to another 1/2<111> one or an energetically unfavorable <100> one; furthermore, a <100> loop is transformed to a 1/2<111> one. These transformations occurred on high-energy electron irradiation or simple heating without contact with external dislocations. The origin of these phenomena is discussed.

Journal Article↗
PubMed2005

Improvement of accessory symptoms of hypertension by TSUMURA Orengedokuto Extract, a four herbal drugs containing Kampo-Medicine Granules for ethical use: a double-blind, placebo-controlled study.

A double-blind, placebo-controlled study was conducted to evaluate the efficacy, safety, and utility of TSUMURA Orengedokuto Extract Granules for Ethical Use (TJ-15) as a treatment for the accessory symptoms of hypertension. Two capsules of the study drug were administered orally 3 times daily (i.e., before meals) for 8 weeks. Among 265 patients enrolled in the study, 134 were assigned to the TJ-15 group and 131 were assigned to the placebo group, of whom 204 patients (103 in the TJ-15 group and 101 in the placebo group) were included in the efficacy and utility analyze and 251 patients (128 in the TJ-15 group and 123 in the placebo group) were included in the safety analysis. Efficacy was significantly higher in the TJ-15 group based on the total score for the accessory symptoms of hypertensions which was the primary efficacy endpoint (Wilcoxon's rank sum test, p=0.013). When each accessory symptom of hypertension was assessed separately, efficacy was higher for hot flushes and facial suffusion in the TJ-15 group (Wilcoxon's rank sum test, p=0.034, and 0.022, respectively). There were no significant differences between the TJ-15 and the placebo groups with respect to the decrease of blood pressure or the antihypertensive effect. There was also no significant difference between the two groups with regard to the overall safety rating. The utility rating was significantly higher in the TJ-15 group than in the placebo group (Wilcoxon's rank sum test, p=0.016). In conclusion, TJ-15 was superior to placebo with respect to efficacy, safety, and utility for the treatment of accessory symptoms of hypertension.

Adult↗
PubMed2005

Biomonitoring of polycyclic aromatic hydrocarbons on hepatocellular carcinoma cell line.

Polycyclic aromatic hydrocarbons (PAHs) are not easily degradable and exist as persistent contaminants in water environments. In this study we collected surface sediments and water samples from five different ports around Seto Inland Sea during October 2003 to April 2004. Fifteen PAHs were detected by gas chromatography/mass spectrometer (GC-MS). Expression of CYP1A enzymes was measured by a biochemical activation of 7-ethoxy resorufin ortho-deethylase (EROD). Total water PAHs ranged from 2.5 ng/l to 132 ng/l, while sediment PAHs ranged from 296.3 ng/g to 3992.9 ng/g, which indicate low to high level of PAH pollution. Selected isomer ratios (fluoranthene/pyrene to phenanthrene/anthracene and, total molecular weight of 202/total molecular weight 202-278), and detected PAHs suggested that the origin of pollution could mostly be pyrogenic. The highest total sediment PAHs were observed at the Uno Port while the lowest were at the New Okayama Port. EROD activity implied that PAH extracted from sediment samples affected on CYP1A enzymes expression on the human hepatocellular carcinoma cell line in a short exposure time (12 hours). Relatively EROD activity showed good correlation between PAH concentration and CYP1A expression for sediment samples. The highest EROD values were observed for sediment samples at a dose of 5 ppm. In contrast water samples were at the low induction level even under the highest exposure concentration (50 ppm), except in Mizushima Port. Biomonitoring of water environments by EROD activity could be a necessary tool for understanding the effects of PAHs on living organisms at the base of cell defense.

Biological Assay↗
PubMed2003

G-language Genome Analysis Environment: a workbench for nucleotide sequence data mining.

SUMMARY: G-language Genome Analysis Environment (G-language GAE) is an open source generic software package aimed for higher efficiency in bioinformatics analysis. G-language GAE has an interface as a set of Perl libraries for software development, and a graphical user interface for easy manipulation. Both Windows and Linux versions are available. AVAILABILITY: From http://www.g-language.org/ under GNU General Public License. CD-ROMs are distributed freely in major conferences.

