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Biomedical subjects

K Kotani

Publications and source records attributed to K Kotani.

At least 19 recordsLinked to original sources
PubMed2006

Aberrant maspin expression in gallbladder epithelium is associated with intestinal metaplasia in patients with cholelithiasis.

OBJECTIVE: Aberrant expression of maspin protein related to DNA hypomethylation in the promoter region is frequently observed in gallbladder carcinomas, whereas the non-tumorous gallbladder epithelium is maspin negative. We investigated maspin expression in non-tumorous gallbladder epithelium in patients with cholelithiasis. METHODS: An immunohistochemical study of maspin expression was performed in 69 patients with cholelithiasis and 30 patients with gastric cancer without cholelithiasis. RESULTS: Immunoreactivity for maspin was observed in focal and patchy regions of the gallbladder epithelium. Positive immunoreactivity for maspin was significantly associated with the presence of intestinal metaplasia in patients with cholelithiasis (p<0.05). CONCLUSION: The high incidence of aberrant maspin expression in both intestinal metaplasia and carcinoma of the gallbladder supports the assumption that intestinal metaplasia of the gallbladder may predispose to gallbladder carcinoma.

Adult↗
PubMed2005

3 dB squeezing by single-pass parametric amplification in a periodically poled KTiOPO4 crystal.

We present the experimental observation of pulsed squeezed light from a degenerate optical parametric amplifier pumped by a second harmonic of a continuous-wave mode-locked Nd:YVO4 laser. With a single pass through a 10 mm long periodically poled KTiOPO4 crystal, the classical parametric gain of 11 is observed. The measured noise reduction in the quiet quadrature is 3.2 dB below the shot-noise level.

Journal Article↗
PubMed2004

Spatiotemporal patterns of movement-related fields in stroke patients.

In this study, brain functions in stroke patients and normal subjects were analyzed by observing neuromagnetic fields during button pressing tasks. The measurements included force measurement, visual stimuli presentation and magnetoencephalography (MEG). A 122-channel whole-head MEG system (Neuromag 122) was used. A total of 18 subjects (11 post-stroke and 7 control subjects) participated in the study; adequate MEG data were obtained from 3 of the patients. Equivalent current dipoles for MRFs were estimated with the following parameters: goodness of fit (> 75%), confidence volume (< 6000 mm3), and the duration of dipole (> 10 msec). In addition to the single dipole analysis, Minimum Current Estimates were applied for source estimation since neural activities for stroke patients were observed at the motor cortex of the contralateral side as well as other areas of the brain. Contralateral motor cortex was activated for the normal subjects at 50 ms prior to the force onset, whereas ipsilateral motor cortex was activated for some stroke patients and patients' dipole moments differed not only in their locations but also in their latencies, ranging from -150 to 50 ms to the force onset. The results were in agreement with the findings by PET and fMRI studies; therefore, it was implied that the compensating motor functions were shifted to neighboring areas of the brain due to the recovering motor function after stroke.

Adult↗
PubMed2004

Characterization of a point mutation in the parC gene of Mycoplasma bovirhinis associated with fluoroquinolone resistance.

Quinolone-resistant (QR) mutants of Mycoplasma bovirhinis strain PG43 (type strain) were generated by stepwise selection in increasing concentrations of enrofloxacin (ENR). An alteration was found in the quinolone resistance-determining region (QRDR) of the parC gene coding for the ParC subunit of topoisomerase IV from these mutants, but not in the gyrA, gyrB, and parE gene coding for the GyrA and GyrB subunits of DNA gyrase and the ParE subunit of topoisomerase IV. Similarly, such an alteration in QRDR of parC was found in the field isolates of M. bovirhinis, which possessed various levels of QR. The substitution of leucine (Leu) by serine (Ser) at position 80 of QRDR of ParC was observed in both QR-mutants and QR-isolates. This is the first report of QR based on a point mutation of the parC gene in M. bovirhinis.

Animals↗
PubMed2003

Isolation of Mycoplasmas from nasal swabs of calves affected with respiratory diseases and antimicrobial susceptibility of their isolates.

