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Tomoko Kobayashi

Publications and source records attributed to Tomoko Kobayashi.

At least 19 recordsLinked to original sources
PubMed2024

A rapid and simple clonality assay for bovine leukemia virus-infected cells by amplified fragment length polymorphism (AFLP) analysis.

UNLABELLED: Enzootic bovine leukosis (EBL), although eradicated in some European countries, is still the most common neoplastic disease of cattle, caused by the bovine leukemia virus (BLV). During the progression of EBL, BLV-infected cells clonally expand, and some of which result in tumor onset. The clonality of BLV-infected cells is generally evaluated with NGS or Sanger sequencing. Although these methods clearly distinguish EBL from non-EBL cases, the procedures are complex and not practical for routine veterinary diagnosis. In this study, we developed an amplified fragment length polymorphism (AFLP) analysis for BLV clonality assay (BLV-AFLP). This analysis uses restriction enzyme digestion to amplify the chimeric regions of BLV 3' linear transcribed region (LTR) and host genome through conventional polymerase chain reaction (PCR) and visualizes the results by gel-electrophoresis. The method was established using cattle samples representing different stages of the disease: BLV-uninfected, non-EBL, and EBL cattle. Non-EBL cattle showed smeared bands, indicating polyclonal proliferation, while EBL cattle showed distinct bands, indicating clonal expansion. The results of BLV-AFLP correlated well with those of previously reported methods, suggesting its efficacy in detecting clonal proliferation. The validation using blood samples of non-EBL cattle and tumor samples of EBL cattle confirmed that BLV-AFLP could effectively identify clonal proliferation in EBL samples. Moreover, the emergence of dominant clones in the tumor at later stages was successfully detected before EBL onset in some cattle, highlighting its sensitivity and potential for early detection. Overall, BLV-AFLP is suitable for practical use in the field, improving BLV management strategies and minimizing economic losses. IMPORTANCE: Enzootic bovine leukosis (EBL) is routinely diagnosed based on external manifestations at the farm, such as the presence of tumors and/or general lymph node enlargement. However, due to the nonspecific clinical manifestations of EBL, over half of EBL cases are unrecognized at the farm, with most cases being diagnosed during postmortem inspection at the slaughterhouse. Early detection and monitoring of clonal expansion are necessary for managing EBL and reducing economic losses. In this study, we developed BLV-AFLP that represents a significant advancement in the diagnosis of EBL in cattle. This method can rapidly assess the clonal proliferation of BLV-infected cells, crucial for distinguishing between asymptomatic and EBL cattle. Additionally, tracking clonal dynamics offers insights into the disease's progression, potentially providing strategies for avoiding economic losses. Overall, as BLV-AFLP is a simple and rapid test for detecting EBL, it is feasible and efficient for routine veterinary practice.

Leukemia Virus, Bovine↗
PubMed2006

Case report: Focal ablation for atrial fibrillation originating from the inferior vena cava and the posterior left atrium.

We identified a case of paroxysmal atrial fibrillation (AF) originating from inferior vena cava (IVC) and the low-posterior left atrium (LA). Both foci, the IVC and the low-posterior LA, simultaneously served not only as trigger but also as driver for maintenance of AF. During AF, the IVC and the low-posterior LA continuously demonstrated the rapid and fractionated potentials that exit into both atria with conduction block. Focal ablation for ectopic beats within the IVC and the low-posterior LA completely eliminated the storm of AF.

Aged, 80 and over↗
PubMed2006

[Antimicrobial susceptibility and mechanism of resistance to antibiotics for Escherichia coli O157 and verotoxin-producing E. coli isolated in northern Kyushu and Yamaguchi area].

The purpose of this study was to investigate the biochemical characteristics and antimicrobial susceptibility of Escherichia (E.) coli O157 and verotoxin-producing E. coli isolates from the Northern Kyushu Island and Yamaguchi area of Japan. A total of 54 isolates- 50 E. coli O157, 3 verotoxin-producing E. coli O26 and 1 verotoxin-producing E. coli O111 - were used in this study. Regarding H antigen, H7 type in E. coli O157 accounted for 98% (49/50), and residual 1 strain of E. coli O157 was untypable H type. Two of 3 E. coli O26 isolates were H11 type, residual 1 strain of E. coli O26 was untypable H type, and E. coli O111 isolate was non-motile strain. All 54 isolates were susceptible to cephems, fosfomycin, kanamycin, amikacin and co-trimoxazole. Tetracycline-resistant isolates existed in 13 of all 54 isolates, 5 of those 13 isolates had tetA, and the other 7 isolates had tetB. Eight amoxicillin-resistant isolates had TEM-1 beta-lactamase. Four of the 5 isolates that had tetA also had TEM-1 beta-lactamase. Nalidixic acid and 6 fluoroquinolone used had no insensitive or resistant isolates. Kanamycin-resistant isolates, fosfomycin- and nalidixic acid-insensitive isolates have been reported, so we must notice the antibiogram of such strains. It is important that the surveillance of antimicrobial susceptibility of enterohemorragic E. coli should be continued after this.