Database Management Systems↗
PubMed2001

A novel autosomal dominant spinocerebellar ataxia (SCA16) linked to chromosome 8q22.1-24.1.

OBJECTIVE: To characterize a distinct form of autosomal dominant cerebellar ataxia (ADCA) clinically and genetically. BACKGROUND: ADCAs are a clinically, pathologically, and genetically heterogeneous group of neurodegenerative disorders. Nine responsible genes have been identified for SCA-1, -2, -3, -6, -7, -8, -10, and -12 and dentatorubral-pallidoluysian atrophy (DRPLA). Loci for SCA-4, -5, -11, -13, and -14 have been mapped. METHODS: The authors studied a four-generation Japanese family with ADCA. The 19 members were enrolled in this study. The authors performed the mutation analysis by PCR and a genome-wide linkage analysis. RESULTS: Nine members (five men and four women) were affected. The ages at onset ranged from 20 to 66 years. All affected members showed pure cerebellar ataxia, and three patients also had head tremor. Head MRI demonstrated cerebellar atrophy without brain stem involvement. The mutation analysis by PCR excluded diagnoses of SCA-1, -2, -3, -6, -7, -8, and -12 and DRPLA. The linkage analysis suggested linkage to a locus on chromosome 8q22.1-24.1, with the highest two-point lod score at D8S1804 (Z = 3.06 at theta = 0.0). The flanking markers D8S270 and D8S1720 defined a candidate region of an approximately 37.6-cM interval. This candidate region was different from the loci for SCA-4, -5, -10, -11, -13, and -14. CONCLUSION: The family studied had a genetically novel type of SCA (SCA-16).

Adult↗
PubMed2001

Effect of coronary risk factors on arterial compensatory enlargement in japanese middle-aged patients with de novo single-vessel disease--an intravascular ultrasound study.

BACKGROUND: Compensatory enlargement (CE) of atherosclerotic human arteries has been reported; however, the pattern of arterial remodeling in response to plaque formation is not unique. HYPOTHESIS: The study was undertaken to determine the extent of coronary artery compensatory enlargement at stenotic lesions and to correlate the arterial compensatory enlargement with risk factors. METHODS: We studied 62 patients with stable angina and de novo single-vessel disease using intravascular ultrasound and obtained good images in 42 patients (68%). The vessel cross-sectional area (VA), lumen cross-sectional area (LA), and plaque cross-sectional area (PA) were measured at the lesion site and at proximal and distal reference sites. Positive CE was defined as increase in VA of lesion site > 10% compared with that of proximal reference site (CE group, n = 15); shrinkage was defined as reduction in VA of lesion site > 10% compared with that of proximal reference site (S group, n = 14); inadequate CE was defined as intermediate between CE and S (IE group, n = 13). All subjects had coronary risk factors measured before this study. RESULTS: There was no difference in VA, LA, or PA among the three groups at the proximal and distal reference sites, nor in LA at the lesion site; however, VA and PA were significantly smaller in the S group than in the other groups (p < 0.01). Of coronary risk factors, increased systolic blood pressure (SBP), increased diastolic blood pressure (DBP), and decreased high-density lipoprotein cholesterol (HDL-c) levels had the strongest association with shrinkage (p < 0.05). CONCLUSION: Hypertension and decreased HDL level may contribute to the shrinkage response in middle-aged patients with stable angina.

Aged↗
PubMed2001

MR imaging of primary malignant lymphoma in the larynx.

We present MR findings in a patient with primary laryngeal lymphoma. The MR images showed a homogeneous mass in the right supraglottic larynx extending to the true vocal cord through the paraglottic space, of which signal intensity was intermediate both on T1- and T2-weighted images. The tumor was moderately enhanced and preserved mucosal layers were demonstrated as hyperintense bands on gadolinium-enhanced fat-suppressed T1-weighted images. Primary laryngeal lymphoma should be included in the differential diagnosis for a homogeneous solid mass in the supraglottic submucosal area.

Aged↗
PubMed2001

Alcohol consumption and severity of angiographically determined coronary artery disease in Japanese men and women.