Nasal swabs of 293 calves were examined for Mycoplasma. The samples were collected from calves affected with respiratory diseases on 71 farms in various parts of Japan between 1996 and 1997. Mycoplasma bovirhinis was isolated from 47 of 293 calves (16.0%). Mycoplasma alkalescens, M. bovis, M. arginini, M. bovigenitalium and Acholeplasma spp. were isolated from 19 (6.5%), seven (2.4%), four (1.4%), four (1.4%) and 18 (6.1%) calves, respectively. Pasteurella multocida and P. haemolytica were isolated from 60% of Mycoplasma-positive calves. However, other bacteria were not isolated from calves. To evaluate the antimicrobial susceptibility of their isolates, 68 M. bovirhinis, 21 M. alkalescens and 10 M. bovis strains were examined for 12 antimicrobial agents. All isolates showed higher susceptibility to tiamulin than to the other drugs used in the study. However, erythromycin had no effect on any of the Mycoplasma strains studied. The field isolates were less susceptible than the type strains to some drugs, such as spiramycin, oxytetracycline and tylosin.

Animals↗
PubMed2002

Mosapride, a 5HT-4 receptor agonist, improves insulin sensitivity and glycaemic control in patients with Type II diabetes mellitus.

AIMS/HYPOTHESIS: We investigated the potential role of mosapride, a 5HT-4 receptor agonist, in glycaemic control in Type II (non-insulin-dependent) diabetic mellitus patients without autonomic neuropathy. METHODS: Thirty-four inpatients with Type II diabetes mellitus were randomly assigned to receive either mosapride (5 mg orally three times a day, n=17) or a placebo ( n=17) for 1 week (first study). Changes in blood glucose and insulin were determined basally as well as after intravenous glucose loading. Insulin sensitivity was evaluated during hyperinsulinaemic-normoglycaemic-clamp studies and by measuring the number of and the autophosphorylation of insulin receptors on the erythrocytes of patients ( n=9). Sixty-nine outpatients with Type II diabetes were similarly treated with mosapride or a placebo for 8 weeks (second study). Finally, tissue- specific expression of 5HT-4 receptors was examined by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Mosapride lowered fasting blood glucose and fructosamine concentrations ( p<0.05) (first study). It significantly increased the number of (Mosapride 3323+/-518 vs 4481+/-786 [ p<0.05], Control 4227+/-761 vs 3275+/-554 per 300 microl erythrocytes) and the tyrosine autophosphorylation (Mosapride 3178+/-444 vs 4043+/-651 [ p<0.05], Control 3721+/-729 vs 3013+/-511 insulin receptor unit) of insulin receptors, as well as glucose utilisation (Mosapride 4.92+/-0.53 vs 5.88+/-0.72 [ p<0.05], Control 4.74+/-0.65 vs 4.70+/-0.31 mg/kg x min). Mosapride treatment for 8 weeks significantly reduced fasting glucose (9.91+/-0.34 vs 8.51+/-0.34 mmol/l, p<0.05), insulin (53.2+/-4.62 vs 40.8+/-5.52 pmol/l, p<0.05) and HbA(1c) (8.61+/-0.20 vs 7.67+/-0.19%, p<0.01) concentrations (second study). The RT-PCR analysis demonstrated specific expression of 5HT-4 receptors in the muscle, but not in the liver or fat tissues. CONCLUSIONS/INTERPRETATION: Mosapride could improve insulin action at muscle and glycaemic control in Type II diabetic patients.

Base Sequence↗
PubMed2002

Pneumonitis induced by rifampicin.

An 81-year-old man was admitted to hospital with pulmonary Mycobacterium tuberculosis infection and was treated with rifampicin (RFP), isoniazid (INH), and ethambutol (EB). On day 9 he developed fever and dyspnoea. Chest radiographs showed new infiltration shadows in the right lung. Bronchoalveolar lavage (BAL) was performed and increased numbers of lymphocytes were recovered. Drug induced pneumonitis was suspected so the antituberculous regimen was discontinued and methylprednisolone was administered. The symptoms and infiltration shadows improved. INH and EB were reintroduced without any recurrence of the abnormal shadows. T cell subsets in the BAL fluid and a positive lymphocyte stimulation test for RFP suggest that RFP induced pneumonitis may be related to a complex immunological response.