Amoxicillin↗
PubMed2006

An inhibitory effect of A20 on NF-kappaB activation in airway epithelium upon influenza virus infection.

Influenza is a major disease in humans. The reemergence of avian influenza A viruses has indicated that hyperinflammatory responses are closely related to the severity of disease. Influenza virus infection induces nuclear transcription factor kappaB (NF-kappaB) activation. NF-kappaB and NF-kappaB-dependent gene products promote lung inflammation and injury. Therefore, it is important to investigate the means to attenuate NF-kappaB activation. A20 is a cytoplasmic zinc finger protein that inhibits NF-kappaB activity, However, little is known about the role of A20 in influenza virus infection. Here, we have examined the role of A20 in influenza virus infection-induced NF-kappaB promoter activation in human bronchial epithelial cells. The results showed that (1) A20 protein and mRNA are inducible and expressed in the lung from mice and human bronchial epithelial cells upon influenza virus infection; (2) NF-kappaB promoter activation was induced in bronchial epithelial cells upon influenza virus infection; and (3) overexpression by transient transfection of A20 attenuated NF-kappaB promoter activation in bronchial epithelial cells. These results indicate that A20 may function as a negative regulator of NF-kappaB-mediated lung inflammation and injury upon influenza virus infection, thereby protecting the host against inflammatory response to influenza virus infection.

Animals↗
PubMed2006

Emergence and prevalence of beta-lactamase-producing Klebsiella pneumoniae resistant to cephems in Japan.

Forty-six cephem-resistant Klebsiella pneumoniae strains with minimum inhibitory concentrations>8 microg/mL for cefpodoxime and cefmetazole were selected from clinical isolates obtained between 2000 and 2002 from eight hospitals on Northern Kyushu Island, Japan. We investigated the mechanisms of resistance to cephems in these 46 K. pneumoniae isolates. The results of isoelectric focusing of beta-lactamases produced by these isolates, polymerase chain reaction for detection of various Class A, Class B and Class C beta-lactamases, and determination of the sequence of the beta-lactamase structural gene showed that most of these isolates had various types of broad-spectrum beta-lactamases. Of the 46 isolates, 2 were CMY-2 beta-lactamase producers and 41 were DHA-1 beta-lactamase producers. Forty of the 41 DHA-1 beta-lactamase producers simultaneously produced SHV-12 extended-spectrum beta-lactamase (ESBL), and the remaining isolate simultaneously produced SHV-27. Furthermore, one DHA-1 and SHV-12 beta-lactamase producer also produced IMP-1 beta-lactamase. The only broad-spectrum beta-lactamase with another isolate was IMP-1. Chromosomal DNA restriction fragment analysis using XbaI suggested that nosocomial infection due to DHA-1 and SHV-12 beta-lactamase producers had occurred at two centres. This is the first report of nosocomial infection due to DHA-1 beta-lactamase-producing K. pneumoniae including other plasmid-encoded AmpC beta-lactamases in Japan. The mechanisms of resistance of 44 of the 46 isolates to cephalosporins and cephamycins were ESBL production and/or plasmid-encoded AmpC beta-lactamase and/or IMP-1 beta-lactamase production. For two isolates, the mechanism of resistance to could not be identified. These results show that it is necessary to minimise the prevalence of these resistant strains as it will be a very serious problem if organisms producing these broad-spectrum beta-lactamases increase in clinical situations. It is important to detect these strains sooner and to perform rigorous infection control earlier.

Cephalosporins↗
PubMed2006

Two atrial reentrant tachycardias originating from the superior vena cava: electrophysiological characteristics and radiofrequency ablation.