The relation of alcohol consumption to the severity of coronary atherosclerosis was examined among 323 men and 220 women who underwent coronary arteriography. Severity of coronary atherosclerosis was assessed by the number of vessels obstructed > or =75% in diameter and Gensini's severity score. Alcohol consumption was divided into 5 categories in men (never, past, 1-24, 25-49, and > or =50 ml per day) and 3 categories in women (never, past, and current). Among men, odds ratios of severe stenosis (multiple-vessel disease or Gensini's score >15) decreased substantially and significantly in all current drinking categories but without dose-response effect. There was a weak, inverse association of current alcohol consumption with one-vessel disease, but not with moderate stenosis in terms of Gensini's score (< or =15). Past drinkers showed a fairly large, but statistically nonsignificant, decrease in the odds ratios of not only severe stenosis but also of moderate stenosis. Among women, current drinkers showed a small, statistically nonsignificant decrease in the risk of severe stenosis in terms of Gensini's score. These associations with alcohol use did not change after adjustment for known coronary risk factors. The present findings add to evidence that alcohol drinking confers protection against coronary atherosclerosis.

Adult↗
PubMed2001

Effect of AVT antisense oligodeoxynucleotides on AVT release induced by hypertonic stimulation in chicks.

In birds, arginine vasotocin (AVT) and mesotocin (MT) are the neurohypophyseal hormones. AVT is known to be an avian antidiuretic hormone and is released from the neurohypophysis by dehydration or hyperosmotic stimulation. The purpose of this study was to determine whether the mechanism of AVT synthesis is related to the mechanism of hormone release from the neurohypophysis. Four-day-old chicks received an AVT antisense oligodeoxynucleotide (ODN) injection into the cerebral ventricle (icv). Following antisense administration, the chicks received hypertonic saline stimulation. Plasma levels of AVT and MT were measured by radioimmunoassays. In control birds, a hypertonic saline injection resulted in the increase of plasma AVT level. The administration of a high dose (50 microg) of antisense ODN inhibited the increase of plasma AVT level induced by the hypertonic saline stimulation. Plasma levels of MT did not change with the administration of hypertonic saline or antisense ODN. These results suggest that the mechanisms that regulate the secretion of AVT from the neurohypophysis may be coupled to the mechanisms that regulate the synthesis of AVT.

Animals↗
PubMed2001

Adult-onset hereditary sensory and autonomic neuropathy accompanied by anosmia but without skin ulceration.

We report a novel type of hereditary sensory and autonomic neuropathy (HSAN) with adult onset in a Japanese family. One male and 2 females of 6 siblings were affected. They developed anosmia initially at the ages of 20-50 years, followed by anhidrosis and sensory loss. Skin ulceration was absent. Both superficial and deep sensation were impaired in the most distal parts of all 4 limbs. Orthostatic hypotension was present in all patients. This is a unique subtype of HSAN distinct from the HSAN I-V described by Dyck.

Adult↗
PubMed2001

Improved diabetic syndrome in C57BL/KsJ-db/db mice by oral administration of the Na(+)-glucose cotransporter inhibitor T-1095.

1. The therapeutic effects of an orally active inhibitor of Na(+)-glucose cotransporter (SGLT), T-1095 (a derivative of phlorizin; 3-(benzo[b]furan-5-yl)-2',6'-dihydroxy-4'-methylpropiophenone 2'-O-(6-O-methoxycarbonyl-beta-D-glycopyranoside)) were examined in C57BL/KsJ-db/db (db/db) mice, a genetic animal model of obese type 2 diabetes. 2. The higher renal SGLT activity in db/db mice than normoglycaemic C57BL/KsJ-db/+m (db/+m) mice may support the rationale for using an SGLT inhibitor in the treatment regimen for type 2 diabetes. Both T-1095 and its metabolite, T-1095A, which had approximately 10 times more potency, effectively inhibited renal SGLT activity of these mice in vitro. 3. Single oral administration of T-1095 (10, 30, 100 mg kg(-1), p.o.) to db/db mice caused a dose-dependent reduction in blood glucose levels and a concomitant increase in glucose excretion into urine. In contrast, T-1095 only slightly affected blood glucose levels in db/+m mice. 4. Chronic administration of T-1095 (0.1% w w(-1) pellet chow, for 12 weeks) decreased blood glucose and haemoglobin A(1C) levels, and improved glucose intolerance in db/db mice. The age-related decrease in plasma insulin levels was markedly inhibited and there was a 2.5 fold increase of insulin content in the pancreas of T-1095-treated db/db mice. Food consumption was not changed, while impaired body weight gain was ameliorated by T-1095 treatment. 5. Both the development of albuminuria and the expansion of glomerular mesangial area in db/db mice were significantly suppressed by chronic T-1095 treatment, indicating the prevention of the progression of diabetic nephropathy. 6. These results demonstrate that the SGLT inhibitor T-1095 is able to improve the metabolic abnormalities and inhibit the development of diabetic complications in db/db mice. Thus, T-1095 can be used for therapy of type 2 diabetic patients.

