Search PubMed⌕ Search

Biomedical subjects

K Tamura

Publications and source records attributed to K Tamura.

At least 307 records · Page 17Linked to original sources
PubMed1999

Assessment of right artrial mapping and P wave-triggered signal-average in patients with paroxysmal atrial fibrillation.

To assess right atrial mapping and P wave-triggered signal-averaged electrocardiogram (ECG) in patients with paroxysmal atrial fibrillation (PAF), this study examined right atrial electrograms using atrial mapping and parameters by P wave-triggered signal-averaged ECG in 39 patients without sick sinus syndrome. Subjects were divided into those with PAF (n = 13; 60+/-13 years old) and a control group (n = 26; 49+/-19 years old). The total number of abnormal right atrial electrograms per patient was significantly greater in the PAF group (3.2+/-1.9) than in the control group (1.1+/-0.9; P < .001). The longest duration of right atrial electrogram in the PAF group tended to be greater than that in the control group (P = .06). The filtered P wave duration was significantly longer in the PAF group than in the control group (144+/-21 vs 125+/-14 ms [P < .002]). The values of the root mean square of P wave-triggered signal-averaged ECG 15 ms from the onset (RMSi 15) and 20 ms from the offset (RMSe 20) were significantly lower in the PAF group (1.1+/-0.4 microV, 1.4+/-0.5 microV) than in the control group (1.9+/-1.1 microV [P < .02], 2.1+/-0.9 microV [P < .01]). The total number of right atrial electrograms in patients with RMSi 15 of < or =1.5 microV was significantly greater than in patients with RMSi 15 of >1.5 microV (2.2+/-1.8 vs 1.3+/-1.3 [P < .05]). Thus, the total number of abnormal right atrial electrograms per patient, the total filtered P wave duration, RMSi 15, and RMSe 20 may be good indices of PAF in patients without sick sinus syndrome. RMSi 15 may reflect the total number of the abnormal right atrial electrograms per patient.

Atrial Fibrillation↗
PubMed1999

Heart rate variability and left ventricular dilatation early after myocardial infarction.

To assess clinically whether alterations of autonomic tone precede left ventricular dilatation, heart rate variability and early left ventricular dilatation after a first myocardial infarction were assessed. Low-frequency power (LF), high-frequency power (HF), and total power (TP) were obtained by ambulatory electrocardiogram on day 1 in 53 patients with a first acute myocardial infarction. Left ventricular end-diastolic volume determined by echocardiography was obtained on day 1 and day 14. Stepwise linear regression analysis was used to assess the associations of early left ventricular dilatation with heart rate variability adjusted for clinical variables. Higher LF and TP were significantly associated with early left ventricular dilatation after adjustment for age, sex, site of myocardial infarction, acute revasucularization, peak creatine kinase level, history of hypertension, and use of angiotensin-converting enzyme inhibitors and beta-blockers. Higher LF and TP preceded early left ventricular dilatation after myocardial infarction.

Echocardiography↗
PubMed1999

[A successfully treated parkinsonian patient with neuroleptic malignant syndrome complicated by status epilepticus and disseminated intravascular coagulation].

A 57-year-old woman with a 7-year history of Parkinson's disease was admitted to our hospital because of a high fever, disturbance of consciousness, increased muscular rigidity, tachycardia and hyperhidosis after she stopped taking her prescribed levodopa + carbidopa (Menesit) 400 mg/day. In the laboratory examinations, the erythrocyte sedimentation rate was 109 mm/h, thrombocytes 7.8 x 10(4)/mm3, fibrinogen 457 mg/dl, FDP 74.8 micrograms/dl, thus suggesting disseminated intravascular coagulation (DIC). According to her biochemical examination, the serum AST (253 IU/l), ALT (178 IU/l), CK (7115 IU/l) and BUN (25 mg/dl) levels were all increased. These laboratory data and the clinical course indicated the patient to be suffering from neuroleptic malignant syndrome (NMS) with DIC. She was diagnosed to have NMS associated with DIC. She was treated with dantrolene sodium, bromocriptine, and gabexate mesilate, and her symptoms thereafter gradually improved. On day 7, she developed status epilepticus in spite of the clinical improvement in her symptoms of NMS and DIC including a clouding of consciousness. The status epilepticus was also attenuated by the use of thiamylal sodium. Patients with Parkinson's disease associated with NMS are considered to have a low incidence of DIC, status epilepticus, and in Japan this may be the first case report of the successful treatment of NMS with DIC and status epilepticus in a patient with Parkinson's disease.

Anticoagulants↗
PubMed1999

[A case of recurrent ampullary carcinoma of the papilla of Vater, in which a complete response was induced by combination therapy using radiotherapy and oral chemotherapy employing UFT and cyclophosphamide].