Aged↗
PubMed2002

[A case of bronchioloalveolar carcinoma diagnosed by a segmental resection].

A 66-year-old man who underwent an extirpation of thymoma in stage I on September 16 1997 was followed in the outpatient clinic. In October 1998, a chest CT scan revealed a 2.0 x 1.0 cm faint frosted glass like shadow in the right S9. On September 13 1999, the patient was admitted to the hospital for close examination. Two times of transbronchial lung biopsy could not offer any clear diagnosis because the lesion was present so as to encircle the central segment of the B9 gronchus. A segmental resection (S9 + 10) under thoracotomy was performed. Intraoperative frozen section diagnosis was bronchioloalveolar carcinoma (type A according to Noguchi's classification), and a resection of the remnant lower lobe and mediastinal lymph nodes dissection (ND 2 a) were added. With expected increase in frequency of detecting early pulmonary cancer's through CT, clinical cases for which we are obliged to diagnosed the disease by segmental resection may increase, if the lesion develops in the vicinity of the hilum of lung like this case.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2002

[Recurrent tuberculous abscess in the chest wall; report of a case].

A case of recurrent tuberculous abscess in the chest wall which was successfully treated by resection of the rib and transposition with a latissimus dorsi muscle flap is reported. A 70-year-old man was admitted to the hospital for the purpose of receiving tuberculostatic treatment after an operation for tuberculous abscess in the chest wall at another hospital. When he first visited the another hospital, he had complained of a left chest wall tumor and Mycobacterium tuberculosis was isolated from the pus. After admission to the hospital, tuberculous abscess recurrenced in the left chest wall 2 months after the operation. We performed resection of the abscess, 5th and 6th ribs, as well as transposition of the latissimus dorsi muscle flap. There have been no signs of recurrence and is followed in the clinic, as of 4 months after the operation. We think that resection of the abscess, ribs, and, transposition of the muscle flap are useful methods for tuberculous abscess in the chest wall.

Abscess↗
PubMed2001

Hydrosilylation of carbonyl compounds using a PhSeSiMe(3)/Bu(3)SnH/AIBN system.

[reaction: see text] When carbonyl compounds were allowed to react with phenyl trimethylsilyl selenide and tributylstannyl hydride in the presence of a catalytic amount of AIBN as a radical initiator, the hydrosilylation of the carbonyl compounds efficiently proceeded to give the corresponding silyl ethers in moderate to good yields.

Journal Article↗
PubMed2001

Cloning, chromosomal mapping, and characteristic 5'-UTR sequence of murine cytosolic sialidase.

We have totally sequenced a cytosolic sialidase [EC 3.2.1.18] by RT-PCR from the murine thymus (murine thymic sialidase, MTS) which has a 1844-base length (encoding 385 amino acids including two sialidase motifs) and is the longest cytosolic sialidase ever reported. MTS has high and relatively low homologies with those of mammalian cytosolic sialidases from the mouse brain (99%), rat (91%), and human skeletal muscle (75%), and those of the mouse lysosomal (47%) and membrane-bound (51%) sialidases, respectively. Chromosomal mapping, being the first report of mouse cytosolic sialidase gene, showed that the MTS gene is localized to the distal part of mouse chromosome 1D and to rat chromosome 9q36. RT-PCR with the site-specific primers revealed that the coding region was expressed in all organs tested, but expressions including the 5'-UTR were barely detectable except for in the upper-thymic fraction. Also, soluble sialidase activity in the thymus was the highest of these organs. There were mRNA instability signals and AT-rich regions in 143 bp of MTS 5'-end.

5' Untranslated Regions↗
PubMed2001

New epidermal keratin genes from Xenopus laevis: hormonal and regional regulation of their expression during anuran skin metamorphosis.