A case with two different types of atrial reentrant tachycardia of superior vena cava (SVC) origin is presented. Recent clinical studies have shown that the origin of focal atrial tachycardia typically lies in the venous structures connecting to both atria--the coronary sinus, the superior and inferior vena cava, and the pulmonary vein. These foci have atrial muscle fiber extensions which have electrophysiological characteristics essential to generation of focal ectopic firing. However, little is known about reentrant mechanism of these venous structures. In this report, we present a case of two atrial tachycardias (SVT1 and SVT2) independently originating from the SVC. SVT1 had 430 ms of tachycardia cycle length, and SVT2 had 390 ms of tachycardia cycle length. Both of them showed the character of reentry, and their earliest activations were recorded in the SVC. They were successfully eliminated by focal radiofrequency ablation in the SVC.

Body Surface Potential Mapping↗
PubMed2006

Catheter ablation for an incessant form of antiarrhythmic drug-resistant ventricular fibrillation after acute coronary syndrome.

A 77-year-old man was admitted with an acute coronary syndrome (ACS), severe heart failure (HF), and repeated ventricular fibrillation (VF) episodes. A single premature ventricular complex (PVC) induced ventricular tachycardia (VT), which degenerated to VF reproducibly. This PVC was eliminated by catheter ablation at the left ventricular posteroseptal region where double Purkinje potentials preceding the ventricular wave had been recorded. The electrical storm disappeared, and programmable stimulation failed to induce any tachyarrhythmias after the ablation. A Purkinje fiber network-related PVC served as a trigger and as a substrate for VT and VF in a case of ACS with HF.

Aged↗
PubMed2006

Bundle brunch reentrant ventricular tachycardia with two distinct conduction patterns in a patient with complete right bundle branch block.

We report a rare case of bundle branch reentrant ventricular tachycardia [BBRVT]. A 67-year-old female was admitted for management of wide QRS tachycardia (right bundle branch block [RBBB] and a southwest axis). The mapping procedure revealed the tachycardia circuit consisted of the left anterior fascicle (LAF) as an antegrade, and the right bundle as a retrograde pathway. She presented RBBB during sinus rhythm. LAF ablation changed the tachycardia configuration to a northwest axis and prolonged the cycle length. Left posterior fascicle ablation terminated the tachycardia, and complete atrioventricular block occurred, which showed the unidirectional conduction over the right bundle.

Aged↗
PubMed2006

[Comparison of 3 commercial metallo-beta-lactamase detection kits].

Using 41 metallo-beta-lactamase producing isolates and 8 metallo-beta-lactamase nonproducing and ceftazidime-resistant isolates from Kyushu Island, metallo-beta-lactamase was detected by 3 commercial metallo-beta-lactamase detection kits, which were Metallo-beta-lactamase SMA Eiken (SMA, disk diffusion, Eiken Chemical Co.), dry plate Eiken DPD1 (DPD, two-fold serial broth microdilution, Eiken Chemical Co). and Cica beta test I/ MBL (CIC, coloring reaction, Kanto Chemical Co.). Detection rate by SMA, DPD, and CIC was 97.5, 100, and 100%. Neither method used in this study produced false-positive or false-negative results. The rates of metallo-beta-lactamase nonproducer identification were 37.5%, 62.5%, and 100% for the SMA, DPD, and CIC kits, respectivily. These three methods have the following features, SMA is useful for routine work because SMA utilizes disk diffusion, which is widely used by medical technologists, and it is the least expensive of the three kits. CIC can detect metallo-beta-lactamase after only 15 minutes and can determine the presence of non-metallo-beta-lactamase producers at a high rate. DPD can simultaneously identify the MIC of some agents. Consequently these three metallo-beta-lactamase detection kits were very useful for detecting metallo-beta-lactamase producing isolates.

Aged↗
PubMed2005

Apoptosis signal-regulating kinase 1 in leukotriene D(4)-induced activator protein-1 activation in airway smooth muscle cells.

Cysteinyl leukotrienes (LTs) are involved in allergic disorders including bronchial asthma. Transcription factor activator protein-1 (AP-1) activation is essential for cell proliferation and differentiation. LTD(4) is shown to promote human airway smooth muscle cell proliferation; however, the effect of LTD(4) on AP-1 activation in airway smooth muscle cells and the molecular mechanism in regulating AP-1 activation have not been determined. We examined the effect LTD(4) on AP-1 activation in human airway smooth muscle cells and analyzed a role of apoptosis signal-regulating kinase1 (ASK1), an upstream kinase kinase of c-Jun-NH(2)-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) in LTD(4)-induced AP-1 activation to clarify the signaling molecule regulating AP-1 activation. The results showed that LTD(4) induced AP-1 activation determined by AP-1-dependent luciferase gene activity and ASK1 phosphorylation. Transient transfection of the dominant negative form of ASK1 attenuated LTD(4)-induced AP-1 activation. In addition, LTD(4)-induced AP-1 activity was depressed in the dominant negative form of ASK1-stably transfected porcine artery endothelial cells compared to that in the parental porcine artery endothelial cells. These results indicate that LTD(4) is capable of inducing AP-1 activation and ASK1 regulates AP-1 activation in LTD(4)-stimulated airway smooth muscle cells.