A 38-year-old male patient underwent a pylorus-preserving pancreatoduodenectomy for an ampullary carcinoma of the papilla of Vater. One year after surgery a regular examination with CT and an echogram revealed a solitary recurrent tumor at a lymph node near the superior mesenteric artery. He was treated with radiotherapy at a total of 60 Gy and chemotherapy with UFT at 300 mg/day daily and oral administration of cyclophosphamide at 50 mg/day every other day. Four months after the initiation of the therapy the tumor had completely disappeared and the objective response was evaluated as a CR. The patients is now disease-free and continues to be treated with oral UFT and cyclophosphamide on an outpatient basis.

Administration, Oral↗
PubMed1999

[Home medical care from our hospital].

From April, 1996 to March, 1999, our hospital provided home medical care on a 24-hour basis for fifty patients with advanced or terminal cancer. Eventually, twenty-four patients died at home and twenty-six in the hospital. Stability of health status, the presence of willing and able caregivers, as well as a greater number of house-calls are suggested factors in facilitating a death at home. However, the patients who died in the hospital were obliged to readmit themselves until the time of death due to caregivers' reasons such as fatigue, emotional stress and/or health problems. In addition to timely availability and accessibility of respite care, psychosocial support for family caregivers by liaison nurses remains an issue to be solved in future.

Caregivers↗
PubMed1999

[Reliability of disc-diffusion susceptibility testing for arbekacin, vancomycin and teicoplanin against methicillin-resistant Staphylococcus aureus].

We investigated the differences in judgments among four disc-diffusion methods on susceptibility testing of arbekacin (ABK), vancomycin (VCM) and teicoplanin (TEIC) against 37 strains of methicillin-resistant Staphylococcus aureus (MRSA). These results were compared with minimum inhibitory concentrations (MICs) obtained from micro broth-dilution method. A marked difference was noted in the judgment of susceptibility to TEIC in Tri-disc method, that is 2 strains (5.4%) fell into sensitive (+3) 34 strains (91.9%) into moderately sensitive (+2) and 1 strain (2.7%) into moderately resistant (+), while in Sensi-disc method all strains fell into sensitive (S). According to the MICs, no strain of the MRSA tested revealed resistance to ABK, VCM and TEIC. Consequently, these three antimicrobial agents were thought to be effective on MRSA infections. From these results, we concluded that Tri-disc method for glycopeptide against MRSA, especially for TEIC, is not recommendable as a disc-diffusion method in susceptibility testing.

Aminoglycosides↗
PubMed1999

Molecular and clinical study of familial adenomatous polyposis for genetic testing and management.

Familial adenomatous polyposis (FAP) is an inherited predisposition to colorectal cancer characterized by the development of numerous adenomatous polyps, predominantly in the colorectal region. Germline mutations of the adenomatous polyposis coli (APC) gene are responsible for familial adenomatous polyposis. We examined germline mutations of the APC gene and clinical features among eighty-seven individuals who consisted of thirty-nine FAP-patients, thirty-seven of their family members with a 1 in 2 risk of predisposition to this disease, and eleven normal persons. We accurately identified nine heterozygotes, among individuals with a 1 in 2 risk by genetic testing, without the uncertainty of the recurrence risk calculated by Bayes' theorem. Six of the nine heterozygotes were confirmed to have colorectal polyps by colonoscopic examination. Since they were diagnosed at 12.7 years-of-age on average, and were no more than 20 years old, they could be treated to prevent colorectal cancer. Based on the genotype-phenotype correlation, we concluded that the germline mutations responsible for the sparse polyps phenotype of FAP-patients tend to locate from codon 1055 in the proximal region of the APC gene, while those for the profuse type locate from codon 1102 in the distal region. Among the thirty-nine FAP-patients, we found that those with the germline mutations within codon 1055 and codon 1262 had colorectal carcinomas of an advanced stage, at a high rate (71.4%). Special attention and aggressive intervention is needed in these patients and relatives at risk. With reasonable and appropriate management, it should be possible to prolong and improve the quality of life of those family members both affected and at risk.

Adenomatous Polyposis Coli↗
PubMed1999

Expression and possible functional role of the beta3-adrenoceptor in human and rat detrusor muscle.