Animals↗
PubMed2001

Obesity, body fat distribution and coronary atherosclerosis among Japanese men and women.

OBJECTIVE: To investigate the relation of the obesity and body-fat distribution with angiographically defined coronary atherosclerosis. DESIGN: Cross-sectional study in a clinical setting. SUBJECTS: Three hundred and twenty men (median age, 59 y) and 212 women (median age, 67 y) who underwent coronary angiography for suspected or known coronary heart disease at 5 cardiology departments between September 1996 and August 1997. Patients with disease duration >1 y were excluded. MEASUREMENTS: The body mass index (BMI) and the waist to hip circumference ratio (WHR) were used as main exposure variables, and either the presence of significant coronary stenosis or the Gensini's score (> or =10 vs<10) as an outcome variable, in a sex-specific multiple logistic regression analysis controlling for age, hospital, and other coronary risk factors. RESULTS: Among male patients, BMI was progressively higher with an increasing number of vessels involved (P trend=0.05); the adjusted odds ratios for the presence of significant stenosis across quartiles of BMI were 1.0 (reference), 1.1, 1.9 and 2.5 (P trend=0.02), and the positive association was more pronounced for younger patients. Among females, however, such associations were not evident. Employing the Gensini's score as an outcome gave similar results. WHR was not significantly associated with either outcome regardless of sex. CONCLUSION: These results suggested that BMI was predictive of coronary stenosis among male patients, but not among female patients. Unlike most previous studies, this study failed to detect a positive association with WHR.

Adipose Tissue↗
PubMed2001

Thyroid gland tumour, pemphigus foliaceus and myasthenia gravis in the daughter of a woman with myasthenia gravis.

We describe a rare case of pemphigus foliaceus associated with familial myasthenia gravis (MG). A 35-year-old woman developed MG during oral corticosteroid treatment for pemphigus foliaceus. She had been operated on for a thyroid gland tumour that was confirmed histopathologically to be papillary carcinoma without metastasis. At the time of treatment, her mother had had MG for 30 years and undergone thymectomy 22 years ago. A specific ELISA technique showed that antidesmoglein 1 antibody was present in the daughter. There are many reports of multiple diseases such as pemphigus, thymoma, malignancy, and other autoimmune diseases associated with MG. However, familial MG following pemphigus foliaceus has not been reported previously.

Adult↗
PubMed2001

ATP analogue binding to the A subunit induces conformational changes in the E subunit that involves a disulfide bond formation in plant V-ATPase.

Vacuolar H+-ATPase (V-ATPase) consists of a catalytic head, a stalk part and a membrane domain. We indirectly investigated the interaction between the A subunit (catalytic head) and the E subunit (stalk part) using an ATP analogue, adenosine 5'-[beta,gamma-imino]triphosphate (AMP-PNP), which holds the enzyme in the substrate-binding state. AMP-PNP treatment caused a mobility shift of the E subunit with a faster migration in SDS/polyacrylamide gel electrophoresis without a reductant, while ATP treatment did not. A mobility shift of the E subunit has been detected in several plants. As polypeptides with intramolecular disulfide bonds migrate faster than those without disulfide bonds, the mobility shift may be due to the formation of an intramolecular disulfide bond by two cysteine residues conserved among several plant species. The mobility shift may be involved in the binding of AMP-PNP to the ATP-binding site, which exists in the A and B subunits, as it was inhibited by the addition of ATP. Pretreatment with 2'-3'-O-(4-benzoylbenzoyl)-ATP (Bz-ATP), which modifies the ATP-binding site of the B subunit under UV illumination, did not inhibit the mobility shift of the E subunit caused by AMP-PNP treatment. The response of V-ATPase following the AMP-PNP binding may cause a conformational change in the E subunit into a form that is susceptible to oxidation of cysteine residues. This is the first demonstration of interaction between the A and E subunits in the substrate-binding state of a plant V-ATPase.