Animals↗
PubMed2005

Congenital bilateral severe microphthalmia with mental retardation and cerebral palsy: chromosome aberration, 46, XY, t (2;6)(q31;q24).

Congenital bilateral anophthalmia and microphthalmia are rare conditions, with overall prevalence in one study set at 1.0 per 10,000 births. We report here a case of congenital bilateral severe microphthalmia with mental retardation and cerebral palsy. The patient was man aged 38 years with a chromosome aberration, namely a balanced translocation: 46, XY, t (2;6)(q31;q24). He had no other malformations apart from the severe microphthalmia. CT of the head showed no significant abnormal findings in the brain, but rudimentary eyeballs and external ocular muscles in the bilateral orbits. There was no family history of anophthalmia, microphthalmia, mental retardation or cerebral palsy. His mother had not used any medications or excessive alcohol during gestation. Putative genes of anophthalmia and microphthalmia reported to date include PAX6 (Glaser T et al 1994) and CHX10 (Ferda Percin E et al 2000). Further, some loci of these conditions have been reported (Graham CA et al 1991; Bessant DAR et al 1998; Morle L et al 2000: Forrester S et al 2001: Ng D et al 2002). To our knowledge, however, this is the first report of nonsyndromic microphthalmia or anophthalmia with chromosome 2q31 or 6q24 aberration. We consider that the putative gene may be located on the brake points of chromosome 2 and 6.

Abnormalities, Multiple↗
PubMed2004

Effect of preintervention remodeling type on subsequent coronary artery behavior after directional atherectomy.

To evaluate the influence of preintervention remodeling on subsequent vessel behavior after directional coronary atherectomy (DCA) under intravascular ultrasound (IVUS) guidance, serial (before and after DCA and at 6-month follow-up) IVUS data were analyzed for 246 lesions that were classified into 2 categories: positive remodeling (PR) in 77 lesions versus intermediate or negative remodeling in 169 lesions. Although the 2 groups had similar baseline characteristics, IVUS data showed that the PR group had a greater acute lumen area (LA) gain without an increased late LA loss, resulting in a greater net (acute plus late) LA gain and follow-up LA. This suggests that IVUS-guided DCA may neutralize the negative impact of preintervention PR on late vessel patency.

Aged↗
PubMed2004

Randomized, controlled trial of secondary prevention of coronary sclerosis in normocholesterolemic patients using pravastatin: final 5-year angiographic follow-up of the Prevention of Coronary Sclerosis (PCS) study.

BACKGROUND: The potential benefit of cholesterol-lowering therapy for normocholesterolemic patients with coronary artery disease (CAD) has not been clarified. The Prevention of Coronary Sclerosis (PCS) Study was designed to evaluate the effect of pravastatin on secondary prevention of progression of CAD in normocholesterolemic patients for a period of 5 years. METHODS: A total of 329 patients with CAD were enrolled. Normocholesterolemic patients were defined by a serum total cholesterol (TC) level of 180-219 mg/dl. Patients in this group were randomized into pravastatin and dietary control groups. Patients whose serum TC level fell outside the normal range were divided into a high-cholesterol reference group (TC > or = 220 mg/dl) and a low-cholesterol reference group (TC < 180 mg/dl). Patients in the pravastatin and high-cholesterol groups received pravastatin 10 mg/day. Coronary angiography was performed at baseline, 2 years, and 5 years and analyzed by quantitative coronary arteriography. Angiographic coronary progression was evaluated by minimum obstruction diameter (MOD) and mean segment diameter (MSD). RESULTS: At 5 years, change in MOD was significantly (change, P=0.033; change/years, P=0.032) less in the pravastatin group (-0.04 +/- 0.17 mm) than in the dietary control group (-0.16 +/- 0.27 mm). Although a similar trend was observed in the MSD results, the differences were not significant. CONCLUSION: Long-term angiographic data show that cholesterol-lowering therapy by pravastatin prevents progression of coronary atherosclerosis in normocholesterolemic patients with CAD.

Adult↗
PubMed2004

[A case of severe mental retardation with blepharophimosis, ptosis, microphthalmia, microcephalus, hypogonadism and short stature--the difference from Ohdo blepharophimosis syndrome].