PURPOSE: To investigate the presence of the beta3-adrenoceptor (beta3-AR) in human and rat detrusor muscle and the usefulness of beta3-AR agonists as drugs for the treatment of urinary frequency. MATERIALS AND METHODS: FK175, ethyl [(S)-8-[(R)-2-(3-chlorophenyl)-2-hydroxyethylamino]-6,7,8,9-tetrah ydro-5H-benzocyclohepton-2-yloxy]acetate monohydrochloride monohydrate, was used as a beta3-AR selective agonist. The expression of beta-AR subtypes (beta1-, beta2-, beta3-AR) mRNA was investigated in rat and human detrusor muscle by RT-PCR. Beta3-AR agonist induced cyclic AMP (cAMP) levels were measured in rat detrusor muscle strips. The relaxation response produced by a beta3-AR agonist was measured in a KCl induced tonic contraction model in rat detrusor muscle strips. The effect of a beta3-AR agonist on urinary bladder function was investigated by cystometry using a conscious rat model of urinary frequency. RESULTS: beta3-AR mRNA was substantially expressed in both rat and human detrusor muscles. The beta3-AR agonist, FK175 (10(-7) M), increased the cAMP level by 30% in rat detrusor muscle. In isolated rat detrusor muscle strips contracted with KCl, the beta3-AR agonist, FK175 (10(-8) to 10(-4) M), produced a concentration-dependent relaxation. Moreover, although the relaxation induced with FK175 was blocked by the non-selective beta-AR antagonist, bupranolol, it was unaffected by ether the beta1-AR selective antagonist, CGP 20712A, or the beta2-AR selective antagonist, ICI 118551, suggesting that FK175 induced the relaxation via the beta3-AR. Furthermore, in the rat model, the orally administered beta3-AR agonist, FK175 (10 mg./kg.) significantly increased bladder capacity with no change of micturition pressure or threshold pressure. CONCLUSIONS: These results suggest that beta3-AR agonists may be effective in the treatment of urinary frequency.

Adrenergic beta-Agonists↗
PubMed1999

[Pilot late phase II study of KRN8602 (MX2), a novel anthracycline derivative, for acute leukemia--a dose finding study in combination].

In order to determine the clinically optimal dose of KRN8602, a new anthracycline derivative, in combination therapy for acute leukemia, we performed a pilot late phase II study in combination with cytarabine (Ara-C) for acute myelogenous leukemia (AML), and with vincristine (VCR) and prednisolone (PSL) for acute lymphocytic leukemia (ALL). KRN8602 was given at a dose of 12 or 15 mg/m2 for 5 consecutive days, Ara-C at a dose of 100 mg/m2 for 7 consecutive days, VCR 1.4 mg/m2 (max. 2.0 mg/body) weekly for 4 weeks, and PSL 40 mg/m2 for principally 28 consecutive days. Of 14 patients with relapsed or refractory leukemia entered in the study, thirteen patients were evaluable for safety and 12 were evaluable for response. In AML, there was 1 partial response (PR) in 4 patients at a dose of 12 mg/m2. Against 1 complete response (CR) and 3 PRs in 4 patients at a dose of 15 mg/m2. In ALL, there was 1 PR in 1 case at a dose of 12 mg/m2, and 1 CR and 2 PR in 3 at a dose of 15 mg/m2. Major toxicities were nausea/vomiting and anorexia, but incidences and grades of toxicities were not dose-dependent, and all toxicities were tolerable and manageable. From these results it is concluded that the optimal dose of KRN8602 is 15 mg/m2 for 5 consecutive days in combination with Ara-C for AML, and with VCR and PSL for ALL.

Adult↗
PubMed1998

Expression of Msx genes in regenerating and developing limbs of axolotl.

Msx genes, homeobox-containing genes, have been isolated as homologues of the Drosophila msh gene and are thought to play important roles in the development of chick or mouse limb buds. We isolated two Msx genes, Msx1 and Msx2, from regenerating blastemas of axolotl limbs and examined their expression patterns using Northern blot and whole mount in situ hybridization during regeneration and development. Northern blot analysis revealed that the expression level of both Msx genes increased during limb regeneration. The Msx2 expression level increased in the blastema at the early bud stage, and Msx1 expression level increased at the late bud stage. Whole mount in situ hybridization revealed that Msx2 was expressed in the distal mesenchyme and Msx1 in the entire mesenchyme of the blastema at the late bud stage. In the developing limb bud, Msx1 was expressed in the entire mesenchyme, while Msx2 was expressed in the distal and peripheral mesenchyme. The expression patterns of Msx genes in the blastemas and limb buds of the axolotl were different from those reported for chick or mouse limb buds. These expression patterns of axolotl Msx genes are discussed in relation to the blastema or limb bud morphology and their possible roles in limb patterning.

Ambystoma↗
PubMed1998

Fibronectin stimulates transcription of the platelet-derived growth factor beta-receptor in cultured rat aortic smooth muscle cells.