Adenosine Triphosphate↗
PubMed2001

Genetic, dietary, and other lifestyle determinants of plasma homocysteine concentrations in middle-aged and older Chinese men and women in Singapore.

BACKGROUND: Epidemiologic studies have identified the plasma homocysteine concentration as a risk factor for atherothrombotic vascular disease. There is little information on the distributions and determinants of homocysteine concentrations in Asian populations. OBJECTIVE: The present study was designed to examine the relations between genetic and lifestyle factors and plasma homocysteine concentrations among Chinese in Singapore. DESIGN: Plasma total homocysteine, folate, vitamin B-12, and vitamin B-6 concentrations and genetic variation at the methylenetetrahydrofolate reductase (MTHFR) locus were measured in 486 Chinese men and women aged 45-74 y in Singapore. Data on dietary and other lifestyle factors were collected in face-to-face interviews. RESULTS: Men had higher plasma concentrations of total homocysteine than women (P = 0.0001). Age was positively associated with plasma homocysteine in both sexes (P for trend = 0.0001). Plasma concentrations of folate, vitamin B-12, and vitamin B-6 were inversely associated with homocysteine concentrations. Among individuals with low plasma folate, those possessing 2 copies of MTHFR mutant alleles had significantly higher homocysteine concentrations than did those with > or = 1 copy of the wild-type allele. Cigarette smoking, daily coffee consumption, and physical inactivity were positively related to plasma homocysteine concentrations in both sexes (P < 0.05). However, these associations disappeared after adjustment for plasma folate concentrations. CONCLUSIONS: Age, sex, plasma folate, vitamin B-12 and B-6 concentrations, and MTHFR genotype are independent determinants of plasma homocysteine in middle-aged and older Chinese in Singapore. These factors combined could account for up to 40% of the total variation in homocysteine concentrations in this Asian population.

Aged↗
PubMed2001

The effects of lidocaine on superoxide production and p47 Phox translocation in opsonized zymosan-activated neutrophils.

UNLABELLED: Superoxide is generated by reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase that exists in the cell membrane of neutrophils and contains p47 phox in the enzyme complex. Superoxide is closely related to various diseases, including infection, myocardial infarction, and aspiration pneumonia. Therefore we performed this study to establish how lidocaine acts on NADPH oxidase. We examined the effects of lidocaine on superoxide production in neutrophils using the method of 2-methyl-6-phenyl-3,7-dihydro [1,2-a] pyrazin-3-one (CLA phenyl)-dependent chemiluminescence activated by opsonized zymosan (OZ). Treatment with lidocaine 15 microM suppressed OZ-activated CLA phenyl-dependent chemiluminescence by approximately 40% compared with that of OZ only-activated neutrophils. It was further demonstrated that the suppressive effect of lidocaine on superoxide production was dependent on the concentration of lidocaine. Translocation of p47 phox from the cytosol to the cell membrane was studied using immunoblot analysis with a polyclonal anti-p47 phox antibody. Lidocaine suppressed OZ-induced p47 phox translocation in a dose-dependent manner. Our results suggest that suppression of superoxide production by a therapeutic dose of lidocaine correlates strongly with suppression of p47 phox translocation. IMPLICATIONS: We report on the effects of lidocaine on superoxide production in opsonized zymosan-activated neutrophils. Lidocaine suppresses superoxide production in a dose-dependent manner. This suppression correlates strongly with the suppression of translocation of p47 phox, a new subunit of NADPH-oxidase.

Adult↗