We report a case of 13-year-old girl with short stature, microcephalus, blepharophimosis, ptosis, bilateral microphthalmia (more prominent in the right), hypogonadism, other minor anomalies, and severe mental retardation. Her mother had two spontaneous abortions. She was born as the second baby of dizygotic twins. The first baby died of diaphragm hernia and heart failure. Her body height, body weight and head circumference were below -3 SD. She did not have epicanthus inversus, hypoplastic teeth, heart anomalies, seizures, muscle weakness, and hearing loss. She was able to handle her wheelchair, but could neither understand nor speak meaningful words. When she looked at something in front of herself, she turned her face up and lifted the left eyelid with her own fingers. She had no somatic change of puberty. Laboratory and radiological examinations demonstrated a normal karyotype, normal bone age, findings of Chilaiditi syndrome, and absence of brain malformation on cranial CT. The serum levels of LH and FSH were high for age and those of estradiol and progesterone were low, suggesting immaturity of ovarian function. These findings suggested the ovarian functions might not get maturations. Hypogonadism has previously been reported in female cases of the blepharophimosis, ptosis and epicanthus inversus syndrome (BPES) type I, but not in those with the Ohdo blepharophimosis syndrome (OBS). Our case's condition differs from BPES because of the presence of mental retardation and the absence of epicanthus inversus. We also discuss the distinction from OBS, a disease entity of unknown etiology presenting with a variety of complications.

Abnormalities, Multiple↗
PubMed2004

[Two cases of adult Down syndrome treated with selective serotonin re-uptake inhibitor for behavior disorders].

Adult patients with Down syndrome show psychological symptoms and early senility. Improving their environment and dealing with their complaints and stress should first address their behavioral problems, such as self-injury, depression, aggression and outbursts. Pharmacological treatment may also be tried for behavioral disorders. Individuals with Down syndrome demonstrate neurotransmitter changes such as the loss of acetylcholine, norepinephrine, and serotonin (5-HT) with increasing age. Selective serotonin re-uptake inhibitor (SSRI) is effective for depression and panic disorders. We report here the effect of SSRI in two adult male patients with Down syndrome, 35 and 47 years of age. Self-injury in one case and aggression and outbursts in another improved after 1 week of fluvoxamine treatment, suggesting the effects of SSRI for behavioral disorders of adult Down syndrome.

Adult↗
PubMed2003

Cross-coupling reactions of (1-fluorovinyl)methydiphenylsilane(1) with aryl halides and aryl triflates.

The cesium fluoride (CsF)-assisted cross-coupling reaction of (1-fluorovinyl)methyldiphenylsilane (1) with aryl halides and aryl triflates was examined. The reaction with aryl iodides smoothly proceeded to afford the corresponding (1-fluorovinyl)arenes in the presence of a catalytic amount of CuI and Pd(PPh(3))(4) in aprotic polar solvents such as DMF, DMI, DMA, and NMP in good yields. A variety of functional groups (nitro, ester, ketone, and ether) on the aromatic rings can be tolerated under these mild conditions. Aryl iodides are superior to aryl bromides as the coupling reaction partner. The cross-coupling reaction of 1 with aryl triflates instead of aryl halides was also accomplished in the presence of tetrabutylammonium iodide (n-Bu(4)NI) as the additive under similar conditions.

Journal Article↗
PubMed2003

Evaluation of the PercuSurge Guardwire Plus Temporary Occlusion and Aspiration System during primary angioplasty in acute myocardial infarction.

Thirty patients with acute myocardial infarction (AMI) underwent primary angioplasty under distal protection of PercuSurge GuardWire Plus Temporary Occlusion and Aspiration System. Before angioplasty, protection of the distal circulation was achieved with the system, followed by balloon angioplasty and/or stenting and debris aspiration. Technical device success was 100%. Distal occlusion was well tolerated in all patients. Mean total distal occlusion time was 7.3 +/- 5.4 min. Macroscopically visible debris was aspirated from 29 cases (96.7%). Postprocedural Thrombolysis in Myocardial Infarction flow grade 3 was achieved in all cases (100%, vs. 16.7% at baseline). Myocardial blush flow grade 3 was achieved in 26 cases (86.7%). Regression of ST segment elevation >/= 50% was shown in 23 cases (76.7%). No patient developed angiographic evidence of no-reflow or distal embolization. Both angiographic and procedural success were 100%. The system is feasible, safe, and effective for distal protection against embolism during primary angioplasty in AMI.

Aged↗