Xenopus larval keratin (XLK) was isolated by gel electrophoresis of proteins of tadpole skin. Screening of an expression cDNA library of tail tissues by specific polyclonal antibodies against XLK produced XLK cDNA (xlk). Its complete nucleotide and predicted amino acid sequences revealed that XLK was a new member of type II keratin. Screening of a cDNA library of adult Xenopus skin using an oligonucleotide probe which had been designed from well-conserved N-terminal amino acid sequences of the rod domain of type I keratin produced two cDNAs, xak-a and xak-b, which were found to be new members of type I keratin gene. Northern blot analysis showed that xlk was expressed exclusively in the larval skin whereas xak-a and xak-b were expressed exclusively in the adult skin. Their expression level was regulated in a region- and metamorphic stage- dependent manner during larval skin development. mRNA in situ hybridization experiments identified the cells that expressed xlk, and xak-a and xak-b as larva- specific epidermal cells (skein cells and basal cells), and adult suprabasal epidermal cells, respectively. These three genes were found to be late responsive to thyroid hormone. Phylogenetic relationships of these keratins with known ones are discussed.

Amino Acid Sequence↗
PubMed2001

Uncoupling protein 3 (UCP3) stimulates glucose uptake in muscle cells through a phosphoinositide 3-kinase-dependent mechanism.

UCP3 is a mitochondrial membrane protein expressed in humans selectively in skeletal muscle. To determine the mechanisms by which UCP3 plays a role in regulating glucose metabolism, we expressed human UCP3 in L6 myotubes by adenovirus-mediated gene transfer and in H(9)C(2) cardiomyoblasts by stable transfection with a tetracycline-repressible UCP3 construct. Expression of UCP3 in L6 myotubes increased 2-deoxyglucose uptake 2-fold and cell surface GLUT4 2.3-fold, thereby reaching maximally insulin-stimulated levels in control myotubes. Wortmannin, LY 294002, or the tyrosine kinase inhibitor genistein abolished the effect of UCP3 on glucose uptake, and wortmannin inhibited UCP3-induced GLUT4 cell surface recruitment. UCP3 overexpression increased phosphotyrosine-associated phosphoinositide 3-kinase (PI3K) activity 2.2-fold compared with control cells (p < 0.05). UCP3 overexpression increased lactate release 1.5- to 2-fold above control cells, indicating increased glucose metabolism. In H(9)C(2) cardiomyoblasts stably transfected with UCP3 under control of a tetracycline-repressible promotor, removal of doxycycline resulted in detectable levels of UCP3 at 12 h and 2.2-fold induction at 7 days compared with 12 h. In parallel, glucose transport increased 1.3- and 2-fold at 12 h and 7 days, respectively, and the stimulation was inhibited by wortmannin or genistein. p85 association with membranes was increased 5.5-fold and phosphotyrosine-associated PI3K activity 3.8-fold. In contrast, overexpression of UCP3 in 3T3-L1 adipocytes did not alter glucose uptake, suggesting tissue-specific effects of human UCP3. Thus, UCP3 stimulates glucose transport and GLUT4 translocation to the cell surface in cardiac and skeletal muscle cells by activating a PI3K dependent pathway.

3T3 Cells↗
PubMed2001

Molecular characterization of Bombyx mori cytoplasmic polyhedrosis virus genome segment 4.

The complete nucleotide sequence of the genome segment 4 (S4) of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) was determined. The 3,259-nucleotide sequence contains a single long open reading frame which spans nucleotides 14 to 3187 and which is predicted to encode a protein with a molecular mass of about 130 kDa. Western blot analysis showed that S4 encodes BmCPV protein VP3, which is one of the outer components of the BmCPV virion. Sequence analysis of the deduced amino acid sequence of BmCPV VP3 revealed possible sequence homology with proteins from rice ragged stunt virus (RRSV) S2, Nilaparvata lugens reovirus S4, and Fiji disease fijivirus S4. This may suggest that plant reoviruses originated from insect viruses and that RRSV emerged more recently than other plant reoviruses. A chimeric protein consisting of BmCPV VP3 and green fluorescent protein (GFP) was constructed and expressed with BmCPV polyhedrin using a baculovirus expression vector. The VP3-GFP chimera was incorporated into BmCPV polyhedra and released under alkaline conditions. The results indicate that specific interactions occur between BmCPV polyhedrin and VP3 which might facilitate BmCPV virion occlusion into the polyhedra.