Fibronectin seems to play an important role in promoting the characteristic changes of vascular smooth muscle cells in diabetes mellitus including overexpression of the platelet-derived growth factor beta-receptor. To determine the regulatory mechanism of the beta-receptor by fibronectin, we have analyzed the effect of fibronectin on the expression of the beta-receptor in cultured rat aortic smooth muscle cells using the beta-receptor promoter/luciferase expression vector system. Fibronectin was found to stimulate the expression of the beta-receptor at the transcriptional level. Both a MEK1 inhibitor PD98059 and a tyrosine kinase inhibitor herbimycin A significantly inhibited the fibronectin-stimulated receptor transcription. Herbimycin A also completely inhibited the fibronectin-stimulated increase in tyrosine phosphorylation of focal adhesion kinase. These data suggest the involvement of the integrin-mediated mitogen-activated protein kinase pathway downstream of fibronectin stimulation in the activation process of the beta-receptor promoter.

Animals↗
PubMed1998

Novel calcium antagonists with both calcium overload inhibition and antioxidant activity. 1. 2-(3, 5-di-tert-butyl-4-hydroxyphenyl)-3-(aminopropyl)thiazolidinones.

A series of 2-(3, 5-di-tert-butyl-4-hydroxyphenyl)-3-(aminopropyl)thiazolidinones was synthesized in order to explore novel calcium antagonists with potent antiischemic activity. These compounds were designed to have, in addition to Ca2+ antagonistic activity, both Ca2+ overload prevention and antioxidant activity in one molecule. These three kinds of activity were evaluated by using a K+-depolarized rat aorta, a veratridine-induced Ca2+ overload model of rat cardiomyocytes, and a soybean lipoxygenase-induced lipid peroxidation model of rabbit low-density lipoprotein, respectively. In particular, 2-(3, 5-di-tert-butyl-4-hydroxyphenyl)-3-[3-[N-methyl-N-[2-[3, 4-(methylenedioxy)phenoxy]ethyl]amino]propyl]-1,3-thiazolidin-4-on e (7o) was found to be highly potent and possessed a well-balanced combination of these actions in vitro.

Animals↗
PubMed1998

Mechanism of angiotensin II-mediated regulation of fibronectin gene in rat vascular smooth muscle cells.

This study was performed to investigate a mechanism of angiotensin II (Ang II)-mediated activation of the fibronectin (FN) gene in rat vascular smooth muscle cells. Actinomycin D and CV11974 completely inhibited Ang II-mediated increase in FN mRNA levels. Inhibitors of protein kinase C (PKC), protein-tyrosine kinase (PTK), phosphatidylinositol-specific phospholipase C, Ras, phosphatidylinositol 3-kinase, p70 S6 kinase, and Ca2+/calmodulin kinase also decreased Ang II-induced activation of FN mRNA. In contrast, cycloheximide; PD123319; or inhibitors of Gi, protein kinase A, or mitogen-activated protein kinase kinase did not affect the induction. FN promoter contained a putative AP-1 binding site (rFN/AP-1; -463 to -437), and the results of a transient transfection and electrophoretic mobility shift assay showed that Ang II enhanced rFN/AP-1 activity. CV11974 and inhibitors of PKC or PTK suppressed Ang II-mediated increases in rFN/AP-1 activity, although neither PD123319 nor a protein kinase A inhibitor affected the induction. Furthermore, mutation of rFN/AP-1 that disrupted nuclear binding suppressed Ang II-induced transcription in the native FN promoter (-1908 to +136) context. Thus, Ang II activates transcription of the FN gene through the Ang II type 1 receptor in vascular smooth muscle cells, at least in part, via the activation of AP-1 by a signaling mechanism dependent on PKC and PTK.

Angiotensin II↗
PubMed1998

Distinct roles of oncostatin M and leukemia inhibitory factor in the development of primordial germ cells and sertoli cells in mice.

Leukemia inhibitory factor (LIF) stimulates the growth of primordial germ cells (PGCs) in mouse embryo. However, as neither mice lacking LIF nor mice lacking the LIF receptor show defects in PGC growth, an alternate cytokine for PGC growth has been postulated. We investigated the role of mouse oncostatin M (mOSM), which is structurally and functionally related to LIF, in germ cell development. While LIF enhanced the survival of migratory as well as postmigratory PGCs, mOSM acted only on the postmigratory PGCs. Consistent with its biological activity, mOSM was found to be expressed in developing gonads. In the male, Sertoli cells in neonatal testis express mOSM; however, its expression is downregulated in adult testes. Moreover, mOSM enhanced the proliferation of Sertoli cells derived from neonatal testes in vitro more than human OSM or LIF. In contrast, postnatal ovaries do not express mOSM. These results indicate that mOSM is a stage- and sex-specific autocrine growth factor for Sertoli cells.

Animals↗