Amino Acid Sequence↗
PubMed2001

Glucose toxicity and the development of diabetes in mice with muscle-specific inactivation of GLUT4.

Using cre/loxP gene targeting, transgenic mice with muscle-specific inactivation of the GLUT4 gene (muscle GLUT4 KO) were generated and shown to develop a diabetes phenotype. To determine the mechanism, we examined insulin-stimulated glucose uptake and metabolism during hyperinsulinemic-euglycemic clamp in control and muscle GLUT4 KO mice before and after development of diabetes. Insulin-stimulated whole body glucose uptake was decreased by 55% in muscle GLUT4 KO mice, an effect that could be attributed to a 92% decrease in insulin-stimulated muscle glucose uptake. Surprisingly, insulin's ability to stimulate adipose tissue glucose uptake and suppress hepatic glucose production was significantly impaired in muscle GLUT4 KO mice. To address whether these latter changes were caused by glucose toxicity, we treated muscle GLUT4 KO mice with phloridzin to prevent hyperglycemia and found that insulin-stimulated whole body and skeletal muscle glucose uptake were decreased substantially, whereas insulin-stimulated glucose uptake in adipose tissue and suppression of hepatic glucose production were normal after phloridzin treatment. In conclusion, these findings demonstrate that a primary defect in muscle glucose transport can lead to secondary defects in insulin action in adipose tissue and liver due to glucose toxicity. These secondary defects contribute to insulin resistance and to the development of diabetes.

Adipose Tissue↗
PubMed2001

Detection of mycoplasma in mastitic milk by PCR analysis and culture method.

Mycoplasma alkalescens, M. bovigenitalium, M. bovirhinis and M. bovis were directly detected from milk specimens by a polymerase chain reaction (PCR) when milk specimens were centrifuged and treated with mycoplasmal lysis buffer. The sensitivity of this PCR method was 110 to 1,400 colony forming units (CFU). This method was useful for the detection of mycoplasmas in milk specimens from cows at an early stage of mycoplasmal mastitis since a small amount of mycoplasma could be detect in milk without culture. The results were available within 12 hr, which is faster than conventional culture techniques. M. bovirhinis was detected in more than 70% of mastitic milk specimens when mycoplasmas were detected in milk specimens from 30 cows with mastitis by this PCR method.

Animals↗
PubMed2001

Visceral fat is a major contributor for multiple risk factor clustering in Japanese men with impaired glucose tolerance.

OBJECTIVE: The significance of abdominal visceral fat accumulation was evaluated in Japanese men with impaired glucose tolerance (IGT). RESEARCH DESIGN AND METHODS: The IGT subjects (n = 123) were aged 55 +/- 9 years with a BMI of 24 +/- 3 kg/m(2). The 148 control subjects with normal glucose tolerance (NGT) were matched for age and BMI. IGT and NGT were classified according to the 1985 World Health Organization criteria. Abdominal fat distribution was analyzed by computed tomography at umbilical level. Plasma lipid, glucose, and insulin concentrations and blood pressure (BP) were measured. RESULTS: In subjects with IGT, the average visceral fat area (VFA) was significantly greater than in subjects with NGT. Fasting insulin, the sum of insulin concentrations during an oral glucose tolerance test, insulin resistance according to a homeostasis model assessment for insulin resistance (HOMA-IR), systolic BP, and serum triglyceride were significantly higher, whereas the DeltaI(30-0)/DeltaG(30-0) was significantly lower, in subjects with IGT. Subjects with IGT and NGT were then divided into three subgroups according to the number of risk factors they possessed (dyslipidemia, hypertension, neither, or both). In both IGT and NGT subjects, BMI, VFA, subcutaneous fat area, fasting insulin, HOMA-IR, and insulin secretion of the homeostasis model assessment were significantly higher in the double-risk factor subgroup than in the no-risk factor subgroup, and VFA was a potent and independent variable in association with the presence of a double risk factor. CONCLUSIONS: Visceral fat accumulation is a major contributor for multiple risk factor clustering in Japanese men with IGT and NGT.

Adipose Tissue↗